Altered Heart Rate Variability During Gaming in Internet Gaming Disorder.

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Lee, Deokjong; Hong, Sung Jun; Jung, Young-Chul; Park, Jinsick; Kim, In Young; Namkoong, Kee

2018-04-01

Internet gaming disorder (IGD) is characterized by addiction to online gaming and reduced executive control, particularly when individuals are exposed to gaming-related cues. Executive control can be measured as vagally mediated heart rate variability (HRV), which corresponds to variability in the time interval between heart beats. In this study, we investigated whether individuals with IGD have altered HRV while playing online games. We hypothesized that while gaming, individuals with IGD would exhibit phasic suppression of vagally mediated HRV, which would reflect executive control dysfunction during game play. To test this, we measured the changes of HRV when young males with IGD were engaged in real-time online gaming. The changes of HRV were associated with the severity of IGD assessed by self-reports and prefrontal gray matter volume (GMV) calculated by voxel-based morphometry. We included 23 IGD subjects and 18 controls in our analyses. Changes in HRV were not statistically different between IGD subjects and controls. Within the IGD group, however, subjects showed significant decreases in high-frequency (HF) HRV during gaming. Furthermore, the degree of decrease correlated with IGD severity and prefrontal GMV. Importantly, this phasic suppression of HF-HRV in response to gaming did not occur in control subjects. In conclusion, young males with IGD showed an altered HRV response while playing an online game, reflecting their difficulties in executive control over gaming. The dynamics between executive control and reward seeking may be out of balance during game play in IGD.

Hyperthyroidism is characterized by both increased sympathetic and decreased vagal modulation of heart rate: evidence from spectral analysis of heart rate variability.

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Chen, Jin-Long; Chiu, Hung-Wen; Tseng, Yin-Jiun; Chu, Woei-Chyn

2006-06-01

The clinical manifestations of hyperthyroidism resemble those of the hyperadrenergic state. This study was designed to evaluate the impact of hyperthyroidism on the autonomic nervous system (ANS) and to investigate the relationship between serum thyroid hormone concentrations and parameters of spectral heart rate variability (HRV) analysis in hyperthyroidism. Thirty-two hyperthyroid Graves' disease patients (mean age 31 years) and 32 sex-, age-, and body mass index (BMI)-matched normal control subjects were recruited to receive one-channel electrocardiogram (ECG) recording. The cardiac autonomic nervous function was evaluated by the spectral analysis of HRV, which indicates the autonomic modulation of the sinus node. The correlation coefficients between serum thyroid hormone concentrations and parameters of the spectral HRV analysis were also computed. The hyperthyroid patients revealed significant differences (P hyperthyroidism in 28 patients, all of the above parameters were restored to levels comparable to those of the controls. In addition, serum thyroid hormone concentrations showed significant correlations with spectral HRV parameters. Hyperthyroidism is in a sympathovagal imbalanced state, characterized by both increased sympathetic and decreased vagal modulation of the heart rate. These autonomic dysfunctions can be detected simultaneously by spectral analysis of HRV, and the spectral HRV parameters could reflect the disease severity in hyperthyroid patients.

Negative Affectivity, Depression, and Resting Heart Rate Variability (HRV as Possible Moderators of Endogenous Pain Modulation in Functional Somatic Syndromes

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Maaike Van Den Houte

2018-03-01

Full Text Available Background: Several studies have shown that patients with functional somatic syndromes (FSS have, on average, deficient endogenous pain modulation (EPM, as well as elevated levels of negative affectivity (NA and high comorbidity with depression and reduced resting heart rate variability (HRV compared to healthy controls (HC. The goals of this study were (1 to replicate these findings and (2 to investigate the moderating role of NA, depression, and resting HRV in EPM efficiency within a patient group with fibromyalgia and/or chronic fatigue syndrome (CFS. Resting HRV was quantified as the root mean square of successive differences between inter-beat intervals (RMSSD in rest, a vagally mediated time domain measure of HRV.Methods: Seventy-eight patients with fibromyalgia and/or CFS and 33 HC completed a counter-irritation paradigm as a measure of EPM efficiency. Participants rated the painfulness of electrocutaneous stimuli (of individually calibrated intensity on the ankle before (baseline phase, during (counter-irritation phase and after (recovery phase the application of a cold pain stimulus on the forearm. A larger reduction in pain in the counter-irritation phase compared to the baseline phase reflects a more efficient EPM.Results: In contrast to our expectations, there was no difference between pain ratings in the baseline compared to counter-irritation phase for both patients and HC. Therefore, reliable conclusions on the moderating effect of NA, depression, and RMSSD could not be made. Surprisingly, patients reported more pain in the recovery compared to the counter-irritation and baseline phase, while HC did not. This latter effect was more pronounced in patients with comorbid depression, patients who rated the painfulness of the counter-irritation stimulus as high and patients who rated the painfulness of the electrocutaneous stimuli as low. We did not manage to successfully replicate the counter-irritation effect in HC or FSS patients

Resting heart rate variability is associated with ex-Gaussian metrics of intra-individual reaction time variability.

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Spangler, Derek P; Williams, DeWayne P; Speller, Lassiter F; Brooks, Justin R; Thayer, Julian F

2018-03-01

The relationships between vagally mediated heart rate variability (vmHRV) and the cognitive mechanisms underlying performance can be elucidated with ex-Gaussian modeling-an approach that quantifies two different forms of intra-individual variability (IIV) in reaction time (RT). To this end, the current study examined relations of resting vmHRV to whole-distribution and ex-Gaussian IIV. Subjects (N = 83) completed a 5-minute baseline while vmHRV (root mean square of successive differences; RMSSD) was measured. Ex-Gaussian (sigma, tau) and whole-distribution (standard deviation) estimates of IIV were derived from reaction times on a Stroop task. Resting vmHRV was found to be inversely related to tau (exponential IIV) but not to sigma (Gaussian IIV) or the whole-distribution standard deviation of RTs. Findings suggest that individuals with high vmHRV can better prevent attentional lapses but not difficulties with motor control. These findings inform the differential relationships of cardiac vagal control to the cognitive processes underlying human performance. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Autonomic dysregulation in burnout and depression: evidence for the central role of exhaustion.

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Kanthak, Magdalena K; Stalder, Tobias; Hill, LaBarron K; Thayer, Julian F; Penz, Marlene; Kirschbaum, Clemens

2017-09-01

Objectives Given the important role of the autonomic nervous system (ANS) in stress regulation, astonishingly little is known about ANS functioning in burnout, a condition arising after prolonged exposure to work-related stress. The current study sought to investigate ANS modulation, as indexed by vagally-mediated heart rate variability (HRV), in relation to burnout symptomatology to (i) distinguish associations between the three dimensions of burnout [emotional exhaustion (EE), cynicism, reduced personal accomplishment] and (ii) investigate overlap in associations with depressive symptomatology. Methods Assessments of vagally-mediated HRV (ie, root mean square of successive differences, RMSSD) were conducted in a large population-based sample from the Dresden Burnout Study [N=410, mean age 42.2, standard deviation (SD) 11.2 years; 33.4% male]. Vagally-mediated HRV was assessed for 90 seconds during an emotionally-arousing situation (venipuncture, recumbent), a 335-second recumbent recovery period, and a 335-second seated resting condition. Results Results from multiple linear regression analyses revealed that EE was negatively related to RMSSD during venipuncture (=β -0.11, P=0.03) and the seated rest (β= -0.09, P=0.04) even after accounting for established ANS modulators (eg, age, body mass index). This pattern was not observed for the other dimensions of burnout. Exploratory analyses of depressive symptomatology further revealed that RMSSD was significantly and inversely associated with burnout-related symptoms but not with the core criteria of depression (eg, depressed mood). Conclusions This study presents evidence for a link between exhaustion and reduced vagal function, both in burnout and depression, suggesting that ANS modulations may not be disorder-specific but rather a psychophysiological correlate of an underlying feature shared by both conditions.

Modulation of experimental arthritis by vagal sensory and central brain stimulation.

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Bassi, Gabriel Shimizu; Dias, Daniel Penteado Martins; Franchin, Marcelo; Talbot, Jhimmy; Reis, Daniel Gustavo; Menezes, Gustavo Batista; Castania, Jaci Airton; Garcia-Cairasco, Norberto; Resstel, Leonardo Barbosa Moraes; Salgado, Helio Cesar; Cunha, Fernando Queiróz; Cunha, Thiago Mattar; Ulloa, Luis; Kanashiro, Alexandre

2017-08-01

Articular inflammation is a major clinical burden in multiple inflammatory diseases, especially in rheumatoid arthritis. Biological anti-rheumatic drug therapies are expensive and increase the risk of systemic immunosuppression, infections, and malignancies. Here, we report that vagus nerve stimulation controls arthritic joint inflammation by inducing local regulation of innate immune response. Most of the previous studies of neuromodulation focused on vagal regulation of inflammation via the efferent peripheral pathway toward the viscera. Here, we report that vagal stimulation modulates arthritic joint inflammation through a novel "afferent" pathway mediated by the locus coeruleus (LC) of the central nervous system. Afferent vagal stimulation activates two sympatho-excitatory brain areas: the paraventricular hypothalamic nucleus (PVN) and the LC. The integrity of the LC, but not that of the PVN, is critical for vagal control of arthritic joint inflammation. Afferent vagal stimulation suppresses articular inflammation in the ipsilateral, but not in the contralateral knee to the hemispheric LC lesion. Central stimulation is followed by subsequent activation of joint sympathetic nerve terminals inducing articular norepinephrine release. Selective adrenergic beta-blockers prevent the effects of articular norepinephrine and thereby abrogate vagal control of arthritic joint inflammation. These results reveals a novel neuro-immune brain map with afferent vagal signals controlling side-specific articular inflammation through specific inflammatory-processing brain centers and joint sympathetic innervations. Copyright © 2017 Elsevier Inc. All rights reserved.

The Relationship between a New Biomarker of Vagal Neuroimmunomodulation and Survival in Two Fatal Cancers

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Y. Gidron

2018-01-01

Full Text Available Background. The vagus nerve may slow tumor progression because it inhibits inflammation. This study examined the relationship between a new vagal neuroimmunomodulation (NIM index and survival in fatal cancers. Method. We retroactively derived markers of vagal nerve activity indexed by heart rate variability (HRV, specifically the root mean square of successive differences (RMSSD, from patients’ electrocardiograms near diagnosis. The NIM index was the ratio of RMSSD to C-reactive protein levels (RMSSD/CRP. Sample 1 included 202 Belgian patients with advanced pancreatic cancer (PC, while sample 2 included 71 Belgian patients with non-small cell lung cancer (NSCLC. In both samples, we examined the overall survival, while in sample 2, we additionally examined the survival time in deceased patients. Results. In PC patients, in a multivariate Cox regression controlling for confounders, the NIM index had a protective relative risk (RR of 0.68 and 95% confidence interval (95% CI of 0.51–0.92. In NSCLC patients, the NIM index also had a protective RR of 0.53 and 95% CI of 0.32–0.88. Finally, in NSCLC, patients with a higher NIM index survived more days (475.2 than those with lower NIM (285.1 (p<0.05. Conclusions. The NIM index, reflecting vagal modulation of inflammation, may be a new independent prognostic biomarker in fatal cancers.

Inhibition of reflex vagal bradycardia by a central action of 5-hydroxytryptophan.

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Tadepalli, A. S.

1980-01-01

1 Vagally mediated reflex bradycardia was elicited in spinal cats with intravenous pressor doses of noradrenaline. Administration of 5-hydroxytryptophan (1.5 and 3 mg total dose) into the fourth cerebral ventricle reduced the reflex bradycardia. 2 Inhibition of central amino acid decarboxylase with R044602 prevented the effects of 5-hydroxytryptophan. After intravenous administration of 5-hydroxytryptophan, vagal reflex bradycardia was not affected. 3 Results suggest that 5-hydroxytryptophan ...

Effects of HRV-Guided vs. Predetermined Block Training on Performance, HRV and Serum Hormones.

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Nuuttila, Olli-Pekka; Nikander, Aku; Polomoshnov, Dmitry; Laukkanen, Jari Antero; Häkkinen, Keijo

2017-11-01

The aim of this study was to compare heart rate variability -guided (HRVG) and predetermined (PD) block periodization of high intensity aerobic training (HIT). Endurance performance, neuromuscular performance, heart rate variability (HRV) and serum hormone concentrations were measured before, in the middle and after the 8-week training period in 24 endurance trained males. Both groups improved significantly maximal treadmill velocity (V max ) (pHRV (RMSSD, LF and TP) increased significantly only in HRVG (pHRV and serum testosterone levels observed in HRVG, individually HRV -guided block training may be more optimal compared to predetermined training. © Georg Thieme Verlag KG Stuttgart · New York.

Low vagally-mediated heart rate variability and increased susceptibility to ventricular arrhythmias in rats bred for high anxiety.

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Carnevali, Luca; Trombini, Mimosa; Graiani, Gallia; Madeddu, Denise; Quaini, Federico; Landgraf, Rainer; Neumann, Inga D; Nalivaiko, Eugene; Sgoifo, Andrea

2014-04-10

In humans, there is a documented association between anxiety disorders and cardiovascular disease. Putative underlying mechanisms may include an impairment of the autonomic nervous system control of cardiac function. The primary objective of the present study was to characterize cardiac autonomic modulation and susceptibility to arrhythmias in genetic lines of rats that differ largely in their anxiety level. To reach this goal, electrocardiographic recordings were performed in high-anxiety behavior (HAB, n=10) and low-anxiety behavior (LAB, n=10) rats at rest, during stressful stimuli and under autonomic pharmacological manipulations, and analyzed by means of time- and frequency-domain indexes of heart rate variability. During resting conditions, HAB rats displayed a reduced heart rate variability, mostly in terms of lower parasympathetic (vagal) modulation compared to LAB rats. In HAB rats, this relatively low cardiac vagal control was associated with smaller heart rate responsiveness to acute stressors compared to LAB counterparts. In addition, beta-adrenergic pharmacological stimulation induced a larger incidence of ventricular tachyarrhythmias in HABs compared to LABs. At sacrifice, a moderate increase in heart-body weight ratio was observed in HAB rats. We conclude that high levels of anxiety-related behavior in rats are associated with signs of i) impaired autonomic modulation of heart rate (low vagally-mediated heart rate variability), ii) poor adaptive heart rate responsiveness to stressful stimuli, iii) increased arrhythmia susceptibility, and iv) cardiac hypertrophy. These results highlight the utility of the HAB/LAB model for investigating the mechanistic basis of the comorbidity between anxiety disorders and cardiovascular disease. Copyright © 2014 Elsevier Inc. All rights reserved.

Glucose-dependent trafficking of 5-HT3 receptors in rat gastrointestinal vagal afferent neurons

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Babic, Tanja; Troy, Amanda E; Fortna, Samuel R; Browning, Kirsteen N

2012-01-01

Background Intestinal glucose induces gastric relaxation via vagally mediated sensory-motor reflexes. Glucose can alter the activity of gastrointestinal (GI) vagal afferent (sensory) neurons directly, via closure of ATP-sensitive potassium channels, as well as indirectly, via the release of 5-hydroxytryptamine (5-HT) from mucosal enteroendocrine cells. We hypothesized that glucose may also be able to modulate the ability of GI vagal afferent neurons to respond to the released 5-HT, via regulation of neuronal 5-HT3 receptors. Methods Whole cell patch clamp recordings were made from acutely dissociated GI-projecting vagal afferent neurons exposed to equiosmolar Krebs’ solution containing different concentrations of D-glucose (1.25–20mM) and the response to picospritz application of 5-HT assessed. The distribution of 5-HT3 receptors in neurons exposed to different glucose concentrations was also assessed immunohistochemically. Key Results Increasing or decreasing extracellular D-glucose concentration increased or decreased, respectively, the 5-HT-induced inward current as well as the proportion of 5-HT3 receptors associated with the neuronal membrane. These responses were blocked by the Golgi-disrupting agent Brefeldin-A (5µM) suggesting involvement of a protein trafficking pathway. Furthermore, L-glucose did not mimic the response of D-glucose implying that metabolic events downstream of neuronal glucose uptake are required in order to observe the modulation of 5-HT3 receptor mediated responses. Conclusions & Inferences These results suggest that, in addition to inducing the release of 5-HT from enterochromaffin cells, glucose may also increase the ability of GI vagal sensory neurons to respond to the released 5-HT, providing a means by which the vagal afferent signal can be amplified or prolonged. PMID:22845622

Reduced heart rate variability and vagal tone in anxiety: trait versus state, and the effects of autogenic training.

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Miu, Andrei C; Heilman, Renata M; Miclea, Mircea

2009-01-28

This study investigated heart rate variability (HRV) in healthy volunteers that were selected for extreme scores of trait anxiety (TA), during two opposite psychophysiological conditions of mental stress, and relaxation induced by autogenic training. R-R intervals, HF and LF powers, and LF/HF ratios were derived from short-term electrocardiographic recordings made during mental stress and relaxation by autogenic training, with respiratory rate and skin conductance being controlled for in all the analyses. The main finding was that high TA was associated with reduced R-R intervals and HF power across conditions. In comparison to mental stress, autogenic training increased HRV and facilitated the vagal control of the heart. There were no significant effects of TA or the psychophysiological conditions on LF power, or LF/HF ratio. These results support the view that TA, which is an important risk factor for anxiety disorders and predictor of cardiovascular morbidity and mortality, is associated with autonomic dysfunction that seems likely to play a pathogenetic role in the long term.

Differential Activation of Medullary Vagal Nuclei Caused by Stimulation of Different Esophageal Mechanoreceptors

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Lang, Ivan M.; Medda, Bidyut K.; Shaker, Reza

2010-01-01

Esophageal mechanorecptors, i.e. muscular slowly adapting tension receptors and mucosal rapidly adapting touch receptors, mediate different sets of reflexes. The aim of this study was to determine the medullary vagal nuclei involved in the reflex responses to activation of these receptors. Thirty-three cats were anesthetized with alpha-chloralose and the esophagus was stimulated by slow balloon or rapid air distension. The physiological effects of the stimuli (N=4) were identified by recording responses from the pharyngeal, laryngeal, and hyoid muscles, esophagus, and the lower esophageal sphincter (LES). The effects on the medullary vagal nuclei of the stimuli: slow distension (N=10), rapid distension (N=9), and in control animals (N=10) were identified using the immunohistochemical analysis of c-fos. The experimental groups were stimulated 3 times per minute for 3 hours. After the experiment, the brains were removed and processed for c-fos immunoreactivity or thioinin. We found that slow balloon distension activated the esophago-UES contractile reflex and esophago LES relaxation response, and rapid air injection activated the belch and its component reflexes. Slow balloon distension activated the NTSce, NTSdl, NTSvl, DMNc, DMNr and NAr; and rapid air injection primarily activated AP, NTScd, NTSim, NTSis, NTSdm, NTSvl, NAc and NAr. We concluded that different sets of medullary vagal nuclei mediate different reflexes of the esophagus activated from different sets of mechanoreceptors. The NTScd is the primary NTS subnucleus mediating reflexes from the mucosal rapidly adapting touch receptors, and the NTSce is the primary NTS subnucleus mediating reflexes from the muscular slowly adapting tension receptors. The AP may be involved in mediation of belching. PMID:20971087

Withdrawal and restoration of central vagal afferents within the dorsal vagal complex following subdiaphragmatic vagotomy.

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Peters, James H; Gallaher, Zachary R; Ryu, Vitaly; Czaja, Krzysztof

2013-10-15

Vagotomy, a severing of the peripheral axons of the vagus nerve, has been extensively utilized to determine the role of vagal afferents in viscerosensory signaling. Vagotomy is also an unavoidable component of some bariatric surgeries. Although it is known that peripheral axons of the vagus nerve degenerate and then regenerate to a limited extent following vagotomy, very little is known about the response of central vagal afferents in the dorsal vagal complex to this type of damage. We tested the hypothesis that vagotomy results in the transient withdrawal of central vagal afferent terminals from their primary central target, the nucleus of the solitary tract (NTS). Sprague-Dawley rats underwent bilateral subdiaphragmatic vagotomy and were sacrificed 10, 30, or 60 days later. Plastic changes in vagal afferent fibers and synapses were investigated at the morphological and functional levels by using a combination of an anterograde tracer, synapse-specific markers, and patch-clamp electrophysiology in horizontal brain sections. Morphological data revealed that numbers of vagal afferent fibers and synapses in the NTS were significantly reduced 10 days following vagotomy and were restored to control levels by 30 days and 60 days, respectively. Electrophysiology revealed transient decreases in spontaneous glutamate release, glutamate release probability, and the number of primary afferent inputs. Our results demonstrate that subdiaphragmatic vagotomy triggers transient withdrawal and remodeling of central vagal afferent terminals in the NTS. The observed vagotomy-induced plasticity within this key feeding center of the brain may be partially responsible for the response of bariatric patients following gastric bypass surgery. Copyright © 2013 Wiley Periodicals, Inc.

Reduced self-regulation mirrors the distorting effects of burnout symptomatology on task difficulty perception during an inhibition task.

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Wekenborg, Magdalena Katharina; Hill, LaBarron K; Miller, Robert; Stalder, Tobias; Thayer, Julian Francis; Sophie Penz, Marlene; Kirschbaum, Clemens

2018-06-09

Burnout, a pathological consequence of chronic work stress, shows an increasing incidence rate in industrialized countries. Previous findings indicate that burnout may be linked to a detachment of the negative association between subjectively appraised task demand and cognitive performance, which is typically seen in healthy individuals. The present study sought to confirm this relationship and to investigate whether this dissociation is mirrored in a biological marker of self-regulation, i.e., resting vagally mediated heart rate variability (HRV). A heterogeneous sample (N = 65) of working adults (M age = 43.3, SD = 10; 23.1 % male) with varying degrees of burnout symptomatology completed three cognitive tasks (2-back, number-letter, and go/nogo) to assess different domains of executive functioning (updating, set-shifting, and inhibition), and respective demand ratings. Additionally, vagally mediated HRV at rest, operationalized as the root-mean square differences of successive R-R intervals (RMSSD), was recorded. Burnout symptomatology moderated the association between subjective task difficulty and performance parameters of the go/nogo task, such that higher burnout scores were associated with reductions in the naturally occurring negative association between self-rated task demand and response inhibition. Intriguingly, this pattern was mirrored when replacing burnout with HRV. These findings suggest that burnout symptomatology, and individual differences in self-regulatory capacities (indexed by resting HRV), may alter one's capacity for accurate task evaluation, a mechanism which could potentially underlie the dissociation between self-rated cognitive function and actual performance among individuals experiencing burnout.

Dopamine Mediates the Vagal Modulation of the Immune System by Electroacupuncture

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Torres-Rosas, Rafael; Yehia, Ghassan; Peña, Geber; Mishra, Priya; del Rocio Thompson-Bonilla, Maria; Moreno-Eutimio, Mario Adán; Arriaga-Pizano, Lourdes Andrea; Isibasi, Armando; Ulloa, Luis

2014-01-01

Previous anti-inflammatory strategies against sepsis, a leading cause of death in hospitals, had limited efficacy in clinical trials, in part because they targeted single cytokines and the experimental models failed to mimic clinical settings1-3. Neuronal networks represent physiological mechanisms selected by evolution to control inflammation that can be exploited for the treatment of inflammatory and infectious disorders3. Here, we report that sciatic nerve activation with electroacupuncture controls systemic inflammation and rescues mice from polymicrobial peritonitis. Electroacupuncture at the sciatic nerve controls systemic inflammation by inducing a vagal activation of DOPA decarboxylase leading to the production of dopamine in the adrenal medulla. Experimental models with adrenolectomized animals mimic clinical adrenal insufficiency4, increase the susceptibility to sepsis, and prevent the anti-inflammatory potential of electroacupuncture. Dopamine inhibits cytokine production via dopaminergic type-1 receptors. Dopaminergic D1-agonists suppress systemic inflammation and rescue mice from polymicrobial peritonitis in animals with adrenal insufficiency. Our results suggest a novel anti-inflammatory mechanism mediated by the sciatic and the vagus nerves modulating the production of catecholamines in the adrenal glands. From a pharmacological perspective, selective dopaminergic agonists mimic the anti-inflammatory potential of electroacupuncture and can provide therapeutic advantages to control inflammation in infectious and inflammatory disorders. PMID:24562381

Inter-individual Differences in Heart Rate Variability Are Associated with Inter-individual Differences in Empathy and Alexithymia

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Alexander Lischke

2018-02-01

Full Text Available In the present study, we investigated whether inter-individual differences in vagally mediated heart rate variability (vmHRV would be associated with inter-individual differences in empathy and alexithymia. To this end, we determined resting state HF-HRV in 90 individuals that also completed questionnaires assessing inter-individual differences in empathy and alexithymia. Our categorical and dimensional analyses revealed that inter-individual differences in HF-HRV were differently associated with inter-individual differences in empathy and alexithymia. We found that individuals with high HF-HRV reported more empathy and less alexithymia than individuals with low HF-HRV. Moreover, we even found that an increase in HF-HRV was associated with an increase in empathy and a decrease in alexithymia across all participants. Taken together, these findings indicate that individuals with high HF-HRV are more empathetic and less alexithymic than individuals with low HF-HRV. These differences in empathy and alexithymia may explain why individuals with high HF-HRV are more successful in sharing and understanding the mental and emotional states of others than individuals with low HF-HRV.

A Lunchtime Walk in Nature Enhances Restoration of Autonomic Control during Night-Time Sleep: Results from a Preliminary Study.

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Gladwell, Valerie F; Kuoppa, Pekka; Tarvainen, Mika P; Rogerson, Mike

2016-03-03

Walking within nature (Green Exercise) has been shown to immediately enhance mental well-being but less is known about the impact on physiology and longer lasting effects. Heart rate variability (HRV) gives an indication of autonomic control of the heart, in particular vagal activity, with reduced HRV identified as a risk factor for cardiovascular disease. Night-time HRV allows vagal activity to be assessed whilst minimizing confounding influences of physical and mental activity. The aim of this study was to investigate whether a lunchtime walk in nature increases night-time HRV. Participants (n = 13) attended on two occasions to walk a 1.8 km route through a built or a natural environment. Pace was similar between the two walks. HRV was measured during sleep using a RR interval sensor (eMotion sensor) and was assessed at 1-2 h after participants noted that they had fallen asleep. Markers for vagal activity were significantly greater after the walk in nature compared to the built walk. Lunchtime walks in nature-based environments may provide a greater restorative effect as shown by vagal activity than equivalent built walks. Nature walks may improve essential recovery during night-time sleep, potentially enhancing physiological health.

Vagal afferents modulate cytokine-mediated respiratory control at the neonatal medulla oblongata.

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Balan, Kannan V; Kc, Prabha; Hoxha, Zana; Mayer, Catherine A; Wilson, Christopher G; Martin, Richard J

2011-09-30

Perinatal sepsis and inflammation trigger lung and brain injury in preterm infants, and associated apnea of prematurity. We hypothesized that endotoxin exposure in the immature lung would upregulate proinflammatory cytokine mRNA expression in the medulla oblongata and be associated with impaired respiratory control. Lipopolysaccharide (LPS, 0.1mg/kg) or saline was administered intratracheally to rat pups and medulla oblongatas were harvested for quantifying expression of mRNA for proinflammatory cytokines. LPS-exposure significantly increased medullary mRNA for IL-1β and IL-6, and vagotomy blunted this increase in IL-1β, but not IL-6. Whole-body flow plethysmography revealed that LPS-exposed pups had an attenuated ventilatory response to hypoxia both before and after carotid sinus nerve transection. Immunochemical expression of IL-1β within the nucleus of the solitary tract and area postrema was increased after LPS-exposure. In summary, intratracheal endotoxin-exposure in rat pups is associated with upregulation of proinflammatory cytokines in the medulla oblongata that is vagally mediated for IL-1β and associated with an impaired hypoxic ventilatory response. Copyright © 2011 Elsevier B.V. All rights reserved.

Effect of spontaneous saliva swallowing on short-term heart rate variability (HRV) and reliability of HRV analysis.

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Yildiz, Metin; Doma, Serian

2017-09-26

The effects of effortful swallowing and solid meal ingestions on heart rate variability (HRV) have been examined previously. The effects of spontaneous saliva swallowing on short-term HRV and reliability of HRV analysis have not been studied before. The effect of saliva swallowing on HRV analyses parameters [meanRRI, SDNN (standard deviation of normal-to-normal), LF (low frequency), HF (high frequency) powers, LH/HF] and the reliability of LF and HF powers were investigated by frequency, time-frequency and intraclass correlation coefficient (ICC) analyses. Electrocardiogram and swallowing signal that obtained from an electronic stethoscope placed on the necks of subjects were recorded simultaneously from 30 healthy and young volunteers in sitting position during 15 min. Spontaneous swallowing has been shown to significantly alter some HRV parameters (SDNN, LF power and LF/HF ratio). Time-frequency analysis results showed that the contribution of saliva swallowing to LF (1-58%) and HF (2-42%) powers could change significantly depending on the number of swallowing. The ICC of the LF and HF powers for the successive 5-min signal segments were found 0·89, 0·92, respectively. These values decreased to 0·73 and 0·90 in the subjects with more swallowing rate. When the analyses were made for 2-min signal periods, these values decreased to 0·63 and 0·67. We concluded that spontaneous saliva swallowing can change HRV parameters. We have also seen that changes in swallowing rate and use of short signal segments may reduce the reliability of HRV analyses. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Sluggish vagal brake reactivity to physical exercise challenge in children with selective mutism.

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Heilman, Keri J; Connolly, Sucheta D; Padilla, Wendy O; Wrzosek, Marika I; Graczyk, Patricia A; Porges, Stephen W

2012-02-01

Cardiovascular response patterns to laboratory-based social and physical exercise challenges were evaluated in 69 children and adolescents, 20 with selective mutism (SM), to identify possible neurophysiological mechanisms that may mediate the behavioral features of SM. Results suggest that SM is associated with a dampened response of the vagal brake to physical exercise that is manifested as reduced reactivity in heart rate and respiration. Polyvagal theory proposes that the regulation of the vagal brake is a neurophysiological component of an integrated social engagement system that includes the neural regulation of the laryngeal and pharyngeal muscles. Within this theoretical framework, sluggish vagal brake reactivity may parallel an inability to recruit efficiently the structures involved in speech. Thus, the findings suggest that dampened autonomic reactivity during mobilization behaviors may be a biomarker of SM that can be assessed independent of the social stimuli that elicit mutism.

Vagal gustatory reflex circuits for intraoral food sorting behavior in the goldfish: cellular organization and neurotransmitters.

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Ikenaga, Takanori; Ogura, Tatsuya; Finger, Thomas E

2009-09-20

The sense of taste is crucial in an animal's determination as to what is edible and what is not. This gustatory function is especially important in goldfish, who utilize a sophisticated oropharyngeal sorting mechanism to separate food from substrate material. The computational aspects of this detection are carried out by the medullary vagal lobe, which is a large, laminated structure combining elements of both the gustatory nucleus of the solitary tract and the nucleus ambiguus. The sensory layers of the vagal lobe are coupled to the motor layers via a simple reflex arc. Details of this reflex circuit were investigated with histology and calcium imaging. Biocytin injections into the motor layer labeled vagal reflex interneurons that have radially directed dendrites ramifying within the layers of primary afferent terminals. Axons of reflex interneurons extend radially inward to terminate onto both vagal motoneurons and small, GABAergic interneurons in the motor layer. Functional imaging shows increases in intracellular Ca++ of vagal motoneurons following electrical stimulation in the sensory layer. These responses were suppressed under Ca(++)-free conditions and by interruption of the axons bridging between the sensory and motor layers. Pharmacological experiments showed that glutamate acting via (+/-)-alpha-amino-3-hydroxy- 5-ethylisoxazole-4-propioinc acid (AMPA)/kainate and N-methyl-D-aspartic acid (NMDA) receptors mediate neurotransmission between reflex interneurons and vagal motoneurons. Thus, the vagal gustatory portion of the viscerosensory complex is linked to branchiomotor neurons of the pharynx via a glutamatergic interneuronal system.

Vagal gustatory reflex circuits for intraoral food sorting behavior in the goldfish Cellular organization and neurotransmitters

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Ikenaga, Takanori; Ogura, Tatsuya; Finger, Thomas E.

2009-01-01

The sense of taste is crucial in an animal’s determination as to what is edible and what is not. This gustatory function is especially important in goldfish who utilize a sophisticated oropharyngeal sorting mechanism to separate food from substrate material. The computational aspects of this detection are carried out by the medullary vagal lobe which is a large, laminated structure combining elements of both the gustatory nucleus of the solitary tract and the nucleus ambiguus. The sensory layers of the vagal lobe are coupled to the motor layers via a simple reflex arc. Details of this reflex circuit were investigated with histology and calcium imaging. Biocytin injections into the motor layer labeled vagal reflex interneurons which have radially-directed dendrites ramifying within the layers of primary afferent terminals. Axons of reflex interneurons extend radially inward to terminate onto both vagal motoneurons and small, GABAergic interneurons in the motor layer. Functional imaging shows increases in intracellular Ca++ of vagal motoneurons following electrical stimulation in the sensory layer. These responses were suppressed under Ca++-free conditions and by interruption of the axons bridging between the sensory and motor layers. Pharmacological experiments showed that glutamate acting via (±)-α-amino-3-hydroxy-5-ethylisoxazole-4-propioinc acid (AMPA)/kainate and N-methyl-D-aspartic acid (NMDA) receptors mediates neurotransmission between reflex interneurons and vagal motoneurons. Thus the vagal gustatory portion of the viscerosensory complex is linked to branchiomotor neurons of the pharynx via a glutamatergic interneuronal system. PMID:19598285

Vagal tone during infant contingency learning and its disruption.

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Sullivan, Margaret Wolan

2016-04-01

This study used contingency learning to examine changes in infants' vagal tone during learning and its disruption. The heart rate of 160 five-month-old infants was recorded continuously during the first of two training sessions as they experienced an audiovisual event contingent on their pulling. Maternal reports of infant temperament were also collected. Baseline vagal tone, a measure of parasympathetic regulation of the heart, was related to vagal levels during the infants' contingency learning session, but not to their learner status. Vagal tone levels did not vary significantly over session minutes. Instead, vagal tone levels were a function of both individual differences in learner status and infant soothability. Vagal levels of infants who learned in the initial session were similar regardless of their soothability; however, vagal levels of infants who learned in a subsequent session differed as a function of soothability. Additionally, vagal levels during contingency disruption were significantly higher among infants in this group who were more soothable as opposed to those who were less soothable. The results suggest that contingency learning and disruption is associated with stable vagal tone in the majority of infants, but that individual differences in attention processes and state associated with vagal tone may be most readily observed during the disruption phase. © 2015 Wiley Periodicals, Inc.

Evidence for a vagal pathophysiology for bulimia nervosa and the accompanying depressive symptoms.

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Faris, Patricia L; Eckert, Elke D; Kim, Suck-Won; Meller, William H; Pardo, Jose V; Goodale, Robert L; Hartman, Boyd K

2006-05-01

fluctuations in pain thresholds. Depressive symptoms in these subjects also were reduced by ONDAN. Like pain thresholds, depressive symptoms varied dynamically with the bulimic behaviors, with BDI scores increasing (more depressed) as more time elapsed since the last bulimic episode. PET studies indicated that mechanical distention of the stomach with a balloon (a non-nutritive stimulus) was associated with the activation of several brain loci, including those associated with vagal activation (parabrachial nucleus), emotive aspects of eating (lateral inferior frontal and orbitofrontal), and depressive symptoms (anterior cingulate). The results of the ONDAN study in bulimia nervosa subjects suggest that cyclic increases in vagal activity drive the urge to binge-eat and vomit. The alterations in vagal firing patterns are possibly a physiological adaptation to the high levels of vagal stimulation initially provided by voluntarily binge-eating and vomiting for weight control. The depressive symptoms that occur in association with the urge to binge-eat are also likely due to the cyclic increase in vagal activity. This suggestion is supported by the reduction of depressive symptoms during ONDAN treatment in bulimia subjects and PET imaging studies in normal eating subjects showing that brain loci classically involved in depression are activated by vagal stimulation administered by mechanical gastric distention. In normal eating individuals, depressions accompanying visceral diseases may also be vagally mediated. Ondansetron and other drugs known to modulate vagal activity may be helpful in treating depressions of this origin.

Vagal stimulation in heart failure.

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De Ferrari, Gaetano M

2014-04-01

Heart failure (HF) is accompanied by an autonomic imbalance that is almost always characterized by both increased sympathetic activity and withdrawal of vagal activity. Experimentally, vagal stimulation has been shown to exert profound antiarrhythmic activity and to improve cardiac function and survival in HF models. A open-label pilot clinical study in 32 patients with chronic HF has shown safety and tolerability of chronic vagal stimulation associated with subjective (improved quality of life and 6-min walk test) and objective improvements (reduced left ventricular systolic volumes and improved left ventricular ejection fraction). Three larger clinical studies, including a phase III trial are currently ongoing and will evaluate the clinical role of this new approach.

TRPV1 Channels and Gastric Vagal Afferent Signalling in Lean and High Fat Diet Induced Obese Mice.

Directory of Open Access Journals (Sweden)

Stephen J Kentish

Full Text Available Within the gastrointestinal tract vagal afferents play a role in control of food intake and satiety signalling. Activation of mechanosensitive gastric vagal afferents induces satiety. However, gastric vagal afferent responses to mechanical stretch are reduced in high fat diet mice. Transient receptor potential vanilloid 1 channels (TRPV1 are expressed in vagal afferents and knockout of TRPV1 reduces gastro-oesophageal vagal afferent responses to stretch. We aimed to determine the role of TRPV1 on gastric vagal afferent mechanosensitivity and food intake in lean and HFD-induced obese mice.TRPV1+/+ and -/- mice were fed either a standard laboratory diet or high fat diet for 20wks. Gastric emptying of a solid meal and gastric vagal afferent mechanosensitivity was determined.Gastric emptying was delayed in high fat diet mice but there was no difference between TRPV1+/+ and -/- mice on either diet. TRPV1 mRNA expression in whole nodose ganglia of TRPV1+/+ mice was similar in both dietary groups. The TRPV1 agonist N-oleoyldopamine potentiated the response of tension receptors in standard laboratory diet but not high fat diet mice. Food intake was greater in the standard laboratory diet TRPV1-/- compared to TRPV1+/+ mice. This was associated with reduced response of tension receptors to stretch in standard laboratory diet TRPV1-/- mice. Tension receptor responses to stretch were decreased in high fat diet compared to standard laboratory diet TRPV1+/+ mice; an effect not observed in TRPV1-/- mice. Disruption of TRPV1 had no effect on the response of mucosal receptors to mucosal stroking in mice on either diet.TRPV1 channels selectively modulate gastric vagal afferent tension receptor mechanosensitivity and may mediate the reduction in gastric vagal afferent mechanosensitivity in high fat diet-induced obesity.

Acupuncture analgesia involves modulation of pain-induced gamma oscillations and cortical network connectivity.

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Hauck, Michael; Schröder, Sven; Meyer-Hamme, Gesa; Lorenz, Jürgen; Friedrichs, Sunja; Nolte, Guido; Gerloff, Christian; Engel, Andreas K

2017-11-24

Recent studies support the view that cortical sensory, limbic and executive networks and the autonomic nervous system might interact in distinct manners under the influence of acupuncture to modulate pain. We performed a double-blind crossover design study to investigate subjective ratings, EEG and ECG following experimental laser pain under the influence of sham and verum acupuncture in 26 healthy volunteers. We analyzed neuronal oscillations and inter-regional coherence in the gamma band of 128-channel-EEG recordings as well as heart rate variability (HRV) on two experimental days. Pain ratings and pain-induced gamma oscillations together with vagally-mediated power in the high-frequency bandwidth (vmHF) of HRV decreased significantly stronger during verum than sham acupuncture. Gamma oscillations were localized in the prefrontal cortex (PFC), mid-cingulate cortex (MCC), primary somatosensory cortex and insula. Reductions of pain ratings and vmHF-power were significantly correlated with increase of connectivity between the insula and MCC. In contrast, connectivity between left and right PFC and between PFC and insula correlated positively with vmHF-power without a relationship to acupuncture analgesia. Overall, these findings highlight the influence of the insula in integrating activity in limbic-saliency networks with vagally mediated homeostatic control to mediate antinociception under the influence of acupuncture.

Exercise effects on HRV in cancer patients.

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Niederer, D; Vogt, L; Thiel, C; Schmidt, K; Bernhörster, M; Lungwitz, A; Jäger, E; Banzer, W

2013-01-01

The present study evaluated the effects of physical exercise on heart rate variability (HRV) in cancer patients. 3 matched groups of each 15 tumour patients (60.4±8.9 years, 27 male, 18 female) were recruited: Physical exercise group 1 (acute treatment), Physical exercise group 2 (post treatment) and non-intervention group (acute treatment, no exercise). Exercise group patients received counselling for exercise and participated in a Nordic-Walking program. Short-term HRV-recordings, assessments of fatigue and quality of life (QoL) were performed prior to and 16 weeks after the exercise program initiation. MANCOVA revealed group × time differences in total power frequency domain of HRV and QoL (pHRV-parameters and prolonged survival in cancer patients, improvement in autonomic control may be an important goal of exercise. © Georg Thieme Verlag KG Stuttgart · New York.

Characterization of structural proteins of hirame rhabdovirus, HRV

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Nishizawa, Toyohiko; Yoshimizu, Mamoru; Winton, James; Ahne, Winfried; Kimura, Takahisa

1991-01-01

Structural proteins of hirame rhabdovirus (HRV) were analyzed by SDS-polyacrylarnide gel electrophoresis, western blotting, 2-dimensional gel electrophoresis, and Triton X-100 treatment. Purified HRV virions were composed of: polymerase (L), glycoprotein (G), nucleoprotein (N), and 2 matrix proteins (M1 and M2). Based upon their relative mobilities, the estimated molecular weights of the proteins were: L, 156 KDa; G, 68 KDa; N, 46.4 KDa; M1, 26.4 KDa; and M2, 19.9 KDa. The electrophorehc pattern formed by the structural proteins of HRV was clearly different from that formed by pike fry rhabdovirus, spring viremia of carp virus, eel virus of America, and eel virus European X which belong to the Vesiculovirus genus; however, it resembled the pattern formed by structural proteins of viral hemorrhagic septicemia virus (VHSV) and infectious hematopoietic necrosis virus (IHNV) which are members of the Lyssavirus genus. Among HRV, IHNV, and VHSV, differences were observed in the relative mobilities of the G, N, M1, and M2 proteins. Western blot analysis revealed that the G. N, and M2 proteins of HRV shared antigenic determinants with IHNV and VHSV, but not with any of the 4 fish vesiculoviruses tested. Cross-reactions between the M1 proteins of HRV, IHNV, or VHSV were not detected in this assay. Two-dimensional gel electrophoresis was used to show that HRV differed from IHNV or VHSV in the isoelectric point (PI) of the M1 and M2 proteins. In this system, 2 forms of the M1 protein of HRV and IHNV were observed.These subspecies of M1 had the same relative mobility but different p1 values. Treatment of purified virions with 2% Triton X-100 in Tris buffer containing NaCl removed the G, M1, and M2 proteins of IHNV, but HRV virions were more stable under these conditions.

Moderate Baseline Vagal Tone Predicts Greater Prosociality in Children

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Miller, Jonas G.; Kahle, Sarah; Hastings, Paul D.

2016-01-01

Vagal tone is widely believed to be an important physiological aspect of emotion regulation and associated positive behaviors. However, there is inconsistent evidence for relations between children’s baseline vagal tone and their helpful or prosocial responses to others (Hastings & Miller, 2014). Recent work in adults suggests a quadratic association (inverted U-shape curve) between baseline vagal tone and prosociality (Kogan et al., 2014). The present research examined whether this nonlinear association was evident in children. We found consistent evidence for a quadratic relation between vagal tone and prosociality across 3 samples of children using 6 different measures. Compared to low and high vagal tone, moderate vagal tone in early childhood concurrently predicted greater self-reported prosociality (Study 1), observed empathic concern in response to the distress of others and greater generosity toward less fortunate peers (Study 2), and longitudinally predicted greater self-, mother-, and teacher-reported prosociality 5.5 years later in middle childhood (Study 3). Taken together, our findings suggest that moderate vagal tone at rest represents a physiological preparedness or tendency to engage in different forms of prosociality across different contexts. Early moderate vagal tone may reflect an optimal balance of regulation and arousal that helps prepare children to sympathize, comfort, and share with others. PMID:27819463

Lipid-rich enteral nutrition regulates mucosal mast cell activation via the vagal anti-inflammatory reflex

NARCIS (Netherlands)

de Haan, Jacco J.; Hadfoune, M.'hamed; Lubbers, Tim; Hodin, Caroline; Lenaerts, Kaatje; Ito, Akihiko; Verbaeys, Isabelle; Skynner, Michael J.; Cailotto, Cathy; van der Vliet, Jan; de Jonge, Wouter J.; Greve, Jan-Willem M.; Buurman, Wim A.

2013-01-01

Nutritional stimulation of the cholecystokinin-1 receptor (CCK-1R) and nicotinic acetylcholine receptor (nAChR)-mediated vagal reflex was shown to reduce inflammation and preserve intestinal integrity. Mast cells are important early effectors of the innate immune response; therefore modulation of

Allostatic load and heart rate variability as health risk indicators.

African Journals Online (AJOL)

investigate the feasibility of inclusion of HRV indicators into allostatic load assessments and which HRV ... said to reflect stressor-induced activation of the two ... reduced in stress and said to be of prognostic value for ... Recruitment by a power point-illustrat- .... values (Total HRV and vagal activity dependent HRV) can.

Evaluation of HRV Biofeedback as a Resilience Building Reserve Component

Science.gov (United States)

2017-08-01

introductory training in either HRV-BART or relaxation breathing alone and be assessed on baseline HRV and mental and physical health questionnaires...receive a 1.5-hour group introductory training in either HRV-BART or relaxation breathing alone and be assessed on baseline HRV and mental and physical...F., Furman, S. A., McCool, M. F., & Porges, S. W. (2012). Statistical strategies to quantify respiratory sinus arrhythmia: Are commonly used metrics

CameraHRV: robust measurement of heart rate variability using a camera

Science.gov (United States)

Pai, Amruta; Veeraraghavan, Ashok; Sabharwal, Ashutosh

2018-02-01

The inter-beat-interval (time period of the cardiac cycle) changes slightly for every heartbeat; this variation is measured as Heart Rate Variability (HRV). HRV is presumed to occur due to interactions between the parasym- pathetic and sympathetic nervous system. Therefore, it is sometimes used as an indicator of the stress level of an individual. HRV also reveals some clinical information about cardiac health. Currently, HRV is accurately measured using contact devices such as a pulse oximeter. However, recent research in the field of non-contact imaging Photoplethysmography (iPPG) has made vital sign measurements using just the video recording of any exposed skin (such as a person's face) possible. The current signal processing methods for extracting HRV using peak detection perform well for contact-based systems but have poor performance for the iPPG signals. The main reason for this poor performance is the fact that current methods are sensitive to large noise sources which are often present in iPPG data. Further, current methods are not robust to motion artifacts that are common in iPPG systems. We developed a new algorithm, CameraHRV, for robustly extracting HRV even in low SNR such as is common with iPPG recordings. CameraHRV combined spatial combination and frequency demodulation to obtain HRV from the instantaneous frequency of the iPPG signal. CameraHRV outperforms other current methods of HRV estimation. Ground truth data was obtained from FDA-approved pulse oximeter for validation purposes. CameraHRV on iPPG data showed an error of 6 milliseconds for low motion and varying skin tone scenarios. The improvement in error was 14%. In case of high motion scenarios like reading, watching and talking, the error was 10 milliseconds.

Comparative Genetic Analyses of Human Rhinovirus C (HRV-C) Complete Genome from Malaysia

Science.gov (United States)

Khaw, Yam Sim; Chan, Yoke Fun; Jafar, Faizatul Lela; Othman, Norlijah; Chee, Hui Yee

2016-01-01

Human rhinovirus-C (HRV-C) has been implicated in more severe illnesses than HRV-A and HRV-B, however, the limited number of HRV-C complete genomes (complete 5′ and 3′ non-coding region and open reading frame sequences) has hindered the in-depth genetic study of this virus. This study aimed to sequence seven complete HRV-C genomes from Malaysia and compare their genetic characteristics with the 18 published HRV-Cs. Seven Malaysian HRV-C complete genomes were obtained with newly redesigned primers. The seven genomes were classified as HRV-C6, C12, C22, C23, C26, C42, and pat16 based on the VP4/VP2 and VP1 pairwise distance threshold classification. Five of the seven Malaysian isolates, namely, 3430-MY-10/C22, 8713-MY-10/C23, 8097-MY-11/C26, 1570-MY-10/C42, and 7383-MY-10/pat16 are the first newly sequenced complete HRV-C genomes. All seven Malaysian isolates genomes displayed nucleotide similarity of 63–81% among themselves and 63–96% with other HRV-Cs. Malaysian HRV-Cs had similar putative immunogenic sites, putative receptor utilization and potential antiviral sites as other HRV-Cs. The genomic features of Malaysian isolates were similar to those of other HRV-Cs. Negative selections were frequently detected in HRV-Cs complete coding sequences indicating that these sequences were under functional constraint. The present study showed that HRV-Cs from Malaysia have diverse genetic sequences but share conserved genomic features with other HRV-Cs. This genetic information could provide further aid in the understanding of HRV-C infection. PMID:27199901

gHRV: Heart rate variability analysis made easy.

Science.gov (United States)

Rodríguez-Liñares, L; Lado, M J; Vila, X A; Méndez, A J; Cuesta, P

2014-08-01

In this paper, the gHRV software tool is presented. It is a simple, free and portable tool developed in python for analysing heart rate variability. It includes a graphical user interface and it can import files in multiple formats, analyse time intervals in the signal, test statistical significance and export the results. This paper also contains, as an example of use, a clinical analysis performed with the gHRV tool, namely to determine whether the heart rate variability indexes change across different stages of sleep. Results from tests completed by researchers who have tried gHRV are also explained: in general the application was positively valued and results reflect a high level of satisfaction. gHRV is in continuous development and new versions will include suggestions made by testers. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

EFFECT OF SPIRONOLACTONE ON HEART RATE VARIABILITY (HRV IN DIABETIC PATIENTS

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Ramin Heydari

2010-12-01

Full Text Available Abstract  INTRODUCTION: Diabetes mellitus is the most common metabolic and endocrine disease. Depressed Heart Rate Variability (HRV is an early warning sign of diabetic neuropathy. In numerous studies, spironolactone improved HRV and decreased mortality in Congestive Heart Failure (CHF. This study was performed to assess the effect of spironolactone on HRV in diabetic patients. methods: This prospective, randomized, double-blind clinical trial was performed on 62 diabetic patients with autonomic neuropathy at Isfahan Cardiovascular Research Center. Baseline HRV was measured with time domain and frequency domain methods using a Valiance system manufactured by US Biomedical Systems Inc. (2000. The patients were then randomly placed in case and control groups. The control group was given placebo and the case group was given 25mg spironolactone twice daily for two months. HRV was measured at the end of this period and data were analyzed using SPSS. HRV before and after medication was compared with t-test, paired t-test, Wilcoxon test, and Mann-Whitney test. results: Twenty-nine patients in the control group and thirty-three patients in the case group were assessed. HRV was measured before and after the study. T-test and Mann-Whitney test revealed no significant difference between HRV in the two groups. Paired t-test and Wilcoxon test did not show any significant difference of HRV within the two groups. Discussion: In this study, spironolactone did not improve HRV in diabetic patients. 

Heart and soul: heart rate variability and major depression.

Science.gov (United States)

Kidwell, Meyrick; Ellenbroek, Bart A

2018-04-01

There is a bidirectional relationship between affective disorders and cardiovascular abnormalities, often described as a downward spiral, whereas major depressive disorders (MDD, and anxiety disorders) significantly increase the risk of developing cardiovascular diseases (CVD); CVD are also associated with increased risk of developing MDD (and anxiety disorders). Moreover, the prognosis and progression of CVD is significantly worsened in the presence of MDD. Heart rate variability (HRV) has often been suggested as a potential mediator in this comorbidity. In this review, we discuss HRV alterations in MDD. However, we mainly focus on the direct relationship between HRV alterations and psychiatric symptoms, rather than its relationship with CVD, as this has been reviewed elsewhere. After a general introduction to HRV and how it can be measured, we review how HRV is altered in MDD. We subsequently describe how antidepressant drugs affect HRV, showing that some classes (such as tricyclics) generally worsen HRV, whereas others (most notably selective serotonin reuptake inhibitors) have a more positive influence. We also review the effects of several other treatments, with a special focus on vagal nerve stimulation, finishing with some further considerations and recommendation for further research, both in humans and animals.

Application of HRV-CD for estimation of life expectancy in various clinical disorders.

Science.gov (United States)

Almoznino-Sarafian, Dorit; Sarafian, Gideon; Zyssman, Itzhak; Shteinshnaider, Miriam; Tzur, Irma; Kaplan, Ben-Zion; Berman, Sylvia; Cohen, Natan; Gorelik, Oleg

2009-12-01

Low heart rate variability (HRV) was found in various medical conditions including heart failure and acute myocardial infarction. Decreased HRV in these conditions predicted poor prognosis. HRV was estimated in 133 unselected inpatients with relevant clinical bedside conditions by non-linear analysis derived from chaos theory, which calculates the correlation dimension (CD) of the cardiac electrophysiologic system (HRV-CD). Mean HRV-CD in the entire group was 3.75+/-0.45. Heart failure, coronary artery disease, cardiac arrhythmia, low serum potassium, renal dysfunction, and diabetes mellitus were significantly associated with reduced HRV-CD compared to their counterparts [3.6 vs. 3.9 (P3.75) was associated with lower survival (P=.01). Mortality of diabetic patients with HRV-CD 3.75 (P=.02). Heart failure, renal dysfunction or age over 70 combined with HRV-CD < or =3.75 also appeared to be associated with augmented mortality. Diminished HRV-CD is associated with heart failure, coronary artery disease, cardiac arrhythmia, renal dysfunction, diabetes mellitus and low serum potassium. Among the latter, heart failure is most significantly associated with decreased HRV-CD. Decreased HRV-CD values, especially in diabetics, are also associated with lower survival.

The Effect of Sham Feeding on Neurocardiac Regulation in Healthy Human Volunteers

Directory of Open Access Journals (Sweden)

Markad V Kamath

2007-01-01

Full Text Available BACKGROUND: Distension and electrical stimuli in the esophagus alter heart rate variability (HRV consistent with activation of vagal afferent and efferent pathways. Sham feeding stimulates gastric acid secretion by means of vagal efferent pathways. It is not known, however, whether activation of vagal efferent pathways is organ- or stimulus-specific.

Cholecystokinin enhances visceral pain-related affective memory via vagal afferent pathway in rats

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Cao Bing

2012-06-01

Full Text Available Abstract Background Pain contains both sensory and affective dimensions. Using a rodent visceral pain assay that combines the colorectal distension (CRD model with the conditioned place avoidance (CPA paradigms, we measured a learned behavior that directly reflects the affective component of visceral pain, and showed that perigenual anterior cingulate cortex (pACC activation is critical for memory processing involved in long-term visceral affective state and prediction of aversive stimuli by contextual cue. Progress has been made and suggested that activation of vagal afferents plays a role in the behavioral control nociception and memory storage processes. In human patients, electrical vagus nerve stimulation enhanced retention of verbal learning performance. Cholecystokinin-octapeptide (CCK, which is a gastrointestinal hormone released during feeding, has been shown to enhance memory retention. Mice access to food immediately after training session enhanced memory retention. It has been well demonstrated that CCK acting on vagal afferent fibers mediates various physiological functions. We hypothesize that CCK activation of vagal afferent enhances visceral pain-related affective memory. Results In the presented study, infusion of CCK-8 at physiological concentration combining with conditional training significantly increased the CRD-induced CPA scores, and enhanced the pain affective memory retention. In contrast, CCK had no effect on CPA induced by non-nociceptive aversive stimulus (U69,593. The physiological implications were further strengthened by the similar effects observed in the rats with duodenal infusion of 5% peptone, which has been shown to induce increases in plasma CCK levels. CCK-8 receptor antagonist CR-1409 or perivagal application of capsaicin abolished the effect of CCK on aversive visceral pain memory, which was consistent with the notion that vagal afferent modulates affective aspects of visceral pain. CCK does not change

Cholecystokinin enhances visceral pain-related affective memory via vagal afferent pathway in rats.

Science.gov (United States)

Cao, Bing; Zhang, Xu; Yan, Ni; Chen, Shengliang; Li, Ying

2012-06-09

Pain contains both sensory and affective dimensions. Using a rodent visceral pain assay that combines the colorectal distension (CRD) model with the conditioned place avoidance (CPA) paradigms, we measured a learned behavior that directly reflects the affective component of visceral pain, and showed that perigenual anterior cingulate cortex (pACC) activation is critical for memory processing involved in long-term visceral affective state and prediction of aversive stimuli by contextual cue. Progress has been made and suggested that activation of vagal afferents plays a role in the behavioral control nociception and memory storage processes.In human patients, electrical vagus nerve stimulation enhanced retention of verbal learning performance. Cholecystokinin-octapeptide (CCK), which is a gastrointestinal hormone released during feeding, has been shown to enhance memory retention. Mice access to food immediately after training session enhanced memory retention. It has been well demonstrated that CCK acting on vagal afferent fibers mediates various physiological functions. We hypothesize that CCK activation of vagal afferent enhances visceral pain-related affective memory. In the presented study, infusion of CCK-8 at physiological concentration combining with conditional training significantly increased the CRD-induced CPA scores, and enhanced the pain affective memory retention. In contrast, CCK had no effect on CPA induced by non-nociceptive aversive stimulus (U69,593). The physiological implications were further strengthened by the similar effects observed in the rats with duodenal infusion of 5% peptone, which has been shown to induce increases in plasma CCK levels. CCK-8 receptor antagonist CR-1409 or perivagal application of capsaicin abolished the effect of CCK on aversive visceral pain memory, which was consistent with the notion that vagal afferent modulates affective aspects of visceral pain. CCK does not change the nociceptive response (visceral pain

Vagal nerve stimulation therapy: what is being stimulated?

Science.gov (United States)

Kember, Guy; Ardell, Jeffrey L; Armour, John A; Zamir, Mair

2014-01-01

Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the vagal sympathetic complex as a differential activation of each component in the control of heart rate. The model provides insight beyond what is available in the animal experiment in as much as allowing the simultaneous assessment of neuronal activity throughout the cardiac neural axis. The results indicate that there is sensitivity of the neural network to low level subthreshold stimulation. This leads us to propose that the chronic effects of vagal nerve stimulation therapy lie within the indirect pathways that target intrinsic cardiac local circuit neurons because they have the capacity for plasticity.

Vagal nerve stimulation therapy: what is being stimulated?

Directory of Open Access Journals (Sweden)

Guy Kember

Full Text Available Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the vagal sympathetic complex as a differential activation of each component in the control of heart rate. The model provides insight beyond what is available in the animal experiment in as much as allowing the simultaneous assessment of neuronal activity throughout the cardiac neural axis. The results indicate that there is sensitivity of the neural network to low level subthreshold stimulation. This leads us to propose that the chronic effects of vagal nerve stimulation therapy lie within the indirect pathways that target intrinsic cardiac local circuit neurons because they have the capacity for plasticity.

The use of historical range and variability (HRV) in landscape management

Science.gov (United States)

Robert E. Keane; Paul F. Hessburg; Peter B. Landres; Fred J. Swanson

2009-01-01

This paper examines the past, present, and future use of the concept of historical range and variability (HRV) in land management. The history, central concepts, benefits, and limitations of HRV are presented along with a discussion on the value of HRV in a changing world with rapid climate warming, exotic species invasions, and increased land development. This paper...

Does Physiological Stress Slow Down Wound Healing in Patients With Diabetes?

Science.gov (United States)

Razjouyan, Javad; Grewal, Gurtej Singh; Talal, Talal K; Armstrong, David G; Mills, Joseph L; Najafi, Bijan

2017-07-01

Poor healing is an important contributing factor to amputation among patients with diabetic foot ulcers (DFUs). Physiological stress may slow wound healing and increase susceptibility to infection. The objective was to examine the association between heart rate variability (HRV) as an indicator of physiological stress response and healing speed (Heal Speed ) among outpatients with active DFUs. Ambulatory patients with diabetes with DFUs (n = 25, age: 59.3 ± 8.3 years) were recruited. HRV during pre-wound dressing was measured using a wearable sensor attached to participants' chest. HRVs were quantified in both time and frequency domains to assess physiological stress response and vagal tone (relaxation). Change in wound size between two consecutive visits was used to estimate Heal Speed . Participants were then categorized into slow healing and fast healing groups. Between the two groups, comparisons were performed for demographic, clinical, and HRV derived parameters. Associations between different descriptors of HRV and Heal Speed were also assessed. Heal Speed was significantly correlated with both vagal tone ( r = -.705, P = .001) and stress response ( r = .713, P = .001) extracted from frequency domain. No between-group differences were observed except those from HRV-derived parameters. Models based on HRVs were the highest predictors of slow/fast Heal Speed (AUC > 0.90), while models based on demographic and clinical information had poor classification performance (AUC = 0.44). This study confirms an association between stress/vagal tone and wound healing in patients with DFUs. In particular, it highlights the importance of vagal tone (relaxation) in expediting wound healing. It also demonstrates the feasibility of assessing physiological stress responses using wearable technology in outpatient clinic during routine clinic visits.

Differential Activation of Medullary Vagal Nuclei Caused by Stimulation of Different Esophageal Mechanoreceptors

OpenAIRE

Lang, Ivan M.; Medda, Bidyut K.; Shaker, Reza

2010-01-01

Esophageal mechanorecptors, i.e. muscular slowly adapting tension receptors and mucosal rapidly adapting touch receptors, mediate different sets of reflexes. The aim of this study was to determine the medullary vagal nuclei involved in the reflex responses to activation of these receptors. Thirty-three cats were anesthetized with alpha-chloralose and the esophagus was stimulated by slow balloon or rapid air distension. The physiological effects of the stimuli (N=4) were identified by recordin...

EFFECTS OF VAGAL SENSORY INPUT ON THE BREATHING RHYTHM OF THE CARP

NARCIS (Netherlands)

DEGRAAF, PJF; ROBERTS, BL

Electrical stimulation of an epibranchial vagal ganglion, which innervates the gill region, had a marked influence on the respiratory rhythm of the carp Cyprinus carpio. Vagal input could initiate ventilation in fish displaying intermittent respiration. In fish breathing steadily, vagal stimuli

Heart rate variability (HRV): an indicator of stress

Science.gov (United States)

Kaur, Balvinder; Durek, Joseph J.; O'Kane, Barbara L.; Tran, Nhien; Moses, Sophia; Luthra, Megha; Ikonomidou, Vasiliki N.

2014-05-01

Heart rate variability (HRV) can be an important indicator of several conditions that affect the autonomic nervous system, including traumatic brain injury, post-traumatic stress disorder and peripheral neuropathy [3], [4], [10] & [11]. Recent work has shown that some of the HRV features can potentially be used for distinguishing a subject's normal mental state from a stressed one [4], [13] & [14]. In all of these past works, although processing is done in both frequency and time domains, few classification algorithms have been explored for classifying normal from stressed RRintervals. In this paper we used 30 s intervals from the Electrocardiogram (ECG) time series collected during normal and stressed conditions, produced by means of a modified version of the Trier social stress test, to compute HRV-driven features and subsequently applied a set of classification algorithms to distinguish stressed from normal conditions. To classify RR-intervals, we explored classification algorithms that are commonly used for medical applications, namely 1) logistic regression (LR) [16] and 2) linear discriminant analysis (LDA) [6]. Classification performance for various levels of stress over the entire test was quantified using precision, accuracy, sensitivity and specificity measures. Results from both classifiers were then compared to find an optimal classifier and HRV features for stress detection. This work, performed under an IRB-approved protocol, not only provides a method for developing models and classifiers based on human data, but also provides a foundation for a stress indicator tool based on HRV. Further, these classification tools will not only benefit many civilian applications for detecting stress, but also security and military applications for screening such as: border patrol, stress detection for deception [3],[17], and wounded-warrior triage [12].

Urotensin II promotes vagal-mediated bradycardia by activating cardiac-projecting parasympathetic neurons of nucleus ambiguus.

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Brailoiu, Gabriela Cristina; Deliu, Elena; Rabinowitz, Joseph E; Tilley, Douglas G; Koch, Walter J; Brailoiu, Eugen

2014-05-01

Urotensin II (U-II) is a cyclic undecapeptide that regulates cardiovascular function at central and peripheral sites. The functional role of U-II nucleus ambiguus, a key site controlling cardiac tone, has not been established, despite the identification of U-II and its receptor at this level. We report here that U-II produces an increase in cytosolic Ca(2+) concentration in retrogradely labeled cardiac vagal neurons of nucleus ambiguus via two pathways: (i) Ca(2+) release from the endoplasmic reticulum via inositol 1,4,5-trisphosphate receptor; and (ii) Ca(2+) influx through P/Q-type Ca(2+) channels. In addition, U-II depolarizes cultured cardiac parasympathetic neurons. Microinjection of increasing concentrations of U-II into nucleus ambiguus elicits dose-dependent bradycardia in conscious rats, indicating the in vivo activation of the cholinergic pathway controlling the heart rate. Both the in vitro and in vivo effects were abolished by the urotensin receptor antagonist, urantide. Our findings suggest that, in addition, to the previously reported increase in sympathetic outflow, U-II activates cardiac vagal neurons of nucleus ambiguus, which may contribute to cardioprotection. © 2014 International Society for Neurochemistry.

Stanovení vagového prahu a možnosti jeho využití Determination of the vagal threshold and changes of it's using

Directory of Open Access Journals (Sweden)

Aleš Gába

2008-01-01

Full Text Available Cílem této studie bylo navrhnout jednoduchý matematický postup, podle kterého by bylo možno stanovit takovou hraniční intenzitu zatížení, nad kterou se redukovaná vagová aktivita dále výrazně nemění a kardiovaskulární systém je dominantně řízen zvyšující se aktivitou sympatoadrenálního systému (vagový práh – TVA. Testovaný soubor tvořilo 10 mužů ve věku 27,24 ± 3,23 let s hodnotou maximální spotřeby kyslíku 50,24 ± 4,63 ml.kg–1.min–1. Aktivita ANS byla hodnocena pomocí neinvazivní metody spektrální analýzy (SA variability srdeční frekvence (HRV. Změny v autonomní kardiální regulaci byly posuzovány během chůze na běhátku v setrvalém stavu při intenzitách zatížení od 20 % do 70 % maximální tepové rezervy (MTR. Zvýšení intenzity zatížení o 10 % MTR v rozmezí od 20 % do 70 % MTR vedlo vždy k signifikantnímu snížení aktivity vagu. Navržený postup pro stanovení deflekčního bodu křivky závislosti PHF na intenzitě zatížení, za kterým již PHF výrazně neklesá, umožnil identifikovat TVA na úrovni 43,63 ± 4,66 % MTR. Navržený algoritmus stanovení TVA dovoluje odhadnout při tělesné práci "bezpečnou" intenzitu zatížení, při které je ještě zachována aktivita vagu a aktivita sympatiku se ještě výrazně nezvyšuje. Stanovení TVA se může uplatnit zejména při preskripci intenzity zatížení v rámci programu pohybové aktivity u pacientů s redukovanou aktivitou ANS a se zvýšeným rizikem náhlé srdeční příhody. Exercise intensity causes changes in the activity of both branches of the autonomic nervous system (ANS as involved in cardiovascular system regulation. Reduction in vagal activity and an increase in sympatho-adrenal activity is associated with an increase in death risk from both cardiac and arrhythmic causes during exercise. The main aim of this work was to develop a simple mathematic algorithm for determination of

Vagal afferents contribute to exacerbated airway responses following ozone and allergen challenge.

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Schelegle, Edward S; Walby, William F

2012-05-31

Brown-Norway rats (n=113) sensitized and challenged with nDer f 1 allergen were used to examine the contribution of lung sensory nerves to ozone (O(3)) exacerbation of asthma. Prior to their third challenge rats inhaled 1.0ppm O(3) for 8h. There were three groups: (1) control; (2) vagus perineural capsaicin treatment (PCT) with or without hexamethonium; and (3) vagotomy. O(3) inhalation resulted in a significant increase in lung resistance (R(L)) and an exaggerated response to subsequent allergen challenge. PCT abolished the O(3)-induced increase in R(L) and significantly reduced the increase in R(L) induced by a subsequent allergen challenge, while hexamethonium treatment reestablished bronchoconstriction induced by allergen challenge. Vagotomy resulted in a significant increase in the bronchoconstriction induced by O(3) inhalation and subsequent challenge with allergen. In this model of O(3) exacerbation of asthma, vagal C-fibers initiate reflex bronchoconstriction, vagal myelinated fibers initiate reflex bronchodilation, and mediators released within the airway initiate bronchoconstriction. Copyright © 2012 Elsevier B.V. All rights reserved.

Toward Hypertension Prediction Based on PPG-Derived HRV Signals: a Feasibility Study.

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Lan, Kun-Chan; Raknim, Paweeya; Kao, Wei-Fong; Huang, Jyh-How

2018-04-21

Heart rate variability (HRV) is often used to assess the risk of cardiovascular disease, and data on this can be obtained via electrocardiography (ECG). However, collecting heart rate data via photoplethysmography (PPG) is now a lot easier. We investigate the feasibility of using the PPG-based heart rate to estimate HRV and predict diseases. We obtain three months of PPG-based heart rate data from subjects with and without hypertension, and calculate the HRV based on various forms of time and frequency domain analysis. We then apply a data mining technique to this estimated HRV data, to see if it is possible to correctly identify patients with hypertension. We use six HRV parameters to predict hypertension, and find SDNN has the best predictive power. We show that early disease prediction is possible through collecting one's PPG-based heart rate information.

Monitoring Fatigue Status with HRV Measures in Elite Athletes: An Avenue Beyond RMSSD?

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Schmitt, Laurent; Regnard, Jacques; Millet, Grégoire P.

2015-01-01

Among the tools proposed to assess the athlete's “fatigue,” the analysis of heart rate variability (HRV) provides an indirect evaluation of the settings of autonomic control of heart activity. HRV analysis is performed through assessment of time-domain indices, the square root of the mean of the sum of the squares of differences between adjacent normal R-R intervals (RMSSD) measured during short (5 min) recordings in supine position upon awakening in the morning and particularly the logarithm of RMSSD (LnRMSSD) has been proposed as the most useful resting HRV indicator. However, if RMSSD can help the practitioner to identify a global “fatigue” level, it does not allow discriminating different types of fatigue. Recent results using spectral HRV analysis highlighted firstly that HRV profiles assessed in supine and standing positions are independent and complementary; and secondly that using these postural profiles allows the clustering of distinct sub-categories of “fatigue.” Since, cardiovascular control settings are different in standing and lying posture, using the HRV figures of both postures to cluster fatigue state embeds information on the dynamics of control responses. Such, HRV spectral analysis appears more sensitive and enlightening than time-domain HRV indices. The wealthier information provided by this spectral analysis should improve the monitoring of the adaptive training-recovery process in athletes. PMID:26635629

Vagal modulation of high mobility group box-1 protein mediates electroacupuncture-induced cardioprotection in ischemia-reperfusion injury.

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Zhang, Juan; Yong, Yue; Li, Xing; Hu, Yu; Wang, Jian; Wang, Yong-qiang; Song, Wei; Chen, Wen-ting; Xie, Jian; Chen, Xue-mei; Lv, Xin; Hou, Li-li; Wang, Ke; Zhou, Jia; Wang, Xiang-rui; Song, Jian-gang

2015-10-26

Excessive release of high mobility group box-1 (HMGB1) protein from ischemic cardiomyocytes activates inflammatory cascades and enhances myocardial injury after reperfusion. Here we report evidence that electroacupuncture of mice at Neiguan acupoints can inhibit the up-regulation of cardiac HMGB1 following myocardial ischemia and attenuate the associated inflammatory responses and myocardial injury during reperfusion. These benefits of electroacupuncture were partially reversed by administering recombinant HMGB1 to the mice, and further potentiated by administering anti-HMGB1 antibody. Electroacupuncture-induced inhibition of HMGB1 release was markedly reduced by unilateral vagotomy or administration of nicotinic receptor antagonist, but not by chemical sympathectomy. The cholinesterase inhibitor neostigmine mimicked the effects of electroacupuncture on HMGB1 release and myocardial ischemia reperfusion injury. Culture experiments with isolated neonatal cardiomyocytes showed that acetylcholine, but not noradrenaline, inhibited hypoxia-induced release of HMGB1 via a α7nAchR-dependent pathway. These results suggest that electroacupuncture acts via the vagal nerve and its nicotinic receptor-mediated signaling to inhibit HMGB1 release from ischemic cardiomyocytes. This helps attenuate pro-inflammatory responses and myocardial injury during reperfusion.

Facial Video-Based Photoplethysmography to Detect HRV at Rest.

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Moreno, J; Ramos-Castro, J; Movellan, J; Parrado, E; Rodas, G; Capdevila, L

2015-06-01

Our aim is to demonstrate the usefulness of photoplethysmography (PPG) for analyzing heart rate variability (HRV) using a standard 5-min test at rest with paced breathing, comparing the results with real RR intervals and testing supine and sitting positions. Simultaneous recordings of R-R intervals were conducted with a Polar system and a non-contact PPG, based on facial video recording on 20 individuals. Data analysis and editing were performed with individually designated software for each instrument. Agreement on HRV parameters was assessed with concordance correlations, effect size from ANOVA and Bland and Altman plots. For supine position, differences between video and Polar systems showed a small effect size in most HRV parameters. For sitting position, these differences showed a moderate effect size in most HRV parameters. A new procedure, based on the pixels that contained more heart beat information, is proposed for improving the signal-to-noise ratio in the PPG video signal. Results were acceptable in both positions but better in the supine position. Our approach could be relevant for applications that require monitoring of stress or cardio-respiratory health, such as effort/recuperation states in sports. © Georg Thieme Verlag KG Stuttgart · New York.

Origin of heart rate variability and turbulence: an appraisal of autonomic modulation of cardiovascular function.

Directory of Open Access Journals (Sweden)

Federico eLombardi

2011-12-01

Full Text Available Assessment of autonomic modulation of sinus node by non-invasive techniques has provided relevant clinical information in patients with several cardiac and non-cardiac diseases and has facilitated the appraisal of neural regulatory mechanisms in normal and diseased subjects. The finding that even during resting conditions the heart period changes on a beat to beat basis and that after a premature ventricular beat there are small variations in RR interval whose measurements may be utilised to evaluate the autonomic modulation of sinus node, has provided unprecedented clinical and pathophysiological information. Heart rate variability (HRV and Heart Rate Turbulence (HRT have been extensively utilised in the clinical setting. To explain the negative predictive value of a reduced HRV it was determined that overall HRV was largely dependent on vagal mechanisms and that a reduction in HRV could reflect an increased sympathetic and a reduced vagal modulation of sinus node; i.e. an autonomic alteration favouring cardiac electrical instability. This initial interpretation was challenged by several findings indicating a greater complexity of the relationship between neural input and sinus node responsiveness as well as the possible interference with non-neural mechanisms.Under controlled conditions, however, the computation of low and high frequency components and of their ratio seems capable of providing adequate information on sympatho-vagal balance in normal subjects as well as in most patients with a preserved left ventricular function, thus providing a unique tool to investigate neural control mechanisms. Analysis on non-linear dynamics of HRV has also been utilised to describe the fractal like characteristic of the variability signal and proven effective to identify patients at risk for sudden cardiac death. A reduction on HRT parameters reflecting reduced baroreflex sensitivity as a likely result of a reduced vagal and of an increased sympathetic

Self-esteem fluctuations and cardiac vagal control in everyday life.

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Schwerdtfeger, Andreas R; Scheel, Sophie-Marie

2012-03-01

It has been proposed that self-esteem buffers threat-responding. The same effect is ascribed to the vagus nerve, which is a primary nerve of the parasympathetic nervous system. Consequently, it has been suggested that self-esteem and cardiac vagal tone are interconnected on a trait, as well as on a state, level. In this study, we examined the relationship of vagal cardiac control and self-esteem fluctuations across a single day using ecological momentary assessment. Eighty-four participants were recruited, and self-esteem, negative affect, and vagal tone were recorded throughout a 22-hour period. Men provided higher self-esteem ratings than women, but the negative relationship between self-esteem and negative affect was stronger in women. Moreover, controlling for potential confounds (e.g., age, BMI, depressive symptoms, smoking status, regular physical activity), we observed that for men, self-esteem was significantly positively associated with cardiac vagal tone, whereas for women it was not. These findings suggest that the relationship between self-esteem and vagal innervation of the heart during daily life is sex-specific and might involve different central-autonomic pathways for men and women, respectively. Copyright © 2011 Elsevier B.V. All rights reserved.

Heart Rate Variability (HRV biofeedback: A new training approach for operator’s performance enhancement

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Auditya Purwandini Sutarto

2010-06-01

Full Text Available The widespread implementation of advanced and complex systems requires predominantly operators’ cognitive functions and less importance of human manual control. On the other hand, most operators perform their cognitive functions below their peak cognitive capacity level due to fatigue, stress, and boredom. Thus, there is a need to improve their cognitive functions during work. The goal of this paper is to present a psychophysiology training approach derived from cardiovascular response named heart rate variability (HRV biofeedback. Description of resonant frequency biofeedback - a specific HRV training protocol - is discussed as well as its supported researches for the performance enhancement. HRV biofeedback training works by teaching people to recognize their involuntary HRV and to control patterns of this physiological response. The training is directed to increase HRV amplitude that promotes autonomic nervous system balance. This balance is associated with improved physiological functioning as well as psychological benefits. Most individuals can learn HRV biofeedback training easily which involves slowing the breathing rate (around six breaths/min to each individual’s resonant frequency at which the amplitude of HRV is maximized. Maximal control over HRV can be obtained in most people after approximately four sessions of training. Recent studies have demonstrated the effectiveness of HRV biofeedback to the improvement of some cognitive functions in both simulated and real industrial operators.

Breathing exercises with vagal biofeedback may benefit patients with functional dyspepsia.

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Hjelland, Ina E; Svebak, Sven; Berstad, Arnold; Flatabø, Geir; Hausken, Trygve

2007-09-01

Many patients with functional dyspepsia (FD) have postprandial symptoms, impaired gastric accommodation and low vagal tone. The aim of this study was to improve vagal tone, and thereby also drinking capacity, intragastric volume and quality of life, using breathing exercises with vagal biofeedback. Forty FD patients were randomized to either a biofeedback group or a control group. The patients received similar information and care. Patients in the biofeedback group were trained in breathing exercises, 6 breaths/min, 5 min each day for 4 weeks, using specially designed software for vagal biofeedback. Effect variables included maximal drinking capacity using a drink test (Toro clear meat soup 100 ml/min), intragastric volume at maximal drinking capacity, respiratory sinus arrhythmia (RSA), skin conductance (SC) and dyspepsia-related quality of life scores. Drinking capacity and quality of life improved significantly more in the biofeedback group than in the control group (p=0.02 and p=0.01) without any significant change in baseline autonomic activity (RSA and SC) or intragastric volume. After the treatment period, RSA during breathing exercises was significantly correlated to drinking capacity (r=0.6, p=0.008). Breathing exercises with vagal biofeedback increased drinking capacity and improved quality of life in FD patients, but did not improve baseline vagal tone.

Very low frequency oscillations in the power spectra of heart rate variability during dry supine immersion and exposure to non-hypoxic hypobaria.

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Tripathi, K K

2011-06-01

The origin of very low frequency (VLF) oscillations in the power spectra of heart rate variability (HRV) is controversial with possible mechanisms involving thermoregulation and/or renin-angiotensin-aldosterone system. Recently, a major contribution from vagal influences has been suggested. The present study investigated the behaviour of VLF (0.004-0.040 Hz) components of HRV power spectra in a group of healthy male volunteers during their exposure to (1) dry, supine, immersion in thermo-neutral water for 6 h (n = 7) and (2) non-hypoxic hypobaria (breathing 40-60% oxygen at 15,000' simulated in a decompression chamber) for 5 h (n = 15). The two manoeuvres are established to increase vagal outflow. During both the manoeuvres, all the frequency domain indices of HRV exhibited a significant increase. Increase in HRV was much more than that in the R-R interval. At 6 h of immersion, the R-R interval increased by ∼ 15% but the total power increased ∼ fourfold. Similarly, at 5 h of exposure to hypobaria, total power increased ∼ twofold with a very modest increase in an R-R of ∼ 9%. Increase in spectral power was appreciable even after normalization with mean R-R(2). Increase in VLF during immersion was more than reported during enalaprilat blockade of angiotensin convertase enzyme. Plasma renin activity did not vary during hypobaria. There was a significant increase in pNN50, an established marker of cardiac vagal activity. Centre frequencies of the spectra and slope (β) of the relation between log(PSD) and log(frequency) did not change. Results were supportive of the notion that the parasympathetic system is pre-potent to influence slower (than respiratory) frequency components in HRV spectrum. Additionally, such an effect was without a change in the time constant of effector responses or pacemaker frequencies of VLF and LF periodicities and HRV was not a simple linear surrogate for cardiac vagal effects. An invariance of spectral exponent (β) ruled out

State-related differences in heart rate variability in bipolar disorder

DEFF Research Database (Denmark)

Faurholt-Jepsen, Maria; Brage, Søren; Kessing, Lars Vedel

2017-01-01

Heart rate variability (HRV) is a validated measure of sympato-vagal balance in the autonomic nervous system. HRV appears decreased in patients with bipolar disorder (BD) compared with healthy individuals, but the extent of state-related alterations has been sparingly investigated. The present...... bipolar disorder and could...

Genetic loci associated with heart rate variability and their effects on cardiac disease risk

NARCIS (Netherlands)

Nolte, Ilja M; Munoz, M Loretto; Tragante, Vinicius; Amare, Azmeraw T; Jansen, Rick; Vaez, Ahmad; von der Heyde, Benedikt; Avery, Christy L; Bis, Joshua C; Dierckx, Bram; van Dongen, Jenny; Gogarten, Stephanie M; Goyette, Philippe; Hernesniemi, Jussi; Huikari, Ville; Hwang, Shih-Jen; Jaju, Deepali; Kerr, Kathleen F; Kluttig, Alexander; Krijthe, Bouwe P; Kumar, Jitender; van der Laan, Sander W; Lyytikäinen, Leo-Pekka; Maihofer, Adam X; Minassian, Arpi; van der Most, Peter J; Müller-Nurasyid, Martina; Nivard, Michel; Salvi, Erika; Stewart, James D; Thayer, Julian F; Verweij, Niek; Wong, Andrew; Zabaneh, Delilah; Zafarmand, Mohammad H; Abdellaoui, Abdel; Albarwani, Sulayma; Albert, Christine; Alonso, Alvaro; Ashar, Foram; Auvinen, Juha; Axelsson, Tomas; Baker, Dewleen G; de Bakker, Paul I W; Barcella, Matteo; Bayoumi, Riad; Bieringa, Rob J; Boomsma, Dorret; Boucher, Gabrielle; Britton, Annie R; Christophersen, Ingrid; Dietrich, Andrea; Ehret, George B; Ellinor, Patrick T; Eskola, Markku; Felix, Janine F; Floras, John S; Franco, Oscar H; Friberg, Peter; Gademan, Maaike G J; Geyer, Mark A; Giedraitis, Vilmantas; Hartman, Catharina A; Hemerich, Daiane; Hofman, Albert; Hottenga, Jouke-Jan; Huikuri, Heikki; Hutri-Kähönen, Nina; Jouven, Xavier; Junttila, Juhani; Juonala, Markus; Kiviniemi, Antti M; Kors, Jan A.; Kumari, Meena; Kuznetsova, Tatiana; Laurie, Cathy C; Lefrandt, Joop D.; Li, Yong; Li, Yun; Liao, Duanping; Limacher, Marian C; Lin, Henry J; Lindgren, Cecilia M; Lubitz, Steven A; Mahajan, Anubha; McKnight, Barbara; Zu Schwabedissen, Henriette Meyer; Milaneschi, Yuri; Mononen, Nina; Morris, Andrew P; Nalls, Mike A; Navis, Gerjan; Neijts, Melanie; Nikus, Kjell; North, Kari E; O'Connor, Daniel T; Ormel, Johan; Perz, Siegfried; Peters, Annette; Psaty, Bruce M; Raitakari, Olli T; Risbrough, Victoria B; Sinner, Moritz F; Siscovick, David; Smit, Johannes H; Smith, Nicholas L; Soliman, Elsayed Z; Sotoodehnia, Nona; Staessen, Jan A; Stein, Phyllis K; Stilp, Adrienne M; Stolarz-Skrzypek, Katarzyna; Strauch, Konstantin; Sundström, Johan; Swenne, Cees A.; Syvänen, Ann-Christine; Tardif, Jean-Claude; Taylor, Kent D; Teumer, Alexander; Thornton, Timothy A; Tinker, Lesley E; Uitterlinden, André G; van Setten, Jessica; Voss, Andreas; Waldenberger, Melanie; Wilhelmsen, Kirk C; Willemsen, Gonneke; Wong, Quenna; Zhang, Zhu-Ming; Zonderman, Alan B; Cusi, Daniele; Evans, Michele K; Greiser, Halina K; van der Harst, Pim; Hassan, Mohammad; Ingelsson, Erik; Järvelin, Marjo-Riitta; Kääb, Stefan; Kähönen, Mika; Kivimaki, Mika; Kooperberg, Charles; Kuh, Diana; Lehtimäki, Terho; Lind, Lars; Nievergelt, Caroline M; O'Donnell, Chris J; Oldehinkel, Albertine J; Penninx, Brenda; Reiner, Alexander P; Riese, Harriëtte; Van Roon, Arie M.; Rioux, John D; Rotter, Jerome I; Sofer, Tamar; Stricker, Bruno H; Tiemeier, Henning; Vrijkotte, Tanja G M; Asselbergs, Folkert W; Brundel, Bianca J J M; Heckbert, Susan R; Whitsel, Eric A; den Hoed, Marcel; Snieder, Harold; de Geus, Eco J C

2017-01-01

Reduced cardiac vagal control reflected in low heart rate variability (HRV) is associated with greater risks for cardiac morbidity and mortality. In two-stage meta-analyses of genome-wide association studies for three HRV traits in up to 53,174 individuals of European ancestry, we detect 17

cHRV Uncovering Daily Stress Dynamics Using Bio-Signal from Consumer Wearables.

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Hao, Tian; Chang, Henry; Ball, Marion; Lin, Kun; Zhu, Xinxin

2017-01-01

Knowing the dynamics of one's daily stress is essential to effective stress management in the context of smart and connected health. However, there lacks a practical and unobtrusive means to obtain real-time and longitudinal stress information. In this paper, we attempt to derive a convenient HRV-based (heart rate variability) biomarker named cHRV, which can be used to reliably reflect stress dynamics. cHRV's key advantage lies in its low maintenance and high practicality. It can be efficiently calculated only using data from photoplethysmography (PPG) sensors, the mainstream heart rate sensor embedded in most of the consumer wearables like Apple Watch. Benefiting from the proliferation of wearables, cHRV is ideal for day-to-day stress monitoring. To evaluate its feasibility and performance, we have conducted 14 in-lab controlled experiments. The result shows that the proposed cHRV has strong correlation with the stress dynamics (r > 0.95), therefore exhibits great potential for continuous stress assessment.

The anxiolytic effect of Bifidobacterium longum NCC3001 involves vagal pathways for gut-brain communication.

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Bercik, P; Park, A J; Sinclair, D; Khoshdel, A; Lu, J; Huang, X; Deng, Y; Blennerhassett, P A; Fahnestock, M; Moine, D; Berger, B; Huizinga, J D; Kunze, W; McLean, P G; Bergonzelli, G E; Collins, S M; Verdu, E F

2011-12-01

The probiotic Bifidobacterium longum NCC3001 normalizes anxiety-like behavior and hippocampal brain derived neurotrophic factor (BDNF) in mice with infectious colitis. Using a model of chemical colitis we test whether the anxiolytic effect of B. longum involves vagal integrity, and changes in neural cell function. Methods  Mice received dextran sodium sulfate (DSS, 3%) in drinking water during three 1-week cycles. Bifidobacterium longum or placebo were gavaged daily during the last cycle. Some mice underwent subdiaphragmatic vagotomy. Behavior was assessed by step-down test, inflammation by myeloperoxidase (MPO) activity and histology. BDNF mRNA was measured in neuroblastoma SH-SY5Y cells after incubation with sera from B. longum- or placebo-treated mice. The effect of B. longum on myenteric neuron excitability was measured using intracellular microelectrodes. Chronic colitis was associated with anxiety-like behavior, which was absent in previously vagotomized mice. B. longum normalized behavior but had no effect on MPO activity or histological scores. Its anxiolytic effect was absent in mice with established anxiety that were vagotomized before the third DSS cycle. B. longum metabolites did not affect BDNF mRNA expression in SH-SY5Y cells but decreased excitability of enteric neurons. In this colitis model, anxiety-like behavior is vagally mediated. The anxiolytic effect of B. longum requires vagal integrity but does not involve gut immuno-modulation or production of BDNF by neuronal cells. As B. longum decreases excitability of enteric neurons, it may signal to the central nervous system by activating vagal pathways at the level of the enteric nervous system. © 2011 Blackwell Publishing Ltd.

Gut vagal afferents differentially modulate innate anxiety and learned fear.

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Klarer, Melanie; Arnold, Myrtha; Günther, Lydia; Winter, Christine; Langhans, Wolfgang; Meyer, Urs

2014-05-21

Vagal afferents are an important neuronal component of the gut-brain axis allowing bottom-up information flow from the viscera to the CNS. In addition to its role in ingestive behavior, vagal afferent signaling has been implicated modulating mood and affect, including distinct forms of anxiety and fear. Here, we used a rat model of subdiaphragmatic vagal deafferentation (SDA), the most complete and selective vagal deafferentation method existing to date, to study the consequences of complete disconnection of abdominal vagal afferents on innate anxiety, conditioned fear, and neurochemical parameters in the limbic system. We found that compared with Sham controls, SDA rats consistently displayed reduced innate anxiety-like behavior in three procedures commonly used in preclinical rodent models of anxiety, namely the elevated plus maze test, open field test, and food neophobia test. On the other hand, SDA rats exhibited increased expression of auditory-cued fear conditioning, which specifically emerged as attenuated extinction of conditioned fear during the tone re-exposure test. The behavioral manifestations in SDA rats were associated with region-dependent changes in noradrenaline and GABA levels in key areas of the limbic system, but not with functional alterations in the hypothalamus-pituitary-adrenal grand stress. Our study demonstrates that innate anxiety and learned fear are both subjected to visceral modulation through abdominal vagal afferents, possibly via changing limbic neurotransmitter systems. These data add further weight to theories emphasizing an important role of afferent visceral signals in the regulation of emotional behavior. Copyright © 2014 the authors 0270-6474/14/347067-10$15.00/0.

A pilot study on quantification of training load: The use of HRV in training practice.

Science.gov (United States)

Saboul, Damien; Balducci, Pascal; Millet, Grégoire; Pialoux, Vincent; Hautier, Christophe

2016-01-01

Recent laboratory studies have suggested that heart rate variability (HRV) may be an appropriate criterion for training load (TL) quantification. The aim of this study was to validate a novel HRV index that may be used to assess TL in field conditions. Eleven well-trained long-distance male runners performed four exercises of different duration and intensity. TL was evaluated using Foster and Banister methods. In addition, HRV measurements were performed 5 minutes before exercise and 5 and 30 minutes after exercise. We calculated HRV index (TLHRV) based on the ratio between HRV decrease during exercise and HRV increase during recovery. HRV decrease during exercise was strongly correlated with exercise intensity (R = -0.70; p HRV changes during exercise and recovery phase are affected by both intensity and physiological impact of the exercise. Since the TLHRV formula takes into account the disturbance and the return to homeostatic balance induced by exercise, this new method provides an objective and rational TL index. However, some simplification of the protocol measurement could be envisaged for field use.

Heart rate variability in major depressive disorder and after antidepressant treatment with agomelatine and paroxetine: Findings from the Taiwan Study of Depression and Anxiety (TAISDA).

Science.gov (United States)

Yeh, Ta-Chuan; Kao, Lien-Cheng; Tzeng, Nian-Sheng; Kuo, Terry B J; Huang, San-Yuan; Chang, Chuan-Chia; Chang, Hsin-An

2016-01-04

Evidence from previous studies suggests that heart rate variability (HRV) is reduced in major depressive disorder (MDD). However, whether this reduction is attributable to the disorder per se or to medication, since antidepressants may also affect HRV, is still debated. There is a dearth of information regarding the effects of agomelatine, a novel antidepressant, on HRV. Here, we investigated whether HRV is reduced in MDD and compared the effects of agomelatine and paroxetine on HRV. We recruited 618 physically healthy unmedicated patients with MDD and 506 healthy volunteers aged 20-65 years. Frequency-domain measures of resting HRV were obtained at the time of enrollment for all participants. For patients with MDD, these measures were obtained again after 6 weeks of either agomelatine or paroxetine monotherapy. Compared with healthy subjects, unmedicated patients with MDD exhibited significantly lower variance (total HRV), low frequency (LF), and high frequency (HF) HRV, and a higher LF/HF ratio. Depression severity independently contributed to decreased HRV and vagal tone. Fifty-six patients completed the open-label trial (n=29 for agomelatine, n=27 for paroxetine). Between-group analyses showed a significant group-by-time interaction for LF-HRV and HF-HRV, driven by increases in LF-HRV and HF-HRV only after agomelatine treatment. Within the paroxetine-treated group, there were no significant changes in mean R-R intervals or any HRV indices. We therefore concluded that MDD is associated with reduced HRV, which is inversely related to depression severity. Compared with paroxetine, agomelatine has a more vagotonic effect, suggesting greater cardiovascular safety. Clinicians should consider HRV effects while selecting antidepressants especially for depressed patients who already have decreased cardiac vagal tone. Copyright © 2015 Elsevier Inc. All rights reserved.

Promotion of Viral IRES-Mediated Translation Initiation under Mild Hypothermia.

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Maria Licursi

Full Text Available Internal ribosome entry site (IRES-mediated translation is an essential replication step for certain viruses. As IRES-mediated translation is regulated differently from cap-dependent translation under various cellular conditions, we sought to investigate whether temperature influences efficiency of viral IRES-mediated translation initiation by using bicistronic reporter constructs containing an IRES element of encephalomyocarditis virus (EMCV, foot-and-mouth disease virus (FMDV, hepatitis C virus (HCV, human rhinovirus (HRV or poliovirus (PV. Under mild hypothermic conditions (30 and 35°C, we observed increases in the efficiency of translation initiation by HCV and HRV IRES elements compared to translation initiation at 37°C. The promotion of HRV IRES activity was observed as early as 2 hours after exposure to mild hypothermia. We also confirmed the promotion of translation initiation by HRV IRES under mild hypothermia in multiple cell lines. The expression levels and locations of polypyrimidine tract-binding protein (PTB and upstream of N-Ras (unr, the IRES trans-acting factors (ITAFs of HCV and HRV IRES elements, were not modulated by the temperature shift from 37°C to 30°C. Taken together, this study demonstrates that efficiency of translation initiation by some viral IRES elements is temperature dependent.

Depression impacts the physiological responsiveness of mother–daughter dyads during social interaction

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Amole, Marlissa C.; Cyranowski, Jill M.; Wright, Aidan G. C.; Swartz, Holly A.

2017-01-01

Background Maternal depression is associated with increased risk of psychiatric illness in offspring. While risk may relate to depressed mothers' difficulties regulating emotions in the context of interacting with offspring, physiological indicators of emotion regulation have rarely been examined during mother–child interactions—and never among mother–adolescent dyads in which both mother and adolescent have histories of major depressive disorder (MDD). Methods We examined changes in high-frequency heart rate variability (HF-HRV), an indicator of parasympathetic (vagal) function that has been related to depression, stress, social engagement, and emotion regulation, in 46 mother–daughter dyads (23 in which both mother and daughter had an MDD history and 23 never-depressed controls). Hierarchical linear models evaluated changes in HF-HRV while mother–daughter dyads engaged in discussions about shared pleasant events and relationship conflicts. Results While control dyads displayed positive slopes (increases) in HF-HRV during both discussions, MDD dyads displayed minimal change in HF-HRV across discussions. Among controls, HF-HRV slopes were positively correlated between mothers and daughters during the pleasant events' discussion. In contrast, HF-HRV slopes were negatively correlated between MDD mothers and daughters during both discussions. Conclusions Vagal responses observed in control mother–daughter dyads suggest a pattern of physiological synchrony and reciprocal positive social engagement, which may play a role in adolescent development of secure social attachments and healthy emotion regulation. In contrast, MDD mothers and daughters displayed diminished and discordant patterns of vagal responsiveness. More research is needed to understand the development and consequences of these patterns of parasympathetic responses among depressed mother–daughter dyads. PMID:28060443

Depression impacts the physiological responsiveness of mother-daughter dyads during social interaction.

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Amole, Marlissa C; Cyranowski, Jill M; Wright, Aidan G C; Swartz, Holly A

2017-02-01

Maternal depression is associated with increased risk of psychiatric illness in offspring. While risk may relate to depressed mothers' difficulties regulating emotions in the context of interacting with offspring, physiological indicators of emotion regulation have rarely been examined during mother-child interactions-and never among mother-adolescent dyads in which both mother and adolescent have histories of major depressive disorder (MDD). We examined changes in high-frequency heart rate variability (HF-HRV), an indicator of parasympathetic (vagal) function that has been related to depression, stress, social engagement, and emotion regulation, in 46 mother-daughter dyads (23 in which both mother and daughter had an MDD history and 23 never-depressed controls). Hierarchical linear models evaluated changes in HF-HRV while mother-daughter dyads engaged in discussions about shared pleasant events and relationship conflicts. While control dyads displayed positive slopes (increases) in HF-HRV during both discussions, MDD dyads displayed minimal change in HF-HRV across discussions. Among controls, HF-HRV slopes were positively correlated between mothers and daughters during the pleasant events' discussion. In contrast, HF-HRV slopes were negatively correlated between MDD mothers and daughters during both discussions. Vagal responses observed in control mother-daughter dyads suggest a pattern of physiological synchrony and reciprocal positive social engagement, which may play a role in adolescent development of secure social attachments and healthy emotion regulation. In contrast, MDD mothers and daughters displayed diminished and discordant patterns of vagal responsiveness. More research is needed to understand the development and consequences of these patterns of parasympathetic responses among depressed mother-daughter dyads. © 2016 Wiley Periodicals, Inc.

Heart rate variability and implication for sport concussion.

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Bishop, Scott A; Dech, Ryan T; Guzik, Przemyslaw; Neary, J Patrick

2017-11-16

Finding sensitive and specific markers for sports-related concussion is both challenging and clinically important. Such biomarkers might be helpful in the management of patients with concussion (i.e. diagnosis, monitoring and risk prediction). Among many parameters, blood flow-pressure metrics and heart rate variability (HRV) have been used to gauge concussion outcomes. Reports on the relation between HRV and both acute and prolonged concussion recovery are conflicting. While some authors report on differences in the low-frequency (LF) component of HRV during postural manipulations and postexercise conditions, others observe no significant differences in various HRV measures. Despite the early success of using the HRV LF for concussion recovery, the interpretation of the LF is debated. Recent research suggests the LF power is a net effect of several intrinsic modulatory factors from both sympathetic and parasympathetic branches of the autonomic nervous system, vagally mediated baroreflex and even some respiratory influences at lower respiratory rate. There are only a few well-controlled concussion studies that specifically examine the contribution of the autonomic nervous system branches with HRV for concussion management. This study reviews the most recent HRV- concussion literature and the underlying HRV physiology. It also highlights cerebral blood flow studies related to concussion and the importance of multimodal assessment of various biological signals. It is hoped that a better understanding of the physiology behind HRV might generate cost-effective, repeatable and reliable protocols, all of which will improve the interpretation of HRV throughout concussion recovery. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Vagal Blocking for Obesity Control

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Johannessen, Helene; Revesz, David; Kodama, Yosuke

2017-01-01

: VBLOC reduced body weight and food intake, which was associated with increased satiety but not with decreased hunger. Brain activities in response to VBLOC included increased gene expression of leptin and CCKb receptors, interleukin-1β, tumor necrosis factor, and transforming growth factor β1......BACKGROUND: Recently, the US FDA has approved "vagal blocking therapy or vBLoc® therapy" as a new treatment for obesity. The aim of the present study was to study the mechanism-of-action of "VBLOC" in rat models. METHODS: Rats were implanted with VBLOC, an intra-abdominal electrical device...... with leads placed around gastric vagal trunks through an abdominal incision and controlled by wireless device. Body weight, food intake, hunger/satiety, and metabolic parameters were monitored by a comprehensive laboratory animal monitoring system. Brain-gut responses were analyzed physiologically. RESULTS...

Modulation of the masseteric reflex by gastric vagal afferents.

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Pettorossi, V E

1983-04-01

Several investigations have shown that the vagal nerve can affect the reflex responses of the masticatory muscles acting at level either of trigeminal motoneurons or of the mesencephalic trigeminal nucleus (MTN). The present experiments have been devoted to establish the origin of the vagal afferent fibres involved in modulating the masseteric reflex. In particular, the gastric vagal afferents were taken into consideration and selective stimulations of such fibres were performed in rabbit. Conditioning electrical stimulation of truncus vagalis ventralis (TVV) reduced the excitability of the MTN cells as shown by a decrease of the antidromic response recorded from the semilunar ganglion and elicited by MTN single-shock electrical stimulation. Sympathetic and cardiovascular influences were not involved in these responses. Mechanical stimulation of gastric receptors, by means of gastric distension, clearly diminished the amplitude of twitch tension of masseteric reflex and inhibited the discharge frequency of proprioceptive MTN units. The effect was phasic and depended upon the velocity of distension. Thus the sensory volleys originating from rapid adapting receptors reach the brain stem through vagal afferents and by means of a polysynaptic connection inhibits the masseteric reflex at level of MTN cells.

Malignant vagal paraganglioma

DEFF Research Database (Denmark)

Carlsen, Camilla S; Godballe, Christian; Krogdahl, Annelise S

2003-01-01

Approximately 20 cases of malignant vagal paragangliomas (MVP)have been reported in English literature. Malignancy is based on the presence of metastases. A careful preoperative evaluation is necessary to detect multicentricity and/or significant production of catecholamines. A new case of MVP...... treated with embolization and surgery is presented and the literature discussed. It is concluded, that preoperative embolization followed by radical surgical resection is a rational treatment of patients with unilateral MVP....

The role of human rhinovirus (HRV) species on asthma exacerbation severity in children and adolescents.

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Lambert, Katrina A; Prendergast, Luke A; Dharmage, Shyamali C; Tang, Mimi; O'Sullivan, Molly; Tran, Thomas; Druce, Julian; Bardin, Philip; Abramson, Michael J; Erbas, Bircan

2017-10-11

It is recognized that human rhinovirus (HRV) infection is an important factor in asthma exacerbations requiring hospitalization in children. However, previous studies have disagreed on the differential impact of various HRV species. We sought to assess the impact of HRV species on the severity of asthma exacerbations in children and adolescents. We also examined whether the effect of HRV species on severity was modified by age and gender. Virus strain was determined for 113 children with HRV detectable at the time of admission for asthma exacerbation. Patient characteristics were collected on admission and exacerbation severity was scored using several validated scales. HRV species by itself was not associated with moderate/severe vs. mild exacerbations. Boys with HRV-C infections were more likely (OR: 3.7, 95% CI: 1.2-13.4) to have a moderate/severe exacerbation than girls with HRV-C (p = 0.04 for interaction term). Higher odds were observed in younger boys (3 years old: OR: 9.1, 95% CI: 1.8-47.1 vs 5 years old: OR: 3.3, 95% CI: 0.9-11.8 vs 7 years old: OR: 1.2, 95% CI: 0.2-6.6). In contrast, children with HRV-C infection and sensitized to pollen during the pollen season were less likely to have moderate/severe exacerbations (p = 0.01 for the interaction term). Acute asthma exacerbations are more likely to be moderate/severe in boys under 5 years of age who had HRV-C infection on admission. The opposite was found in children with sensitization to pollen during pollen season.

Anorexia‐cachexia syndrome in hepatoma tumour‐bearing rats requires the area postrema but not vagal afferents and is paralleled by increased MIC‐1/GDF15

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Borner, Tito; Arnold, Myrtha; Ruud, Johan; Breit, Samuel N.; Langhans, Wolfgang; Lutz, Thomas A.; Blomqvist, Anders

2016-01-01

Abstract Background The cancer‐anorexia‐cachexia syndrome (CACS) negatively affects survival and therapy success in cancer patients. Inflammatory mediators and tumour‐derived factors are thought to play an important role in the aetiology of CACS. However, the central and peripheral mechanisms contributing to CACS are insufficiently understood. The area postrema (AP) and the nucleus tractus solitarii are two important brainstem centres for the control of eating during acute sickness conditions. Recently, the tumour‐derived macrophage inhibitory cytokine‐1 (MIC‐1) emerged as a possible mediator of cancer anorexia because lesions of these brainstem areas attenuated the anorectic effect of exogenous MIC‐1 in mice. Methods Using a rat hepatoma tumour model, we examined the roles of the AP and of vagal afferents in the mediation of CACS. Specifically, we investigated whether a lesion of the AP (APX) or subdiaphragmatic vagal deafferentation (SDA) attenuate anorexia, body weight, muscle, and fat loss. Moreover, we analysed MIC‐1 levels in this tumour model and their correlation with tumour size and the severity of the anorectic response. Results In tumour‐bearing sham‐operated animals mean daily food intake significantly decreased. The anorectic response was paralleled by a significant loss of body weight and muscle mass. APX rats were protected against anorexia, body weight loss, and muscle atrophy after tumour induction. In contrast, subdiaphragmatic vagal deafferentation did not attenuate cancer‐induced anorexia or body weight loss. Tumour‐bearing rats had substantially increased MIC‐1 levels, which positively correlated with tumour size and cancer progression and negatively correlated with food intake. Conclusions These findings demonstrate the importance of the AP in the mediation of cancer‐dependent anorexia and body weight loss and support a pathological role of MIC‐1 as a tumour‐derived factor mediating CACS, possibly via an AP�

Asystole Following Profound Vagal Stimulation During Hepatectomy

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Preeta John

2008-01-01

Full Text Available Asystole in a non laparoscopic upper abdominal surgery following intense vagal stimulation is a rare event. This case report highlights the need for awareness of such a complication when a thoracic epidural anaesthetic has been given in addition to a general anaesthetic for an upper abdominal procedure. A combined thoracic epidural and general anaesthetic was given. The anterior abdominal wall was retracted forty minutes after administration of the epidural bolus. This maneuver resulted in a profound vagal response with bradycardia and asystole. The patient was resuscitated successfully with a cardiac massage, atropine and adrenaline and the surgery was resumed. Surgery lasted eleven hours and was uneventful.

Transcutaneous cervical vagal nerve stimulation modulates cardiac vagal tone and tumor necrosis factor-alpha

DEFF Research Database (Denmark)

Brock, C; Brock, B; Aziz, Q

2017-01-01

-VNS, there was an increase in cardiac vagal tone and a reduction in tumor necrosis factor-α in comparison to baseline. No change was seen in blood pressure, cardiac sympathetic index or other cytokines. These preliminary data suggest that t-VNS exerts an autonomic and a subtle antitumor necrosis factor-α effect, which...

Acute Vagal Nerve Stimulation Lowers α2 Adrenoceptor Availability

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Landau, Anne M.; Dyve, Suzan; Jakobsen, Steen

2015-01-01

Background Vagal nerve stimulation (VNS) emerged as an anti-epileptic therapy, and more recently as a potential antidepressant intervention. Objective/hypothesis We hypothesized that salutary effects of VNS are mediated, at least in part, by augmentation of the inhibitory effects of cortical...... monoaminergic neurotransmission at appropriate receptors, specifically adrenoceptors. Our objective was to measure the effect of acute VNS on α2 adrenoceptor binding. Methods Using positron emission tomography (PET), we measured changes in noradrenaline receptor binding associated with acute VNS stimulation...... electrode in minipigs before and within 30 min of the initiation of 1 mA stimulation. Kinetic analysis with the Logan graphical linearization generated tracer volumes of distribution for each condition. We used an averaged value of the distribution volume of non-displaceable ligand (VND), to calculate...

Constitutive overexpression of muscarinic receptors leads to vagal hyperreactivity.

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Angelo Livolsi

Full Text Available BACKGROUND: Alterations in muscarinic receptor expression and acetylcholinesterase (AchE activity have been observed in tissues from Sudden Infant Death Syndrome (SIDS. Vagal overactivity has been proposed as a possible cause of SIDS as well as of vasovagal syncopes. The aim of the present study was to seek whether muscarinic receptor overexpression may be the underlying mechanism of vagal hyperreactivity. Rabbits with marked vagal pauses following injection of phenylephrine were selected and crossed to obtain a vagal hyperreactive strain. The density of cardiac muscarinic receptors and acetylcholinesterase (AchE gene expression were assessed. Blood markers of the observed cardiac abnormalities were also sought. METHODOLOGY/PRINCIPAL FINDINGS: Cardiac muscarinic M(2 and M(3 receptors were overexpressed in hyperreactive rabbits compared to control animals (2.3-fold and 2.5-fold, respectively and the severity of the phenylephrine-induced bradycardia was correlated with their densities. A similar overexpression of M(2 receptors was observed in peripheral mononuclear white blood cells, suggesting that cardiac M(2 receptor expression can be inferred with high confidence from measurements in blood cells. Sequencing of the coding fragment of the M(2 receptor gene revealed a single nucleotide mutation in 83% of hyperreactive animals, possibly contributing for the transcript overexpression. Significant increases in AchE expression and activity were also assessed (AchE mRNA amplification ratio of 3.6 versus normal rabbits. This phenomenon might represent a compensatory consequence of muscarinic receptors overexpression. Alterations in M(2 receptor and AchE expression occurred between the 5th and the 7th week of age, a critical period also characterized by a higher mortality rate of hyperreactive rabbits (52% in H rabbits versus 13% in normal rabbits and preceeded the appearance of functional disorders. CONCLUSIONS/SIGNIFICANCE: The results suggest that

Autonomic and Brain Morphological Predictors of Stress Resilience

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Luca Carnevali

2018-04-01

Full Text Available Stressful life events are an important cause of psychopathology. Humans exposed to aversive or stressful experiences show considerable inter-individual heterogeneity in their responses. However, the majority does not develop stress-related psychiatric disorders. The dynamic processes encompassing positive and functional adaptation in the face of significant adversity have been broadly defined as resilience. Traditionally, the assessment of resilience has been confined to self-report measures, both within the general community and putative high-risk populations. Although this approach has value, it is highly susceptible to subjective bias and may not capture the dynamic nature of resilience, as underlying construct. Recognizing the obvious benefits of more objective measures of resilience, research in the field has just started investigating the predictive value of several potential biological markers. This review provides an overview of theoretical views and empirical evidence suggesting that individual differences in heart rate variability (HRV, a surrogate index of resting cardiac vagal outflow, may underlie different levels of resilience toward the development of stress-related psychiatric disorders. Following this line of thought, recent studies describing associations between regional brain morphometric characteristics and resting state vagally-mediated HRV are summarized. Existing studies suggest that the structural morphology of the anterior cingulated cortex (ACC, particularly its cortical thickness, is implicated in the expression of individual differences in HRV. These findings are discussed in light of emerging structural neuroimaging research, linking morphological characteristics of the ACC to psychological traits ascribed to a high-resilient profile and abnormal structural integrity of the ACC to the psychophysiological expression of stress-related mental health consequences. We conclude that a multidisciplinary approach

A novel heart rate control model provides insights linking LF-HRV behavior to the open-loop gain.

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Dvir, Hila; Bobrovsky, Ben Zion; Gabbay, Uri

2013-09-20

Low-frequency heart rate variability (LF-HRV) at rest has already been successfully modeled as self-sustained oscillations in a nonlinear control loop, but these models fail to simulate LF-HRV decreases either during aerobic exercise or in heart failure patients. Following control engineering practices, we assume the existence of a biological excitation (dither) within the heart rate control loop that softens the nonlinearity and studied LF-HRV behavior in a dither-embedded model. We adopted the Ottesen model with some revisions and induced a dither of high-frequency stochastic perturbations. We simulated scenarios of a healthy subject at rest and during aerobic exercise (by decreasing peripheral vascular resistance) and a heart failure patient (by decreasing stroke volume). The simulations resembled physiological LF-HRV behavior, i.e., LF-HRV decreased during aerobic exercise and in the heart failure patient. The simulations exhibited LF-HRV dependency on the open-loop gain, which is related to the product of the feedback gain and the feed forward gain. We are the first to demonstrate that LF-HRV may be dependent on the open-loop gain. Accordingly, reduced open-loop gain results in decreased LF-HRV, and vice versa. Our findings explain a well-known but unexplained observed phenomenon of reduced LF-HRV both in heart failure patients and in healthy subjects performing aerobic exercise. These findings have implications on how changes in LF-HRV can be interpreted physiologically, a necessary step towards the clinical utilization of LF-HRV. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Resting Heart Rate Variability, Facets of Rumination and Trait Anxiety: Implications for the Perseverative Cognition Hypothesis

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DeWayne P. Williams

2017-10-01

Full Text Available The perseverative cognition hypothesis (PCH posits that perseveration, defined as the repetitive or sustained activation of cognitive representations of a real or imagined stressor, is a primary mechanism linking psychological (or stress vulnerability with poor health and disease. Resting vagally mediated heart rate variability (vmHRV is an important indicator of self-regulatory abilities, stress vulnerability and overall health. Those with lower resting vmHRV are more vulnerable to stress, and thus more likely to engage in perseverative cognition and experience subsequent negative mental health outcomes such as anxiety. Recent research suggests that rumination—one of the core mechanisms underlying perseveration—is a construct containing (at least two maladaptive (depressive and brooding and one adaptive (reflective types of rumination. However, to date, research has not examined how the association between resting vmHRV may differ between these three facets of rumination, in addition to these facets’ mechanistic role in linking lower resting vmHRV with greater trait anxiety. The current cross-sectional study explores these relationships in a sample of 203 participants (112 females, 76 ethnic minorities, mean age = 19.43, standard deviation = 1.87. Resting vmHRV was assessed during a 5-min-resting period using an Electrocardiogram (ECG. Both trait rumination (including the three facets and anxiety were assessed via self-report scales. Significant negative associations were found between resting vmHRV and maladaptive, but not adaptive, forms of perseveration. Similarly, mediation analyses showed a significant indirect relationship between resting vmHRV and anxiety through maladaptive, but not adaptive, facets of rumination. Our findings support the PCH such that those with stress vulnerability, as indexed by lower resting vmHRV, are more likely to engage in maladaptive perseverative cognition and thus experience negative outcomes such as

Resting Heart Rate Variability, Facets of Rumination and Trait Anxiety: Implications for the Perseverative Cognition Hypothesis.

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Williams, DeWayne P; Feeling, Nicole R; Hill, LaBarron K; Spangler, Derek P; Koenig, Julian; Thayer, Julian F

2017-01-01

The perseverative cognition hypothesis (PCH) posits that perseveration, defined as the repetitive or sustained activation of cognitive representations of a real or imagined stressor, is a primary mechanism linking psychological (or stress) vulnerability with poor health and disease. Resting vagally mediated heart rate variability (vmHRV) is an important indicator of self-regulatory abilities, stress vulnerability and overall health. Those with lower resting vmHRV are more vulnerable to stress, and thus more likely to engage in perseverative cognition and experience subsequent negative mental health outcomes such as anxiety. Recent research suggests that rumination-one of the core mechanisms underlying perseveration-is a construct containing (at least) two maladaptive (depressive and brooding) and one adaptive (reflective) types of rumination. However, to date, research has not examined how the association between resting vmHRV may differ between these three facets of rumination, in addition to these facets' mechanistic role in linking lower resting vmHRV with greater trait anxiety. The current cross-sectional study explores these relationships in a sample of 203 participants (112 females, 76 ethnic minorities, mean age = 19.43, standard deviation = 1.87). Resting vmHRV was assessed during a 5-min-resting period using an Electrocardiogram (ECG). Both trait rumination (including the three facets) and anxiety were assessed via self-report scales. Significant negative associations were found between resting vmHRV and maladaptive, but not adaptive, forms of perseveration. Similarly, mediation analyses showed a significant indirect relationship between resting vmHRV and anxiety through maladaptive, but not adaptive, facets of rumination. Our findings support the PCH such that those with stress vulnerability, as indexed by lower resting vmHRV, are more likely to engage in maladaptive perseverative cognition and thus experience negative outcomes such as anxiety. Our data

During stress, heart rate variability moderates the impact of childhood adversity in women with breast cancer.

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Tell, Dina; Mathews, Herbert L; Burr, Robert L; Witek Janusek, Linda

2018-03-01

Childhood adversity has long-lasting neuro-biological effects that can manifest as exaggerated stress responsivity to environmental challenge. These manifestations include a dysregulated hypothalamic-pituitary-adrenocortical (HPA) axis as well as increased levels of inflammatory mediators in response to stress. In this investigation, vagal parasympathetic activity was assessed for its capacity to moderate the relationship between childhood adversity and stress responsivity (cortisol and inflammation) during an acute laboratory challenge (Trier Social Stress Test-TSST). Thirty women recently diagnosed with breast cancer underwent the TSST during which their heart rate was recorded and saliva samples collected for measurement of cortisol and the proinflammatory cytokine, IL-6. Vagal activity during the TSST was calculated as the high-frequency (HF) component of heart rate variability (HRV). Vagal activity during the TSST moderated the effect of childhood adversity on both the cortisol and the IL-6 response. Women who had lower vagal stress-reactivity during the TSST and reported greater childhood adversity showed a larger rise in cortisol and IL-6 when compared to women with lower childhood adversity. The findings demonstrate that women with exposure to childhood adversity and low vagal stress-reactivity (reduced parasympathetic activity) exhibit an elevated stress response characterized by greater cortisol and proinflammatory cytokine release. Inflammatory burden and HPA dysregulation subsequent to stress may impair cancer control.

Jugular and vagal paragangliomas: Systematic study of management with surgery and radiotherapy

NARCIS (Netherlands)

Suarez, C.; Rodrigo, J.P.; Bodeker, C.C.; Llorente, J.L.; Silver, C.E.; Jansen, J.C.; Takes, R.P.; Strojan, P.; Pellitteri, P.K.; Rinaldo, A.; Mendenhall, W.M.; Ferlito, A.

2013-01-01

BACKGROUND: The definitive treatment for head and neck paraganglioma (PG) is surgical excision. Unfortunately, surgery, particularly of vagal paraganglioma (VPG; "glomus vagale") and foramen jugulare ("glomus jugulare") tumors, may be complicated by injuries to the lower cranial nerves, a high price

HRV based Health&Sport markers using video from the face

OpenAIRE

Capdevila, Ll.; Moreno, Jordi; Movellan, Javier; Parrado Romero, Eva; Ramos Castro, Juan José

2012-01-01

Heart Rate Variability (HRV) is an indicator of health status in the general population and of adaptatio n to stress in athletes. In this paper we compare the performance of two systems to measure HRV: (1) A commercial system based on recording the physiological cardiac signal with (2) A computer vision system that uses a standard video images of the face to estimate RR from changes in skin color of the face. We show that the computer vision system pe...

Vagal modulation of resting heart rate in rats: the role of stress, psychosocial factors and physical exercise

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Luca eCarnevali

2014-03-01

Full Text Available In humans, there are large individual differences in the levels of vagal modulation of resting heart rate. High levels are a recognized index of cardiac health, whereas low levels are considered an important risk factor for cardiovascular morbidity and mortality. Several factors are thought to contribute significantly to this inter-individual variability. While regular physical exercise seems to induce an increase in resting vagal tone, chronic life stress and psychosocial factors such as negative moods and personality traits appear associated with vagal withdrawal. Preclinical research has been attempting to clarify such relationships and to provide insights into the neurobiological mechanisms underlying vagal tone impairment/enhancement. This paper focuses on rat studies that have explored the effects of stress, psychosocial factors and physical exercise on vagal modulation of resting heart rate. Results are discussed with regard to: (i individual differences in resting vagal tone, cardiac stress reactivity and arrhythmia vulnerability; (ii elucidation of the neurobiological determinants of resting vagal tone.

Accuracy of the Garmin 920 XT HRM to perform HRV analysis.

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Cassirame, Johan; Vanhaesebrouck, Romain; Chevrolat, Simon; Mourot, Laurent

2017-12-01

Heart rate variability (HRV) analysis is widely used to investigate autonomous cardiac drive. This method requires periodogram measurement, which can be obtained by an electrocardiogram (ECG) or from a heart rate monitor (HRM), e.g. the Garmin 920 XT device. The purpose of this investigation was to assess the accuracy of RR time series measurements from a Garmin 920 XT HRM as compared to a standard ECG, and to verify whether the measurements thus obtained are suitable for HRV analysis. RR time series were collected simultaneously with an ECG (Powerlab system, AD Instruments, Castell Hill, Australia) and a Garmin XT 920 in 11 healthy subjects during three conditions, namely in the supine position, the standing position and during moderate exercise. In a first step, we compared RR time series obtained with both tools using the Bland and Altman method to obtain the limits of agreement in all three conditions. In a second step, we compared the results of HRV analysis between the ECG RR time series and Garmin 920 XT series. Results show that the accuracy of this system is in accordance with the literature in terms of the limits of agreement. In the supine position, bias was 0.01, - 2.24, + 2.26 ms; in the standing position, - 0.01, - 3.12, + 3.11 ms respectively, and during exercise, - 0.01, - 4.43 and + 4.40 ms. Regarding HRV analysis, we did not find any difference for HRV analysis in the supine position, but the standing and exercise conditions both showed small modifications.

Obesity is associated with lack of inhibitory control and impaired heart rate variability reactivity and recovery in response to food stimuli.

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Spitoni, Grazia Fernanda; Ottaviani, Cristina; Petta, Anna Maria; Zingaretti, Pietro; Aragona, Massimiliano; Sarnicola, Antonio; Antonucci, Gabriella

2017-06-01

Recent theories compare obesity with addiction in terms of lack of inhibitory control in both clinical populations. The present study hypothesized impaired inhibition in obese patients reflected both in executive functions and reduced vagal tone (indexed by a decrease in heart rate variability; HRV) in response to food stimuli. Twenty-four inpatients with obesity (19 women) and 37 controls (24 women) underwent ECG monitoring during baseline, food stimuli viewing, and a recovery phase. Tests and questionnaires assessing inhibitory control and psychopathological dispositions were also administered. As hypothesized, patients were characterized by deficits in all the tests measuring inhibitory capacities. Results also show greater HRV reduction and impaired HRV recovery in response to food stimuli in obese patients compared to controls. The drive to eat experienced by obese patients in the absence of caloric need may rely on impairments in inhibitory and vagal functioning. Results are discussed in terms of implications for therapy. Copyright © 2017. Published by Elsevier B.V.

Anorexia-cachexia syndrome in hepatoma tumour-bearing rats requires the area postrema but not vagal afferents and is paralleled by increased MIC-1/GDF15.

Science.gov (United States)

Borner, Tito; Arnold, Myrtha; Ruud, Johan; Breit, Samuel N; Langhans, Wolfgang; Lutz, Thomas A; Blomqvist, Anders; Riediger, Thomas

2017-06-01

The cancer-anorexia-cachexia syndrome (CACS) negatively affects survival and therapy success in cancer patients. Inflammatory mediators and tumour-derived factors are thought to play an important role in the aetiology of CACS. However, the central and peripheral mechanisms contributing to CACS are insufficiently understood. The area postrema (AP) and the nucleus tractus solitarii are two important brainstem centres for the control of eating during acute sickness conditions. Recently, the tumour-derived macrophage inhibitory cytokine-1 (MIC-1) emerged as a possible mediator of cancer anorexia because lesions of these brainstem areas attenuated the anorectic effect of exogenous MIC-1 in mice. Using a rat hepatoma tumour model, we examined the roles of the AP and of vagal afferents in the mediation of CACS. Specifically, we investigated whether a lesion of the AP (APX) or subdiaphragmatic vagal deafferentation (SDA) attenuate anorexia, body weight, muscle, and fat loss. Moreover, we analysed MIC-1 levels in this tumour model and their correlation with tumour size and the severity of the anorectic response. In tumour-bearing sham-operated animals mean daily food intake significantly decreased. The anorectic response was paralleled by a significant loss of body weight and muscle mass. APX rats were protected against anorexia, body weight loss, and muscle atrophy after tumour induction. In contrast, subdiaphragmatic vagal deafferentation did not attenuate cancer-induced anorexia or body weight loss. Tumour-bearing rats had substantially increased MIC-1 levels, which positively correlated with tumour size and cancer progression and negatively correlated with food intake. These findings demonstrate the importance of the AP in the mediation of cancer-dependent anorexia and body weight loss and support a pathological role of MIC-1 as a tumour-derived factor mediating CACS, possibly via an AP-dependent action. © 2016 The Authors. Journal of Cachexia, Sarcopenia and Muscle

Parental Socialization, Vagal Regulation, and Preschoolers' Anxious Difficulties: Direct Mothers and Moderated Fathers

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Hastings, Paul D.; Sullivan, Caroline; McShane, Kelly E.; Coplan, Robert J.; Utendale, William T.; Vyncke, Johanna D.

2008-01-01

Parental supportiveness and protective overcontrol and preschoolers' parasympathetic regulation were examined as predictors of temperamental inhibition, social wariness, and internalizing problems. Lower baseline vagal tone and weaker vagal suppression were expected to mark poorer dispositional self-regulatory capacity, leaving children more…

Distinguishing molecular features and clinical characteristics of a putative new rhinovirus species, human rhinovirus C (HRV C.

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Peter McErlean

Full Text Available BACKGROUND: Human rhinoviruses (HRVs are the most frequently detected pathogens in acute respiratory tract infections (ARTIs and yet little is known about the prevalence, recurrence, structure and clinical impact of individual members. During 2007, the complete coding sequences of six previously unknown and highly divergent HRV strains were reported. To catalogue the molecular and clinical features distinguishing the divergent HRV strains, we undertook, for the first time, in silico analyses of all available polyprotein sequences and performed retrospective reviews of the medical records of cases in which variants of the prototype strain, HRV-QPM, had been detected. METHODOLOGY/PRINCIPLE FINDINGS: Genomic analyses revealed that the six divergent strains, residing within a clade we previously called HRV A2, had the shortest polyprotein of all picornaviruses investigated. Structure-based amino acid alignments identified conserved motifs shared among members of the genus Rhinovirus as well as substantive deletions and insertions unique to the divergent strains. Deletions mostly affected regions encoding proteins traditionally involved in antigenicity and serving as HRV and HEV receptor footprints. Because the HRV A2 strains cannot yet be cultured, we created homology models of predicted HRV-QPM structural proteins. In silico comparisons confirmed that HRV-QPM was most closely related to the major group HRVs. HRV-QPM was most frequently detected in infants with expiratory wheezing or persistent cough who had been admitted to hospital and required supplemental oxygen. It was the only virus detected in 65% of positive individuals. These observations contributed to an objective clinical impact ranging from mild to severe. CONCLUSIONS: The divergent strains did not meet classification requirements for any existing species of the genus Rhinovirus or Enterovirus. HRV A2 strains should be partitioned into at least one new species, putatively called Human

Exacerbation of electrical storm subsequent to implantation of a right vagal stimulator.

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Shalaby, Alaa A; El-Saed, Aiman; Nemec, Jan; Moossy, John J; Balzer, Jeffrey R

2007-12-01

A patient with advanced ischemic cardiomyopathy underwent implantation of a vagal stimulator in an attempt to control recurrent drug refractory ventricular arrhythmia. Electrical storm was exacerbated after the implant and continued after neurostimulation was discontinued. The report aims to provide a cautionary note to application of vagal stimulation for control of cardiac arrhythmia.

Central vagal sensory and motor connections: human embryonic and fetal development.

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Cheng, Gang; Zhou, Xiangtian; Qu, Jia; Ashwell, Ken W S; Paxinos, G

2004-07-30

The embryonic and fetal development of the nuclear components and pathways of vagal sensorimotor circuits in the human has been studied using Nissl staining and carbocyanine dye tracing techniques. Eight fetal brains ranging from 8 to 28 weeks of development had DiI (1,1'-dioctadecyl-3,3,3',3' tetramethylindocarbocyanine perchlorate) inserted into either the thoracic vagus nerve at the level of the sternal angle (two specimens of 8 and 9 weeks of gestation) or into vagal rootlets at the surface of the medulla (at all other ages), while a further five were used for study of cytoarchitectural development. The first central labeling resulting from peripheral application of DiI to the thoracic vagus nerve was seen at 8 weeks. By 9 weeks, labeled bipolar cells at the ventricular surface around the sulcus limitans (sl) were seen after DiI application to the thoracic vagus nerve. Subnuclear organization as revealed by both Nissl staining and carbocyanine dye tracing was found to be advanced at a relatively early fetal age, with afferent segregation in the medial Sol apparent at 13 weeks and subnuclear organization of efferent magnocellular divisions of dorsal motor nucleus of vagus nerve noticeable at the same stage. The results of the present study also confirm that vagal afferents are distributed to the dorsomedial subnuclei of the human nucleus of the solitary tract, with particular concentrations of afferent axons in the gelatinosus subnucleus. These vagal afferents appeared to have a restricted zone of termination from quite early in development (13 weeks) suggesting that there is no initial exuberance in the termination field of vagal afferents in the developing human nucleus of the solitary tract. On the other hand, the first suggestion of afferents invading 10N from the medial Sol was not seen until 20 weeks and was not well developed until 24 weeks, suggesting that direct monosynaptic connections between the sensory and effector components of the vagal

The effect of a single session of short duration biofeedback-induced deep breathing on measures of heart rate variability during laboratory-induced cognitive stress: a pilot study.

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Prinsloo, Gabriell E; Derman, Wayne E; Lambert, Michael I; Laurie Rauch, H G

2013-06-01

This study examines the acute effect of heart rate variability (HRV) biofeedback on HRV measures during and immediately after biofeedback and during the following laboratory-induced stress. Eighteen healthy males exposed to work-related stress were randomised into an HRV biofeedback group (BIO) or a comparative group (COM). Subjects completed a modified Stroop task before (Stroop 1) and after (Stroop 2) the intervention. Both groups had similar physiological responses to stress in Stroop 1. In Stroop 2, the COM group responded similarly to the way they did to Stroop 1: respiratory frequency (RF) and heart rate (HR) increased, RMSSD and high frequency (HF) power decreased or had a tendency to decrease, while low frequency (LF) power showed no change. The BIO group responded differently in Stroop 2: while RF increased and LF power decreased, HR, RMSSD and HF power showed no change. In the BIO group, RMSSD was higher in Stroop 2 compared to Stroop 1. In conclusion, HRV biofeedback induced a short term carry-over effect during both the following rest period and laboratory-induced stress suggesting maintained HF vagal modulation in the BIO group after the intervention, and maintained LF vagal modulation in the COM group.

Profiling of G protein-coupled receptors in vagal afferents reveals novel gut-to-brain sensing mechanisms.

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Egerod, Kristoffer L; Petersen, Natalia; Timshel, Pascal N; Rekling, Jens C; Wang, Yibing; Liu, Qinghua; Schwartz, Thue W; Gautron, Laurent

2018-06-01

G protein-coupled receptors (GPCRs) act as transmembrane molecular sensors of neurotransmitters, hormones, nutrients, and metabolites. Because unmyelinated vagal afferents richly innervate the gastrointestinal mucosa, gut-derived molecules may directly modulate the activity of vagal afferents through GPCRs. However, the types of GPCRs expressed in vagal afferents are largely unknown. Here, we determined the expression profile of all GPCRs expressed in vagal afferents of the mouse, with a special emphasis on those innervating the gastrointestinal tract. Using a combination of high-throughput quantitative PCR, RNA sequencing, and in situ hybridization, we systematically quantified GPCRs expressed in vagal unmyelinated Na v 1.8-expressing afferents. GPCRs for gut hormones that were the most enriched in Na v 1.8-expressing vagal unmyelinated afferents included NTSR1, NPY2R, CCK1R, and to a lesser extent, GLP1R, but not GHSR and GIPR. Interestingly, both GLP1R and NPY2R were coexpressed with CCK1R. In contrast, NTSR1 was coexpressed with GPR65, a marker preferentially enriched in intestinal mucosal afferents. Only few microbiome-derived metabolite sensors such as GPR35 and, to a lesser extent, GPR119 and CaSR were identified in the Na v 1.8-expressing vagal afferents. GPCRs involved in lipid sensing and inflammation (e.g. CB1R, CYSLTR2, PTGER4), and neurotransmitters signaling (CHRM4, DRD2, CRHR2) were also highly enriched in Na v 1.8-expressing neurons. Finally, we identified 21 orphan GPCRs with unknown functions in vagal afferents. Overall, this study provides a comprehensive description of GPCR-dependent sensing mechanisms in vagal afferents, including novel coexpression patterns, and conceivably coaction of key receptors for gut-derived molecules involved in gut-brain communication. Copyright © 2018 The Authors. Published by Elsevier GmbH.. All rights reserved.

Heart rate variability changes in business process outsourcing employees working in shifts.

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Kunikullaya, Kirthana U; Kirthi, Suresh K; Venkatesh, D; Goturu, Jaisri

2010-10-31

Irregular and poor quality sleep is common in business process outsourcing (BPO) employees due to continuous shift working. The influence of this on the cardiac autonomic activity was investigated by the spectral analysis of heart rate variability (HRV). 36 night shift BPO employees (working from 22:00 to 06:00h) and 36 age and sex matched day shift BPO employees (working from 08:00 to 16:00h) were recruited for the study. Five minute electrocardiogram (ECG) was recorded in all the subjects. Heart rate variability was analyzed by fast Fourier transformation using RMS Vagus HRV software. The results were analyzed using Mann Whitney U test, Student t-test, Wilcoxon signed rank test and were expressed as mean ± SD. Sleepiness was significantly higher among night shift workers as measured by Epworth Sleepiness Scale (p<0.001). Night shift BPO employees were found to have a trend towards lower values of vagal parameters - HF power (ms(2)), and higher values of sympathovagal parameters like LF Power (ms(2)) and the LF/HF power (%) suggesting decreased vagal activity and sympathetic over activity, when compared to day shift employees. However, HRV parameters did not vary significantly between the day shift employees and night shift workers baseline values, and also within the night shift group. Night shift working increased the heart rate and shifted the sympathovagal balance towards sympathetic dominance and decreased vagal parameters of HRV. This is an indicator of unfavorable change in the myocardial system, and thus shows increased risk of cardiovascular disease among the night shift employees.

The antiarrhythmic effect of vagal stimulation after acute coronary occlusion: Role of the heart rate.

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Manati, Waheed; Pineau, Julien; Doñate Puertas, Rosa; Morel, Elodie; Quadiri, Timour; Bui-Xuan, Bernard; Chevalier, Philippe

2018-01-03

Strong evidence suggests a causal link between autonomic disturbances and ventricular arrhythmias. However, the mechanisms underlying the antiarrhythmic effect of vagal stimulation are poorly understood. The vagal antiarrhythmic effect might be modulated by a decrease in heart rate. the proximal anterior interventricular artery was occluded in 16 pigs by clamping under general anaesthesia. Group 1: heart rates remained spontaneous (n = 6; 12 occlusions); Group 2: heart rates were fixed at 190 beats per minute (bpm) with atrial electrical stimulation (n = 10; 20 occlusions). Each pig received two occlusions, 30 min apart, one without and one with vagal stimulation (10 Hz, 2 ms, 5-20 mA). The antiarrhythmic effect of vagal activation was defined as the time to the appearance of ventricular fibrillation (VF) after occlusion. In Group 1, vagal stimulation triggered a significant decrease in basal heart rate (132 ± 4 vs. 110 ± 17 bpm, p coronary occlusion (1102 ± 85 vs. 925 ± 41 s, p acute coronary occlusion.

Anxiety, attention, and decision making: The moderating role of heart rate variability.

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Ramírez, Encarnación; Ortega, Ana Raquel; Reyes Del Paso, Gustavo A

2015-12-01

The current exploratory research examined whether high frequency heart rate variability (HF-HRV) modulates the association between anxiety and (1) executive attentional control during situations involving neutral stimuli, in which the distractor stimuli are in conflict with the target stimulus, and (2) risk aversion in decision making. Forty-five participants (21 with low and 24 with high trait-anxiety) performed a modified version of the Attention Network Test to measure attentional control, and the Balloon Analog Risk Task to measure risk aversion. HF-HRV was recorded during a rest period before completion of the tasks. Results showed that individuals with high anxiety and low HF-HRV have worse attentional control in the face of conflicting information as well as greater risk aversion, in comparison with individuals with both high anxiety and high HF-HRV or low anxiety (regardless of HF-HRV). HF-HRV was positively associated with attentional control and negatively associated with risk aversion. Furthermore, a strong negative association was observed between attentional control and risk aversion. These results suggest that HF-HRV modulates the influence of anxiety on both attentional control to neutral stimuli, and risk aversion in decision making. Greater HF-HRV appears to fulfill a protective role in highly anxious individuals. The associations observed also suggest that executive control of attention plays a relevant role in decision making. These results support the relevance of the autonomic nervous system in sustained cognition and are in accordance with theories in which vagal-mediated heart rate variability is taken as an indicator of prefrontal cortex inhibitory influences. Copyright © 2015 Elsevier B.V. All rights reserved.

Yoga and heart rate variability: A comprehensive review of the literature

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Anupama Tyagi

2016-01-01

Full Text Available Heart rate variability (HRV has been used as a proxy for health and fitness and indicator of autonomic regulation and therefore, appears well placed to assess the changes occurring with mind.-body practices that facilitate autonomic balance. While many studies suggest that yoga influences HRV, such studies have not been systematically reviewed. We aimed to systematically review all published papers that report on yoga practices and HRV. A comprehensive search of multiple databases was conducted and all studies that reported a measure of HRV associated with any yoga practice were included. Studies were categorized by the study design and type of yoga practice. A total of 59 studies were reviewed involving a total of 2358 participants. Most studies were performed in India on relatively small numbers of healthy male yoga practitioners during a single laboratory session. Of the reviewed studies, 15 were randomized controlled trials with 6 having a Jadad score of 3. The reviewed studies suggest that yoga can affect cardiac autonomic regulation with increased HRV and vagal dominance during yoga practices. Regular yoga practitioners were also found to have increased vagal tone at rest compared to non-yoga practitioners. It is premature to draw any firm conclusions about yoga and HRV as most studies were of poor quality, with small sample sizes and insufficient reporting of study design and statistical methods. Rigorous studies with detailed reporting of yoga practices and any corresponding changes in respiration are required to determine the effect of yoga on HRV.

Effects of a hydrotherapy programme on symbolic and complexity dynamics of heart rate variability and aerobic capacity in fibromyalgia patients.

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Zamunér, Antonio Roberto; Andrade, Carolina P; Forti, Meire; Marchi, Andrea; Milan, Juliana; Avila, Mariana Arias; Catai, Aparecida Maria; Porta, Alberto; Silva, Ester

2015-01-01

To evaluate the effects of a hydrotherapy programme on aerobic capacity and linear and non-linear dynamics of heart rate variability (HRV) in women with fibromyalgia syndrome (FMS). 20 women with FMS and 20 healthy controls (HC) took part in the study. The FMS group was evaluated at baseline and after a 16-week hydrotherapy programme. All participants underwent cardiopulmonary exercise testing on a cycle ergometer and RR intervals recording in supine and standing positions. The HRV was analysed by linear and non-linear methods. The current level of pain, the tender points, the pressure pain threshold and the impact of FMS on quality of life were assessed. The FMS patients presented higher cardiac sympathetic modulation, lower vagal modulation and lower complexity of HRV in supine position than the HC. Only the HC decreased the complexity indices of HRV during orthostatic stimulus. After a 16-week hydrotherapy programme, the FMS patients increased aerobic capacity, decreased cardiac sympathetic modulation and increased vagal modulation and complexity dynamics of HRV in supine. The FMS patients also improved their cardiac autonomic adjustments to the orthostatic stimulus. Associations between improvements in non-linear dynamics of HRV and improvements in pain and in the impact of FMS on quality of life were found. A 16-week hydrotherapy programme proved to be effective in ameliorating symptoms, aerobic functional capacity and cardiac autonomic control in FMS patients. Improvements in the non-linear dynamics of HRV were related to improvements in pain and in the impact of FMS on quality of life.

VERSATILE, HIGH-RESOLUTION ANTEROGRADE LABELING OF VAGAL EFFERENT PROJECTIONS WITH DEXTRAN AMINES

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Walter, Gary C.; Phillips, Robert J.; Baronowsky, Elizabeth A.; Powley, Terry L.

2009-01-01

None of the anterograde tracers used to label and investigate vagal preganglionic neurons projecting to the viscera has proved optimal for routine and extensive labeling of autonomic terminal fields. To identify an alternative tracer protocol, the present experiment evaluated whether dextran conjugates, which have produced superior results in the CNS, might yield widespread and effective labeling of long, fine-caliber vagal efferents in the peripheral nervous system. The dextran conjugates that were evaluated proved reliable and versatile for labeling the motor neuron pool in its entirety, for single- and multiple-labeling protocols, for both conventional and confocal fluorescence microscopy, and for permanent labeling protocols for brightfield microscopy of the projections to the gastrointestinal (GI) tract. Using a standard ABC kit followed by visualization with DAB as the chromagen, Golgi-like labeling of the vagal efferent terminal fields in the GI wall was achieved with the biotinylated dextrans. The definition of individual terminal varicosities was so sharp and detailed that it was routinely practical to examine the relationship of putative vagal efferent contacts (by the criteria of high magnification light microscopy) with the dendritic and somatic architecture of counterstained neurons in the myenteric plexus. Overall, dextran conjugates provide high-definition labeling of an extensive vagal motor pool in the GI tract, and offer considerable versatility when multiple-staining protocols are needed to elucidate the complexities of the innervation of the gut. PMID:19056424

Pulmonary vein region ablation in experimental vagal atrial fibrillation: role of pulmonary veins versus autonomic ganglia.

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Lemola, Kristina; Chartier, Denis; Yeh, Yung-Hsin; Dubuc, Marc; Cartier, Raymond; Armour, Andrew; Ting, Michael; Sakabe, Masao; Shiroshita-Takeshita, Akiko; Comtois, Philippe; Nattel, Stanley

2008-01-29

Pulmonary vein (PV) -encircling radiofrequency ablation frequently is effective in vagal atrial fibrillation (AF), and there is evidence that PVs may be particularly prone to cholinergically induced arrhythmia mechanisms. However, PV ablation procedures also can affect intracardiac autonomic ganglia. The present study examined the relative role of PVs versus peri-PV autonomic ganglia in an experimental vagal AF model. Cholinergic AF was studied under carbachol infusion in coronary perfused canine left atrial PV preparations in vitro and with cervical vagal stimulation in vivo. Carbachol caused dose-dependent AF promotion in vitro, which was not affected by excision of all PVs. Sustained AF could be induced easily in all dogs during vagal nerve stimulation in vivo both before and after isolation of all PVs with encircling lesions created by a bipolar radiofrequency ablation clamp device. PV elimination had no effect on atrial effective refractory period or its responses to cholinergic stimulation. Autonomic ganglia were identified by bradycardic and/or tachycardic responses to high-frequency subthreshold local stimulation. Ablation of the autonomic ganglia overlying all PV ostia suppressed the effective refractory period-abbreviating and AF-promoting effects of cervical vagal stimulation, whereas ablation of only left- or right-sided PV ostial ganglia failed to suppress AF. Dominant-frequency analysis suggested that the success of ablation in suppressing vagal AF depended on the elimination of high-frequency driver regions. Intact PVs are not needed for maintenance of experimental cholinergic AF. Ablation of the autonomic ganglia at the base of the PVs suppresses vagal responses and may contribute to the effectiveness of PV-directed ablation procedures in vagal AF.

Localization of mGluR5, GABAB, GABAA, and cannabinoid receptors on the vago-vagal reflex pathway responsible for transient lower esophageal sphincter relaxation in humans: an immunohistochemical study

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Rohof, W. O.; Aronica, E.; Beaumont, H.; Troost, D.; Boeckxstaens, G. E.

2012-01-01

Background Transient lower esophageal sphincter relaxations (TLESRs) are the predominant mechanisms underlying gastro-esophageal reflux. TLESRs are mediated by a vago-vagal reflex, which can be blocked by interaction with metabotropic Glutamate Receptor 5 (mGluR5), ?-aminobutyric acid type B

Vagal activity is quadratically related to prosocial traits, prosocial emotions, and observer perceptions of prosociality.

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Kogan, Aleksandr; Oveis, Christopher; Carr, Evan W; Gruber, June; Mauss, Iris B; Shallcross, Amanda; Impett, Emily A; van der Lowe, Ilmo; Hui, Bryant; Cheng, Cecilia; Keltner, Dacher

2014-12-01

In the present article, we introduce the quadratic vagal activity-prosociality hypothesis, a theoretical framework for understanding the vagus nerve's involvement in prosociality. We argue that vagus nerve activity supports prosocial behavior by regulating physiological systems that enable emotional expression, empathy for others' mental and emotional states, the regulation of one's own distress, and the experience of positive emotions. However, we contend that extremely high levels of vagal activity can be detrimental to prosociality. We present 3 studies providing support for our model, finding consistent evidence of a quadratic relationship between respiratory sinus arrhythmia--the degree to which the vagus nerve modulates the heart rate--and prosociality. Individual differences in vagal activity were quadratically related to prosocial traits (Study 1), prosocial emotions (Study 2), and outside ratings of prosociality by complete strangers (Study 3). Thus, too much or too little vagal activity appears to be detrimental to prosociality. The present article provides the 1st theoretical and empirical account of the nonlinear relationship between vagal activity and prosociality.

HRV based health&sport markers using video from the face.

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Capdevila, Lluis; Moreno, Jordi; Movellan, Javier; Parrado, Eva; Ramos-Castro, Juan

2012-01-01

Heart Rate Variability (HRV) is an indicator of health status in the general population and of adaptation to stress in athletes. In this paper we compare the performance of two systems to measure HRV: (1) A commercial system based on recording the physiological cardiac signal with (2) A computer vision system that uses a standard video images of the face to estimate RR from changes in skin color of the face. We show that the computer vision system performs surprisingly well. It estimates individual RR intervals in a non-invasive manner and with error levels comparable to those achieved by the physiological based system.

The Role of Baseline Vagal Tone in Dealing with a Stressor during Face to Face and Computer-Based Social Interactions.

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Rigoni, Daniele; Morganti, Francesca; Braibanti, Paride

2017-01-01

Facing a stressor involves a cardiac vagal tone response and a feedback effect produced by social interaction in visceral regulation. This study evaluated the contribution of baseline vagal tone and of social engagement system (SES) functioning on the ability to deal with a stressor. Participants ( n = 70) were grouped into a minimized social interaction condition (procedure administered through a PC) and a social interaction condition (procedure administered by an experimenter). The State Trait Anxiety Inventory, the Social Interaction Anxiety Scale, the Emotion Regulation Questionnaire and a debriefing questionnaire were completed by the subjects. The baseline vagal tone was registered during the baseline, stressor and recovery phases. The collected results highlighted a significant effect of the baseline vagal tone on vagal suppression. No effect of minimized vs. social interaction conditions on cardiac vagal tone during stressor and recovery phases was detected. Cardiac vagal tone and the results of the questionnaires appear to be not correlated. The study highlighted the main role of baseline vagal tone on visceral regulation. Some remarks on SES to be deepen in further research were raised.

The Role of Baseline Vagal Tone in Dealing with a Stressor during Face to Face and Computer-Based Social Interactions

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Daniele Rigoni

2017-11-01

Full Text Available Facing a stressor involves a cardiac vagal tone response and a feedback effect produced by social interaction in visceral regulation. This study evaluated the contribution of baseline vagal tone and of social engagement system (SES functioning on the ability to deal with a stressor. Participants (n = 70 were grouped into a minimized social interaction condition (procedure administered through a PC and a social interaction condition (procedure administered by an experimenter. The State Trait Anxiety Inventory, the Social Interaction Anxiety Scale, the Emotion Regulation Questionnaire and a debriefing questionnaire were completed by the subjects. The baseline vagal tone was registered during the baseline, stressor and recovery phases. The collected results highlighted a significant effect of the baseline vagal tone on vagal suppression. No effect of minimized vs. social interaction conditions on cardiac vagal tone during stressor and recovery phases was detected. Cardiac vagal tone and the results of the questionnaires appear to be not correlated. The study highlighted the main role of baseline vagal tone on visceral regulation. Some remarks on SES to be deepen in further research were raised.

Mothers' responses to children's negative emotions and child emotion regulation: the moderating role of vagal suppression.

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Perry, Nicole B; Calkins, Susan D; Nelson, Jackie A; Leerkes, Esther M; Marcovitch, Stuart

2012-07-01

The current study examined the moderating effect of children's cardiac vagal suppression on the association between maternal socialization of negative emotions (supportive and nonsupportive responses) and children's emotion regulation behaviors. One hundred and ninety-seven 4-year-olds and their mothers participated. Mothers reported on their reactions to children's negative emotions and children's regulatory behaviors. Observed distraction, an adaptive self-regulatory strategy, and vagal suppression were assessed during a laboratory task designed to elicit frustration. Results indicated that children's vagal suppression moderated the association between mothers' nonsupportive emotion socialization and children's emotion regulation behaviors such that nonsupportive reactions to negative emotions predicted lower observed distraction and lower reported emotion regulation behaviors when children displayed lower levels of vagal suppression. No interaction was found between supportive maternal emotion socialization and vagal suppression for children's emotion regulation behaviors. Results suggest physiological regulation may serve as a buffer against nonsupportive emotion socialization. Copyright © 2011 Wiley Periodicals, Inc.

Validation and characterization of a novel method for selective vagal deafferentation of the gut.

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Diepenbroek, Charlene; Quinn, Danielle; Stephens, Ricky; Zollinger, Benjamin; Anderson, Seth; Pan, Annabelle; de Lartigue, Guillaume

2017-10-01

There is a lack of tools that selectively target vagal afferent neurons (VAN) innervating the gut. We use saporin (SAP), a potent neurotoxin, conjugated to the gastronintestinal (GI) hormone cholecystokinin (CCK-SAP) injected into the nodose ganglia (NG) of male Wistar rats to specifically ablate GI-VAN. We report that CCK-SAP ablates a subpopulation of VAN in culture. In vivo, CCK-SAP injection into the NG reduces VAN innervating the mucosal and muscular layers of the stomach and small intestine but not the colon, while leaving vagal efferent neurons intact. CCK-SAP abolishes feeding-induced c-Fos in the NTS, as well as satiation by CCK or glucagon like peptide-1 (GLP-1). CCK-SAP in the NG of mice also abolishes CCK-induced satiation. Therefore, we provide multiple lines of evidence that injection of CCK-SAP in NG is a novel selective vagal deafferentation technique of the upper GI tract that works in multiple vertebrate models. This method provides improved tissue specificity and superior separation of afferent and efferent signaling compared with vagotomy, capsaicin, and subdiaphragmatic deafferentation. NEW & NOTEWORTHY We develop a new method that allows targeted lesioning of vagal afferent neurons that innervate the upper GI tract while sparing vagal efferent neurons. This reliable approach provides superior tissue specificity and selectivity for vagal afferent over efferent targeting than traditional approaches. It can be used to address questions about the role of gut to brain signaling in physiological and pathophysiological conditions. Copyright © 2017 the American Physiological Society.

The modulatory effects of noradrenaline on vagal control of heart rate in the dogfish, Squalus acanthias.

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Agnisola, Claudio; Randall, David J; Taylor, Edwin W

2003-01-01

The possible interactions between inhibitory vagal control of the heart and circulating levels of catecholamines in dogfish (Squalus acanthias) were studied using an in situ preparation of the heart, which retained intact its innervation from centrally cut vagus nerves. The response to peripheral vagal stimulation typically consisted of an initial cardiac arrest, followed by an escape beat, leading to renewed beating at a mean heart rate lower than the prestimulation rate (partial recovery). Cessation of vagal stimulation led to a transient increase in heart rate, above the prestimulation rate. This whole response was completely abolished by 10(-4) M atropine (a muscarinic cholinergic antagonist). The degree of vagal inhibition was evaluated in terms of both the initial, maximal cardiac interval and the mean heart rate during partial recovery, both expressed as a percentage of the prestimulation heart rate. The mean prestimulation heart rate of this preparation (36+/-4 beats min(-1)) was not affected by noradrenaline but was significantly reduced by 10(-4) M nadolol (a beta-adrenergic receptor antagonist), suggesting the existence of a resting adrenergic tone arising from endogenous catecholamines. The degree of vagal inhibition of heart rate varied with the rate of stimulation and was increased by the presence of 10(-8) M noradrenaline (the normal in vivo level in routinely active fish), while 10(-7) M noradrenaline (the in vivo level measured in disturbed or deeply hypoxic fish) reduced the cardiac response to vagal stimulation. In the presence of 10(-7) M noradrenaline, 10(-4) M nadolol further reduced the vagal response, while 10(-4) M nadolol + 10(-4) M phentolamine had no effect, indicating a complex interaction between adrenoreceptors, possibly involving presynaptic modulation of vagal inhibition.

Vagal activation by sham feeding improves gastric motility in functional dyspepsia.

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Lunding, J A; Nordström, L M; Haukelid, A-O; Gilja, O H; Berstad, A; Hausken, T

2008-06-01

Antral hypomotility and impaired gastric accommodation in patients with functional dyspepsia have been ascribed to vagal dysfunction. We investigated whether vagal stimulation by sham feeding would improve meal-induced gastric motor function in these patients. Fourteen healthy volunteers and 14 functional dyspepsia patients underwent a drink test twice, once with and once without simultaneous sham feeding. After ingesting 500 mL clear meat soup (20 kcal, 37 degrees C) in 4 min, sham feeding was performed for 10 min by chewing a sugar-containing chewing gum while spitting out saliva. Using two- and three-dimensional ultrasound, antral motility index (contraction amplitude x frequency) and intragastric volumes were estimated. Without sham feeding, functional dyspepsia patients had lower motility index than healthy volunteers (area under curve 8.0 +/- 1.2 vs 4.4 +/- 1.0 min(-1), P = 0.04). In functional dyspepsia patients, but not in healthy volunteers, motility index increased and intragastric volume tended to increase by sham feeding (P = 0.04 and P = 0.06 respectively). The change in motility index was negatively correlated to the change in pain score (r = -0.59, P = 0.007). In functional dyspepsia patients, vagal stimulation by sham feeding improves antral motility in response to a soup meal. The result supports the view that impaired vagal stimulation is implicated in the pathogenesis of gastric motility disturbances in functional dyspepsia.

Parenting Stressors and Young Adolescents’ Depressive Symptoms: Does High Vagal Suppression Offer Protection?

Science.gov (United States)

Fletcher, Anne C.; Buehler, Cheryl; Buchanan, Christy M.; Weymouth, Bridget B.

2017-01-01

Grounded in a dual-risk, biosocial perspective of developmental psychopathology, this study examined the role of higher vagal suppression in providing young adolescents protection from four parenting stressors. It was expected that lower vagal suppression would increase youth vulnerability to the deleterious effects of these parenting stressors. Depressive symptoms were examined as a central marker of socioemotional difficulties during early adolescence. The four parenting stressors examined were interparental hostility, maternal use of harsh discipline, maternal inconsistent discipline, and maternal psychological control. Participants were 68 young adolescents (Grade 6) and their mothers. Greater vagal suppression provided protection (i.e., lower depressive symptoms) from interparental hostility, harsh discipline, and maternal psychological control for boys but not for girls. PMID:27979628

Intraperitoneal injections of low doses of C75 elicit a behaviorally specific and vagal afferent-independent inhibition of eating in rats

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Mansouri, Abdelhak; Aja, Susan; Moran, Timothy H.; Ronnett, Gabriele; Kuhajda, Francis P.; Arnold, Myrtha; Geary, Nori; Langhans, Wolfgang; Leonhardt, Monika

2008-01-01

Central and intraperitoneal C75, an inhibitor of fatty acid synthase and stimulator of carnitine palmitoyl-transferase-1, inhibits eating in mice and rats. Mechanisms involved in feeding inhibition after central C75 have been identified, but little is yet known about how systemic C75 might inhibit eating. One issue is whether intraperitoneal C75 reduces food intake in rats by influencing normal physiological controls of food intake or acts nonselectively, for example by eliciting illness or aversion. Another issue relates to whether intraperitoneal C75 acts centrally or, similar to some other peripheral metabolic controls of eating, activates abdominal vagal afferents to inhibit eating. To further address these questions, we investigated the effects of intraperitoneal C75 on spontaneous meal patterns and the formation of conditioned taste aversion (CTA). We also tested whether the eating inhibitory effect of intraperitoneal C75 is vagally mediated by testing rats after either total subdiaphragmatic vagotomy (TVX) or selective subdiaphragmatic vagal deafferentations (SDA). Intraperitoneal injection of 3.2 and 7.5 mg/kg of C75 significantly reduced food intake 3, 12, and 24 h after injection by reducing the number of meals without affecting meal size, whereas 15 mg/kg of C75 reduced both meal number and meal size. The two smaller doses of C75 failed to induce a CTA, but 15 mg/kg C75 did. The eating inhibitory effect of C75 was not diminished in either TVX or SDA rats. We conclude that intraperitoneal injections of low doses of C75 inhibit eating in a behaviorally specific manner and that this effect does not require abdominal vagal afferents. PMID:18667714

Physical activity as a health factor modifying heart rate variability (HRV

Directory of Open Access Journals (Sweden)

Nowosielska-Swadzba Danuta

2015-03-01

Full Text Available Purpose: The aim of the research was the evaluation of the selected HRV factors of the training volleyball players in two training periods and non-training people. Materials and methods : The study involved 8 leading volleyball players aged 20-23 and 13 non-training persons aged 19-26. The study of the training players was conducted twice: in the pre-competition and in the competition period. The study for the non-training persons was conducted once. The selected factors of the spectral analysis have been evaluated: TP [ms 2], share of LF and HF power [n.u], LF/HF indicator and time analysis factors: RR [ms], HR [1/min], RMSSD [ms]. Results : Statistically significant differences appeared only in the selected time analysis factors (RR, HR, between the group of the training and non-training persons. Other differences in the evaluated parameters were not statistically significant. Conclusions : Physical activity influences on the HRV growth. HRV measurement may serve for the control of the changes taking place in the AUN under the influence of the physical activity.

Breathing frequency-independent effect of Tai Chi Chuan on autonomic modulation.

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Lu, Wan-An; Kuo, Cheng-Deng

2014-04-01

This study investigates the breathing frequency (BF)-independent effect of Tai Chi Chuan (TCC) on autonomic nervous modulation in TCC practitioners. Twenty-five TCC practitioners and 25 sedentary normal controls were recruited. The stationary heart rate variability (HRV) measures of TCC practitioners and controls were compared. The same HRV measures in TCC practitioners and among the controls, TCC practitioners before TCC and TCC practitioners 30 min after TCC were compared. In TCC practitioners, the BF, normalized high-frequency power (nHFP), and normalized very low-frequency power were significantly increased, while the normalized low-frequency power (nLFP) was significantly decreased 30 min after TCC. The BF correlated significantly and negatively with heart rate (HR), nHFP and nLFP, and correlated significantly and positively with mean RR interval (MnRR) before TCC in TCC practitioners. A slower BF is associated with a higher HR, a greater vagal modulation, and a greater combined sympatho-vagal modulation before TCC. To remove the effect of BF on HRV measures, new indices such as HR*BF, nHFP*BF, nLFP*BF, and MnRR/BF were introduced for comparison among the controls, TCC practitioners before TCC, and TCC practitioners 30 min after TCC. Thirty minutes after TCC, the MnRR/BF of TCC practitioner was smaller whereas HR*BF and nHFP*BF were greater than those before TCC. The BF-independent effects of TCC on the autonomic nervous modulation of TCC practitioners are an increase in vagal modulation and HR, and a decrease in mean RR interval. The mechanism underlying the parallel increase in HR and vagal modulation in TCC practitioners is not understood yet at present.

Simultaneous exposure to concentrated ambient particles and acrolein causes cardiac effects mediated by parasympathetic modulation in mice

Science.gov (United States)

This study shows that exposure to CAPs and acrolein causes an increase in HRV that is mediated by the parasympathetic nervous system. Numerous studies show that short-term air pollution exposure modulates heart rate variability (HRV), which is an indicator of autonomic influence...

The effects of chronic consumption of heroin on basal and vagal electrical-stimulated gastric acid and pepsin secretion in rat.

Science.gov (United States)

Rafsanjani, Fatemeh N; Maghouli, Fatemeh; Vahedian, Jalal; Esmaeili, Farzaneh

2004-10-01

Addiction to opium and heroin is not only an important social and individual problem in the world but it also affects the human physiology and multiple systems. The aim of this study is to determine the effects of chronic heroin consumption on basal and vagus electrical-stimulated total gastric acid and pepsin secretion in rats. The study was carried out in the Department of Physiology, Kerman University of Medical Sciences, Iran from August 2002 to June 2003. Both male and female rats weighing 200-250 g were used. Rats received daily doses of heroin intraperitoneally starting from 0.2 mg/kg to 0.1 mg/kg/day up to the maintenance level of 0.7 mg/kg and continued until day 12. After anesthesia, tracheotomy and laparotomy, gastric effluents were collected by washout technique with a 15 minutes interval. The total titrable acid was measured by manual titrator, and the total pepsin content was measured by Anson's method. Vagal electrical stimulation was used to stimulate the secretion of acid and pepsin. Heroin results in a significant decrease in total basal acid and pepsin secretions (4.10 +/- 0.18 mmol/15 minutes versus 2.40 +/- 0.16 mmol/15 minutes for acid, pacid and pepsin secretions in vagotomized condition. Heroin also causes a significant decrease in vagal-electrically stimulated acid and pepsin secretions (14.70 +/- 0.54 mmol/15 minutes versus 4.30 +/- 0.21 mmol/15 minutes for acid, pacid and pepsin secretion, but not in vagotomized condition. Heroin may decrease acid secretion by inhibiting vagal release of acetylcholine within the gastric wall. Other probable mechanisms include: presynaptic inhibition of acetylcholine release or depressing the vagal center, inhibition of pentagastrin induced acid secretion, inhibitory effects via central mechanisms, probably mediated by the opiate receptors. Further studies are needed to recognize the actual mechanism.

A brief review and clinical application of heart rate variability biofeedback in sports, exercise, and rehabilitation medicine.

Science.gov (United States)

Prinsloo, Gabriell E; Rauch, H G Laurie; Derman, Wayne E

2014-05-01

An important component of the effective management of chronic noncommunicable disease is the assessment and management of psychosocial stress. The measurement and modulation of heart rate variability (HRV) may be valuable in this regard. To describe the measurement and physiological control of HRV; to describe the impact of psychosocial stress on cardiovascular disease, metabolic syndrome, and chronic respiratory disease, and the relationship between these diseases and changes in HRV; and to describe the influence of biofeedback and exercise on HRV and the use of HRV biofeedback in the management of chronic disease. The PubMed, Medline, and Embase databases were searched (up to August 2013). Additional articles were obtained from the reference lists of relevant articles and reviews. Articles were individually selected for further review based on the quality and focus of the study, and the population studied. Heart rate variability is reduced in stress and in many chronic diseases, and may even predict the development and prognosis of some diseases. Heart rate variability can be increased with both exercise and biofeedback. Although the research on the effect of exercise is conflicting, there is evidence that aerobic training may increase HRV and cardiac vagal tone both in healthy individuals and in patients with disease. Heart rate variability biofeedback is also an effective method of increasing HRV and cardiac vagal tone, and has been shown to decrease stress and reduce the morbidity and mortality of disease. The assessment and management of psychosocial stress is a challenging but important component of effective comprehensive lifestyle interventions for the management of noncommunicable disease. It is, therefore, important for the sports and exercise physician to have an understanding of the therapeutic use of HRV modulation, both in the reduction of stress and in the management of chronic disease.

The Heart´s rhythm 'n' blues: Sex differences in circadian variation patterns of vagal activity vary by depressive symptoms in predominantly healthy employees.

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Jarczok, Marc N; Aguilar-Raab, Corina; Koenig, Julian; Kaess, Michael; Borniger, Jeremy C; Nelson, Randy J; Hall, Martica; Ditzen, Beate; Thayer, Julian F; Fischer, Joachim E

2018-03-15

Successful regulation of emotional states is positively associated to mental health, while difficulties in regulating emotions are negatively associated to overall mental health and in particular associated with anxiety or depression symptoms. A key structure associated to socio-emotional regulatory processes is the central autonomic network. Activity in this structure is associated to vagal activity can be indexed noninvasively and simply by measures of peripheral cardiac autonomic modulations such as heart rate variability. Vagal activity exhibits a circadian variation pattern, with a maximum during nighttime. Depression is known to affect chronobiology. Also, depressive symptoms are known to be associated with decreased resting state vagal activity, but studies investigating the association between circadian variation pattern of vagal activity and depressive symptoms are scarce. We aim to examine these patterns in association to symptom severity of depression using chronobiologic methods. Data from the Manheim Industrial Cohort Studies (MICS) were used. A total of 3,030 predominantly healthy working adults underwent, among others, ambulatory 24-h hear rate-recordings, detailed health examination and online questionnaires and were available for this analysis. The root mean sum of successive differences (RMSSD) was used as an indicator of vagally mediated heart rate variability. Three individual-level cosine function parameters (MESOR, amplitude, acrophase) were estimated to quantify circadian variation pattern. Multivariate linear regression models including important covariates such as age, sex, and lifestyle factors as well as an interaction effect of sex with depressive symptoms were used to estimate the association of circadian variation pattern of vagal activity with depressive symptoms simultaneously. The analysis sample consisted of 20.2% females and an average age 41 with standard deviation of 11 years. Nonparametric bivariate analysis revealed

Parenting stressors and young adolescents' depressive symptoms: Does high vagal suppression offer protection?

Science.gov (United States)

Fletcher, Anne C; Buehler, Cheryl; Buchanan, Christy M; Weymouth, Bridget B

2017-03-01

Grounded in a dual-risk, biosocial perspective of developmental psychopathology, this study examined the role of higher vagal suppression in providing young adolescents protection from four parenting stressors. It was expected that lower vagal suppression would increase youth vulnerability to the deleterious effects of these parenting stressors. Depressive symptoms were examined as a central marker of socioemotional difficulties during early adolescence. The four parenting stressors examined were interparental hostility, maternal use of harsh discipline, maternal inconsistent discipline, and maternal psychological control. Participants were 68 young adolescents (Grade 6) and their mothers. Greater vagal suppression provided protection (i.e., lower depressive symptoms) from interparental hostility, harsh discipline, and maternal psychological control for boys but not for girls. Copyright © 2016 Elsevier Inc. All rights reserved.

Resting sympatho-vagal balance is related to 10 km running performance in master endurance athletes

Directory of Open Access Journals (Sweden)

Angelo Cataldo

2018-02-01

Full Text Available Relationships between heart rate recovery after exercise (HRR, baseline heart rate variability measures (HRV, and time to perform a 10Km running trial (t10Km were evaluated in "master" athletes of endurance to assess whether the measured indexes may be useful for monitoring the training status of the athletes. Ten “master” athletes of endurance, aged 40-60 years, were recruited. After baseline measures of HRV, the athletes performed a graded maximal test on treadmill and HRR was measured at 1 and 2 minutes from recovery. Subsequently they performed a 10Km running trial and t10Km was related to HRV and HRR indexes. The time to perform a 10Km running trial was significantly correlated with baseline HRV indexes. No correlation was found between t10Km and HRR. Baseline HRV measures, but not HRR, were significantly correlated with the time of performance on 10km running in “master” athletes. The enhanced parasympathetic function at rest appears to be a condition to a better performance on 10km running. HRV can be simple and useful measurements for monitoring the training stratus of athletes and their physical condition in proximity of a competition.

Association between changes in heart rate variability during the anticipation of a stressful situation and the stress-induced cortisol response.

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Pulopulos, Matias M; Vanderhasselt, Marie-Anne; De Raedt, Rudi

2018-08-01

Vagal activity - reflecting the activation of stress regulatory mechanisms and prefrontal cortex activation - is thought to play an inhibitory role in the regulation of the hypothalamus-pituitary-adrenal axis. However, most studies investigating the association between stress-induced changes in heart rate variability (HRV, an index of cardiac vagal tone) and cortisol have shown a non-significant relationship. It has been proposed that physiological changes observed during anticipation of a stressor allow individuals to make behavioral, cognitive, and physiological adjustments that are necessary to deal with the upcoming actual stressor. In this study, in a large sample of 171 healthy adults (96 men and 75 women; mean age = 29.98, SD = 11.07), we investigated whether the cortisol response to a laboratory-based stress task was related to anticipation-induced or stress task-induced changes in HRV. As expected, regression analyses showed that a larger decrease in HRV during the anticipation of a stress task was related to higher stress task-induced cortisol increase, but not cortisol recovery. In line with prior research, the stress task-induced change in HRV was not significantly related to cortisol increase or recovery. Our results show for the first time that anticipatory HRV (reflecting differences in stress regulation and prefrontal activity before the encounter with the stressor) is important to understand the stress-induced cortisol increase. Copyright © 2018 Elsevier Ltd. All rights reserved.

Cardiac Vagal Control and Depressive Symptoms in Response to Negative Emotional Stress.

Science.gov (United States)

Tonhajzerova, I; Visnovcova, Z; Mestanikova, A; Jurko, A; Mestanik, M

We aimed to study complex cardiovagal control using heart rate variability (HRV), linear and nonlinear analyses at rest and during negative emotional stress in healthy students with varying depressive symptoms. ECG recording in 20 students was performed at baseline, negative emotional stress, and recovery period. The HRV parameters evaluated were the following: RR interval, spectral power in high-frequency band (HF-HRV), and symbolic dynamics index 2LV%. The subjects were divided into two groups based on the score of the Beck Depression Inventory (BDI) - normal mood (BDI: 0.6 ± 0.2) and mild mood disturbance (BDI: 14.3 ± 1.4). We found significantly lower logHF-HRV during emotional stress in mild mood disturbance compared with normal mood (p = 0.047). No significant differences were found in the remaining parameters. We conclude that negative emotional stress attenuated the cardiovagal control during mood disturbance, which points to discrete abnormalities in the neurocardiac reflex system associated with depressive symptoms. Hampered cardiovagal control could represent a potential pathomechanism leading to depression-linked cardiovascular complications.

The impact of breathing on HRV measurements: implications for the longitudinal follow-up of athletes.

Science.gov (United States)

Saboul, Damien; Pialoux, Vincent; Hautier, Christophe

2013-01-01

The purpose of the present work was to compare daily variations of heart rate variability (HRV) parameters between controlled breathing (CB) and spontaneous breathing (SB) sessions during a longitudinal follow-up of athletes. HRV measurements were performed daily on 10 healthy male runners for 21 consecutive days. The signals were recorded during two successive randomised 5-minutes sessions. One session was performed in CB and the other in SB. The results showed significant differences between the two respiration methods in the temporal, nonlinear and frequency domains. However, significant correlations were observed between CB and SB (higher than 0.70 for RMSSD and SD1), demonstrating that during a longitudinal follow-up, these markers provide the same HRV variations regardless of breathing pattern. By contrast, independent day-to-day variations were observed with HF and LF/HF frequency markers, indicating no significant relationship between SB and CB data over time. Therefore, we consider that SB and CB may be used for HRV longitudinal follow-ups only for temporal and nonlinear markers. Indeed, the same daily increases and decreases were observed whatever the breathing method employed. Conversely, frequency markers did not provide the same variations between SB and CB and we propose that these indicators are not reliable enough to be used for day-to-day HRV monitoring.

Clonidine, an alpha2-receptor agonist, diminishes GABAergic neurotransmission to cardiac vagal neurons in the nucleus ambiguus.

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Philbin, Kerry E; Bateman, Ryan J; Mendelowitz, David

2010-08-06

In hypertension, there is an autonomic imbalance in which sympathetic activity dominates over parasympathetic control. Parasympathetic activity to the heart originates from cardiac vagal neurons located in the nucleus ambiguus. Presympathetic neurons that project to sympathetic neurons in the spinal cord are located in the ventral brainstem in close proximity to cardiac vagal neurons, and many of these presympathetic neurons are catecholaminergic. In addition to their projection to the spinal cord, many of these presympathetic neurons have axon collaterals that arborize into neighboring cardiorespiratory locations and likely release norepinephrine onto nearby neurons. Activation of alpha(2)-adrenergic receptors in the central nervous system evokes a diverse range of physiological effects, including reducing blood pressure. This study tests whether clonidine, an alpha(2)-adrenergic receptor agonist, alters excitatory glutamatergic, and/or inhibitory GABAergic or glycinergic synaptic neurotransmission to cardiac vagal neurons in the nucleus ambiguus. Cardiac vagal neurons were identified in an in vitro brainstem slice preparation, and synaptic events were recording using whole cell voltage clamp methodologies. Clonidine significantly inhibited GABAergic neurotransmission but had no effect on glycinergic or glutamatergic pathways to cardiac vagal neurons. This diminished inhibitory GABAergic neurotransmission to cardiac vagal neurons would increase parasympathetic activity to the heart, decreasing heart rate and blood pressure. The results presented here provide a cellular substrate for the clinical use of clonidine as a treatment for hypertension as well as a role in alleviating posttraumatic stress disorder by evoking an increase in parasympathetic cardiac vagal activity, and a decrease in heart rate and blood pressure. Copyright 2010 Elsevier B.V. All rights reserved.

Neurotransmission to parasympathetic cardiac vagal neurons in the brain stem is altered with left ventricular hypertrophy-induced heart failure.

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Cauley, Edmund; Wang, Xin; Dyavanapalli, Jhansi; Sun, Ke; Garrott, Kara; Kuzmiak-Glancy, Sarah; Kay, Matthew W; Mendelowitz, David

2015-10-01

Hypertension, cardiac hypertrophy, and heart failure (HF) are widespread and debilitating cardiovascular diseases that affect nearly 23 million people worldwide. A distinctive hallmark of these cardiovascular diseases is autonomic imbalance, with increased sympathetic activity and decreased parasympathetic vagal tone. Recent device-based approaches, such as implantable vagal stimulators that stimulate a multitude of visceral sensory and motor fibers in the vagus nerve, are being evaluated as new therapeutic approaches for these and other diseases. However, little is known about how parasympathetic activity to the heart is altered with these diseases, and this lack of knowledge is an obstacle in the goal of devising selective interventions that can target and selectively restore parasympathetic activity to the heart. To identify the changes that occur within the brain stem to diminish the parasympathetic cardiac activity, left ventricular hypertrophy was elicited in rats by aortic pressure overload using a transaortic constriction approach. Cardiac vagal neurons (CVNs) in the brain stem that generate parasympathetic activity to the heart were identified with a retrograde tracer and studied using patch-clamp electrophysiological recordings in vitro. Animals with left cardiac hypertrophy had diminished excitation of CVNs, which was mediated both by an augmented frequency of spontaneous inhibitory GABAergic neurotransmission (with no alteration of inhibitory glycinergic activity) as well as a diminished amplitude and frequency of excitatory neurotransmission to CVNs. Opportunities to alter these network pathways and neurotransmitter receptors provide future targets of intervention in the goal to restore parasympathetic activity and autonomic balance to the heart in cardiac hypertrophy and other cardiovascular diseases. Copyright © 2015 the American Physiological Society.

Heart-Rate Variability—More than Heart Beats?

Directory of Open Access Journals (Sweden)

Gernot Ernst

2017-09-01

Full Text Available Heart-rate variability (HRV is frequently introduced as mirroring imbalances within the autonomous nerve system. Many investigations are based on the paradigm that increased sympathetic tone is associated with decreased parasympathetic tone and vice versa. But HRV is probably more than an indicator for probable disturbances in the autonomous system. Some perturbations trigger not reciprocal, but parallel changes of vagal and sympathetic nerve activity. HRV has also been considered as a surrogate parameter of the complex interaction between brain and cardiovascular system. Systems biology is an inter-disciplinary field of study focusing on complex interactions within biological systems like the cardiovascular system, with the help of computational models and time series analysis, beyond others. Time series are considered surrogates of the particular system, reflecting robustness or fragility. Increased variability is usually seen as associated with a good health condition, whereas lowered variability might signify pathological changes. This might explain why lower HRV parameters were related to decreased life expectancy in several studies. Newer integrating theories have been proposed. According to them, HRV reflects as much the state of the heart as the state of the brain. The polyvagal theory suggests that the physiological state dictates the range of behavior and psychological experience. Stressful events perpetuate the rhythms of autonomic states, and subsequently, behaviors. Reduced variability will according to this theory not only be a surrogate but represent a fundamental homeostasis mechanism in a pathological state. The neurovisceral integration model proposes that cardiac vagal tone, described in HRV beyond others as HF-index, can mirror the functional balance of the neural networks implicated in emotion–cognition interactions. Both recent models represent a more holistic approach to understanding the significance of HRV.

Heart-Rate Variability-More than Heart Beats?

Science.gov (United States)

Ernst, Gernot

2017-01-01

Heart-rate variability (HRV) is frequently introduced as mirroring imbalances within the autonomous nerve system. Many investigations are based on the paradigm that increased sympathetic tone is associated with decreased parasympathetic tone and vice versa . But HRV is probably more than an indicator for probable disturbances in the autonomous system. Some perturbations trigger not reciprocal, but parallel changes of vagal and sympathetic nerve activity. HRV has also been considered as a surrogate parameter of the complex interaction between brain and cardiovascular system. Systems biology is an inter-disciplinary field of study focusing on complex interactions within biological systems like the cardiovascular system, with the help of computational models and time series analysis, beyond others. Time series are considered surrogates of the particular system, reflecting robustness or fragility. Increased variability is usually seen as associated with a good health condition, whereas lowered variability might signify pathological changes. This might explain why lower HRV parameters were related to decreased life expectancy in several studies. Newer integrating theories have been proposed. According to them, HRV reflects as much the state of the heart as the state of the brain. The polyvagal theory suggests that the physiological state dictates the range of behavior and psychological experience. Stressful events perpetuate the rhythms of autonomic states, and subsequently, behaviors. Reduced variability will according to this theory not only be a surrogate but represent a fundamental homeostasis mechanism in a pathological state. The neurovisceral integration model proposes that cardiac vagal tone, described in HRV beyond others as HF-index, can mirror the functional balance of the neural networks implicated in emotion-cognition interactions. Both recent models represent a more holistic approach to understanding the significance of HRV.

Expression of Sex Steroid Hormone Receptors in Vagal Motor Neurons Innervating the Trachea and Esophagus in Mouse

International Nuclear Information System (INIS)

Mukudai, Shigeyuki; Ichi Matsuda, Ken; Bando, Hideki; Takanami, Keiko; Nishio, Takeshi; Sugiyama, Yoichiro; Hisa, Yasuo; Kawata, Mitsuhiro

2016-01-01

The medullary vagal motor nuclei, the nucleus ambiguus (NA) and dorsal motor nucleus of the vagus (DMV), innervate the respiratory and gastrointestinal tracts. We conducted immunohistochemical analysis of expression of the androgen receptor (AR) and estrogen receptor α (ERα), in relation to innervation of the trachea and esophagus via vagal motor nuclei in mice. AR and ERα were expressed in the rostral NA and in part of the DMV. Tracing experiments using cholera toxin B subunit demonstrated that neurons of vagal motor nuclei that innervate the trachea and esophagus express AR and ERα. There was no difference in expression of sex steroid hormone receptors between trachea- and esophagus-innervating neurons. These results suggest that sex steroid hormones may act on vagal motor nuclei via their receptors, thereby regulating functions of the trachea and esophagus

Neural control of left ventricular contractility in the dog heart: synaptic interactions of negative inotropic vagal preganglionic neurons in the nucleus ambiguus with tyrosine hydroxylase immunoreactive terminals.

Science.gov (United States)

Massari, V J; Dickerson, L W; Gray, A L; Lauenstein, J M; Blinder, K J; Newsome, J T; Rodak, D J; Fleming, T J; Gatti, P J; Gillis, R A

1998-08-17

Recent physiological evidence indicates that vagal postganglionic control of left ventricular contractility is mediated by neurons found in a ventricular epicardial fat pad ganglion. In the dog this region has been referred to as the cranial medial ventricular (CMV) ganglion [J.L. Ardell, Structure and function of mammalian intrinsic cardiac neurons, in: J.A. Armour, J.L. Ardell (Eds.). Neurocardiology, Oxford Univ. Press, New York, 1994, pp. 95-114; B.X. Yuan, J.L. Ardell, D.A. Hopkins, A.M. Losier, J.A. Armour, Gross and microscopic anatomy of the canine intrinsic cardiac nervous system, Anat. Rec., 239 (1994) 75-87]. Since activation of the vagal neuronal input to the CMV ganglion reduces left ventricular contractility without influencing cardiac rate or AV conduction, this ganglion contains a functionally selective pool of negative inotropic parasympathetic postganglionic neurons. In the present report we have defined the light microscopic distribution of preganglionic negative inotropic neurons in the CNS which are retrogradely labeled from the CMV ganglion. Some tissues were also processed for the simultaneous immunocytochemical visualization of tyrosine hydroxylase (TH: a marker for catecholaminergic neurons) and examined with both light microscopic and electron microscopic methods. Histochemically visualized neurons were observed in a long slender column in the ventrolateral nucleus ambiguus (NA-VL). The greatest number of retrogradely labeled neurons were observed just rostral to the level of the area postrema. TH perikarya and dendrites were commonly observed interspersed with vagal motoneurons in the NA-VL. TH nerve terminals formed axo-dendritic synapses upon negative inotropic vagal motoneurons, however the origin of these terminals remains to be determined. We conclude that synaptic interactions exist which would permit the parasympathetic preganglionic vagal control of left ventricular contractility to be modulated monosynaptically by

Low heart rate variability in unemployed men: The possible mediating effects of life satisfaction.

Science.gov (United States)

Jandackova, V K; Jackowska, M

2015-01-01

Unemployment has consistently been associated with increased risk of cardiovascular disease and premature mortality, and impaired autonomic modulation of the heart might be one mechanism partly explaining this. This study examined whether the possible effect of unemployment on cardiac autonomic modulation is in part mediated by lower psychological well-being. The sample comprised of 15 job-seeking men aged 30-49 years matched with 15 employed men on age, type of job, smoking habits, alcohol intake, frequency of physical activity, and body mass index. Heart rate variability (HRV) during a modified orthostatic test was the measure of cardiac autonomic modulation, and life satisfaction was the measure of psychological well-being. Unemployed men had significantly lower overall HRV (p = .040) than controls. This association was partially mediated through lower general life satisfaction, and in particular, by low financial satisfaction, independently of demographic and/or behavioral factors that influence HRV. These findings suggest that seeking a job is a potential stressor that may reduce overall HRV and contribute towards disturbance of cardiac autonomic modulation in men. Financial difficulties could be one mechanism through which the effects of unemployment are translated into impaired autonomic modulation.

Effects of vasoactive intestinal polypeptide on heart rate in relation to vagal cardioacceleration in conscious dogs

NARCIS (Netherlands)

Roossien, A; Brunstig, J.R; Nijmeijer, A; Zaagsma, Hans; Zijlstra, W.G

Objective: The vagal cardiac accelerator (VCA) system takes part in the nervous control of the heart rate. In the present study we tried to adduce evidence that vasoactive intestinal polypeptide (VLP) contributes to vagally induced cardioacceleration. Methods: The effect of VIP on heart rate and

Promising effects of xanthine oxidase inhibition by allopurinol on autonomic heart regulation estimated by heart rate variability (HRV) analysis in rats exposed to hypoxia and hyperoxia

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Ziółkowski, Wiesław; Badtke, Piotr; Zajączkowski, Miłosz A.; Flis, Damian J.; Figarski, Adam; Smolińska-Bylańska, Maria; Wierzba, Tomasz H.

2018-01-01

peroxidase (GPx) were measures in erythrocyte lysates. Results Allopurinol reduced oxidative stress which was the result of hypoxia/hyperoxia, as shown by decreased 8-isoprostane plasma concentration. XO inhibition did not markedly influence HRV parameters in standard normoxia. However, during hypoxia, as well as hyperoxia, allopurinol administration resulted in a significant increase of autonomic control upon the heart as shown by increased SDNN and TSP, with an increased vagal contribution (increased rMSSD and HF), whereas sympathovagal indexes (LF/HF, SDNN/rMSSD) remained unchanged. Conclusions Observed regulatory effects of XO inhibition did not confirm preliminary hypothesis which suggested that an antioxidant such as allopurinol might activate chemoreflex resulting in augmented sympathetic discharge to the heart. The HRV regulatory profile of XO inhibition observed during hypoxia as well as post-hypoxic hyperoxia corresponds to reported reduced risk of sudden cardiovascular events. Therefore our data provide a new argument for therapeutical use of allopurinol in hypoxic conditions. PMID:29432445

Promising effects of xanthine oxidase inhibition by allopurinol on autonomic heart regulation estimated by heart rate variability (HRV analysis in rats exposed to hypoxia and hyperoxia.

Directory of Open Access Journals (Sweden)

Stanisław Zajączkowski

lysates.Allopurinol reduced oxidative stress which was the result of hypoxia/hyperoxia, as shown by decreased 8-isoprostane plasma concentration. XO inhibition did not markedly influence HRV parameters in standard normoxia. However, during hypoxia, as well as hyperoxia, allopurinol administration resulted in a significant increase of autonomic control upon the heart as shown by increased SDNN and TSP, with an increased vagal contribution (increased rMSSD and HF, whereas sympathovagal indexes (LF/HF, SDNN/rMSSD remained unchanged.Observed regulatory effects of XO inhibition did not confirm preliminary hypothesis which suggested that an antioxidant such as allopurinol might activate chemoreflex resulting in augmented sympathetic discharge to the heart. The HRV regulatory profile of XO inhibition observed during hypoxia as well as post-hypoxic hyperoxia corresponds to reported reduced risk of sudden cardiovascular events. Therefore our data provide a new argument for therapeutical use of allopurinol in hypoxic conditions.

Malignant Transformation of Vagal Nerve Schwannoma in to ...

African Journals Online (AJOL)

Vagal schwannomas are benign, rare peripheral nerve sheath tumors in the head and neck region. Some physicians opt to closely observe cases of schwannoma of the neck on an outpatient basis rather than to perform radical surgery. However, there is a possibility, albeit rare, of malignant transformation of a.

Physiologic and laboratory correlates of depression, anxiety, and poor sleep in liver cirrhosis

Directory of Open Access Journals (Sweden)

Ko Fang-Yuan

2013-01-01

Full Text Available Abstract Background Studies have shown psychological distress in patients with cirrhosis, yet no studies have evaluated the laboratory and physiologic correlates of psychological symptoms in cirrhosis. This study therefore measured both biochemistry data and heart rate variability (HRV analyses, and aimed to identify the physiologic correlates of depression, anxiety, and poor sleep in cirrhosis. Methods A total of 125 patients with cirrhosis and 55 healthy subjects were recruited. Each subject was assessed through routine biochemistry, 5-minutes ECG monitoring, and psychological ratings of depression, anxiety, and sleep. HRV analysis were used to evaluate autonomic functions. The relationship between depression, sleep, and physiologic correlates was assessed using a multiple regression analysis and stepwise method, controlling for age, duration of illness, and severity of cirrhosis. Results Reduced vagal-related HRV was found in patients with severe liver cirrhosis. Severity of cirrhosis measured by the Child-Pugh score was not correlated with depression or anxiety, and only had a weak correlation with poor sleep. The psychological distress in cirrhosis such as depression, anxiety, and insomnia were correlated specifically to increased levels of aspartate aminotransferase (AST, increased ratios of low frequency to high frequency power, or reduced nonlinear properties of HRV (α1 exponent of detrended fluctuation analysis. Conclusions Increased serum AST and abnormal autonomic nervous activities by HRV analysis were associated with psychological distress in cirrhosis. Because AST is an important mediator of inflammatory process, further research is needed to delineate the role of inflammation in the cirrhosis comorbid with depression.

Peakonsul Jaanus Kirikmäe andis teenetemärgi praost Thomas Vagale / Airi Vaga ; foto: Harold Karu

Index Scriptorium Estoniae

Vaga, Airi, 1940-

2008-01-01

President Toomas Hendrik Ilves annetas iseseisvuspäeva puhul USA I praostkonna praostile Thomas Vagale Valgetähe IV klassi teenetemärgi. Teenetemärgi andis Thomas Vagale üle Eesti Vabariigi peakonsul Jaanus Kirikmäe

The role of heart rate variability in sports physiology.

Science.gov (United States)

Dong, Jin-Guo

2016-05-01

Heart rate variability (HRV) is a relevant marker reflecting cardiac modulation by sympathetic and vagal components of the autonomic nervous system (ANS). Although the clinical application of HRV is mainly associated with the prediction of sudden cardiac death and assessing cardiovascular and metabolic illness progression, recent observations have suggested its applicability to physical exercise training. HRV is becoming one of the most useful tools for tracking the time course of training adaptation/maladaptation of athletes and in setting the optimal training loads leading to improved performances. However, little is known regarding the role of HRV and the internal effects of physical exercise on an athlete, which may be useful in designing fitness programs ensuring sufficient training load that may correspond with the specific ability of the athlete. In this review, we offer a comprehensive assessment of investigations concerning the interrelation between HRV and ANS, and examine how the application of HRV to physical exercise may play a role in sports physiology.

Association of plasma IL-6 and Hsp70 with HRV at different levels of PAHs metabolites.

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Jian Ye

Full Text Available Exposure to polycyclic aromatic hydrocarbons (PAHs is associated with reduced heart rate variability (HRV, a strong predictor of cardiovascular diseases, but the mechanism is not well understood.We hypothesized that PAHs might induce systemic inflammation and stress response, contributing to altered cardiac autonomic function.HRV indices were measured using a 3-channel digital Holter monitor in 800 coke oven workers. Plasma levels of interleukin-6 (IL-6 and heat shock protein 70 (Hsp70 were determined using ELISA. Twelve urinary PAHs metabolites (OH-PAHs were measured by gas chromatography-mass spectrometry.We found that significant dose-dependent relationships between four urinary OH-PAHs and IL-6 (all Ptrend<0.05; and an increase in quartiles of IL-6 was significantly associated with a decrease in total power (TP and low frequency (LF (Ptrend = 0.014 and 0.006, respectively. In particular, elevated IL-6 was associated in a dose-dependent manner with decreased TP and LF in the high-PAHs metabolites groups (all Ptrend<0.05, but not in the low-PAHs metabolites groups. No significant association between Hsp70 and HRV in total population was found after multivariate adjustment. However, increased Hsp70 was significantly associated with elevated standard deviation of NN intervals (SDNN, TP and LF in the low-PAHs metabolites groups (all Ptrend<0.05. We also observed that both IL-6 and Hsp70 significantly interacted with multiple PAHs metabolites in relation to HRV.In coke oven workers, increased IL-6 was associated with a dose-response decreased HRV in the high-PAHs metabolites groups, whereas increase of Hsp70 can result in significant dose-related increase in HRV in the low-PAHs metabolites groups.

Heart rate variability parameters do not correlate with pain intensity in healthy volunteers

NARCIS (Netherlands)

Meeuse, Jan J; Löwik, Marco S P; Löwik, Sabine A M; Aarden, Eline; van Roon, Arie M; Gans, Reinold O B; van Wijhe, Marten; Lefrandt, Joop D; Reyners, Anna K L

OBJECTIVE: When patients cannot indicate pain, physiological parameters may be useful. We tested whether heart rate variability (HRV) parameters, as reflection of sympathetic and vagal tone, can be used to quantify pain intensity. DESIGN: Prospective study. SUBJECTS AND SETTING: A standardized heat

A Pilot Study on Measuring the Readers’ Emotions Using HRV Biofeedback at University Malaysia Pahang

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Iftikhar Yousaf

2016-11-01

Full Text Available Positive associations have been found between reading and emotions. Various techniques, including traditional as well as modern, have been used to measure emotions in the previous studies. However, emotional measurement of the readers of a literary piece through HRV Biofeedback has never been investigated. A study was undertaken to assess whether Heart Rate Variability (HRV biofeedback regarding  measurement of emotions in the readers of English Literature is likely to be effective or not for the first time at University Malaysia Pahang. In this study two scripts of the plays “Dr. Faustus” and “Waiting for Godot” were used. The Scripts were prepared from the Original Texts of these two plays, which might convey the overall message of the plays to the readers and resultantly produce the desired effect on the readers’ emotions. The total words of these two scripts were around 1050 each, allowing the students to complete one script in 7-8 minutes. Six subjects were selected randomly. While they were sitting calm and quiet at the desk, photoplethysmograph sensor was attached to their one of the earlobes which was connected to the emWave Desktop-PC software to record their Baseline HRV. The subjects, one at a time, read the Script 1 “Waiting for Godot” silently. After completion of the reading of Script 1, the emWave software was stopped and the HRV of the subject was recorded and saved automatically in the computer. The same process was repeated with Script 2 “Dr. Faustus”. In this way, emWave software recorded three HRV data for every subject. Results show obvious changes and significant correlations in the HRV of the participants while reading both the scripts. VLF increased for Script 1 while it decreased for Script 2. On the other hand, HF increased for Script 1 and further increased for Script 2.  LF decreased for Script 1 and increased for Script 2. These results point out the tendency that the stress level of the

Cardiac vagal tone, a non-invasive measure of parasympathetic tone, is a clinically relevant tool in Type 1 diabetes mellitus

DEFF Research Database (Denmark)

Brock, C; Jessen, N; Brock, B

2017-01-01

AIMS: To compare a novel index of parasympathetic tone, cardiac vagal tone, with established autonomic variables and to test the hypotheses that (1) cardiac vagal tone would be associated with established time and frequency domain measures of heart rate and (2) cardiac vagal tone would be lower...... identification of people with Type 1 diabetes who should undergo formal autonomic function testing....

Dexmedetomidine decreases inhibitory but not excitatory neurotransmission to cardiac vagal neurons in the nucleus ambiguus.

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Sharp, Douglas B; Wang, Xin; Mendelowitz, David

2014-07-29

Dexmedetomidine, an α2 adrenergic agonist, is a useful sedative but can also cause significant bradycardia. This decrease in heart rate may be due to decreased central sympathetic output as well as increased parasympathetic output from brainstem cardiac vagal neurons. In this study, using whole cell voltage clamp methodology, the actions of dexmedetomidine on excitatory glutamatergic and inhibitory GABAergic and glycinergic neurotransmission to parasympathetic cardiac vagal neurons in the rat nucleus ambiguus was determined. The results indicate that dexmedetomidine decreases both GABAergic and glycinergic inhibitory input to cardiac vagal neurons, with no significant effect on excitatory input. These results provide a mechanism for dexmedetomidine induced bradycardia and has implications for the management of this potentially harmful side effect. Copyright © 2014 Elsevier B.V. All rights reserved.

Search for HRV-parameters that detect a sympathetic shift in heart failure patients on beta-blocker treatment

NARCIS (Netherlands)

Zhang, Yanru; de Peuter, Olav R.; Kamphuisen, Pieter W.; Karemaker, John M.

2013-01-01

Background: A sympathetic shift in heart rate variability (HRV) from high to lower frequencies may be an early signal of deterioration in a monitored patient. Most chronic heart failure (CHF) patients receive (3-blockers. This tends to obscure HRV observation by increasing the fast variations. We

Creating historical range of variation (HRV) time series using landscape modeling: Overview and issues [Chapter 8

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Robert E. Keane

2012-01-01

Simulation modeling can be a powerful tool for generating information about historical range of variation (HRV) in landscape conditions. In this chapter, I will discuss several aspects of the use of simulation modeling to generate landscape HRV data, including (1) the advantages and disadvantages of using simulation, (2) a brief review of possible landscape models. and...

Influence of heart rate in nonlinear HRV indices as a sampling rate effect evaluated on supine and standing

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Juan Bolea

2016-11-01

Full Text Available The purpose of this study is to characterize and attenuate the influence of mean heart rate (HR on nonlinear heart rate variability (HRV indices (correlation dimension, sample and approximate entropy as a consequence of being the HR the intrinsic sampling rate of HRV signal. This influence can notably alter nonlinear HRV indices and lead to biased information regarding autonomic nervous system (ANS modulation.First, a simulation study was carried out to characterize the dependence of nonlinear HRV indices on HR assuming similar ANS modulation. Second, two HR-correction approaches were proposed: one based on regression formulas and another one based on interpolating RR time series. Finally, standard and HR-corrected HRV indices were studied in a body position change database.The simulation study showed the HR-dependence of non-linear indices as a sampling rate effect, as well as the ability of the proposed HR-corrections to attenuate mean HR influence. Analysis in a body position changes database shows that correlation dimension was reduced around 21% in median values in standing with respect to supine position (p < 0.05, concomitant with a 28% increase in mean HR (p < 0.05. After HR-correction, correlation dimension decreased around 18% in standing with respect to supine position, being the decrease still significant. Sample and approximate entropy showed similar trends.HR-corrected nonlinear HRV indices could represent an improvement in their applicability as markers of ANS modulation when mean HR changes.

Heart Rate Variability Analysis in Revascularized Individuals Submitted to an Anaerobic Potency Test

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Geraldo Mendes Gutian Jr

2007-10-01

Full Text Available The objective of this study was to analyze the behavior of autonomic modulation before, during and after the Modified Wingate Test (WanMT, through the analysis of Heart Rate Variability (HRV. Six volunteers between the ages of 40 and 70, post-revascularization procedures (angioplasty and/or surgery, mean duration 10 months, were submitted to supervised training for at least 10 to 14 months. The following protocol, divided into 5 phases, was used: 1 Rest Phase (RP: 180 seconds; 2 Submaximum Phase (SP: 30 seconds; 3 Maximum Phase (MP: 30 seconds; 4 Active Recuperation Phase (ARP; 120 seconds and; 5 Passive Recuperation Phase (PRP: 180 seconds. For the WanMT Test, we selected the load of 3.75% of corporal weight for all volunteers. To analyze the HRV, we used the following parameters: the interval RRr, MNN, SDNN, RMSSD and PNN50. We only observed results for the group according to RMSSD parameters during the rest phase of the test protocol in which the group remained in vagal presence and during all other phases in vagal depression. However, when we analyzed the PNN50, we observed that the group was in medium vagal presence during all of the phases of the test though there was no statistically significant difference (p> 0.05 between the phases. Therefore, we can say that all of the individuals had a similar profile in the autonomic response to the WanMT, confirmed by the parameters studied in the analysis of the HRV in the time domain.

Vagal withdrawal during endoscopic retrograde cholangiopancreatography

DEFF Research Database (Denmark)

Christensen, M; Rasmussen, Verner; Schulze, S

2000-01-01

BACKGROUND: Patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) are at risk of developing cardiorespiratory complications, but the mechanism is still unknown. Treatment with metoprolol 2 h before the endoscopy has been shown to decrease the incidence of myocardial ischaemia......: The existence of a defence-like reaction ('vagal withdrawal') during ERCP has been shown. Metoprolol given 2 h before the procedure did not affect the occurrence of this phenomenon. The interaction of other periendoscopic factors is still unclear and should be studied further....

Low Vagal Tone Magnifies the Association Between Psychosocial Stress Exposure and Internalizing Psychopathology in Adolescents

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McLaughlin, Katie A.; Rith-Najarian, Leslie; Dirks, Melanie A.; Sheridan, Margaret A.

2014-01-01

Vagal tone is a measure of cardiovascular function that facilitates adaptive responses to environmental challenge. Low vagal tone is associated with poor emotional and attentional regulation in children and has been conceptualized as a marker of sensitivity to stress. We investigated whether the associations of a wide range of psychosocial stressors with internalizing and externalizing psychopathology were magnified in adolescents with low vagal tone. Resting heart period data were collected from a diverse community sample of adolescents (ages 13–17; N =168). Adolescents completed measures assessing internalizing and externalizing psychopathology and exposure to stressors occurring in family, peer, and community contexts. Respiratory sinus arrhythmia (RSA) was calculated from the interbeat interval time series. We estimated interactions between RSA and stress exposure in predicting internalizing and externalizing symptoms and evaluated whether interactions differed by gender. Exposure to psychosocial stressors was associated strongly with psychopathology. RSA was unrelated to internalizing or externalizing problems. Significant interactions were observed between RSA and child abuse, community violence, peer victimization, and traumatic events in predicting internalizing but not externalizing symptoms. Stressors were positively associated with internalizing symptoms in adolescents with low RSA but not in those with high RSA. Similar patterns were observed for anxiety and depression. These interactions were more consistently observed for male than female individuals. Low vagal tone is associated with internalizing psychopathology in adolescents exposed to high levels of stressors. Measurement of vagal tone in clinical settings might provide useful information about sensitivity to stress in child and adolescent clients. PMID:24156380

Geometric Accuracy Investigations of SEVIRI High Resolution Visible (HRV Level 1.5 Imagery

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Sultan Kocaman Aksakal

2013-05-01

Full Text Available GCOS (Global Climate Observing System is a long-term program for monitoring the climate, detecting the changes, and assessing their impacts. Remote sensing techniques are being increasingly used for climate-related measurements. Imagery of the SEVIRI instrument on board of the European geostationary satellites Meteosat-8 and Meteosat-9 are often used for the estimation of essential climate variables. In a joint project between the Swiss GCOS Office and ETH Zurich, geometric accuracy and temporal stability of 1-km resolution HRV channel imagery of SEVIRI have been evaluated over Switzerland. A set of tools and algorithms has been developed for the investigations. Statistical analysis and blunder detection have been integrated in the process for robust evaluation. The relative accuracy is evaluated by tracking large numbers of feature points in consecutive HRV images taken at 15-minute intervals. For the absolute accuracy evaluation, lakes in Switzerland and surroundings are used as reference. 20 lakes digitized from Landsat orthophotos are transformed into HRV images and matched via 2D translation terms at sub-pixel level. The algorithms are tested using HRV images taken on 24 days in 2008 (2 days per month. The results show that 2D shifts that are up to 8 pixels are present both in relative and absolute terms.

A model-based approach for the evaluation of vagal and sympathetic activities in a newborn lamb.

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Le Rolle, Virginie; Ojeda, David; Beuchée, Alain; Praud, Jean-Paul; Pladys, Patrick; Hernández, Alfredo I

2013-01-01

This paper proposes a baroreflex model and a recursive identification method to estimate the time-varying vagal and sympathetic contributions to heart rate variability during autonomic maneuvers. The baroreflex model includes baroreceptors, cardiovascular control center, parasympathetic and sympathetic pathways. The gains of the global afferent sympathetic and vagal pathways are identified recursively. The method has been validated on data from newborn lambs, which have been acquired during the application of an autonomic maneuver, without medication and under beta-blockers. Results show a close match between experimental and simulated signals under both conditions. The vagal and sympathetic contributions have been simulated and, as expected, it is possible to observe different baroreflex responses under beta-blockers compared to baseline conditions.

Interferon lambda 1-3 expression in infants hospitalized for RSV or HRV associated bronchiolitis.

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Selvaggi, Carla; Pierangeli, Alessandra; Fabiani, Marco; Spano, Lucia; Nicolai, Ambra; Papoff, Paola; Moretti, Corrado; Midulla, Fabio; Antonelli, Guido; Scagnolari, Carolina

2014-05-01

The airway expression of type III interferons (IFNs) was evaluated in infants hospitalized for respiratory syncytial virus (RSV) or rhinovirus (HRV) bronchiolitis. As an additional objective we sought to determine whether a different expression of IFN lambda 1-3 was associated with different harboring viruses, the clinical course of bronchiolitis or with the levels of well established IFN stimulated genes (ISGs), such as mixovirus resistance A (MxA) and ISG56. The analysis was undertaken in 118 infants with RSV or HRV bronchiolitis. Nasopharyngeal washes were collected for virological studies and molecular analysis of type III IFN responses. RSV elicited higher levels of IFN lambda subtypes when compared with HRV. A similar expression of type III IFN was found in RSVA or RSVB infected infants and in those infected with HRVA or HRVC viruses. Results also indicate that IFN lambda 1 and IFN lambda 2-3 levels were correlated with each other and with MxA and ISG56-mRNAs. In addition, a positive correlation exists between the IFN lambda1 levels and the clinical score index during RSV infection. In particular, higher IFN lambda 1 levels are associated to an increase of respiratory rate. These findings show that differences in the IFN lambda 1-3 levels in infants with RSV or HRV infections are present and that the expression of IFN lambda 1 correlates with the severity of RSV bronchiolitis. Copyright © 2014 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Sensory trigeminal ULF-TENS stimulation reduces HRV response to experimentally induced arithmetic stress: A randomized clinical trial.

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Monaco, Annalisa; Cattaneo, Ruggero; Ortu, Eleonora; Constantinescu, Marian Vladimir; Pietropaoli, Davide

2017-05-01

Ultra Low Frequency Transcutaneous Electric Nervous Stimulation (ULF-TENS) is extensively used for pain relief and for the diagnosis and treatment of temporomandibular disorders (TMD). In addition to its local effects, ULF-TENS acts on the autonomic nervous system (ANS), with particular reference to the periaqueductal gray (PAG), promoting the release of endogenous opioids and modulating descending pain systems. It has been suggested that the PAG participates in the coupling between the emotional stimulus and the appropriate behavioral autonomic response. This function is successfully investigated by HRV. Therefore, our goal is to investigate the effects of trigeminal ULF-TENS stimulation on autonomic behavior in terms of HRV and respiratory parameters during an experimentally-induced arithmetic stress test in healthy subjects. Thirty healthy women between 25 and 35years of age were enrolled and randomly assigned to either the control (TENS stimulation off) or test group (TENS stimulation on). Heart (HR, LF, HF, LF/HF ratio, DET, RMSSD, PNN50, RR) and respiratory (BR) rate were evaluated under basal, T1 (TENS off/on), and stress (mathematical task) conditions. Results showed that HRV parameters and BR significantly changed during the arithmetic stress paradigm (pTENS and control group could be discriminated only by non-linear HRV data, namely RR and DET (p=0.038 and p=0.027, respectively). During the arithmetic task, LF/HF ratio was the most sensitive parameter to discriminate between groups (p=0.019). Our data suggest that trigeminal sensory ULF-TENS reduces the autonomic response in terms of HRV and BR during acute mental stress in healthy subjects. Future directions of our work aim at applying the HRV and BR analysis, with and without TENS stimulation, to individuals with dysfunctional ANS among those with TMD. Copyright © 2017 Elsevier Inc. All rights reserved.

β adrenergic receptor modulation of neurotransmission to cardiac vagal neurons in the nucleus ambiguus.

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Bateman, R J; Boychuk, C R; Philbin, K E; Mendelowitz, D

2012-05-17

β-adrenergic receptors are a class of G protein-coupled receptors that have essential roles in regulating heart rate, blood pressure, and other cardiorespiratory functions. Although the role of β adrenergic receptors in the peripheral nervous system is well characterized, very little is known about their role in the central nervous system despite being localized in many brain regions involved in autonomic activity and regulation. Since parasympathetic activity to the heart is dominated by cardiac vagal neurons (CVNs) originating in the nucleus ambiguus (NA), β adrenergic receptors localized in the NA represent a potential target for modulating cardiac vagal activity and heart rate. This study tests the hypothesis that activation of β adrenergic receptors alters the membrane properties and synaptic neurotransmission to CVNs. CVNs were identified in brainstem slices, and membrane properties and synaptic events were recorded using the whole-cell voltage-clamp technique. The nonselective β agonist isoproterenol significantly decreased inhibitory GABAergic and glycinergic as well as excitatory glutamatergic neurotransmission to CVNs. In addition, the β(1)-selective receptor agonist dobutamine, but not β(2) or β(3) receptor agonists, significantly decreased inhibitory GABAergic and glycinergic and excitatory glutamatergic neurotransmission to CVNs. These decreases in neurotransmission to CVNs persisted in the presence of tetrodotoxin (TTX). These results provide a mechanism by which activation of adrenergic receptors in the brainstem can alter parasympathetic activity to the heart. Likely physiological roles for this adrenergic receptor activation are coordination of parasympathetic-sympathetic activity and β receptor-mediated increases in heart rate upon arousal. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

Cholecystokinin regulates satiation idependently of the abdominal vagal nerve in a pig model of total subdiaphragmatic vagotomy

NARCIS (Netherlands)

Ripken, D.; Wielen, van der N.; Meulen, van der J.; Schuurman, T.; Witkamp, R.F.; Hendriks, H.F.J.; Koopmans, S.J.

2015-01-01

The vagal nerve and gut hormones CCK and GLP-1 play important roles in the control of food intake. However, it is not clear to what extent CCK and GLP-1 increase satiation by stimulating receptors located on abdominal vagal nerve endings or via receptors located elsewhere. This study aimed to

Cholecystokinin regulates satiation independently of the abdominal vagal nerve in a pig model of total subdiaphragmatic vagotomy

NARCIS (Netherlands)

Ripken, D.; Wielen, N. van der; Meulen, J. van der; Schuurman, T.; Witkamp, R.F.; Hendriks, H.F.J.; Koopmans, S.J.

2015-01-01

The vagal nerve and gut hormones CCK and GLP-1 play important roles in the control of food intake. However, it is not clear to what extent CCK and GLP-1 increase satiation by stimulating receptors located on abdominal vagal nerve endings or via receptors located elsewhere. This study aimed to

Indices of heart rate variability as potential early markers of metabolic stress and compromised regulatory capacity in dried-off high-yielding dairy cows.

Science.gov (United States)

Erdmann, S; Mohr, E; Derno, M; Tuchscherer, A; Schäff, C; Börner, S; Kautzsch, U; Kuhla, B; Hammon, H M; Röntgen, M

2017-10-25

High performing dairy cows experience distinct metabolic stress during periods of negative energy balance. Subclinical disorders of the cow's energy metabolism facilitate failure of adaptational responses resulting in health problems and reduced performance. The autonomic nervous system (ANS) with its sympathetic and parasympathetic branches plays a predominant role in adaption to inadequate energy and/or fuel availability and mediation of the stress response. Therefore, we hypothesize that indices of heart rate variability (HRV) that reflect ANS activity and sympatho-vagal balance could be early markers of metabolic stress, and possibly useful to predict cows with compromised regulatory capacity. In this study we analysed the autonomic regulation and stress level of 10 pregnant dried-off German Holstein cows before, during and after a 10-h fasting period by using a wide range of HRV parameters. In addition heat production (HP), energy balance, feed intake, rumen fermentative activity, physical activity, non-esterified fatty acids, β-hydroxybutyric acid, cortisol and total ghrelin plasma concentrations, and body temperature (BT) were measured. In all cows fasting induced immediate regulatory adjustments including increased lipolysis (84%) and total ghrelin levels (179%), reduction of HP (-16%), standing time (-38%) and heart rate (-15%). However, by analysing frequency domain parameters of HRV (high-frequency (HF) and low-frequency (LF) components, ratio LF/HF) cows could be retrospectively assigned to groups reacting to food removal with increased or decreased activity of the parasympathetic branch of the ANS. Regression analysis reveals that under control conditions (feeding ad libitum) group differences were best predicted by the nonlinear domain HRV component Maxline (L MAX, R 2=0.76, threshold; TS=258). Compared with cows having L MAX values above TS (>L MAX: 348±17), those with L MAX values below TS (fasting with a shift of their sympatho-vagal balance

Paroxysmal atrial fibrillation prediction based on HRV analysis and non-dominated sorting genetic algorithm III.

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Boon, K H; Khalil-Hani, M; Malarvili, M B

2018-01-01

This paper presents a method that able to predict the paroxysmal atrial fibrillation (PAF). The method uses shorter heart rate variability (HRV) signals when compared to existing methods, and achieves good prediction accuracy. PAF is a common cardiac arrhythmia that increases the health risk of a patient, and the development of an accurate predictor of the onset of PAF is clinical important because it increases the possibility to electrically stabilize and prevent the onset of atrial arrhythmias with different pacing techniques. We propose a multi-objective optimization algorithm based on the non-dominated sorting genetic algorithm III for optimizing the baseline PAF prediction system, that consists of the stages of pre-processing, HRV feature extraction, and support vector machine (SVM) model. The pre-processing stage comprises of heart rate correction, interpolation, and signal detrending. After that, time-domain, frequency-domain, non-linear HRV features are extracted from the pre-processed data in feature extraction stage. Then, these features are used as input to the SVM for predicting the PAF event. The proposed optimization algorithm is used to optimize the parameters and settings of various HRV feature extraction algorithms, select the best feature subsets, and tune the SVM parameters simultaneously for maximum prediction performance. The proposed method achieves an accuracy rate of 87.7%, which significantly outperforms most of the previous works. This accuracy rate is achieved even with the HRV signal length being reduced from the typical 30 min to just 5 min (a reduction of 83%). Furthermore, another significant result is the sensitivity rate, which is considered more important that other performance metrics in this paper, can be improved with the trade-off of lower specificity. Copyright © 2017 Elsevier B.V. All rights reserved.

Roles for gut vagal sensory signals in determining energy availability and energy expenditure.

Science.gov (United States)

Schwartz, Gary J

2018-08-15

The gut sensory vagus transmits a wide range of meal-related mechanical, chemical and gut peptide signals from gastrointestinal and hepatic tissues to the central nervous system at the level of the caudal brainstem. Results from studies using neurophysiological, behavioral physiological and metabolic approaches that challenge the integrity of this gut-brain axis support an important role for these gut signals in the negative feedback control of energy availability by limiting food intake during a meal. These experimental approaches have now been applied to identify important and unanticipated contributions of the vagal sensory gut-brain axis to the control of two additional effectors of overall energy balance: the feedback control of endogenous energy availability through hepatic glucose production and metabolism, and the control of energy expenditure through brown adipose tissue thermogenesis. Taken together, these studies reveal the pleiotropic influences of gut vagal meal-related signals on energy balance, and encourage experimental efforts aimed at understanding how the brainstem represents, organizes and coordinates gut vagal sensory signals with these three determinants of energy homeostasis. Copyright © 2018 Elsevier B.V. All rights reserved.

Meal parameters and vagal gastrointestinal afferents in mice that experienced early postnatal overnutrition.

Science.gov (United States)

Biddinger, Jessica E; Fox, Edward A

2010-08-04

Early postnatal overnutrition results in a predisposition to develop obesity due in part to hypothalamic and sympathetic dysfunction. Potential involvement of another major regulatory system component--the vagus nerve--has not been examined. Moreover, feeding disturbances have rarely been investigated prior to development of obesity when confounds due to obesity are minimized. To examine these issues, litters were culled on the day of birth to create small litters (SL; overnutrition), or normal size litters (NL; normal nutrition). Body weight, fat pad weight, meal patterns, and vagal sensory duodenal innervation were compared between SL and NL adult mice prior to development of obesity. Meal patterns were studied 18 h/day for 3 weeks using a balanced diet. Then vagal mechanoreceptors were labeled using anterograde transport of wheatgerm agglutinin-horseradish peroxidase injected into the nodose ganglion and their density and morphology were examined. Between postnatal day 1 and weaning, body weight of SL mice was greater than for NL mice. By young adulthood it was similar in both groups, whereas SL fat pad weight was greater in males, suggesting postnatal overnutrition produced a predisposition to obesity. SL mice exhibited increased food intake, decreased satiety ratio, and increased first meal rate (following mild food deprivation) compared to NL mice, suggesting postnatal overnutrition disrupted satiety. The density and structure of intestinal IGLEs appeared similar in SL and NL mice. Thus, although a vagal role cannot be excluded, our meal parameter and anatomical findings provided no evidence for significant postnatal overnutrition effects on vagal gastrointestinal afferents. Copyright 2010 Elsevier Inc. All rights reserved.

The significance of amlodipine on autonomic nervous system adjustment (ANSA method: A new approach in the treatment of hypertension

Directory of Open Access Journals (Sweden)

Milovanović Branislav

2009-01-01

Full Text Available Introduction. Cardiovascular autonomic modulation is altered in patients with essential hypertension. Objective To evaluate acute and long-term effects of amlodipine on cardiovascular autonomic function and haemodynamic status in patients with mild essential hypertension. Methods. Ninety patients (43 male, mean age 52.12 ±10.7 years with mild hypertension were tested before, 30 minutes after the first 5 mg oral dose of amlodipine and three weeks after monotherapy with amlodipine. A comprehensive study protocol was done including finger blood pressure variability (BPV and heart rate variability (HRV beat-to-beat analysis with impedance cardiography, ECG with software short-term HRV and nonlinear analysis, 24-hour Holter ECG monitoring with QT and HRV analysis, 24-hour blood pressure (BP monitoring with systolic and diastolic BPV analysis, cardiovascular autonomic reflex tests, cold pressure test, mental stress test. The patients were also divided into sympathetic and parasympathetic groups, depending on predominance in short time spectral analysis of sympathovagal balance according to low frequency and high frequency values. Results. We confirmed a significant systolic and diastolic BP reduction, and a reduction of pulse pressure during day, night and early morning hours. The reduction of supraventricular and ventricular ectopic beats during the night was also achieved with therapy, but without statistical significance. The increment of sympathetic activity in early phase of amlodipine therapy was without statistical significance and persistence of sympathetic predominance after a few weeks of therapy detected based on the results of short-term spectral HRV analysis. All time domain parameters of long-term HRV analysis were decreased and low frequency amongst spectral parameters. Amlodipne reduced baroreflex sensitivity after three weeks of therapy, but increased it immediately after the administration of the first dose. Conclusion. The results

Less Empathic and More Reactive: The Different Impact of Childhood Maltreatment on Facial Mimicry and Vagal Regulation.

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Martina Ardizzi

Full Text Available Facial mimicry and vagal regulation represent two crucial physiological responses to others' facial expressions of emotions. Facial mimicry, defined as the automatic, rapid and congruent electromyographic activation to others' facial expressions, is implicated in empathy, emotional reciprocity and emotions recognition. Vagal regulation, quantified by the computation of Respiratory Sinus Arrhythmia (RSA, exemplifies the autonomic adaptation to contingent social cues. Although it has been demonstrated that childhood maltreatment induces alterations in the processing of the facial expression of emotions, both at an explicit and implicit level, the effects of maltreatment on children's facial mimicry and vagal regulation in response to facial expressions of emotions remain unknown. The purpose of the present study was to fill this gap, involving 24 street-children (maltreated group and 20 age-matched controls (control group. We recorded their spontaneous facial electromyographic activations of corrugator and zygomaticus muscles and RSA responses during the visualization of the facial expressions of anger, fear, joy and sadness. Results demonstrated a different impact of childhood maltreatment on facial mimicry and vagal regulation. Maltreated children did not show the typical positive-negative modulation of corrugator mimicry. Furthermore, when only negative facial expressions were considered, maltreated children demonstrated lower corrugator mimicry than controls. With respect to vagal regulation, whereas maltreated children manifested the expected and functional inverse correlation between RSA value at rest and RSA response to angry facial expressions, controls did not. These results describe an early and divergent functional adaptation to hostile environment of the two investigated physiological mechanisms. On the one side, maltreatment leads to the suppression of the spontaneous facial mimicry normally concurring to empathic understanding of

Anti-inflammatory effects and mechanisms of vagal nerve stimulation combined with electroacupuncture in a rodent model of TNBS-induced colitis.

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Jin, Haifeng; Guo, Jie; Liu, Jiemin; Lyu, Bin; Foreman, Robert D; Yin, Jieyun; Shi, Zhaohong; Chen, Jiande D Z

2017-09-01

The purpose of this study was to determine the effects and mechanisms of vagal nerve stimulation (VNS) and additive effects of electroacupuncture (EA) on colonic inflammation in a rodent model of IBD. Chronic inflammation in rats was induced by intrarectal TNBS (2,4,6-trinitrobenzenesulfonic acid). The rats were then treated with sham ES (electrical stimulation), VNS, or VNS + EA for 3 wk. Inflammatory responses were assessed by disease activity index (DAI), macroscopic scores and histological scores of colonic tissues, plasma levels of TNFα, IL-1β, and IL-6, and myeloperoxidase (MPO) activity of colonic tissues. The autonomic function was assessed by the spectral analysis of heart rate variability (HRV) derived from the electrocardiogram. It was found that 1 ) the area under curve (AUC) of DAI was substantially decreased with VNS + EA and VNS, with VNS + EA being more effective than VNS ( P < 0.001); 2 ) the macroscopic score was 6.43 ± 0.61 in the sham ES group and reduced to 1.86 ± 0.26 with VNS ( P < 0.001) and 1.29 ± 0.18 with VNS + EA ( P < 0.001); 3 ) the histological score was 4.05 ± 0.58 in the sham ES group and reduced to 1.93 ± 0.37 with VNS ( P < 0.001) and 1.36 ± 0.20 with VNS + EA ( P < 0.001); 4 ) the plasma levels of TNFα, IL-1β, IL-6, and MPO were all significantly decreased with VNS and VNS + EA compared with the sham ES group; and 5 ) autonomically, both VNS + EA and VNS substantially increased vagal activity and decreased sympathetic activity compared with sham EA ( P < 0.001, P < 0.001, respectively). In conclusion, chronic VNS improves inflammation in TNBS-treated rats by inhibiting proinflammatory cytokines via the autonomic mechanism. Addition of noninvasive EA to VNS may enhance the anti-inflammatory effect of VNS. NEW & NOTEWORTHY This is the first study to address and compare the effects of vagal nerve stimulation (VNS), electrical acupuncture (EA) and VNS + EA on TNBS (2,4,6-trinitrobenzenesulfonic acid

Glucagon-like peptide 1 interacts with ghrelin and leptin to regulate glucose metabolism and food intake through vagal afferent neuron signaling.

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Ronveaux, Charlotte C; Tomé, Daniel; Raybould, Helen E

2015-04-01

Emerging evidence has suggested a possible physiologic role for peripheral glucagon-like peptide 1 (GLP-1) in regulating glucose metabolism and food intake. The likely site of action of GLP-1 is on vagal afferent neurons (VANs). The vagal afferent pathway is the major neural pathway by which information about ingested nutrients reaches the central nervous system and influences feeding behavior. Peripheral GLP-1 acts on VANs to inhibit food intake. The mechanism of the GLP-1 receptor (GLP-1R) is unlike other gut-derived receptors; GLP-1Rs change their cellular localization according to feeding status rather than their protein concentrations. It is possible that several gut peptides are involved in mediating GLP-1R translocation. The mechanism of peripheral GLP-1R translocation still needs to be elucidated. We review data supporting the role of peripheral GLP-1 acting on VANs in influencing glucose homeostasis and feeding behavior. We highlight evidence demonstrating that GLP-1 interacts with ghrelin and leptin to induce satiation. Our aim was to understand the mechanism of peripheral GLP-1 in the development of noninvasive antiobesity treatments. © 2015 American Society for Nutrition.

Somatic, Endurance Performance and Heart Rate Variability Profiles of Professional Soccer Players Grouped According to Age

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Botek Michal

2016-12-01

Full Text Available This cross-sectional study compared somatic, endurance performance determinants and heart rate variability (HRV profiles of professional soccer players divided into different age groups: GI (17–19.9 years; n = 23, GII (20–24.9 years; n = 45, GIII (25–29.9 years; n = 30, and GIV (30–39 years; n = 26. Players underwent somatic and HRV assessment and maximal exercise testing. HRV was analyzed by spectral analysis of HRV, and high (HF and low (LF frequency power was transformed by a natural logarithm (Ln. Players in GIV (83 ± 7 kg were heavier (p 25 years showed negligible differences in Pmax unlike the age group differences demonstrated in VO2max. A shift towards relative sympathetic dominance, particularly due to reduced vagal activity, was apparent after approximately 8 years of competing at the professional level.

Resection of cervical vagal schwannoma via a post-auricular approach.

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Roh, Jong-Lyel

2006-03-01

Cervical vagal schwannomas are extremely rare and gross total resection is the standard treatment modality. However, because the conventional cervical approach leaves an incision scar in a visible area, other approaches need to be developed for young women who want the postoperative scar to be invisible. A 28-year-old female underwent complete resection of a 4x4 cm tumor in her right upper neck via a post-auricular approach using an inverted V-shaped incision along the post-auricular sulcus and hairline. The tumor was a schwannoma originating from the right cervical vagus nerve. Postoperatively, right vocal cord paralysis developed despite careful dissection but completely recovered within 6 months after surgery. The patient was satisfied with an invisible external scar which was hidden by her auricle and hair. A cervical vagal schwannoma can be successfully removed by making an incision in a potentially invisible area.

An adaptive technique for multiscale approximate entropy (MAEbin) threshold (r) selection: application to heart rate variability (HRV) and systolic blood pressure variability (SBPV) under postural stress.

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Singh, Amritpal; Saini, Barjinder Singh; Singh, Dilbag

2016-06-01

Multiscale approximate entropy (MAE) is used to quantify the complexity of a time series as a function of time scale τ. Approximate entropy (ApEn) tolerance threshold selection 'r' is based on either: (1) arbitrary selection in the recommended range (0.1-0.25) times standard deviation of time series (2) or finding maximum ApEn (ApEnmax) i.e., the point where self-matches start to prevail over other matches and choosing the corresponding 'r' (rmax) as threshold (3) or computing rchon by empirically finding the relation between rmax, SD1/SD2 ratio and N using curve fitting, where, SD1 and SD2 are short-term and long-term variability of a time series respectively. None of these methods is gold standard for selection of 'r'. In our previous study [1], an adaptive procedure for selection of 'r' is proposed for approximate entropy (ApEn). In this paper, this is extended to multiple time scales using MAEbin and multiscale cross-MAEbin (XMAEbin). We applied this to simulations i.e. 50 realizations (n = 50) of random number series, fractional Brownian motion (fBm) and MIX (P) [1] series of data length of N = 300 and short term recordings of HRV and SBPV performed under postural stress from supine to standing. MAEbin and XMAEbin analysis was performed on laboratory recorded data of 50 healthy young subjects experiencing postural stress from supine to upright. The study showed that (i) ApEnbin of HRV is more than SBPV in supine position but is lower than SBPV in upright position (ii) ApEnbin of HRV decreases from supine i.e. 1.7324 ± 0.112 (mean ± SD) to upright 1.4916 ± 0.108 due to vagal inhibition (iii) ApEnbin of SBPV increases from supine i.e. 1.5535 ± 0.098 to upright i.e. 1.6241 ± 0.101 due sympathetic activation (iv) individual and cross complexities of RRi and systolic blood pressure (SBP) series depend on time scale under consideration (v) XMAEbin calculated using ApEnmax is correlated with cross-MAE calculated using ApEn (0.1-0.26) in steps of 0

Effort reward imbalance is associated with vagal withdrawal in Danish public sector employees

DEFF Research Database (Denmark)

Eller, Nanna Hurwitz; Blønd, Morten; Nielsen, Martin

2011-01-01

The current study analyzed the relationship between psychosocial work environment assessed by the Effort Reward Imbalance Model (ERI-model) and heart rate variability (HRV) measured at baseline and again, two years later, as this relationship is scarcely covered by the literature.......The current study analyzed the relationship between psychosocial work environment assessed by the Effort Reward Imbalance Model (ERI-model) and heart rate variability (HRV) measured at baseline and again, two years later, as this relationship is scarcely covered by the literature....

Determining cardiac vagal threshold from short term heart rate complexity

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Hamdan Rami Abou

2016-09-01

Full Text Available Evaluating individual aerobic exercise capacity is fundamental in sports and exercise medicine but associated with organizational and instrumental effort. Here, we extract an index related to common performance markers, the aerobic and anaerobic thresholds enabling the estimation of exercise capacity from a conventional sports watch supporting beatwise heart rate tracking. Therefore, cardiac vagal threshold (CVT was determined in 19 male subjects performing an incremental maximum exercise test. CVT varied around the anaerobic threshold AnT with mean deviation of 7.9 ± 17.7 W. A high correspondence of the two thresholds was indicated by Bland-Altman plots with limits of agreement −27.5 W and 43.4 W. Additionally, CVT was strongly correlated AnT (rp = 0.86, p < 0.001 and reproduced this marker well (rc = 0.81. We conclude, that cardiac vagal threshold derived from compression entropy time course can be useful to assess physical fitness in an uncomplicated way.

Getting to the Heart of Masculinity Stressors: Masculinity Threats Induce Pronounced Vagal Withdrawal During a Speaking Task.

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Kramer, Brandon L; Himmelstein, Mary S; Springer, Kristen W

2017-12-01

Previous work has found that traditional masculinity ideals and behaviors play a crucial role in higher rates of morbidity and mortality for men. Some studies also suggest that threatening men's masculinity can be stressful. Over time, this stress can weigh on men's cardiovascular and metabolic systems, which may contribute to men's higher rates of cardiometabolic health issues. The purpose of this study is to explore how masculinity threats affect men's heart rate and heart rate variability reactivity (i.e., vagal withdrawal) to masculinity feedback on a social speaking task. Two hundred and eighty-five undergraduate males were randomly assigned to one of six conditions during a laboratory-based speech task. They received one of two feedback types (masculinity or control) and one of three feedback levels (low, high, or dropping) in order to assess whether masculinity threats influence heart rate reactivity and vagal withdrawal patterns during the speech task. Men who receive low masculinity feedback during the speech task experienced more pronounced vagal withdrawal relative to those who received the control. Masculinity threats can induce vagal withdrawal that may accumulate over the life course to contribute to men's relatively worse cardiometabolic health.

Architecture of vagal motor units controlling striated muscle of esophagus: peripheral elements patterning peristalsis?

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Powley, Terry L; Mittal, Ravinder K; Baronowsky, Elizabeth A; Hudson, Cherie N; Martin, Felecia N; McAdams, Jennifer L; Mason, Jacqueline K; Phillips, Robert J

2013-12-01

Little is known about the architecture of the vagal motor units that control esophageal striated muscle, in spite of the fact that these units are necessary, and responsible, for peristalsis. The present experiment was designed to characterize the motor neuron projection fields and terminal arbors forming esophageal motor units. Nucleus ambiguus compact formation neurons of the rat were labeled by bilateral intracranial injections of the anterograde tracer dextran biotin. After tracer transport, thoracic and abdominal esophagi were removed and prepared as whole mounts of muscle wall without mucosa or submucosa. Labeled terminal arbors of individual vagal motor neurons (n=78) in the esophageal wall were inventoried, digitized and analyzed morphometrically. The size of individual vagal motor units innervating striated muscle, throughout thoracic and abdominal esophagus, averaged 52 endplates per motor neuron, a value indicative of fine motor control. A majority (77%) of the motor terminal arbors also issued one or more collateral branches that contacted neurons, including nitric oxide synthase-positive neurons, of local myenteric ganglia. Individual motor neuron terminal arbors co-innervated, or supplied endplates in tandem to, both longitudinal and circular muscle fibers in roughly similar proportions (i.e., two endplates to longitudinal for every three endplates to circular fibers). Both the observation that vagal motor unit collaterals project to myenteric ganglia and the fact that individual motor units co-innervate longitudinal and circular muscle layers are consistent with the hypothesis that elements contributing to peristaltic programming inhere, or are "hardwired," in the peripheral architecture of esophageal motor units. © 2013.

Automatic seizure detection based on the combination of newborn multi-channel EEG and HRV information

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Mesbah, Mostefa; Balakrishnan, Malarvili; Colditz, Paul B.; Boashash, Boualem

2012-12-01

This article proposes a new method for newborn seizure detection that uses information extracted from both multi-channel electroencephalogram (EEG) and a single channel electrocardiogram (ECG). The aim of the study is to assess whether additional information extracted from ECG can improve the performance of seizure detectors based solely on EEG. Two different approaches were used to combine this extracted information. The first approach, known as feature fusion, involves combining features extracted from EEG and heart rate variability (HRV) into a single feature vector prior to feeding it to a classifier. The second approach, called classifier or decision fusion, is achieved by combining the independent decisions of the EEG and the HRV-based classifiers. Tested on recordings obtained from eight newborns with identified EEG seizures, the proposed neonatal seizure detection algorithms achieved 95.20% sensitivity and 88.60% specificity for the feature fusion case and 95.20% sensitivity and 94.30% specificity for the classifier fusion case. These results are considerably better than those involving classifiers using EEG only (80.90%, 86.50%) or HRV only (85.70%, 84.60%).

Diet-driven microbiota dysbiosis is associated with vagal remodeling and obesity.

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Sen, Tanusree; Cawthon, Carolina R; Ihde, Benjamin Thomas; Hajnal, Andras; DiLorenzo, Patricia M; de La Serre, Claire B; Czaja, Krzysztof

2017-05-01

Obesity is one of the major health issues in the United States. Consumption of diets rich in energy, notably from fats and sugars (high-fat/high-sugar diet: HF/HSD) is linked to the development of obesity and a popular dietary approach for weight loss is to reduce fat intake. Obesity research traditionally uses low and high fat diets and there has been limited investigation of the potential detrimental effects of a low-fat/high-sugar diet (LF/HSD) on body fat accumulation and health. Therefore, in the present study, we investigated the effects of HF/HSD and LF/HSD on microbiota composition, gut inflammation, gut-brain vagal communication and body fat accumulation. Specifically, we tested the hypothesis that LF/HSD changes the gut microbiota, induces gut inflammation and alters vagal gut-brain communication, associated with increased body fat accumulation. Sprague-Dawley rats were fed an HF/HSD, LF/HSD or control low-fat/low-sugar diet (LF/LSD) for 4weeks. Body weight, caloric intake, and body composition were monitored daily and fecal samples were collected at baseline, 1, 6 and 27days after the dietary switch. After four weeks, blood and tissues (gut, brain, liver and nodose ganglia) were sampled. Both HF/HSD and LF/HSD-fed rats displayed significant increases in body weight and body fat compared to LF/LSD-fed rats. 16S rRNA sequencing showed that both HF/HSD and LF/HSD-fed animals exhibited gut microbiota dysbiosis characterized by an overall decrease in bacterial diversity and an increase in Firmicutes/Bacteriodetes ratio. Dysbiosis was typified by a bloom in Clostridia and Bacilli and a marked decrease in Lactobacillus spp. LF/HSD-fed animals showed a specific increase in Sutterella and Bilophila, both Proteobacteria, abundances of which have been associated with liver damage. Expression of pro-inflammatory cytokines, such as IL-6, IL-1β and TNFα, was upregulated in the cecum while levels of tight junction protein occludin were downregulated in both HF

Heart rate variability to monitor performance in elite athletes: Criticalities and avoidable pitfalls.

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Lucini, Daniela; Marchetti, Ilaria; Spataro, Antonio; Malacarne, Mara; Benzi, Manuela; Tamorri, Stefano; Sala, Roberto; Pagani, Massimo

2017-08-01

Spectral analysis of Heart Rate Variability (HRV) is a simple, non-invasive technique that is widely used in sport to assess sympatho-vagal regulation of the heart. Its employment is increasing partly due to the rising usage of wearable devices. However data acquisition using these devices may be suboptimal because they cannot discriminate between sinus and non-sinus beats and do not record any data regarding respiratory frequency. This information is mandatory for a correct clinical interpretation. This study involved 974 elite athletes, all of them underwent a complete autonomic assessment, by way of Autoregressive HRV analysis. In 91 subjects (9% of the total population) we observed criticalities of either cardiac rhythm or respiration. Through perusal of one-lead ECG analysis we observed that 77 subjects had atrial or ventricular ectopy, i.e. conditions which impair stationarity and sinus rhythm. Running anyway autonomic nervous system analysis in this population, we observed that RR variance and raw values of LF and HF regions are significantly higher in arrhythmic subjects. In addition 14 subjects had slow (about 6 breath/min, 0.1Hz) respiration. This condition clouds the separation between LF from HF spectral regions of RR interval variability, respectively markers of the prevalent sympathetic and vagal modulation of SA node and of their synergistic interaction. Caution must be payed when assessing HRV with non-ECG wearable devices. Recording ECG signal and ensuring that respiratory rate is higher than 10 breath/min are both prerequisites for a more reliable analysis of HRV particularly in athletes. Copyright © 2017 Elsevier B.V. All rights reserved.

Vagal and sympathetic activity in burnouts during a mentally demanding workday

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Zanstra, Ydwine J.; Schellekens, Jan M. H.; Schaap, Cas; Kooistra, Libbe

2006-01-01

Objective: We study differences in task performance and related sympathetic-vagal reaction patterns between burnouts and controls during a mentally demanding workday. Method: Thirty-nine adults with burnout and 40 healthy controls performed mental tasks during a simulated workday. At pretest, just

Exposure to a high fat diet during the perinatal period alters vagal motoneurone excitability, even in the absence of obesity.

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Bhagat, Ruchi; Fortna, Samuel R; Browning, Kirsteen N

2015-01-01

Obesity is recognized as being multifactorial in origin, involving both genetic and environmental factors. The perinatal period is known to be critically important in the development of neural circuits responsible for energy homeostasis and the integration of autonomic reflexes. Diet-induced obesity alters the biophysical, pharmacological and morphological properties of vagal neurocircuits regulating upper gastrointestinal tract functions, including satiety. Less information is available, however, regarding the effects of a high fat diet (HFD) itself on the properties of vagal neurocircuits. The present study was designed to test the hypothesis that exposure to a HFD during the perinatal period alters the electrophysiological, pharmacological and morphological properties of vagal efferent motoneurones innervating the stomach. Our data indicate that perinatal HFD decreases the excitability of gastric-projecting dorsal motor nucleus neurones and dysregulates neurotransmitter release from synaptic inputs and that these alterations occur prior to the development of obesity. These findings represent the first direct evidence that exposure to a HFD modulates the processing of central vagal neurocircuits even in the absence of obesity. The perinatal period is critically important to the development of autonomic neural circuits responsible for energy homeostasis. Vagal neurocircuits are vital to the regulation of upper gastrointestinal functions, including satiety. Diet-induced obesity modulates the excitability and responsiveness of both peripheral vagal afferents and central vagal efferents but less information is available regarding the effects of diet per se on vagal neurocircuit functions. The aims of this study were to investigate whether perinatal exposure to a high fat diet (HFD) dysregulated dorsal motor nucleus of the vagus (DMV) neurones, prior to the development of obesity. Whole cell patch clamp recordings were made from gastric-projecting DMV neurones in thin

Effects of moderate and heavy endurance exercise on nocturnal HRV.

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Hynynen, E; Vesterinen, V; Rusko, H; Nummela, A

2010-06-01

This study examined the effects of endurance exercise on nocturnal autonomic modulation. Nocturnal R-R intervals were collected after a rest day, after a moderate endurance exercise and after a marathon run in ten healthy, physically active men. Heart rate variability (HRV) was analyzed as a continuous four-hour period starting 30 min after going to bed for sleep. In relation to average nocturnal heart rate after rest day, increases to 109+/-6% and 130+/-11% of baseline were found after moderate endurance exercise and marathon, respectively. Standard deviation of R-R intervals decreased to 90+/-9% and 64+/-10%, root-mean-square of differences between adjacent R-R intervals to 87+/-10% and 55+/-16%, and high frequency power to 77+/-19% and 34+/-19% of baseline after moderate endurance exercise and marathon, respectively. Also nocturnal low frequency power decreased to 56+/-26% of baseline after the marathon. Changes in nocturnal heart rate and HRV suggest prolonged dose-response effects on autonomic modulation after exercises, which may give useful information on the extent of exercise-induced nocturnal autonomic modulation and disturbance to the homeostasis.

Methodological Framework for Estimating the Correlation Dimension in HRV Signals

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Juan Bolea

2014-01-01

Full Text Available This paper presents a methodological framework for robust estimation of the correlation dimension in HRV signals. It includes (i a fast algorithm for on-line computation of correlation sums; (ii log-log curves fitting to a sigmoidal function for robust maximum slope estimation discarding the estimation according to fitting requirements; (iii three different approaches for linear region slope estimation based on latter point; and (iv exponential fitting for robust estimation of saturation level of slope series with increasing embedded dimension to finally obtain the correlation dimension estimate. Each approach for slope estimation leads to a correlation dimension estimate, called D^2, D^2⊥, and D^2max. D^2 and D^2max estimate the theoretical value of correlation dimension for the Lorenz attractor with relative error of 4%, and D^2⊥ with 1%. The three approaches are applied to HRV signals of pregnant women before spinal anesthesia for cesarean delivery in order to identify patients at risk for hypotension. D^2 keeps the 81% of accuracy previously described in the literature while D^2⊥ and D^2max approaches reach 91% of accuracy in the same database.

IN VITRO EXAMINATION OF ONTOGENESIS OF DEVELOPING NEURONAL CELLS IN VAGAL NUCLEI IN MEDULLA OBLONGATA IN NEWBORNS

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Islami, Hilmi; Shabani, Ragip; Bexheti, Sadi; Behluli, Ibrahim; Šukalo, Aziz; Raka, Denis; Koliqi, Rozafa; Haliti, Naim; Dauti, Hilmi; Krasniqi, Shaip; Disha, Mentor

2008-01-01

The development of neuron cells in vagal nerve nuclei in medulla oblongata was studied in vitro in live newborns and stillborns from different cases. Morphological changes were studied in respiratory nuclei of dorsal motor centre (DMNV) and nucleus tractus solitarius (NTS) in medulla oblongata. The material from medulla oblongata was fixated in 10μ buffered formalin solution. Fixated material was cut in series of 10μ thickness, with starting point from obex in ± 4 mm thickness. Special histochemical and histoenzymatic methods for central nervous system were used: cresyl echt violet coloring, tolyidin blue, Sevier-Munger modification and Grimelius coloring. In immature newborns (abortions and immature) in dorsal motor nucleus of the vagus (DMNV) population stages S1, S2, S3 are dominant. In neuron population in vagal sensory nuclei (NTS) stages S1, S2 are dominant. In more advanced stages of development of newborns (premature), in DMNV stages S3 and S4 are seen and in NTS stages S2 and S3 are dominant. In mature phase of newborns (maturity) in vagal nucleus DMNV stages S5 and S6 are dominant, while in sensory nucleus NTS stages S4 and S5 are dominant. These data suggest that neuron population in dorsal motor nucleus of the vagus (DMNV) are more advanced in neuronal maturity in comparison with sensory neuron population of vagal sensory nucleus NTS. This occurrence shows that phylogenetic development of motor complex is more advanced than the sensory one, which is expected to take new information’s from the extra uterine life after birth (extra uterine vagal phenotype) PMID:19125713

Exercise training preserves vagal preganglionic neurones and restores parasympathetic tonus in heart failure.

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Ichige, Marcelo H A; Santos, Carla R; Jordão, Camila P; Ceroni, Alexandre; Negrão, Carlos E; Michelini, Lisete C

2016-11-01

Heart Failure (HF) is accompanied by reduced ventricular function, activation of compensatory neurohormonal mechanisms and marked autonomic dysfunction characterized by exaggerated sympathoexcitation and reduced parasympathetic activity. With 6 weeks of exercise training, HF-related loss of choline acetyltransferase (ChAT)-positive vagal preganglionic neurones is avoided, restoring the parasympathetic tonus to the heart, and the immunoreactivity of dopamine β-hydroxylase-positive premotor neurones that drive sympathetic outflow to the heart is reduced. Training-induced correction of autonomic dysfunction occurs even with the persistence of abnormal ventricular function. Strong positive correlation between improved parasympathetic tonus to the heart and increased ChAT immunoreactivity in vagal preganglionic neurones after training indicates this is a crucial mechanism to restore autonomic function in heart failure. Exercise training is an efficient tool to attenuate sympathoexcitation, a hallmark of heart failure (HF). Although sympathetic modulation in HF is widely studied, information regarding parasympathetic control is lacking. We examined the combined effects of sympathetic and vagal tonus to the heart in sedentary (Sed) and exercise trained (ET) HF rats and the contribution of respective premotor and preganglionic neurones. Wistar rats submitted to coronary artery ligation or sham surgery were assigned to training or sedentary protocols for 6 weeks. After haemodynamic, autonomic tonus (atropine and atenolol i.v.) and ventricular function determinations, brains were collected for immunoreactivity assays (choline acetyltransferase, ChATir; dopamine β-hydroxylase, DBHir) and neuronal counting in the dorsal motor nucleus of vagus (DMV), nucleus ambiguus (NA) and rostroventrolateral medulla (RVLM). HF-Sed vs. SHAM-Sed exhibited decreased exercise capacity, reduced ejection fraction, increased left ventricle end diastolic pressure, smaller positive and negative

Baroreflex deficiency induces additional impairment of vagal tone, diastolic function and calcium handling proteins after myocardial infarction

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Mostarda, Cristiano; Rodrigues, Bruno; Medeiros, Alessandra; Moreira, Edson D; Moraes-Silva, Ivana C; Brum, Patricia C; Angelis, Katia De; Irigoyen, Maria-Cláudia

2014-01-01

Baroreflex dysfunction has been considered an important mortality predictor after myocardial infarction (MI). However, the impact of baroreflex deficiency prior to MI on tonic autonomic control and cardiac function, and on the profile of proteins associated with intracellular calcium handling has not yet been studied. The aim of the present study was to analyze how the impairment of baroreflex induced by sinoaortic denervation (SAD) prior to MI in rats affects the tonic autonomic control, ventricular function and cardiomyocyte calcium handling proteins. After 15 days of following or SAD surgery, rats underwent MI. Echocardiographic, hemodynamic, autonomic and molecular evaluations were performed 90 days after MI. Baroreflex impairment led to additional damage on: left ventricular remodeling, diastolic function, vagal tonus and intrinsic heart rate after MI. The loss of vagal component of the arterial baroreflex and vagal tonus were correlated with changes in the cardiac proteins involved in intracellular calcium homeostasis. Furthermore, additional increase in sodium calcium exchanger expression levels was associated with impaired diastolic function in experimental animals. Our findings strongly suggest that previous arterial baroreflex deficiency may induce additional impairment of vagal tonus, which was associated with calcium handling proteins abnormalities, probably triggering ventricular diastolic dysfunction after MI in rats. PMID:24936224

Clonidine, an α2 receptor agonist, diminishes GABAergic neurotransmission to cardiac vagal neurons in the nucleus ambiguus

OpenAIRE

Philbin, Kerry E.; Bateman, Ryan J.; Mendelowitz, David

2010-01-01

In hypertension there is an autonomic imbalance in which sympathetic activity dominates over parasympathetic control. Parasympathetic activity to the heart originates from cardiac vagal neurons located in the nucleus ambiguus. Pre-sympathetic neurons that project to sympathetic neurons in the spinal cord are located in the ventral brainstem in close proximity to cardiac vagal neurons, and many of these pre-sympathetic neurons are catecholaminergic. In addition to their projection to the spina...

Effect of Head-Down Bed Rest and Artificial Gravity Countermeasure on Cardiac Autonomic and Advanced Electrocardiographic Function

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Schlegel, T. T.; Platts, S.; Stenger, M.; Ribeiro, C.; Natapoff, A.; Howarth, M.; Evans, J.

2007-01-01

To study the effects of 21 days of head-down bed rest (HDBR), with versus without an artificial gravity (AG) countermeasure, on cardiac autonomic and advanced electrocardiographic function. Fourteen healthy men participated in the study: seven experienced 21 days of HDBR alone ("HDBR controls") and seven the same degree and duration of HDBR but with approximately 1hr daily short-arm centrifugation as an AG countermeasure ("AG-treated"). Five minute supine high-fidelity 12-lead ECGs were obtained in all subjects: 1) 4 days before HDBR; 2) on the last day of HDBR; and 3) 7 days after HDBR. Besides conventional 12-lead ECG intervals and voltages, all of the following advanced ECG parameters were studied: 1) both stochastic (time and frequency domain) and deterministic heart rate variability (HRV); 2) beat-to-beat QT interval variability (QTV); 3) T-wave morphology, including signal-averaged T-wave residua (TWR) and principal component analysis ratios; 4) other SAECG-related parameters including high frequency QRS ECG and late potentials; and 5) several advanced ECG estimates of left ventricular (LV) mass. The most important results by repeated measures ANOVA were that: 1) Heart rates, Bazett-corrected QTc intervals, TWR, LF/HF power and the alpha 1 of HRV were significantly increased in both groups (i.e., by HDBR), but with no relevant HDBR*group differences; 2) All purely "vagally-mediated" parameters of HRV (e.g., RMSSD, HF power, Poincare SD1, etc.), PR intervals, and also several parameters of LV mass (Cornell and Sokolow-Lyon voltages, spatial ventricular activation times, ventricular gradients) were all significantly decreased in both groups (i.e., by HDBR), but again with no relevant HDBR*group differences); 3) All "generalized" or "vagal plus sympathetic" parameters of stochastic HRV (i.e., SDNN, total power, LF power) were significantly more decreased in the AG-treated group than in the HDBR-only group (i.e., here there was a relevant HDBR*group difference

Cardiorespiratory interactions previously identified as mammalian are present in the primitive lungfish.

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Monteiro, Diana A; Taylor, Edwin W; Sartori, Marina R; Cruz, André L; Rantin, Francisco T; Leite, Cleo A C

2018-02-01

The present study has revealed that the lungfish has both structural and functional features of its system for physiological control of heart rate, previously considered solely mammalian, that together generate variability (HRV). Ultrastructural and electrophysiological investigation revealed that the nerves connecting the brain to the heart are myelinated, conferring rapid conduction velocities, comparable to mammalian fibers that generate instantaneous changes in heart rate at the onset of each air breath. These respiration-related changes in beat-to-beat cardiac intervals were detected by complex analysis of HRV and shown to maximize oxygen uptake per breath, a causal relationship never conclusively demonstrated in mammals. Cardiac vagal preganglionic neurons, responsible for controlling heart rate via the parasympathetic vagus nerve, were shown to have multiple locations, chiefly within the dorsal vagal motor nucleus that may enable interactive control of the circulatory and respiratory systems, similar to that described for tetrapods. The present illustration of an apparently highly evolved control system for HRV in a fish with a proven ancient lineage, based on paleontological, morphological, and recent genetic evidence, questions much of the anthropocentric thinking implied by some mammalian physiologists and encouraged by many psychobiologists. It is possible that some characteristics of mammalian respiratory sinus arrhythmia, for which functional roles have been sought, are evolutionary relics that had their physiological role defined in ancient representatives of the vertebrates with undivided circulatory systems.

Cardiorespiratory interactions previously identified as mammalian are present in the primitive lungfish

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Monteiro, Diana A.; Taylor, Edwin W.; Sartori, Marina R.; Cruz, André L.; Rantin, Francisco T.; Leite, Cleo A. C.

2018-01-01

The present study has revealed that the lungfish has both structural and functional features of its system for physiological control of heart rate, previously considered solely mammalian, that together generate variability (HRV). Ultrastructural and electrophysiological investigation revealed that the nerves connecting the brain to the heart are myelinated, conferring rapid conduction velocities, comparable to mammalian fibers that generate instantaneous changes in heart rate at the onset of each air breath. These respiration-related changes in beat-to-beat cardiac intervals were detected by complex analysis of HRV and shown to maximize oxygen uptake per breath, a causal relationship never conclusively demonstrated in mammals. Cardiac vagal preganglionic neurons, responsible for controlling heart rate via the parasympathetic vagus nerve, were shown to have multiple locations, chiefly within the dorsal vagal motor nucleus that may enable interactive control of the circulatory and respiratory systems, similar to that described for tetrapods. The present illustration of an apparently highly evolved control system for HRV in a fish with a proven ancient lineage, based on paleontological, morphological, and recent genetic evidence, questions much of the anthropocentric thinking implied by some mammalian physiologists and encouraged by many psychobiologists. It is possible that some characteristics of mammalian respiratory sinus arrhythmia, for which functional roles have been sought, are evolutionary relics that had their physiological role defined in ancient representatives of the vertebrates with undivided circulatory systems. PMID:29507882

A Chinese Decoction, Kuan-Sin-Yin, Improves Autonomic Function and Cancer-Related Symptoms of Metastatic Colon Cancer.

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Chien, Tsai-Ju; Liu, Chia-Yu; Ko, Pin-Hao; Hsu, Chung-Hua

2016-03-01

Kuan-Sin-Yin (KSY) is a traditional Chinese medicine (TCM) decoction, which has been shown to have cytostatic effects on cancer cells and involved in the TCM theory of promoting yin-yang balance.Sonce many cancer patients suffer from autonomic dysfunction (AD), which correspond to yin-yang imbalance in TCM. The aim of this study is to evaluate the possible effect of KSY in metastatic colon cancer (mCRC) patients with AD. We conducted a single-group experiment. Total 52 qualified patients were enrolled. Participants took the KSY daily for 2 weeks. The primary outcome was KSY efficacy as reflected in the heart rate variability (HRV) and electrical conductivity (µA) over 12 meridian points. Autonomic function was examined before and after the KSY intervention. The vagal and sympathetic tone were recorded by HRV; 12 meridian energies were measured using a meridian energy analysis device. Secondary outcomes were cancer-related symptoms and patient quality of life (QoL). The results showed that the KSY intervention improved AD via increasing the vagal tone (HF: P = .041), but not the sympathetic tone (LF: P = .154); total autonomic activity was significantly enhanced (HRV activity: P = .013). Intriguingly, energy increased more over the yin meridian (P = .010) than over the yang meridian (P = .015). Cancer-related symptoms and QoL were significantly improved (P yin-yang concept of energy. © The Author(s) 2015.

Validation of PC-based Sound Card with Biopac for Digitalization of ECG Recording in Short-term HRV Analysis.

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Maheshkumar, K; Dilara, K; Maruthy, K N; Sundareswaren, L

2016-07-01

Heart rate variability (HRV) analysis is a simple and noninvasive technique capable of assessing autonomic nervous system modulation on heart rate (HR) in healthy as well as disease conditions. The aim of the present study was to compare (validate) the HRV using a temporal series of electrocardiograms (ECG) obtained by simple analog amplifier with PC-based sound card (audacity) and Biopac MP36 module. Based on the inclusion criteria, 120 healthy participants, including 72 males and 48 females, participated in the present study. Following standard protocol, 5-min ECG was recorded after 10 min of supine rest by Portable simple analog amplifier PC-based sound card as well as by Biopac module with surface electrodes in Leads II position simultaneously. All the ECG data was visually screened and was found to be free of ectopic beats and noise. RR intervals from both ECG recordings were analyzed separately in Kubios software. Short-term HRV indexes in both time and frequency domain were used. The unpaired Student's t-test and Pearson correlation coefficient test were used for the analysis using the R statistical software. No statistically significant differences were observed when comparing the values analyzed by means of the two devices for HRV. Correlation analysis revealed perfect positive correlation (r = 0.99, P < 0.001) between the values in time and frequency domain obtained by the devices. On the basis of the results of the present study, we suggest that the calculation of HRV values in the time and frequency domains by RR series obtained from the PC-based sound card is probably as reliable as those obtained by the gold standard Biopac MP36.

Medical Devices; Neurological Devices; Classification of the External Vagal Nerve Stimulator for Headache. Final order.

Science.gov (United States)

2017-12-27

The Food and Drug Administration (FDA or we) is classifying the external vagal nerve stimulator for headache into class II (special controls). The special controls that apply to the device type are identified in this order and will be part of the codified language for the external vagal nerve stimulator for headache's classification. We are taking this action because we have determined that classifying the device into class II (special controls) will provide a reasonable assurance of safety and effectiveness of the device. We believe this action will also enhance patients' access to beneficial innovative devices, in part by reducing regulatory burdens.

Food-intake dysregulation in type 2 diabetic Goto-Kakizaki rats: hypothesized role of dysfunctional brainstem thyrotropin-releasing hormone and impaired vagal output.

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Zhao, K; Ao, Y; Harper, R M; Go, V L W; Yang, H

2013-09-05

Thyrotropin-releasing hormone (TRH), a neuropeptide contained in neural terminals innervating brainstem vagal motor neurons, enhances vagal outflow to modify multisystemic visceral functions and food intake. Type 2 diabetes (T2D) and obesity are accompanied by impaired vagal functioning. We examined the possibility that impaired brainstem TRH action may contribute to the vagal dysregulation of food intake in Goto-Kakizaki (GK) rats, a T2D model with hyperglycemia and impaired central vagal activation by TRH. Food intake induced by intracisternal injection of TRH analog was reduced significantly by 50% in GK rats, compared to Wistar rats. Similarly, natural food intake in the dark phase or food intake after an overnight fast was reduced by 56-81% in GK rats. Fasting (48h) and refeeding (2h)-associated changes in serum ghrelin, insulin, peptide YY, pancreatic polypeptide and leptin, and the concomitant changes in orexigenic or anorexigenic peptide expression in the brainstem and hypothalamus, all apparent in Wistar rats, were absent or markedly reduced in GK rats, with hormone release stimulated by vagal activation, such as ghrelin and pancreatic polypeptide, decreased substantially. Fasting-induced Fos expression accompanying endogenous brainstem TRH action decreased by 66% and 91%, respectively, in the nucleus tractus solitarius (NTS) and the dorsal motor nucleus of the vagus (DMV) in GK rats, compared to Wistar rats. Refeeding abolished fasting-induced Fos-expression in the NTS, while that in the DMV remained in Wistar but not GK rats. These findings indicate that dysfunctional brainstem TRH-elicited vagal impairment contributes to the disturbed food intake in T2D GK rats, and may provide a pathophysiological mechanism which prevents further weight gain in T2D and obesity. Published by Elsevier Ltd.

Organizational justice is related to heart rate variability in white-collar workers, but not in blue-collar workers-findings from a cross-sectional study.

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Herr, Raphael M; Bosch, Jos A; van Vianen, Annelies E M; Jarczok, Marc N; Thayer, Julian F; Li, Jian; Schmidt, Burkhard; Fischer, Joachim E; Loerbroks, Adrian

2015-06-01

Perceived injustice at work predicts coronary heart disease. Vagal dysregulation represents a potential psychobiological pathway. We examined associations between organizational justice and heart rate variability (HRV) indicators. Grounded in social exchange and psychological contract theory, we tested predictions that these associations are more pronounced among white-collar than among blue-collar workers. Cross-sectional data from 222 blue-collar and 179 white-collar men were used. Interactional and procedural justice were measured by questionnaire. Ambulatory HRV was assessed across 24 h. Standardized regression coefficients (β) were calculated. Among white-collar workers, interactional justice showed positive relationships with 24-h HRV, which were strongest during sleeping time (adjusted βs≥0.26; p values≤0.01). No associations were found for blue-collar workers. A comparable but attenuated pattern was observed for procedural justice. Both dimensions of organizational injustice were associated with lowered HRV among white-collar workers. The impact of justice and possibly its association with health seems to differ by occupational groups.

A comparison of heart rate variability, n-3 PUFA status and lipid mediator profile in age- and BMI-matched middle-aged vegans and omnivores.

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Pinto, Ana M; Sanders, Thomas A B; Kendall, Alexandra C; Nicolaou, Anna; Gray, Robert; Al-Khatib, Haya; Hall, Wendy L

2017-03-01

Low heart rate variability (HRV) predicts sudden cardiac death. Long-chain (LC) n-3 PUFA (C20-C22) status is positively associated with HRV. This cross-sectional study investigated whether vegans aged 40-70 years (n 23), whose diets are naturally free from EPA (20 : 5n-3) and DHA (22 : 6n-3), have lower HRV compared with omnivores (n 24). Proportions of LC n-3 PUFA in erythrocyte membranes, plasma fatty acids and concentrations of plasma LC n-3 PUFA-derived lipid mediators were significantly lower in vegans. Day-time interbeat intervals (IBI), adjusted for physical activity, age, BMI and sex, were significantly shorter in vegans compared with omnivores (mean difference -67 ms; 95 % CI -130, -3·4, P50 % and high-frequency power) were similarly lower in vegans, with no differences during sleep. In conclusion, vegans have higher 24 h SDNN, but lower day-time HRV and shorter day-time IBI relative to comparable omnivores. Vegans may have reduced availability of precursor markers for pro-resolving lipid mediators; it remains to be determined whether there is a direct link with impaired cardiac function in populations with low-n-3 status.

Insulin resistance and carotid intima-media thickness mediate the association between resting-state heart rate variability and executive function: A path modelling study.

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Kemp, Andrew H; López, Santiago Rodríguez; Passos, Valeria M A; Bittencourt, Marcio S; Dantas, Eduardo M; Mill, José G; Ribeiro, Antonio L P; Thayer, Julian F; Bensenor, Isabela M; Lotufo, Paulo A

2016-05-01

Research has linked high-frequency heart rate variability (HF-HRV) to cognitive function. The present study adopts a modern path modelling approach to understand potential causal pathways that may underpin this relationship. Here we examine the association between resting-state HF-HRV and executive function in a large sample of civil servants from Brazil (N=8114) recruited for the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). HF-HRV was calculated from 10-min resting-state electrocardiograms. Executive function was assessed using the trail-making test (version B). Insulin resistance (a marker of type 2 diabetes mellitus) and carotid intima-media thickness (subclinical atherosclerosis) mediated the relationship between HRV and executive function in seriatim. A limitation of the present study is its cross-sectional design; therefore, conclusions must be confirmed in longitudinal study. Nevertheless, findings support that possibility that HRV provides a 'spark' that initiates a cascade of adverse downstream effects that subsequently leads to cognitive impairment. Copyright © 2016 Elsevier B.V. All rights reserved.

Depression, anxiety, and heart rate variability: A case-control study in Taiwan

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Li-Fen Chen

2014-01-01

Full Text Available Objective: Decreased heart rate variability (HRV has been reported in persons with major depressive disorder (MDD, but the results obtained are inconsistent. Little is known about the impact of comorbid anxiety disorders on HRV in MDD patients. Both issues necessitate further investigation. Materials and Methods: Forty-nine unmedicated, physically healthy, MDD patients without comorbidity, 21 MDD patients with comorbid generalized anxiety disorder (GAD, 24 MDD patients with comorbid panic disorder (PD, and 81 matched controls were recruited. The Hamilton Depression Rating Scale and the Hamilton Anxiety Rating Scale are employed to assess the severity of depression and anxiety, respectively. The cardiac autonomic function was evaluated by measuring the HRV parameters. The frequency-domain indices of HRV were obtained. Results: MDD patients without comorbidity had lower high-frequency (HF-HRV (which reflected vagal control of HRV than controls. Any comorbid anxiety disorder (GAD or PD was associated with significantly faster heart rates, relative to the controls, and caused greater reductions in HF-HRV among MDD patients. MDD participants with comorbid GAD displayed the greatest reductions in HF-HRV, relative to controls. Correlation analyses revealed that the severity of both depression and anxiety were significantly associated with the mean R wave to R wave (R-R intervals, variance, low-frequency (LF-HRV, and HF-HRV. Conclusion: The present results show decreased HRV in MDD patients, suggesting that reduction in HRV is a psychophysiological marker of MDD. MDD patients with comorbid GAD had the greatest reductions in HRV. Further investigation of the links between MDD and comorbid GAD, HRV, and cardiovascular disease is warranted.

Abnormal Cardiovascular Sympathetic and Parasympathetic Responses to Physical and Emotional Stimuli in Depersonalization Disorder.

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Andrew Paul Owens

2015-03-01

Full Text Available Depersonalization disorder (DPD is characterized by subjective unreality, disembodiment, emotional numbing and reduced psychogenic sympathoexcitation. 3 related experiments used physical and emotional challenges in 14 DPD participants and 16 controls to elucidate whether the cardiovascular sympathetic (SNS and parasympathetic (PNS nervous systems are implicated in DPD and if blunted DPD sympathoexcitation is peripherally or centrally mediated. Participants completed the Beck Anxiety Inventory (BAI, Dissociative Experience Scale (DES and Cambridge Depersonalization Scale (CDS. Study I recorded heart rate (HR and blood pressure (BP during 5mins supine baseline, 3mins handgrip (HG, 3mins cold pressor (CP and 5mins 60°head-up tilt (HUT. Study II recorded HR, BP and heart rate variability (HRV during 5mins HUT and unpleasant images. Study III examined HR and BP orienting responses (ORs to HUT and unpleasant, neutral and pleasant images. DPD BAI (p=0.0004, DES (p=.0002 and CDS (p=< 0.0001 scores were higher than controls. The DPD group produced diminished diastolic BP (DBP (p=0.045 increases to HG. Other indices were comparable between groups. DPD participants produced diminished systolic BP (SBP (p=0.003 and DBP (p=0.002 increases, but greater (p=0.004 HR increases to CP. In study II, DPD high frequency HRV (HF-HRV – indicating parasympathetic vagal activity - was reduced (p=0.029. In study III, DPD DBP was higher throughout the 5s duration of HUT/pseudorandom unpleasant image presentation (1s [p=0.002], 2s [p=0.033], 3s [p=0.001], 4s [p=0.009], 5s [p=0.029]. Study I’s BP pressor data supports previous findings of suppressed sympathoexcitatioin DPD. The greater HR increases to CP, decreased HF-HRV in study II, and increased DBP during unpleasant ORs in study III implicates the SNS and PNS in DPD pathophysiology. These studies suggest the cardiovascular autonomic dysregulation in DPD is likely to be centrally-mediated

Cardiac vagal regulation in infancy predicts executive function and social competence in preschool: Indirect effects through language.

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Whedon, Margaret; Perry, Nicole B; Calkins, Susan D; Bell, Martha A

2018-05-21

Parasympathetic nervous system functioning in infancy may serve a foundational role in the development of cognitive and socioemotional skills (Calkins, 2007). In this study (N = 297), we investigated the potential indirect effects of cardiac vagal regulation in infancy on children's executive functioning and social competence in preschool via expressive and receptive language in toddlerhood. Vagal regulation was assessed at 10 months during two attention conditions (social, nonsocial) via task-related changes in respiratory sinus arrhythmia (RSA). A path analysis revealed that decreased RSA from baseline in the nonsocial condition and increased RSA in the social condition were related to larger vocabularies in toddlerhood. Additionally, children's vocabulary sizes were positively related to their executive function and social competence in preschool. Indirect effects from vagal regulation in both contexts to both 4-year outcomes were significant, suggesting that early advances in language may represent a mechanism through which biological functioning in infancy impacts social and cognitive functioning in childhood. © 2018 Wiley Periodicals, Inc.

Smart ECG Monitoring Patch with Built-in R-Peak Detection for Long-Term HRV Analysis.

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Lee, W K; Yoon, H; Park, K S

2016-07-01

Since heart rate variability (HRV) analysis is widely used to evaluate the physiological status of the human body, devices specifically designed for such applications are needed. To this end, we developed a smart electrocardiography (ECG) patch. The smart patch measures ECG using three electrodes integrated into the patch, filters the measured signals to minimize noise, performs analog-to-digital conversion, and detects R-peaks. The measured raw ECG data and the interval between the detected R-peaks can be recorded to enable long-term HRV analysis. Experiments were performed to evaluate the performance of the built-in R-wave detection, robustness of the device under motion, and applicability to the evaluation of mental stress. The R-peak detection results obtained with the device exhibited a sensitivity of 99.29%, a positive predictive value of 100.00%, and an error of 0.71%. The device also exhibited less motional noise than conventional ECG recording, being stable up to a walking speed of 5 km/h. When applied to mental stress analysis, the device evaluated the variation in HRV parameters in the same way as a normal ECG, with very little difference. This device can help users better understand their state of health and provide physicians with more reliable data for objective diagnosis.

Trajectories of Terminally Ill Patients' Cardiovascular Response to Receptive Music Therapy in Palliative Care.

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Warth, Marco; Kessler, Jens; Hillecke, Thomas K; Bardenheuer, Hubert J

2016-08-01

Relaxation interventions are frequently used to promote symptom relief in palliative care settings, but little is known about the underlying mechanisms. The present analysis aimed at examining the psychophysiological pathways of terminally ill patients' cardiovascular response to a live music therapy vs. prerecorded mindfulness exercise. Eighty-four patients of a palliative care unit were randomly assigned to either of the two interventions. Multilevel modeling was used to analyze trajectories of physiological change. Vagally mediated heart rate variability (VM-HRV) and blood volume pulse amplitude (BVP-A) served as indices of autonomic nervous system response. Participants' gender, age, baseline scores, self-rated pain, and assignment to treatment were entered to the models as predictors. Both VM-HRV and BVP-A showed significant linear and quadratic trends over time, as well as substantial heterogeneity among individuals' trajectories. Baseline scores, pain, and treatment significantly accounted for random variation in VM-HRV intercepts. BVP-A levels were significantly higher in women than in men. Moreover, assignment to treatment significantly accounted for differences in the linear slopes of peripheral blood flow. Higher levels of VM-HRV in the music therapy group highlight the importance of a therapeutic relationship for the effectiveness of relaxation interventions in end-of-life care settings. Music therapy caused significantly stronger reductions of vascular sympathetic tone and, therefore, may be indicated in the treatment of pain and stress-related symptoms in palliative care. Initial self-ratings of pain moderated patients' physiological response and need to be taken into account in clinical practice and future theory building. Copyright © 2016 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

Combination of Empirical Mode Decomposition Components of HRV Signals for Discriminating Emotional States

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Ateke Goshvarpour

2016-06-01

Full Text Available Introduction Automatic human emotion recognition is one of the most interesting topics in the field of affective computing. However, development of a reliable approach with a reasonable recognition rate is a challenging task. The main objective of the present study was to propose a robust method for discrimination of emotional responses thorough examination of heart rate variability (HRV. In the present study, considering the non-stationary and non-linear characteristics of HRV, empirical mode decomposition technique was utilized as a feature extraction approach. Materials and Methods In order to induce the emotional states, images indicating four emotional states, i.e., happiness, peacefulness, sadness, and fearfulness were presented. Simultaneously, HRV was recorded in 47 college students. The signals were decomposed into some intrinsic mode functions (IMFs. For each IMF and different IMF combinations, 17 standard and non-linear parameters were extracted. Wilcoxon test was conducted to assess the difference between IMF parameters in different emotional states. Afterwards, a probabilistic neural network was used to classify the features into emotional classes. Results Based on the findings, maximum classification rates were achieved when all IMFs were fed into the classifier. Under such circumstances, the proposed algorithm could discriminate the affective states with sensitivity, specificity, and correct classification rate of 99.01%, 100%, and 99.09%, respectively. In contrast, the lowest discrimination rates were attained by IMF1 frequency and its combinations. Conclusion The high performance of the present approach indicated that the proposed method is applicable for automatic emotion recognition.

Effects of aerobic exercise training on heart rate variability during wakefulness and sleep and cardiorespiratory responses of young and middle-aged healthy men

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A.M. Catai

2002-06-01

Full Text Available The purpose of the present study was to evaluate the effects of aerobic physical training (APT on heart rate variability (HRV and cardiorespiratory responses at peak condition and ventilatory anaerobic threshold. Ten young (Y: median = 21 years and seven middle-aged (MA = 53 years healthy sedentary men were studied. Dynamic exercise tests were performed on a cycloergometer using a continuous ramp protocol (12 to 20 W/min until exhaustion. A dynamic 24-h electrocardiogram was analyzed by time (TD (standard deviation of mean R-R intervals and frequency domain (FD methods. The power spectral components were expressed as absolute (a and normalized units (nu at low (LF and high (HF frequencies and as the LF/HF ratio. Control (C condition: HRV in TD (Y: 108, MA: 96 ms; P<0.05 and FD - LFa, HFa - was significantly higher in young (1030; 2589 ms²/Hz than in middle-aged men (357; 342 ms²/Hz only during sleep (P<0.05; post-training effects: resting bradycardia (P<0.05 in the awake condition in both groups; VO2 increased for both groups at anaerobic threshold (P<0.05, and at peak condition only in young men; HRV in TD and FD (a and nu was not significantly changed by training in either groups. The vagal predominance during sleep is reduced with aging. The resting bradycardia induced by short-term APT in both age groups suggests that this adaptation is much more related to intrinsic alterations in sinus node than in efferent vagal-sympathetic modulation. Furthermore, the greater alterations in VO2 than in HRV may be related to short-term APT.

Comparative study of c-Fos expression in rat dorsal vagal complex and nucleus ambiguus induced by different durations of restraint water-immersion stress.

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Zhang, Yu-Yu; Cao, Guo-Hong; Zhu, Wen-Xing; Cui, Xi-Yun; Ai, Hong-Bin

2009-06-30

Restraint water-immersion stress (RWIS) of rats induces vagally-mediated gastric dysfunction. The present work explored the effects of different durations of RWIS on neuronal activities of the dorsal vagal complex (DVC) and the nucleus ambiguous (NA) in rats. Male Wistar rats were exposed to RWIS for 0, 30, 60, 120, or 180 min. Then, a c-Fos immunoperoxidase technique was utilized to assess neuronal activation. Resumptively, c-Fos expression in DVC and NA peaked at 60 min of stress, subsequently decreased gradually with increasing durations of RWIS. Interestingly, the most intense c-Fos expression was observed in the dorsal motor nucleus of the vagus (DMV) during the stress, followed by NA, nucleus of solitary tract (NTS) and area postrema (AP). The peak of c-Fos expression in caudal DMV appeared at 120 min of the stress, slower than that in rostral and intermediate DMV. The c-Fos expression in intermediate and caudal NTS was significantly more intense than that in rostral NTS. These results indicate that the neuronal hyperactivity of DMV, NA, NTS and AP, the primary center that control gastric functions, especially DMV and NA, may play an important role in the disorders of gastric motility and secretion induced by RWIS.

HRV changes before and after radiofrequency ablation in patients with different origin of right ventricular outflow tract ventricular premature contraction

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Yi-Ming Ma

2017-04-01

Full Text Available Objective: To observe the HRV changes before and after the radiofrequency current catheter ablationventricular premature beats originated from different site of right ventricular outflow tract. Methods: A total of 102 patients with frequent RVOT-VPC admitted to our hospital were accepted radiofrequency current catheter ablation (RF. According to the origin of RVOT-VPC, it was divided into 2 groups, one is from ventricular septum, and the other one is from free wall, and in each group, male and female are observed separately. Results: (1 HRV before RF ablation: 1 rMSSD in the female patients with RVOT-VPC from free wall was significantly lower than those from septum; 2 frequency domain index (W, LF were higher than normal range, and in male patients, LF/HF1. (2 HRV after RF ablation: 1 Significant changes were found in female patients with RVOT-VPC from septum, rMSSD, PNN50, HF and LF decreased; 2 In female patients with RVOT-VPC from free wall, rMSSD decreased; 3 In male patients, there were no significant HRV changes found before and after RF ablation. (3 Heart rate changes: 1 In female patients with RVOT-VPC from septum, heart rate decreased significantly [(76.47±9.47 bpm vs (69.29±14.59 bpm]. 2 No significant changes were found in male patients. Conclusion: In patients with RVOT-PVC sympathetic and vagus excitability increased, and after catheter ablation, in female patients with RVOT-PVC originated from septum, the HRV index relating to sympathetic and vagus excitability significantly decreased.

Adrenergic receptors and gastric secretion in dogs. Is a "tonic balance" relationship between vagal and beta 2-adrenergic activity a possibility?

DEFF Research Database (Denmark)

Gottrup, F; Hovendal, C; Bech, K

1984-01-01

The relative influence of adrenergic receptors on gastric acid secretion in the dog stomach with different vagal activity or "tone" is almost unknown. beta-adrenoceptors seem to be most important for the direct effect of adrenergic stimulation on acid secretion. In this study the effects...... acid secretion was not influenced significantly by beta-blockade. Similar dose-response curves were found for non-vagotomized dogs with high beta 2-adrenergic tone and dogs with low vagal tone (vagotomy) after pentagastrin and histamine stimulated acid secretion. This study indicates...... that a counterbalance between beta 2-adrenergic and cholinergic vagal tone exists. A "tonic balance theory" is suggested and is probably involved in the resulting acid secretion after vagotomy....

Social Adversity and Antisocial Behavior: Mediating Effects of Autonomic Nervous System Activity.

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Fagan, Shawn E; Zhang, Wei; Gao, Yu

2017-11-01

The display of antisocial behaviors in children and adolescents has been of interest to criminologists and developmental psychologists for years. Exposure to social adversity is a well-documented predictor of antisocial behavior. Additionally, measures of autonomic nervous system (ANS) activity, including heart rate variability (HRV), pre-ejection period (PEP), and heart rate, have been associated with antisocial behaviors including rule-breaking and aggression. Social neuroscience research has begun to investigate how neurobiological underpinnings affect the relationship between social adversity and antisocial/psychopathic behavior in children and adolescents. This study investigated the potential mediating effects of ANS activity on the relationship between social adversity and antisocial behavior in a group of 7- to 10-year-old children from the community (N = 339; 48.2% male). Moderated multiple mediation analyses revealed that low resting heart rate, but not PEP or HRV, mediated the relationship between social adversity and antisocial behavior in males only. Social adversity but not ANS measures were associated with antisocial behavior in females. Findings have implications for understanding the neural influences that underlie antisocial behavior, illustrate the importance of the social environment regarding the expression of these behaviors, and highlight essential gender differences.

Is Baseline Cardiac Autonomic Modulation Related to Performance and Physiological Responses Following a Supramaximal Judo Test?

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Blasco-Lafarga, Cristina; Martínez-Navarro, Ignacio; Mateo-March, Manuel

2013-01-01

Little research exists concerning Heart Rate (HR) Variability (HRV) following supramaximal efforts focused on upper-body explosive strength-endurance. Since they may be very demanding, it seems of interest to analyse the relationship among performance, lactate and HR dynamics (i.e. HR, HRV and complexity) following them; as well as to know how baseline cardiac autonomic modulation mediates these relationships. The present study aimed to analyse associations between baseline and post-exercise HR dynamics following a supramaximal Judo test, and their relationship with lactate, in a sample of 22 highly-trained male judoists (20.70±4.56 years). A large association between the increase in HR from resting to exercise condition and performance suggests that individuals exerted a greater sympathetic response to achieve a better performance (Rating of Perceived Exertion: 20; post-exercise peak lactate: 11.57±2.24 mmol/L; 95.76±4.13 % of age-predicted HRmax). Athletes with higher vagal modulation and lower sympathetic modulation at rest achieved both a significant larger ∆HR and a faster post-exercise lactate removal. A enhanced resting parasympathetic modulation might be therefore related to a further usage of autonomic resources and a better immediate metabolic recovery during supramaximal exertions. Furthermore, analyses of variance displayed a persistent increase in α1 and a decrease in lnRMSSD along the 15 min of recovery, which are indicative of a diminished vagal modulation together with a sympathovagal balance leaning to sympathetic domination. Eventually, time-domain indices (lnRMSSD) showed no lactate correlations, while nonlinear indices (α1 and lnSaEn) appeared to be moderate to strongly correlated with it, thus pointing to shared mechanisms between neuroautonomic and metabolic regulation. PMID:24205273

Job strain and vagal recovery during sleep in shift working health care professionals.

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Karhula, Kati; Henelius, Andreas; Härmä, Mikko; Sallinen, Mikael; Lindholm, Harri; Kivimäki, Mika; Vahtera, Jussi; Puttonen, Sampsa

2014-12-01

Within sample female nurses/nurse assistants in three shift work, we explored the association of job strain with heart rate variability before and during sleep. The participants (n = 95) were recruited from the Finnish Public Sector Study, from hospital wards that belonged either to the top (high job strain [HJS], n = 42) or bottom quartiles on job strain (low job strain [LJS], n = 53) as rated by Job Content Questionnaire responses. A further inclusion criterion was that participants' own job strain was at least as high (HJS group) or low (LJS group) as their ward's average estimation. Three-week field measurements included sleep diary and actigraphy to study the participants' sleep patterns and sleep-wake rhythm. A subset of three pre-selected, circadian rhythm and recovery controlled measurement days, one morning shift, one night shift and a day off, included 24-h heart rate variability (HRV) measurements. The bootstrapped HRV parameters (HR, HF, LF, LF-to-HF-ratio and RMSSD) 30 min before and during 30 min of sleep with lowest average heart rate showed no statistically significant job strain group differences. No association of exposure to stressful work environment and HRV before and during sleep was found.

Diminution of Heart Rate Variability in Bipolar Depression

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Brandon Hage

2017-12-01

Full Text Available Autonomic nervous system (ANS dysregulation in depression is associated with symptoms associated with the ANS. The beat-to-beat pattern of heart rate defined as heart rate variability (HRV provides a noninvasive portal to ANS function and has been proposed to represent a means of quantifying resting vagal tone. We quantified HRV in bipolar depressed (BDD patients as a measure of ANS dysregulation seeking to establish HRV as a potential diagnostic and prognostic biomarker for treatment outcome. Forty-seven BDD patients were enrolled. They were randomized to receive either escitalopram–celecoxib or escitalopram-placebo over 8 weeks in a double-blind study design. Thirty-five patients completed the HRV studies. Thirty-six healthy subjects served as controls. HRV was assessed at pretreatment and end of study and compared with that of controls. HRV was quantified and corrected for artifacts using an algorithm that incorporates time and frequency domains to address non-stationarity of the beat-to-beat heart rate pattern. Baseline high frequency-HRV (i.e., respiratory sinus arrhythmia was lower in BDD patients than controls, although the difference did not reach significance. Baseline low-frequency HRV was significantly lower in BDD patients (ln4.20 than controls (ln = 5.50 (p < 0.01. Baseline heart period was significantly shorter (i.e., faster heart rate in BDD patients than controls. No significant change in HRV parameters were detected over the course of the study with either treatment. These findings suggest that components of HRV may be diminished in BDD patients.

Research on alteration of neurons in vagal nuclei in medulla oblongata in newborns with respiratory distress.

Science.gov (United States)

Islami, Hilmi; Shabani, Ragip; Shabani, Driton; Dacaj, Ramadan; Manxhuka, Suzana; Azemi, Mehmedali; Krasniqi, Shaip; Kurtishi, Ilir

2011-01-01

Neuronal and axonal degenerative changes in motor vagal neurons (DMNV) and sensory vagal neurons (nTS) in the medulla oblongata in newborns were studied. Material was taken from the autopsies of newborns, live and dead newborns, in different gestational weeks (aborted, immature, premature and mature). 46 cases were studied. Material for research was taken from the medulla oblongata and lung tissue. Serial horizontal incisions were made in the medulla oblongata (± 4 mm), commencing from the obex, where the DMNV and nTS vagal nuclei were explored. Fixed cuttings in buffered formalin (10%) were used for histochemical staining. Serial cuttings were done with a microtome (7 µm). Pulmonary infections, being significant (p medulla oblongata in newborns in different gestational weeks are more emphasized in matures in comparison to aborted and immature (p < 0.05). Depending on the lifetime of dead newborns, neuronal morphological changes in vagus nerve nuclei are significant (p < 0.05). Therefore, it can be concluded that pulmonary infections are often caused due to dramatic respiratory distress in newborns, while hypoxaemic changes in the population of vagus nerve neurons in respiratory distress are more emphasized in matures.

Non-linear Heart Rate Variability as a Discriminator of Internalizing Psychopathology and Negative Affect in Children With Internalizing Problems and Healthy Controls

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Charlotte Fiskum

2018-05-01

Full Text Available Background: Internalizing psychopathology and dysregulated negative affect are characterized by dysregulation in the autonomic nervous system and reduced heart rate variability (HRV due to increases in sympathetic activity alongside reduced vagal tone. The neurovisceral system is however, a complex nonlinear system, and nonlinear indices related to psychopathology are so far less studied in children. Essential nonlinear properties of a system can be found in two main domains: the informational domain and the invariant domain. sample entropy (SampEn is a much-used method from the informational domain, while detrended fluctuation analysis (DFA represents a widely-used method from the invariant domain. To see if nonlinear HRV can provide information beyond linear indices of autonomic activation, this study investigated SampEn and DFA as discriminators of internalizing psychopathology and negative affect alongside measures of vagally-mediated HRV and sympathetic activation.Material and Methods: Thirty-Two children with internalizing difficulties and 25 healthy controls (aged 9–13 were assessed with the Child Behavior Checklist and the Early Adolescent Temperament Questionnaire, Revised, giving an estimate of internalizing psychopathology, negative affect and effortful control, a protective factor against psychopathology. Five minute electrocardiogram and impedance cardiography recordings were collected during a resting baseline, giving estimates of SampEn, DFA short-term scaling exponent α1, root mean square of successive differences (RMSSD, and pre-ejection period (PEP. Between-group differences and correlations were assessed with parametric and non-parametric tests, and the relationships between cardiac variables, psychopathology and negative affect were assessed using generalized linear modeling.Results: SampEn and DFA were not significantly different between the groups. SampEn was weakly negatively related to heart rate (HR in the controls

Effects of slow breathing rate on heart rate variability and arterial baroreflex sensitivity in essential hypertension.

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Li, Changjun; Chang, Qinghua; Zhang, Jia; Chai, Wenshu

2018-05-01

This study is to investigate the effects of slow breathing on heart rate variability (HRV) and arterial baroreflex sensitivity in essential hypertension.We studied 60 patients with essential hypertension and 60 healthy controls. All subjects underwent controlled breathing at 8 and 16 breaths per minute. Electrocardiogram, respiratory, and blood pressure signals were recorded simultaneously. We studied effects of slow breathing on heart rate, blood pressure and respiratory peak, high-frequency (HF) power, low-frequency (LF) power, and LF/HF ratio of HRV with traditional and corrected spectral analysis. Besides, we tested whether slow breathing was capable of modifying baroreflex sensitivity in hypertensive subjects.Slow breathing, compared with 16 breaths per minute, decreased the heart rate and blood pressure (all P hypertensive subjects. Slow breathing increased baroreflex sensitivity in hypertensive subjects (from 59.48 ± 6.39 to 78.93 ± 5.04 ms/mm Hg, P hypertension. Besides, slow breathing increased baroreflex sensitivity in hypertensive subjects. These demonstrate slow breathing is indeed capable of shifting sympatho-vagal balance toward vagal activities and increasing baroreflex sensitivity, suggesting a safe, therapeutic approach for essential hypertension.

Physiological and performance adaptations to an in-season soccer camp in the heat: Associations with heart rate and heart rate variability

DEFF Research Database (Denmark)

Buchheit, M; Voss, S C; Nybo, Lars

2011-01-01

The aim of the present study was to examine the associations between adaptive responses to an in-season soccer training camp in the heat and changes in submaximal exercising heart rate (HRex, 5-min run at 9 ¿km/h), postexercise HR recovery (HRR) and HR variability (HRV). Fifteen well-trained but ......The aim of the present study was to examine the associations between adaptive responses to an in-season soccer training camp in the heat and changes in submaximal exercising heart rate (HRex, 5-min run at 9 ¿km/h), postexercise HR recovery (HRR) and HR variability (HRV). Fifteen well......-trained but non-heat-acclimatized male adult players performed a training week in Qatar (34.6¿±¿1.9°C wet bulb globe temperature). HRex, HRR, HRV (i.e. the standard deviation of instantaneous beat-to-beat R-R interval variability measured from Poincaré plots SD1, a vagal-related index), creatine kinase (CK...... at the beginning and at the end of the training week. Throughout the intervention, HRex and HRV showed decreasing (P¿...

ENVIRONMENTAL CHANGES ANALYSIS IN BUCHAREST CITY USING CORONA, SPOT HRV AND IKONOS IMAGES

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I. Noaje

2012-08-01

Full Text Available Bucharest, capital of Romania, deals with serious difficulties as a result of urban politics: influx of people due to industrialization and development of dormitory areas, lack of a modern infrastructure, absence of coherent and long term urban development politics, continuous depletion of environment. This paper presents a multisensor study relying on multiple data sets, both analogical and digital: satellite images (Corona – 1964 panchromatic, SPOT HRV – 1994 multispctral and panchromatic, IKONOS – 2007 multispectral, aerial photographs – 1994, complementary products (topographic and thematic maps. Georeferenced basis needs to be generated to highlight changes detection. The digital elevation model is generated from aerial photography 1:5,000 scaled, acquired in 1994. First a height correction is required followed by an affine transformation to the ground control points identified both in aerial photographs and IKONOS image. SPOT-HRV pansharpened satellite image has been rectified on georeferenced IKONOS image, by an affine transformation method. The Corona panoramic negative film was scanned and rubber sheeting method is used for rectification. The first 25 years of the study period (1964–1989 are characterized by growth of industrial areas, high density apartment buildings residential areas and leisure green areas by demolition of cultural heritage areas (hundred years old churches and architectural monuments. Changes between the imagery were determined partially through visual interpretation, using elements such as location, size, shape, shadow, tone, texture, and pattern (Corona image, partially using unsupervised classification (SPOT HRV and IKONOS. The second period of 18 years (1989–2007 highlighted considerable growth of residential areas in the city neighborhood, simultaneously with the diminish of green areas and massive deforestation in confiscated areas before and returned to the original owners.

Impact of gonadectomy on sympatho-vagal balance in male and female normotensive rat

NARCIS (Netherlands)

Pijacka, Wioletta; Clifford, Bethan; Walas, Dawid; Tilburgs, Chantal; Joles, Jaap A; McMullen, Sarah; Langley-Evans, Simon C

OBJECTIVE: It is well established that autonomic nervous system and sympatho-vagal balance plays an important role in maintaining arterial blood pressure (ABP) (Salman IM., 2016) and that autonomic regulation of ABP differs between males and females (Hart EC et al., 2014). We hypothesised that sex

Comparison of Physical Therapy with Energy Healing for Improving Range of Motion in Subjects with Restricted Shoulder Mobility

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Ann Linda Baldwin

2013-01-01

Full Text Available Two forms of energy healing, Reconnective Healing (RH and Reiki, which involve light or no touch, were tested for efficacy against physical therapy (PT for increasing limited range of motion (ROM of arm elevation in the scapular plane. Participants were assigned to one of 5 groups: PT, Reiki, RH, Sham Healing, or no treatment. Except for no treatment, participants were blinded as to grouping. Range of Motion, self-reported pain, and heart rate variability (HRV were assessed before and after a 10-minute session. On average, for PT, Reiki, RH, Sham Healing, and no treatment, respectively, ROM increased by 12°, 20°, 26°, 0.6°, and 3° and pain score decreased by 11.5%, 10.1%, 23.9%, 15.4%, and 0%. Physical therapy, Reiki, and RH were more effective than Sham Healing for increasing ROM (PT: , ; Reiki: , ; RH: , . It is possible that this improvement was not mediated by myofascial release because the subjects’ HRV did not change, suggesting no significant increase in vagal activity. Sham treatment significantly reduced pain compared to no treatment (, and was just as effective as PT, Reiki, and RH. It is the authors’ opinion that the accompanying pain relief is a placebo effect.

Roux-en-Y gastric bypass reverses the effects of diet-induced obesity to inhibit the responsiveness of central vagal motoneurones.

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Browning, Kirsteen N; Fortna, Samuel R; Hajnal, Andras

2013-05-01

Diet-induced obesity (DIO) has been shown to alter the biophysical properties and pharmacological responsiveness of vagal afferent neurones and fibres, although the effects of DIO on central vagal neurones or vagal efferent functions have never been investigated. The aims of this study were to investigate whether high-fat diet-induced DIO also affects the properties of vagal efferent motoneurones, and to investigate whether these effects were reversed following weight loss induced by Roux-en-Y gastric bypass (RYGB) surgery. Whole-cell patch-clamp recordings were made from rat dorsal motor nucleus of the vagus (DMV) neurones in thin brainstem slices. The DMV neurones from rats exposed to high-fat diet for 12-14 weeks were less excitable, with a decreased membrane input resistance and decreased ability to fire action potentials in response to direct current pulse injection. The DMV neurones were also less responsive to superfusion with the satiety neuropeptides cholecystokinin and glucagon-like peptide 1. Roux-en-Y gastric bypass reversed all of these DIO-induced effects. Diet-induced obesity also affected the morphological properties of DMV neurones, increasing their size and dendritic arborization; RYGB did not reverse these morphological alterations. Remarkably, independent of diet, RYGB also reversed age-related changes of membrane properties and occurrence of charybdotoxin-sensitive (BK) calcium-dependent potassium current. These results demonstrate that DIO also affects the properties of central autonomic neurones by decreasing the membrane excitability and pharmacological responsiveness of central vagal motoneurones and that these changes were reversed following RYGB. In contrast, DIO-induced changes in morphological properties of DMV neurones were not reversed following gastric bypass surgery, suggesting that they may be due to diet, rather than obesity. These findings represent the first direct evidence for the plausible effect of RYGB to improve vagal

The relationship between emotion regulation capacity, heart rate variability, and quality of life in individuals with alcohol-related brain damage

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Steinmetz JP

2016-08-01

Full Text Available Jean-Paul Steinmetz,1,2 Claus Vögele,3,4 Christiane Theisen-Flies,5 Carine Federspiel,1,2 Stefan Sütterlin6,7 1Department of Research and Development, ZithaSenior, 2Centre for Memory and Mobility, ZithaSenior, 3Institute for Health and Behaviour, Integrative Research Unit on Social and Individual Development (INSIDE, University of Luxembourg, Luxembourg; 4Research Group Health Psychology, University of Leuven, Leuven, Belgium; 5Home St Joseph, ZithaSenior, Luxembourg; 6Department of Psychology, Lillehammer University College, Lillehammer, 7Division of Surgery and Clinical Neuroscience, Department of Psychosomatic Medicine, Oslo University Hospital – Rikshospitalet, Oslo, Norway Abstract: The reliable measurement of quality of life (QoL presents a challenge in individuals with alcohol-related brain damage. This study investigated vagally mediated heart rate variability (vmHRV as a physiological predictor of QoL. Self- and proxy ratings of QoL and dysexecutive symptoms were collected once, while vmHRV was repeatedly assessed over a 3-week period at weekly intervals in a sample of nine alcohol-related brain damaged patients. We provide robustness checks, bootstrapped correlations with confidence intervals, and standard errors for mean scores. We observed low to very low heart rate variability scores in our patients in comparison to norm values found in healthy populations. Proxy ratings of the QoL scale “subjective physical and mental performance” and everyday executive dysfunctions were strongly related to vmHRV. Better proxy-rated QoL and fewer dysexecutive symptoms were observed in those patients with higher vmHRV. Overall, patients showed low parasympathetic activation favoring the occurrence of dysfunctional emotion regulation strategies. Keywords: heart rate variability, emotion regulation, alcohol-related brain damage, quality of life

Dietary sodium influences the effect of mental stress on heart rate variability: a randomized trial in healthy adults.

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Allen, Alexander R; Gullixson, Leah R; Wolhart, Sarah C; Kost, Susan L; Schroeder, Darrell R; Eisenach, John H

2014-02-01

Dietary sodium influences intermediate physiological traits in healthy adults independent of changes in blood pressure. The purpose of this study was to test the hypothesis that dietary sodium affects cardiac autonomic modulation during mental stress. In a prospective, randomized cross-over design separated by 1 month between diets, 70 normotensive healthy young adults (F/M: 44/26, aged 18-38 years) consumed a 5-day low (10 mmol/day), normal (150 mmol), and high (400 mmol) sodium diet followed by heart rate variability (HRV) recordings at rest and during 5-min computerized mental arithmetic. Women were studied in the low hormone phase of the menstrual cycle following each diet. Diet did not affect resting blood pressure, but heart rate (HR) (mean ± SE) was 66 ± 1, 64 ± 1, and 63 ± 1 bpm in low, normal, and high sodium conditions, respectively (analysis of variance P = 0.02). For HRV, there was a main effect of sodium on resting SD of normalized RR intervals (SDNN), square root of the mean squared difference of successive normalized RR intervals (RMSSD), high frequency, low-frequency normalized units (LFnu), and high-frequency normalized units (HFnu) (P sodium was most marked and consistent with sympathetic activation and reduced vagal activity, with increased LFnu and decreased SDNN, RMSSD, and HFnu compared to both normal and high sodium conditions (P ≤0.05 for all). Dietary sodium-by-mental stress interactions were significant for mean NN, RMSSD, high-frequency power, LFnu, and low frequency/high frequency ratio (P sodium restriction evoked an increase in resting sympathetic activity and reduced vagal activity to the extent that mental stress caused modest additional disruptions in autonomic balance. Conversely, normal and high sodium evoked a reduction in resting sympathetic activity and incremental increase in resting vagal activity, which were disrupted to a greater extent during mental stress compared to low sodium. We conclude that autonomic control of

Critical Airway Compromise due to a Massive Vagal Schwannoma

LENUS (Irish Health Repository)

McDermott, AM

2016-05-01

We describe the case of a 37-year-old man with a slowly enlarging neck lump and compressive symptoms. He presented to a separate institution 10 years prior where an observational approach was advocated. Following preoperative investigations and embolization, an 11cm vagal schwannoma was excised and vagus nerve was sacrificed. Although conservative management is appropriate for a select patient population, surgical excision is treatment of choice for cervical neurogenic tumours and paraganglionomas and must be considered in young patients or rapidly expanding tumours to avoid compressive symptoms, as in this case.

Avaliando a atividade vagal cardíaca na eletrocardiografia convencional Evaluating cardiac vagal activity on a conventional electrocardiogram

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Flávia P. Teixeira

2007-04-01

Full Text Available OBJETIVO: Determinar a viabilidade da utilização de traçado convencional de eletrocardiografia (ECG para avaliação da atividade vagal cardíaca (AVC. MÉTODOS: Foram analisados, retrospectivamente, 1.395 indivíduos (995 homens, na faixa de idade de 46 + 17,2 anos (média ± desvio padrão, com traçados de ECG convencional para medida do Delta RR, que representa a diferença, em ms, entre o maior e o menor intervalo RR, e com resultados da avaliação autonômica parassimpática, o teste de exercício de quatro segundos (T4s, que quantifica a AVC por meio do índice vagal cardíaco (IVC. Foram obtidas curvas ROC para determinar os valores de Delta RR com melhor relação entre sensibilidade e especificidade para os pontos de corte de baixa e alta AVC, respectivamente, de 1,20 e 1,95. RESULTADOS: Os valores de delta RR correlacionaram-se significativamente com os de IVC (r = 0,40; p 120 ms como os melhores pontos de corte para baixa e alta AVC, com sensibilidade de 75% e 57%, especificidade de 62% e 79% e áreas das curvas ROC de 0,76 e 0,74, respectivamente. CONCLUSÃO: A medida visual do delta RR em um traçado de ECG parece ser válida para a avaliação clínica preliminar e rápida da AVC, podendo ser útil em consultórios, emergências ou situações nas quais o uso de métodos mais sofisticados de avaliação autonômica não seja viável, oportuno ou conveniente.OBJECTIVE: To determine the viability of using a conventional electrocardiogram (ECG tracing for assessment of CVA. METHODS: We retrospectively analyzed 1395 individuals (995 males, aged 46 ± 17.2 years (mean ± standard deviation with conventional ECG tracings to measure the delta RR (which represents the difference in milliseconds (ms between the greatest and smallest RR interval and results of a second autonomic parasympathetic evaluation, the 4-second exercise test (T4s, that quantifies CVA by the cardiac vagal index (CVI. ROC curves were obtained to determine the

Therapeutic effects of selective atrioventricular node vagal stimulation in atrial fibrillation and heart failure.

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Zhang, Youhua; Popović, Zoran B; Kusunose, Kenya; Mazgalev, Todor N

2013-01-01

Atrial fibrillation (AF) and heart failure (HF) frequently coexist. We have previously demonstrated that selective atrioventricular node (AVN) vagal stimulation (AVN-VS) can be used to control ventricular rate during AF. Due to withdrawal of vagal activity in HF, the therapeutic effects of AVN-VS may be compromised in the combined condition of AF and HF. Accordingly, this study was designed to evaluate the therapeutic effects of AVN-VS to control ventricular rate in AF and HF. A combined model of AF and HF was created by implanting a dual chamber pacemaker in 24 dogs. A newly designed bipolar electrode was inserted into the ganglionic AVN fat pad and connected to a nerve stimulator for delivering AVN-VS. In all dogs, HF was induced by high rate ventricular pacing at 220 bpm for 4 weeks. AF was then induced and maintained by rapid atrial pacing at 600 bpm after discontinuation of ventricular pacing. These HF + AF dogs were randomized into control (n = 9) and AVN-VS (n = 15) groups. In the latter group, vagal stimulation (310 μs, 20 Hz, 3-7 mA) was delivered continuously for 6 months. Compared with the control, AVN-VS had a consistent effect on ventricular rate slowing (by >50 bpm, all P AVN-VS was well tolerated by the treated animals. AVN-VS achieved consistent rate slowing, which was associated with improved ventricular function in a canine AF and HF model. Thus, AVN-VS may be a novel, effective therapeutic option in the combined condition of AF and HF. © 2012 Wiley Periodicals, Inc.

Nesfatin-1 activates cardiac vagal neurons of nucleus ambiguus and elicits bradycardia in conscious rats.

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Brailoiu, G Cristina; Deliu, Elena; Tica, Andrei A; Rabinowitz, Joseph E; Tilley, Douglas G; Benamar, Khalid; Koch, Walter J; Brailoiu, Eugen

2013-09-01

Nesfatin-1, a peptide whose receptor is yet to be identified, has been involved in the modulation of feeding, stress, and metabolic responses. More recently, increasing evidence supports a modulatory role for nesfatin-1 in autonomic and cardiovascular activity. This study was undertaken to test if the expression of nesfatin-1 in the nucleus ambiguus, a key site for parasympathetic cardiac control, may be correlated with a functional role. As we have previously demonstrated that nesfatin-1 elicits Ca²⁺ signaling in hypothalamic neurons, we first assessed the effect of this peptide on cytosolic Ca²⁺ in cardiac pre-ganglionic neurons of nucleus ambiguus. We provide evidence that nesfatin-1 increases cytosolic Ca²⁺ concentration via a Gi/o-coupled mechanism. The nesfatin-1-induced Ca²⁺ rise is critically dependent on Ca²⁺ influx via P/Q-type voltage-activated Ca²⁺ channels. Repeated administration of nesfatin-1 leads to tachyphylaxis. Furthermore, nesfatin-1 produces a dose-dependent depolarization of cardiac vagal neurons via a Gi/o-coupled mechanism. In vivo studies, using telemetric and tail-cuff monitoring of heart rate and blood pressure, indicate that microinjection of nesfatin-1 into the nucleus ambiguus produces bradycardia not accompanied by a change in blood pressure in conscious rats. Taken together, our results identify for the first time that nesfatin-1 decreases heart rate by activating cardiac vagal neurons of nucleus ambiguus. Our results indicate that nesfatin-1, one of the most potent feeding peptides, increases cytosolic Ca²⁺ by promoting Ca²⁺ influx via P/Q channels and depolarizes nucleus ambiguus neurons; both effects are Gi/o-mediated. In vivo studies indicate that microinjection of nesfatin-1 into nucleus ambiguus produces bradycardia in conscious rats. This is the first report that nesfatin-1 increases the parasympathetic cardiac tone. © 2013 International Society for Neurochemistry.

Minimal Window Duration for Accurate HRV Recording in Athletes

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Bourdillon, Nicolas; Schmitt, Laurent; Yazdani, Sasan; Vesin, Jean-Marc; Millet, Grégoire P.

2017-01-01

Heart rate variability (HRV) is non-invasive and commonly used for monitoring responses to training loads, fitness, or overreaching in athletes. Yet, the recording duration for a series of RR-intervals varies from 1 to 15 min in the literature. The aim of the present work was to assess the minimum record duration to obtain reliable HRV results. RR-intervals from 159 orthostatic tests (7 min supine, SU, followed by 6 min standing, ST) were analyzed. Reference windows were 4 min in SU (min 3–7) and 4 min in ST (min 9–13). Those windows were subsequently divided and the analyses were repeated on eight different fractioned windows: the first min (0–1), the second min (1–2), the third min (2–3), the fourth min (3–4), the first 2 min (0–2), the last 2 min (2–4), the first 3 min (0–3), and the last 3 min (1–4). Correlation and Bland & Altman statistical analyses were systematically performed. The analysis window could be shortened to 0–2 instead of 0–4 for RMSSD only, whereas the 4-min window was necessary for LF and total power. Since there is a need for 1 min of baseline to obtain a steady signal prior the analysis window, we conclude that studies relying on RMSSD may shorten the windows to 3 min (= 1+2) in SU or seated position only and to 6 min (= 1+2 min SU plus 1+2 min ST) if there is an orthostatic test. Studies relying on time- and frequency-domain parameters need a minimum of 5 min (= 1+4) min SU or seated position only but require 10 min (= 1+4 min SU plus 1+4 min ST) for the orthostatic test. PMID:28848382

Minimal Window Duration for Accurate HRV Recording in Athletes

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Nicolas Bourdillon

2017-08-01

Full Text Available Heart rate variability (HRV is non-invasive and commonly used for monitoring responses to training loads, fitness, or overreaching in athletes. Yet, the recording duration for a series of RR-intervals varies from 1 to 15 min in the literature. The aim of the present work was to assess the minimum record duration to obtain reliable HRV results. RR-intervals from 159 orthostatic tests (7 min supine, SU, followed by 6 min standing, ST were analyzed. Reference windows were 4 min in SU (min 3–7 and 4 min in ST (min 9–13. Those windows were subsequently divided and the analyses were repeated on eight different fractioned windows: the first min (0–1, the second min (1–2, the third min (2–3, the fourth min (3–4, the first 2 min (0–2, the last 2 min (2–4, the first 3 min (0–3, and the last 3 min (1–4. Correlation and Bland & Altman statistical analyses were systematically performed. The analysis window could be shortened to 0–2 instead of 0–4 for RMSSD only, whereas the 4-min window was necessary for LF and total power. Since there is a need for 1 min of baseline to obtain a steady signal prior the analysis window, we conclude that studies relying on RMSSD may shorten the windows to 3 min (= 1+2 in SU or seated position only and to 6 min (= 1+2 min SU plus 1+2 min ST if there is an orthostatic test. Studies relying on time- and frequency-domain parameters need a minimum of 5 min (= 1+4 min SU or seated position only but require 10 min (= 1+4 min SU plus 1+4 min ST for the orthostatic test.

Exercise training improves heart rate variability after methamphetamine dependency.

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Dolezal, Brett Andrew; Chudzynski, Joy; Dickerson, Daniel; Mooney, Larissa; Rawson, Richard A; Garfinkel, Alan; Cooper, Christopher B

2014-06-01

Heart rate variability (HRV) reflects a healthy autonomic nervous system and is increased with physical training. Methamphetamine dependence (MD) causes autonomic dysfunction and diminished HRV. We compared recently abstinent methamphetamine-dependent participants with age-matched, drug-free controls (DF) and also investigated whether HRV can be improved with exercise training in the methamphetamine-dependent participants. In 50 participants (MD = 28; DF = 22), resting heart rate (HR; R-R intervals) was recorded over 5 min while seated using a monitor affixed to a chest strap. Previously reported time domain (SDNN, RMSSD, pNN50) and frequency domain (LFnu, HFnu, LF/HF) parameters of HRV were calculated with customized software. MD were randomized to thrice-weekly exercise training (ME = 14) or equal attention without training (MC = 14) over 8 wk. Groups were compared using paired and unpaired t-tests. Statistical significance was set at P ≤ 0.05. Participant characteristics were matched between groups (mean ± SD): age = 33 ± 6 yr; body mass = 82.7 ± 12 kg, body mass index = 26.8 ± 4.1 kg·min. Compared with DF, the MD group had significantly higher resting HR (P HRV indices were similar between ME and MC groups. However, after training, the ME group significantly (all P HRV, based on several conventional indices, was diminished in recently abstinent, methamphetamine-dependent individuals. Moreover, physical training yielded a marked increase in HRV, representing increased vagal modulation or improved autonomic balance.

Consecutive days of cold water immersion: effects on cycling performance and heart rate variability.

Science.gov (United States)

Stanley, Jamie; Peake, Jonathan M; Buchheit, Martin

2013-02-01

We investigated performance and heart rate (HR) variability (HRV) over consecutive days of cycling with post-exercise cold water immersion (CWI) or passive recovery (PAS). In a crossover design, 11 cyclists completed two separate 3-day training blocks (120 min cycling per day, 66 maximal sprints, 9 min time trialling [TT]), followed by 2 days of recovery-based training. The cyclists recovered from each training session by standing in cold water (10 °C) or at room temperature (27 °C) for 5 min. Mean power for sprints, total TT work and HR were assessed during each session. Resting vagal-HRV (natural logarithm of square-root of mean squared differences of successive R-R intervals; ln rMSSD) was assessed after exercise, after the recovery intervention, during sleep and upon waking. CWI allowed better maintenance of mean sprint power (between-trial difference [90 % confidence limits] +12.4 % [5.9; 18.9]), cadence (+2.0 % [0.6; 3.5]), and mean HR during exercise (+1.6 % [0.0; 3.2]) compared with PAS. ln rMSSD immediately following CWI was higher (+144 % [92; 211]) compared with PAS. There was no difference between the trials in TT performance (-0.2 % [-3.5; 3.0]) or waking ln rMSSD (-1.2 % [-5.9; 3.4]). CWI helps to maintain sprint performance during consecutive days of training, whereas its effects on vagal-HRV vary over time and depend on prior exercise intensity.

Muscular Contraction Mode Differently Affects Autonomic Control During Heart Rate Matched Exercise

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Matthias eWeippert

2015-05-01

Full Text Available The precise contributions of afferent feedback to cardiovascular and respiratory responses to exercise are still unclear. Aim of this crossover study was to assess whether and how autonomic cardiovascular and respiratory control differed in response to dynamic (DYN and isometric contractions (ISO at a similar, low heart rate (HR level. Therefore, 22 healthy males (26.7 ± 3.6 yrs performed two kinds of voluntary exercises at similar HR: ISO and DYN of the right quadriceps femoris muscle. Although HR was eqivalent (82 ± 8 bpm for DYN and ISO, respectively, rating of exertion, blood pressures, and rate pressure product were higher, whereas breathing frequency, minute ventilation, oxygen uptake and carbon dioxide output were significantly lower during ISO. Tidal volume, end-tidal partial pressures of O2 and CO2, respiratory exchange ratio and capillary blood lactate concentration were comparable between both contraction modes. Heart rate variability (HRV indicators, SDNN, HF-Power and LF-Power, representing both vagal and sympathetic influences, were significantly higher during ISO. Sample entropy, a nonlinear measure of HRV was also significantly affected by contraction mode. It can be concluded that, despite the same net effect on HR, the quality of cardiovascular control during low intensity exercise is significantly different between DYN and ISO. HRV analysis indicated a sympatho-vagal coactivation during ISO. Whether mechanoreceptor feedback alone, a change in central command, or the interaction of both mechanisms is the main contributor of the distinct autonomic responses to the different exercise modes remains to be elucidated.

Sympathovagal response to orthostatism in overt and in subclinical hyperthyroidism.

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Goichot, B; Brandenberger, G; Vinzio, S; Perrin, A E; Geny, B; Schlienger, J L; Simon, C

2004-04-01

Heart rate variability (HRV) is a measure of the physiological variation of R-R intervals, reflecting the sympathovagal balance. In both overt and subclinical hyperthyroidism, a relative increase in sympathetic activity has been demonstrated, mainly due to a decrease in vagal activity. The modifications of HRV during orthostatism in normal subjects resemble those seen in hyperthyroidism. We have studied the response of 19 patients with overt hyperthyroidism and 12 with subclinical hyperthyroidism during orthostatism using HRV and compared the results to those of 32 healthy controls. In the three groups, the R-R intervals decreased in the same proportion after orthostatism. The low frequency power (LF)/[LF + high frequency power (HF)] ratio, which reflects the sympathetic tone, also increased in the same proportion in the three groups. However, the mechanisms of the modulation of the sympathovagal balance during orthostatism were different among the three groups. In controls, the relative increase of sympathetic tone after orthostatism was due principally to a decrease in vagal tone (reflected by decreased power in the HF band), while in overt hyperthyroidism, where the power in the HF band was already minimal in the lying position, there was a clear increase in the LF band power during orthostatism. The results were intermediate in the subclinical hyperthyroidism group, reflecting a continuum of effects of the thyroid hormone excess on the autonomic nervous system. Our study shows that despite an apparent normal cardiovascular adaptation to orthostatism in hyperthyroidism, the modulation of the autonomic nervous system is profoundly modified.

Changes of Heart Rate Variability during Methylphenidate Treatment in Attention-Deficit Hyperactivity Disorder Children: A 12-Week Prospective Study.

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Kim, Hayeon Jennifer; Yang, Jaewon; Lee, Moon Soo

2015-09-01

The aim of this study was to clarify the relationship between the autonomic nervous system and attention deficit hyperactivity disorder (ADHD) rating scales and to evaluate the usefulness of heart rate variability (HRV) as a psychophysiological biomarker for ADHD. Subjects were recruited from outpatients in the Department of Child and Adolescent Psychiatry at the Korea University Medical Center from August 2007 to December 2010. Subjects received methylphenidate. Time- and frequency-domain analyses of HRV, the Korean ADHD rating scale (K-ARS), and computerized ADHD diagnostic system were evaluated before treatment. After a 12-week period of medication administration, we repeated the HRV measurements and K-ARS rating. Eighty-six subjects were initially enrolled and 37 participants completed the 12-week treatment and HRV measurements subsequent to the treatment. Significant correlations were found between the K-ARS inattention score and some HRV parameters. All of the HRV parameters, except the standard deviations of the normal-to-normal interval, very low frequency, and low frequency to high frequency, showed a significant positive correlation between baseline and endpoint measures in completers. High frequency (HF) and the square root of the mean squared differences of successive normal-to-normal intervals (RMSSD), which are related to parasympathetic vagal tone, showed significant decreases from baseline to endpoint. The HRV test was shown to be reproducible. The decrease in HF and RMSSD suggests that parasympathetic dominance in ADHD can be altered by methylphenidate treatment. It also shows the possibility that HRV parameters can be used as psychophysiological markers in the treatment of ADHD.

Estimating rice grain protein contents with SPOT/HRV data acquired at maturing stage

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Asaka, D.; Shiga, H.

2003-01-01

Rice grain protein contents that play an important role in the eating quality of rice can be estimated from leaf color in maturing stage. In order to investigate the distribution of paddy rice grain protein of a wide area, we employed SPOT/HRV data from August to September for successive 4 years, selecting the Naganuma town, Hokkaido as the study area. The relationship between each spectral bands and ground survey data were examined. The result showed that the grain protein contents could be estimated using the normalized difference vegetation index (NDVI) with the absolute root mean square error less than 0.4% under the condition that the time lag between the satellite observation date and the maturing stage was within 20 days. In this period, we would have enough chance to get clear observation data every year under the weather conditions in the study area using the SPOT/HRV sensors that has pointing ability. For major rice varieties cultivated in Hokkaido, the same relationship between NDVI and protein contents was observed. Thus, we conclude that the method proposed in this study is operational in rice production

EEG, HRV and Psychological Correlates while Playing Bejeweled II: A Randomized Controlled Study.

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Russoniello, Carmen V; O'Brien, Kevin; Parks, Jennifer M

2009-01-01

Stress related medical disorders such as cardiovascular disease, diabetes, depression, and anxiety are serious medical issues that can cause disability and death. Interventions to prevent their development and exacerbation are needed. Casual video games (CVGs) are fun, easy to play, spontaneous and tremendously popular. People report that they play these games because they decrease their stress and improve their mood. This study tested this theory by comparing people playing Bejeweled II a popular CVG with control subjects measured under similar conditions. Electroencephalographic (EEG) changes after playing Bejeweled II were consistent with increased mood and corroborated with similar findings on psychological reports. Moreover, heart rate variability (HRV) changes consistent with autonomic nervous system relaxation or decreased physical stress were also recorded. It is concluded, therefore, that playing a CVG like Bejeweled II can increase mood and decrease stress. These finding have broad implications and include the potential development of prescriptive interventions using Bejeweled II to prevent and treat stress related medical disorders. Finally, these findings demonstrate a method using EEG, HRV and psychological correlates to understand the psychophysiological or cybernetic interconnection between participant and video game.

Training adaptation and heart rate variability in elite endurance athletes: opening the door to effective monitoring.

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Plews, Daniel J; Laursen, Paul B; Stanley, Jamie; Kilding, Andrew E; Buchheit, Martin

2013-09-01

The measurement of heart rate variability (HRV) is often considered a convenient non-invasive assessment tool for monitoring individual adaptation to training. Decreases and increases in vagal-derived indices of HRV have been suggested to indicate negative and positive adaptations, respectively, to endurance training regimens. However, much of the research in this area has involved recreational and well-trained athletes, with the small number of studies conducted in elite athletes revealing equivocal outcomes. For example, in elite athletes, studies have revealed both increases and decreases in HRV to be associated with negative adaptation. Additionally, signs of positive adaptation, such as increases in cardiorespiratory fitness, have been observed with atypical concomitant decreases in HRV. As such, practical ways by which HRV can be used to monitor training status in elites are yet to be established. This article addresses the current literature that has assessed changes in HRV in response to training loads and the likely positive and negative adaptations shown. We reveal limitations with respect to how the measurement of HRV has been interpreted to assess positive and negative adaptation to endurance training regimens and subsequent physical performance. We offer solutions to some of the methodological issues associated with using HRV as a day-to-day monitoring tool. These include the use of appropriate averaging techniques, and the use of specific HRV indices to overcome the issue of HRV saturation in elite athletes (i.e., reductions in HRV despite decreases in resting heart rate). Finally, we provide examples in Olympic and World Champion athletes showing how these indices can be practically applied to assess training status and readiness to perform in the period leading up to a pinnacle event. The paper reveals how longitudinal HRV monitoring in elites is required to understand their unique individual HRV fingerprint. For the first time, we demonstrate how

Distinct projection targets define subpopulations of mouse brainstem vagal neurons that express the autism-associated MET receptor tyrosine kinase.

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Kamitakahara, Anna; Wu, Hsiao-Huei; Levitt, Pat

2017-12-15

Detailed anatomical tracing and mapping of the viscerotopic organization of the vagal motor nuclei has provided insight into autonomic function in health and disease. To further define specific cellular identities, we paired information based on visceral connectivity with a cell-type specific marker of a subpopulation of neurons in the dorsal motor nucleus of the vagus (DMV) and nucleus ambiguus (nAmb) that express the autism-associated MET receptor tyrosine kinase. As gastrointestinal disturbances are common in children with autism spectrum disorder (ASD), we sought to define the relationship between MET-expressing (MET+) neurons in the DMV and nAmb, and the gastrointestinal tract. Using wholemount tissue staining and clearing, or retrograde tracing in a MET EGFP transgenic mouse, we identify three novel subpopulations of EGFP+ vagal brainstem neurons: (a) EGFP+ neurons in the nAmb projecting to the esophagus or laryngeal muscles, (b) EGFP+ neurons in the medial DMV projecting to the stomach, and (b) EGFP+ neurons in the lateral DMV projecting to the cecum and/or proximal colon. Expression of the MET ligand, hepatocyte growth factor (HGF), by tissues innervated by vagal motor neurons during fetal development reveal potential sites of HGF-MET interaction. Furthermore, similar cellular expression patterns of MET in the brainstem of both the mouse and nonhuman primate suggests that MET expression at these sites is evolutionarily conserved. Together, the data suggest that MET+ neurons in the brainstem vagal motor nuclei are anatomically positioned to regulate distinct portions of the gastrointestinal tract, with implications for the pathophysiology of gastrointestinal comorbidities of ASD. © 2017 Wiley Periodicals, Inc.

Endurance performance and nocturnal HRV indices.

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Nummela, A; Hynynen, E; Kaikkonen, P; Rusko, H

2010-03-01

The effects of endurance training on endurance performance characteristics and cardiac autonomic modulation during night sleep were investigated. Twenty-four sedentary subjects trained over four weeks two hours per week at an average running intensity of 76+/-4% of their heart rate reserve. The R to R ECG-intervals were recorded and heart rate variability indices including high frequency power (HFP) were calculated for the nights following the training days every week. The subjects were divided into responders and non-responders according to the improvements in the maximal velocity of the incremental treadmill test (v(max)). The responders improved their v(max) by 10.9+/-46 % (p < 0.001) while no changes were observed in the non-responders (1.6+/-3.0%), although there were no differences in any training load variables between the groups. In the responders nocturnal HFP was significantly higher during the fourth training week compared to the first training week (p=0.036). Furthermore, a significant correlation was observed between the change in v(max) and the change in nocturnal HFP (r=0.482, p=0.042). It was concluded that after similar training, an increase in cardiac vagal modulation was related to improved v(max) in the sedentary subjects. Georg Thieme Verlag KG Stuttgart.New York.

The Impact of Early Life Stress on Growth and Cardiovascular Risk: A Possible Example for Autonomic Imprinting?

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Buchhorn, Reiner; Meint, Sebastian; Willaschek, Christian

2016-01-01

Early life stress is imprinting regulatory properties with life-long consequences. We investigated heart rate variability in a group of small children with height below the third percentile, who experienced an episode of early life stress due to heart failure or intra uterine growth retardation. These children appear to develop autonomic dysfunction in later life. Compared to the healthy control group heart rate variability (HRV) is reduced on average in a group of 101 children with short stature. Low HRV correlates to groups of children born small for gestational age (SGA), children with cardiac growth failure and children with congenital syndromes, but not to those with constitutional growth delay (CGD), who had normal HRV. Reduced HRV indicated by lower RMSSD and High Frequency (HF)-Power is indicating reduced vagal activity as a sign of autonomic imbalance. It is not short stature itself, but rather the underlying diseases that are the cause for reduced HRV in children with height below the third percentile. These high risk children-allocated in the groups with an adverse autonomic imprinting in utero or infancy (SGA, congenital heart disease and congenital syndromes)-have the highest risk for 'stress diseases' such as cardiovascular disease in later life. The incidence of attention deficit disorder is remarkably high in our group of short children.

The role of cardiac vagal tone and inhibitory control in pre-schoolers' listening comprehension.

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Scrimin, Sara; Patron, Elisabetta; Florit, Elena; Palomba, Daniela; Mason, Lucia

2017-12-01

This study investigated the role of basal cardiac activity and inhibitory control at the beginning of the school year in predicting oral comprehension at the end of the year in pre-schoolers. Forty-three, 4-year-olds participated in the study. At the beginning of the school year children's electrocardiogram at rest was registered followed by the assessment of inhibitory control as well as verbal working memory and verbal ability. At the end of the year all children were administered a listening comprehension ability measure. A stepwise regression showed a significant effect of basal cardiac vagal tone in predicting listening comprehension together with inhibitory control and verbal ability. These results are among the first to show the predictive role of basal cardiac vagal tone and inhibitory control in pre-schoolers' oral text comprehension, and offer new insight into the association between autonomic regulation of the heart, inhibitory control, and cognitive activity at a young age. © 2017 Wiley Periodicals, Inc.

Extreme challenges on cardiovascular control during gravity transitions

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Verheyden, B.; Beckers, F.; Aubert, A. E.

Introduction. During parabolic flights transient periods of hypergravity and microgravity are created. These periods cause translocations of bodily fluids in the longitudinal axis of the body, leading to altered cardiac preload and afterload. These extreme orthostatic challenges provide a unique platform to study baroreflex-mediated responses of the cardiovascular autonomic control system. This might have important features for the development of a model of cardiovascular deconditioning that is observed in a variety of patient populations. Purpose. Until now, due to methodological restrictions, most studies have been concentrating on the analysis of cardiovascular variability in time domain. The purpose of this study is to evaluate heart rate variability (HRV) and blood pressure variability (BPV) simultaneously, using frequency domain analysis techniques (low frequency power (LF: 0.04-0.15 Hz); high frequency power (HF: 0.16-0.4 Hz)), providing additional information about cardiac and vasomotor sympathetic modulation during gravity transitions. Methods. 12 healthy non-medicated volunteers (age = 24 ± 2.5 yr) underwent continuous ECG and blood pressure (BP) recordings during the 32nd and 34th parabolic flight campaign organized by ESA. The subjects performed 15 parabolas in supine and 15 parabolas in standing position. 5 transient gravity phases were abstracted; phase 1 and 5: before and after the parabola (1G); phase 2 and 4: at the ascending and descending leg of the parabola (2G); phase 3: at the apex of the parabola (0g). Phase 2, 3 and 4 last 20 seconds. Results. No significant differences were found in HRV and BPV parameters in supine position between the different gravity phases. In standing position, mean RR- interval was higher during 0G (900 ± 103 ms) compared to 1G (700 ± 87 ms) and 2G (600 ± 94 ms). Mean arterial BP remained relatively constant during 0G but tended to decrease during 2G (102 ± 2 mmHg vs. 105 ± 3 mmHg). Positive correlations were

Daith Piercing in a Case of Chronic Migraine: A Possible Vagal Modulation

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Angelo Cascio Rizzo

2017-11-01

Full Text Available Daith piercing is an ear piercing located at the crus of the helix, bilaterally. It is getting great consent on social media as alternative treatment in chronic migraine. No data about its efficacy and action are available in scientific literature so far. We present the case of a 54-year-old male patient suffering from refractory chronic migraine with medication-overuse, who substantially improved after bilateral ear daith piercing. His migraine was refractory to symptomatic as well as prophylactic therapies. He used to treat headaches with up to five symptomatic drugs per attack and had attempted several pharmacological preventive therapies, including Onabotulinumtoxin A. He also underwent detoxification treatments with intravenous steroids and diazepam, without durable benefit. At the time of daith piercing, the headache-related disability measures showed a HIT-6 score of 64, a MIDAS-score of 70, and a 11-point Box scale of 5. On his own free will, he decided to get a “daith piercing.” After that, he experienced a reduction of migraine attacks, which became very rare, and infrequent, less disabling episodes of tension-type headache (HIT-6 score of 56; MIDAS score of 27, 11-point Box scale of 3. Painkiller assumption has much decreased: he takes only one tablet of indomethacin 50 mg to treat tensive headaches, about four times per month. Beyond a placebo effect, we can speculate a vagal modulation as the action mechanism of daith piercing: a nociceptive sensory stimulus applied to trigeminal and vagal areas of the ear can activate ear vagal afferents, which can modulate pain pathways by means of projections to the caudal trigeminal nucleus, to the locus coeruleus and to the nucleus raphe magnus. Currently, daith piercing cannot be recommended as migraine treatment because of the lack of scientific evidence, the unquantified rate of failure and the associated risks with insertion. However, given the increasing but anecdotal evidence, we

The effect of vagal nerve blockade using electrical impulses on glucose metabolism in nondiabetic subjects

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Sathananthan M

2014-07-01

Full Text Available Matheni Sathananthan,1 Sayeed Ikramuddin,2 James M Swain,3,6 Meera Shah,1 Francesca Piccinini,4 Chiara Dalla Man,4 Claudio Cobelli,4 Robert A Rizza,1 Michael Camilleri,5 Adrian Vella1 1Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, USA; 2Division of General Surgery, University of Minnesota, Minneapolis, MN, USA; 3Division of General Surgery, Mayo Clinic College of Medicine, Rochester, MN, USA; 4Department of Information Engineering, University of Padua, Padua, Italy; 5Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN, USA; 6Scottsdale Healthcare Bariatric Center, Scottsdale, AZ, USA Purpose: Vagal interruption causes weight loss in humans and decreases endogenous glucose production in animals. However, it is unknown if this is due to a direct effect on glucose metabolism. We sought to determine if vagal blockade using electrical impulses alters glucose metabolism in humans. Patients and methods: We utilized a randomized, cross-over study design where participants were studied after 2 weeks of activation or inactivation of vagal nerve blockade (VNB. Seven obese subjects with impaired fasting glucose previously enrolled in a long-term study to examine the effect of VNB on weight took part. We used a standardized triple-tracer mixed meal to enable measurement of the rate of meal appearance, endogenous glucose production, and glucose disappearance. The 550 kcal meal was also labeled with 111In-diethylene triamine pentaacetic acid (DTPA to measure gastrointestinal transit. Insulin action and ß-cell responsivity indices were estimated using the minimal model. Results: Integrated glucose, insulin, and glucagon concentrations did not differ between study days. This was also reflected in a lack of effect on β-cell responsivity and insulin action. Furthermore, fasting and postprandial endogenous glucose production, integrated meal appearance, and glucose

Hopelessness is associated with decreased heart rate variability during championship chess games.

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Schwarz, Alfons M; Schächinger, Hartmut; Adler, Rolf H; Goetz, Stefan M

2003-01-01

Clinical observations suggest that negative affects such as helplessness/hopelessness (HE/HO) may induce autonomic duration; affects were assessed for every move after reconstruction of the games. In all games compiled, 18 situation of intense confidence/optimism and 20 of intense helplessness/hopelessness were observed. Intense affects of HE/HO were associated with decreasing HF-HRV (Fisher exact test, p =.003), increasing "nervousness" (p =.0005), decreasing "optimism" (p =.0005), and decreasing "calmness" (p =.0005). Investigation of championship chess game players with an ELO strength > or = 2300 in a natural field setting revealed increasing HE/HO being associated with reduced HF-HRV suggestive of vagal withdrawal. Thus, our data may help link negative mood states, autonomic nervous system disturbances, and cardiac events.

Duodenal activation of cAMP-dependent protein kinase induces vagal afferent firing and lowers glucose production in rats.

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Rasmussen, Brittany A; Breen, Danna M; Luo, Ping; Cheung, Grace W C; Yang, Clair S; Sun, Biying; Kokorovic, Andrea; Rong, Weifang; Lam, Tony K T

2012-04-01

The duodenum senses nutrients to maintain energy and glucose homeostasis, but little is known about the signaling and neuronal mechanisms involved. We tested whether duodenal activation of adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase A (PKA) is sufficient and necessary for cholecystokinin (CCK) signaling to trigger vagal afferent firing and regulate glucose production. In rats, we selectively activated duodenal PKA and evaluated changes in glucose kinetics during the pancreatic (basal insulin) pancreatic clamps and vagal afferent firing. The requirement of duodenal PKA signaling in glucose regulation was evaluated by inhibiting duodenal activation of PKA in the presence of infusion of the intraduodenal PKA agonist (Sp-cAMPS) or CCK1 receptor agonist (CCK-8). We also assessed the involvement of a neuronal network and the metabolic impact of duodenal PKA activation in rats placed on high-fat diets. Intraduodenal infusion of Sp-cAMPS activated duodenal PKA and lowered glucose production, in association with increased vagal afferent firing in control rats. The metabolic and neuronal effects of duodenal Sp-cAMPS were negated by coinfusion with either the PKA inhibitor H89 or Rp-CAMPS. The metabolic effect was also negated by coinfusion with tetracaine, molecular and pharmacologic inhibition of NR1-containing N-methyl-d-aspartate (NMDA) receptors within the dorsal vagal complex, or hepatic vagotomy in rats. Inhibition of duodenal PKA blocked the ability of duodenal CCK-8 to reduce glucose production in control rats, whereas duodenal Sp-cAMPS bypassed duodenal CCK resistance and activated duodenal PKA and lowered glucose production in rats on high-fat diets. We identified a neural glucoregulatory function of duodenal PKA signaling. Copyright © 2012 AGA Institute. Published by Elsevier Inc. All rights reserved.

Anterograde Tracing Method using DiI to Label Vagal Innervation of the Embryonic and Early Postnatal Mouse Gastrointestinal Tract

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Murphy, Michelle C.; Fox, Edward A.

2007-01-01

The mouse is an extremely valuable model for studying vagal development in relation to strain differences, genetic variation, gene manipulations, or pharmacological manipulations. Therefore, a method using 1, 1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI) was developed for labeling vagal innervation of the gastrointestinal (GI) tract in embryonic and postnatal mice. DiI labeling was adapted and optimized for this purpose by varying several facets of the method. For example, insertion and crushing of DiI crystals into the nerve led to faster DiI diffusion along vagal axons and diffusion over longer distances as compared with piercing the nerve with a micropipette tip coated with dried DiI oil. Moreover, inclusion of EDTA in the fixative reduced leakage of DiI out of nerve fibers that occurred with long incubations. Also, mounting labeled tissue in PBS was superior to glycerol with n-propyl gallate, which resulted in reduced clarity of DiI labeling that may have been due to DiI leaking out of fibers. Optical sectioning of flattened wholemounts permitted examination of individual tissue layers of the GI tract wall. This procedure aided identification of nerve ending types because in most instances each type innervates a different tissue layer. Between embryonic day 12.5 and postnatal day 8, growth of axons into the GI tract, formation and patterning of fiber bundles in the myenteric plexus and early formation of putative afferent and efferent nerve terminals were observed. Thus, the DiI tracing method developed here has opened up a window for investigation during an important phase of vagal development. PMID:17418900

Association between depression and heart rate variability in patients after cardiac surgery: a pilot study.

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Patron, Elisabetta; Messerotti Benvenuti, Simone; Favretto, Giuseppe; Valfrè, Carlo; Bonfà, Carlotta; Gasparotto, Renata; Palomba, Daniela

2012-07-01

Depression is a risk factor for cardiovascular diseases. Reduced heart rate variability (HRV), which reflects altered autonomic nervous system activity, has been suggested as one of the mechanisms linking depression to cardiovascular diseases. However, the relationship between depression and HRV has not yet been investigated in patients undergone cardiac surgery. Therefore, the main aim of this study was to examine whether postoperative depression could be related to reduced HRV. Eleven patients with depression and 22 patients without depression, who had undergone cardiac surgery, were enrolled postoperatively. In all patients, HRV was derived from a four-minute blood volume pulse recording at rest. Analyses of covariance and partial correlations, while controlling for anxiety, were used to examine the associations between postoperative depression and each HRV parameter. Compared to non-depressed patients, patients with depression showed significantly lower standard deviation of N-to-N intervals (SDNN) (p=.02), root mean square successive difference of N-to-N intervals (rMSSD) (p=.001), and high-frequency power (p=.002). Partial correlation analyses showed that depression was inversely related to SDNN (r=-.49, p=.005), rMSSD (r=-.58, p=.001), and high-frequency power (r=-.41, p=.02), whereas it was unrelated to other HRV parameters (p's>.09). The current findings extend the depression-reduced HRV relationship to the patients after cardiac surgery. Also, our study suggests that postoperative depression is more likely to be associated with reduced vagal modulation on the heart than with excessive sympathetic activity. Copyright © 2012 Elsevier Inc. All rights reserved.

Non-stationarities significantly distort short-term spectral, symbolic and entropy heart rate variability indices

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Magagnin, Valentina; Bassani, Tito; Bari, Vlasta; Turiel, Maurizio; Porta, Alberto; Maestri, Roberto; Pinna, Gian Domenico

2011-01-01

The autonomic regulation is non-invasively estimated from heart rate variability (HRV). Many methods utilized to assess autonomic regulation require stationarity of HRV recordings. However, non-stationarities are frequently present even during well-controlled experiments, thus potentially biasing HRV indices. The aim of our study is to quantify the potential bias of spectral, symbolic and entropy HRV indices due to non-stationarities. We analyzed HRV series recorded in healthy subjects during uncontrolled daily life activities typical of 24 h Holter recordings and during predetermined levels of robotic-assisted treadmill-based physical exercise. A stationarity test checking the stability of the mean and variance over short HRV series (about 300 cardiac beats) was utilized to distinguish stationary periods from non-stationary ones. Spectral, symbolic and entropy indices evaluated solely over stationary periods were contrasted with those derived from all the HRV segments. When indices were calculated solely over stationary series, we found that (i) during both uncontrolled daily life activities and controlled physical exercise, the entropy-based complexity indices were significantly larger; (ii) during uncontrolled daily life activities, the spectral and symbolic indices linked to sympathetic modulation were significantly smaller and those associated with vagal modulation were significantly larger; (iii) while during uncontrolled daily life activities, the variance of spectral, symbolic and entropy rate indices was significantly larger, during controlled physical exercise, it was smaller. The study suggests that non-stationarities increase the likelihood to overestimate the contribution of sympathetic control and affect the power of statistical tests utilized to discriminate conditions and/or groups

Vagal Nerve Stimulator Malfunction with Change in Neck Position: Case Report and Literature Review.

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D'Agostino, Erin; Makler, Vyacheslav; Bauer, David F

2018-06-01

Vagal nerve stimulation is a safe and well-tolerated treatment for drug-resistant epilepsy. Complications and failure of the device can result from lead fracture, device malfunction, disconnection, or battery displacement and can result in a variety of symptoms. We present an interesting case of stimulator malfunction with increased impedance change seen only with a change in head position. The patient is a 25-year-old male with a vagal nerve stimulator (VNs) placed for medically refractory epilepsy who presented with neck pain and an electrical pulling sensation in his neck whenever he turned his head to the right. Initial interrogation of the VNs showed normal impedance. Subsequent interrogation with the patient's head turned found increased impedance only when the head was turned to the right. The patient had successful removal and replacement of the device with resolution of his preoperative complaints. Partial lead fracture was seen at explant. VNs malfunction can present in atypical ways. Positional maneuvers may help with its timely diagnosis. Copyright © 2018 Elsevier Inc. All rights reserved.

Investigating the use of pre-training measures of autonomic regulation for assessing functional overreaching in endurance athletes.

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Coates, Alexandra M; Hammond, Sarah; Burr, Jamie F

2018-04-10

The use of heart rate variability (HRV) to inform daily training prescription is becoming common in endurance sport. Few studies, however, have investigated the use of pre-training HRV to predict decreased performance or altered exercising autonomic response, typical of functional overreaching (FOR). Further, a new cardiac vagal tone (ProCVT) technology purports to eliminate some of the noise associated with daily HRV, and therefore may be better at predicting same-day performance. The purpose of this investigation was to examine if changes to resting HRV and ProCVT were associated with alterations in performance, maximal heart rate (HRmax), or heart rate recovery (HRrec) in FOR athletes. Twenty-eight recreational cyclists and triathletes were assigned to experimental/control conditions and underwent: 1 week of reduced training, 3 weeks of overload (OL) or regular training (CON), and 1 week of recovery. Testing occurred following the reduced training week (T1), post-3 weeks of training (T2), and following the recovery week (T3). Measures of resting HRV/ProCVT were collected each testing session, followed by maximal incremental exercise tests with HRrec taken 60 s post-exercise. Performance decreased from T1 to T2 in the OL group vs. CON (Δ-9 ± 12 vs. Δ9 ± 11 W, P HRV and ProCVT did not change in either group. Same-day resting autonomic measures are insufficient in predicting alterations to performance or exercising HR measures following overload training.

Chronic intermittent hypoxia-hypercapnia blunts heart rate responses and alters neurotransmission to cardiac vagal neurons.

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Dyavanapalli, Jhansi; Jameson, Heather; Dergacheva, Olga; Jain, Vivek; Alhusayyen, Mona; Mendelowitz, David

2014-07-01

Patients with obstructive sleep apnoea experience chronic intermittent hypoxia-hypercapnia (CIHH) during sleep that elicit sympathetic overactivity and diminished parasympathetic activity to the heart, leading to hypertension and depressed baroreflex sensitivity. The parasympathetic control of heart rate arises from pre-motor cardiac vagal neurons (CVNs) located in nucleus ambiguus (NA) and dorsal motor nucleus of the vagus (DMNX). The mechanisms underlying diminished vagal control of heart rate were investigated by studying the changes in blood pressure, heart rate, and neurotransmission to CVNs evoked by acute hypoxia-hypercapnia (H-H) and CIHH. In vivo telemetry recordings of blood pressure and heart rate were obtained in adult rats during 4 weeks of CIHH exposure. Retrogradely labelled CVNs were identified in an in vitro brainstem slice preparation obtained from adult rats exposed either to air or CIHH for 4 weeks. Postsynaptic inhibitory or excitatory currents were recorded using whole cell voltage clamp techniques. Rats exposed to CIHH had increases in blood pressure, leading to hypertension, and blunted heart rate responses to acute H-H. CIHH induced an increase in GABAergic and glycinergic neurotransmission to CVNs in NA and DMNX, respectively; and a reduction in glutamatergic neurotransmission to CVNs in both nuclei. CIHH blunted the bradycardia evoked by acute H-H and abolished the acute H-H evoked inhibition of GABAergic transmission while enhancing glycinergic neurotransmission to CVNs in NA. These changes with CIHH inhibit CVNs and vagal outflow to the heart, both in acute and chronic exposures to H-H, resulting in diminished levels of cardioprotective parasympathetic activity to the heart as seen in OSA patients. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

A pilot investigation of the effect of extremely low frequency pulsed electromagnetic fields on humans' heart rate variability.

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Baldi, Emilio; Baldi, Claudio; Lithgow, Brian J

2007-01-01

The question whether pulsed electromagnetic field (PEMF) can affect the heart rhythm is still controversial. This study investigates the effects on the cardiocirculatory system of ELF-PEMFs. It is a follow-up to an investigation made of the possible therapeutic effect ELF-PEMFs, using a commercially available magneto therapeutic unit, had on soft tissue injury repair in humans. Modulation of heart rate (HR) or heart rate variability (HRV) can be detected from changes in periodicity of the R-R interval and/or from changes in the numbers of heart-beat/min (bpm), however, R-R interval analysis gives only a quantitative insight into HRV. A qualitative understanding of HRV can be obtained considering the power spectral density (PSD) of the R-R intervals Fourier transform. In this study PSD is the investigative tool used, more specifically the low frequency (LF) PSD and high frequency (HF) PSD ratio (LF/HF) which is an indicator of sympatho-vagal balance. To obtain the PSD value, variations of the R-R time intervals were evaluated from a continuously recorded ECG. The results show a HR variation in all the subjects when they are exposed to the same ELF-PEMF. This variation can be detected by observing the change in the sympatho-vagal equilibrium, which is an indicator of modulation of heart activity. Variation of the LF/HF PSD ratio mainly occurs at transition times from exposure to nonexposure, or vice versa. Also of interest are the results obtained during the exposure of one subject to a range of different ELF-PEMFs. This pilot study suggests that a full investigation into the effect of ELF-PEMFs on the cardiovascular system is justified.

Hypothesis: Low frequency heart rate variability (LF-HRV) is an input for undisclosed yet biological adaptive control, governing the cardiovascular regulations to assure optimal functioning.

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Gabbay, Uri; Bobrovsky, Ben Zion

2012-02-01

Cardiovascular regulation is considered today as having three levels: autoregulations, neural regulations and hormonal regulations. We hypothesize that the cardiovascular regulation has an additional (fourth) control level which is outer, hierarchical (adaptive) loop where LF-HRV amplitude serves as a reference input which the neural cardiovascular center detects and responses in order to maintain LF-HRV around some prescribed level. Supporting evidences: LF-HRV absence during artificial cardiac pacing may be associated with "pacemaker syndrome" which had not been sufficiently understood regardless of apparently unimpaired cardiovascular performance. The hypothesis may provide an essential basis for understanding several cardiovascular morbidities and insight toward diagnostic measures and treatments (including but not limited to adding variability to the pulse generator of artificial pacemakers to eliminate "pace maker syndrome"). Copyright © 2011 Elsevier Ltd. All rights reserved.

Resting heart rate variability predicts safety learning and fear extinction in an interoceptive fear conditioning paradigm.

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Meike Pappens

Full Text Available This study aimed to investigate whether interindividual differences in autonomic inhibitory control predict safety learning and fear extinction in an interoceptive fear conditioning paradigm. Data from a previously reported study (N = 40 were extended (N = 17 and re-analyzed to test whether healthy participants' resting heart rate variability (HRV - a proxy of cardiac vagal tone - predicts learning performance. The conditioned stimulus (CS was a slight sensation of breathlessness induced by a flow resistor, the unconditioned stimulus (US was an aversive short-lasting suffocation experience induced by a complete occlusion of the breathing circuitry. During acquisition, the paired group received 6 paired CS-US presentations; the control group received 6 explicitly unpaired CS-US presentations. In the extinction phase, both groups were exposed to 6 CS-only presentations. Measures included startle blink EMG, skin conductance responses (SCR and US-expectancy ratings. Resting HRV significantly predicted the startle blink EMG learning curves both during acquisition and extinction. In the unpaired group, higher levels of HRV at rest predicted safety learning to the CS during acquisition. In the paired group, higher levels of HRV were associated with better extinction. Our findings suggest that the strength or integrity of prefrontal inhibitory mechanisms involved in safety- and extinction learning can be indexed by HRV at rest.

Anxiety disorders are associated with reduced heart rate variability: A meta-analysis

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John eChalmers

2014-07-01

Full Text Available Background: Anxiety disorders increase risk of future cardiovascular disease (CVD and mortality, even after controlling for confounds including smoking, lifestyle, and socioeconomic status, and irrespective of a history of medical disorders. While impaired vagal function, indicated by reductions in heart rate variability (HRV, may be one mechanism linking anxiety disorders to CVD, prior studies have reported inconsistent findings highlighting the need for meta-analysis.Method: Studies comparing resting state HRV recordings in patients with an anxiety disorder as a primary diagnosis and healthy controls were considered for meta-analysis. Results: Meta-analyses were based on 36 articles, including 2086 patients with an anxiety disorder and 2294 controls. Overall, anxiety disorders were characterised by lower HRV (high frequency: Hedges’ g = -.29. 95%CI: -.41 to -.17, p < 0.001; time domain: Hedges’ g = -0.45, 95%CI: -0.57 to -0.33, p < .001 than controls. Panic Disorder (n=447, Post-Traumatic Stress Disorder (n=192, Generalized Anxiety Disorder (n=68, and Social anxiety disorder (n=90, but not Obsessive Compulsive Disorder (n=40, displayed reductions in high frequency HRV relative to controls (all ps < .001. Conclusions: Anxiety disorders are associated with reduced HRV, findings associated with a small to moderate effect size. Findings have important implications for future physical health and wellbeing of patients, highlighting a need for comprehensive cardiovascular risk reduction.

Effect of weight loss on sympatho-vagal balance in subjects with grade-3 obesity: restrictive surgery versus hypocaloric diet.

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Pontiroli, Antonio E; Merlotti, Claudia; Veronelli, Annamaria; Lombardi, Federico

2013-12-01

Few and mostly uncontrolled studies indicate that weight loss improves heart rate variability (HRV) in grade-3 obesity. The aim of this study was to compare in grade-3 obesity surgery and hypocaloric diet on clinical and metabolic variables and on autonomic indices of HRV. Twenty-four subjects (body mass index, BMI 45.5 ± 9.13 kg/m(2)) underwent surgery (n = 12, gastric banding, LAGB) or received hypocaloric diet (n = 12, 1,000-1,200 kg/day). Clinical [BMI, systolic blood pressure (SBP) and diastolic blood pressure (DBP), heart rate] and metabolic variables [glucose, cholesterol, HDL- and LDL-cholesterol, triglycerides, AST and ALT transaminases] and 24-h Holter electrocardiographic-derived HRV parameters [R-R interval, standard deviation of R-R intervals (SDNN); low/high-frequency (LF/HF) ratio, and QT interval] were measured at baseline and after 6 months. The two groups were identical at baseline. BMI (-7.5 ± 3.57 kg/m(2), mean ± SD), glucose (-24.1 ± 26.77 mg/dL), SBP (-16.7 ± 22.19 mmHg) and DBP (-6.2 ± 8.56 mmHg) decreased in LAGB subjects (p < 0.05) and remained unchanged in controls. At 6 months, SDNN increased in LAGB subjects (+25.0 ± 37.19 ms, p < 0.05) and LF/HF ratio diminished (2.9 ± 1.84 vs. 4.9 ± 2.78; p = 0.01), with no change in controls; LF (daytime) and HF (24 h and daytime) increased in LAGB subjects, with no change in controls. Decrease in BMI correlated with SBP and DBP decrease (p < 0.05), and DBP decrease correlated with HR decrease (p < 0.05) and QT shortening (p < 0.05). Weight loss is associated with improvement of glucose metabolism, of blood pressure, and with changes in time and frequency domain parameters of HRV; all these changes indicate recovery of a more physiological autonomic control, with increase in parasympathetic and reduction in sympathetic indices of HRV.

Cardiac autonomic function during sleep: effects of alcohol dependence and evidence of partial recovery with abstinence.

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de Zambotti, Massimiliano; Willoughby, Adrian R; Baker, Fiona C; Sugarbaker, David S; Colrain, Ian M

2015-06-01

Chronic alcoholism is associated with the development of cardiac and peripheral autonomic nervous system (ANS) pathology. The aim of the present study was to evaluate the extent to which recovery in ANS function could be demonstrated over the first 4 months of abstinence. Fifteen alcoholics (7 women) were studied on three occasions: within a month of detoxification, at approximately 2 months post-detox, and at 4 months post-detox. Thirteen control subjects (6 women) were also studied on three occasions with inter-study intervals matching those of the alcoholics. Six alcoholics relapsed, 48.7 ± 27.9 days following the initial PSG session. ANS function was assessed in the first part of stable non-rapid eye movement sleep. Frequency-domain power spectral analysis of heart rate variability (HRV) produced variables including: heart rate (HR), total power (TP; an index representing total HR variability), High Frequency power (HFa; an index reflecting cardiac vagal modulation), HF proportion of total power (HFprop sympathovagal balance), and HF peak frequency (HFpf; an index reflecting respiration rate). Overall, high total and high frequency variability and low sympathovagal balance and myocardial contractility are considered as desired conditions to promote cardiovascular health. At initial assessment, alcoholics had a higher HR (p < 0.001) and respiratory rate (p < 0.01), and lower vagal activity (HFa; p < 0.01) than controls. Alcoholics showed evidence of recovery in HR (p = 0.039) and HFa (p = 0.031) with 4 months of abstinence. Alcoholics with higher TP at the initial visit showed a greater improvement in TP from the initial to the 4 month follow-up session (r = 0.75, p < 0.05). Alcoholics showed substantial recovery in HR and vagal modulation of HRV with 4 months of abstinence, with evidence that the extent of recovery in HRV may be partially determined by the extent of alcohol dependence-related insult to the cardiac ANS system. These data support other studies

An approach to contouring the dorsal vagal complex for radiotherapy planning

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O' Steen, Lillie; Amdur, Robert J., E-mail: amdurr@shands.ufl.edu

2016-04-01

Multiple studies suggest that radiation dose to the area of the brainstem called the “dorsal vagal complex (DVC)” influences the frequency of nausea and vomiting during radiotherapy. The purpose of this didactic article is to describe the step-by-step process that we use to contour the general area of the DVC on axial computed tomography (CT) images as would be done for radiotherapy planning. The contouring procedure that we describe for contouring the area of the DVC is useful to medical dosimetrists and radiation oncologists.

Cardiac autonomic control in adolescents with primary hypertension

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Havlíceková Z

2009-12-01

Full Text Available Abstract Background Impairment in cardiovascular autonomic regulation participates in the onset and maintenance of primary hypertension. Objective The aim of the present study was to evaluate cardiac autonomic control using long-term heart rate variability (HRV analysis in adolescents with primary hypertension. Subjects and methods Twenty two adolescent patients with primary hypertension (5 girls/17 boys aged 14-19 years and 22 healthy subjects matched for age and gender were enrolled. Two periods from 24-hour ECG recording were evaluated by HRV analysis: awake state and sleep. HRV analysis included spectral power in low frequency band (LF, in high frequency band (HF, and LF/HF ratio. Results In awake state, adolescents with primary hypertension had lower HF and higher LF and LF/HF ratio. During sleep, HF was lower and LF/HF ratio was higher in patients with primary hypertension. Conclusions A combination of sympathetic predominance and reduced vagal activity might represent a potential link between psychosocial factors and primary hypertension, associated with increased cardiovascular morbidity.

Sex differences in autonomic function following maximal exercise.

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Kappus, Rebecca M; Ranadive, Sushant M; Yan, Huimin; Lane-Cordova, Abbi D; Cook, Marc D; Sun, Peng; Harvey, I Shevon; Wilund, Kenneth R; Woods, Jeffrey A; Fernhall, Bo

2015-01-01

Heart rate variability (HRV), blood pressure variability, (BPV) and heart rate recovery (HRR) are measures that provide insight regarding autonomic function. Maximal exercise can affect autonomic function, and it is unknown if there are sex differences in autonomic recovery following exercise. Therefore, the purpose of this study was to determine sex differences in several measures of autonomic function and the response following maximal exercise. Seventy-one (31 males and 40 females) healthy, nonsmoking, sedentary normotensive subjects between the ages of 18 and 35 underwent measurements of HRV and BPV at rest and following a maximal exercise bout. HRR was measured at minute one and two following maximal exercise. Males have significantly greater HRR following maximal exercise at both minute one and two; however, the significance between sexes was eliminated when controlling for VO2 peak. Males had significantly higher resting BPV-low-frequency (LF) values compared to females and did not significantly change following exercise, whereas females had significantly increased BPV-LF values following acute maximal exercise. Although males and females exhibited a significant decrease in both HRV-LF and HRV-high frequency (HF) with exercise, females had significantly higher HRV-HF values following exercise. Males had a significantly higher HRV-LF/HF ratio at rest; however, both males and females significantly increased their HRV-LF/HF ratio following exercise. Pre-menopausal females exhibit a cardioprotective autonomic profile compared to age-matched males due to lower resting sympathetic activity and faster vagal reactivation following maximal exercise. Acute maximal exercise is a sufficient autonomic stressor to demonstrate sex differences in the critical post-exercise recovery period.

Resting state connectivity of the medial prefrontal cortex covaries with individual differences in high-frequency heart rate variability.

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Jennings, J Richard; Sheu, Lei K; Kuan, Dora C-H; Manuck, Stephen B; Gianaros, Peter J

2016-04-01

Resting high-frequency heart rate variability (HF-HRV) relates to cardiac vagal control and predicts individual differences in health and longevity, but its functional neural correlates are not well defined. The medial prefrontal cortex (mPFC) encompasses visceral control regions that are components of intrinsic networks of the brain, particularly the default mode network (DMN) and the salience network (SN). Might individual differences in resting HF-HRV covary with resting state neural activity in the DMN and SN, particularly within the mPFC? This question was addressed using fMRI data from an eyes-open, 5-min rest period during which echoplanar brain imaging yielded BOLD time series. Independent component analysis yielded functional connectivity estimates defining the DMN and SN. HF-HRV was measured in a rest period outside of the scanner. Midlife (52% female) adults were assessed in two studies (Study 1, N = 107; Study 2, N = 112). Neither overall DMN nor SN connectivity strength was related to HF-HRV. However, HF-HRV related to connectivity of one region within mPFC shared by the DMN and SN, namely, the perigenual anterior cingulate cortex, an area with connectivity to other regions involved in autonomic control. In sum, HF-HRV does not seem directly related to global resting state activity of intrinsic brain networks, but rather to more localized connectivity. A mPFC region was of particular interest as connectivity related to HF-HRV was shared by the DMN and SN. These findings may indicate a functional basis for the coordination of autonomic cardiac control with engagement and disengagement from the environment. © 2015 Society for Psychophysiological Research.

Structural remodeling of the heart and its premotor cardioinhibitory vagal neurons following T(5) spinal cord transection.

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Lujan, Heidi L; Janbaih, Hussein; DiCarlo, Stephen E

2014-05-01

Midthoracic spinal cord injury (SCI) is associated with enhanced cardiac sympathetic activity and reduced cardiac parasympathetic activity. The enhanced cardiac sympathetic activity is associated with sympathetic structural plasticity within the stellate ganglia, spinal cord segments T1-T4, and heart. However, changes to cardiac parasympathetic centers rostral to an experimental SCI are relatively unknown. Importantly, reduced vagal activity is a predictor of high mortality. Furthermore, this autonomic dysregulation promotes progressive left ventricular (LV) structural remodeling. Accordingly, we hypothesized that midthoracic spinal cord injury is associated with structural plasticity in premotor (preganglionic parasympathetic neurons) cardioinhibitory vagal neurons located within the nucleus ambiguus as well as LV structural remodeling. To test this hypothesis, dendritic arborization and morphology (cholera toxin B immunohistochemistry and Sholl analysis) of cardiac projecting premotor cardioinhibitory vagal neurons located within the nucleus ambiguus were determined in intact (sham transected) and thoracic level 5 transected (T5X) rats. In addition, LV chamber size, wall thickness, and collagen content (Masson trichrome stain and structural analysis) were determined. Midthoracic SCI was associated with structural changes within the nucleus ambiguus and heart. Specifically, following T5 spinal cord transection, there was a significant increase in cardiac parasympathetic preganglionic neuron dendritic arborization, soma area, maximum dendritic length, and number of intersections/animal. This parasympathetic structural remodeling was associated with a profound LV structural remodeling. Specifically, T5 spinal cord transection increased LV chamber area, reduced LV wall thickness, and increased collagen content. Accordingly, results document a dynamic interaction between the heart and its parasympathetic innervation.

Spectral Parameters of HRV In Yoga Practitioners, Athletes And Sedentary Males.

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Peter, Rosemary; Sood, Sushma; Dhawan, Ashwani

2015-01-01

Physical inactivity is an important risk factor for cardiovascular mortality and morbidity. Exercise is considered an acceptable method for improving and maintaining physical and emotional health. Although yoga is historically a spiritual discipline, a growing body of evidence supports the belief that yoga benefits physical and mental health. The objective of this study was to evaluate heart rate variability which reflects autonomic control of heart among yoga practitioners, athletes and individuals with sedentary lifestyle. The study was carried out in the departments of physiology at MAMC Agroha, Hisar and Pt. BD Sharma PGIMS Rohtak, Haryana. The study group comprised of 1200 healthy male volunteers of 16 to 55 years of age. The study group was divided into four age groups: Group A of age 16 to 25 years; Group B of age 26 to 35 years; Group C of age 36 to 45 years and Group D of age 46 to 55 years. All age groups were further divided into three categories i.e athlete (runner), yoga (yoga practitioners) and sedentary in which individuals with sedentary life style were included. The basal recording of ECG in lead II was done for 5 minutes. The Polyrite-D ECG data was used for analysis of heart rate variability by frequency domain method. Two spectral components were recorded namely high frequency (HF) component (0.15-0.4 Hz), an indicator of vagal efferent activity and low frequency (LF) component (0.04-.15 Hz), replicator of composite sympatho-vagal interplay. HF component in normalized unit was found significantly high in age group B and C in yoga practitioners and athletes as compared to sedentary individuals and in age group D significantly high in yoga practitioners as compared to athletes and sedentary individuals. Significantly decreased LF/HF ratio was found in age group B and C in yoga and athlete subjects as compared to sedentary individuals and in age group D in yoga practitioners as compared to athletes and sedentary individuals. This indicates that

Cardiorespiratory and cardiac autonomic responses to 30-15 intermittent fitness test in team sport players.

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Buchheit, Martin; Al Haddad, Hani; Millet, Grégoire Paul; Lepretre, Pierre Marie; Newton, Michael; Ahmaidi, Said

2009-01-01

The 30-15 Intermittent Fitness Test (30-15IFT) is an attractive alternative to classic continuous incremental field tests for defining a reference velocity for interval training prescription in team sport athletes. The aim of the present study was to compare cardiorespiratory and autonomic responses to 30-15IFT with those observed during a standard continuous test (CT). In 20 team sport players (20.9 +/- 2.2 years), cardiopulmonary parameters were measured during exercise and for 10 minutes after both tests. Final running velocity, peak lactate ([La]peak), and rating of perceived exertion (RPE) were also measured. Parasympathetic function was assessed during the postexercise recovery phase via heart rate (HR) recovery time constant (HRR[tau]) and HR variability (HRV) vagal-related indices. At exhaustion, no difference was observed in peak oxygen uptake VO2peak), respiratory exchange ratio, HR, or RPE between 30-15IFT and CT. In contrast, 30-15IFT led to significantly higher minute ventilation, [La]peak, and final velocity than CT (p HRV vagal-related indices (i.e., the root mean square of successive R-R intervals differences [rMSSD]: 4.1 +/- 2.4 and 7.0 +/- 4.9 milliseconds, p < 0.05). In conclusion, the 30-15IFT is accurate for assessing VThs and VO2peak, but it alters postexercise parasympathetic function more than a continuous incremental protocol.

Analysis of the respiratory component of heart rate variability in the Cururu toad Rhinella schneideri.

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Zena, Lucas A; Leite, Cléo A C; Longhini, Leonardo S; Dias, Daniel P M; da Silva, Glauber S F; Hartzler, Lynn K; Gargaglioni, Luciane H; Bícego, Kênia C

2017-11-23

Beat-to-beat variation in heart rate (f H ) has been used as a tool for elucidating the balance between sympathetic and parasympathetic modulation of the heart. A portion of the temporal changes in f H is evidenced by a respiratory influence (cardiorespiratory interaction) on heart rate variability (HRV) with heartbeats increasing and decreasing within a respiratory cycle. Nevertheless, little is known about respiratory effects on HRV in lower vertebrates. By using frequency domain analysis, we provide the first evidence of a ventilatory component in HRV similar to mammalian respiratory sinus arrhythmia in an amphibian, the toad Rhinella schneideri. Increases in the heartbeats arose synchronously with each lung inflation cycle, an intermittent breathing pattern comprised of a series of successive lung inflations. A well-marked peak in the HRV signal matching lung inflation cycle was verified in toads whenever lung inflation cycles exhibit a regular rhythm. The cardiac beat-to-beat variation evoked at the moment of lung inflation accounts for both vagal and sympathetic influences. This cardiorespiratory interaction may arise from interactions between central and peripheral feedback mechanisms governing cardiorespiratory control and may underlie important cardiorespiratory adjustments for gas exchange improvement especially under extreme conditions like low oxygen availability.

Reliability of Heart Rate Variability in Children: Influence of Sex and Body Position During Data Collection.

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Silva, Carla Cristiane; Bertollo, Maurizio; Reichert, Felipe Fossati; Boullosa, Daniel Alexandre; Nakamura, Fábio Yuzo

2017-05-01

To examine which body position and indices present better reliability of heart rate variability (HRV) measures in children and to compare the HRV analyzed in different body positions between sexes. Twenty eutrophic prepubertal children of each sex participated in the study. The RR intervals were recorded using a portable heart rate monitor twice a day for 7 min in the supine, sitting, and standing positions. The reproducibility was analyzed using the intraclass correlation coefficient (ICC; two way mixed) and within-subject coefficient of variation (CV).Two-way ANOVA with repeated measures was used to compare the sexes. High levels of reproducibility were indicated by higher ICC in the root-mean-square difference of successive normal RR intervals (RMSSD: 0.93 and 0.94) and Poincaré plot of the short-term RR interval variability (SD1: 0.92 and 0.94) parameters for boys and girls, respectively, in the supine position. The ICCs were lower in the sitting and standing positions for all HRV indices. In addition, the girls presented significantly higher values than the boys for SDNN and absolute high frequency (HF; p position. The supine position is the most reproducible for the HRV indices in both sexes, especially the vagal related indices.

[Heart rate variability and physical exercise. Current status].

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Hottenrott, Kuno; Hoos, Olaf; Esperer, Hans Dieter

2006-09-01

Heart rate variability (HRV) has long been used in risk stratification for sudden cardiac death and diabetic autonomic neuropathy. In recent years, both time and frequency domain indices of HRV also gained increasing interest in sports and training sciences. In these fields, HRV is currently used for the noninvasive assessment of autonomic changes associated with short-term and long-term endurance exercise training in both leisure sports activity and high-performance training. Furthermore, HRV is being investigated as a diagnostic marker of overreaching and overtraining.A large body of evidence shows that, in healthy subjects and cardiovascular patients of all ages (up to an age of 70 years), regular aerobic training usually results in a significant improvement of overall as well as instantaneous HRV. These changes, which are accompanied by significant reductions in heart rates both at rest and during submaximal exercise, reflect an increase in autonomic efferent activity and a shift in favor of enhanced vagal modulation of the cardiac rhythm. Regular aerobic training of moderate volume and intensity over a minimum period of 3 months seems to be necessary to ensure these effects, which might be associated with a prognostic benefit regarding overall mortality.At present, available data does not allow for final conclusions with respect to the usefulness of traditional HRV indices in assessing an individual's exercise performance and monitoring training load. The discrepant results published so far are due to several factors including insufficient study size and design, and different HRV methods. Large-sized and prospectively designed studies are necessary for clarification. It also remains to be seen, whether the traditional HRV indices prove useful in the diagnosis of overreaching and overtraining. Preliminary results, though promising, need to be confirmed in larger cohorts.A basic problem in HRV analysis is nonstationarity of the heart rate signal, which holds

Infant diet, gender and the development of vagal tone stability during the first two years of life

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Postnatal nutrition influences neurodevelopment, including autonomic nervous system components associated with cardiac control. In this study resting vagal tone (V) was measured quarterly during infancy and at 2 years in 146 breast-fed, 143 milk formula-fed, and 137 soy formula-fed infants. Stabilit...

Coffee Consumption and Heart Rate Variability: The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) Cohort Study.

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de Oliveira, Rackel Aguiar Mendes; Araújo, Larissa Fortunato; de Figueiredo, Roberta Carvalho; Goulart, Alessandra C; Schmidt, Maria Ines; Barreto, Sandhi Maria; Ribeiro, Antonio Luiz Pinho

2017-07-13

Studies have shown that acute coffee ingestion can affect cardiovascular autonomic activity, although the chronic effects on heart rate variability (HRV) remain controversial. A cross-sectional study with baseline data (2008-2010) from ELSA-Brasil cohort of 15,105 (aged 35-74), based in six Brazilian states. Coffee consumption in the previous 12 months was measured using the semi-quantitative food frequency questionnaire, and HRV was obtained through electrocardiographic tracings during 10 min at rest. Independent association between the frequency of coffee consumption "never or almost never", "≤1 cup/day", "2-3 cups/day", "≥3 cups/day", and HRV was estimated using generalized linear regression, adjusting for socio-demographic characteristics, health-related behavior, markers of abnormal metabolism, and the presence of coronary artery disease. Further, we applied Bonferroni correction in the full models. The mean age was 52 years (standard deviation (SD) = 9.1), and 52% was female; 9.5% never/almost never consumed coffee. In univariate analysis, coffee consumers had reduced values of HRV indexes, but after full adjustments and correction for multiple comparisons, these associations disappeared. A trend of reduction in HRV vagal indexes was observed in those that consumed ≥3 cups of coffee/day. Most of the effects attributed to the chronic use of coffee on the HRV indexes is related to the higher prevalence of unhealthy habits in coffee users, such as smoking and alcohol use. Adjustment for confounding factors weaken this association, making it non-significant. The effect of higher daily doses of coffee on the autonomic system should be evaluated in further studies.

Iyengar Yoga Increases Cardiac Parasympathetic Nervous Modulation among Healthy Yoga Practitioners

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Kerstin Khattab

2007-01-01

Full Text Available Relaxation techniques are established in managing of cardiac patients during rehabilitation aiming to reduce future adverse cardiac events. It has been hypothesized that relaxation-training programs may significantly improve cardiac autonomic nervous tone. However, this has not been proven for all available relaxation techniques. We tested this assumption by investigating cardiac vagal modulation during yoga.We examined 11 healthy yoga practitioners (7 women and 4 men, mean age: 43 ± 11; range: 26–58 years. Each individual was subjected to training units of 90 min once a week over five successive weeks. During two sessions, they practiced a yoga program developed for cardiac patients by B.K.S. Iyengar. On three sessions, they practiced a placebo program of relaxation. On each training day they underwent ambulatory 24 h Holter monitoring. The group of yoga practitioners was compared to a matched group of healthy individuals not practicing any relaxation techniques. Parameters of heart rate variability (HRV were determined hourly by a blinded observer. Mean RR interval (interval between two R-waves of the ECG was significantly higher during the time of yoga intervention compared to placebo and to control (P < 0.001 for both. The increase in HRV parameters was significantly higher during yoga exercise than during placebo and control especially for the parameters associated with vagal tone, i.e. mean standard deviation of NN (Normal Beat to Normal Beat of the ECG intervals for all 5-min intervals (SDNNi, P < 0.001 for both and root mean square successive difference (rMSSD, P < 0.01 for both. In conclusion, relaxation by yoga training is associated with a significant increase of cardiac vagal modulation. Since this method is easy to apply with no side effects, it could be a suitable intervention in cardiac rehabilitation programs.

Sympathovagal imbalance contributes to prehypertension status and cardiovascular risks attributed by insulin resistance, inflammation, dyslipidemia and oxidative stress in first degree relatives of type 2 diabetics.

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Gopal Krushna Pal

Full Text Available Though cardiovascular (CV risks are reported in first-degree relatives (FDR of type 2 diabetics, the pathophysiological mechanisms contributing to these risks are not known. We investigated the association of sympathovagal imbalance (SVI with CV risks in these subjects.Body mass index (BMI, basal heart rate (BHR, blood pressure (BP, rate-pressure product (RPP, spectral indices of heart rate variability (HRV, autonomic function tests, insulin resistance (HOMA-IR, lipid profile, inflammatory markers, oxidative stress (OS marker, rennin, thyroid profile and serum electrolytes were measured and analyzed in subjects of study group (FDR of type 2 diabetics, n = 72 and control group (subjects with no family history of diabetes, n = 104.BMI, BP, BHR, HOMA-IR, lipid profile, inflammatory and OS markers, renin, LF-HF (ratio of low-frequency to high-frequency power of HRV, a sensitive marker of SVI were significantly increased (p<0.0001 in study group compared to the control group. SVI in study group was due to concomitant sympathetic activation and vagal inhibition. There was significant correlation and independent contribution of markers of insulin resistance, dyslipidemia, inflammation and OS to LF-HF ratio. Multiple-regression analysis demonstrated an independent contribution of LF-HF ratio to prehypertension status (standardized beta 0.415, p<0.001 and bivariate logistic-regression showed significant prediction (OR 2.40, CI 1.128-5.326, p = 0.002 of LF-HF ratio of HRV to increased RPP, the marker of CV risk, in study group.SVI in FDR of type 2 diabetics occurs due to sympathetic activation and vagal withdrawal. The SVI contributes to prehypertension status and CV risks caused by insulin resistance, dyslipidemia, inflammation and oxidative stress in FDR of type 2 diabetics.

Modulation of vagal tone enhances gastroduodenal motility and reduces somatic pain sensitivity

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Frøkjaer, J B; Bergmann, S; Brock, C

2016-01-01

algometry, conditioned pain modulation using a cold pressor test and a liquid meal ultrasonographic gastroduodenal motility test were performed. KEY RESULTS: Cardiac vagal tone increased during active treatment with t-VNS and DSB compared to sham (p = 0.009). In comparison to sham, thresholds to bone pain...... increased (p = 0.001), frequency of antral contractions increased (p = 0.004) and gastroduodenal motility index increased (p = 0.016) with active treatment. However, no effect on muscle pain thresholds and conditioned pain modulation was seen. CONCLUSIONS & INFERENCES: This experimental study suggests...

High-Resolution Manometry Evaluation of Pressures at the Pharyngo-upper Esophageal Area in Patients with Oropharyngeal Dysphagia Due to Vagal Paralysis.

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Pinna, Bruno Rezende; Herbella, Fernando A M; de Biase, Noemi; Vaiano, Thays C G; Patti, Marco G

2017-10-01

The motility of the pharynx, upper esophageal sphincter (UES), and proximal esophagus in patients with oropharyngeal dysphagia is still not entirely understood. High-resolution manometry (HRM) was recently added to the armamentarium for the study of this area. This study aims to describe HRM findings in patients with vagal paralysis. Sixteen patients (mean age 54 years, 69% females) with oropharyngeal dysphagia due to unilateral vagal paralysis were prospectively studied. All patients underwent HRM. Motility of the UES and at the topography of the velopharynx and epiglottis were recorded. (1) UES relaxation is compromised in a minority of patients, (2) epiglottis pressure does not follow a specific pattern, (3) vellum is hypotonic in half of the patients, (4) dysphagia is related to a low pharyngeal pressure, not to a flow obstruction at the level of the UES, and (5) aspiration is related to low pressures at the level of the UES and epiglottis and higher pressures at the level of the vellum. Pharyngeal motility is significantly impaired in patients with oropharyngeal dysphagia and unilateral vagal paralysis. In half of the cases, UES resting pressure is preserved due to unilateral innervation and relaxation is normal in most patients. Dysphagia therapy in these patients must be directed toward improvement in the oropharyngeal motility not at the UES.

Dynamic changes in parent affect and adolescent cardiac vagal regulation: a real-time analysis.

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Cui, Lixian; Morris, Amanda Sheffield; Harrist, Amanda W; Larzelere, Robert E; Criss, Michael M

2015-04-01

The current study explored the role of parents' negative and positive affect in adolescent respiratory sinus arrhythmia (RSA) reactivity during a parent-adolescent conflict discussion task and the moderating effects of adolescent sex and age. Questionnaire data were collected from 206 adolescents (10-18 years of age; M = 13.37 years) and their primary caregivers (83.3% biological mothers). Electrocardiogram and respiration data were collected from adolescents, and RSA variables were computed. Parent affect was coded during the conflict discussion task. Multilevel modeling was used to distinguish the between- and within-individual effects of parent affect on adolescent RSA. Results indicated that observed within-parent-teen dyad anger was negatively associated with adolescent RSA, controlling for previous-minute RSA level, particularly among adolescents 13 years and older. In addition, observed between-dyad positive affect was positively linked to RSA for both boys and girls when previous-minute RSA level was controlled. Within-dyad positive affect was positively related to girl's RSA only. These findings suggest that expressions of positive affect may be related to better vagal regulation (RSA increases), whereas expressions of anger may be related to poor vagal regulation (RSA decreases) during social engagement. (c) 2015 APA, all rights reserved).

Ventricular tachyarrhythmia-related basal cardiomyopathy in rabbits with vagal stimulation--a novel experimental model for inverted Takotsubo-like cardiomyopathy.

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Takato, Tetsuya; Ashida, Terunao; Seko, Yoshinori; Fujii, Jun; Kawai, Sachio

2010-07-01

Electrical stimulation of the intact (unsectioned) cervical vagus in rabbits frequently provokes ventricular tachyarrhythmias that are often accompanied by mitral regurgitation. Unique pathological lesions often arise on the mitral valve, papillary muscles, and mitral annulus (mitral complex), the latter two of which become swollen and stiffened. These lesions are reversible in nature. Previous studies have essentially ignored the basal portion except for the mitral annulus. Therefore, the present study examined pathological lesions on the left ventricular basal portion in rabbits. The intact right vagal nerves of 20 anesthetized rabbits were repeatedly electrically stimulated under electrocardiographic monitoring. Colloidal carbon (lml) was injected intravenously immediately after the end of the stimulation and all animals were killed 1 week later. Pathological lesions were identified as carbon deposits visible at gross examination. Ventricular bigeminy was induced after vagal stimulation in 15 (75%) of the 20 rabbits. Pathological lesions were evident on the basal portion in 16 (80%) and on the mitral valve and papillary muscles of 15 (75%) of the 20 rabbits. Ventricular bigeminy was closely associated with the development of the pathological lesions, which were rarely observed on the ventricular apex. Cardiomyopathic lesions involving the basal portion and mitral complex were frequently induced in rabbits by vagal stimulation. These lesions bear a close similarity in distribution and reversibility to inverted Takotsubo cardiomyopathy. Copyright 2010 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Relationships between parameters of gallbladder motility and brain electrical activity

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Olena M Marfiyan

2016-08-01

Objective. Earlier we shown that Cholecystokinetic effect of balneotherapy on spa Truskavets’ may be the result of modulation of neuroendocrine-immune complex. The aim of present investigation: clarification relationships between parameters of gallbladder motility and ongoing Electroencephalogram (EEG as well as Heart Rate Variability (HRV. Material and Methods. At 22 men with chronic cholecystite combined with pyelonephrite we recorded twice basal and postprandial volume of gallbladder (Echoscopy by “Radmir”, EEG ("NeuroCom Standard" and HRV ("CardioLab+HRV". Results. Basal gallbladder volume correlated positively with HRV markers of Vagal tone (HF, RMSSD, pNN50 and relative Power Spectrum Density (PSD C4-δ while negatively with Amplitude of β-Rhythm and its absolute PSD in loci P3, P4, Fp1, C3, F3, F4 as well as PSD T3-δ and Frequency of α-Rhythm. Canonical correlation is very strong: R=0,96; Adjusted R2=0,85; χ2(15=61; p<10-5. Gallbladder volume after 5 min after taking of Cholekinetik (50 ml of 40% solution of xylitol, expressed as portion its basal volume, correlated positively with VLF, Deviation of θ-Rhythm and its relative PSD in loci F4, P4 and P3 while negatively with relative PSD O1-θ and absolute PSD P4-β and T6-β as well as Asymmetry of θ-Rhythm. Canonical correlation is very strong too: R=0,87; Adjusted R2=0,66; χ2(9=38; p<10-4. As distinct from early next postprandial volumes significantly less liable to neural regulatory influences: R makes 0,67 (p=0,003 and 0,60 (p=0,009 after 15 and 30 min respectively. In particular, both V15 and V30 equal positively correlated with HF and Laterality of α-Rhythm, however V15 correlated with Asymmetry of θ-Rhythm (r=-0,45 and its PSD in loci F3 (r=0,28 and C4 (r=0,27, while V30 correlated with Asymmetry of δ-Rhythm (r=-0,28 and PSD C4-β (r=-0,34. Conclusion. Fasting gallbladder volume is strong controlled by Vagal nerves as well as by neural structures generating β-Rhythm, whereas early (5

Interacting influences of gender and chronic pain status on parasympathetically mediated heart rate variability in adolescents and young adults.

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Walker, Lynn S; Stone, Amanda L; Smith, Craig A; Bruehl, Stephen; Garber, Judy; Puzanovova, Martina; Diedrich, André

2017-08-01

Considerable research links chronic pain to autonomic nervous system (ANS) dysfunction, specifically low heart rate variability (HRV) mediated by reduced parasympathetic activity. However, little is known about factors that influence ANS function in chronic pain. The ANS is the primary pathway for brain-gut communication, making it of particular interest in gastrointestinal disorders, such as irritable bowel syndrome, characterized by functional abdominal pain (FAP). We evaluated the relation of sex, pain severity, and psychological stress to ANS function in adolescents/young adults from a database of pediatric FAP and control participants enrolled 8 years earlier in a prospective study of pain. At follow-up in adolescence/young adulthood (Mean age = 19.46, SD = 3.48), we classified participants as Pain-Remit (n = 130), Pain-Persist (n = 96), and pain-free controls (n = 123). We recorded electrocardiogram data at rest and during laboratory stressors. Results demonstrated significantly lower HRV in Pain-Persist females compared with Pain-Remit females, female controls, and all males regardless of pain category. Spectral analysis of electrocardiogram showed that Pain-Persist females had reduced power in the high frequency domain of cardiac activity, ie, reduced parasympathetic "braking" of sympathetic activity, both at rest and during stress. Pain-Remit females exhibited levels of autonomic imbalance intermediate between those of females with persistent FAP and all other participants. Parasympathetically mediated low HRV in young women with persistent FAP may reflect a peripheral mechanism (eg, gut dysfunction) or a central nervous system mechanism (eg, pain amplification or poor emotion self-regulation) involving prolonged sympathetic activation.

Foot reflexology can increase vagal modulation, decrease sympathetic modulation, and lower blood pressure in healthy subjects and patients with coronary artery disease.

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Lu, Wan-An; Chen, Gau-Yang; Kuo, Cheng-Deng

2011-01-01

Complementary and alternative medicine (CAM) has long been used by people to postpone the aging process and to reverse disease progression. Reflexology is a CAM method that involves massage to reflex areas in the feet and hands. This study investigated the effect of foot reflexology (FR) on the autonomic nervous modulation in patients with coronary artery disease (CAD) by using heart rate variability analysis. Seventeen people with angiographically patent coronary arteries and 20 patients with CAD scheduled for coronary artery bypass graft surgery were recruited as the control and CAD groups, respectively. The normalized high-frequency power (nHFP) was used as the index of vagal modulation and the normalized very low-frequency power (nVLFP) as the index of vagal withdrawal and renin-angiotensin modulation. In both control and CAD groups, the nHFP was increased significantly whereas the nVLFP was decreased significantly 30 and 60 minutes after FR, as compared with those before FR. The systolic, diastolic, mean arterial, and pulse pressures were significantly decreased after FR in both groups of participants. In the CAD group, the percentage change in heart rate 30 and 60 minutes after FR was smaller than that in the control, and the percentage change in nVLFP 60 minutes after FR was smaller than that in the control. In conclusion, a higher vagal modulation, lower sympathetic modulation, and lower blood pressure can be observed following 60 minutes of FR in both controls and CAD patients. The magnitude of change in the autonomic nervous modulation in CAD patients was slightly smaller than that in the controls. FR may be used as an efficient adjunct to the therapeutic regimen to increase the vagal modulation and decrease blood pressure in both healthy people and CAD patients.

The effect of the number of consecutive night shifts on diurnal rhythms in cortisol, melatonin and heart rate variability (HRV)

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Jensen, Marie Aarrebo; Garde, Anne Helene; Kristiansen, Jesper

2016-01-01

PURPOSE: The purpose of this review is to summarize the current knowledge from field studies on how many consecutive night shifts are required for adaptation of diurnal rhythms in cortisol, melatonin and heart rate variability (HRV) to night work. METHODS: A systematic search of the databases Pub...... recordings for HRV. Most of the studies in the review were small studies with less than 30 participants, and most studies evaluated diurnal rhythms after only two consecutive night shifts whereas only six studies used seven or more consecutive night shifts. The majority of studies found that adaptation...... to night work had not occurred after two consecutive night shifts, whereas a small number found evidence for full adaptation after seven consecutive night shifts based on diurnal rhythms in cortisol and melatonin. CONCLUSION: There are methodological differences in the field studies analyzing diurnal...

Human autonomic rhythms: vagal cardiac mechanisms in tetraplegic subjects

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Koh, J.; Brown, T. E.; Beightol, L. A.; Ha, C. Y.; Eckberg, D. L.

1994-01-01

1. We studied eight young men (age range: 20-37 years) with chronic, clinically complete high cervical spinal cord injuries and ten age-matched healthy men to determine how interruption of connections between the central nervous system and spinal sympathetic motoneurones affects autonomic cardiovascular control. 2. Baseline diastolic pressures and R-R intervals (heart periods) were similar in the two groups. Slopes of R-R interval responses to brief neck pressure changes were significantly lower in tetraplegic than in healthy subjects, but slopes of R-R interval responses to steady-state arterial pressure reductions and increases were comparable. Plasma noradrenaline levels did not change significantly during steady-state arterial pressure reductions in tetraplegic patients, but rose sharply in healthy subjects. The range of arterial pressure and R-R interval responses to vasoactive drugs (nitroprusside and phenylephrine) was significantly greater in tetraplegic than healthy subjects. 3. Resting R-R interval spectral power at respiratory and low frequencies was similar in the two groups. During infusions of vasoactive drugs, low-frequency R-R interval spectral power was directly proportional to arterial pressure in tetraplegic patients, but was unrelated to arterial pressure in healthy subjects. Vagolytic doses of atropine nearly abolished both low- and respiratory-frequency R-R interval spectral power in both groups. 4. Our conclusions are as follows. First, since tetraplegic patients have significant levels of low-frequency arterial pressure and R-R interval spectral power, human Mayer arterial pressure waves may result from mechanisms that do not involve stimulation of spinal sympathetic motoneurones by brainstem neurones. Second, since in tetraplegic patients, low-frequency R-R interval spectral power is proportional to arterial pressure, it is likely to be mediated by a baroreflex mechanism. Third, since low-frequency R-R interval rhythms were nearly abolished

Acute physiological and electrical accentuation of vagal tone has no effect on pain or gastrointestinal motility in chronic pancreatitis

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Juel, Jacob; Brock, Christina; Olesen, Soren S.

2017-01-01

derived parameters of autonomic tone, quantitative sensory testing of bone and muscle pain pressure, conditioned pain modulation (CPM) and assessments of gastroduodenal motility with ultrasound were performed. Results: In comparison to sham, t-VNS and DSB increased cardiac vagal tone (CVT) (P

Interactions Between Epinephrine, Ascending Vagal Fibers and Central Noradrenergic Systems in Modulating Memory for Emotionally Arousing Events.

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Cedric L. Williams

2012-06-01

Full Text Available It is well established that exposure to emotionally laden events initiates secretion of the arousal related hormone epinephrine in the periphery. These neuroendocrine changes and the subsequent increase in peripheral physiological output play an integral role in modulating brain systems involved in memory formation. The impermeability of the blood brain barrier to epinephrine represents an important obstacle in understanding how peripheral hormones initiate neurochemical changes in the brain that lead to effective memory formation. This obstacle necessitated the identity of a putative pathway capable of conveying physiological changes produced by epinephrine to limbic structures that incorporate arousal and affect related information into memory. A major theme of the proposed studies is that ascending fibers of the vagus nerve may represent such a mechanism. This hypothesis was tested by evaluating the contribution of ascending vagal fibers in modulating memory for responses learned under behavioral conditions that produce emotional arousal by manipulating appetitive stimuli. A combination of electrophysiological recording of vagal afferent fibers and in vivo microdialysis was employed in a second study to simultaneously assess how elevations in peripheral levels of epinephrine affect vagal nerve discharge and the subsequent potentiation of norepinephrine release in the basolateral amygdala. The final study used double immunohistochemistry labeling of c-fos and dopamine beta hydroxylase, the enzyme for norepinephrine synthesis to determine if epinephrine administration alone or stimulation of the vagus nerve at an intensity identical to that which improved memory in Experiment 1 produces similar patterns of neuronal activity in brain areas involved in processing memory for emotional events. Findings emerging from this collection of studies establish the importance of ascending fibers of the vagus nerve as an essential pathway for conveying the

GLP-1 receptor stimulation depresses heart rate variability and inhibits neurotransmission to cardiac vagal neurons.

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Griffioen, Kathleen J; Wan, Ruiqian; Okun, Eitan; Wang, Xin; Lovett-Barr, Mary Rachael; Li, Yazhou; Mughal, Mohamed R; Mendelowitz, David; Mattson, Mark P

2011-01-01

glucagon-like peptide 1 (GLP-1) is an incretin hormone released from the gut in response to food intake. Whereas GLP-1 acts in the periphery to inhibit glucagon secretion and stimulate insulin release, it also acts in the central nervous system to mediate autonomic control of feeding, body temperature, and cardiovascular function. Because of its role as an incretin hormone, GLP-1 receptor analogs are used as a treatment for type 2 diabetes. Central or peripheral administration of GLP-1 increases blood pressure and heart rate, possibly by activating brainstem autonomic nuclei and increasing vagus nerve activity. However, the mechanism(s) by which GLP-1 receptor stimulation affects cardiovascular function are unknown. We used the long-lasting GLP-1 receptor agonist Exendin-4 (Ex-4) to test the hypothesis that GLP-1 signalling modulates central parasympathetic control of heart rate. using a telemetry system, we assessed heart rate in mice during central Ex-4 administration. Heart rate was increased by both acute and chronic central Ex-4 administration. Spectral analysis indicated that the high frequency and low frequency powers of heart rate variability were diminished by Ex-4 treatment. Finally, Ex-4 decreased both excitatory glutamatergic and inhibitory glycinergic neurotransmission to preganglionic parasympathetic cardiac vagal neurons. these data suggest that central GLP-1 receptor stimulation diminishes parasympathetic modulation of the heart thereby increasing heart rate.

Correlation between cardiac autonomic modulation in response to orthostatic stress and indicators of quality of life, physical capacity, and physical activity in healthy individuals.

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Gonçalves, Thiago R; Farinatti, Paulo de Tarso Veras; Gurgel, Jonas L; da Silva Soares, Pedro P

2015-05-01

Increased heart rate variability (HRV) at rest is frequently associated to maximal oxygen uptake (VO2max), physical activity, and markers of quality of life (QoL). However, the HRV has not been observed during physical exercise or orthostatic (ORT) challenge. This study investigated the associations of HRV changes (ΔHRV) from rest at supine (SUP) to ORT positions with (VO2max), physical activity level, and QoL in young adults. Cardiac autonomic modulation was assessed by spectral analysis of R-R time series measured from SUP to ORT positions in 15 healthy volunteers (26 ± 7 years). Questionnaires were applied for evaluation of QoL (SF-36 score), to estimate (VO2max), and to quantify physical activity (Baecke Sport Score). All HRV indices at SUP, but not ORT, strongly correlated to QoL, estimated (VO2max), and physical activity. The ΔHRV from SUP to ORT showed significant correlations with all questionnaire scores (r = 0.52-0.61 for low frequency and r = -0.61 to -0.65 for high frequency, p ≤ 0.05). Higher vagal activity at rest and greater changes in adrenergic and parasympathetic modulation from SUP to ORT were detected in the volunteers exhibiting higher scores of QoL, estimated (VO2max), and physical activity. Taken together, the level of neural adaptations from resting SUP position to active standing, and physical activity and QoL questionnaires seem to be a simple approach to understand the physiological and lifestyle adaptations to exercise that may be applied to a large sample of subjects in almost any sports facilities at a low cost.

Coffee Consumption and Heart Rate Variability: The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil Cohort Study

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Rackel Aguiar Mendes de Oliveira

2017-07-01

Full Text Available Studies have shown that acute coffee ingestion can affect cardiovascular autonomic activity, although the chronic effects on heart rate variability (HRV remain controversial. Method: A cross-sectional study with baseline data (2008–2010 from ELSA-Brasil cohort of 15,105 (aged 35–74, based in six Brazilian states. Coffee consumption in the previous 12 months was measured using the semi-quantitative food frequency questionnaire, and HRV was obtained through electrocardiographic tracings during 10 min at rest. Independent association between the frequency of coffee consumption “never or almost never”, “≤1 cup/day”, “2–3 cups/day”, “≥3 cups/day”, and HRV was estimated using generalized linear regression, adjusting for socio-demographic characteristics, health-related behavior, markers of abnormal metabolism, and the presence of coronary artery disease. Further, we applied Bonferroni correction in the full models. Results: The mean age was 52 years (standard deviation (SD = 9.1, and 52% was female; 9.5% never/almost never consumed coffee. In univariate analysis, coffee consumers had reduced values of HRV indexes, but after full adjustments and correction for multiple comparisons, these associations disappeared. A trend of reduction in HRV vagal indexes was observed in those that consumed ≥3 cups of coffee/day. Conclusion: Most of the effects attributed to the chronic use of coffee on the HRV indexes is related to the higher prevalence of unhealthy habits in coffee users, such as smoking and alcohol use. Adjustment for confounding factors weaken this association, making it non-significant. The effect of higher daily doses of coffee on the autonomic system should be evaluated in further studies.

A method for continuously assessing the autonomic response to music-induced emotions through HRV analysis.

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Orini, Michele; Bailón, Raquel; Enk, Ronny; Koelsch, Stefan; Mainardi, Luca; Laguna, Pablo

2010-05-01

Interest in therapeutic applications of music has recently increased, as well as the effort to understand the relationship between music features and physiological patterns. In this study, we present a methodology for characterizing music-induced effects on the dynamics of the heart rate modulation. It consists of three steps: (i) the smoothed pseudo Wigner-Ville distribution is performed to obtain a time-frequency representation of HRV; (ii) a parametric decomposition is used to robustly estimate the time-course of spectral parameters; and (iii) statistical population analysis is used to continuously assess whether different acoustic stimuli provoke different dynamic responses. Seventy-five healthy subjects were repetitively exposed to pleasant music, sequences of Shepard tones with the same tempo as the pleasant music and unpleasant sounds overlaid with the same sequences of Shepard tones. Results show that the modification of HRV parameters are characterized by an early fast transient phase (15-20 s), followed by an almost stationary period. All kinds of stimuli provoked significant changes compared to the resting condition, while during listening to pleasant music the heart and respiratory rates were higher (for more than 80% of the duration of the stimuli, p < 10(-5)) and the power of the HF modulation was lower (for more than 70% of the duration of the stimuli, p < 0.05) than during listening to unpleasant stimuli.

Complexity and time asymmetry of heart rate variability are altered in acute mental stress.

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Visnovcova, Z; Mestanik, M; Javorka, M; Mokra, D; Gala, M; Jurko, A; Calkovska, A; Tonhajzerova, I

2014-07-01

We aimed to study the complexity and time asymmetry of short-term heart rate variability (HRV) as an index of complex neurocardiac control in response to stress using symbolic dynamics and time irreversibility methods. ECG was recorded at rest and during and after two stressors (Stroop, arithmetic test) in 70 healthy students. Symbolic dynamics parameters (NUPI, NCI, 0V%, 1V%, 2LV%, 2UV%), and time irreversibility indices (P%, G%, E) were evaluated. Additionally, HRV magnitude was quantified by linear parameters: spectral powers in low (LF) and high frequency (HF) bands. Our results showed a reduction of HRV complexity in stress (lower NUPI with both stressors, lower NCI with Stroop). Pattern classification analysis revealed significantly higher 0V% and lower 2LV% with both stressors, indicating a shift in sympathovagal balance, and significantly higher 1V% and lower 2UV% with Stroop. An unexpected result was found in time irreversibility: significantly lower G% and E with both stressors, P% index significantly declined only with arithmetic test. Linear HRV analysis confirmed vagal withdrawal (lower HF) with both stressors; LF significantly increased with Stroop and decreased with arithmetic test. Correlation analysis revealed no significant associations between symbolic dynamics and time irreversibility. Concluding, symbolic dynamics and time irreversibility could provide independent information related to alterations of neurocardiac control integrity in stress-related disease.

Complexity and time asymmetry of heart rate variability are altered in acute mental stress

International Nuclear Information System (INIS)

Visnovcova, Z; Mestanik, M; Javorka, M; Mokra, D; Calkovska, A; Tonhajzerova, I; Gala, M; Jurko, A

2014-01-01

We aimed to study the complexity and time asymmetry of short-term heart rate variability (HRV) as an index of complex neurocardiac control in response to stress using symbolic dynamics and time irreversibility methods. ECG was recorded at rest and during and after two stressors (Stroop, arithmetic test) in 70 healthy students. Symbolic dynamics parameters (NUPI, NCI, 0V%, 1V%, 2LV%, 2UV%), and time irreversibility indices (P%, G%, E) were evaluated. Additionally, HRV magnitude was quantified by linear parameters: spectral powers in low (LF) and high frequency (HF) bands. Our results showed a reduction of HRV complexity in stress (lower NUPI with both stressors, lower NCI with Stroop). Pattern classification analysis revealed significantly higher 0V% and lower 2LV% with both stressors, indicating a shift in sympathovagal balance, and significantly higher 1V% and lower 2UV% with Stroop. An unexpected result was found in time irreversibility: significantly lower G% and E with both stressors, P% index significantly declined only with arithmetic test. Linear HRV analysis confirmed vagal withdrawal (lower HF) with both stressors; LF significantly increased with Stroop and decreased with arithmetic test. Correlation analysis revealed no significant associations between symbolic dynamics and time irreversibility. Concluding, symbolic dynamics and time irreversibility could provide independent information related to alterations of neurocardiac control integrity in stress-related disease. (paper)

Autonomic Modulation in Duchenne Muscular Dystrophy during a Computer Task: A Prospective Control Trial.

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Mayra Priscila Boscolo Alvarez

Full Text Available Duchenne Muscular Dystrophy (DMD is characterized by progressive muscle weakness that can lead to disability. Owing to functional difficulties faced by individuals with DMD, the use of assistive technology is essential to provide or facilitate functional abilities. In DMD, cardiac autonomic dysfunction has been reported in addition to musculoskeletal impairment. Consequently, the objective was to investigate acute cardiac autonomic responses, by Heart Rate Variability (HRV, during computer tasks in subjects with DMD.HRV was assessed by linear and nonlinear methods, using the heart rate monitor Polar RS800CX chest strap Electrocardiographic measuring device. Then, 45 subjects were included in the group with DMD and 45 in the healthy Typical Development (TD control group. They were assessed for twenty minutes at rest sitting, and five minutes after undergoing a task on the computer.Individuals with DMD had a statistically significant lower parasympathetic cardiac modulation at rest when compared to the control group, which further declined when undergoing the tasks on the computer.DMD patients presented decreased HRV and exhibited greater intensity of cardiac autonomic responses during computer tasks characterized by vagal withdrawal when compared to the healthy TD control subjects.

A pilot randomized study of a gratitude journaling intervention on HRV and inflammatory biomarkers in Stage B heart failure patients

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Redwine, Laura; Henry, Brook L.; Pung, Meredith A.; Wilson, Kathleen; Chinh, Kelly; Knight, Brian; Jain, Shamini; Rutledge, Thomas; Greenberg, Barry; Maisel, Alan; Mills, Paul J

2016-01-01

Objective Stage B, asymptomatic heart failure (HF) presents a therapeutic window for attenuating disease progression and development of HF symptoms, and improving quality of life. Gratitude, the practice of appreciating positive life features, is highly related to quality of life, leading to development of promising clinical interventions. However, few gratitude studies have investigated objective measures of physical health; most relied on self-report measures. We conducted a pilot study in Stage B HF patients to examine whether gratitude journaling improved biomarkers related to HF prognosis. Methods Patients (N = 70; mean age = 66.2 years, SD = 7.6) were randomized to an 8-week gratitude journaling intervention or treatment as usual (TAU). Baseline (T1) assessments included 6-item Gratitude Questionnaire (GQ-6), resting heart rate variability (HRV), and an inflammatory biomarker index. At T2 (mid-intervention) GQ6 was measured. At T3 (post-intervention), T1 measures were repeated but also included a gratitude journaling task. Results The gratitude intervention was associated with improved trait gratitude scores (F = 6.0, p = .017, η2 = .10), reduced inflammatory biomarker index score over time (F = 9.7, p = .004, η2 = .21) and increased parasympathetic HRV responses during the gratitude journaling task (F = 4.2, p = .036, η2 = .15), compared with TAU. However, there were no resting pre- to post-intervention group differences in HRV (p's > .10). Conclusions Gratitude journaling may improve biomarkers related to HF morbidity, such as reduced inflammation; large-scale studies with active control conditions are needed to confirm these findings. PMID:27187845

Evaluation of the influence of ayurvedic formulation (Ayushman-15) on psychopathology, heart rate variability and stress hormonal level in major depression (Vishada).

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Kishore, Ramakrishna K; Abhishekh, Hulegar A; Udupa, Kaviraja; Thirthalli, Jagadisha; Lavekar, Gandhidas S; Gangadhar, Bangalore N; Raju, Trichur R; Sathyaprabha, Talakad N

2014-12-01

Ayurveda (Indian-complimentary and alternative medicine) is still most sought after in India and has promising potential in management of Vishada [major depressive disorder (MDD)]. But, systematic research is lacking. In this study we evaluated of influence of ayurvedic treatment (Panchakarma and Ayushman-15) on psychopathology, heart rate variability (HRV) and endocrinal parameters in patients with major depression. 81 drug naive patients diagnosed as Vishada by ayurvedic physician and MDD according to DSM IV-TR were given ayurvedic Virechana module (therapeutic purgation) and were randomized into two groups. Patients in group A (n=41) received Ayushman-15A while group B (n=40) received Ayushman-15B for two months and Shirodhara (forehead-oil pouring therapy). Patients were assessed with Hamilton Depression Rating Scale (HDRS), Montgomery Asberg Depression Rating Scale (MADRS), Heart Rate Variability (HRV). Cortisol and adrenocorticotropic hormone (ACTH) were estimated at baseline and after ayurvedic therapy. HRV and endocrinal parameters were compared with age and gender matched healthy volunteers. HRV parameters showed significant sympathetic dominance in patients compared to healthy volunteers. Two months of ayurvedic treatment significantly decreased psychopathology, showed increase in vagal tone, decrease in sympathetic tone and reduced cortisol levels. However, there was no significant difference between groups receiving Ayushman A and B. This study provides evidence for antidepressant, cardiac (HRV) and beneficial neuroendocrine modulatory influence of Ayurveda therapy in patients of Vishada (MDD). Further studies are needed to confirm these findings. Greater insight into the neurobiology behind this therapy might provide valuable information about newer drug target. Copyright © 2014 Elsevier B.V. All rights reserved.

Modulation of Neurally Mediated Vasodepression and Bradycardia by Electroacupuncture through Opioids in Nucleus Tractus Solitarius.

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Tjen-A-Looi, Stephanie C; Fu, Liang-Wu; Guo, Zhi-Ling; Longhurst, John C

2018-01-30

Stimulation of vagal afferent endings with intravenous phenylbiguanide (PBG) causes both bradycardia and vasodepression, simulating neurally mediated syncope. Activation of µ-opioid receptors in the nucleus tractus solitarius (NTS) increases blood pressure. Electroacupuncture (EA) stimulation of somatosensory nerves underneath acupoints P5-6, ST36-37, LI6-7 or G37-39 selectively but differentially modulates sympathoexcitatory responses. We therefore hypothesized that EA-stimulation at P5-6 or ST36-37, but not LI6-7 or G37-39 acupoints, inhibits the bradycardia and vasodepression through a µ-opioid receptor mechanism in the NTS. We observed that stimulation at acupoints P5-6 and ST36-37 overlying the deep somatosensory nerves and LI6-7 and G37-39 overlying cutaneous nerves differentially evoked NTS neural activity in anesthetized and ventilated animals. Thirty-min of EA-stimulation at P5-6 or ST36-37 reduced the depressor and bradycardia responses to PBG while EA at LI6-7 or G37-39 did not. Congruent with the hemodynamic responses, EA at P5-6 and ST36-37, but not at LI6-7 and G37-39, reduced vagally evoked activity of cardiovascular NTS cells. Finally, opioid receptor blockade in the NTS with naloxone or a specific μ-receptor antagonist reversed P5-6 EA-inhibition of the depressor, bradycardia and vagally evoked NTS activity. These data suggest that point specific EA stimulation inhibits PBG-induced vasodepression and bradycardia responses through a μ-opioid mechanism in the NTS.

Loss of vagal tone aggravates systemic inflammation and cardiac impairment in endotoxemic rats.

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Schulte, Astrid; Lichtenstern, Christoph; Henrich, Michael; Weigand, Markus A; Uhle, Florian

2014-05-15

During the course of sepsis, often myocardial depression with hemodynamic impairment occurs. Acetylcholine, the main transmitter of the parasympathetic Nervus vagus, has been shown to be of importance for the transmission of signals within the immune system and also for a variety of other functions throughout the organism. Hypothesizing a potential correlation between this dysfunction and hemodynamic impairment, we wanted to assess the impact of vagal stimulation on myocardial inflammation and function in a rat model of lipopolysaccharide (LPS)-induced septic shock. As the myocardial tissue is (sparsely) innervated by the N. vagus, there might be an important anti-inflammatory effect in the heart, inhibiting proinflammatory gene expression in cardiomyocytes and improving cardiac function. We performed stimulation of the right cervical branch of the N. vagus in vagotomized, endotoxemic (1 mg/kg body weight LPS, intravenously) rats. Hemodynamic parameters were assessed over time using a left ventricular pressure-volume catheter. After the experiments, hearts and blood plasma were collected, and the expression of proinflammatory cytokines was measured using quantitative reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. After vagotomy, the inflammatory response was aggravated, measurable by elevated cytokine levels in plasma and ventricular tissue. In concordance, cardiac impairment during septic shock was pronounced in these animals. To reverse both hemodynamic and immunologic effects of diminished vagal tone, even a brief stimulation of the N. vagus was enough during initial LPS infusion. Overall, the N. vagus might play a major role in maintaining hemodynamic stability and cardiac immune homeostasis during septic shock. Copyright © 2014 Elsevier Inc. All rights reserved.

Psychoactive bacteria Lactobacillus rhamnosus (JB-1) elicits rapid frequency facilitation in vagal afferents.

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Perez-Burgos, Azucena; Wang, Bingxian; Mao, Yu-Kang; Mistry, Bhavik; McVey Neufeld, Karen-Anne; Bienenstock, John; Kunze, Wolfgang

2013-01-15

Mounting evidence supports the influence of the gut microbiome on the local enteric nervous system and its effects on brain chemistry and relevant behavior. Vagal afferents are involved in some of these effects. We previously showed that ingestion of the probiotic bacterium Lactobacillus rhamnosus (JB-1) caused extensive neurochemical changes in the brain and behavior that were abrogated by prior vagotomy. Because information can be transmitted to the brain via primary afferents encoded as neuronal spike trains, our goal was to record those induced by JB-1 in vagal afferents in the mesenteric nerve bundle and thus determine the nature of the signals sent to the brain. Male Swiss Webster mice jejunal segments were cannulated ex vivo, and serosal and luminal compartments were perfused separately. Bacteria were added intraluminally. We found no evidence for translocation of labeled bacteria across the epithelium during the experiment. We recorded extracellular multi- and single-unit neuronal activity with glass suction pipettes. Within minutes of application, JB-1 increased the constitutive single- and multiunit firing rate of the mesenteric nerve bundle, but Lactobacillus salivarius (a negative control) or media alone were ineffective. JB-1 significantly augmented multiunit discharge responses to an intraluminal distension pressure of 31 hPa. Prior subdiaphragmatic vagotomy abolished all of the JB-1-evoked effects. This detailed exploration of the neuronal spike firing that encodes behavioral signaling to the brain may be useful to identify effective psychoactive bacteria and thereby offer an alternative new perspective in the field of psychiatry and comorbid conditions.

Hypocretin-1 (orexin A) prevents the effects of hypoxia/hypercapnia and enhances the GABAergic pathway from the lateral paragigantocellular nucleus to cardiac vagal neurons in the nucleus ambiguus.

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Dergacheva, O; Philbin, K; Bateman, R; Mendelowitz, D

2011-02-23

Hypocretins (orexins) are hypothalamic neuropeptides that play a crucial role in regulating sleep/wake states and autonomic functions including parasympathetic cardiac activity. We have recently demonstrated stimulation of the lateral paragigantocellular nucleus (LPGi), the nucleus which is thought to play a role in rapid eye movement (REM) sleep control, activates an inhibitory pathway to preganglionic cardiac vagal neurons in the nucleus ambiguus (NA). In this study we test the hypothesis that hypocretin-1 modulates the inhibitory neurotransmission to cardiac vagal neurons evoked by stimulation of the LPGi using whole-cell patch-clamp recordings in an in vitro brain slice preparation from rats. Activation of hypocretin-1 receptors produced a dose-dependent and long-term facilitation of GABAergic postsynaptic currents evoked by electrical stimulation of the LPGi. Hypoxia/hypercapnia diminished LPGi-evoked GABAergic current in cardiac vagal neurons and this inhibition by hypoxia/hypercapnia was prevented by pre-application of hypocretin-1. The action of hypocretin-1 was blocked by the hypocretin-1 receptor antagonist SB-334867. Facilitation of LPGi-evoked GABAergic current in cardiac vagal neurons under both normal condition and during hypoxia/hypercapnia could be the mechanism by which hypocretin-1 affects parasympathetic cardiac function and heart rate during REM sleep. Furthermore, our findings indicate a new potential mechanism that might be involved in the cardiac arrhythmias, bradycardia, and sudden cardiac death that can occur during sleep. Copyright © 2011. Published by Elsevier Ltd.

Perturbed sympatho-vagal balance in Turner syndrome - relation to aortic dilation

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Trolle, Christian; Mortensen, Kristian Havmand; Andersen, Niels Holmark

Objective: The risk of aortic dissection is 100 fold increased in Turner syndrome (TS). Increased blood pressure (BP) and heart rate is present as well as an increased risk of ischemic heart disease and diabetes. This study aimed to prospectively assess heart rate variability (HRV) in TS and its...... relation to aortic dimensions. Methods: Adults with TS (n=91, aged 37.4±10.4 years) recruited through the Danish National Society of Turner Syndrome Contact Group and an endocrine outpatient clinic were examined thrice (mean follow-up of 4.7±0.5 years). Healthy controls (n=64, aged 39.4±12.1 years) were...

The vagal innervation of the gut and immune homeostasis.

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Matteoli, Gianluca; Boeckxstaens, Guy E

2013-08-01

The central nervous system interacts dynamically with the immune system to modulate inflammation through humoral and neural pathways. Recently, in animal models of sepsis, the vagus nerve (VN) has been proposed to play a crucial role in the regulation of the immune response, also referred to as the cholinergic anti-inflammatory pathway. The VN, through release of acetylcholine, dampens immune cell activation by interacting with α-7 nicotinic acetylcholine receptors. Recent evidence suggests that the vagal innervation of the gastrointestinal tract also plays a major role controlling intestinal immune activation. Indeed, VN electrical stimulation potently reduces intestinal inflammation restoring intestinal homeostasis, whereas vagotomy has the reverse effect. In this review, we will discuss the current understanding concerning the mechanisms and effects involved in the cholinergic anti-inflammatory pathway in the gastrointestinal tract. Deeper investigation on this counter-regulatory neuroimmune mechanism will provide new insights in the cross-talk between the nervous and immune system leading to the identification of new therapeutic targets to treat intestinal immune disease.

Day-night variation in heart rate variability changes induced by endotoxaemia in healthy volunteers.

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Alamili, M; Rosenberg, J; Gögenur, I

2015-04-01

Morbidity and mortality in response to sepsis may be dependent on clock time for the initiation of sepsis. Endotoxaemia, an experimental model for systemic inflammation, induces alterations in sympatico-vagal balance in the autonomic nervous system (ANS). The activity of sympathetic and parasympathetic activity can be estimated by measuring heart rate variability (HRV). Based on the intimate link between ANS and the inflammatory response, we hypothesized, that HRV changes seen during endotoxaemia would be different based on time of the day the endotoxaemia is initiated. We investigated day/night variation in endotoxaemia-induced changes in HRV. A randomized, crossover study with 12 healthy men (age 18-31) was conducted. Endotoxaemia were induced by lipopolysaccharide (LPS) endotoxin 0.3 ng/kg b.w. in two visits (day visit and night visit). At the day visit, endotoxaemia were induced at 12:00 h, and at the night visit it was induced at 24:00 h. Holter recordings were started 1 h before administration of LPS, and continued for 10 h. Time-domain and frequency-domain parameters of HRV were analysed. A total of nine persons finished the study with valid recordings. Endotoxaemia at both night and day resulted in a significant depression in HRV parameters high-frequency power (HF), low-frequency power (LF), standard deviation of normal-to-normal (NN) intervals, root mean square of successive differences and proportion of NN50 divided by total number of NNs (Pnight-time endotoxaemia, a more pronounced depression of LF, HF and SDNN (Pday-time endotoxaemia. Endotoxaemia induced changes in HRV exhibit a day-night difference. This difference may have clinical consequences in patients with sepsis. © 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Infant diet, gender and the normative development of vagal tone and heart period during the first two years of life

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Relationships between early postnatal diet and the development of cardiac regulation were studied using resting vagal tone and heart period measures obtained quarterly during infancy and at 2 years in 158 breast-fed, 159 milk formula-fed, and 148 soy formula-fed infants. Both measures increased acro...

Is pancreatic polypeptide response to food ingestion a reliable index of vagal function in type 1 diabetes?

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Damholt, M B; Arlien-Soeborg, P; Hilsted, L

2006-01-01

The diagnosis of autonomic neuropathy in diabetic patients is based on cardiovascular reflex tests. Since cardiac function may be affected by arteriosclerosis and cardiomyopathy in type 1 diabetes mellitus, alternative tests reflecting vagal nerve function, in other organ systems, are needed....... In this study the pancreatic polypeptide (PP) response to a mixed meal was evaluated in healthy subjects and in recently diagnosed type 1 diabetic patients....

Linear and non-linear interdependence of EEG and HRV frequency bands in human sleep.

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Chaparro-Vargas, Ramiro; Dissanayaka, P Chamila; Patti, Chanakya Reddy; Schilling, Claudia; Schredl, Michael; Cvetkovic, Dean

2014-01-01

The characterisation of functional interdependencies of the autonomic nervous system (ANS) stands an evergrowing interest to unveil electroencephalographic (EEG) and Heart Rate Variability (HRV) interactions. This paper presents a biosignal processing approach as a supportive computational resource in the estimation of sleep dynamics. The application of linear, non-linear methods and statistical tests upon 10 overnight polysomnographic (PSG) recordings, allowed the computation of wavelet coherence and phase locking values, in order to identify discerning features amongst the clinical healthy subjects. Our findings showed that neuronal oscillations θ, α and σ interact with cardiac power bands at mid-to-high rank of coherence and phase locking, particularly during NREM sleep stages.

KATP channels in the nodose ganglia mediate the orexigenic actions of ghrelin

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Grabauskas, Gintautas; Wu, Xiaoyin; Lu, Yuanxu; Heldsinger, Andrea; Song, Il; Zhou, Shi-Yi; Owyang, Chung

2015-01-01

Abstract Ghrelin is the only known hunger signal derived from the peripheral tissues. Ghrelin overcomes the satiety signals evoked by anorexigenic molecules, such as cholecystokinin (CCK) and leptin, to stimulate feeding. The mechanisms by which ghrelin reduces the sensory signals evoked by anorexigenic hormones, which act via the vagus nerve to stimulate feeding, are unknown. Patch clamp recordings of isolated rat vagal neurons show that ghrelin hyperpolarizes neurons by activating K+ conductance. Administering a KATP channel antagonist or silencing Kir6.2, a major subunit of the KATP channel, abolished ghrelin inhibition in vitro and in vivo. Patch clamp studies show that ghrelin inhibits currents evoked by leptin and CCK-8, which operate through independent ionic channels. The inhibitory actions of ghrelin were abolished by treating the vagal ganglia neurons with pertussis toxin, as well as phosphatidylinositol 3-kinase (PI3K) or extracellular signal-regulated kinase 1 and 2 (Erk1/2) small interfering RNA. In vivo gene silencing of PI3K and Erk1/2 in the nodose ganglia prevented ghrelin inhibition of leptin- or CCK-8-evoked vagal firing. Feeding experiments showed that silencing Kir6.2 in the vagal ganglia abolished the orexigenic actions of ghrelin. These data indicate that ghrelin modulates vagal ganglia neuron excitability by activating KATP conductance via the growth hormone secretagogue receptor subtype 1a–Gαi–PI3K–Erk1/2–KATP pathway. The resulting hyperpolarization renders the neurons less responsive to signals evoked by anorexigenic hormones. This provides a mechanism to explain the actions of ghrelin with respect to overcoming anorexigenic signals that act via the vagal afferent pathways. Key points Ghrelin, a hunger signalling peptide derived from the peripheral tissues, overcomes the satiety signals evoked by anorexigenic molecules, such as cholecystokinin (CCK) and leptin, to stimulate feeding. Using in vivo and in vitro electrophysiological

8-OH-DPAT abolishes the pulmonary C-fiber-mediated apneic response to fentanyl largely via acting on 5HT1A receptors in the nucleus tractus solitarius

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Zhuang, Jianguo; Zhang, Zhenxiong; Zhang, Cancan

2012-01-01

Intravenous bolus injection of morphine causes a vagal-mediated brief apnea (∼3 s), while continuous injection, via action upon central μ-opioid receptor (MOR), arrests ventilation (>20 s) that is eliminated by stimulating central 5-hydroxytryptamine 1A receptors (5HT1ARs). Bronchopulmonary C-fibers (PCFs) are essential for triggering a brief apnea, and their afferents terminate at the caudomedial region of the nucleus tractus solitarius (mNTS) that densely expresses 5HT1ARs. Thus we asked whether the vagal-mediated apneic response to MOR agonists was PCF dependent, and if so, whether this apnea was abolished by systemic administration of 8-hydroxy-2-(di-n-propylamino)tetral (8-OH-DPAT) largely through action upon mNTS 5HT1ARs. Right atrial bolus injection of fentanyl (5.0 μg/kg, a MOR agonist) was performed in the anesthetized and spontaneously breathing rats before and after: 1) selective blockade of PCFs' conduction and subsequent bivagotomy; 2) intravenous administration of 5HT1AR agonist 8-OH-DPAT; 3) intra-mNTS injection of 8-OH-DPAT; and 4) intra-mNTS injection of 5HT1AR antagonist WAY-100635 followed by 8-OH-DPAT (iv). We found the following: First, fentanyl evoked an immediate apnea (2.5 ± 0.4 s, ∼6-fold longer than the baseline expiratory duration, TE), which was abolished by either blocking PCFs' conduction or bivagotomy. Second, this apnea was prevented by systemic 8-OH-DPAT challenge. Third, intra-mNTS injection of 8-OH-DPAT greatly attenuated the apnea by 64%. Finally, intra-mNTS microinjection of WAY-100635 significantly attenuated (58%) the apneic blockade by 8-OH-DPAT (iv). We conclude that the vagal-mediated apneic response to MOR activation depends on PCFs, which is fully antagonized by systemic 8-OH-DPAT challenge largely via acting on mNTS 5HT1ARs. PMID:22696579

Unprovoked atrial tachyarrhythmias in aging spontaneously hypertensive rats: the role of the autonomic nervous system.

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Scridon, Alina; Gallet, Clément; Arisha, Moussa M; Oréa, Valérie; Chapuis, Bruno; Li, Na; Tabib, Alain; Christé, Georges; Barrès, Christian; Julien, Claude; Chevalier, Philippe

2012-08-01

Experimental models of unprovoked atrial tachyarrhythmias (AT) in conscious, ambulatory animals are lacking. We hypothesized that the aging, spontaneously hypertensive rat (SHR) may provide such a model. Baseline ECG recordings were acquired with radiotelemetry in eight young (14-wk-old) and eight aging (55-wk-old) SHRs and in two groups of four age-matched Wistar-Kyoto (WKY) rats. Quantification of AT and heart rate variability (HRV) analysis were performed based on 24-h ECG recordings in unrestrained rats. All animals were submitted to an emotional stress protocol (air-jet). In SHRs, carbamylcholine injections were also performed. Spontaneous AT episodes were observed in all eight aging SHRs (median, 91.5; range, 4-444 episodes/24 h), but not in young SHRs or WKY rats. HRV analysis demonstrated significantly decreased low frequency components in aging SHRs compared with age-matched WKY rats (P aging (P = 0.01) SHRs compared with normotensive controls. In aging SHRs, emotional stress significantly reduced the number of arrhythmic events, whereas carbamylcholine triggered AT and significantly increased atrial electrical instability. This study reports the occurrence of unprovoked episodes of atrial arrhythmia in hypertensive rats, and their increased incidence with aging. Our results suggest that autonomic imbalance with relative vagal hyperactivity may be responsible for the increased atrial arrhythmogenicity observed in this model. We also provide evidence that, in this model, the sympatho-vagal imbalance preceded the occurrence of arrhythmia. These results indicate that aging SHRs may provide valuable insight into the understanding of atrial arrhythmias.

Heart Rate Variability as an Indicator of Chronic Stress Caused by Lameness in Dairy Cows.

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Levente Kovács

Full Text Available Most experimental studies on animal stress physiology have focused on acute stress, while chronic stress, which is also encountered in intensive dairy cattle farming--e.g. in case of lameness--, has received little attention. We investigated heart rate (HR and heart rate variability (HRV as indicators of the autonomic nervous system activity and fecal glucocorticoid concentrations as the indicator of the hypothalamic-pituitary-adrenal axis activity in lame (with locomotion scores 4 and 5; n = 51 and non-lame (with locomotion scores 1 and 2; n = 52 Holstein-Friesian cows. Data recorded during the periods of undisturbed lying--representing baseline cardiac activity--were involved in the analysis. Besides linear analysis methods of the cardiac inter-beat interval (time-domain geometric, frequency domain and Poincaré analyses non-linear HRV parameters were also evaluated. With the exception of standard deviation 1 (SD1, all HRV indices were affected by lameness. Heart rate was lower in lame cows than in non-lame ones. Vagal tone parameters were higher in lame cows than in non-lame animals, while indices of the sympathovagal balance reflected on a decreased sympathetic activity in lame cows. All geometric and non-linear HRV measures were lower in lame cows compared to non-lame ones suggesting that chronic stress influenced linear and non-linear characteristics of cardiac function. Lameness had no effect on fecal glucocorticoid concentrations. Our results demonstrate that HRV analysis is a reliable method in the assessment of chronic stress, however, it requires further studies to fully understand the elevated parasympathetic and decreased sympathetic tone in lame animals.

A Wearable EEG-HEG-HRV Multimodal System With Simultaneous Monitoring of tES for Mental Health Management.

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Ha, Unsoo; Lee, Yongsu; Kim, Hyunki; Roh, Taehwan; Bae, Joonsung; Kim, Changhyeon; Yoo, Hoi-Jun

2015-12-01

A multimodal mental management system in the shape of the wearable headband and earplugs is proposed to monitor electroencephalography (EEG), hemoencephalography (HEG) and heart rate variability (HRV) for accurate mental health monitoring. It enables simultaneous transcranial electrical stimulation (tES) together with real-time monitoring. The total weight of the proposed system is less than 200 g. The multi-loop low-noise amplifier (MLLNA) achieves over 130 dB CMRR for EEG sensing and the capacitive correlated-double sampling transimpedance amplifier (CCTIA) has low-noise characteristics for HEG and HRV sensing. Measured three-physiology domains such as neural, vascular and autonomic domain signals are combined with canonical correlation analysis (CCA) and temporal kernel canonical correlation analysis (tkCCA) algorithm to find the neural-vascular-autonomic coupling. It supports highly accurate classification with the 19% maximum improvement with multimodal monitoring. For the multi-channel stimulation functionality, after-effects maximization monitoring and sympathetic nerve disorder monitoring, the stimulator is designed as reconfigurable. The 3.37 × 2.25 mm(2) chip has 2-channel EEG sensor front-end, 2-channel NIRS sensor front-end, NIRS current driver to drive dual-wavelength VCSEL and 6-b DAC current source for tES mode. It dissipates 24 mW with 2 mA stimulation current and 5 mA NIRS driver current.

Cardiac autonomic profile in different sports disciplines during all-day activity.

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Sztajzel, J; Jung, M; Sievert, K; Bayes De Luna, A

2008-12-01

Physical training and sport activity have a beneficial effect on cardiac autonomic activity. However, the exact impact of different types of sports disciplines on cardiac autonomic function is still unclear. The aim of this study was to evaluate the cardiac autonomic profile in different sports discplines and to determine their impact on cardiac autonomic function by using heart rate variability (HRV), a noninvasive electrocardiographic (ECG) analysis of the sympatho-vagal balance. Temporal and spectral HRV parameters determined from 24-hour continuous ECG monitoring were studied in 40 subjects, including 12 endurance athletes, 14 hockey players and 14 untrained male volunteers (control group). Each participant had to wear a Holter recorder during 24 hours and to continue his everyday activities. All HRV parameters were compared between the 3 study groups. All heart rate values were lower and all parasympathetic-related time domain indices, including root mean square of successive differences (RMSSD) and pNN50 (NN50 count divided by the total number of all NN intervals), were higher in both athletes groups as compared with controls (PHRV, were significantly higher only in endurance athletes (PHRV (higher SDNN), indicating thereby that this type sports discipline may have a more substantially favorable effect on the cardiac autonomic profile.

Different role of TTX-sensitive voltage-gated sodium channel (NaV 1) subtypes in action potential initiation and conduction in vagal airway nociceptors.

Science.gov (United States)

Kollarik, M; Sun, H; Herbstsomer, R A; Ru, F; Kocmalova, M; Meeker, S N; Undem, B J

2018-04-15

The action potential initiation in the nerve terminals and its subsequent conduction along the axons of afferent nerves are not necessarily dependent on the same voltage-gated sodium channel (Na V 1) subunits. The action potential initiation in jugular C-fibres within airway tissues is not blocked by TTX; nonetheless, conduction of action potentials along the vagal axons of these nerves is often dependent on TTX-sensitive channels. This is not the case for nodose airway Aδ-fibres and C-fibres, where both action potential initiation and conduction is abolished by TTX or selective Na V 1.7 blockers. The difference between the initiation of action potentials within the airways vs. conduction along the axons should be considered when developing Na V 1 blocking drugs for topical application to the respiratory tract. The action potential (AP) initiation in the nerve terminals and its subsequent AP conduction along the axons do not necessarily depend on the same subtypes of voltage-gated sodium channels (Na V 1s). We evaluated the role of TTX-sensitive and TTX-resistant Na V 1s in vagal afferent nociceptor nerves derived from jugular and nodose ganglia innervating the respiratory system. Single cell RT-PCR was performed on vagal afferent neurons retrogradely labelled from the guinea pig trachea. Almost all of the jugular neurons expressed the TTX-sensitive channel Na V 1.7 along with TTX-resistant Na V 1.8 and Na V 1.9. Tracheal nodose neurons also expressed Na V 1.7 but, less frequently, Na V 1.8 and Na V 1.9. Na V 1.6 were expressed in ∼40% of the jugular and 25% of nodose tracheal neurons. Other Na V 1 α subunits were only rarely expressed. Single fibre recordings were made from the vagal nodose and jugular nerve fibres innervating the trachea or lung in the isolated perfused vagally-innervated preparations that allowed for selective drug delivery to the nerve terminal compartment (AP initiation) or to the desheathed vagus nerve (AP conduction). AP initiation in

Seasonal Variations in Heart Rate Variability as an Indicator of Stress in Free-Ranging Pregnant Przewalski's Horses (E. ferus przewalskii within the Hortobágy National Park in Hungary

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Friederike Pohlin

2017-09-01

Full Text Available Background: Ecosystems with seasonal fluctuations in climate and food availability present physiological challenges to resident mammals and may cause “stress.” The two predominant physiological responses to stressors are (1 the activation of the hypothalamic-pituitary-adrenal axis and (2 the modulation of the autonomic nervous system. To date, the primary indicator for “stress” in wildlife- and zoo animal research are glucocorticoid levels. By measuring the autonomic regulation of cardiac activity, particularly the vagal tone, heart rate variability (HRV is presently emerging as a suitable indicator of “stress” in farm- and domestic animal research.Objective: The aim of this study was to use HRV, a novel method in wildlife research, to assess seasonal patterns of “stress” in a group of free-ranging Przewalski's horses (Equus ferus przewalskii.Methods: Six pregnant Przewalski's horses from one harem within the Hortobágy National Park in Hungary were subjected to the study. We used a dedicated telemetry system consisting of a subcutaneously implanted transmitter and a receiver and storage unit in a collar to record HRV, heart rate (HR, subcutaneous body temperature, and activity throughout a one-year study period—climate data was also collected. We defined “stress” as a decrease in parasympathetic nervous system tone and calculated RMSSD (root mean square of successive differences as a measure of HRV. Linear mixed effects models with random intercept per individual were used for statistical analysis.Results: HRV and HR varied considerably throughout the year. Similar to temperate ruminants and hibernating mammals, Przewalski's horses experienced lower HR and HRV during winter, when resources are limited indicating decreased metabolic rates coupled with “stress.” In spring, we observed a drop of HRV along with a peak in HR indicating an increase of allostatic load that is most likely associated with increased energy

The link between negative affect, vagal tone, and visceral sensitivity in quiescent Crohn's disease.

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Rubio, A; Pellissier, S; Picot, A; Dantzer, C; Bonaz, B

2014-08-01

Autonomic dysfunction and mood disorders are frequently described in Crohn's disease (CD) and are known to influence visceral sensitivity. We addressed the link between vagal tone, negative affect, and visceral sensitivity in CD patients without concomitant features of irritable bowel syndrome (IBS). Rectal distensions to a discomfort threshold of 70% and onset of pain were performed in nine CD patients in remission and eight healthy controls. Autonomic parameters were evaluated with heart rate variability and electrodermal reactivity. We showed that CD patients had (i) higher scores of depressive symptomatology (12 ± 3 in patients vs 4 ± 1 in controls on the Center for Epidemiologic Studies-Depression Scale; p = 0.038), (ii) reduced vagal tone (HF 257 ± 84 ms(2) vs 1607 ± 1032 ms(2) , p = 0.043; LF 455 ± 153 ms(2) vs 1629 ± 585 ms(2) , p = 0.047), (iii) decreased sympathetic reactivity during an aversive stimulus, and (iv) higher tolerance to rectal distension pressures (43 ± 3 mmHg vs 30 ± 2 mmHg, p = 0.002) and low sensitivity index scores. In conclusion, our results provide preliminary evidence that patients with quiescent CD, in the absence of IBS, are hyposensate to experimental rectal distension. These data provide further evidence that anxiety and depressive symptomatology in addition to autonomic dysfunction modulate visceral pain perception in quiescent CD patients in the absence of IBS. © 2014 John Wiley & Sons Ltd.

Growth and characterization of different human rhinovirus C types in three-dimensional human airway epithelia reconstituted in vitro

International Nuclear Information System (INIS)

Tapparel, Caroline; Sobo, Komla; Constant, Samuel; Huang, Song; Van Belle, Sandra; Kaiser, Laurent

2013-01-01

New molecular diagnostic tools have recently allowed the discovery of human rhinovirus species C (HRV-C) that may be overrepresented in children with lower respiratory tract complications. Unlike HRV-A and HRV-B, HRV-C cannot be propagated in conventional immortalized cell lines and their biological properties have been difficult to study. Recent studies have described the successful amplification of HRV-C15, HRV-C11, and HRV-C41 in sinus mucosal organ cultures and in fully differentiated human airway epithelial cells. Consistent with these studies, we report that a panel of clinical HRV-C specimens including HRV-C2, HRV-C7, HRV-C12, HRV-C15, and HRV-C29 types were all capable of mediating productive infection in reconstituted 3D human primary upper airway epithelial tissues and that the virions enter and exit preferentially through the apical surface. Similar to HRV-A and HRV-B, our data support the acid sensitivity of HRV-C. We observed also that the optimum temperature requirement during HRV-C growth may be type-dependent. - Highlights: • A 3D human upper airway epithelia reconstituted in vitro supports HRV-C growth. • HRV-Cs enter and exit preferentially at the apical side of this ALI culture system. • HRV-Cs are acid sensitive. • Temperature sensitivity may be type-dependent for HRV-Cs

Growth and characterization of different human rhinovirus C types in three-dimensional human airway epithelia reconstituted in vitro

Energy Technology Data Exchange (ETDEWEB)

Tapparel, Caroline, E-mail: Caroline.Tapparel@hcuge.ch [Laboratory of Virology, Division of Infectious Diseases and Division of Laboratory Medicine, University of Geneva Hospitals, 4 Rue Gabrielle-Perret-Gentil, 1211 Geneva 14 (Switzerland); Sobo, Komla [Laboratory of Virology, Division of Infectious Diseases and Division of Laboratory Medicine, University of Geneva Hospitals, 4 Rue Gabrielle-Perret-Gentil, 1211 Geneva 14 (Switzerland); Constant, Samuel; Huang, Song [Epithelix sárl, 14 Chemin des Aulx, 1228 Plan les Ouates, Geneva (Switzerland); Van Belle, Sandra; Kaiser, Laurent [Laboratory of Virology, Division of Infectious Diseases and Division of Laboratory Medicine, University of Geneva Hospitals, 4 Rue Gabrielle-Perret-Gentil, 1211 Geneva 14 (Switzerland)

2013-11-15

New molecular diagnostic tools have recently allowed the discovery of human rhinovirus species C (HRV-C) that may be overrepresented in children with lower respiratory tract complications. Unlike HRV-A and HRV-B, HRV-C cannot be propagated in conventional immortalized cell lines and their biological properties have been difficult to study. Recent studies have described the successful amplification of HRV-C15, HRV-C11, and HRV-C41 in sinus mucosal organ cultures and in fully differentiated human airway epithelial cells. Consistent with these studies, we report that a panel of clinical HRV-C specimens including HRV-C2, HRV-C7, HRV-C12, HRV-C15, and HRV-C29 types were all capable of mediating productive infection in reconstituted 3D human primary upper airway epithelial tissues and that the virions enter and exit preferentially through the apical surface. Similar to HRV-A and HRV-B, our data support the acid sensitivity of HRV-C. We observed also that the optimum temperature requirement during HRV-C growth may be type-dependent. - Highlights: • A 3D human upper airway epithelia reconstituted in vitro supports HRV-C growth. • HRV-Cs enter and exit preferentially at the apical side of this ALI culture system. • HRV-Cs are acid sensitive. • Temperature sensitivity may be type-dependent for HRV-Cs.

Heart rate variability and the relationship between trauma exposure age, and psychopathology in a post-conflict setting.

Science.gov (United States)

Liddell, Belinda J; Kemp, Andrew H; Steel, Zachary; Nickerson, Angela; Bryant, Richard A; Tam, Natalino; Tay, Alvin Kuowei; Silove, Derrick

2016-05-10

Cumulative exposure to potentially traumatic events (PTEs) increases risk for mental distress in conflict-affected settings, but the psychophysiological mechanisms that mediate this dose-response relationship are unknown. We investigated diminished heart rate variability (HRV) - an index of vagus nerve function and a robust predictor of emotion regulation capacity - as a vulnerability marker that potentially mediates the association between PTE exposure, age and symptoms of posttraumatic stress disorder (PTSD), psychological distress and aggressive behavior, in a community sample from Timor-Leste - a post-conflict country with a history of mass violence. Resting state heart rate data was recorded from 45 cases of PTSD, depression and intermittent explosive disorder (IED); and 29 non-case controls. Resting HRV was significantly reduced in the combined case group compared with non-cases (p = .021; Cohen's d = 0.5). A significant mediation effect was also observed, whereby a sequence of increased age, reduced HRV and elevated PTSD symptoms mediated the association between PTE exposure and distress (B = .06, SE = .05, 95% CI = [.00-.217]) and aggression (B = .02, SE = .02, 95% CI = [.0003-.069])). The findings demonstrate an association between diminished resting HRV and psychopathology. Moreover, age-related HRV reductions emerged as a potential psychophysiological mechanism that underlies enhanced vulnerability to distress and aggression following cumulative PTE exposure.

Improvements in well-being and vagal tone following a yogic breathing-based life skills workshop in young adults: Two open-trial pilot studies

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Michael R Goldstein

2016-01-01

Conclusions: These findings suggest that a life skills workshop integrating yogic breathing techniques may provide self-empowering tools for enhancing well-being in young adults. Future research is indicated to further explore these effects, particularly in regards to vagal tone and other aspects of stress physiology.

Neuro-immune relationships at patients with chronic pyelonephrite and cholecystite. Communication 2. Correlations between parameters EEG, HRV and Phagocytosis

OpenAIRE

Kul’chyns’kyi, Andriy B; Kovbasnyuk, Marta M; Korolyshyn, Tetyana A; Kyjenko, Valeriy M; Zukow, Walery; Popovych, Igor L

2016-01-01

Kul’chyns’kyi Andriy B, Kovbasnyuk Marta M, Korolyshyn Tetyana A, Kyjenko Valeriy M, Zukow Walery, Popovych Igor L. Neuro-immune relationships at patients with chronic pyelonephrite and cholecystite. Communication 2. Correlations between parameters EEG, HRV and Phagocytosis. Journal of Education, Health and Sport. 2016;6(10):377-401. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.163221 http://ojs.ukw.edu.pl/index.php/johs/article/view/3957 The journal h...

The influence of resistance exercise with emphasis on specific contractions (concentric vs. eccentric on muscle strength and post-exercise autonomic modulation: a randomized clinical trial

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Mariana O. Gois

2014-01-01

Full Text Available Background: Compared to eccentric contractions, concentric contractions result in higher cardiovascular stress. However, we do not know how these two types of contractions influence cardiac autonomic modulation during the post-exercise recovery period. Objective: to compare the effect of resistance training that is performed with concentric vs. eccentric emphasis on muscle strength and on post-exercise recovery which was assessed by examining heart rate variability (HRV, for the knee extensor muscle group in young healthy adults. Methods: For this study, 105 men between 18 and 30 years of age were randomized into 4 groups: concentric control (CONCC, eccentric control (ECCC, concentric training (CONCT and eccentric training (ECCT. The CONCC and ECCC groups underwent one session of resistance exercise (RE using the knee extensor muscle group (3 sets of 1 repetition at 100% of the maximal repetition [1MR] and the CONCT and ECCT groups performed 10 training sessions. The HRV was analyzed at baseline and across four recovery periods (T1, T2, T3 and T4. Results: The ECCT group exhibited increased muscle strength at the end of the study. Regarding cardiac autonomic modulation, the CONCC and ECCC groups exhibited increases in overall variability (SDNN and SD2 at T1 compared to baseline, and the ECCT group demonstrated increases in variables reflecting vagal modulation and the recovery process (RMSSD, SD1 and HF [ms2] at T1, T2 and T4 compared to baseline. Conclusions: Resistance training with emphasis on eccentric contractions promoted strength gain and an increase in cardiac vagal modulation during recovery compared to baseline.

Comparison of spontaneous vs. metronome-guided breathing on assessment of vagal modulation using RR variability.

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Bloomfield, D M; Magnano, A; Bigger, J T; Rivadeneira, H; Parides, M; Steinman, R C

2001-03-01

R-R interval variability (RR variability) is increasingly being used as an index of autonomic activity. High-frequency (HF) power reflects vagal modulation of the sinus node. Since vagal modulation occurs at the respiratory frequency, some investigators have suggested that HF power cannot be interpreted unless the breathing rate is controlled. We hypothesized that HF power during spontaneous breathing would not differ significantly from HF power during metronome-guided breathing. We measured HF power during spontaneous breathing in 20 healthy subjects and 19 patients with heart disease. Each subject's spontaneous breathing rate was determined, and the calculation of HF power was repeated with a metronome set to his or her average spontaneous breathing rate. There was no significant difference between the logarithm of HF power measured during spontaneous and metronome-guided breathing [4.88 +/- 0.29 vs. 5.29 +/- 0.30 ln(ms(2)), P = 0.32] in the group as a whole and when patients and healthy subjects were examined separately. We did observe a small (9.9%) decrease in HF power with increasing metronome-guided breathing rates (from 9 to 20 breaths/min). These data indicate that HF power during spontaneous and metronome-guided breathing differs at most by very small amounts. This variability is several logarithmic units less than the wide discrepancies observed between healthy subjects and cardiac patients with a heterogeneous group of cardiovascular disorders. In addition, HF power is relatively constant across the range of typical breathing rates. These data indicate that there is no need to control breathing rate to interpret HF power when RR variability (and specifically HF power) is used to identify high-risk cardiac patients.

Lung vagal afferent activity in rats with bleomycin-induced lung fibrosis.

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Schelegle, E S; Walby, W F; Mansoor, J K; Chen, A T

2001-05-01

Bleomycin treatment in rats results in pulmonary fibrosis that is characterized by a rapid shallow breathing pattern, a decrease in quasi-static lung compliance and a blunting of the Hering-Breuer Inflation Reflex. We examined the impulse activity of pulmonary vagal afferents in anesthetized, mechanically ventilated rats with bleomycin-induced lung fibrosis during the ventilator cycle and static lung inflations/deflations and following the injection of capsaicin into the right atrium. Bleomycin enhanced volume sensitivity of slowly adapting stretch receptors (SARs), while it blunted the sensitivity of these receptors to increasing transpulmonary pressure. Bleomycin treatment increased the inspiratory activity, while it decreased the expiratory activity of rapidly adapting stretch receptors (RARs). Pulmonary C-fiber impulse activity did not appear to be affected by bleomycin treatment. We conclude that the fibrosis-related shift in discharge profile and enhanced volume sensitivity of SARs combined with the increased inspiratory activity of RARs contributes to the observed rapid shallow breathing of bleomycin-induced lung fibrosis.

Characterization of doctor-patient communication using heartbeat nonlinear dynamics: A preliminary study using Lagged Poincaré Plots.

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Nardelli, M; Del Piccolo, L; Danzi, Op; Perlini, C; Tedeschi, F; Greco, A; Scilingo, Ep; Valenza, G

2017-07-01

Emphatic doctor-patient communication has been associated with an improved psycho-physiological well-being involving cardiovascular and neuroendocrine responses. Nevertheless, a comprehensive assessment of heartbeat linear and nonlinear/complex dynamics throughout the communication of a life-threatening disease has not been performed yet. To this extent, we here study heart rate variability (HRV) series gathered from 17 subjects while watching a video where an oncologist discloses the diagnosis of a cancer metastasis to a patient. Further 17 subjects watched the same video including additional affective emphatic contents. For the assessment of the two groups, linear heartbeat dynamics was quantified through measures defined in the time and frequency domains, whereas nonlinear/complex dynamics referred to measures of entropy, and combined Lagged Poincare Plots (LPP) and symbolic analyses. Considering differences between the beginning and the end of the video, results from non-parametric statistical tests demonstrated that the group watching emphatic contents showed HRV changes in the LF/HF ratio exclusively. Conversely, the group watching the purely informative video showed changes in vagal activity (i.e., HF power), LF/HF ratio, as well as LPP measures. Additionally, a Support Vector Machine algorithm including HRV nonlinear/complex information was able to automatically discern between groups with an accuracy of 76.47%. We therefore propose the use of heartbeat nonlinear/complex dynamics to objectively assess the empathy level of healthy women.

Omega-3 Fatty Acid Supplementation Improves Heart Rate Variability in Obese Children

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Christoph Baumann

2018-01-01

Full Text Available Obese children and adolescents are at high risk of developing cardiovascular diseases later in life. We hypothesized that cardiovascular prophylaxis with omega-3 fatty acids could benefit them. In our study, 20 children and adolescents (mean body mass index percentile: 99.1; mean age: 11.0 years underwent two ambulatory 24 h Holter electrocardiography (ECG recordings (before and after at least 3 months of omega-3 fatty acid supplementation. Time domain heart rate variability (HRV and heart rate (HR were examined for these patients. As a control, we used 24 h Holter ECG recordings of 94 nonobese children and adolescents. Time domain HRV parameters, which are indicators of vagal stimulation, were significantly lower in obese patients than in healthy controls, but HR was higher (standard deviation of the normal-to-normal [SDNN] interbeat intervals: −34.02%; root mean square of successive differences [RMSSD] between normal heartbeats: −40.66%; percentage of consecutive RR intervals [pNN50]: −60.24%; HR: +13.37%. After omega-3 fatty acid supplementation, time domain HRV parameters and HR of obese patients were similar to the values of healthy controls (SDNN interbeat intervals: −21.73%; RMSSD: −19.56%; pNN50: −25.59%; HR: +3.94%. Therefore, omega-3 fatty acid supplementation may be used for cardiovascular prophylaxis in obese children and adolescents.

Dorsal Vagal Complex Modulates Neurogenic Airway Inflammation in a Guinea Pig Model With Esophageal Perfusion of HCl

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Zhe Chen

2018-05-01

Full Text Available Neurogenic airway inflammation in chronic cough and bronchial asthma related to gastroesophageal reflux (GER is involved in the esophageal–bronchial reflex, but it is unclear whether this reflex is mediated by central neurons. This study aimed to investigate the regulatory effects of the dorsal vagal complex (DVC on airway inflammation induced by the esophageal perfusion of hydrochloric acid (HCl following the microinjection of nuclei in the DVC in guinea pigs. Airway inflammation was evaluated by measuring the extravasation of Evans blue dye (EBD and substance P (SP expression in the airway. Neuronal activity was indicated by Fos expression in the DVC. The neural pathways from the lower esophagus to the DVC and the DVC to the airway were identified using DiI tracing and pseudorabies virus Bartha (PRV-Bartha retrograde tracing, respectively. HCl perfusion significantly increased plasma extravasation, SP expression in the trachea, and the expression of SP and Fos in the medulla oblongata nuclei, including the nucleus of the solitary tract (NTS and the dorsal motor nucleus of the vagus (DMV. The microinjection of glutamic acid (Glu or exogenous SP to enhance neuronal activity in the DVC significantly potentiated plasma extravasation and SP release induced by intra-esophageal perfusion. The microinjection of γ-aminobutyric acid (GABA, lidocaine to inhibit neuronal activity or anti-SP serum in the DVC alleviated plasma extravasation and SP release. In conclusion, airway inflammation induced by the esophageal perfusion of HCl is regulated by DVC. This study provides new insight for the mechanism of airway neurogenic inflammation related to GER.

Parasympathetic neurons in the cranial medial ventricular fat pad on the dog heart selectively decrease ventricular contractility.

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Dickerson, L W; Rodak, D J; Fleming, T J; Gatti, P J; Massari, V J; McKenzie, J C; Gillis, R A

1998-05-28

We hypothesized that selective control of ventricular contractility might be mediated by postganglionic parasympathetic neurons in the cranial medial ventricular (CMV) ganglion plexus located in a fat pad at the base of the aorta. Sinus rate, atrioventricular (AV) conduction (ventricular rate during atrial pacing), and left ventricular contractile force (LV dP/dt during right ventricular pacing) were measured in eight chloralose-anesthetized dogs both before and during bilateral cervical vagus stimulation (20-30 V, 0.5 ms pulses, 15-20 Hz). Seven of these dogs were tested under beta-adrenergic blockade (propranolol, 0.8 mg kg(-1) i.v.). Control responses included sinus node bradycardia or arrest during spontaneous rhythm, high grade AV block or complete heart block, and a 30% decrease in contractility from 2118 +/- 186 to 1526 +/- 187 mm Hg s(-1) (P 0.05) decrease in contractility but still elicited the same degree of sinus bradycardia and AV block (N = 8, P < 0.05). Five dogs were re-tested 3 h after trimethaphan fat pad injection, at which time blockade of vagally-induced negative inotropy was partially reversed, as vagal stimulation decreased LV dP/dt by 19%. The same dose of trimethaphan given either locally into other fat pads (PVFP or IVC-ILA) or systemically (i.v.) had no effect on vagally-induced negative inotropy. Thus, parasympathetic ganglia located in the CMV fat pad mediated a decrease in ventricular contractility during vagal stimulation. Blockade of the CMV fat pad had no effect on vagally-mediated slowing of sinus rate or AV conduction.

Mechanism of hyperphagia contributing to obesity in brain-derived neurotrophic factor knockout mice.

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Fox, E A; Biddinger, J E; Jones, K R; McAdams, J; Worman, A

2013-01-15

Global-heterozygous and brain-specific homozygous knockouts (KOs) of brain-derived neurotrophic factor (BDNF) cause late- and early-onset obesity, respectively, both involving hyperphagia. Little is known about the mechanism underlying this hyperphagia or whether BDNF loss from peripheral tissues could contribute to overeating. Since global-homozygous BDNF-KO is perinatal lethal, a BDNF-KO that spared sufficient brainstem BDNF to support normal health was utilized to begin to address these issues. Meal pattern and microstructure analyses suggested overeating of BDNF-KO mice was mediated by deficits in both satiation and satiety that resulted in increased meal size and frequency and implicated a reduction of vagal signaling from the gut to the brain. Meal-induced c-Fos activation in the nucleus of the solitary tract, a more direct measure of vagal afferent signaling, however, was not decreased in BDNF-KO mice, and thus was not consistent with a vagal afferent role. Interestingly though, meal-induced c-Fos activation was increased in the dorsal motor nucleus of the vagus nerve (DMV) of BDNF-KO mice. This could imply that augmentation of vago-vagal digestive reflexes occurred (e.g., accommodation), which would support increased meal size and possibly increased meal number by reducing the increase in intragastric pressure produced by a given amount of ingesta. Additionally, vagal sensory neuron number in BDNF-KO mice was altered in a manner consistent with the increased meal-induced activation of the DMV. These results suggest reduced BDNF causes satiety and satiation deficits that support hyperphagia, possibly involving augmentation of vago-vagal reflexes mediated by central pathways or vagal afferents regulated by BDNF levels. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

[The role of the autonomic nervous system on malfunction of gastric motor and myoelectric activity in patients with hyperthyroidism].

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Barczyński, M; Thor, P J; Słowiaczek, M; Pitala, A

2000-01-01

relative sympathetic activation. In HRV analysis during deep breathing test the decrease of heart rate variability was present mostly in LF component. It indicates on reduction of vagal regulation (and vagal excitability) of sinus node and gastric pacemaker function. Coexistence of the increase and decrease of a gastric basic electrical rhythm with delay of gastric emptying indicates on a complex mechanism of their formation. Both neurogenic regulation dysfunction and primary miogenic autoregulation disorders as a result of tyreotoxicosis seem to be the possible causes. All the found changes were functional and disappeared after reaching the stable euthyroid state within 3 months of pharmacological treatment.

Effects of Weekly Low-Frequency rTMS on Autonomic Measures in Children with Autism Spectrum Disorder

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Manuel Fernando Casanova

2014-10-01

Full Text Available The term autism spectrum disorder (ASD describes a range of conditions characterized by impairments in social interactions, communication, and by restricted and repetitive behaviors. ASD may also present with symptoms suggestive of autonomic nervous system (ANS dysfunction. The objective of this study was to determine the effect of 18 sessions of low frequency repetitive transcranial magnetic stimulation (rTMS on autonomic function in children with ASD by recording electrocardiogram (EKG and electrodermal activity pre-, post- and during each rTMS session. The autonomic measures of interest in this study were R-R cardiointervals in EKG (R-R, time and frequency domain measures of heart rate variability (HRV and skin conductance level (SCL. HRV measures such as R-R intervals, standard deviation of cardiac intervals, pNN50 (percentage of cardiointervals>50 ms different from preceding interval, power of high frequency (HF and low frequency (LF components of HRV spectrum, LF/HF ratio, were then derived from the recorded EKG. We expected that the course of 18 weekly inhibitory low-frequency rTMS applied to the dorsolateral prefrontal cortex (DLPFC would enhance autonomic balance by facilitating frontal inhibition of limbic activity thus resulting in decreased overall heart rate, increased HRV (in a form of increased HF power, decreased LF power (resulting in decreased LF/HF ratio, and decreased SCL. Behavioral evaluations post-18 TMS showed decreased irritability, hyperactivity, stereotype behavior and compulsive behavior ratings while autonomic measures indicated a significant increase in cardiac interval variability and a decrease of tonic SCL. The results suggest that 18 sessions of low frequency rTMS in ASD results in increased cardiac vagal control and reduced sympathetic arousal.

Effects of citalopram on heart rate variability in women with generalized anxiety disorder

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Fatemeh Ranjbar

2015-07-01

Full Text Available BACKGROUND: Heart rate variability (HRV is defined as variations in R-R interval with time. Dysautonomia is common in patients with psychiatric disorders such as depression and anxiety. Using HRV analysis, recent studies showed that in anxiety disorders, the vagal cardiac function decreases, and sympathetic function increases. This study aimed at investigating citalopram effects on HRV. METHODS: This before and after study was conducted in 25 generalized anxiety disorder (GAD patients. GAD was diagnosed based on clinical interview according to diagnostic and statistical manual of mental disorders IV-Text revised (DSM-IV-TR criteria using Structured Clinical Interview for DSM Disorders-I questionnaire. A cardiologist studied 24 h ambulatory monitoring of the electrocardiogram (Holter on all patients before the treatment. A volume of 20 mg of citalopram was administered to the subjects on a daily basis. Then, they were studied by Holter monitoring again after 1-month of administration of citalopram. RESULTS: The average age of participants was 35.32 ± 8.7. The average Holter monitoring time was 23.29 ± 1.14 h before treatment and 23.81 ± 0.68 after it. The 3 h low frequency/high frequency ratio was significantly different between 3 h segments of time before treatment (P < 0.001. This difference was even higher after treatment (P = 0.001. Data showed an increase in parasympathetic tone during sleep both before and after treatment. CONCLUSION: These patients showed some impairments of HRV indices that did not improve by citalopram in future, the clinical importance of such disturbances should be evaluated in details with prolonged follow-up and greater sample size.   

NMDA Receptor-Dependent Synaptic Activity in Dorsal Motor Nucleus of Vagus Mediates the Enhancement of Gastric Motility by Stimulating ST36

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Xinyan Gao

2012-01-01

Full Text Available Previous studies have demonstrated the efficacy of electroacupuncture at ST36 for patients with gastrointestinal motility disorders. While several lines of evidence suggest that the effect may involve vagal reflex, the precise molecular mechanism underlying this process still remains unclear. Here we report that the intragastric pressure increase induced by low frequency electric stimulation at ST36 was blocked by AP-5, an antagonist of N-methyl-D-aspartate receptors (NMDARs. Indeed, stimulating ST36 enhanced NMDAR-mediated, but not 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-ylpropanoic-acid-(AMPA- receptor-(AMPAR- mediated synaptic transmission in gastric-projecting neurons of the dorsal motor nucleus of the vagus (DMV. We also identified that suppression of presynaptic μ-opioid receptors may contribute to upregulation of NMDAR-mediated synaptic transmission induced by electroacupuncture at ST36. Furthermore, we determined that the glutamate-receptor-2a-(NR2A- containing NMDARs are essential for NMDAR-mediated enhancement of gastric motility caused by stimulating ST36. Taken together, our results reveal an important role of NMDA receptors in mediating enhancement of gastric motility induced by stimulating ST36.

The expression profile of acid-sensing ion channel (ASIC) subunits ASIC1a, ASIC1b, ASIC2a, ASIC2b, and ASIC3 in the esophageal vagal afferent nerve subtypes.

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Dusenkova, Svetlana; Ru, Fei; Surdenikova, Lenka; Nassenstein, Christina; Hatok, Jozef; Dusenka, Robert; Banovcin, Peter; Kliment, Jan; Tatar, Milos; Kollarik, Marian

2014-11-01

Acid-sensing ion channels (ASICs) have been implicated in esophageal acid sensing and mechanotransduction. However, insufficient knowledge of ASIC subunit expression profile in esophageal afferent nerves hampers the understanding of their role. This knowledge is essential because ASIC subunits form heteromultimeric channels with distinct functional properties. We hypothesized that the esophageal putative nociceptive C-fiber nerves (transient receptor potential vanilloid 1, TRPV1-positive) express multiple ASIC subunits and that the ASIC expression profile differs between the nodose TRPV1-positive subtype developmentally derived from placodes and the jugular TRPV1-positive subtype derived from neural crest. We performed single cell RT-PCR on the vagal afferent neurons retrogradely labeled from the esophagus. In the guinea pig, nearly all (90%-95%) nodose and jugular esophageal TRPV1-positive neurons expressed ASICs, most often in a combination (65-75%). ASIC1, ASIC2, and ASIC3 were expressed in 65-75%, 55-70%, and 70%, respectively, of both nodose and jugular TRPV1-positive neurons. The ASIC1 splice variants ASIC1a and ASIC1b and the ASIC2 splice variant ASIC2b were similarly expressed in both nodose and jugular TRPV1-positive neurons. However, ASIC2a was found exclusively in the nodose neurons. In contrast to guinea pig, ASIC3 was almost absent from the mouse vagal esophageal TRPV1-positive neurons. However, ASIC3 was similarly expressed in the nonnociceptive TRPV1-negative (tension mechanoreceptors) neurons in both species. We conclude that the majority of esophageal vagal nociceptive neurons express multiple ASIC subunits. The placode-derived nodose neurons selectively express ASIC2a, known to substantially reduce acid sensitivity of ASIC heteromultimers. ASIC3 is expressed in the guinea pig but not in the mouse vagal esophageal TRPV1-positive neurons, indicating species differences in ASIC expression. Copyright © 2014 the American Physiological Society.

Vagal cardiac control throughout the day : the relative importance of effort-reward imbalance and within-day measurements of mood, demand and satisfaction

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Hanson, E.; Godaert, G.L R; Maas, C.J.M.; Meijman, T.F.

The effects of variables derived from a work stress theory (the effort-reward imbalance theory) on the power in the high frequency (HF_HRV) band of heart rate (0.14-0.40 Hz) throughout a work day, were determined using multilevel analysis. Explanatory variables were analysed at two levels: at the

Eating Habits and Food Additive Intakes Are Associated with Emotional States Based on EEG and HRV in Healthy Korean Children and Adolescents.

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Kim, Jin Young; Kang, Hye Lim; Kim, Dae-Keun; Kang, Seung Wan; Park, Yoo Kyoung

2017-07-01

Recent study suggests that psychological issues and eating habits are closely related. In this study, we aimed to find the association between eating habits and intakes of artificial sweeteners with emotional states of schoolchildren using quantitatively analyzing objective biosignals. The study was conducted at the National Standard Reference Data Center for Korean EEG as a cross-sectional study. Three hundred eighteen healthy children who have not been diagnosed with neurologic or psychiatric disorders were evaluated (168 girls and 150 boys; mean age of 11.8 ± 3.6 years). Analysis indicators were a dietary intake checklist for children's nutrition-related behavior score (NBS), consisting of 19 items; food frequency questionnaires (FFQs), consisting of 76 items; the Child Depression Inventory (CDI); State-Trait Anxiety Inventory-State (STAI-S); State-Trait Anxiety Inventory-Trait (STAI-T); electroencephalograph (EEG); and heart rate variability (HRV). Higher scores on the CDI, STAI-S, and STAI-T indicate negative emotions, and these scores were significantly decreased from the first to the fourth quartiles. The HRV results showed that the standard deviation of all normal-to-normal (SDNN) intervals was significantly higher in the first quartile than in the fourth quartile (p healthy children and adolescents.

Newly divided eosinophils limit ozone-induced airway hyperreactivity in nonsensitized guinea pigs.

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Wicher, Sarah A; Jacoby, David B; Fryer, Allison D

2017-06-01

Ozone causes vagally mediated airway hyperreactivity and recruits inflammatory cells, including eosinophils, to lungs, where they mediate ozone-induced hyperreactivity 1 day after exposure but are paradoxically protective 3 days later. We aimed to test the role of newly divided eosinophils in ozone-induced airway hyperreactivity in sensitized and nonsensitized guinea pigs. Nonsensitized and sensitized guinea pigs were treated with 5-bromo-2-deoxyuridine (BrdU) to label newly divided cells and were exposed to air or ozone for 4 h. Later (1 or 3 days later), vagally induced bronchoconstriction was measured, and inflammatory cells were harvested from bone marrow, blood, and bronchoalveolar lavage. Ozone induced eosinophil hematopoiesis. One day after ozone, mature eosinophils dominate the inflammatory response and potentiate vagally induced bronchoconstriction. However, by 3 days, newly divided eosinophils have reached the lungs, where they inhibit ozone-induced airway hyperreactivity because depleting them with antibody to IL-5 or a TNF-α antagonist worsened vagally induced bronchoconstriction. In sensitized guinea pigs, both ozone-induced eosinophil hematopoiesis and subsequent recruitment of newly divided eosinophils to lungs 3 days later failed to occur. Thus mature eosinophils dominated the ozone-induced inflammatory response in sensitized guinea pigs. Depleting these mature eosinophils prevented ozone-induced airway hyperreactivity in sensitized animals. Ozone induces eosinophil hematopoiesis and recruitment to lungs, where 3 days later, newly divided eosinophils attenuate vagally mediated hyperreactivity. Ozone-induced hematopoiesis of beneficial eosinophils is blocked by a TNF-α antagonist or by prior sensitization. In these animals, mature eosinophils are associated with hyperreactivity. Thus interventions targeting eosinophils, although beneficial in atopic individuals, may delay resolution of airway hyperreactivity in nonatopic individuals. Copyright �

Combinatorial effect of nicotine and black tea on heart rate variability: Useful or harmful?

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Joukar, S; Sheibani, M

2017-06-01

The effect of nicotine on heart rate variability (HRV) is controversial. Autonomic nervous system is the main regulator of heart rhythm, and heart rate variability is an appropriate index to assessment of the effects of the autonomic system on heart. In this study, the combination effect of nicotine and black tea consumption on sympatho-vagal balance and heart rate variability was investigated in rats. Male Wistar rats were randomized into four groups as control, tea (2.5 g/100 cc, daily), nicotine (2 mg/kg/d) and tea plus nicotine groups which treated for 28 days, and in the 29th day, their electrocardiograms (lead II) were recorded. The mean of high-frequency power (HF) in tea, nicotine and tea plus nicotine groups was significantly more than control group (P nicotine and tea + nicotine groups was significantly less than control group (P nicotine and tea + nicotine groups in comparison with control group (P nicotine or their combination with dosages used in this study can increase the heart rate variability and improve the sympatho-vagal balance in rat. © 2017 John Wiley & Sons Ltd.

Does vagal nerve stimulation affect body composition and metabolism? Experimental study of a new potential technique in bariatric surgery.

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Sobocki, Jacek; Fourtanier, Gilles; Estany, Joan; Otal, Phillipe

2006-02-01

It has been shown that vagal nerve stimulation (VNS) can affect body mass. The aim of this study was to evaluate effect of VNS on body mass, body composition, metabolic rate, and plasma leptin and IGF-I levels. Eight female pigs were included in the study. Under general anesthesia, a bipolar electrode was implanted on the anterior vagal nerve by laparoscopy. Group A was treated by VNS, and group B was the control. After 4 weeks, stimulation was discontinued in group A and started in group B. The following parameters were evaluated: body mass, body composition, metabolic rate, plasma leptin and IGF-1 levels and intramuscular fat content (IMF). VNS attenuated body weight gain (2.28 +/- 3.47 kg vs 14.04 +/- 6.75 kg; P = .0112, for stimulation and nonstimulation periods, respectively), backfat gain (0.04 +/- 0.26 mm vs 2.31 +/- 1.12 mm) and IMF gain (-3.76 +/- 6.06 mg/g MS vs 7.24 +/- 12.90 mg/g MS; P = .0281). VNS resulted in lower backfat depth/loin muscle area ratio (0.33 +/- 0.017 vs 0.38 +/- 0.35; P = .0476). Lower plasma IGF-I concentration was found after VNS (-3.67 +/- -11.55 ng/mL vs 9.86 +/- 10.74 ng/mL; P = .0312). No significant changes in other parameters were observed. VNS affects body weight mainly at the expense of body fat resources; however, metabolic rate is not affected.

Resting and postexercise heart rate variability in professional handball players.

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Kayacan, Yildirim; Yildiz, Sedat

2016-03-01

The aim of this study was to evaluate heart rate variability (HRV) in professional handball players during rest and following a 5 min mild jogging exercise. For that purpose, electrocardiogram (ECG) of male handball players (N.=12, mean age 25±3.95 years) and sedentary controls (N.=14, mean age 23.5±2.95 years) were recorded for 5 min at rest and just after 5 min of mild jogging. ECGs were recorded and following HRV parameters were calculated: time-domain variables such as heart rate (HR), average normal-to-normal RR intervals, standard deviation of normal-to-normal RR intervals, square root of the mean of the squares of differences between adjacent NN intervals, percentage of differences between adjacent NN intervals that are greater than 50 milliseconds (pNN50), and frequency-domain variables such as very low frequency, low (LF) and high frequency (HF) of the power and LF/HF ratio. Unpaired t-test was used to find out differences among groups while paired t-test was used for comparison of each group for pre- and postjogging HRV. Pearson correlations were carried out to find out the relationships between the parameters. Blood pressures were not different between handball players and sedentary controls but exercise increased systolic blood pressure (Phandball players (Phandball players (Phandball players in response to a mild, short-time (5 min) jogging exercise. However, in sedentary subjects, either the sympathetic regulation of the autonomous nervous system increased or vagal withdrawal occurred.

Heart rate variability during acute psychosocial stress: A randomized cross-over trial of verbal and non-verbal laboratory stressors.

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Brugnera, Agostino; Zarbo, Cristina; Tarvainen, Mika P; Marchettini, Paolo; Adorni, Roberta; Compare, Angelo

2018-05-01

Acute psychosocial stress is typically investigated in laboratory settings using protocols with distinctive characteristics. For example, some tasks involve the action of speaking, which seems to alter Heart Rate Variability (HRV) through acute changes in respiration patterns. However, it is still unknown which task induces the strongest subjective and autonomic stress response. The present cross-over randomized trial sought to investigate the differences in perceived stress and in linear and non-linear analyses of HRV between three different verbal (Speech and Stroop) and non-verbal (Montreal Imaging Stress Task; MIST) stress tasks, in a sample of 60 healthy adults (51.7% females; mean age = 25.6 ± 3.83 years). Analyses were run controlling for respiration rates. Participants reported similar levels of perceived stress across the three tasks. However, MIST induced a stronger cardiovascular response than Speech and Stroop tasks, even after controlling for respiration rates. Finally, women reported higher levels of perceived stress and lower HRV both at rest and in response to acute psychosocial stressors, compared to men. Taken together, our results suggest the presence of gender-related differences during psychophysiological experiments on stress. They also suggest that verbal activity masked the vagal withdrawal through altered respiration patterns imposed by speaking. Therefore, our findings support the use of highly-standardized math task, such as MIST, as a valid and reliable alternative to verbal protocols during laboratory studies on stress. Copyright © 2018 Elsevier B.V. All rights reserved.

TRPA1 mediates changes in heart rate variability and cardiac mechanical function in mice exposed to acrolein

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Kurhanewicz, Nicole [Curriculum in Toxicology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599 (United States); McIntosh-Kastrinsky, Rachel [Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599 (United States); Tong, Haiyan; Ledbetter, Allen; Walsh, Leon; Farraj, Aimen [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Hazari, Mehdi, E-mail: hazari.mehdi@epa.gov [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States)

2017-06-01

Short-term exposure to ambient air pollution is linked with adverse cardiovascular effects. While previous research focused primarily on particulate matter-induced responses, gaseous air pollutants also contribute to cause short-term cardiovascular effects. Mechanisms underlying such effects have not been adequately described, however the immediate nature of the response suggests involvement of irritant neural activation and downstream autonomic dysfunction. Thus, this study examines the role of TRPA1, an irritant sensory receptor found in the airways, in the cardiac response of mice to acrolein and ozone. Conscious unrestrained wild-type C57BL/6 (WT) and TRPA1 knockout (KO) mice implanted with radiotelemeters were exposed once to 3 ppm acrolein, 0.3 ppm ozone, or filtered air. Heart rate (HR) and electrocardiogram (ECG) were recorded continuously before, during and after exposure. Analysis of ECG morphology, incidence of arrhythmia and heart rate variability (HRV) were performed. Cardiac mechanical function was assessed using a Langendorff perfusion preparation 24 h post-exposure. Acrolein exposure increased HRV independent of HR, as well as incidence of arrhythmia. Acrolein also increased left ventricular developed pressure in WT mice at 24 h post-exposure. Ozone did not produce any changes in cardiac function. Neither gas produced ECG effects, changes in HRV, arrhythmogenesis, or mechanical function in KO mice. These data demonstrate that a single exposure to acrolein causes cardiac dysfunction through TRPA1 activation and autonomic imbalance characterized by a shift toward parasympathetic modulation. Furthermore, it is clear from the lack of ozone effects that although gaseous irritants are capable of eliciting immediate cardiac changes, gas concentration and properties play important roles. - Highlights: • Acute acrolein exposure causes autonomic imbalance and altered CV function in mice. • TRPA1 mediates acrolein-induced autonomic nervous system cardiac

TRPA1 mediates changes in heart rate variability and cardiac mechanical function in mice exposed to acrolein

International Nuclear Information System (INIS)

Kurhanewicz, Nicole; McIntosh-Kastrinsky, Rachel; Tong, Haiyan; Ledbetter, Allen; Walsh, Leon; Farraj, Aimen; Hazari, Mehdi

2017-01-01

Short-term exposure to ambient air pollution is linked with adverse cardiovascular effects. While previous research focused primarily on particulate matter-induced responses, gaseous air pollutants also contribute to cause short-term cardiovascular effects. Mechanisms underlying such effects have not been adequately described, however the immediate nature of the response suggests involvement of irritant neural activation and downstream autonomic dysfunction. Thus, this study examines the role of TRPA1, an irritant sensory receptor found in the airways, in the cardiac response of mice to acrolein and ozone. Conscious unrestrained wild-type C57BL/6 (WT) and TRPA1 knockout (KO) mice implanted with radiotelemeters were exposed once to 3 ppm acrolein, 0.3 ppm ozone, or filtered air. Heart rate (HR) and electrocardiogram (ECG) were recorded continuously before, during and after exposure. Analysis of ECG morphology, incidence of arrhythmia and heart rate variability (HRV) were performed. Cardiac mechanical function was assessed using a Langendorff perfusion preparation 24 h post-exposure. Acrolein exposure increased HRV independent of HR, as well as incidence of arrhythmia. Acrolein also increased left ventricular developed pressure in WT mice at 24 h post-exposure. Ozone did not produce any changes in cardiac function. Neither gas produced ECG effects, changes in HRV, arrhythmogenesis, or mechanical function in KO mice. These data demonstrate that a single exposure to acrolein causes cardiac dysfunction through TRPA1 activation and autonomic imbalance characterized by a shift toward parasympathetic modulation. Furthermore, it is clear from the lack of ozone effects that although gaseous irritants are capable of eliciting immediate cardiac changes, gas concentration and properties play important roles. - Highlights: • Acute acrolein exposure causes autonomic imbalance and altered CV function in mice. • TRPA1 mediates acrolein-induced autonomic nervous system cardiac

Direct projections from hypothalamic orexin neurons to brainstem cardiac vagal neurons.

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Dergacheva, Olga; Yamanaka, Akihiro; Schwartz, Alan R; Polotsky, Vsevolod Y; Mendelowitz, David

2016-12-17

Orexin neurons are known to augment the sympathetic control of cardiovascular function, however the role of orexin neurons in parasympathetic cardiac regulation remains unclear. To test the hypothesis that orexin neurons contribute to parasympathetic control we selectively expressed channelrhodopsin-2 (ChR2) in orexin neurons in orexin-Cre transgenic rats and examined postsynaptic currents in cardiac vagal neurons (CVNs) in the dorsal motor nucleus of the vagus (DMV). Simultaneous photostimulation and recording in ChR2-expressing orexin neurons in the lateral hypothalamus resulted in reliable action potential firing as well as large whole-cell currents suggesting a strong expression of ChR2 and reliable optogenetic excitation. Photostimulation of ChR2-expressing fibers in the DMV elicited short-latency (ranging from 3.2ms to 8.5ms) postsynaptic currents in 16 out of 44 CVNs tested. These responses were heterogeneous and included excitatory glutamatergic (63%) and inhibitory GABAergic (37%) postsynaptic currents. The results from this study suggest different sub-population of orexin neurons may exert diverse influences on brainstem CVNs and therefore may play distinct functional roles in parasympathetic control of the heart. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Heart rate variability and pre-competitive anxiety in BMX discipline.

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Mateo, Manuel; Blasco-Lafarga, Cristina; Martínez-Navarro, Ignacio; Guzmán, José F; Zabala, Mikel

2012-01-01

Altered neural mechanisms implying autonomic functioning have been described related to anxiety. Pre-competitive stress may be considered as an anxiety-state associated with disorders (i.e. somatic and cognitive alterations, and self-confidence worsening) that severely impair sport performance, conditioning short-lasting strength-related disciplines like BMX. From the psychological perspective, coaches use questionnaires like CSAI-2R to identify these alterations. However, with the emergence of psycho-physiological and non-linear approaches, recent studies suggest that HRV analysis provides a non-invasive tool to assess them. Hence, our purpose was to analyze how BMX competition affects subjective perception of anxiety, and if this emotional alteration is reflected in HR dynamics, analyzed both linear and nonlinearly, exploring the evolution of this relationship in a 2-day competition. Eleven male athletes from the BMX Spanish National Team were assessed from baseline HRV the morning of a training session (rT) and on two successive days of competition (rC1 and rC2), repeating HRV recording with CSAI-2R 20 min prior to training (aT) and competition (pre-competitive: aC1 and aC2). Repeated measures MANOVA showed significant vagal slow-down responses in aC1 and aC2 comparing not only with aT, but also comparing with rT, rC1 and rC2, coinciding with significant greater scores for the somatic and cognitive anxiety (SA and CA) in aC1 and aC2 versus aT. Pearson analysis showed a large and positive correlation between α1 and SA in C1, and close to it between SampEn and CA in aC2; both were confirmed by Bland-Altman chart analysis. Our results confirm that HRV analysis provide a complementary tool to assess competitive pressure.

Spectral analysis of cardiac rate variability Análisis espectral de la variabilidad de la frecuencia cardíaca

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Diego Luis Alvarez Montoya

1999-02-01

Full Text Available In the last years relationship between autonomic nervous system (ANS function and cardiovascular mortality has been recognized. This has motivated research to find quantitative markers of autonomic balance. Heart rate variability (HRV is one of the most promising methods. HRV is defined as the variations occurred in the time interval between consecutive heartbeats and it is thought to depend on the ANS modulation. Tacogram (recording of cardiac frequency in time is used to evaluate HRV. The study of HRV started 30 years ago and has gained importance in the last 10 years. There are several methods to evaluate HRV. The most accepted today are frequency domain methods (spectral analysis. Spectral analysis consists in the decomposition in order to obtain the spectral components. There are high frequency components (HF, related to vagal tone, low frequency (LF components, related to the modulation of both sympathetic and vagal modulation, and very low frequency components which have not been related to any physiological variable. Time domain methods, are basically statistic and evaluate variability using means and standard deviations. These methods seem to have less advantages than spectral methods. HRV is correlated with physiological adaptations to changes in internal and external environment and to the presence of diseases. This article presents the main techniques in the time and frequency domains and their relationship with physiological changes and specific diseases. En los últimos años, se ha reconocido la relación existente entre el funcionamiento del sistema nervioso autónomo (SNA y la mortalidad cardiovascular. Esto ha motivado la búsqueda de marcadores cuantitativos del balance autonómico. La Variabilidad de la Frecuencia Cardíaca (VFC representa uno de los más promisorios. La VFC se define como la variación que ocurre en el intervalo de tiempo entre latidos consecutivos y se ha propuesto que su comportamiento depende de la

Vagal Blocking Improves Glycemic Control and Elevated Blood Pressure in Obese Subjects with Type 2 Diabetes Mellitus

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S. Shikora

2013-01-01

Full Text Available Background. An active device that downregulates abdominal vagal signalling has resulted in significant weight loss in feasibility studies. Objective. To prospectively evaluate the effect of intermittent vagal blocking (VBLOC on weight loss, glycemic control, and blood pressure (BP in obese subjects with DM2. Methods. Twenty-eight subjects were implanted with a VBLOC device (Maestro Rechargeable System at 5 centers in an open-label study. Effects on weight loss, HbA1c, fasting blood glucose, and BP were evaluated at 1 week to 12 months. Results. 26 subjects (17 females/9 males, 51±2 years, BMI 37±1 kg/m2, mean ± SEM completed 12 months followup. One serious adverse event (pain at implant site was easily resolved. At 1 week and 12 months, mean excess weight loss percentages (% EWL were 9±1% and 25±4% (P<0.0001, and HbA1c declined by 0.3±0.1% and 1.0±0.2% (P=0.02, baseline 7.8±0.2%. In DM2 subjects with elevated BP (n=15, mean arterial pressure reduced by 7±3 mmHg and 8±3 mmHg (P=0.04, baseline 100 ± 2 mmHg at 1 week and 12 months. All subjects MAP decreased by 3 ± 2 mmHg (baseline 95 ± 2 mmHg at 12 months. Conclusions. VBLOC was safe in obese DM2 subjects and associated with meaningful weight loss, early and sustained improvements in HbA1c, and reductions in BP in hypertensive DM2 subjects. This trial is registered with ClinicalTrials.gov NCT00555958.

The serotonin receptor mediates changes in autonomic neurotransmission and gastrointestinal transit induced by heat-killed Lactobacillus brevis SBC8803.

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Horii, Y; Nakakita, Y; Misonou, Y; Nakamura, T; Nagai, K

2015-01-01

Lactobacilli exhibit several health benefits in mammals, including humans. Our previous reports established that heat-killed Lactobacillus brevis SBC8803 (SBC8803) increased both efferent gastric vagal nerve activity and afferent intestinal vagal nerve activity in rats. We speculated that this strain could be useful for the treatment of gastrointestinal (GI) disorders. In this study, we examined the effects of SBC8803 on peristalsis and the activity of the efferent celiac vagal nerve innervating the intestine in rats. First, we examined the effects of intraduodenal (ID) administration of SBC8803 on efferent celiac vagal nerve activity (efferent CVNA) in urethane-anesthetised rats using electrophysiological studies. The effects of intravenous injection of the serotonin 5-HT3 receptor antagonist granisetron on changes in efferent CVNA due to ID administration of SBC8803 were also investigated. Finally, the effects of oral gavage of SBC8803 on GI transit were analysed using the charcoal propulsion method in conscious rats treated with or without granisetron. ID administration of SBC8803 increased efferent CVNA. Pretreatment with granisetron eliminated SBC8803-dependent changes in efferent CVNA. Furthermore, oral gavage of SBC8803 significantly accelerated GI transit, while pretreatment with granisetron inhibited GI transit. Our findings suggested that SBC8803 increased efferent CVNA and GI transit of charcoal meal via 5-HT3 receptors. Moreover, SBC8803 enhanced the activity of efferent vagal nerve innervating the intestine and promoted peristalsis via 5-HT3 receptors.

The 2 Hz and 15 Hz electroacupuncture induced reverse effect on autonomic function in healthy adult using a heart rate variability analysis

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Bor-An Jia

2011-10-01

Full Text Available The purpose of the present study was to investigate effect of electro-acupuncture (EA at different frequencies on autonomic function. Twenty healthy adult volunteers were studied, and underwent 4 sessions of EA (sham, 2 Hz, 15 Hz, and 50 Hz. Sham, 2 Hz, 15 Hz, and 50 Hz EA was applied to the bilateral Leg Three Li (足三里 zú sān lǐ, ST-36 and Upper Great Hollow (上巨虛 shàng jù xū, ST-37 acupoints. The intensity of electrical stimulation was adjusted to obtain visible twitching of the anterior tibial muscle about 2.0-2.5 mA except sham without electrical stimulation. The components of heart rate variability (HRV and blood pressure were measured before EA (BLP, EA (EAP, and post-EA periods (PEP. The results indicated that the natural logarithmic high frequency power (lnHF of HRV was greater during PEP than during the BLP in the 2 Hz EA sessions. The natural logarithmic low frequency power (lnLF of HRV was greater during the PEP than during the BLP in 15 Hz EA sessions, suggesting that 2 Hz EA apply to Leg Three Li (足三里 zú sān lǐ, ST-36 and Upper Great Hollow (上巨虛 shàng jù xū, ST-37 acupoints increased vagal activity, whereas 15 Hz EA increased sympathetic activity.

Autonomic nervous system activation mediates the increase in whole-body glucose uptake in response to electroacupuncture

DEFF Research Database (Denmark)

Benrick, Anna; Kokosar, Milana; Hu, Min

2017-01-01

was higher after EA in controls and women with PCOS. Plasma serotonin levels and homovanillic acid, markers of vagal activity, decreased in both controls and patients with PCOS. Adipose tissue expression of pro-nerve growth factor (proNGF) decreased, and the mature NGF/proNGF ratio increased after EA in PCOS...... of EA increases whole-body glucose uptake by activation of the sympathetic and partly the parasympathetic nervous systems, which could have important clinical implications for the treatment of insulin resistance.-Benrick, A., Kokosar, M., Hu, M., Larsson, M., Maliqueo, M., Marcondes, R. R., Soligo, M......., Protto, V., Jerlhag, E., Sazonova, A., Behre, C. J., Højlund, K., Thorén, P., Stener-Victorin, E. Autonomic nervous system activation mediates the increase in whole-body glucose uptake in response to electroacupuncture....

Urban air pollution targets the dorsal vagal complex and dark chocolate offers neuroprotection.

Science.gov (United States)

Villarreal-Calderon, Rafael; Torres-Jardón, Ricardo; Palacios-Moreno, Juan; Osnaya, Norma; Pérez-Guillé, Beatriz; Maronpot, Robert R; Reed, William; Zhu, Hongtu; Calderón-Garcidueñas, Lilian

2010-12-01

Mexico City (MC) residents exposed to fine particulate matter and endotoxin exhibit inflammation of the olfactory bulb, substantia nigra, and vagus nerve. The goal of this study was to model these endpoints in mice and examine the neuroprotective effects of chocolate. Mice exposed to MC air received no treatment or oral dark chocolate and were compared to clean-air mice either untreated or treated intraperitoneally with endotoxin. Cyclooxygenase-2 (COX-2), interleukin 1 beta (IL-1β), and CD14 messenger RNA (mRNA) were quantified after 4, 8, and 16 months of exposure in target brain regions. After 16 months of exposure, the dorsal vagal complex (DVC) exhibited significant inflammation in endotoxin-treated and MC mice (COX-2 and IL-1β P<.001). Mexico City mice had olfactory bulb upregulation of CD14 (P=.002) and significant DVC imbalance in genes for antioxidant defenses, apoptosis, and neurodegeneration. These findings demonstrate sustained DVC inflammation in mice exposed to MC air, which is mitigated by chocolate administration. © The Author(s) 2010

Dexamethasone rapidly increases GABA release in the dorsal motor nucleus of the vagus via retrograde messenger-mediated enhancement of TRPV1 activity.

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Andrei V Derbenev

Full Text Available Glucocorticoids influence vagal parasympathetic output to the viscera via mechanisms that include modulation of neural circuitry in the dorsal vagal complex, a principal autonomic regulatory center. Glucocorticoids can modulate synaptic neurotransmitter release elsewhere in the brain by inducing release of retrograde signalling molecules. We tested the hypothesis that the glucocorticoid agonist dexamethasone (DEX modulates GABA release in the rat dorsal motor nucleus of the vagus (DMV. Whole-cell patch-clamp recordings revealed that DEX (1-10 µM rapidly (i.e. within three minutes increased the frequency of tetrodotoxin-resistant, miniature IPSCs (mIPSCs in 67% of DMV neurons recorded in acutely prepared slices. Glutamate-mediated mEPSCs were also enhanced by DEX (10 µM, and blockade of ionotropic glutamate receptors reduced the DEX effect on mIPSC frequency. Antagonists of type I or II corticosteroid receptors blocked the effect of DEX on mIPSCs. The effect was mimicked by application of the membrane-impermeant BSA-conjugated DEX, and intracellular blockade of G protein function with GDP βS in the recorded cell prevented the effect of DEX. The enhancement of GABA release was blocked by the TRPV1 antagonists, 5'-iodoresiniferatoxin or capsazepine, but was not altered by the cannabinoid type 1 receptor antagonist AM251. The DEX effect was prevented by blocking fatty acid amide hydrolysis or by inhibiting anandamide transport, implicating involvement of the endocannabinoid system in the response. These findings indicate that DEX induces an enhancement of GABA release in the DMV, which is mediated by activation of TRPV1 receptors on afferent terminals. The effect is likely induced by anandamide or other 'endovanilloid', suggesting activation of a local retrograde signal originating from DMV neurons to enhance synaptic inhibition locally in response to glucocorticoids.

Response of Blood Perfusion at ST 36 Acupoint after Drinking Cold Glucose or Saline Injection

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Guangjun Wang

2017-01-01

Full Text Available Skin blood flux (SkBF changes caused by drinking cold water are generally associated with vagal tone and osmotic factors in digestive system. According to acupuncture theory, change of SkBF at ST 36 might reflect the functional changes of digestive system. The aim of this study is to analyze the changes of SkBF after drinking 3°C 0.9% saline or 5% glucose injection by monitor blood flux at bilateral ST 36. The results indicated that, after drinking different cold water, the change ratio of SkBF at right side ST 36 has been different. Because all solutions have the same temperature (3°C and both saline and glucose solution have the same osmolality, suggesting that the SkBF changes resulting from drinking cold water are not regulated just by the vagal tone and osmolality, there must have been other factors. These results have not been consistent with the frequency domain results of heart rate variability (HRV analysis. Coherence analysis of blood flux signals at bilateral ST 36 indicated that there have been different coherence-frequency curves among different groups in special frequency bands, which suggested that coherence analysis might provide a potential tool to evaluate different status.

Symbolic dynamics of heart rate variability - a promising tool to investigate cardiac sympathovagal control in attention deficit/hyperactivity disorder (ADHD)?

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Tonhajzerova, Ingrid; Farsky, Ivan; Mestanik, Michal; Visnovcova, Zuzana; Mestanikova, Andrea; Hrtanek, Igor; Ondrejka, Igor

2016-06-01

We aimed to evaluate complex cardiac sympathovagal control in attention deficit/hyperactivity disorder (ADHD) by using heart rate variability (HRV) nonlinear analysis - symbolic dynamics. We examined 29 boys with untreated ADHD and 25 healthy boys (age 8-13 years). ADHD symptoms were evaluated by ADHD-RS-IV scale. ECG was recorded in 3 positions: baseline supine position, orthostasis, and clinostasis. Symbolic dynamics indices were used for the assessment of complex cardiac sympathovagal regulation: normalised complexity index (NCI), normalised unpredictability index (NUPI), and pattern classification measures (0V%, 1V%, 2LV%, 2UV%). The results showed that HRV complexity was significantly reduced at rest (NUPI) and during standing position (NCI, NUPI) in ADHD group compared to controls. Cardiac-linked sympathetic index 0V% was significantly higher during all posture positions and cardiovagal index 2LV% was significantly lower to standing in boys suffering from ADHD. Importantly, ADHD symptom inattention positively correlated with 0V%, and negatively correlated with NCI, NUPI. Concluding, symbolic dynamics revealed impaired complex neurocardiac control characterised by potential cardiac beta-adrenergic overactivity and vagal deficiency at rest and to posture changes in boys suffering from ADHD that is correlated with inattention. We suggest that symbolic dynamics indices could represent promising cardiac biomarkers in ADHD.

AUTONOMIC CONTROL OF HEART RATE AFTER EXERCISE IN TRAINED WRESTLERS

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Carlos F Henríquez

2013-04-01

Full Text Available The objective of this study was to establish differences in vagal reactivation, through heart rate recovery and heart rate variability post exercise, in Brazilian jiu-jitsu wrestlers (BJJW. A total of 18 male athletes were evaluated, ten highly trained (HT and eight moderately trained (MT, who performed a maximum incremental test. At the end of the exercise, the R-R intervals were recorded during the first minute of recovery. We calculated heart rate recovery (HRR60s, and performed linear and non-linear (standard deviation of instantaneous beat-to-beat R-R interval variability – SD1 analysis of heart rate variability (HRV, using the tachogram of the first minute of recovery divided into four segments of 15 s each (0-15 s, 15-30 s, 30-45 s, 45-60 s. Between HT and MT individuals, there were statistically significant differences in HRR60s (p <0.05 and in the non linear analysis of HRV from SD130-45s (p <0.05 and SD145-60s (p <0.05. The results of this research suggest that heart rate kinetics during the first minute after exercise are related to training level and can be used as an index for autonomic cardiovascular control in BJJW.

Increased heart rate variability in mice overexpressing the Cu/Zn superoxide dismutase.

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Thireau, Jérôme; Poisson, Denise; Zhang, Bei Li; Gillet, Ludovic; Le Pécheur, Marie; Andres, Christian; London, Jacqueline; Babuty, Dominique

2008-08-15

Cu/Zn superoxide dismutase (SOD1) is implicated in various pathological conditions including Down's syndrome, neurodegenerative diseases, and afflictions of the autonomic nervous system (ANS). To assess the SOD1 contribution to ANS dysfunction, especially its influence on cardiac regulation, we studied the heart rate variability (HRV) and cardiac arrhythmias in conscious 12-month-old male and female transgenic mice for the human SOD1 gene (TghSOD1). TghSOD1 mice presented heart rate reduction as compared with control FVB/N individuals. All HRV parameters reflecting parasympathetic activity were increased in TghSOD1. Pharmacological studies confirmed that the parasympathetic tone was exacerbated and the sympathetic pathway was functional in TghSOD1 mice. A high frequency of atrioventricular block and premature ventricular contractions was observed in TghSOD1. By biochemical assays we found that SOD1 activities were multiplied by 9 and 4 respectively in the heart and brainstem of transgenic mice. A twofold decrease in cholinesterase activity was observed in the heart but not in the brainstem. We demonstrate that SOD1 overexpression induces an ANS dysfunction by an exacerbated vagal tone that may be related to impaired cardiac activity of the cholinesterases and may explain the high occurrence of arrhythmias.

Immunocytochemical localization of glutamic acid decarboxylase (GAD) and substance P in neural areas mediating motion-induced emesis: Effects of vagal stimulation on GAD immunoreactivity

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Damelio, F.; Gibbs, M. A.; Mehler, W. R.; Daunton, Nancy G.; Fox, Robert A.

1991-01-01

Immunocytochemical methods were employed to localize the neurotransmitter amino acid gamma-aminobutyric acid (GABA) by means of its biosynthetic enzyme glutamic acid decarboxylase (GAD) and the neuropeptide substance P in the area postrema (AP), area subpostrema (ASP), nucleus of the tractus solitarius (NTS), and gelatinous nucleus (GEL). In addition, electrical stimulation was applied to the night vagus nerve at the cervical level to assess the effects on GAD-immunoreactivity (GAR-IR). GAD-IR terminals and fibers were observed in the AP, ASP, NTS, and GEL. They showed pronounced density at the level of the ASP and gradual decrease towards the solitary complex. Nerve cells were not labelled in our preparations. Ultrastructural studies showed symmetric or asymmetric synaptic contracts between labelled terminals and non-immunoreactive dendrites, axons, or neurons. Some of the labelled terminals contained both clear- and dense-core vesicles. Our preliminary findings, after electrical stimulation of the vagus nerve, revealed a bilateral decrease of GAD-IR that was particularly evident at the level of the ASP. SP-immunoreactive (SP-IR) terminals and fibers showed varying densities in the AP, ASP, NTS, and GEL. In our preparations, the lateral sub-division of the NTS showed the greatest accumulation. The ASP showed medium density of immunoreactive varicosities and terminals and the AP and GEL displayed scattered varicose axon terminals. The electron microscopy revealed that all immunoreactive terminals contained clear-core vesicles which make symmetric or asymmetric synaptic contact with unlabelled dendrites. It is suggested that the GABAergic terminals might correspond to vagal afferent projections and that GAD/GABA and substance P might be co-localized in the same terminal allowing the possibility of a regulated release of the transmitters in relation to demands.

The effect of orexin-A on cardiac dysfunction mediated by NADPH oxidase-derived superoxide anion in ventrolateral medulla.

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Jun Chen

Full Text Available Hypocretin/orexin-producing neurons, located in the perifornical region of the lateral hypothalamus area (LHA and projecting to the brain sites of rostral ventrolateral medulla (RVLM, involve in the increase of sympathetic activity, thereby regulating cardiovascular function. The current study was designed to test the hypothesis that the central orexin-A (OXA could be involved in the cardiovascular dysfunction of acute myocardial infarction (AMI by releasing NAD(PH oxidase-derived superoxide anion (O2 (- generation in RVLM, AMI rat model established by ligating the left anterior descending (LAD coronary artery to induce manifestation of cardiac dysfunction, monitored by the indicators as heart rate (HR, heart rate variability (HRV, mean arterial pressure (MAP and left intraventricular pressure. The results showed that the expressions of OXA in LHA and orexin 1 receptor (OX1R increased in RVLM of AMI rats. The double immunofluorescent staining indicated that OX1R positive cells and NAD(PH oxidative subunit gp91phox or p47phox-immunoreactive (IR cells were co-localized in RVLM. Microinjection of OXA into the cerebral ventricle significantly increased O2 (- production and mRNA expression of NAD(PH oxidase subunits when compared with aCSF-treated ones. Exogenous OXA administration in RVLM produced pressor and tachycardiac effects. Furthermore, the antagonist of OX1R and OX2R (SB-408124 and TCS OX2 29, respectively or apocynin (APO, an inhibitor of NAD(PH oxidase, partly abolished those cardiovascular responses of OXA. HRV power spectral analysis showed that exogenous OXA led to decreased HF component of HRV and increased LF/HF ratio in comparison with aCSF, which suggested that OXA might be related to sympathovagal imbalance. As indicated by the results, OXA might participate in the central regulation of cardiovascular activities by disturbing the sympathovagal balance in AMI, which could be explained by the possibility that OXR and NAD(PH-derived O

Heart rate variability alters cardiac repolarization and electromechanical dynamics.

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Phadumdeo, Vrishti M; Weinberg, Seth H

2018-04-07

Heart rate continuously varies due to autonomic regulation, stochasticity in pacemaking, and circadian rhythm, collectively termed heart rate variability (HRV), during normal physiological conditions. Low HRV is clinically associated with an elevated risk of cardiac arrhythmias. Alternans, a beat-to-beat alternation in action potential duration (APD) and/or intracellular calcium (Ca) transient, is a well-known risk factor associated with cardiac arrhythmias that is typically studied under conditions of a constant pacing rate, i.e., the absence of HRV. In this study, we investigate the effects of HRV on the interplay between APD, Ca, and electromechanical properties, employing a nonlinear discrete-time map model that governs APD and intracellular Ca cycling with a stochastic pacing period. We find that HRV can decrease variation in APD and peak Ca at fast pacing rates for which alternans is present. Further, increased HRV typically disrupts the alternating pattern for both APD and peak Ca and weakens the correlation between APD and peak Ca, thus decoupling Ca-mediated instabilities from repolarization alternation. We find that the efficacy of these effects is regulated by the sarcoplasmic reticulum Ca uptake rate. Overall, these results demonstrate that HRV disrupts arrhythmogenic alternans and suggests that HRV may be a significant factor in preventing life-threatening arrhythmias. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of Exercise Testing on Short-term Heart Rate Variability in Patients with Coronary Heart Disease

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Niu, Hui-Yan; Zhang, Dai-Fu; Liang, Bo

2005-01-01

nervous system remains balanced in patients with CHD in stationary supine position without myocardiac ischemia; (2) Vagal tone withdraws during the exercise time and increases during the recovery period; (3) The changes of HRV in patients with CHD present ischemia-induced reflective sympathetic activity...... was shown in the second 5-minute frequency domain analysis (LFnorm, HFnorm and LF/HF) after ET(P0.05); (3) In the whole course of ET,the frequency domain analysis showed that LF and LFnorm were higher and HF,HFnorm were lower in CHD than those in controls.Conclusion It is concluded that (1) Sympathovagal...... predominance during the recovery period; (4) The autonomic nervous system in CHD is disordered during ET. This results suggest that ET is helpful in detecting the disorder of sympathovagal nervous system in patients with CHD....

Affective and physiological responses to the suffering of others: compassion and vagal activity.

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Stellar, Jennifer E; Cohen, Adam; Oveis, Christopher; Keltner, Dacher

2015-04-01

Compassion is an affective response to another's suffering and a catalyst of prosocial behavior. In the present studies, we explore the peripheral physiological changes associated with the experience of compassion. Guided by long-standing theoretical claims, we propose that compassion is associated with activation in the parasympathetic autonomic nervous system through the vagus nerve. Across 4 studies, participants witnessed others suffer while we recorded physiological measures, including heart rate, respiration, skin conductance, and a measure of vagal activity called respiratory sinus arrhythmia (RSA). Participants exhibited greater RSA during the compassion induction compared with a neutral control (Study 1), another positive emotion (Study 2), and a prosocial emotion lacking appraisals of another person's suffering (Study 3). Greater RSA during the experience of compassion compared with the neutral or control emotion was often accompanied by lower heart rate and respiration but no difference in skin conductance. In Study 4, increases in RSA during compassion positively predicted an established composite of compassion-related words, continuous self-reports of compassion, and nonverbal displays of compassion. Compassion, a core affective component of empathy and prosociality, is associated with heightened parasympathetic activity. (c) 2015 APA, all rights reserved).

Heart rate variability (HRV) and muscular system activity (EMG) in cases of crash threat during simulated driving of a passenger car.

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Zużewicz, Krystyna; Roman-Liu, Danuta; Konarska, Maria; Bartuzi, Paweł; Matusiak, Krzysztof; Korczak, Dariusz; Lozia, Zbigniew; Guzek, Marek

2013-10-01

The aim of the study was to verify whether simultaneous responses from the muscular and circulatory system occur in the driver's body under simulated conditions of a crash threat. The study was carried out in a passenger car driving simulator. The crash was included in the driving test scenario developed in an urban setting. In the group of 22 young male subjects, two physiological signals - ECG and EMG were continuously recorded. The length of the RR interval in the ECG signal was assessed. A HRV analysis was performed in the time and frequency domains for 1-minute record segments at rest (seated position), during undisturbed driving as well as during and several minutes after the crash. For the left and right side muscles: m. trapezius (TR) and m. flexor digitorum superficialis (FDS), the EMG signal amplitude was determined. The percentage of maximal voluntary contraction (MVC) was compared during driving and during the crash. As for the ECG signal, it was found that in most of the drivers changes occurred in the parameter values reflecting HRV in the time domain. Significant changes were noted in the mean length of RR intervals (mRR). As for the EMG signal, the changes in the amplitude concerned the signal recorded from the FDS muscle. The changes in ECG and EMG were simultaneous in half of the cases. Such parameters as mRR (ECG signal) and FDS-L amplitude (EMG signal) were the responses to accident risk. Under simulated conditions, responses from the circulatory and musculoskeletal systems are not always simultaneous. The results indicate that a more complete driver's response to a crash in road traffic is obtained based on parallel recording of two physiological signals (ECG and EMG).

Positional differences in the cardiorespiratory, autonomic, and somatic profiles of professional soccer players

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Martin Semjon

2016-06-01

Full Text Available Background: In order to optimize training in soccer, knowledge about the specific position fitness demands and characteristics is required. Objective: The aim of the study was to determine whether there are position specific differences in somatic, cardiorespiratory and autonomic cardiac profiles of professional senior Czech soccer players. Methods: All players (N = 120 were divided into six groups according to field positions: goalkeeper (GK; n = 11, external defenders (ED; n = 15, central defenders (CD; n = 18, external midfielders (EM; n = 18, central midfielders (CM; n = 24 and forwards (F; n = 34. Players underwent anthropometrical and heart rate variability (HRV assessment, and a maximal incremental running test in order to obtain maximal oxygen uptake (VO2max and heart rate. HRV variables were transformed using the natural logarithm (Ln. Results: GK and CD were significantly (p = .005 heavier than ED, EM, CM, and F; while F were significantly (p = .026 heavier than CM and EM. GK and CD were significantly (p = .008 taller than ED, EM, CM, F; and EM were significantly (p = .041 shorter than CM and F. The only significant (p = .043 difference in percentage of body fat was observed in CD compared with CM. A significantly (p = .021 lower VO2max was observed for GK compared with ED, CD, EM, CM, and F. Supine HRV was significantly (p = .039 lower for Ln LF/HF in GK compared with F. Standing HRV was significantly (p = .03 lower for Ln LF in CD compared with both ED and F, significantly (p = .028 higher for Ln LF/HF in ED compared with CD and EM. Conclusions: In soccer, specific positions are associated with different height, body mass and aerobic capacity. A lower VO2max and vagal activity in GK compared with other playing positions may not be considered as disadvantage for performance in this specific playing position.

Autonomic cardiac regulation and morpho-physiological responses to eight week training preparation in junior soccer players

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Michal Botek

2014-09-01

Full Text Available Background: Training preparation in soccer is thought to improve body composition and performance level, especially the maximal aerobic capacity (VO2max. However, an enhancement in performance may be attenuated by the increase of fatigue. Heart rate variability (HRV as a non-invasive index of autonomic nervous system (ANS activity has been considered to be a sensitive tool in fatigue assessment. Objective: This study was focused to evaluate the response of ANS activity and morpho-physiological parameters to eight week training preparation. Methods: Study included 12 trained soccer players aged 17.2 ± 1.2 years. Athletes underwent pre- and post-preparation testing that included the ANS activity assessment by spectral analysis of HRV in supine and upright position. Further, body composition was analyzed via electrical bio-impedance method and physiological parameters were assessed during maximal stress tests. ANS activity and subjective feeling of fatigue was assessed continuously within subsequent weeks of preparation. Results: No significant differences in all HRV variables within weeks were found. Pre vs. post analyses revealed a significant (p < .05 increase in body weight, fat free mass, body mass index, and peak power. A significant decline in mean maximal heart rate (HR and resting HR at standing was identified at the end of preparation. Since no significant changes between pre- post-preparation in the mean VO2max occurred, the positive correlation between the individual change in VO2max and the vagally related HRV [supine LnHF (r = .78, Ln rMSSD (r = .63, and the standing LnHF (r = .73, p < .05] was found. Conclusions: This study showed that an 8 week training program modified particularly fat free mass and short-term endurance, whereas both the autonomic cardiac regulation and the feeling of fatigue remained almost unaffected. Standing position seems to be more sensitive in terms of the HR response in relation to fatigue

The Relationship between Heart Rate Variability and Adiposity Differs for Central and Overall Adiposity

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B. Gwen Windham

2012-01-01

Full Text Available While frank obesity is associated with reduced HRV, indicative of poorer autonomic nervous system (ANS function, the association between body mass index (BMI and HRV is less clear. We hypothesized that effects of adiposity on ANS are mostly mediated by visceral fat and less by subcutaneous fat; therefore, centrally distributed adipose tissue, that is, waist circumference (WC, should be more strongly associated with HRV than overall adiposity (BMI. To examine this hypothesis, we used data collected in a subset of the Baltimore Longitudinal Study of Aging to compare strength of association between HRV and WC to that of HRV and BMI. Time domain HRV variables SDNN (standard deviation of successive differences in normal-to-normal (N-N intervals and RMSSD (root mean square of successive differences in N-N intervals were calculated from 24-hour Holter recordings in 159 participants (29–96 years. Increasing WC was associated with decreasing SDNN and RMSSD in younger but not older participants (P value for WC-by-age interaction = 0.003. BMI was not associated with either SDNN or RMSSD at any age. In conclusion, central adiposity may contribute to sympathetic and parasympathetic ANS declines early in life.

The role of voice therapy in the treatment of dyspnea and dysphonia in a patient with a vagal nerve stimulation device.

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Gillespie, Amanda I; Helou, Leah B; Ingle, John W; Baldwin, Maria; Rosen, Clark A

2014-01-01

Vagal nerve stimulators (VNS) are implanted to treat medically refractory epilepsy and depression. The VNS stimulates the vagus nerve in the left neck. Laryngeal side effects are common and include dysphagia, dysphonia, and dyspnea. The current case study represents a patient with severe dyspnea and dysphonia, persisting even with VNS deactivation. The case demonstrates the use of voice and respiratory retraining therapy for the treatment of VNS-induced dysphonia and dyspnea. It also highlights the importance of a multidisciplinary approach, including laryngology, neurology, and speech-language pathology, in the treatment of these challenging patients. Copyright © 2014 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Blood pressure control with selective vagal nerve stimulation and minimal side effects

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Plachta, Dennis T. T.; Gierthmuehlen, Mortimer; Cota, Oscar; Espinosa, Nayeli; Boeser, Fabian; Herrera, Taliana C.; Stieglitz, Thomas; Zentner, Joseph

2014-06-01

Objective. Hypertension is the largest threat to patient health and a burden to health care systems. Despite various options, 30% of patients do not respond sufficiently to medical treatment. Mechanoreceptors in the aortic arch relay blood pressure (BP) levels through vagal nerve (VN) fibers to the brainstem and trigger the baroreflex, lowering the BP. Selective electrical stimulation of these nerve fibers reduced BP in rats. However, there is no technique described to localize and stimulate these fibers inside the VN without inadvertent stimulation of non-baroreceptive fibers causing side effects like bradycardia and bradypnea. Approach. We present a novel method for selective VN stimulation to reduce BP without the aforementioned side effects. Baroreceptor compound activity of rat VN (n = 5) was localized using a multichannel cuff electrode, true tripolar recording and a coherent averaging algorithm triggered by BP or electrocardiogram. Main results. Tripolar stimulation over electrodes near the barofibers reduced the BP without triggering significant bradycardia and bradypnea. The BP drop was adjusted to 60% of the initial value by varying the stimulation pulse width and duration, and lasted up to five times longer than the stimulation. Significance. The presented method is robust to impedance changes, independent of the electrode's relative position, does not compromise the nerve and can run on implantable, ultra-low power signal processors.

Vagal innervation is required for pulmonary function phenotype in Htr4-/- mice.

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House, John S; Nichols, Cody E; Li, Huiling; Brandenberger, Christina; Virgincar, Rohan S; DeGraff, Laura M; Driehuys, Bastiaan; Zeldin, Darryl C; London, Stephanie J

2017-04-01

Human genome-wide association studies have identified over 50 loci associated with pulmonary function and related phenotypes, yet follow-up studies to determine causal genes or variants are rare. Single nucleotide polymorphisms in serotonin receptor 4 ( HTR4 ) are associated with human pulmonary function in genome-wide association studies and follow-up animal work has demonstrated that Htr4 is causally associated with pulmonary function in mice, although the precise mechanisms were not identified. We sought to elucidate the role of neural innervation and pulmonary architecture in the lung phenotype of Htr4 -/- animals. We report here that the Htr4 -/- phenotype in mouse is dependent on vagal innervation to the lung. Both ex vivo tracheal ring reactivity and in vivo flexiVent pulmonary functional analyses demonstrate that vagotomy abrogates the Htr4 -/- airway hyperresponsiveness phenotype. Hyperpolarized 3 He gas magnetic resonance imaging and stereological assessment of wild-type and Htr4 -/- mice reveal no observable differences in lung volume, inflation characteristics, or pulmonary microarchitecture. Finally, control of breathing experiments reveal substantive differences in baseline breathing characteristics between mice with/without functional HTR4 in breathing frequency, relaxation time, flow rate, minute volume, time of inspiration and expiration and breathing pauses. These results suggest that HTR4's role in pulmonary function likely relates to neural innervation and control of breathing. Copyright © 2017 the American Physiological Society.

Neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats

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Quagliotto, E.; Casali, K.R.; Dal Lago, P.; Rasia-Filho, A.A.

2014-01-01

The rat posterodorsal medial amygdala (MePD) links emotionally charged sensory stimuli to social behavior, and is part of the supramedullary control of the cardiovascular system. We studied the effects of microinjections of neuroactive peptides markedly found in the MePD, namely oxytocin (OT, 10 ng and 25 pg; n=6/group), somatostatin (SST, 1 and 0.05 μM; n=8 and 5, respectively), and angiotensin II (Ang II, 50 pmol and 50 fmol; n=7/group), on basal cardiovascular activity and on baroreflex- and chemoreflex-mediated responses in awake adult male rats. Power spectral and symbolic analyses were applied to pulse interval and systolic arterial pressure series to identify centrally mediated sympathetic/parasympathetic components in the heart rate variability (HRV) and arterial pressure variability (APV). No microinjected substance affected basal parameters. On the other hand, compared with the control data (saline, 0.3 µL; n=7), OT (10 ng) decreased mean AP (MAP 50 ) after baroreflex stimulation and increased both the mean AP response after chemoreflex activation and the high-frequency component of the HRV. OT (25 pg) increased overall HRV but did not affect any parameter of the symbolic analysis. SST (1 μM) decreased MAP 50 , and SST (0.05 μM) enhanced the sympathovagal cardiac index. Both doses of SST increased HRV and its low-frequency component. Ang II (50 pmol) increased HRV and reduced the two unlike variations pattern of the symbolic analysis (P<0.05 in all cases). These results demonstrate neuropeptidergic actions in the MePD for both the increase in the range of the cardiovascular reflex responses and the involvement of the central sympathetic and parasympathetic systems on HRV and APV

Neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats

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Quagliotto, E. [Departamento de Ciências Básicas da Saúde/Fisiologia, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS (Brazil); Programa de Pós-Graduação em Neurociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Casali, K.R. [Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo, São José dos Campos, SP (Brazil); Dal Lago, P. [Departamento de Fisioterapia, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS (Brazil); Rasia-Filho, A.A. [Departamento de Ciências Básicas da Saúde/Fisiologia, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS (Brazil); Programa de Pós-Graduação em Neurociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil)

2014-11-21

The rat posterodorsal medial amygdala (MePD) links emotionally charged sensory stimuli to social behavior, and is part of the supramedullary control of the cardiovascular system. We studied the effects of microinjections of neuroactive peptides markedly found in the MePD, namely oxytocin (OT, 10 ng and 25 pg; n=6/group), somatostatin (SST, 1 and 0.05 μM; n=8 and 5, respectively), and angiotensin II (Ang II, 50 pmol and 50 fmol; n=7/group), on basal cardiovascular activity and on baroreflex- and chemoreflex-mediated responses in awake adult male rats. Power spectral and symbolic analyses were applied to pulse interval and systolic arterial pressure series to identify centrally mediated sympathetic/parasympathetic components in the heart rate variability (HRV) and arterial pressure variability (APV). No microinjected substance affected basal parameters. On the other hand, compared with the control data (saline, 0.3 µL; n=7), OT (10 ng) decreased mean AP (MAP{sub 50}) after baroreflex stimulation and increased both the mean AP response after chemoreflex activation and the high-frequency component of the HRV. OT (25 pg) increased overall HRV but did not affect any parameter of the symbolic analysis. SST (1 μM) decreased MAP{sub 50}, and SST (0.05 μM) enhanced the sympathovagal cardiac index. Both doses of SST increased HRV and its low-frequency component. Ang II (50 pmol) increased HRV and reduced the two unlike variations pattern of the symbolic analysis (P<0.05 in all cases). These results demonstrate neuropeptidergic actions in the MePD for both the increase in the range of the cardiovascular reflex responses and the involvement of the central sympathetic and parasympathetic systems on HRV and APV.

Chronic work stress and decreased vagal tone impairs decision making and reaction time in jockeys.

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Landolt, Kathleen; Maruff, Paul; Horan, Ben; Kingsley, Michael; Kinsella, Glynda; O'Halloran, Paul D; Hale, Matthew W; Wright, Bradley J

2017-10-01

The inverse relationship between acute stress and decision-making is well documented, but few studies have investigated the impact of chronic stress. Jockeys work exhaustive schedules and have extremely dangerous occupations, with safe performance requiring quick reaction time and accurate decision-making. We used the effort reward imbalance (ERI) occupational stress model to assess the relationship of work stress with indices of stress physiology and decision-making and reaction time. Jockeys (N=32) completed computerised cognitive tasks (Cogstate) on two occasions; September and November (naturally occurring lower and higher stress periods), either side of an acute stress test. Higher ERI was correlated with the cortisol awakening responses (high stress r=-0.37; low stress r=0.36), and with decrements in decision-making comparable to having a blood alcohol concentration of 0.08 in the high stress period (pdecision-making. Potentially, this may be attributed to a 'tipping point' whereby the higher ERI reported by jockeys in the high stress period decreases vagal tone, which may contribute to reduced decision-making abilities. Copyright © 2017 Elsevier Ltd. All rights reserved.

Boosting recovery rather than buffering reactivity: Higher stress-induced oxytocin secretion is associated with increased cortisol reactivity and faster vagal recovery after acute psychosocial stress.

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Engert, Veronika; Koester, Anna M; Riepenhausen, Antje; Singer, Tania

2016-12-01

Animal models and human studies using paradigms designed to stimulate endogenous oxytocin release suggest a stress-buffering role of oxytocin. We here examined the involvement of stress-induced peripheral oxytocin secretion in reactivity and recovery phases of the human psychosocial stress response. Healthy male and female participants (N=114) were subjected to a standardized laboratory stressor, the Trier Social Stress Test. In addition to plasma oxytocin, cortisol was assessed as a marker of hypothalamic-pituitary-adrenal (HPA-) axis activity, alpha-amylase and heart rate as markers of sympathetic activity, high frequency heart rate variability as a marker of vagal tone and self-rated anxiety as an indicator of subjective stress experience. On average, oxytocin levels increased by 51% following psychosocial stress. The stress-induced oxytocin secretion, however, did not reduce stress reactivity. To the contrary, higher oxytocin secretion was associated with greater cortisol reactivity and peak cortisol levels in both sexes. In the second phase of the stress response the opposite pattern was observed, with higher oxytocin secretion associated with faster vagal recovery. We suggest that after an early stage of oxytocin and HPA-axis co-activation, the stress-reducing action of oxytocin unfolds. Due to the time lag it manifests as a recovery-boosting rather than a reactivity-buffering effect. By reinforcing parasympathetic autonomic activity, specifically during stress recovery, oxytocin may provide an important protective function against the health-compromising effects of sustained stress. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cardiac Autonomic and Blood Pressure Responses to an Acute Foam Rolling Session.

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Lastova, Kevin; Nordvall, Michael; Walters-Edwards, Michelle; Allnutt, Amy; Wong, Alexei

2018-03-22

Foam Rolling (FR) is a self-myofascial release method that has become extremely popular among athletes and fitness enthusiasts for its ability to improve flexibility and range of motion and alleviate delayed onset muscle soreness. However, the cardiac autonomic modulation and blood pressure (BP) responses induced by an acute FR session are currently unknown. The present study evaluated the effects of an acute session of FR exercise on heart rate variability (HRV) and BP responses in healthy individuals. Fifteen (M=8, F=7) healthy subjects completed either a FR or non-exercise control trial in randomized order. HRV and BP measurements were collected at baseline, 10 and 30 min after each trial. There were significant increases (P < 0.01) in markers of vagal tone (nHF) for 30 min after the FR trial, while no changes from baseline were observed following control. There were also significant decreases (P < 0.05) in markers of sympathetic activity (nLF), sympathovagal balance (nLF/nHF), systolic BP and diastolic BP at 10 and 30 min after the trial KB trial while no changes from baseline were observed after the control trial. Our findings indicate that FR decreases sympathovagal balance for 30 min post-intervention which is concurrent with an important hypotensive effect. Further research is warranted to evaluate the potential cardiovascular protective effects of FR in diverse populations.

Spleen vagal denervation inhibits the production of antibodies to circulating antigens.

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Ruud M Buijs

Full Text Available BACKGROUND: Recently the vagal output of the central nervous system has been shown to suppress the innate immune defense to pathogens. Here we investigated by anatomical and physiological techniques the communication of the brain with the spleen and provided evidence that the brain has the capacity to stimulate the production of antigen specific antibodies by its parasympathetic autonomic output. METHODOLOGY/PRINCIPAL FINDINGS: This conclusion was reached by successively demonstrating that: 1. The spleen receives not only sympathetic input but also parasympathetic input. 2. Intravenous trinitrophenyl-ovalbumin (TNP-OVA does not activate the brain and does not induce an immune response. 3. Intravenous TNP-OVA with an inducer of inflammation; lipopolysaccharide (LPS, activates the brain and induces TNP-specific IgM. 4. LPS activated neurons are in the same areas of the brain as those that provide parasympathetic autonomic information to the spleen, suggesting a feed back circuit between brain and immune system. Consequently we investigated the interaction of the brain with the spleen and observed that specific parasympathetic denervation but not sympathetic denervation of the spleen eliminates the LPS-induced antibody response to TNP-OVA. CONCLUSIONS/SIGNIFICANCE: These findings not only show that the brain can stimulate antibody production by its autonomic output, it also suggests that the power of LPS as adjuvant to stimulate antibody production may also depend on its capacity to activate the brain. The role of the autonomic nervous system in the stimulation of the adaptive immune response may explain why mood and sleep have an influence on antibody production.

Evidence for glutamatergic mechanisms in the vagal sensory pathway initiating cardiorespiratory reflexes in the shorthorn sculpin Myoxocephalus scorpius.

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Sundin, L; Turesson, J; Taylor, E W

2003-03-01

Glutamate is a major neurotransmitter of chemoreceptor and baroreceptor afferent pathways in mammals and therefore plays a central role in the development of cardiorespiratory reflexes. In fish, the gills are the major sites of these receptors, and, consequently, the terminal field (sensory area) of their afferents (glossopharyngus and vagus) in the medulla must be an important site for the integration of chemoreceptor and baroreceptor signals. This investigation explored whether fish have glutamatergic mechanisms in the vagal sensory area (Xs) that could be involved in the generation of cardiorespiratory reflexes. The locations of the vagal sensory and motor (Xm) areas in the medulla were established by the orthograde and retrograde axonal transport of the neural tract tracer Fast Blue following its injection into the ganglion nodosum. Glutamate was then microinjected into identified sites within the Xs in an attempt to mimic chemoreceptor- and baroreceptor-induced reflexes commonly observed in fish. By necessity, the brain injections were performed on anaesthetised animals that were fixed by 'eye bars' in a recirculating water system. Blood pressure and heart rate were measured using an arterial cannula positioned in the afferent branchial artery of the 3rd gill arch, and ventilation was measured by impedance probes sutured onto the operculum. Unilateral injection of glutamate (40-100 nl, 10 mmol l(-1)) into the Xs caused marked cardiorespiratory changes. Injection (0.1-0.3 mm deep) in different rostrocaudal, medial-lateral positions induced a bradycardia, either increased or decreased blood pressure, ventilation frequency and amplitude and, sometimes, an initial apnea. Often these responses occurred simultaneously in various different combinations but, occasionally, they appeared singly, suggesting specific projections into the Xs for each cardiorespiratory variable and local determination of the modality of the response. Response patterns related to

Coping Style Modifies General and Affective Autonomic Reactions of Domestic Pigs in Different Behavioral Contexts

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Annika Krause

2017-05-01

Full Text Available Based on individual adaptive strategies (coping, animals may react differently to environmental challenges in terms of behavior and physiology according to their emotional perception. Emotional valence as well as arousal may be derived by measuring vagal and sympathetic tone of the autonomic nervous system (ANS. We investigated the situation-dependent autonomic response of 16 domestic pigs with either a reactive or a proactive coping style, previously selected according to the backtest which is accepted in piglets to assess escape behavior. At 11 weeks of age, the pigs were equipped with an implantable telemetric device, and heart rate (HR, blood pressure (BP and their respective variabilities (HRV, BPV were recorded for 1 h daily over a time period of 10 days and analyzed in four behavioral contexts (resting, feeding, idling, handling. Additionally, the first minute of feeding and handling was used for a short-term analysis of these parameters in 10-s intervals. Data from day 1–3 (period 1 and day 8–10 (period 2 were grouped into two separate periods. Our results revealed general differences between the coping styles during feeding, resting and handling, with proactive pigs showing higher HR compared to reactive pigs. This elevated HR was based on either lower vagal (resting or elevated sympathetic activation (feeding, handling. The short-term analysis of the autonomic activation during feeding revealed a physiological anticipation reaction in proactive pigs in period 1, whereas reactive pigs showed this reaction only in period 2. Food intake was characterized by sympathetic arousal with concurrent vagal withdrawal, which was more pronounced in proactive pigs. In contrast, neither coping style resulted in an anticipation reaction to handling. Vagal activation increased in reactive pigs during handling, while proactive pigs showed an increase in sympathetically driven arousal in period 2. Our findings confirm significant context

Linear and nonlinear analysis of heart rate variability in healthy subjects and after acute myocardial infarction in patients

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V.C. Kunz

2012-05-01

Full Text Available The objectives of this study were to evaluate and compare the use of linear and nonlinear methods for analysis of heart rate variability (HRV in healthy subjects and in patients after acute myocardial infarction (AMI. Heart rate (HR was recorded for 15 min in the supine position in 10 patients with AMI taking β-blockers (aged 57 ± 9 years and in 11 healthy subjects (aged 53 ± 4 years. HRV was analyzed in the time domain (RMSSD and RMSM, the frequency domain using low- and high-frequency bands in normalized units (nu; LFnu and HFnu and the LF/HF ratio and approximate entropy (ApEn were determined. There was a correlation (P < 0.05 of RMSSD, RMSM, LFnu, HFnu, and the LF/HF ratio index with the ApEn of the AMI group on the 2nd (r = 0.87, 0.65, 0.72, 0.72, and 0.64 and 7th day (r = 0.88, 0.70, 0.69, 0.69, and 0.87 and of the healthy group (r = 0.63, 0.71, 0.63, 0.63, and 0.74, respectively. The median HRV indexes of the AMI group on the 2nd and 7th day differed from the healthy group (P < 0.05: RMSSD = 10.37, 19.95, 24.81; RMSM = 23.47, 31.96, 43.79; LFnu = 0.79, 0.79, 0.62; HFnu = 0.20, 0.20, 0.37; LF/HF ratio = 3.87, 3.94, 1.65; ApEn = 1.01, 1.24, 1.31, respectively. There was agreement between the methods, suggesting that these have the same power to evaluate autonomic modulation of HR in both AMI patients and healthy subjects. AMI contributed to a reduction in cardiac signal irregularity, higher sympathetic modulation and lower vagal modulation.

Autonomic Recovery Is Delayed in Chinese Compared with Caucasian following Treadmill Exercise.

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Peng Sun

Full Text Available Caucasian populations have a higher prevalence of cardiovascular disease (CVD when compared with their Chinese counterparts and CVD is associated with autonomic function. It is unknown whether autonomic function during exercise recovery differs between Caucasians and Chinese. The present study investigated autonomic recovery following an acute bout of treadmill exercise in healthy Caucasians and Chinese. Sixty-two participants (30 Caucasian and 32 Chinese, 50% male performed an acute bout of treadmill exercise at 70% of heart rate reserve. Heart rate variability (HRV and baroreflex sensitivity (BRS were obtained during 5-min epochs at pre-exercise, 30-min, and 60-min post-exercise. HRV was assessed using frequency [natural logarithm of high (LnHF and low frequency (LnLF powers, normalized high (nHF and low frequency (nLF powers, and LF/HF ratio] and time domains [Root mean square of successive differences (RMSSD, natural logarithm of RMSSD (LnRMSSD and R-R interval (RRI]. Spontaneous BRS included both up-up and down-down sequences. At pre-exercise, no group differences were observed for any HR, HRV and BRS parameters. During exercise recovery, significant race-by-time interactions were observed for LnHF, nHF, nLF, LF/HF, LnRMSSD, RRI, HR, and BRS (up-up. The declines in LnHF, nHF, RMSSD, RRI and BRS (up-up and the increases in LF/HF, nLF and HR were blunted in Chinese when compared to Caucasians from pre-exercise to 30-min to 60-min post-exercise. Chinese exhibited delayed autonomic recovery following an acute bout of treadmill exercise. This delayed autonomic recovery may result from greater sympathetic dominance and extended vagal withdrawal in Chinese.Chinese Clinical Trial Register ChiCTR-IPR-15006684.

Autonomic Recovery Is Delayed in Chinese Compared with Caucasian following Treadmill Exercise.

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Sun, Peng; Yan, Huimin; Ranadive, Sushant M; Lane, Abbi D; Kappus, Rebecca M; Bunsawat, Kanokwan; Baynard, Tracy; Hu, Min; Li, Shichang; Fernhall, Bo

2016-01-01

Caucasian populations have a higher prevalence of cardiovascular disease (CVD) when compared with their Chinese counterparts and CVD is associated with autonomic function. It is unknown whether autonomic function during exercise recovery differs between Caucasians and Chinese. The present study investigated autonomic recovery following an acute bout of treadmill exercise in healthy Caucasians and Chinese. Sixty-two participants (30 Caucasian and 32 Chinese, 50% male) performed an acute bout of treadmill exercise at 70% of heart rate reserve. Heart rate variability (HRV) and baroreflex sensitivity (BRS) were obtained during 5-min epochs at pre-exercise, 30-min, and 60-min post-exercise. HRV was assessed using frequency [natural logarithm of high (LnHF) and low frequency (LnLF) powers, normalized high (nHF) and low frequency (nLF) powers, and LF/HF ratio] and time domains [Root mean square of successive differences (RMSSD), natural logarithm of RMSSD (LnRMSSD) and R-R interval (RRI)]. Spontaneous BRS included both up-up and down-down sequences. At pre-exercise, no group differences were observed for any HR, HRV and BRS parameters. During exercise recovery, significant race-by-time interactions were observed for LnHF, nHF, nLF, LF/HF, LnRMSSD, RRI, HR, and BRS (up-up). The declines in LnHF, nHF, RMSSD, RRI and BRS (up-up) and the increases in LF/HF, nLF and HR were blunted in Chinese when compared to Caucasians from pre-exercise to 30-min to 60-min post-exercise. Chinese exhibited delayed autonomic recovery following an acute bout of treadmill exercise. This delayed autonomic recovery may result from greater sympathetic dominance and extended vagal withdrawal in Chinese. Chinese Clinical Trial Register ChiCTR-IPR-15006684.

Reduction in Heart Rate Variability with Traffic and Air Pollution in Patients with Coronary Artery Disease

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Zanobetti, Antonella; Gold, Diane R.; Stone, Peter H.; Suh, Helen H.; Schwartz, Joel; Coull, Brent A.; Speizer, Frank E.

2010-01-01

Introduction Ambient particulate pollution and traffic have been linked to myocardial infarction and cardiac death risk. Possible mechanisms include autonomic cardiac dysfunction. Methods In a repeated-measures study of 46 patients 43–75 years of age, we investigated associations of central-site ambient particulate pollution, including black carbon (BC) (a marker for regional and local traffic), and report of traffic exposure with changes in half-hourly averaged heart rate variability (HRV), a marker of autonomic function measured by 24-hr Holter electrocardiogram monitoring. Each patient was observed up to four times within 1 year after a percutaneous intervention for myocardial infarction, acute coronary syndrome without infarction, or stable coronary artery disease (4,955 half-hour observations). For each half-hour period, diary data defined whether the patient was home or not home, or in traffic. Results A decrease in high frequency (HF; an HRV marker of vagal tone) of −16.4% [95% confidence interval (CI), −20.7 to −11.8%] was associated with an interquartile range of 0.3-μg/m3 increase in prior 5-day averaged ambient BC. Decreases in HF were independently associated both with the previous 2-hr averaged BC (−10.4%; 95% CI, −15.4 to −5.2%) and with being in traffic in the previous 2 hr (−38.5%; 95% CI, −57.4 to −11.1%). We also observed independent responses for particulate air matter with aerodynamic diameter ≤ 2.5 μm and for gases (ozone or nitrogen dioxide). Conclusion After hospitalization for coronary artery disease, both particulate pollution and being in traffic, a marker of stress and pollution, were associated with decreased HRV. PMID:20064780

Fasting and meal-induced CCK and PP secretion following intragastric balloon treatment for obesity

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Mathus-Vliegen, Elisabeth M. H.; de Groot, Gerrit H.

2013-01-01

Satiety is centrally and peripherally mediated by gastrointestinal peptides and the vagal nerve. We aimed to investigate whether intragastric balloon treatment affects satiety through effects on fasting and meal-stimulated cholecystokinin (CCK) and pancreatic polypeptide (PP) secretion. Patients

Prenatal nicotinic exposure upregulates pulmonary C-fiber NK1R expression to prolong pulmonary C-fiber-mediated apneic response

International Nuclear Information System (INIS)

Zhao, Lei; Zhuang, Jianguo; Zang, Na; Lin, Yong; Lee, Lu-Yuan; Xu, Fadi

2016-01-01

Prenatal nicotinic exposure (PNE) prolongs bronchopulmonary C-fiber (PCF)-mediated apneic response to intra-atrial bolus injection of capsaicin in rat pups. The relevant mechanisms remain unclear. Pulmonary substance P and adenosine and their receptors (neurokinin-A receptor, NK1R and ADA 1 receptor, ADA 1 R) and transient receptor potential cation channel subfamily V member 1 (TRPV1) expressed on PCFs are critical for PCF sensitization and/or activation. Here, we compared substance P and adenosine in BALF and NK1R, ADA 1 R, and TRPV1 expression in the nodose/jugular (N/J) ganglia (vagal pulmonary C-neurons retrogradely labeled) between Ctrl and PNE pups. We found that PNE failed to change BALF substance P and adenosine content, but significantly upregulated both mRNA and protein TRPV1 and NK1R in the N/J ganglia and only NK1R mRNA in pulmonary C-neurons. To define the role of NK1R in the PNE-induced PCF sensitization, the apneic response to capsaicin (i.v.) without or with pretreatment of SR140333 (a peripheral and selective NK1R antagonist) was compared and the prolonged apnea by PNE significantly shortened by SR140333. To clarify if the PNE-evoked responses depended on action of nicotinic acetylcholine receptors (nAChRs), particularly α7nAChR, mecamylamine or methyllycaconitine (a general nAChR or a selective α7nAChR antagonist) was administrated via another mini-pump over the PNE period. Mecamylamine or methyllycaconitine eliminated the PNE-evoked mRNA and protein responses. Our data suggest that PNE is able to elevate PCF NK1R expression via activation of nAChRs, especially α7nAChR, which likely contributes to sensitize PCFs and prolong the PCF-mediated apneic response to capsaicin. - Highlights: • PNE upregulated NK1R and TRPV1 gene and protein expression in the N/J ganglia. • PNE only elevated NK1R mRNA in vagal pulmonary C-neurons. • Blockage of peripheral NK1R reduced the PNE-induced PCF sensitization. • PNE induced gene and protein changes in

Prediction of tonic parasympathetic cardiac control using respiratory sinus arrhythmia: the need for respiratory control

NARCIS (Netherlands)

GROSSMAN, P.; Karemaker, J.; Wieling, W.

1991-01-01

Respiratory sinus arrhythmia (RSA) has received much attention in recent years due to the large body of evidence indicating that variations in this phenomenon represent alterations in parasympathetic cardiac control. Although it appears that respiratory sinus arrhythmia is mediated by vagal

The TIR-domain containing adaptor TRAM is required for TLR7 mediated RANTES production.

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Enda Shevlin

Full Text Available Toll-like receptor 7 (TLR7 plays a vital role in the immune response to ssRNA viruses such as human rhinovirus (HRV and Influenza, against which there are currently no treatments or vaccines with long term efficacy available. Clearly, a more comprehensive understanding of the TLR7 signaling axis will contribute to its molecular targeting. TRIF related adaptor molecule (TRAM plays a vital role in TLR4 signaling by recruiting TRIF to TLR4, followed by endosomal trafficking of the complex and initiation of IRF3 dependent type I interferon production as well as NF-κB dependent pro-inflammatory cytokine production. Towards understanding the molecular mechanisms that regulate TLR7 functionality, we found that TRAM(-/- murine macrophages exhibited a transcriptional and translational impairment in TLR7 mediated RANTES, but not TNFα, production. Suppression of TRAM expression in human macrophages also resulted in an impairment in TLR7 mediated CCL5 and IFN-β, but not TNFα, gene induction. Furthermore, suppression of endogenous human TRAM expression in human macrophages significantly impaired RV16 induced CCL5 and IFNβ, but not TNFα gene induction. Additionally, TRAM-G2A dose-dependently inhibited TLR7 mediated activation of CCL5, IFNβ and IFNα reporter genes. TLR7-mediated phosphorylation and nuclear translocation of IRF3 was impaired in TRAM(-/- cells. Finally, co-immunoprecipitation studies indicated that TRAM physically interacts with MyD88 upon TLR7 stimulation, but not under basal conditions. Our results clearly demonstrate that TRAM plays a, hitherto unappreciated, role in TLR7 signaling through a novel signaling axis containing, but not limited to, MyD88, TRAM and IRF3 towards the activation of anti-viral immunity.

Exercise-induced ventricular arrhythmias and vagal dysfunction in Chagas disease patients with no apparent cardiac involvement

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Henrique Silveira Costa

2015-04-01

Full Text Available INTRODUCTION : Exercise-induced ventricular arrhythmia (EIVA and autonomic imbalance are considered as early markers of heart disease in Chagas disease (ChD patients. The objective of the present study was to verify the differences in the occurrence of EIVA and autonomic maneuver indexes between healthy individuals and ChD patients with no apparent cardiac involvement. METHODS : A total of 75 ChD patients with no apparent cardiac involvement, aged 44.7 (8.5 years, and 38 healthy individuals, aged 44.0 (9.2 years, were evaluated using echocardiography, symptom-limited treadmill exercise testing and autonomic function tests. RESULTS : The occurrence of EIVA was higher in the chagasic group (48% than in the control group (23.7% during both the effort and the recovery phases. Frequent ventricular contractions occurred only in the patient group. Additionally, the respiratory sinus arrhythmia index was significantly lower in the chagasic individuals compared with the control group. CONCLUSIONS : ChD patients with no apparent cardiac involvement had a higher frequency of EIVA as well as more vagal dysfunction by respiratory sinus arrhythmia. These results suggest that even when asymptomatic, ChD patients possess important arrhythmogenic substrates and subclinical disease.

The Gut's Little Brain in Control of Intestinal Immunity

NARCIS (Netherlands)

de Jonge, Wouter J.

2013-01-01

The gut immune system shares many mediators and receptors with the autonomic nervous system. Good examples thereof are the parasympathetic (vagal) and sympathetic neurotransmitters, for which many immune cell types in a gut context express receptors or enzymes required for their synthesis. For some

Preliminary findings of cerebral responses on transcutaneous vagal nerve stimulation on experimental heat pain.

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Usichenko, Taras; Laqua, René; Leutzow, Bianca; Lotze, Martin

2017-02-01

Transcutaneous vagal nerve stimulation (TVNS) is a promising complementary method of pain relief. However, the neural networks associated with its analgesic effects are still to be elucidated. Therefore, we conducted two functional magnetic resonance imaging (fMRI) sessions, in a randomized order, with twenty healthy subjects who were exposed to experimental heat pain stimulation applied to the right forearm using a Contact Heat-Evoked Potential Stimulator. While in one session TVNS was administered bilaterally to the concha auriculae with maximal, non-painful intensity, the stimulation device was switched off in the other session (placebo condition). Pain thresholds were measured before and after each session. Heat stimulation elicited fMRI activation in cerebral pain processing regions. Activation magnitude in the secondary somatosensory cortex, posterior insula, anterior cingulate and caudate nucleus was associated with heat stimulation without TVNS. During TVNS, this association was only seen for the right anterior insula. TVNS decreased fMRI signals in the anterior cingulate cortex in comparison with the placebo condition; however, there was no relevant pain reducing effect over the group as a whole. In contrast, TVNS compared to the placebo condition showed an increased activation in the primary motor cortex, contralateral to the site of heat stimulation, and in the right amygdala. In conclusion, in the protocol used here, TVNS specifically modulated the cerebral response to heat pain, without having a direct effect on pain thresholds.

Inflammatory cytokine response and reduced heart rate variability in newborns with hypoxic-ischemic encephalopathy.

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Al-Shargabi, T; Govindan, R B; Dave, R; Metzler, M; Wang, Y; du Plessis, A; Massaro, A N

2017-06-01

To determine whether systemic inflammation-modulating cytokine expression is related to heart rate variability (HRV) in newborns with hypoxic-ischemic encephalopathy (HIE). The data from 30 newborns with HIE were analyzed. Cytokine levels (IL-2, IL-4, IL-6, IL-8, IL-10, IL-13, IL-1β, TNF-α, IFN-λ) were measured either at 24 h of cooling (n=5), 72 h of cooling (n=4) or at both timepoints (n=21). The following HRV metrics were quantified in the time domain: alpha_S, alpha_L, root mean square (RMS) at short time scales (RMS_S), RMS at long time scales (RMS_L), while low-frequency power (LF) and high-frequency power (HF) were quantified in the frequency domain. The relationships between HRV metrics and cytokines were evaluated using mixed-models. IL-6, IL-8, IL-10, and IL-13 levels were inversely related to selected HRV metrics. Inflammation-modulating cytokines may be important mediators in the autonomic dysfunction observed in newborns with HIE.

Capturing the cardiac effects of racial discrimination: Do the effects "keep going"?

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Hoggard, Lori S; Hill, LaBarron K; Gray, DeLeon L; Sellers, Robert M

2015-08-01

Racial discrimination negatively impacts cardiac functioning, but few studies examine the more distal cardiac effects of racial discrimination experiences. The present study examined the momentary and prolonged impact of lab-based intergroup and intragroup racial discrimination on heart rate variability (HRV) and heart rate (HR) in a sample (N = 42) of African American (AA) women across two days. On day one, the women were exposed to simulated racial discrimination from either a European American (EA) or AA confederate in the lab. On day two, the women returned to the lab for additional physiological recording and debriefing. Women insulted by the EA confederate exhibited lower HRV on day one and marginally lower HRV on day two. These women also exhibited marginally higher HR on day two. The HRV and HR effects on day two were not mediated by differences in perseveration about the stressor. The findings indicate that racial discrimination - particularly intergroup racial discrimination - may have both momentary and prolonged effects on cardiac activity in AAs. Copyright © 2015 Elsevier B.V. All rights reserved.

Prolonged cardiac effects of momentary assessed stressful events and worry episodes.

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Pieper, Suzanne; Brosschot, Jos F; van der Leeden, Rien; Thayer, Julian F

2010-07-01

To test the hypothesize that increased heart rate (HR) and decreased heart rate variability (HRV) are not only due to concurrent stressful events and worries but also to stressors and worries occurring in the preceding hours or stressors anticipated to occur in the next hour. Worry was expected to mediate at least part of the prolonged effects of stressors. Ambulatory HR and HRV of 73 teachers were recorded for 4 days, during which the participants reported occurrence and duration of worry episodes and stressful events on an hourly basis, using computerized diaries. Multilevel regression models were used, accounting for effects of several biobehavioral variables. Stressful events were not associated with changes in HR or HRV. However, worry episodes had effects on concurrent HR and HRV (2.55 beats/minute; -5.76 milliseconds) and HR and HRV in the succeeding hour (3.05 beats/minute; -5.80 milliseconds) and 2 hours later (1.52 beats/minute; -3.14 milliseconds). These findings were independent of emotions, physical activity, posture, and other biobehavioral factors. Worry has effects on cardiac activity, and these effects were still visible after 2 hours. The latter finding suggests that a considerable part of prolonged activation may be induced by unconscious stress-related cognition.

Restoration of euglycemia after duodenal bypass surgery is reliant on central and peripheral inputs in Zucker fa/fa rats.

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Jiao, Jian; Bae, Eun Ju; Bandyopadhyay, Gautam; Oliver, Jason; Marathe, Chaitra; Chen, Michael; Hsu, Jer-Yuan; Chen, Yu; Tian, Hui; Olefsky, Jerrold M; Saberi, Maziyar

2013-04-01

Gastrointestinal bypass surgeries that result in rerouting and subsequent exclusion of nutrients from the duodenum appear to rapidly alleviate hyperglycemia and hyperinsulinemia independent of weight loss. While the mechanism(s) responsible for normalization of glucose homeostasis remains to be fully elucidated, this rapid normalization coupled with the well-known effects of vagal inputs into glucose homeostasis suggests a neurohormonally mediated mechanism. Our results show that duodenal bypass surgery on obese, insulin-resistant Zucker fa/fa rats restored insulin sensitivity in both liver and peripheral tissues independent of body weight. Restoration of normoglycemia was attributable to an enhancement in key insulin-signaling molecules, including insulin receptor substrate-2, and substrate metabolism through a multifaceted mechanism involving activation of AMP-activated protein kinase and downregulation of key regulatory genes involved in both lipid and glucose metabolism. Importantly, while central nervous system-derived vagal nerves were not essential for restoration of insulin sensitivity, rapid normalization in hepatic gluconeogenic capacity and basal hepatic glucose production required intact vagal innervation. Lastly, duodenal bypass surgery selectively altered the tissue concentration of intestinally derived glucoregulatory hormone peptides in a segment-specific manner. The present data highlight and support the significance of vagal inputs and intestinal hormone peptides toward normalization of glucose and lipid homeostasis after duodenal bypass surgery.

Appetite suppression through smelling of dark chocolate correlates with changes in ghrelin in young women

NARCIS (Netherlands)

Massolt, Elske T.; van Haard, Paul M.; Rehfeld, Jens F.; Posthuma, Eduardus F.; van der Veer, Eveline; Schweitzer, Dave H.

2010-01-01

Cephalic effects on appetite are mediated by vagal tone and altered gastrointestinal hormones. The objective of this study is to explore the relationship between appetite and levels of gastrointestinal hormones after smelling chocolate and after melt-and-swallow 30 g chocolate (1.059 oz, 85% cocoa,

Non-invasive Vagal Nerve Stimulation Effects on Hyperarousal and Autonomic State in Patients with Posttraumatic Stress Disorder and History of Mild Traumatic Brain Injury: Preliminary Evidence

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Damon G. Lamb

2017-07-01

Full Text Available Posttraumatic stress disorder (PTSD is a reaction to trauma that results in a chronic perception of threat, precipitating mobilization of the autonomic nervous system, and may be reflected by chronic disinhibition of limbic structures. A common injury preceding PTSD in veterans is mild traumatic brain injury (mTBI. This may be due to the vulnerability of white matter in these networks and such damage may affect treatment response. We evaluated transcutaneous vagal nerve stimulation (tVNS, a non-invasive, low-risk approach that may alter the functions of the limbo-cortical and peripheral networks underlying the hyperarousal component of PTSD and thus improve patient health and well-being. In this single visit pilot study evaluating the impact of tVNS in 22 combat veterans, we used a between-subjects design in people with either PTSD with preceding mTBI or healthy controls. Participants were randomized into stimulation or sham groups and completed a posturally modulated autonomic assessment and emotionally modulated startle paradigm. The primary measures used were respiratory sinus arrhythmia (high-frequency heart rate variability during a tilt-table procedure derived from an electrocardiogram, and skin conductance changes in response to acoustic startle while viewing emotional images (International Affective Picture System. The stimulation was well tolerated and resulted in improvements in vagal tone and moderation of autonomic response to startle, consistent with modulation of autonomic state and response to stress in this population. Our results suggest that tVNS affects systems underlying emotional dysregulation in this population and, therefore, should be further evaluated and developed as a potential treatment tool for these patients.

Influence balneotherapy on spa Truskavets’ with taking Canephron® N on urina lithogenicity and its metabolic and neuroendocrine-immune accompaniments in patients with chronic pyelonephrite and cholecystite

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Oleksandr V. Shulyak

2015-11-01

i.popovych@biph.kiev.ua   SUMMARY Objective. We know that balneotherapy on spa Truskavets' did not significantly affect the parameters of urina Lithogenicity, including Ca/Mg ratio, so search for means of reducing urina Lithogenicity remains relevant. We also know that Phytopreparation Canephron® N recommended for inclusion in complex therapy of chronic pyelonephrite as effective elimination of infectious kidney inflammation, prevention of recurrence of inflammation and lithogenese. Aim: to find out the possibility of reducing urina Lithogenicity influenced balneotherapy on spa Truskavets' by additional taking Canephron® N. Results. Standardized balneotherapy not significantly affect urina Lithogenicity in patients with chronic pyelonephrite and cholecystite, even showed a trend to increase, while additional use Canephron® N significantly reduces urina Lithogenicity by reducing the concentration of Uric acid and downward trend Calcium. Reducing urina Lithogenicity accompanied by a decrease urina concentration Chloride and Potassium, and Baevskiy’s Activity Regulatory Systems Index, Asymmetry δ-, θ- and α-rhythms of background EEG and α-rhythm normalized Power Spectrum Density (PSD in right loci Fp2, F8, T6 and O2, while HRV markers of vagal tone (RMSSD, pNN50, TI also Frequency Deviation θ- and β-rhythms, Amplitude β- and δ-rhythms, δ-rhythm PSD in loci Fp2, F8, T3, T5, O1, O2, β-rhythm PSD in loci Fp1, F4 and θ-rhythm PSD in loci T3 and F7 rising. However, Canephron® N preventes or reverses increasing Uric acid plasma level, Mineralocorticoide Activity, Sympathetic tone, Baevskiy’s Stress Index and PSD ULF HRV also decreasing PSD VLF HRV. Concerning parameters of Immunity Canephron® N decreases blood level active T-Lymphocytes but increases level B-Lymphocytes, Stubnucleary Neutrophiles and total Leukocytes also prevents or reverses increasing CD16+ NK-Lymphocytes, CD8+ and Theophilinesensitive T-Lymphocytes, Monocytes and serum IgM also

Prenatal nicotinic exposure upregulates pulmonary C-fiber NK1R expression to prolong pulmonary C-fiber-mediated apneic response

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Zhao, Lei; Zhuang, Jianguo; Zang, Na; Lin, Yong [Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, NM (United States); Lee, Lu-Yuan [Department of Physiology, University of Kentucky, Lexington, KY (United States); Xu, Fadi, E-mail: fxu@lrri.org [Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, NM (United States); Department of Physiology, University of Kentucky, Lexington, KY (United States)

2016-01-01

Prenatal nicotinic exposure (PNE) prolongs bronchopulmonary C-fiber (PCF)-mediated apneic response to intra-atrial bolus injection of capsaicin in rat pups. The relevant mechanisms remain unclear. Pulmonary substance P and adenosine and their receptors (neurokinin-A receptor, NK1R and ADA{sub 1} receptor, ADA{sub 1}R) and transient receptor potential cation channel subfamily V member 1 (TRPV1) expressed on PCFs are critical for PCF sensitization and/or activation. Here, we compared substance P and adenosine in BALF and NK1R, ADA{sub 1}R, and TRPV1 expression in the nodose/jugular (N/J) ganglia (vagal pulmonary C-neurons retrogradely labeled) between Ctrl and PNE pups. We found that PNE failed to change BALF substance P and adenosine content, but significantly upregulated both mRNA and protein TRPV1 and NK1R in the N/J ganglia and only NK1R mRNA in pulmonary C-neurons. To define the role of NK1R in the PNE-induced PCF sensitization, the apneic response to capsaicin (i.v.) without or with pretreatment of SR140333 (a peripheral and selective NK1R antagonist) was compared and the prolonged apnea by PNE significantly shortened by SR140333. To clarify if the PNE-evoked responses depended on action of nicotinic acetylcholine receptors (nAChRs), particularly α7nAChR, mecamylamine or methyllycaconitine (a general nAChR or a selective α7nAChR antagonist) was administrated via another mini-pump over the PNE period. Mecamylamine or methyllycaconitine eliminated the PNE-evoked mRNA and protein responses. Our data suggest that PNE is able to elevate PCF NK1R expression via activation of nAChRs, especially α7nAChR, which likely contributes to sensitize PCFs and prolong the PCF-mediated apneic response to capsaicin. - Highlights: • PNE upregulated NK1R and TRPV1 gene and protein expression in the N/J ganglia. • PNE only elevated NK1R mRNA in vagal pulmonary C-neurons. • Blockage of peripheral NK1R reduced the PNE-induced PCF sensitization. • PNE induced gene and protein

Association of physical capacity with heart rate variability based on a short-duration measurement of resting pulse rate in older adults with obesity.

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Chun-De Liao

Full Text Available Obesity can limit physical capacity and lower physical activity levels in elderly people. Low physical activity levels may be mediated by autonomic dysfunction with decreased heart rate variability (HRV. However, the relationship between autonomic dysfunction and low physical capability remains unclear. This cross-sectional study investigated the association of low physical capability with HRV in older adults with obesity.We recruited 231 old man and 210 old women with a mean (range age of 65.5 (51-78 and 62.9 (52-76 years, respectively. Physical capability was measured using mobility tasks, including functional reach, single-leg stance (SLS, gait speed (GS, timed up and go, and timed chair rise (TCR, and the scores on these tasks were merged and transformed into a global physical capability score (GPCS. HRV was measured using a 7-min resting pulse-based technique, and the time- and frequency-domain indices of HRV were obtained including standard deviation of normal-to-normal intervals (SDNN, root mean square of successive differences at rest (rMSSD, and high-frequency (HF power. All HRV indices were natural log (ln transformed for analysis. Participants were divided into high, moderate, and low physical-capability groups according to their physical performance. Multivariate analysis of covariance was performed to test differences in HRV indices among physical-capability groups with participants' characteristics serving as covariates. A stepwise regression model was established to identify the determinants of HRV indices. We used hierarchical regression analysis to identify the association of the GPCS with HRV indices.In both men and women, the low physical-capability group exhibited significantly increased heart rate (P <0.05 and decreased HRV in terms of a decreased ln[SDNN] (P <0.001, ln[rMSSD] (P <0.05 and ln[HF] (P <0.05, compared with the high physical-capability group. GS positively predicted ln[SDNN], whereas SLS, GS, and TCR were

Pozorování aktivity autonomního nervového systému prostřednictvím spektrální analýzy variability srdeční frekvence u hráčů ledního hokeje Autonomic nervous system observation through to use of spectral analysis of heart rate variability in ice hockey players

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Iva Řehová

2007-01-01

Full Text Available Cílem studie bylo poodhalit vliv pravidelného sportovního tréninku na aktivitu autonomního nervového systému (ANS, která byla hodnocena pomocí spektrální analýzy variability srdeční frekvence (SA HRV. K vyhodnocení výsledků SA HRV byly použity komplexní indexy (celkové skóre – TS, aktivita vagu – VA, sympatovagová balance – SVB a věkově standardizovaná hodnota celkového spektrálního výkonu (PT (Stejskal et al., 2002. Výzkumný soubor tvořili čtyři hráči ledního hokeje. Na základě získaných výsledků jsme došli k závěru, že kvalita sportovního tréninku ovlivňuje aktivitu ANS. Změny aktivity ANS, a tím velikosti adaptability sportovce, mohou významně ovlivnit sportovní výkon. Optimalizace adaptačních procesů prostřednictvím kontroly tréninkového zatížení na základě měření SA HRV může přinést nové aspekty řízení sportovního tréninku. The aim of our study was to investigate the infl uence of regular sport training on the activity of the autonomic nervous system (ANS and to disclose patterns of interrelations between them. The activity of the ANS was evaluated by means of the spectral analysis of heart rate variability (SA HRV. We used complex indices (total score – TS, vagal activity – VA, sympathovagal balance – SVB and age standardized values of total spectral power (PT for SA HRV results evaluation (Stejskal et al., 2002. The study group consisted of four ice hockey players, of whom all were 17 years old. The SA HRV was monitored by using VarCor PF7 hardware and VarCorMulti computer software, which enables four individuals to be measured at the same time. The examination of heart rate variability took place once a week in the morning. Information about the previous day’s training load, the duration and quality of sleep, and their self-reported health status (SRH was also obtained by completing a questionnaire before the SA HRV examination. Overall sports

Effects of metronome breathing on the assessment of autonomic control using heart rate variability

NARCIS (Netherlands)

Haaksma, J; Brouwer, J; vandenBerg, MP; Dijk, WA; Dassen, WRM; Crijns, HJGM; Mulder, Lambertus; Mulder, Gysbertus

1996-01-01

Analysis of Heart Rate Variability is a non-invasive quantitative tool to study the influence of the autonomic nervous system on the heart. Rapid variations in heart rate, related to breathing are primarily mediated by the vagal limb of the autonomic nervous system. The resulting variations in heart

Physiological Mechanisms Mediating the Coupling between Heart Period and Arterial Pressure in Response to Postural Changes in Humans.

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Silvani, Alessandro; Calandra-Buonaura, Giovanna; Johnson, Blair D; van Helmond, Noud; Barletta, Giorgio; Cecere, Anna G; Joyner, Michael J; Cortelli, Pietro

2017-01-01

The upright posture strengthens the coupling between heart period (HP) and systolic arterial pressure (SAP) consistently with a greater contribution of the arterial baroreflex to cardiac control, while paradoxically decreasing cardiac baroreflex sensitivity (cBRS). To investigate the physiological mechanisms that mediate the coupling between HP and SAP in response to different postures, we analyzed the cross-correlation functions between low-frequency HP and SAP fluctuations and estimated cBRS with the sequence technique in healthy male subjects during passive head-up tilt test (HUTT, n = 58), during supine wakefulness, supine slow-wave sleep (SWS), and in the seated and active standing positions ( n = 8), and during progressive loss of 1 L blood ( n = 8) to decrease central venous pressure in the supine position. HUTT, SWS, the seated, and the standing positions, but not blood loss, entailed significant increases in the positive correlation between HP and the previous SAP values, which is the expected result of arterial baroreflex control, compared with baseline recordings in the supine position during wakefulness. These increases were mirrored by increases in the low-frequency variability of SAP in each condition but SWS. cBRS decreased significantly during HUTT, in the seated and standing positions, and after blood loss compared with baseline during wakefulness. These decreases were mirrored by decreases in the RMSSD index, which reflects cardiac vagal modulation. These results support the view that the cBRS decrease associated with the upright posture is a byproduct of decreased cardiac vagal modulation, triggered by the arterial baroreflex in response to central hypovolemia. Conversely, the greater baroreflex contribution to cardiac control associated with upright posture may be explained, at least in part, by enhanced fluctuations of SAP, which elicit a more effective entrainment of HP fluctuations by the arterial baroreflex. These SAP fluctuations may result

The influence of oxazaphosphorines alkylating agents on autonomic nervous system activity in rat experimental cystitis model.

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Dobrek, Łukasz; Baranowska, Agnieszka; Thor, Piotr J

2013-01-01

HF) values, the VLF percentage change seems to be of special meaning. IF produced smaller autonomic disturbances, and gentler bladders histological abnormalities comparing to CP. However, similar to CP, VLF [%] relative augmentation together with LF [%] and HF [%] drop accompanied the global ANS activity decrease. Additionally, in the case of IF treatment, a slight trend of nLF increase with nHF decrease was noted, suggesting the possible functional rearrangement between sympathetic (nLF) and parasympathetic (nHF) tension. It seems possible that the vagal withdrawal and--as a consequence--sympathetic overactivity, reflected by VLF [%] enlargement and HF and LF [%] diminishing (as well as LF and HF values decrease), may be an evidence of impaired anti-inflammatory cholinergic pathway, aggravating bladder inflammatory lesions. To sum up, our study showed ANS impairment in both CP- and IF-evoked experimental HC that was reflected in HRV recordings. HRV study, thus, may be considered to be a diagnostic tool for CP/IF treated patients, estimating autonomic abnormalities, associated with the HC development risk and its clinical course.

Concurrent relations among cigarette smoking status, resting heart rate variability, and erectile response.

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Harte, Christopher B

2014-05-01

Heart rate variability (HRV) is a marker of sympathovagal balance; it has been implicated in erectile function and is also altered by tobacco use. Furthermore, smoking and erectile health are strongly related, given that smokers are at increased risk for erectile dysfunction. Few studies have explored the interrelationships between smoking, HRV, and erectile function concurrently. The aim of this study was to examine potential mechanisms underlying tobacco's effects on penile hemodynamics by exploring the mediating role of HRV. The sample comprised 119 men (smokers = 64; nonsmokers = 55) (mean age 28.90 years; standard deviation (SD) 11.68; range 18-58) selected from the control conditions of three previously published experiments. Participants were free from a history of cardiovascular disease, myocardial infarct, and/or cardiac/cardiovascular medication use. During a laboratory visit, self-report, anthropometric, cardiovascular, and electrocardiographic data were assessed, as well as sexual arousal responses elicited from viewing an erotic film. Objective sexual arousal indices (circumferential change via penile plethysmography), self-reported erectile function (per the erectile function domain score of the International Index of Erectile Function [IIEF-EF]), and time- (SD of beat-to-beat intervals) and frequency-domain parameters of HRV (ratio of low-frequency [LF] power to high-frequency [HF] power [LF/HF ratio]) were assessed. Being a current long-term cigarette smoker was associated with dysregulated sympathovagal balance (higher LF/HF ratios, indicative of sympathetic nervous system dominance), which in turn showed inverse relations with magnitude of erectile tumescence. HRV did not mediate relations between tobacco use and either IIEF-EF scores or resting penile circumference. Findings suggest that dysfunctional cardiac autonomic tone may be an underlying mechanism by which tobacco exerts its deleterious effects on erectile health. Further research

Psychological distress following marital separation interacts with a polymorphism in the serotonin transporter gene to predict cardiac vagal control in the laboratory.

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Hasselmo, Karen; Sbarra, David A; O'Connor, Mary-Frances; Moreno, Francisco A

2015-06-01

Marital separation is linked to negative mental and physical health; however, the strength of this link may vary across people. This study examined changes in respiratory sinus arrhythmia (RSA), used to assess cardiac vagal control, in recently separated adults (N = 79; M time since separation = 3.5 months). When reflecting on the separation, self-reported psychological distress following the separation interacted with a polymorphism in the serotonin transporter gene (5-HTTLPR) and a relevant single nucleotide polymorphism (SNP), rs25531, to predict RSA. Among people reporting emotional difficulties after the separation, those who were homozygous for the short allele had lower RSA levels while reflecting on their relationship than other genotypes. The findings, although limited by the relatively small sample size, are discussed in terms of how higher-sensitivity genotypes may interact with psychological responses to stress to alter physiology. © 2015 Society for Psychophysiological Research.

Assessment of Autonomic Function by Phase Rectification of RRInterval Histogram Analysis in Chagas Disease

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Olivassé Nasari Junior

2015-06-01

Full Text Available Background: In chronic Chagas disease (ChD, impairment of cardiac autonomic function bears prognostic implications. Phase‑rectification of RR-interval series isolates the sympathetic, acceleration phase (AC and parasympathetic, deceleration phase (DC influences on cardiac autonomic modulation. Objective: This study investigated heart rate variability (HRV as a function of RR-interval to assess autonomic function in healthy and ChD subjects. Methods: Control (n = 20 and ChD (n = 20 groups were studied. All underwent 60-min head-up tilt table test under ECG recording. Histogram of RR-interval series was calculated, with 100 ms class, ranging from 600–1100 ms. In each class, mean RR-intervals (MNN and root-mean-squared difference (RMSNN of consecutive normal RR-intervals that suited a particular class were calculated. Average of all RMSNN values in each class was analyzed as function of MNN, in the whole series (RMSNNT, and in AC (RMSNNAC and DC (RMSNNDC phases. Slopes of linear regression lines were compared between groups using Student t-test. Correlation coefficients were tested before comparisons. RMSNN was log-transformed. (α < 0.05. Results: Correlation coefficient was significant in all regressions (p < 0.05. In the control group, RMSNNT, RMSNNAC, and RMSNNDC significantly increased linearly with MNN (p < 0.05. In ChD, only RMSNNAC showed significant increase as a function of MNN, whereas RMSNNT and RMSNNDC did not. Conclusion: HRV increases in proportion with the RR-interval in healthy subjects. This behavior is lost in ChD, particularly in the DC phase, indicating cardiac vagal incompetence.

Cardiac Autonomic and Blood Pressure Responses to an Acute Bout of Kettlebell Exercise.

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Wong, Alexei; Nordvall, Michael; Walters-Edwards, Michelle; Lastova, Kevin; Francavillo, Gwendolyn; Summerfield, Liane; Sanchez-Gonzalez, Marcos

2017-10-07

Kettlebell (KB) training has become an extremely popular exercise program for improving both muscle strength and aerobic fitness. However, the cardiac autonomic modulation and blood pressure (BP) responses induced by an acute KB exercise session are currently unknown. Understanding the impact of this exercise modality on the post-exercise autonomic modulation and BP would facilitate appropriate exercise prescription in susceptible populations. The present study evaluated the effects of an acute session of KB exercise on heart rate variability (HRV) and BP responses in healthy individuals. Seventeen (M=10, F=7) healthy subjects completed either a KB or non-exercise control trial in randomized order. HRV and BP measurements were collected at baseline, 3, 10 and 30 min after each trial. There were significant increases (P < 0.01) in heart rate, markers of sympathetic activity (nLF) and sympathovagal balance (nLF/nHF) for 30 min after the trial KB trial, while no changes from baseline were observed after the control trial. There were also significant decreases (P < 0.01) in markers of vagal tone (RMMSD, nHF) for 30 min as well as (P < 0.01) systolic BP and diastolic BP at 10 and 30 min after the trial KB trial while no changes from baseline were observed after the control trial. Our findings indicate that KB exercise increases sympathovagal balance for 30 min post-intervention which is concurrent with an important hypotensive effect. Further research is warranted to evaluate the potential clinical application of KB training in populations that might benefit from post-exercise hypotension, such as hypertensives.

Anxiety, depression and autonomic nervous system dysfunction in hypertension.

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Bajkó, Zoltán; Szekeres, Csilla-Cecília; Kovács, Katalin Réka; Csapó, Krisztina; Molnár, Sándor; Soltész, Pál; Nyitrai, Erika; Magyar, Mária Tünde; Oláh, László; Bereczki, Dániel; Csiba, László

2012-06-15

This study examined the relationship between autonomic nervous system dysfunction, anxiety and depression in untreated hypertension. 86 newly diagnosed hypertensive patients and 98 healthy volunteers were included in the study. The psychological parameters were assessed with Spielberger State-Trait Anxiety Inventory and Beck Depression Inventory by a skilled psychologist. Autonomic parameters were examined during tilt table examination (10min lying position, 10min passive tilt). Heart rate variability (HRV) was calculated by autoregressive methods. Baroreflex sensitivity (BRS) was calculated by non-invasive sequence method from the recorded beat to beat blood pressure values and RR intervals. Significantly higher state (42.6±9.3 vs. 39.6±10.7 p=0.05) and trait (40.1±8.9 vs. 35.1±8.6, p<0.0001) anxiety scores were found in the hypertension group. There was no statistically significant difference in the depression level. LF-RRI (Low Frequency-RR interval) of HRV in passive tilt (377.3±430.6 vs. 494.1±547, p=0.049) and mean BRS slope (11.4±5.5 vs. 13.2±6.4, p=0.07) in lying position were lower in hypertensives. Trait anxiety score correlates significantly with sympatho/vagal balance (LF/HF-RRI) in passive tilt position (Spearman R=-0.286, p=0.01). Anxiety could play a more important role than depression in the development of hypertension. Altered autonomic control of the heart could be one of the pathophysiological links between hypertension and psychological factors. Copyright © 2012 Elsevier B.V. All rights reserved.

Circadian Disruptions of Heart Rate Variability among Weekly Consecutive-12-hour 2 Shift Workers in the Automobile Factory in Korea.

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Son, Mia; Sung, Juhon; Yum, Myunggul; Kong, Jung Ok; Lee, Hye Un; Kim, In A; Kim, Jung Yeon

2004-05-01

The objective of this study is to compare the circadian patterns of heart rate variability assessed by 24-hour ambulatory electrocardiographic (ECG) recordings during day shift and night shift among the workers in the 5 days-concecutive- 12-hour shift in an automobile factory in Korea. The study population consisted 300 workers, who were randomly selected among the 8700 total workers in one car factory. To analyse circadian variation, the 24-hour ECG recordings (Marquette) were measured during day shift (08: 00-20: 00 h) and night shift (20: 00-08: 00 h). Analysis was performed for all time and frequency domain measures of HRV. 233 workers completed taking 24-hour ECG recordings. This study shows that the 24 hourcircadian variation mainly follows work/sleep cycle rather than day/night cycle among shift workers. This study also shows that among the night shift, the circadian variation between work and sleep cycle decreased compared to the work/sleep cycle among day shift workers. All time and frequency domain parameters (except LF/HF ratio) show significantly different between work and sleep in the day shift and night shift. These changes in heart rate variability circadian rhythms reflect significant reductions in cardiac parasympathetic activity with the most marked reduction in normal vagal activity among the shift workers. Especially, it suggests the circadian rhytm has blunted among the night workers. The quantification of the circadian variation in HRV can be a surrogates of workers' potential health risk, as well as suggests possible mechanisms through which the shift works compromise workers' health.

Does Virtual Reality-based Kinect Dance Training Paradigm Improve Autonomic Nervous System Modulation in Individuals with Chronic Stroke?

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Sampaio, Luciana Maria Malosá; Subramaniam, Savitha; Arena, Ross; Bhatt, Tanvi

2016-10-01

Physical inactivity and low resting heart rate variability (HRV) are associated with an increased cardiovascular deconditioning, risk of secondary stroke and mortality. Aerobic dance is a multidimensional physical activity and recent research supports its application as a valid alternative cardiovascular training. Furthermore, technological advances have facilitated the emergence of new approaches for exercise training holding promise, especially those methods that integrate rehabilitation with virtual gaming. The purpose of this study was to evaluate cardiac autonomic modulation in individuals with chronic stroke post-training using a virtual reality - based aerobic dance training paradigm. Eleven community-dwelling individuals with hemiparetic stroke [61.7( ± 4.3) years] received a virtual reality-based dance paradigm for 6 weeks using the commercially available Kinect dance video game "Just Dance 3." The training was delivered in a high-intensity tapering method with the first two weeks consisting of 5 sessions/week, next two weeks of 3 sessions/week and last two weeks of 2 sessions/week, with a total of 20 sessions. Data obtained for HRV analysis pre- and post-intervention consists of HRV for ten minutes in (1) supine resting position; (2) quiet standing. High-frequency (HF) power measures as indicators of cardiac parasympathetic activity, low-frequency (LF) power of parasympathetic-sympathetic balance and LF/HF of sympatho-vagal balance were calculated. YMCA submaximal cycle Ergometer test was used to acquire VO 2 max pre- and post-intervention. Changes in physical activity during dance training were assessed using Omran HJ-321 Tri-Axis Pedometer. After training, participants demonstrated a significant improvement in autonomic modulation in the supine position, indicating an improvement in LF=48.4 ( ± 20.1) to 40.3 ( ± 8.0), p =0.03; HF=51.5 ( ± 19) to 59.7 ( ± 8), p = 0.02 and LF/HF=1.6 ( ± 1.9) to 0.8 ( ± 0.26), p =0.05]. Post-training the

An investigation of vago-regulatory and health-behavior accounts for increased inflammation in posttraumatic stress disorder.

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Dennis, Paul A; Weinberg, J Brice; Calhoun, Patrick S; Watkins, Lana L; Sherwood, Andrew; Dennis, Michelle F; Beckham, Jean C

2016-04-01

Posttraumatic stress disorder (PTSD) has been linked to chronic inflammation, a condition that poses a risk for cardiovascular disease. Attenuated vagal activity has been proposed as a potential mediator of PTSD and inflammation, although associated behavioral health risks-namely cigarette smoking and alcohol dependence-might also account for that link. Inflammation was quantified by fasting serum concentrations of C-reactive protein (CRP), tumor necrosis factor (TNF)-α, interleukin (IL)-10, and thymus- and activation-regulated chemokine (TARC)/CCL17 collected from 85 participants with PTSD and 82 without PTSD. Latent variable modeling was used to assess the relationship between PTSD symptom severity and inflammation along with potential mediators vagal activity (respiratory sinus arrhythmia; RSA), smoking status, and lifetime alcohol dependence. PTSD symptom severity was associated with increased inflammation (β=.18, p=.02). However, this association was reduced in models that adjusted for RSA, smoking status, and lifetime alcohol dependence. Independent mediation effects were deemed significant via bootstrapping analyses. Together, RSA, smoking status, and lifetime alcohol dependence accounted for 95% of the effect of PTSD symptom severity on inflammation. Although RSA accounted for a modest proportion of the association between posttraumatic stress and pro-inflammatory responses, behavioral factors-specifically cigarette smoking and alcohol dependence-proved to be larger mediators. The benefits of PTSD treatment may be enhanced by additional interventions aimed at modifying these health behaviors. Published by Elsevier Inc.

Vagal stimulation targets select populations of intrinsic cardiac neurons to control neurally induced atrial fibrillation.

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Salavatian, Siamak; Beaumont, Eric; Longpré, Jean-Philippe; Armour, J Andrew; Vinet, Alain; Jacquemet, Vincent; Shivkumar, Kalyanam; Ardell, Jeffrey L

2016-11-01

Mediastinal nerve stimulation (MNS) reproducibly evokes atrial fibrillation (AF) by excessive and heterogeneous activation of intrinsic cardiac (IC) neurons. This study evaluated whether preemptive vagus nerve stimulation (VNS) impacts MNS-induced evoked changes in IC neural network activity to thereby alter susceptibility to AF. IC neuronal activity in the right atrial ganglionated plexus was directly recorded in anesthetized canines (n = 8) using a linear microelectrode array concomitant with right atrial electrical activity in response to: 1) epicardial touch or great vessel occlusion vs. 2) stellate or vagal stimulation. From these stressors, post hoc analysis (based on the Skellam distribution) defined IC neurons so recorded as afferent, efferent, or convergent (afferent and efferent inputs) local circuit neurons (LCN). The capacity of right-sided MNS to modify IC activity in the induction of AF was determined before and after preemptive right (RCV)- vs. left (LCV)-sided VNS (15 Hz, 500 μs; 1.2× bradycardia threshold). Neuronal (n = 89) activity at baseline (0.11 ± 0.29 Hz) increased during MNS-induced AF (0.51 ± 1.30 Hz; P neuronal synchrony increased during neurally induced AF, a local neural network response mitigated by preemptive VNS. These antiarrhythmic effects persisted post-VNS for, on average, 26 min. In conclusion, VNS preferentially targets convergent LCNs and their interactive coherence to mitigate the potential for neurally induced AF. The antiarrhythmic properties imposed by VNS exhibit memory. Copyright © 2016 the American Physiological Society.

Atrial Fibrillation and Gastro-Oesophageal Reflux Disease - Controversies and Challenges.

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Floria, Mariana; Barboi, Oana; Rezus, Ciprian; Ambarus, Valentin; Cijevschi-Prelipcean, Cristina; Balan, Gheorghe; Drug, Vasile Liviu

2015-01-01

Atrial fibrillation and gastro-oesophageal reflux are common manifestations in daily practice. The atria and the oesophagus are closely located and have similar nerve innervations. Over the last years, it has been observed that atrial fibrillation development and reflux disease could be related. Atrial fibrillation occurrence could be due to vagal nerve overstimulation. This, in association with vagal nerve-mediated parasympathetic stimulation, has also been observed in patients with gastro-oesophageal reflux. These mechanisms, in addition to inflammation, seem to be implicated in the pathophysiology of both diseases. Despite these associations supported by clinical and experimental studies, this relationship is still considered controversial. This review summarizes critical data regarding the association of gastro-oesophageal reflux and atrial fibrillation as well as their clinical implications.

Improved Gender Recognition during Stepping Activity for Rehab Application Using the Combinatorial Fusion Approach of EMG and HRV

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Nor Aziyatul Izni Mohd Rosli

2017-03-01

Full Text Available Gender recognition is trivial for a physiotherapist, but it is considered a challenge for computers. The electromyography (EMG and heart rate variability (HRV were utilized in this work for gender recognition during exercise using a stepper. The relevant features were extracted and selected. The selected features were then fused to automatically predict gender recognition. However, the feature selection for gender classification became a challenge to ensure better accuracy. Thus, in this paper, a feature selection approach based on both the performance and the diversity between the two features from the rank-score characteristic (RSC function in a combinatorial fusion approach (CFA (Hsu et al. was employed. Then, the features from the selected feature sets were fused using a CFA. The results were then compared with other fusion techniques such as naive bayes (NB, decision tree (J48, k-nearest neighbor (KNN and support vector machine (SVM. Besides, the results were also compared with previous researches in gender recognition. The experimental results showed that the CFA was efficient and effective for feature selection. The fusion method was also able to improve the accuracy of the gender recognition rate. The CFA provides much better gender classification results which is 94.51% compared to Barani’s work (90.34%, Nazarloo’s work (92.50%, and other classifiers.

[Stress and autonomic dysregulation in patients with fibromyalgia syndrome].

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Friederich, H-C; Schellberg, D; Mueller, K; Bieber, C; Zipfel, S; Eich, W

2005-06-01

The aim of the present study was to evaluate to what extent the orthostatic dysregulation of FMS patients can be attributed primarily to reduced baroreceptor-mediated activation of the sympathetic nervous system and whether a hyporeactive sympathetic nervous system can also be confirmed for mental stress. A total of 28 patients with primary FMS were examined and compared with 15 healthy subjects. Diagnostic investigations of the autonomic nervous system were based on measuring HRV in frequency range and assessing spontaneous baroreflex sensitivity (sBRS) under mental stress and passive orthostatism. Both under orthostatic and mental stress FMS patients exhibited reduced activation of the sympathetic nervous system as measured by the spectral power of HRV in the low-frequency range and the mean arterial blood pressure or heart rate. The present study provided no indications for dysregulation of sBRS. The results obtained confirm the hypothesis of a hyporeactive stress system in FMS patients for both peripherally and centrally mediated stimulation of the sympathetic nervous system.

Bronchopulmonary C-fibers' IL1RI contributes to the prolonged apneic response to intra-atrial injection of capsaicin by prenatal nicotinic exposure in rat pups

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Zhao, Lei; Zhuang, Jianguo; Xu, Fadi, E-mail: fxu@lrri.org

2016-07-15

Prenatal nicotinic exposure (PNE) as a SIDS model reportedly sensitizes bronchopulmonary C-fibers (PCFs), contributing to the prolonged PCF-mediated apnea in rat pups, but the relevant mechanisms are not fully understood. Pulmonary IL-1β upregulated by cigarette smoke is known to stimulate or sensitize PCFs acting via IL-1 type I receptor (IL1RI) and inhibit inspiration frequency. Because of its upregulation observed in SIDS victims, we hypothesized that PNE increased pulmonary IL-1β release and IL1RI expression in pulmonary C-neurons via action on α7 nicotinic acetylcholine receptors (α7nAChR) to induce the prolonged PCF-mediated apnea. IL-1β in BALF and IL1RI in the nodose/jugular (N/J) ganglion and vagal pulmonary C-neurons retrogradely-traced were compared between Ctrl (saline) and PNE pups and among the vehicle-treated Ctrl and PNE and methyllycaconitine (a selective α7nAChR antagonist)-treated PNE pups. The effect of IL-1RI blockade (IL-1Ra) on the PCF-mediated apnea was also compared between Ctrl and PNE pups. PNE significantly elevated IL-1β in BALF and upregulated IL1RI gene and protein expression in N/J ganglia and gene in vagal pulmonary C-neurons. All of these responses were eliminated by pretreatment with blockade of α7nAChR. In addition, the prolonged PCF-mediated apnea in PNE pups was significantly shortened by right atrial bolus injection of IL-1Ra. We conclude that PNE enhances pulmonary IL-1β release and PCF IL1RI expression acting via α7nAChR in contributing to sensitization of PCFs and prolongation of the PCF-mediated apneic response. - Highlights: • PNE increased pulmonary IL-1β release and IL1R1 expression in the N/J ganglia. • PNE elevated IL1R1 mRNA in vagal pulmonary C-neurons. • Blockage of peripheral IL1R1 reduced the PNE-induced PCF sensitization. • PNE induced the changes in IL-1β and IL1R1 dependent on action of α7nAChR.

Multiscale time irreversibility of heart rate and blood pressure variability during orthostasis

International Nuclear Information System (INIS)

Chladekova, L; Czippelova, B; Turianikova, Z; Tonhajzerova, I; Calkovska, A; Javorka, M; Baumert, M

2012-01-01

Time irreversibility is a characteristic feature of non-equilibrium, complex systems such as the cardiovascular control mediated by the autonomic nervous system (ANS). Time irreversibility analysis of heart rate variability (HRV) and blood pressure variability (BPV) represents a new approach to assess cardiovascular regulatory mechanisms. The aim of this paper was to assess the changes in HRV and BPV irreversibility during the active orthostatic test (a balance of ANS shifted towards sympathetic predominance) in 28 healthy young subjects. We used three different time irreversibility indices—Porta’s, Guzik's and Ehler's indices (P%, G% and E, respectively) derived from data segments containing 1000 beat-to-beat intervals on four timescales. We observed an increase in the HRV and a decrease in the BPV irreversibility during standing compared to the supine position. The postural change in irreversibility was confirmed by surrogate data analysis. The differences were more evident in G% and E than P% and for higher scale factors. Statistical analysis showed a close relationship between G% and E. Contrary to this, the association between P% and G% and P% and E was not proven. We conclude that time irreversibility of beat-to-beat HRV and BPV is significantly altered during orthostasis, implicating involvement of the autonomous nervous system in its generation. (paper)

Caudal fourth ventricular administration of the AMPK activator 5-aminoimidazole-4-carboxamide-riboside regulates glucose and counterregulatory hormone profiles, dorsal vagal complex metabolosensory neuron function, and hypothalamic Fos expression.

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Ibrahim, Baher A; Tamrakar, Pratistha; Gujar, Amit D; Cherian, Ajeesh Koshy; Briski, Karen P

2013-09-01

This study investigated the hypothesis that estrogen controls hindbrain AMP-activated protein kinase (AMPK) activity and regulation of blood glucose, counterregulatory hormone secretion, and hypothalamic nerve cell transcriptional status. Dorsal vagal complex A2 noradrenergic neurons were laser microdissected from estradiol benzoate (E)- or oil (O)-implanted ovariectomized female rats after caudal fourth ventricular (CV4) delivery of the AMPK activator 5-aminoimidazole-4-carboxamide-riboside (AICAR), for Western blot analysis. E advanced AICAR-induced increases in A2 phospho-AMPK (pAMPK) expression and in blood glucose levels and was required for augmentation of Fos, estrogen receptor-α (ERα), monocarboxylate transporter-2, and glucose transporter-3 protein in A2 neurons and enhancement of corticosterone secretion by this treatment paradigm. CV4 AICAR also resulted in site-specific modifications in Fos immunolabeling of hypothalamic metabolic structures, including the paraventricular, ventromedial, and arcuate nuclei. The current studies demonstrate that estrogen regulates AMPK activation in caudal hindbrain A2 noradrenergic neurons during pharmacological replication of energy shortage in this area of the brain, and that this sensor is involved in neural regulation of glucostasis, in part, through control of corticosterone secretion. The data provide unique evidence that A2 neurons express both ERα and -β proteins and that AMPK upregulates cellular sensitivity to ERα-mediated signaling during simulated energy insufficiency. The results also imply that estrogen promotes glucose and lactate uptake by these cells under those conditions. Evidence for correlation between hindbrain AMPK and hypothalamic nerve cell genomic activation provides novel proof for functional connectivity between this hindbrain sensor and higher order metabolic brain loci while demonstrating a modulatory role for estrogen in this interaction. Copyright © 2013 Wiley Periodicals, Inc.

Initial Weekly HRV Response is Related to the Prospective Change in VO2max in Female Soccer Players.

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Esco, M R; Flatt, A A; Nakamura, F Y

2016-06-01

The aim of this study was to determine whether the early response in weekly measures of HRV, when derived from a smartphone application, were related to the eventual change in VO2max following an off-season training program in female soccer athletes. 9 female collegiate soccer players participated in an 11-week off-season conditioning program. In the week immediately before and after the training program, each participant performed a test on a treadmill to determine maximal oxygen consumption (VO2max). Daily measures of the log-transformed root mean square of successive R-R intervals (lnRMSSD) were performed by the participants throughout week 1 and week 3 of the conditioning program. The mean and coefficient of variation (CV) lnRMSSD values of week 1 showed small (r=- 0.13, p=0.74) and moderate (r=0.57, p=0.11), respectively, non-significant correlations to the change in VO2max at the end of the conditioning program (∆VO2max). Significant and near-perfect correlation was found between the change in the weekly mean lnRMSSD values from weeks 1 and 3 (∆lnRMSSDM) and ∆VO2max (r=0.90, p=0.002). The current results have identified that the initial change in weekly mean lnRMSSD from weeks 1 to 3 of a conditioning protocol was strongly associated with the eventual adaptation of VO2max. © Georg Thieme Verlag KG Stuttgart · New York.

CCK1-Receptor Stimulation Protects Against Gut Mediator-Induced Lung Damage During Endotoxemia

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Friederike Eisner

2013-12-01

Full Text Available Background/Aims: Cholecystokinin 1-receptor (CCK1-R activation by long chain fatty acid (LCFA absorption stimulates vago-vagal reflex pathways in the brain stem. The present study determines whether this reflex also activates the cholinergic anti-inflammatory pathway, a pathway known to modulate cytokine release during endotoxemia. Methods:Mesenteric lymph was obtained from wild type (WT and CCK1-R knockout (CCK1-R-/- mice intraperitoneally challenged with Lipopolysaccharid (LPS (endotoxemic lymph, EL and intestinally infused with vehicle or LCFA-enriched solution. The lymph was analyzed for TNFα, IL-6 and IL-10 concentration and administered to healthy recipient mice via jugular infusion. Alveolar wall thickness, myeloperoxidase (MPO and TUNEL positive cells were determined in lung tissue of recipient mice. Results: LCFA infusion in WT mice reduced TNFα concentration in EL by 49% compared to vehicle infusion, but had no effect in CCK1-R-/- mice. EL significantly increased the alveolar wall thickness, the number of MPO-positive and TUNEL-positive cells compared to control lymph administration. LCFA infusion in WT, but not in CCK1R-/- mice, significantly reduced these pathological effects of EL. Conclusion: During endotoxemia enteral LCFA absorption reduces TNFα release into mesenteric lymph and attenuates histomorphologic parameters of lung dysfunction. Failure to elicit this effect in CCK1R-/- mice demonstrates that anti-inflammatory properties of LCFAs are mediated through CCK1-Rs.

Effects of Some Indigenous Plants of North Karnataka (India) on Cardiovascular and Glucose Regulatory Systems in Alloxan-Induced Diabetic Rats.

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Das, Kusal K; Chadchan, Kailash S; Reddy, R Chandramouli; Biradar, M S; Kanthe, Pallavi S; Patil, Bheemshetty S; Ambekar, Jeevan G; Bagoji, Ishwar B; Das, Swastika

2017-11-08

Kenaf (Hibiscus cannabinus Linn, Pundi), Chick pea (Cicer arietinum Linn, Chana) and Prickly lettuce (Lactuca scariola Linn, Hattaraki) leaves are a few of indigenous plants which are routinely consumed by the people of north Karnataka in the diet. Studies on these plants showed some potential anti-diabetic efficacies. To examine the effect of leaves extracts of Hibiscus cannabinus Linn, Cicer arietinum Linn and Lactuca scariola Linn on cardiovascular integrity, glucose homeostasis and oxygen sensing cell signaling mechanisms in alloxan induced diabetic rats. In vitro and in vivo tests on glucose regulatory systems and molecular markers such as - NOS3, HIF- 1α and VEGF were conducted in alloxan induced diabetic rats supplemented with all the three plant extracts. Electrophysiological analysis (HRV, LF: HF ratio, baroreflex sensitivity, BRS) and histopathogy of myocardial tissues and elastic artery were evaluated in diabetic rats treated with L. scariola linn. Out of these three plant extracts, Lactuca scariola Linn supplementation showed significant beneficial effects on glucose homeostasis and oxygen sensing cell signaling pathways in alloxaninduced diabetic rats. Furthermore, effects of sub chronic supplementation of Lactuca scariola Linn aqueous extracts showed significant improvement in sympatho-vagal balance in diabetic rats by increase of Heart Rate Variability (HRV) and regaining of Baroreflex Sensitivity (BRS). These results were also corroborated with myocardial and elastic artery histopathology of Lactuca scariola Linn supplemented diabetic rats. These findings indicate an adaptive pathway for glucose homeostasis, oxygen sensing cell signaling mechanisms and cardio protective actions in alloxan - induced diabetic rats supplemented with Lactuca scariola Linn extracts. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Influence of hydrotherapy on clinical and cardiac autonomic function in migraine patients.

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Sujan, M U; Rao, M Raghavendra; Kisan, Ravikiran; Abhishekh, Hulegar A; Nalini, Atchayaram; Raju, Trichur R; Sathyaprabha, T N

2016-01-01

Migraine is associated with autonomic symptoms. The growing body of literature suggests that the dysfunctional autonomic nervous system might play a pivotal role in the pathogenesis of migraine. Thermal therapies have been hypothesized to modulate these changes and alleviate pain. However, data regarding the efficacy of hydrotherapy in migraine remain scant. We evaluated the effect of add on hydrotherapy procedure (a hot arm and foot bath with ice massage to head) in migraine patients. Forty chronic migraine patients fulfilling the International Classification of Headache Disorders II criteria were recruited from the neurology outpatient clinic. Patients were randomized to receive either hydrotherapy plus conventional pharmacological care (n = 20) or conventional medication only (n = 20). Hydrotherapy group received treatment with hot arm and foot bath (103°F to 110°F) and ice massage to head daily for 20 min for 45 days. Patients were assessed using headache impact test (HIT), visual analog scale for pain and cardiac autonomic function by heart rate variability (HRV) before and after intervention period. There was a significant decrease in HIT score, frequency, and intensity of headaches following treatment in both the groups. However, it was more evident in add on hydrotherapy group compared to pharmacological treatment alone group. There was also significant improvement in the HRV parameters. In particular, there was a significant decrease in heart rate (P = 0.017), increase in high frequency (HF) (P = 0.014) and decrease in low frequency/HF ratio (P = 0.004) in add on hydrotherapy group. Our study shows that add on hydrotherapy enhanced the vagal tone in addition to reducing the frequency and intensity of headaches in migraine patients.

Mediation Analysis with Multiple Mediators.

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VanderWeele, T J; Vansteelandt, S

2014-01-01

Recent advances in the causal inference literature on mediation have extended traditional approaches to direct and indirect effects to settings that allow for interactions and non-linearities. In this paper, these approaches from causal inference are further extended to settings in which multiple mediators may be of interest. Two analytic approaches, one based on regression and one based on weighting are proposed to estimate the effect mediated through multiple mediators and the effects through other pathways. The approaches proposed here accommodate exposure-mediator interactions and, to a certain extent, mediator-mediator interactions as well. The methods handle binary or continuous mediators and binary, continuous or count outcomes. When the mediators affect one another, the strategy of trying to assess direct and indirect effects one mediator at a time will in general fail; the approach given in this paper can still be used. A characterization is moreover given as to when the sum of the mediated effects for multiple mediators considered separately will be equal to the mediated effect of all of the mediators considered jointly. The approach proposed in this paper is robust to unmeasured common causes of two or more mediators.

Vagal stimulation targets select populations of intrinsic cardiac neurons to control neurally induced atrial fibrillation

Science.gov (United States)

Salavatian, Siamak; Beaumont, Eric; Longpré, Jean-Philippe; Armour, J. Andrew; Vinet, Alain; Jacquemet, Vincent; Shivkumar, Kalyanam

2016-01-01

Mediastinal nerve stimulation (MNS) reproducibly evokes atrial fibrillation (AF) by excessive and heterogeneous activation of intrinsic cardiac (IC) neurons. This study evaluated whether preemptive vagus nerve stimulation (VNS) impacts MNS-induced evoked changes in IC neural network activity to thereby alter susceptibility to AF. IC neuronal activity in the right atrial ganglionated plexus was directly recorded in anesthetized canines (n = 8) using a linear microelectrode array concomitant with right atrial electrical activity in response to: 1) epicardial touch or great vessel occlusion vs. 2) stellate or vagal stimulation. From these stressors, post hoc analysis (based on the Skellam distribution) defined IC neurons so recorded as afferent, efferent, or convergent (afferent and efferent inputs) local circuit neurons (LCN). The capacity of right-sided MNS to modify IC activity in the induction of AF was determined before and after preemptive right (RCV)- vs. left (LCV)-sided VNS (15 Hz, 500 μs; 1.2× bradycardia threshold). Neuronal (n = 89) activity at baseline (0.11 ± 0.29 Hz) increased during MNS-induced AF (0.51 ± 1.30 Hz; P < 0.001). Convergent LCNs were preferentially activated by MNS. Preemptive RCV reduced MNS-induced changes in LCN activity (by 70%) while mitigating MNS-induced AF (by 75%). Preemptive LCV reduced LCN activity by 60% while mitigating AF potential by 40%. IC neuronal synchrony increased during neurally induced AF, a local neural network response mitigated by preemptive VNS. These antiarrhythmic effects persisted post-VNS for, on average, 26 min. In conclusion, VNS preferentially targets convergent LCNs and their interactive coherence to mitigate the potential for neurally induced AF. The antiarrhythmic properties imposed by VNS exhibit memory. PMID:27591222

In vitro research of the alteration of neurons in vagal core in medulla oblongata at asphyxic deaths.

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Haliti, Naim; Islami, Hilmi; Elezi, Nevzat; Shabani, Ragip; Abdullahu, Bedri; Dragusha, Gani

2010-08-01

The aim of this study was to research the morphological changes of neurons in the vagus nerve nuclei in medulla oblongata in asphyxia related death cases. Morphological changes that were investigated were mainly in the dorsal motor respiratory center (DMRC), nucleus tractus solitarius (nTS) and nucleus ambigus (nA) in the medulla oblongata. In our research, the autopsy material from asphyxia related death cases was used from various etiologies: monoxide carbon (CO), liquid drowning, strangulation, electricity, clinical-pathological death, firing weapon, explosive weapon, sharp and blunt objects and death cases due to accident. The material selected for research was taken from medulla oblongata and lungs from all lobes. The material from the medulla oblongata and lungs was fixed in a 10% solution of buffered formalin. Special histochemical methods for central nervous system (CNS) were employed like: Cresyl echt violet, toluidin blue, Sevier-Munger modification and Grimelius. For stereometrical analysis of the quantitative density of the neurons the universal testing system Weibel M42 was used. The acquired results show that in sudden asphyxia related death cases, there are alterations in the nuclei of vagal nerve in form of: central chromatolysis, axonal retraction, axonal fragmentation, intranuclear vacuolization, cytoplasmic vacuolization, edema, condensation and dispersion of substance of Nissl, proliferation of oligodendrocytes, astrocytes and microglia. The altered population of vagus nerve neurons does not show an important statistical significance compared to the overall quantity of the neurons in the nuclei of the vagus nerve (p<0.05).

Radiofrequency Catheter Ablation for Atrial Fibrillation Elicited "Jackhammer Esophagus": A New Complication Due to Vagal Nerve Stimulation?

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Tolone, Salvatore; Savarino, Edoardo; Docimo, Ludovico

2015-10-01

Radiofrequency catheter ablation (RFCA) is a potentially curative method for treatment of highly symptomatic and drug-refractory atrial fibrillation (AF). However, this technique can provoke esophageal and nerve lesion, due to thermal injury. To our knowledge, there have been no reported cases of a newly described motor disorder, the Jackhammer esophagus (JE) after RFCA, independently of GERD. We report a case of JE diagnosed by high-resolution manometry (HRM), in whom esophageal symptoms developed 2 weeks after RFCA, in absence of objective evidence of GERD. A 65-year-old male with highly symptomatic, drug-refractory paroxysmal AF was candidate to complete electrical pulmonary vein isolation with RFCA. Prior the procedure, the patient underwent HRM and impedance-pH to rule out GERD or hiatal hernia presence. All HRM parameters, according to Chicago classification, were within normal limits. No significant gastroesophageal reflux was documented at impedance pH monitoring. Patient underwent RFCA with electrical disconnection of pulmonary vein. After two weeks, patient started to complain of dysphagia for solids, with acute chest-pain. The patient repeated HRM and impedance-pH monitoring 8 weeks after RFCA. HRM showed in all liquid swallows the typical spastic hypercontractile contractions consistent with the diagnosis of JE, whereas impedance-pH monitoring resulted again negative for GERD. Esophageal dysmotility can represent a possible complication of RFCA for AF, probably due to a vagal nerve injury, and dysphagia appearance after this procedure must be timely investigated by HRM.

Afferent nerves regulating the cough reflex: Mechanisms and Mediators of Cough in Disease

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Canning, Brendan J.

2010-01-01

Bronchopulmonary C-fibers and acid-sensitive, capsaicin-insensitive mechanoreceptors innervating the larynx, trachea and large bronchi regulate the cough reflex. These vagal afferent nerves may interact centrally with sensory input arising from afferent nerves innervating the intrapulmonary airways or even extrapulmonary afferents such as those innervating the nasal mucosa and esophagus to produce chronic cough or enhanced cough responsiveness. The mechanisms of cough initiation in health and in disease are briefly described. PMID:20172253

Sympatho-vagal responses in patients with sleep and typical vasovagal syncope

NARCIS (Netherlands)

Jardine, D. L.; Krediet, C. T. P.; Cortelli, P.; Frampton, C. M.; Wieling, W.

2009-01-01

Sleep syncope is a recently described form of vasovagal syncope that interrupts sleep. The pathophysiology of this condition is uncertain but a 'central' non-baroreflex-mediated trigger has been suggested. In the present study, we tested the hypothesis that patients with sleep syncope have abnormal

Sustained Weight Loss with Vagal Nerve Blockade but Not with Sham: 18-Month Results of the ReCharge Trial

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Scott A. Shikora

2015-01-01

Full Text Available Background/Objectives. Vagal block therapy (vBloc is effective for moderate to severe obesity at one year. Subjects/Methods. The ReCharge trial is a double-blind, randomized controlled clinical trial of 239 participants with body mass index (BMI of 40 to 45 kg/m or 35 to 40 kg/m with one or more obesity-related conditions. Interventions were implantation of either vBloc or Sham devices and weight management counseling. Mixed models assessed percent excess weight loss (%EWL and total weight loss (%TWL in intent-to-treat analyses. At 18 months, 142 (88% vBloc and 64 (83% Sham patients remained enrolled in the study. Results. 18-month weight loss was 23% EWL (8.8% TWL for vBloc and 10% EWL (3.8% TWL for Sham (P<0.0001. vBloc patients largely maintained 12-month weight loss of 26% EWL (9.7% TWL. Sham regained over 40% of the 17% EWL (6.4% TWL by 18 months. Most weight regain preceded unblinding. Common adverse events of vBloc through 18 months were heartburn/dyspepsia and abdominal pain; 98% of events were reported as mild or moderate and 79% had resolved. Conclusions. Weight loss with vBloc was sustained through 18 months, while Sham regained weight between 12 and 18 months. vBloc is effective with a low rate of serious complications.

Selective Enhancement of Synaptic Inhibition by Hypocretin (Orexin) in Rat Vagal Motor Neurons: Implications for Autonomic Regulation

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Davis, Scott F.; Williams, Kevin W.; Xu, Weiye; Glatzer, Nicholas R.; Smith, Bret N.

2012-01-01

The hypocretins (orexins) are hypothalamic neuropeptides implicated in feeding, arousal, and autonomic regulation. These studies were designed to determine the actions of hypocretin peptides on synaptic transmission in the dorsal motor nucleus of the vagus nerve (DMV). Whole-cell patch-clamp recordings were made from DMV neurons in transverse slices of rat brainstem. Some of the neurons were identified as gastric-related by retrograde labeling after inoculation of the stomach wall with pseudorabies virus 152, a viral label that reports enhanced green fluorescent protein. Consistent with previous findings, hypocretins caused an inward current (6–68 pA) in most neurons at holding potentials near rest. In addition, the frequency of spontaneous IPSCs was increased in a concentration-related manner (up to 477%), with little change in EPSCs. This effect was preserved in the presence of tetrodotoxin, suggesting a presynaptic site of action. Hypocretins increased the amplitude of IPSCs evoked by electrical stimulation of the nucleus tractus solitarius (NTS) but not evoked EPSCs. Hypocretin-induced increases in the frequency of IPSCs evoked by photoactivation of caged glutamate within the NTS were also observed. Identical effects of the peptides were observed in identified gastric-related and unlabeled DMV neurons. In contrast to some previous studies, which have reported primarily excitatory actions of the hypocretins in many regions of the CNS, these data support a role for hypocretin in preferentially enhancing synaptic inhibition, including inhibitory inputs arising from neurons in the NTS. These findings indicate that the hypocretins can modulate and coordinate visceral autonomic output by acting directly on central vagal circuits. PMID:12736355

In Vitro Research of the Alteration of Neurons in Vagal Core in Medulla Oblongata at Asphyxic Deaths

Directory of Open Access Journals (Sweden)

Naim Haliti

2010-08-01

Full Text Available The aim of this study was to research the morphological changes of neurons in the vagus nerve nuclei in medulla oblongata in asphyxia related death cases. Morphological changes that were investigated were mainly in the dorsal motor respiratory center (DMRC, nucleus tractus solitarius (nTS and nucleus ambigus (nA in the medulla oblongata. In our research, the autopsy material from asphyxia related death cases was used from various etiologies: monoxide carbon (CO, liquid drowning, strangulation, electricity, clinical-pathological death, firing weapon, explosive weapon, sharp and blunt objects and death cases due to accident. The material selected for research was taken from medulla oblongata and lungs from all lobes. The material from the medulla oblongata and lungs was fixed in a 10% solution of buffered formalin. Special histochemical methods for central nervous system (CNS were employed like: Cresyl echt violet, toluidin blue, Sevier-Munger modification and Grimelius. For stereometrical analysis of the quantitative density of the neurons the universal testing system Weibel M42 was used. The acquired results show that in sudden asphyxia related death cases, there are alterations in the nuclei of vagal nerve in form of: central chromatolysis, axonal retraction, axonal fragmentation, intranuclear vacuolization, cytoplasmic vacuolization, edema, condensation and dispersion of substance of Nissl, proliferation of oligodendrocytes, astrocytes and microglia. The altered population of vagus nerve neurons does not show an important statistica! significarne compared to the overall quantity of the neurons in the nuclei of the vagus nerve (p<0,05.

Cycling cadence affects heart rate variability

International Nuclear Information System (INIS)

Lunt, Heather C; Corbett, Jo; Barwood, Martin J; Tipton, Michael J

2011-01-01

The purpose of this study was to examine the effect different cycling cadences have on heart rate variability (HRV) when exercising at constant power outputs. Sixteen males had ECG and respiratory measurements recorded at rest and during 8, 10 min periods of cycling at four different cadences (40, 60, 80 and 100 revs min −1 ) and two power outputs (0 W (unloaded) and 100 W (loaded)). The cycling periods were performed following a Latin square design. Spectral analyses of R–R intervals by fast Fourier transforms were used to quantify absolute frequency domain HRV indices (ms 2 ) during the final 5 min of each bout, which were then log transformed using the natural logarithm (Ln). HRV indices of high frequency (HF) power were reduced when cadence was increased (during unloaded cycling (0 W) log transformed HF power decreased from a mean [SD] of 6.3 [1.4] Ln ms 2 at 40 revs min −1 to 3.9 [1.3] Ln ms 2 at 100 revs min −1 ). During loaded cycling (at 100 W), the low to high frequency (LF:HF) ratio formed a 'J' shaped curve as cadence increased from 40 revs min −1 (1.4 [0.4]) to 100 revs min −1 (1.9 [0.7]), but dipped below the 40 revs min −1 values during the 60 revs min −1 1.1 (0.3) and 80 revs min −1 1.2 (0.6) cadence conditions. Cardiac frequency (f C ) and ventilatory variables were strongly correlated with frequency domain HRV indices (r = −0.80 to −0.95). It is concluded that HRV indices are influenced by both cycling cadence and power output; this is mediated by the f C and ventilatory changes that occur as cadence or exercise intensity is increased. Consequently, if HRV is assessed during exercise, both power output/exercise intensity and cadence should be standardized

Prenatal vitamin A deficiency impairs adaptive immune responses to pentavalent rotavirus vaccine (RotaTeq®) in a neonatal gnotobiotic pig model.

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Kandasamy, Sukumar; Chattha, Kuldeep S; Vlasova, Anastasia N; Saif, Linda J

2014-02-07

Vitamin A deficiency (VAD) is associated with increased childhood mortality and morbidity in impoverished Asian and African countries, but the impact of VAD on rotavirus (RV) vaccine or infection is poorly understood. We assessed effects of gestational and dietary induced pre- and post-natal VAD and vitamin A supplementation on immune responses to a pentavalent rotavirus vaccine, RotaTeq(®) in a neonatal gnotobiotic pig model. Vaccine efficacy was assessed against virulent G1P[8] human rotavirus (HRV) challenge. VAD and vitamin A sufficient (VAS) piglets were derived from dietary VAD and VAS sows, respectively. VAD piglets had significantly lower levels of hepatic vitamin A compared to that of VAS piglets. RotaTeq(®)-vaccinated VAD piglets had 350-fold higher fecal virus shedding titers compared to vaccinated VAS piglets post-challenge. Only 25% of vaccinated non-vitamin A supplemented VAD piglets were protected against diarrhea compared with 100% protection rate in vaccinated non-supplemented VAS piglets post-challenge. Intestinal HRV specific immune responses were compromised in VAD piglets. Vaccinated VAD piglets had significantly lower ileal HRV IgG antibody secreting cell (ASC) responses (pre-challenge) and duodenal HRV IgA ASC responses (post-challenge) compared to vaccinated VAS piglets. Also, intestinal HRV IgA antibody titers were 11-fold lower in vaccinated VAD compared to vaccinated VAS piglets post-challenge. Persistently elevated levels of IL-8, a pro-inflammatory mediator, and lower IL-10 responses (anti-inflammatory) in vaccinated VAD compared to VAS piglets suggest more severe inflammatory responses in VAD piglets post-challenge. Moreover higher IFN-γ responses pre-challenge were observed in VAD compared to VAS piglets. The impaired vaccine-specific intestinal antibody responses and decreased immunoregulatory cytokine responses coincided with reduced protective efficacy of the RV vaccine against virulent HRV challenge in VAD piglets. In

Glutamate Receptors in the Central Nucleus of the Amygdala Mediate Cisplatin-Induced Malaise and Energy Balance Dysregulation through Direct Hindbrain Projections.

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Alhadeff, Amber L; Holland, Ruby A; Nelson, Alexandra; Grill, Harvey J; De Jonghe, Bart C

2015-08-05

Cisplatin chemotherapy is used commonly to treat a variety of cancers despite severe side effects such as nausea, vomiting, and anorexia that compromise quality of life and limit treatment adherence. The neural mechanisms mediating these side effects remain elusive despite decades of clinical use. Recent data highlight the dorsal vagal complex (DVC), lateral parabrachial nucleus (lPBN), and central nucleus of the amygdala (CeA) as potential sites of action in mediating the side effects of cisplatin. Here, results from immunohistochemical studies in rats identified a population of cisplatin-activated DVC neurons that project to the lPBN and a population of cisplatin-activated lPBN calcitonin gene-related peptide (CGRP, a marker for glutamatergic neurons in the lPBN) neurons that project to the CeA, outlining a neuroanatomical circuit that is activated by cisplatin. CeA gene expressions of AMPA and NMDA glutamate receptor subunits were markedly increased after cisplatin treatment, suggesting that CeA glutamate receptor signaling plays a role in mediating cisplatin side effects. Consistent with gene expression results, behavioral/pharmacological data showed that CeA AMPA/kainate receptor blockade attenuates cisplatin-induced pica (a proxy for nausea/behavioral malaise in nonvomiting laboratory rodents) and that CeA NMDA receptor blockade attenuates cisplatin-induced anorexia and body weight loss in addition to pica, demonstrating that glutamate receptor signaling in the CeA is critical for the energy balance dysregulation caused by cisplatin treatment. Together, these data highlight a novel circuit and CGRP/glutamatergic mechanism through which cisplatin-induced malaise and energy balance dysregulation are mediated. To treat cancer effectively, patients must follow prescribed chemotherapy treatments without interruption, yet most cancer treatments produce side effects that devastate quality of life (e.g., nausea, vomiting, anorexia, weight loss). Although hundreds of

Glutamate Receptors in the Central Nucleus of the Amygdala Mediate Cisplatin-Induced Malaise and Energy Balance Dysregulation through Direct Hindbrain Projections

Science.gov (United States)

Alhadeff, Amber L.; Holland, Ruby A.; Nelson, Alexandra; Grill, Harvey J.

2015-01-01

Cisplatin chemotherapy is used commonly to treat a variety of cancers despite severe side effects such as nausea, vomiting, and anorexia that compromise quality of life and limit treatment adherence. The neural mechanisms mediating these side effects remain elusive despite decades of clinical use. Recent data highlight the dorsal vagal complex (DVC), lateral parabrachial nucleus (lPBN), and central nucleus of the amygdala (CeA) as potential sites of action in mediating the side effects of cisplatin. Here, results from immunohistochemical studies in rats identified a population of cisplatin-activated DVC neurons that project to the lPBN and a population of cisplatin-activated lPBN calcitonin gene-related peptide (CGRP, a marker for glutamatergic neurons in the lPBN) neurons that project to the CeA, outlining a neuroanatomical circuit that is activated by cisplatin. CeA gene expressions of AMPA and NMDA glutamate receptor subunits were markedly increased after cisplatin treatment, suggesting that CeA glutamate receptor signaling plays a role in mediating cisplatin side effects. Consistent with gene expression results, behavioral/pharmacological data showed that CeA AMPA/kainate receptor blockade attenuates cisplatin-induced pica (a proxy for nausea/behavioral malaise in nonvomiting laboratory rodents) and that CeA NMDA receptor blockade attenuates cisplatin-induced anorexia and body weight loss in addition to pica, demonstrating that glutamate receptor signaling in the CeA is critical for the energy balance dysregulation caused by cisplatin treatment. Together, these data highlight a novel circuit and CGRP/glutamatergic mechanism through which cisplatin-induced malaise and energy balance dysregulation are mediated. SIGNIFICANCE STATEMENT To treat cancer effectively, patients must follow prescribed chemotherapy treatments without interruption, yet most cancer treatments produce side effects that devastate quality of life (e.g., nausea, vomiting, anorexia, weight loss

Prevalence of human rhinovirus in children admitted to hospital with acute lower respiratory tract infections in Changsha, China.

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Zeng, Sai-Zhen; Xiao, Ni-Guang; Xie, Zhi-Ping; Xie, Guang-Cheng; Zhong, Li-Li; Wang, Juan; Huang, Han; Zhang, Bing; Duan, Zhao-Jun

2014-11-01

Human rhinovirus (HRV) is a causative agent of acute respiratory tract infections. This study analyzed the prevalence and clinical characteristics of three HRV groups (HRV-A, -B, and -C) among 1,165 children aged 14 years or younger who were hospitalized with acute lower respiratory tract infection in China. PCR or reverse transcription-PCR was performed to detect 14 respiratory viruses in nasopharyngeal aspirates collected from September 2007 to August 2008 in Changsha, China. HRV was detected in 202 (17.3%) of the 1,165 children; 25.3% of the HRV-positive children were 13-36 months of age (χ(2)  = 22.803, P = 0.000). HRV was detected year round and peaked between September and December. Fifty-three percent of the HRV-positive samples were also positive for other respiratory viruses; respiratory syncytial virus (RSV) was the most common secondary virus. Phylogenetic analysis using the VP4/VP2 region grouped the HRV-positive strains as follows: 101 HRV-A (50.0%), 21 HRV-B (10.4%), and 80 HRV-C (39.6%). HRV-A infections occurred predominantly in spring and autumn, and the peak prevalence of HRV-C was in early winter and late autumn. HRV-B infections were less common in spring (χ(2)  = 31.914, P = 0.000). No significant difference in clinical severity or presentation was found between patients with HRV single infection and HRV co-detections. Furthermore, the clinical characterizations did not differ among the three HRV species. These results suggest that HRV-C is an important viral agent along with HRV-A and HRV-B and that among hospitalized children with acute lower respiratory tract infection in China, the three HRV genotypes have similar clinical characteristics. © 2014 Wiley Periodicals, Inc.

Vagotomy attenuates brain cytokines and sleep induced by peripherally administered tumor necrosis factor-α and lipopolysaccharide in mice.

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Zielinski, Mark R; Dunbrasky, Danielle L; Taishi, Ping; Souza, Gianne; Krueger, James M

2013-08-01

Systemic tumor necrosis factor-α (TNF-α) is linked to sleep and sleep altering pathologies in humans. Evidence from animals indicates that systemic and brain TNF-α have a role in regulating sleep. In animals, TNF-α or lipopolysaccharide (LPS) enhance brain pro-inflammatory cytokine expression and sleep after central or peripheral administration. Vagotomy blocks enhanced sleep induced by systemic TNF-α and LPS in rats, suggesting that vagal afferent stimulation by TNF-α enhances pro-inflammatory cytokines in sleep-related brain areas. However, the effects of systemic TNF-α on brain cytokine expression and mouse sleep remain unknown. We investigated the role of vagal afferents on brain cytokines and sleep after systemically applied TNF-α or LPS in mice. Spontaneous sleep was similar in vagotomized and sham-operated controls. Vagotomy attenuated TNF-α- and LPS-enhanced non-rapid eye movement sleep (NREMS); these effects were more evident after lower doses of these substances. Vagotomy did not affect rapid eye movement sleep responses to these substances. NREMS electroencephalogram delta power (0.5-4 Hz range) was suppressed after peripheral TNF-α or LPS injections, although vagotomy did not affect these responses. Compared to sham-operated controls, vagotomy did not affect liver cytokines. However, vagotomy attenuated interleukin-1 beta (IL-1β) and TNF-α mRNA brain levels after TNF-α, but not after LPS, compared to the sham-operated controls. We conclude that vagal afferents mediate peripheral TNF-α-induced brain TNF-α and IL-1β mRNA expressions to affect sleep. We also conclude that vagal afferents alter sleep induced by peripheral pro-inflammatory stimuli in mice similar to those occurring in other species.

Modulation of cardiopulmonary depressor reflex in nucleus ambiguus by electroacupuncture: roles of opioids and γ-aminobutyric acid.

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Tjen-A-Looi, Stephanie C; Li, Peng; Li, Min; Longhurst, John C

2012-04-01

Stimulation of cardiopulmonary receptors with phenylbiguanide (PBG) elicits depressor cardiovascular reflex responses, including decreases in blood pressure and heart rate mediated in part by the brain stem parasympathetic cardiac neurons in the nucleus ambiguus (NAmb). The present study examined NAmb neurotransmitter mechanisms underlying the influence of electroacupuncture (EA) on the PBG-induced hypotension and bradycardia. We hypothesized that somatic stimulation during EA modulates PBG responses through opioid and γ-aminobutyric acid (GABA) modulation in the NAmb. Anesthetized and ventilated cats were studied during repeated stimulation with PBG or cardiac vagal afferents while low-frequency EA (2 Hz) was applied at P5-6 acupoints overlying the median nerve for 30 min and NAmb neuronal activity, heart rate, and blood pressure were recorded. Microinjection of kainic acid into the NAmb attenuated the PBG-induced bradycardia from -60 ± 11 to -36 ± 11 beats/min. Likewise, EA reduced the PBG-induced depressor and bradycardia reflex by 52 and 61%, respectively. Cardiac vagal afferent evoked preganglionic cellular activity in the NAmb was reduced by EA for about 60 min. Blockade of opioid or GABA(A) receptors using naloxone and gabazine reversed the EA-related modulation of the evoked cardiac vagal activity by 73 and 53%, respectively. Similarly, naloxone and gabazine reversed EA modulation of the negative chronotropic responses from -11 ± 5 to -23 ± 6 and -13 ± 4 to -24 ± 3 beats/min, respectively. Thus EA at P5-6 decreases PBG evoked hypotension and bradycardia as well as the NAmb PBG-sensitive preganglionic cardiac vagal outflow through opioid and GABA neurotransmitter systems.

GABA in nucleus tractus solitarius participates in electroacupuncture modulation of cardiopulmonary bradycardia reflex.

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Tjen-A-Looi, Stephanie C; Guo, Zhi-Ling; Longhurst, John C

2014-12-01

Phenylbiguanide (PBG) stimulates cardiopulmonary receptors and cardiovascular reflex responses, including decreases in blood pressure and heart rate mediated by the brain stem parasympathetic cardiac neurons in the nucleus ambiguus and nucleus tractus solitarius (NTS). Electroacupuncture (EA) at P5-6 stimulates sensory fibers in the median nerve and modulates these reflex responses. Stimulation of median nerves reverses bradycardia through action of γ-aminobutyric acid (GABA) in the nucleus ambiguus, important in the regulation of heart rate. We do not know whether the NTS or the neurotransmitter mechanisms in this nucleus participate in these modulatory actions by acupuncture. We hypothesized that somatic nerve stimulation during EA (P5-6) modulates cardiopulmonary inhibitory responses through a GABAergic mechanism in the NTS. Anesthetized and ventilated cats were examined during either PBG or direct vagal afferent stimulation while 30 min of EA was applied at P5-6. Reflex heart rate and blood pressure responses and NTS-evoked discharge were recorded. EA reduced the PBG-induced depressor and bradycardia reflexes by 67% and 60%, respectively. Blockade of GABAA receptors in the NTS reversed EA modulation of bradycardia but not the depressor response. During EA, gabazine reversed the vagally evoked discharge activity of cardiovascular NTS neurons. EA modulated the vagal-evoked cardiovascular NTS cellular activity for 60 min. Immunohistochemistry using triple labeling showed GABA immunoreactive fibers juxtaposed to glutamatergic nucleus ambiguus-projecting NTS neurons in rats. These glutamatergic neurons expressed GABAA receptors. These findings suggest that EA inhibits PBG-evoked bradycardia and vagally evoked NTS activity through a GABAergic mechanism, likely involving glutamatergic nucleus ambiguus-projecting NTS neurons. Copyright © 2014 the American Physiological Society.

Cardiac autonomic modulation during progressive upper limb exercise by patients with coronary artery disease

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H.G. Machado

2011-12-01

Full Text Available The purpose of this study was to investigate the behavior of heart rate (HR and HR variability (HRV during different loads of resistance exercise (incline bench press in patients with coronary artery disease (CAD and healthy sedentary controls. Ten healthy men (65 ± 1.2 years, control group, CG and 10 men with clinically stable CAD (66 ± 2.4 years, CADG were recruited. A discontinuous progressive protocol was applied with an initial load of 10% of the maximum load achieved in the 1RM (1 repetition maximum with increases of 10% until 30% 1RM was reached, which was followed by subsequent increases of 5% 1RM until exhaustion. HRV was analyzed by linear and non-linear methods. There was a significant reduction in rMSSD (CG: 20 ± 2 to 11 ± 3 ms; CADG: 19 ± 3 to 9 ± 1 ms and SD1 indexes (CG: 14 ± 2 to 8 ± 1 ms; CADG: 14 ± 2 to 7 ± 1 ms. An increase in HR (CG: 69 ± 5 to 90 ± 5 bpm; CADG: 62 ± 4 to 75 ± 4 bpm and in systolic blood pressure (CG: 124 ± 3 to 138 ± 3 mmHg; CADG: 122 ± 6 to 126 ± 9 bpm were observed (P < 0.05 when comparing pre-effort rest and 40% 1RM in both groups. Furthermore, an increase in RMSM index was also observed (CG: 28 ± 3 to 45 ± 9 ms; CADG: 22 ± 2 to 79 ± 33 ms, with higher values in CADG. We conclude that loads up to 30% 1RM during incline bench press result in depressed vagal modulation in both groups, although only stable CAD patients presented sympathetic overactivity at 20% 1RM upper limb exercise.

Differential cardiac effects of aerobic interval training versus moderate continuous training in a patient with schizophrenia: a case report.

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Marco eHerbsleb

2014-08-01

Full Text Available Increased cardiovascular morbidity and mortality rates for patients with schizophrenia are reported to contribute to their reduced life expectancy. Common reasons for increased cardiac mortality rates include cigarette smoking, obesity, dyslipidemia, diabetes and poorer health behavior in general. The majority of excess mortality among people with schizophrenia is caused by cardiovascular complications. Reduced vagal activity might be one important mechanism leading to this increased cardiac mortality and has been consistently described in patients and their healthy first-degree relatives.In this case study, we compared two different aerobic exercise regimes in one patient with chronic schizophrenia to investigate their effects on cardiovascular regulation. The patient completed a 6-week period of moderate continuous training followed by a 6-week period of interval training, each regime 2 times per week, on a stationary bicycle. This was followed by a 6-week period of detraining. Primary outcome measures examined heart rate (HR and heart rate variability (HRV at rest while secondary measures assessed fitness parameters such as the ventilatory threshold 1 (VT1. We observed that interval training was far more effective than moderate continuous training in increasing HRV, as indicated by RMSSD (improvement to baseline 27% vs. 18%, and reducing resting heart rate (-14% vs. 0%. Improvement in VT1 (21% vs. -1% was only observed after interval training. Our study provides preliminary data that the type of intervention is highly influential for improving cardiac function in patients with schizophrenia. While cardiovascular function might be influenced by continuous training to some degree, no such effect was present in this patient with schizophrenia. In addition, the beneficial effect of interval training on heart rate regulation vanished completely after a very short period of detraining after the intervention.

Influence of hydrotherapy on clinical and cardiac autonomic function in migraine patients

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M U Sujan

2016-01-01

Full Text Available Background: Migraine is associated with autonomic symptoms. The growing body of literature suggests that the dysfunctional autonomic nervous system might play a pivotal role in the pathogenesis of migraine. Thermal therapies have been hypothesized to modulate these changes and alleviate pain. However, data regarding the efficacy of hydrotherapy in migraine remain scant. We evaluated the effect of add on hydrotherapy procedure (a hot arm and foot bath with ice massage to head in migraine patients. Methods: Forty chronic migraine patients fulfilling the International Classification of Headache Disorders II criteria were recruited from the neurology outpatient clinic. Patients were randomized to receive either hydrotherapy plus conventional pharmacological care (n = 20 or conventional medication only (n = 20. Hydrotherapy group received treatment with hot arm and foot bath (103°F to 110°F and ice massage to head daily for 20 min for 45 days. Patients were assessed using headache impact test (HIT, visual analog scale for pain and cardiac autonomic function by heart rate variability (HRV before and after intervention period. Results: There was a significant decrease in HIT score, frequency, and intensity of headaches following treatment in both the groups. However, it was more evident in add on hydrotherapy group compared to pharmacological treatment alone group. There was also significant improvement in the HRV parameters. In particular, there was a significant decrease in heart rate (P = 0.017, increase in high frequency (HF (P = 0.014 and decrease in low frequency/HF ratio (P = 0.004 in add on hydrotherapy group. Conclusion: Our study shows that add on hydrotherapy enhanced the vagal tone in addition to reducing the frequency and intensity of headaches in migraine patients.

Increased first and second pulse harmonics in Tai Chi Chuan practitioners.

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Lu, Wan-An; Chen, Yung-Sheng; Kuo, Cheng-Deng

2016-02-29

Tai Chi Chuan (TCC) is known to be a good calisthenics for people. This study examined the relationship between pulse harmonics and autonomic nervous modulation in TCC practitioners. Power spectral measures of right pulse wave and heart rate variability (HRV) measures were compared between TCC practitioners and control subjects. Correlation analyses between pulse harmonics and HRV measures were performed using linear regression analysis. At baseline, the total power of pulse (TPp), powers of all individual pulse harmonics, normalized power of the 1(st) harmonics (nPh1) of TCC practitioners were greater, while the normalized power of the 4(th) pulse harmonics (nPh4) of TCC practitioners was smaller, than those of the controls. Similarly, the baseline standard deviation (SD(RR)), coefficient of variation (CV(RR)), and normalized high-frequency power (nHFP) of RR intervals were smaller, while the normalized very low-frequency power (nVLFP) and low-/high- frequency power ratio (LHR) were larger in the TCC practitioners. The TCC age correlated significantly and negatively with nPh1, and nearly significantly and negatively with nPh2 in the TCC practitioners. Thirty min after TCC exercise, the percentage changes in mRRI, SDRR, TP, VLFP were decreased, while the percentage changes in HR, ULFP, nLFP, and Ph2 were increased, relative to the controls. Correlation analysis shows that the %Ph2 correlates significantly and negatively with %mRRI and significantly and positively with %HR. The TCC practitioners had increased baseline total power of pulse and the 1(st) and 2(nd) pulse harmonics, and decreased power of the 4(th) pulse harmonics, along with decreased vagal modulation and increased sympathetic modulation. After TCC exercise, the power of the 2(nd) harmonics of TCC practitioners was increased which might be related to the increase in HR due to decreased vascular resistance after TCC exercise.

5-Hydroxytryptamine 1A/7 and 4alpha receptors differentially prevent opioid-induced inhibition of brain stem cardiorespiratory function.

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Wang, Xin; Dergacheva, Olga; Kamendi, Harriet; Gorini, Christopher; Mendelowitz, David

2007-08-01

Opioids evoke respiratory depression, bradycardia, and reduced respiratory sinus arrhythmia, whereas serotonin (5-HT) agonists stimulate respiration and cardiorespiratory interactions. This study tested whether serotonin agonists can prevent the inhibitory effects of opioids on cardiorespiratory function. Spontaneous and rhythmic inspiratory-related activity and gamma-aminobutyric acid (GABA) neurotransmission to premotor parasympathetic cardioinhibitory neurons in the nucleus ambiguus were recorded simultaneously in an in vitro thick slice preparation. The mu-opioid agonist fentanyl inhibited respiratory frequency. The 5-hydroxytryptamine 1A/7 receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin increased respiratory frequency by itself and also prevented the fentanyl-induced respiratory depression. The 5-hydroxytryptamine 4alpha agonist BIMU-8 did not by itself change inspiratory activity but prevented the mu-opioid-mediated respiratory depression. Both spontaneous and inspiratory-evoked GABAergic neurotransmission to cardiac vagal neurons were inhibited by fentanyl. 8-Hydroxy-2-(di-n-propylamino)tetralin inhibited spontaneous but not inspiratory-evoked GABAergic activity to parasympathetic cardiac neurons. However, 8-hydroxy-2-(di-n-propylamino)tetralin differentially altered the opioid-mediated depression of inspiratory-evoked GABAergic activity but did not change the opioid-induced reduction in spontaneous GABAergic neurotransmission. In contrast, BIMU-8 did not alter GABAergic neurotransmission to cardiac vagal neurons by itself but prevented the fentanyl depression of both spontaneous and inspiratory-elicited GABAergic neurotransmission to cardiac vagal neurons. In the presence of tetrodotoxin, the inhibition of GABAergic inhibitory postsynaptic currents with fentanyl is prevented by coapplication of BIMU-8, indicating that BIMU-8 acts at presynaptic GABAergic terminals to prevent fentanyl-induced depression. These results suggest that activation of 5

Clinical Characteristics and Genetic Variability of Human Rhinovirus in Mexico

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Hilda Montero

2012-01-01

Full Text Available Human rhinovirus (HRV is a leading cause of acute respiratory infection (ARI in young children and infants worldwide and has a high impact on morbidity and mortality in this population. Initially, HRV was classified into two species: HRV-A and HRV-B. Recently, a species called HRV-C and possibly another species, HRV-D, were identified. In Mexico, there is little information about the role of HRV as a cause of ARI, and the presence and importance of species such as HRV-C are not known. The aim of this study was to determine the clinical characteristics and genetic variability of HRV in Mexican children. Genetic characterization was carried out by phylogenetic analysis of the 5′-nontranslated region (5′-NTR of the HRV genome. The results show that the newly identified HRV-C is circulating in Mexican children more frequently than HRV-B but not as frequently as HRV-A, which was the most frequent species. Most of the cases of the three species of HRV were in children under 2 years of age, and all species were associated with very mild and moderate ARI.

[Different species of human rhinovirus infection in children with acute respiratory tract infections in Beijing].

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Song, Ming-hui; Zhao, Lin-qing; Qian, Yuan; Zhu, Ru-nan; Deng, Jie; Wang, Fang; Sun, Yu; Tian, Run

2013-12-01

To understand the clinical characteristics of different groups human rhinovirus (HRV)-A, B and C infection in children with acute respiratory tract infections (ARI) in Beijing. Respiratory tract specimens (n = 1412) collected from children with ARI during Jan. 2011 to Dec. 2012 were tested for HRV by using semi-nested PCR. Gene fragments of VP4/VP2 capsid protein amplified from HRV positive specimens were sequenced for HRV genotype confirmation. Then epidemiological characteristics of these HRV-positive cases were analyzed. Among these 1412 specimens tested, 103 (7.3%) were HRV positive, including 54 (52.4%) positive for HRV-A, 14 (13.6%) for HRV-B, 35 (34.0%) for HRV-C determined by sequence analysis. The positive rates of HRV-A, B and C (2.5%, 16/638; 0.3%, 2/638 and 1.3%, 8/638) in children with acute upper respiratory tract infections (URI) were lower than those (5.8%, 36/623; 1.8%, 11/623 and 3.9%, 24/623) in children with acute lower respiratory tract infections (LRI) (P = 0.003, 0.011, 0.003). In children with LRI, the positive rates of HRV-A, C were similar to each other (P = 0.112), and both were higher than that of HRV-B (P = 0.000, P = 0.026). The severity of ARI among children positive for different groups HRV showed no significant difference evaluated by Kruskal-Wallis H test (Hc = 0.044, P > 0.05), as well as that between children co-infected with HRV and other viruses and those infected with HRV only evaluated by Wilcoxon rank sum test (Zc = 0.872, P > 0.05). HRV is one of important pathogens for children with ARI, especially LRI in Beijing. The positive rates of HRV-A and HRV-C are similar to each other, and both are higher than that of HRV-B. No significant difference was shown among children with different HRV genotypes by evaluation of the severity of ARI, and co-infections of HRV with other viruses do not significantly increase the severity of ARI.

Vagus nerve stimulation mediates protection from kidney ischemia-reperfusion injury through α7nAChR+ splenocytes.

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Inoue, Tsuyoshi; Abe, Chikara; Sung, Sun-Sang J; Moscalu, Stefan; Jankowski, Jakub; Huang, Liping; Ye, Hong; Rosin, Diane L; Guyenet, Patrice G; Okusa, Mark D

2016-05-02

The nervous and immune systems interact in complex ways to maintain homeostasis and respond to stress or injury, and rapid nerve conduction can provide instantaneous input for modulating inflammation. The inflammatory reflex referred to as the cholinergic antiinflammatory pathway regulates innate and adaptive immunity, and modulation of this reflex by vagus nerve stimulation (VNS) is effective in various inflammatory disease models, such as rheumatoid arthritis and inflammatory bowel disease. Effectiveness of VNS in these models necessitates the integration of neural signals and α7 nicotinic acetylcholine receptors (α7nAChRs) on splenic macrophages. Here, we sought to determine whether electrical stimulation of the vagus nerve attenuates kidney ischemia-reperfusion injury (IRI), which promotes the release of proinflammatory molecules. Stimulation of vagal afferents or efferents in mice 24 hours before IRI markedly attenuated acute kidney injury (AKI) and decreased plasma TNF. Furthermore, this protection was abolished in animals in which splenectomy was performed 7 days before VNS and IRI. In mice lacking α7nAChR, prior VNS did not prevent IRI. Conversely, adoptive transfer of VNS-conditioned α7nAChR splenocytes conferred protection to recipient mice subjected to IRI. Together, these results demonstrate that VNS-mediated attenuation of AKI and systemic inflammation depends on α7nAChR-positive splenocytes.

α-MSH Influences the Excitability of Feeding-Related Neurons in the Hypothalamus and Dorsal Vagal Complex of Rats

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Hong-Zai Guan

2017-01-01

Full Text Available Alpha-melanocyte-stimulating hormone (α-MSH is processed from proopiomelanocortin (POMC and acts on the melanocortin receptors, MC3 and MC4. α-MSH plays a key role in energy homeostasis. In the present study, to shed light on the mechanisms by which α-MSH exerts its anorectic effects, extracellular neuronal activity was recorded in the hypothalamus and the dorsal vagal complex (DVC of anesthetized rats. We examined the impact of α-MSH on glucose-sensing neurons and gastric distension (GD sensitive neurons. In the lateral hypothalamus (LHA, α-MSH inhibited 75.0% of the glucose-inhibited (GI neurons. In the ventromedial nucleus (VMN, most glucose-sensitive neurons were glucose-excited (GE neurons, which were mainly activated by α-MSH. In the paraventricular nucleus (PVN, α-MSH suppressed the majority of GI neurons and excited most GE neurons. In the DVC, among the 20 GI neurons examined for a response to α-MSH, 1 was activated, 16 were depressed, and 3 failed to respond. Nineteen of 24 GE neurons were activated by α-MSH administration. Additionally, among the 42 DVC neurons examined for responses to GD, 23 were excited (GD-EXC and 19 were inhibited (GD-INH. Fifteen of 20 GD-EXC neurons were excited, whereas 11 out of 14 GD-INH neurons were suppressed by α-MSH. All these responses were abolished by pretreatment with the MC3/4R antagonist, SHU9119. In conclusion, the activity of glucose-sensitive neurons and GD-sensitive neurons in the hypothalamus and DVC can be modulated by α-MSH.

Mediation Analysis with Multiple Mediators

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VanderWeele, T.J.; Vansteelandt, S.

2014-01-01

Recent advances in the causal inference literature on mediation have extended traditional approaches to direct and indirect effects to settings that allow for interactions and non-linearities. In this paper, these approaches from causal inference are further extended to settings in which multiple mediators may be of interest. Two analytic approaches, one based on regression and one based on weighting are proposed to estimate the effect mediated through multiple mediators and the effects throu...

Purinergic signalling: from discovery to current developments.

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Burnstock, Geoffrey

2014-01-01

This lecture is about the history of the purinergic signalling concept. It begins with reference to the paper by Paton & Vane published in 1963, which identified non-cholinergic relaxation in response to vagal nerve stimulation in several species, although they suggested that it might be due to sympathetic adrenergic nerves in the vagal nerve trunk. Using the sucrose gap technique for simultaneous mechanical and electrical recordings in smooth muscle (developed while in Feldberg's department in the National Institute for Medical Research) of the guinea-pig taenia coli preparation (learned when working in Edith Bülbring's smooth muscle laboratory in Oxford Pharmacology), we showed that the hyperpolarizations recorded in the presence of antagonists to the classical autonomic neurotransmitters, acetylcholine and noradrenaline, were inhibitory junction potentials in response to non-adrenergic, non-cholinergic neurotransmission, mediated by intrinsic enteric nerves controlled by vagal and sacral parasympathetic nerves. We then showed that ATP satisfied the criteria needed to identify a neurotransmitter released by these nerves. Subsequently, it was shown that ATP is a cotransmitter in all nerves in the peripheral and central nervous systems. The receptors for purines and pyrimidines were cloned and characterized in the early 1990 s, and immunostaining showed that most non-neuronal cells as well as nerve cells expressed these receptors. The physiology and pathophysiology of purinergic signalling is discussed.

Lack of a Close Relationship Between Three Strains of Human Rhinoviruses as Determined by Their RNA Sequences 1

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Yin, Fay H.; Lonberg-Holm, K.; Chan, S. P.

1973-01-01

The possible genomic homologies between three serotypes of human rhinoviruses (HRV 1A, HRV 2, and HRV 14) were investigated. First we confirmed that these viruses were unrelated by the criterion of the absence of common antigenic determinants on the surfaces of the native virions, as detected by cross-neutralization of complementfixation. RNA-RNA hybridization was then examined with purified, highly radioactive, double-stranded, replicative-form RNA and excess single-stranded virion RNA. Single-stranded RNA showed 100% homology with the minus strand from the replicative-form RNA of the same type of virus. HRV 1A, HRV 2, and HRV 14 showed low intertypic homologies; these were not significantly greater than those found between the rhinoviruses and polivirus, which were used as a negative control. The immunological relationship and the RNA homology between HRV 1A and HRV 1B were also examined by the above techniques. It was confirmed that HRV 1A and HRV 1B share some surface determinants and it was also found that HRV 1B RNA shares 70% homology with HRV 1A RNA. PMID:4126194

Lack of close relationship between three strains of human rhinoviruses as determined by their RNA sequences.

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Yin, F H; Lonberg-Holm, K; Chan, S P

1973-07-01

The possible genomic homologies between three serotypes of human rhinoviruses (HRV 1A, HRV 2, and HRV 14) were investigated. First we confirmed that these viruses were unrelated by the criterion of the absence of common antigenic determinants on the surfaces of the native virions, as detected by cross-neutralization of complementfixation. RNA-RNA hybridization was then examined with purified, highly radioactive, double-stranded, replicative-form RNA and excess single-stranded virion RNA. Single-stranded RNA showed 100% homology with the minus strand from the replicative-form RNA of the same type of virus. HRV 1A, HRV 2, and HRV 14 showed low intertypic homologies; these were not significantly greater than those found between the rhinoviruses and polivirus, which were used as a negative control. The immunological relationship and the RNA homology between HRV 1A and HRV 1B were also examined by the above techniques. It was confirmed that HRV 1A and HRV 1B share some surface determinants and it was also found that HRV 1B RNA shares 70% homology with HRV 1A RNA.

Clinical and molecular epidemiology of human rhinovirus infections in patients with hematologic malignancy.

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Jacobs, Samantha E; Lamson, Daryl M; Soave, Rosemary; Guzman, Brigitte Huertas; Shore, Tsiporah B; Ritchie, Ellen K; Zappetti, Dana; Satlin, Michael J; Leonard, John P; van Besien, Koen; Schuetz, Audrey N; Jenkins, Stephen G; George, Kirsten St; Walsh, Thomas J

2015-10-01

Human rhinoviruses (HRVs) are common causes of upper respiratory tract infection (URTI) in hematologic malignancy (HM) patients. Predictors of lower respiratory tract infection (LRTI) including the impact of HRV species and types are poorly understood. This study aims to describe the clinical and molecular epidemiology of HRV infections among HM patients. From April 2012-March 2013, HRV-positive respiratory specimens from symptomatic HM patients were molecularly characterized by analysis of partial viral protein 1 (VP1) or VP4 gene sequence. HRV LRTI risk-factors and outcomes were analyzed using multivariable logistic regression. One hundred and ten HM patients presented with HRV URTI (n=78) and HRV LRTI (n=32). Hypoalbuminemia (OR 3.0; 95% CI, 1.0-9.2; p=0.05) was independently associated with LRTI, but other clinical and laboratory markers of host immunity did not differ between patients with URTI versus LRTI. Detection of bacterial co-pathogens was common in LRTI cases (25%). Among 92 typeable respiratory specimens, there were 58 (64%) HRV-As, 12 (13%) HRV-Bs, and 21 (23%) HRV-Cs, and one Enterovirus 68. LRTI rates among HRV-A (29%), HRV-B (17%), and HRV-C (29%) were similar. HRV-A infections occurred year-round while HRV-B and HRV-C infections clustered in the late fall and winter. HRVs are associated with LRTI in HM patients. Illness severity is not attributable to specific HRV species or types. The frequent detection of bacterial co-pathogens in HRV LRTIs further substantiates the hypothesis that HRVs predispose to bacterial superinfection of the lower airways, similar to that of other community-acquired respiratory viruses. Copyright © 2015 Elsevier B.V. All rights reserved.

The vagal nerve stimulation outcome, and laryngeal effect: Otolaryngologists roles and perspective.

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Al Omari, Ahmad I; Alzoubi, Firas Q; Alsalem, Mohammad M; Aburahma, Samah K; Mardini, Diala T; Castellanos, Paul F

Epilepsy is one of the most common neurologic disorders. Vagus nerve stimulation (VNS), first investigated in 1938 and subsequently studied as a potential therapy for epilepsy. The FDA approved the use of VNS in 1997 as an adjunctive non-pharmacologic symptomatic treatment option for refractory epilepsy for adults and adolescents over 12years. VNS can cause laryngeal and voice side effects that can be managed by otolaryngologists safely and effectively. This study is to review the outcomes of vagal nerve stimulator (VNS) implantation in terms of the surgical procedures, complications, seizure frequency, and the clinical effect on larynx and vocal folds motion. Series of thirty consecutive patients who had VNS implantation between 2007 and 2014 were recruited. Seizure-frequency outcome, surgical complications and device adverse effects of VNS were retrospectively reviewed. Additional evaluation included use of the Voice Handicap Index and Maximum Phonation Time (MPT) were conducted before and after the implantation. Videolaryngoscopy was used to evaluate the vocal fold mobility before and after the VNS implantation. Seizure frequency reduction over a minimum of 2years of follow up demonstrated: 100% in seizure frequency reduction in 1 patient, drastic reduction in seizure frequency (70-90%) in 9 patients, a good reduction in terms of seizure frequency (50%) in 8 patients, a 30% reduction in 5 patients, no response in 6 patients, and 1 patient had increased frequency. The most commonly reported adverse effects after VNS activation were coughing and voice changes with pitch breaks, as well as mild intermittent shortness of breath in 33% of patients. For those patients secondary supraglottic muscle tension and hyper function with reduced left vocal fold mobility were noticed on videolaryngoscopy, though none had aspiration problems. Surgical complications included a wound dehiscence in one patient (3%) which was surgically managed, minor intra-operative bleeding 3%; a

Mediation analysis with time varying exposures and mediators.

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VanderWeele, Tyler J; Tchetgen Tchetgen, Eric J

2017-06-01

In this paper we consider causal mediation analysis when exposures and mediators vary over time. We give non-parametric identification results, discuss parametric implementation, and also provide a weighting approach to direct and indirect effects based on combining the results of two marginal structural models. We also discuss how our results give rise to a causal interpretation of the effect estimates produced from longitudinal structural equation models. When there are time-varying confounders affected by prior exposure and mediator, natural direct and indirect effects are not identified. However, we define a randomized interventional analogue of natural direct and indirect effects that are identified in this setting. The formula that identifies these effects we refer to as the "mediational g-formula." When there is no mediation, the mediational g-formula reduces to Robins' regular g-formula for longitudinal data. When there are no time-varying confounders affected by prior exposure and mediator values, then the mediational g-formula reduces to a longitudinal version of Pearl's mediation formula. However, the mediational g-formula itself can accommodate both mediation and time-varying confounders and constitutes a general approach to mediation analysis with time-varying exposures and mediators.

Reduced heart rate variability in chronic severe traumatic brain injury: Association with impaired emotional and social functioning, and potential for treatment using biofeedback.

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Francis, Heather M; Fisher, Alana; Rushby, Jacqueline A; McDonald, Skye

2016-01-01

Heart rate variability (HRV) may provide an index of capacity for social functioning and may be remediated by HRV biofeedback. Given reductions in HRV are found following traumatic brain injury (TBI), the present study aimed to determine whether lower HRV in TBI is associated with social function, and whether HRV biofeedback might be a useful remediation technique in this population. Resting state HRV and measures of social and emotional processing were collected in 30 individuals with severe TBI (3-34 years post-injury) and 30 controls. This was followed by a single session of HRV biofeedback. HRV was positively associated with social cognition and empathy, and negatively associated with alexithymia for the TBI group. Both TBI and control groups showed significantly increased HRV on both time-domain (i.e., SDNN, rMSSD) and frequency-domain measures (LF, HF, LF:HF ratio) during biofeedback compared to baseline. These results suggest that decreased HRV is linked to social and emotional function following severe TBI, and may be a novel target for therapy using HRV biofeedback techniques.

Human rhinovirus infections in rural Thailand: epidemiological evidence for rhinovirus as both pathogen and bystander.

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Alicia M Fry

Full Text Available BACKGROUND: We describe human rhinovirus (HRV detections in SaKaeo province, Thailand. METHODS: From September 1, 2003-August 31, 2005, we tested hospitalized patients with acute lower respiratory illness and outpatient controls without fever or respiratory symptoms for HRVs with polymerase chain reaction and molecularly-typed select HRVs. We compared HRV detection among hospitalized patients and controls and estimated enrollment adjusted incidence. RESULTS: HRVs were detected in 315 (16% of 1919 hospitalized patients and 27 (9.6% of 280 controls. Children had the highest frequency of HRV detections (hospitalized: <1 year: 29%, 1-4 year: 29%, ≥ 65 years: 9%; controls: <1 year: 24%, 1-4 year: 14%, ≥ 65 years: 2.8%. Enrollment adjusted hospitalized HRV detection rates were highest among persons aged <1 year (1038/100,000 persons/year, 1-4 years (457, and ≥ 65 years (71. All three HRV species were identified, HRV-A was the most common species in most age groups including children aged <1 year (61% and all adult age groups. HRV-C was the most common species in the 1-4 year (51% and 5-19 year age groups (54%. Compared to controls, hospitalized adults (≥ 19 years and children were more likely to have HRV detections (odds ratio [OR]: 4.8, 95% confidence interval [CI]: 1.5, 15.8; OR: 2.0, CI: 1.2, 3.3, respectively and hospitalized children were more likely to have HRV-A (OR 1.7, CI: 0.8, 3.5 or HVR-C (OR 2.7, CI: 1.2, 5.9 detection. CONCLUSIONS: HRV rates were high among hospitalized children and the elderly but asymptomatic children also had substantial HRV detection. HRV (all species, and HRV-A and HRV-C detections were epidemiologically-associated with hospitalized illness. Treatment or prevention modalities effective against HRV could reduce hospitalizations due to HRV in Thailand.

Human rotavirus subgroups and severity of associated diarrhoea in Ghana.

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Armah, George E.; Hori, Hiroki; Anyanful, Akwasi; Addo, Julius A.; Commey, Joseph O.; Kamiya, Hitoshi; Nkrumah, Francis K.

1995-11-01

In a 12 month study of children with acute diarrhoea seeking medical care in 2 hospitals in Accra, Ghana, 16.3% were found to be infected with human rotaviruses (HRV). Vomiting and diarrhoea were the main symptoms observed. HRV infection was frequently associated with severe diarrhoea. Vomiting was however less frequent in HRV associated diarrhoea than in non HRV diarrhoea. No significant association was observed between the severity of dehydration and HRV infection. Subgroup II HRV was the predominant subgroup identified with the dominant serotypes being HRV serotypes 1 and 4. Poly-acrylamide gel electrophoresis of HRV RNAs isolated from 40 positive stool samples revealed the existence of 7 distinct electrophoretic migration patterns in the study population.

Cardiac vagal control and theoretical models of co-occurring depression and anxiety: A cross-sectional psychophysiological study of community elderly

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Chen Hsi-Chung

2012-07-01

Full Text Available Abstract Background In order to elucidate the complex relationship between co-occurring depression and anxiety with cardiac autonomic function in the elderly, this study examined the correlation between cardiac vagal control (CVC and pre-defined, theoretical factors from the Hospital Anxiety and Depression Scale (HADS. Methods Three hundred fifty-four randomly selected Chinese male subjects aged ≥65 years and living in the community were enrolled. CVC was measured using a frequency-domain index of heart rate variability. Results Confirmatory factor analysis showed that the flat tripartite model of HADS provided a modest advantage in model fit when compared with other theoretical factor solutions. In the flat tripartite model, there was a significant negative association between anhedonic depression and CVC. In contrast, autonomic anxiety showed a significant positive correlation with CVC. In the hierarchical tripartite model, negative affectivity was not directly associated with CVC; instead, it had positive and negative indirect effects on CVC via autonomic anxiety and anhedonic depression, respectively. As scores for negative affectivity increased, these specific indirect effects diminished. Conclusions Among competing models of co-occurring depression and anxiety, constructs from tripartite models demonstrate fair conformity with the data but unique and distinct correlations with CVC. Negative affectivity may determine the relationship of anhedonic depression and autonomic anxiety with CVC. Separating affective symptoms under the constructs of the tripartite models helps disentangle complex associations between co-occurring depression and anxiety with CVC.

Effectiveness of a smartphone-based worry-reduction training for stress reduction: A randomized-controlled trial.

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Versluis, Anke; Verkuil, Bart; Spinhoven, Philip; F Brosschot, Jos

2018-04-03

Perseverative cognition (e.g. worry) and unconscious stress are suggested to be important mediators in the relation between stressors and physiological health. We examined whether a smartphone-based worry-reduction training improved a physiological marker of stress (i.e. increased heart rate variability [HRV]) and unconscious stress. Randomised-controlled trial was conducted with individuals reporting work stress (n = 136). Participants were randomised to the experimental, control or waitlist condition (resp. EC, CC, WL). The EC and CC registered emotions five times daily for four weeks. The EC additionally received a worry-reduction training with mindfulness exercises. Primary outcome was 24-h assessments of HRV measured at pre-, mid- and post-intervention. Secondary outcomes were implicit affect and stress. Effects on heart rate and other psychological outcomes were explored. A total of 118 participants completed the study. No change from pre- to post-intervention was observed for the primary or secondary outcomes. The change over time was not different between conditions. Findings suggest that the training was ineffective for improving HRV or psychological stress. Future studies may focus on alternative smartphone-based stress interventions, as stress levels are high in society. There is need for easy interventions and smartphones offer possibilities for this.

Interventional Effects for Mediation Analysis with Multiple Mediators.

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Vansteelandt, Stijn; Daniel, Rhian M

2017-03-01

The mediation formula for the identification of natural (in)direct effects has facilitated mediation analyses that better respect the nature of the data, with greater consideration of the need for confounding control. The default assumptions on which it relies are strong, however. In particular, they are known to be violated when confounders of the mediator-outcome association are affected by the exposure. This complicates extensions of counterfactual-based mediation analysis to settings that involve repeatedly measured mediators, or multiple correlated mediators. VanderWeele, Vansteelandt, and Robins introduced so-called interventional (in)direct effects. These can be identified under much weaker conditions than natural (in)direct effects, but have the drawback of not adding up to the total effect. In this article, we adapt their proposal to achieve an exact decomposition of the total effect, and extend it to the multiple mediator setting. Interestingly, the proposed effects capture the path-specific effects of an exposure on an outcome that are mediated by distinct mediators, even when-as often-the structural dependence between the multiple mediators is unknown, for instance, when the direction of the causal effects between the mediators is unknown, or there may be unmeasured common causes of the mediators.

Iota-Carrageenan is a potent inhibitor of rhinovirus infection

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Meier Christiane

2008-09-01

Full Text Available Abstract Background Human rhinoviruses (HRVs are the predominant cause of common cold. In addition, HRVs are implicated in the worsening of COPD and asthma, as well as the loss of lung transplants. Despite significant efforts, no anti-viral agent is approved for the prevention or treatment of HRV-infection. Results In this study we demonstrate that Iota-Carrageenan, a sulphated polysaccharide derived from red seaweed, is a potent anti-rhinoviral substance in-vitro. Iota-Carrageenan reduces HRV growth and inhibits the virus induced cythopathic effect of infected HeLa cells. In addition, Iota-Carrageenan effectively prevents the replication of HRV1A, HRV2, HRV8, HRV14, HRV16, HRV83 and HRV84 in primary human nasal epithelial cells in culture. The data suggest that Iota-Carrageenan acts primarily by preventing the binding or the entry of virions into the cells. Conclusion Since HRV infections predominately occur in the nasal cavity and the upper respiratory tract, a targeted treatment with a product containing Iota-Carrageenan is conceivable. Clinical trials are needed to determine whether Iota-Carrageenan-based products are effective in the treatment or prophylaxis of HRV infections.

Estimation of causal mediation effects for a dichotomous outcome in multiple-mediator models using the mediation formula.

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Wang, Wei; Nelson, Suchitra; Albert, Jeffrey M

2013-10-30

Mediators are intermediate variables in the causal pathway between an exposure and an outcome. Mediation analysis investigates the extent to which exposure effects occur through these variables, thus revealing causal mechanisms. In this paper, we consider the estimation of the mediation effect when the outcome is binary and multiple mediators of different types exist. We give a precise definition of the total mediation effect as well as decomposed mediation effects through individual or sets of mediators using the potential outcomes framework. We formulate a model of joint distribution (probit-normal) using continuous latent variables for any binary mediators to account for correlations among multiple mediators. A mediation formula approach is proposed to estimate the total mediation effect and decomposed mediation effects based on this parametric model. Estimation of mediation effects through individual or subsets of mediators requires an assumption involving the joint distribution of multiple counterfactuals. We conduct a simulation study that demonstrates low bias of mediation effect estimators for two-mediator models with various combinations of mediator types. The results also show that the power to detect a nonzero total mediation effect increases as the correlation coefficient between two mediators increases, whereas power for individual mediation effects reaches a maximum when the mediators are uncorrelated. We illustrate our approach by applying it to a retrospective cohort study of dental caries in adolescents with low and high socioeconomic status. Sensitivity analysis is performed to assess the robustness of conclusions regarding mediation effects when the assumption of no unmeasured mediator-outcome confounders is violated. Copyright © 2013 John Wiley & Sons, Ltd.

Estimation of Causal Mediation Effects for a Dichotomous Outcome in Multiple-Mediator Models using the Mediation Formula

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Nelson, Suchitra; Albert, Jeffrey M.

2013-01-01

Mediators are intermediate variables in the causal pathway between an exposure and an outcome. Mediation analysis investigates the extent to which exposure effects occur through these variables, thus revealing causal mechanisms. In this paper, we consider the estimation of the mediation effect when the outcome is binary and multiple mediators of different types exist. We give a precise definition of the total mediation effect as well as decomposed mediation effects through individual or sets of mediators using the potential outcomes framework. We formulate a model of joint distribution (probit-normal) using continuous latent variables for any binary mediators to account for correlations among multiple mediators. A mediation formula approach is proposed to estimate the total mediation effect and decomposed mediation effects based on this parametric model. Estimation of mediation effects through individual or subsets of mediators requires an assumption involving the joint distribution of multiple counterfactuals. We conduct a simulation study that demonstrates low bias of mediation effect estimators for two-mediator models with various combinations of mediator types. The results also show that the power to detect a non-zero total mediation effect increases as the correlation coefficient between two mediators increases, while power for individual mediation effects reaches a maximum when the mediators are uncorrelated. We illustrate our approach by applying it to a retrospective cohort study of dental caries in adolescents with low and high socioeconomic status. Sensitivity analysis is performed to assess the robustness of conclusions regarding mediation effects when the assumption of no unmeasured mediator-outcome confounders is violated. PMID:23650048

Causal mediation analysis with multiple causally non-ordered mediators.

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Taguri, Masataka; Featherstone, John; Cheng, Jing

2018-01-01

In many health studies, researchers are interested in estimating the treatment effects on the outcome around and through an intermediate variable. Such causal mediation analyses aim to understand the mechanisms that explain the treatment effect. Although multiple mediators are often involved in real studies, most of the literature considered mediation analyses with one mediator at a time. In this article, we consider mediation analyses when there are causally non-ordered multiple mediators. Even if the mediators do not affect each other, the sum of two indirect effects through the two mediators considered separately may diverge from the joint natural indirect effect when there are additive interactions between the effects of the two mediators on the outcome. Therefore, we derive an equation for the joint natural indirect effect based on the individual mediation effects and their interactive effect, which helps us understand how the mediation effect works through the two mediators and relative contributions of the mediators and their interaction. We also discuss an extension for three mediators. The proposed method is illustrated using data from a randomized trial on the prevention of dental caries.

[Treatment of recurrent neurocardiogenic syncope with cardiac inhibitors with ipratropium bromide].

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Friederich, H-C; Michaelsen, J; Hesse, C; Schellberg, D; Schwab, M; Herzog, W

2004-06-01

Pharmacological approaches for the treatment of cardioinhibitory vasovagal syncope are controversially discussed in the literature. In acute treatment of neurocardiogenic syncope, anticholinergics (atropine) are used effectively. Randomised and placebo-controlled clinical trials evaluating the preventive significance of anticholinergic agents in the therapy of cardioinhibitory vasovagal syncope are still missing. We report the case of an 18-year-old male patient with recurrent convulsive, cardioinhibitory neurocardiogenic syncope. Vasovagal syncope occurred predominantly as centrally induced syncope triggered by negative emotions such as fear or by seeing blood. Under resting conditions, the patient revealed increased parasympathetic tone with nocturnal bradycardia of 38 beats/min. In the course of head-up tilt table testing a cardioinhibitory syncope with an asystolic pause of 10 seconds occurred without any prodromes after 10 minutes of upright positioning. In order to inhibit parasympathetic tone, medication with ipratropiumbromide was initiated. Time-variant analysis of heart rate variability (autoregressive model) during head-up tilt table testing showed under the medication with ipratropiumbromide a vagal mediated cardioinhibition to 56 beats/min, but no further sinus arrest. Throughout clinical follow-up of 6 months the patient remained syncope-free under the medication. The usefulness of ipratropiumbromide in inhibiting vagal mediated cardioinhibition will be discussed referring to the case report and to studies evaluating anticholinergic agents in the treatment of neurocardiogenic syncope.

Mediatization

DEFF Research Database (Denmark)

Hjarvard, Stig

2017-01-01

Mediatization research shares media effects studies' ambition of answering the difficult questions with regard to whether and how media matter and influence contemporary culture and society. The two approaches nevertheless differ fundamentally in that mediatization research seeks answers...... to these general questions by distinguishing between two concepts: mediation and mediatization. The media effects tradition generally considers the effects of the media to be a result of individuals being exposed to media content, i.e. effects are seen as an outcome of mediated communication. Mediatization...... research is concerned with long-term structural changes involving media, culture, and society, i.e. the influences of the media are understood in relation to how media are implicated in social and cultural changes and how these processes come to create new conditions for human communication and interaction...

Sympatho-vagal balance, as quantified by ANSindex, predicts post spinal hypotension and vasopressor requirement in parturients undergoing lower segmental cesarean section: a single blinded prospective observational study.

Science.gov (United States)

Prashanth, Anitha; Chakravarthy, Murali; George, Antony; Mayur, Rohini; Hosur, Rajathadri; Pargaonkar, Sumant

2017-08-01

Hypotension subsequent to spinal anesthesia occurs in a significant number of parturients undergoing lower segment caesarian section. Currently available methods to predict the incidence of hypotension, its severity and the outcome are sub-optimal. Many workers have used basal heart rate as one of the predictors. But using this method it is not possible to objectively analyze and predict the extent and severity of hypotension. We used an equipment measuring the level of sympatho-vagal balance, ANSiscope™, which derives these values from computed value of RR interval variability. We made a single measure of the value which was blinded to the patient and the anesthesiologist. We studied one hundred eight patients who underwent lower segment caesarian section under spinal anesthesia and found the variability of preoperative ANSindex (% activity displayed by the equipment) from 9 to 65 %. Higher ANSindex value was significantly associated with post spinal hypotension (p 0.017). A value of 24 % indicated the critical level above which hypotension appeared commonly. The ANSindex value might help anesthesiologist to anticipate and prepare for hypotension that is likely to ensue.

Intercultural Mediation

OpenAIRE

Dragos Marian Radulescu; Denisa Mitrut

2012-01-01

The Intercultural Mediator facilitates exchanges between people of different socio-cultural backgrounds and acts as a bridge between immigrants and national and local associations, health organizations, services and offices in order to foster integration of every single individual. As the use mediation increases, mediators are more likely to be involved in cross-cultural mediation, but only the best mediators have the opportunity to mediate cross border business disputes or international poli...

Investigation of extraesophageal gastroesophageal reflux disease

Science.gov (United States)

Tsoukali, Emmanouela; Sifrim, Daniel

2013-01-01

The most common extraesophageal manifestations of gastroesophageal reflux disease (GERD) include chronic cough, asthma and laryngitis. There are two mechanisms proposed to explain extraesophageal syndromes caused by GERD. The first one is a direct way via irritation and/or microaspiration and the second one is an indirect, vagally mediated way. The investigation of extraesophageal manifestations of GERD is difficult and the empirical therapy with proton pump inhibitors usually double dose for at least three months is still the most common approach. PMID:24714277

Nociceptor sensory neurons suppress neutrophil and γδ T cell responses in bacterial lung infections and lethal pneumonia.

Science.gov (United States)

Baral, Pankaj; Umans, Benjamin D; Li, Lu; Wallrapp, Antonia; Bist, Meghna; Kirschbaum, Talia; Wei, Yibing; Zhou, Yan; Kuchroo, Vijay K; Burkett, Patrick R; Yipp, Bryan G; Liberles, Stephen D; Chiu, Isaac M

2018-05-01

Lung-innervating nociceptor sensory neurons detect noxious or harmful stimuli and consequently protect organisms by mediating coughing, pain, and bronchoconstriction. However, the role of sensory neurons in pulmonary host defense is unclear. Here, we found that TRPV1 + nociceptors suppressed protective immunity against lethal Staphylococcus aureus pneumonia. Targeted TRPV1 + -neuron ablation increased survival, cytokine induction, and lung bacterial clearance. Nociceptors suppressed the recruitment and surveillance of neutrophils, and altered lung γδ T cell numbers, which are necessary for immunity. Vagal ganglia TRPV1 + afferents mediated immunosuppression through release of the neuropeptide calcitonin gene-related peptide (CGRP). Targeting neuroimmunological signaling may be an effective approach to treat lung infections and bacterial pneumonia.