Buschman, H.P.J.; Storm, Corstiaan J.; Duncker, Dirk J.; Verdouw, Pieter D.; van der Aa, Hans E.; van der Kemp, Peter
Objectives: There is ample and well-established evidence that direct electrical stimulation of the vagus nerve can change heart rate in animals and humans. Since tachyarrhythmias cannot always be controlled through medication, we sought, in this pilot study, to elucidate whether a clinical
Wu, Yuejin; Rasmussen, Tyler P; Koval, Olha M; Joiner, Mei-Ling A; Hall, Duane D; Chen, Biyi; Luczak, Elizabeth D; Wang, Qiongling; Rokita, Adam G; Wehrens, Xander H T; Song, Long-Sheng; Anderson, Mark E
Heart rate increases are a fundamental adaptation to physiological stress, while inappropriate heart rate increases are resistant to current therapies. However, the metabolic mechanisms driving heart rate acceleration in cardiac pacemaker cells remain incompletely understood. The mitochondrial calcium uniporter (MCU) facilitates calcium entry into the mitochondrial matrix to stimulate metabolism. We developed mice with myocardial MCU inhibition by transgenic expression of a dominant-negative (DN) MCU. Here, we show that DN-MCU mice had normal resting heart rates but were incapable of physiological fight or flight heart rate acceleration. We found that MCU function was essential for rapidly increasing mitochondrial calcium in pacemaker cells and that MCU-enhanced oxidative phoshorylation was required to accelerate reloading of an intracellular calcium compartment before each heartbeat. Our findings show that MCU is necessary for complete physiological heart rate acceleration and suggest that MCU inhibition could reduce inappropriate heart rate increases without affecting resting heart rate.
Verheyden, Bart; Couckuyt, Kurt; Liu, Jiexin; Aubert, Andre
During everyday life, gravity constantly stresses the human circulation by diminishing venous return in the upright position. This induces baroreflex-mediated cardiovascular adjustments that are aimed to prevent the blood pressure from falling. In weightlessness, gravitational pressure gradients do not arise in the circulation so that baroreflex function remains chronically unchallenged. This may contribute to the development of post spaceflight orthostatic intolerance. The purpose of this study was to evaluate respiratory modulation and baroreflex control of heart rate after a week of weightlessness in space. We tested the hypothesis that cardiovascular control in space will be similar to the baseline supine condition on Earth. We studied nine male cosmonauts during seven different space missions aboard the ISS (age 40 - 52 yrs, height 1.69 - 1.85 m, weight 67 - 90 kg). Data collection was performed between 30 and 45 days before launch in the standing and supine positions, and after 8 days in space. Cosmonauts were carefully trained to perform in-flight data collection by themselves. They were instructed to pace their breathing to a fixed rate of 12 breaths per minute (0.2 Hz) for a total duration of 3 minutes. The electrocardiogram and beat-by-beat finger arterial blood pressure were recorded at 1-kHz sample rate. Respiratory rate was evaluated using an abdominal pressure sensor. We used power spectral analysis to calculate respiratory sinus arrhythmia (RSA) as well as the low-frequency (0.04 - 0.15 Hz) powers of spontaneous oscillations in heart rate and systolic blood pressure. Baroreflex sensitivity (BRS) was estimated in the time domain using cross-correlation analysis. As expected, there was a rise in heart rate upon assuming the standing position before space- flight (59 ± 6 to 79 ± 11 beats per min; p ¡ 0.001). This was accompanied by an increase in mean arterial blood pressure (84 ± 6 to 93 ± 6 mmHg; p ¡ 0.001). Standing up further induced a marked
Jong, Wybren de
Noradrenaline injected bilaterally into the brainstem in the area of the nucleus tractus solitarii decreased systemic arterial blood pressure and heart rate of anesthetized rats. The effect of noradrenaline was prevented by a preceding injection of the α-adrenergic blocking agent phentolamine, at
Lee, Jong S; Morrow, Don; Andresen, Michael C; Chang, Kyoung S K
Isoflurane inhibits baroreflex control of heart rate (HR) by poorly understood mechanisms. The authors examined whether suprapontine central nervous system cardiovascular regulatory sites are required for anesthetic depression. The effects of isoflurane (1 and 2 rat minimum alveolar concentration [MAC]) on the baroreflex control of HR were determined in sham intact and midcollicular-transected decerebrate rats. Intravenous phenylephrine (0.2-12 microg/kg) and nitroprusside (1-60 microg/kg) were used to measure HR responses to peak changes in mean arterial pressure (MAP). Sigmoidal logistic curve fits to HR-MAP data assessed baroreflex sensitivity (HR/MAP), HR range, lower and upper HR plateau, and MAP at half the HR range (BP50). Four groups (two brain intact and two decerebrate) were studied before, during, and after isoflurane. To assess sympathetic and vagal contributions to HR baroreflex, beta-adrenoceptor (1 mg/kg atenolol) or muscarinic (0.5 mg/kg methyl atropine) antagonists were administered systemically. Decerebration did not alter resting MAP and HR or baroreflex parameters. Isoflurane depressed baroreflex slope and HR range in brain-intact and decerebrate rats. In both groups, 1 MAC reduced HR range by depressing peak reflex tachycardia. Maximal reflex bradycardia during increases in blood pressure was relatively preserved. Atenolol during 1 MAC did not alter maximum reflex tachycardia. In contrast, atropine during 1 MAC fully blocked reflex bradycardia. Therefore, 1 MAC predominantly depresses sympathetic components of HR baroreflex. Isoflurane at 2 MAC depressed both HR plateaus and decreased BP50 in both groups. Isoflurane depresses HR baroreflex control by actions that do not require suprapontine central nervous system sites. Isoflurane actions seem to inhibit HR baroreflex primarily by the sympathetic nervous system.
Rienstra, Michiel; Van Gelder, Isabelle C
In the last few years, there has been a major shift in the treatment of atrial fibrillation (AF) in the setting of hear failure (HF), from rhythm to ventricular rate control in most patients with both conditions. In this article, the authors focus on ventricular rate control and discuss the
Neijts, Melanie; Van Lien, Rene; Kupper, Nina; Boomsma, Dorret; Willemsen, Gonneke; de Geus, Eco J C
This study estimated the heritability of 24-h heart rate variability (HRV) measures, while considering ceiling effects on HRV at low heart rates during the night. HRV was indexed by the standard deviation of all valid interbeat intervals (SDNN), the root mean square of differences between valid, successive interbeat intervals (RMSSD), and peak-valley respiratory sinus arrhythmia (pvRSA). Sleep and waking levels of cardiac vagal control were assessed in 1,003 twins and 285 of their non-twin siblings. Comparable heritability estimates were found for SDNN (46%-53%), RMSSD (49%-54%), and pvRSA (48%-57%) during the day and night. A nighttime ceiling effect was revealed in 10.7% of participants by a quadratic relationship between mean pvRSA and the interbeat interval. Excluding these participants did not change the heritability estimates. The genetic factors influencing ambulatory pvRSA, RMSSD, and SDNN largely overlap. These results suggest that gene-finding studies may pool the different cardiac vagal indices and that exclusion of participants with low heart rates is not required. Copyright © 2014 Society for Psychophysiological Research.
Daly, C.A.; Clemens, F.; Sendon, J.L.; Tavazzi, L.; Boersma, E.; Danchin, N.; Delahaye, F.; Gitt, A.; Julian, D.; Mulcahy, D.; Ruzyllo, W.; Thygesen, K.; Verheugt, F.W.A.; Fox, K.M.
AIMS: To examine resting heart rate (HR) in a population presenting with stable angina in relation to prior and subsequent pharmacological treatment, comorbid conditions and clinical outcome. METHODS AND RESULTS: The European Heart Survey was a prospective, observational, cohort study of 3779
Anselmino, Matteo; Camporeale, Carlo; Saglietto, Andrea; Gaita, Fiorenzo; Ridolfi, Luca
Background. Despite the routine prescription of rate control therapy for atrial fibrillation (AF), clinical evidence demonstrating a heart rate target is lacking. Aim of the present study was to run a mathematical model simulating AF episodes with a different heart rate (HR) to predict hemodynamic parameters for each situation. Methods. The lumped model, representing the pumping heart together with systemic and pulmonary circuits, was run to simulate AF with HR of 50, 70, 90, 110 and 130 bpm, respectively. Results. Left ventricular pressure increased by 56.7%, from 33.92+-37.56 mmHg to 53.15+-47.56 mmHg, and mean systemic arterial pressure increased by 27.4%, from 82.66+-14.04 mmHg to 105.29+-7.63 mmHg, at the 50 and 130 bpm simulations, respectively. Stroke volume (from 77.45+-8.5 to 39.09+-8.08 mL), ejection fraction (from 61.1+-4.4 to 39.32+-5.42%) and stroke work (SW, from 0.88+-0.04 to 0.58+-0.09 J) decreased by 49.5, 35.6 and 34.2%, at the 50 and 130 bpm simulations, respectively. In addition, oxygen co...
Sugihara, George; Allan, Walter; Sobel, Daniel; Allan, Kenneth D.
Nonlinear analyses of infant heart rhythms reveal a marked rise in the complexity of the electrocardiogram with maturation. We find that normal mature infants (gestation >= 35 weeks) have complex and distinctly nonlinear heart rhythms (consistent with recent reports for healthy adults) but that such nonlinearity is lacking in preterm infants (gestation physiological states.
Ganesha, Suhas; Thirthalli, Jagadisha; Muralidharan, Kesavan; Benegal, Vivek; Gangadhar, Bangalore N
Alcohol dependence can lead to autonomic neuropathy resulting in increased cardiac morbidity and mortality. This has previously been evaluated using heart-rate variability. We compared sleep heart-rate variability of alcohol-dependent patients with that of healthy controls in this study. This study was conducted at NIMHANS, Bangalore. A case control study design was adopted. Sleep heart-rate variability of 20 male alcohol-dependent inpatients was recorded on the 5(th) day after detoxification. Sleep heart-rate variability was also recorded in 18 age- and gender-matched healthy controls. The groups were compared using t-test for continuous variables and Chi-squared test for discrete variables. Both time and frequency domain measures were significantly lower in the patients as compared to the controls, indicating decreased HRV in alcohol-dependent individuals. Decreased HRV in alcohol dependence indicates potential autonomic neuropathy.
Tharion, Elizabeth; Samuel, Prasanna; Rajalakshmi, R; Gnanasenthil, G; Subramanian, Rajam Krishna
Studies show that yogic type of breathing exercises reduces the spontaneous respiratory rate. However, there are no conclusive studies on the effects of breathing exercise on heart rate variability. We investigated the effects of non-yogic breathing exercise on respiratory rate and heart rate variability. Healthy subjects (21-33 years, both genders) were randomized into the intervention group (n=18), which performed daily deep breathing exercise at 6 breaths/min (0.1 Hz) for one month, and a control group (n=18) which did not perform any breathing exercise. Baseline respiratory rate and short-term heart rate variability indices were assessed in both groups. Reassessment was done after one month and the change in the parameters from baseline was computed for each group. Comparison of the absolute changes [median (inter-quartile ranges)] of the parameters between the intervention and control group showed a significant difference in the spontaneous respiratory rate [intervention group -2.50 (-4.00, -1.00), control group 0.00 (-1.00, 1.00), cycles/min, Prate and cardiac autonomic modulation of the intervention group were significant, when compared to the changes in the control group. Thus practice of deep slow breathing exercise improves heart rate variability in healthy subjects, without altering their cardiac autonomic balance. These findings have implications in the use of deep breathing exercises to improve cardiac autonomic control in subjects known to have reduced heart rate variability.
Full Text Available Heart failure (HF with atrial fibrillation (AF is correlated with worse prognosis requiring special approach.Rate control has been the first line of treatment in cases of HF and HF. On the other hand, rhythm controlhas been proven to be effective in returning sinus rhythm resulting in better prognosis for patients with HFbut not HF. Its role in cocurring cases of HF and AF is not fully understood. Thus, this study aims to analysewhether pharmacologic rhythm control can be applied to cases of HF and AF to reduce mortality. A searchwas conducted via PubMed, Medline, ProQuest, and Cochrane Database on January 2016. One study wasselected after filtering process by inclusion and exclusion criteria and critical appraisal was performed. It wasfound that there was rhythm control and rate control do no have favouring effect towards mortality shown byRR 1.03 (95% CI 0.90-1.17, p=0.69. Rate control has protective effect towards hospitalizations by RR of 0.92(95% CI 0.86 – 0.98, p=0.008, NNT=19. To conclude, rhythm control is not superior to rate control in reducingmortality and rate control should be still be considered as first line treatment of HF and AF. Keywords: heart failure, pharmacologic rhythm control, rate control, atrial fibrillation Farmakologis Rhythm Control Dibandingkan dengan Rate Control padaKasus Gagal Jantung dan Atrial Fibrilasi Abstrak Gagal jantung dengan atrial fibrilasi berhubungan dengan prognosis yang lebih buruk dan membutuhkanpenanganan khusus. Saat ini strategi rate control merupakan terapi lini pertama pada kasus gagal jantungdan atrial fibrilasi. Rhythm control memberikan prognosis yang lebih baik pada pasien gagal jantung denganmengembalikan sinus ritme. Kegunaan rhythm control pada kasus gagal jantung dan atrial fibrilasi sampaisaat ini belum sepenuhnya dimengerti. Tujuan studi ini adalah menelaah apakah terapi farmakologis rhythmcontrol dapat menurunkan mortalitas gagal jantung dan atrial fibrilasi. Pencarian data
Haedersdal, C; Pedersen, F H; Svendsen, J H
after the myocardial infarction. A significant correlation (Spearman's correlation coefficient rs, p less than 0.05) was found between LVEF at rest and the following variables assessed at exercise test: 1) the heart rate at rest, 2) rise in heart rate, 3) ratio between maximal heart rate and heart rate...... at rest, 4) rise in systolic blood pressure, 5) rate pressure product at rest, 6) rise in rate pressure product, 7) ratio (rHR) between maximal rate pressure product and rate pressure product at rest, 8) total exercise time. The heart rate was corrected for effects caused by age (heart index (HR...
Woerman, Amanda L; Mendelowitz, David
Sulfur dioxide (SO₂) is an air pollutant that impedes neonatal development and induces adverse cardiorespiratory health effects, including tachycardia. Here, an animal model was developed that enabled characterization of (i) in vivo alterations in heart rate and (ii) altered activity in brainstem neurons that control heart rate after perinatal SO₂ exposure. Pregnant Sprague-Dawley dams and their pups were exposed to 5 parts per million SO₂ for 1 h daily throughout gestation and 6 days postnatal. Electrocardiograms were recorded from pups at 5 days postnatal to examine changes in basal and diving reflex-evoked changes in heart rate following perinatal SO₂ exposure. In vitro studies employed whole-cell patch-clamp electrophysiology to examine changes in neurotransmission to cardiac vagal neurons within the nucleus ambiguus upon SO₂ exposure using a preparation that maintains fictive inspiratory activity recorded from the hypoglossal rootlet. Perinatal SO₂ exposure increased heart rate and blunted the parasympathetic-mediated diving reflex-evoked changes in heart rate. Neither spontaneous nor inspiratory-related inhibitory GABAergic or glycinergic neurotransmission to cardiac vagal neurons was altered by SO₂ exposure. However, excitatory glutamatergic neurotransmission was decreased by 51.2% upon SO₂ exposure. This diminished excitatory neurotransmission was tetrodotoxin-sensitive, indicating SO₂ exposure impaired the activity of preceding glutamatergic neurons that synapse upon cardiac vagal neurons. Diminished glutamatergic, but unaltered inhibitory neurotransmission to cardiac vagal neurons provides a mechanism for the observed SO₂-induced elevated heart rate via an impairment of brainstem cardioinhibitory parasympathetic activity to the heart.
Kember, G; Armour, J A; Zamir, M
A model is proposed in which the relationship between individual neurons within a neural network is dynamically changing to the effect of providing a measure of "plasticity" in the control of heart rate. The neural network on which the model is based consists of three populations of neurons residing in the central nervous system, the intrathoracic extracardiac nervous system, and the intrinsic cardiac nervous system. This hierarchy of neural centers is used to challenge the classical view that the control of heart rate, a key clinical index, resides entirely in central neuronal command (spinal cord, medulla oblongata, and higher centers). Our results indicate that dynamic networking allows for the possibility of an interplay among the three populations of neurons to the effect of altering the order of control of heart rate among them. This interplay among the three levels of control allows for different neural pathways for the control of heart rate to emerge under different blood flow demands or disease conditions and, as such, it has significant clinical implications because current understanding and treatment of heart rate anomalies are based largely on a single level of control and on neurons acting in unison as a single entity rather than individually within a (plastically) interconnected network. Copyright © 2012 Elsevier Ltd. All rights reserved.
Chu, I-Hua; Lin, Yuh-Jen; Wu, Wen-Lan; Chang, Yu-Kai; Lin, I-Mei
To examine the effects of an 8-week yoga program on heart rate variability and mood in generally healthy women. Randomized controlled trial. Fifty-two healthy women were randomly assigned to a yoga group or a control group. Participants in the yoga group completed an 8-week yoga program, which comprised a 60-minute session twice a week. Each session consisted of breathing exercises, yoga pose practice, and supine meditation/relaxation. The control group was instructed not to engage in any yoga practice and to maintain their usual level of physical activity during the study. Participants' heart rate variability, perceived stress, depressive symptoms, and state and trait anxiety were assessed at baseline (week 0) and after the intervention (week 9). No measures of heart rate variability changed significantly in either the yoga or control group after intervention. State anxiety was reduced significantly in the yoga group but not in the control group. No significant changes were noted in perceived stress, depression, or trait anxiety in either group. An 8-week yoga program was not sufficient to improve heart rate variability. However, such a program appears to be effective in reducing state anxiety in generally healthy women. Future research should involve longer periods of yoga training, include heart rate variability measures both at rest and during yoga practice, and enroll women with higher levels of stress and trait anxiety.
Zuberi, Zia; Birnbaumer, Lutz; Tinker, Andrew
Multiple isoforms of inhibitory Gα-subunits (Gαi1,2,3, as well as Gαo) are present within the heart, and their role in modulating pacemaker function remains unresolved. Do inhibitory Gα-subunits selectively modulate parasympathetic heart rate responses? Published findings using a variety of experimental approaches have implicated roles for Gαi2, Gαi3, and Gαo in parasympathetic signal transduction. We have compared in vivo different groups of mice with global genetic deletion of Giα1/Gαi3, Gαi2, and Gαo against littermate controls using implanted ECG telemetry. Significant resting tachycardia was observed in Gαi2−/− and Gαo−/− mice compared with control and Gαi1−/−/Gαi3−/− mice (P heart rate variation was seen exclusively in Gαo−/− mice. Using heart rate variability (HRV) analysis, compared with littermate controls (4.02 ms2 ± 1.17; n = 6, Gαi2−/−) mice have a selective attenuation of high-frequency (HF) power (0.73 ms2 ± 0.31; n = 5, P heart rate was attenuated in Gαi2−/− mice (0.08 ± 0.04; n = 6) compared to control (0.27 ± 0.04; n = 7 P heart rate modulation in mice with Gαi2 deletion. Mice with Gαo deletion also have a defect in short-term heart rate dynamics, but this is qualitatively different to the effects of atropine, tertiapinQ, and Gαi2 deletion. In contrast, Gαi1 and Gαi3 do not appear to be essential for parasympathetic responses in vivo. PMID:18832081
Giles, Paul D; Hensel, Kendi L; Pacchia, Christina F; Smith, Michael L
Osteopathic manipulative treatment (OMT) focused on the upper cervical spine is theorized to affect the function of the vagus nerve and thereby influence the parasympathetic branch of the autonomic nervous system. This study was designed to determine the acute effect of upper cervical spine manipulation on cardiac autonomic control as measured by heart rate variability. Nineteen healthy, young adult subjects underwent three different experimental interventions administered in random order: cervical OMT, sham manipulation, and time control. Six minutes of electrocardiographic data were collected before and after each intervention, and heart rate variability was assessed by both time-domain and frequency-domain measures. No differences in resting heart rate or any measure of heart rate variability were observed between the baseline periods prior to each intervention. The OMT protocol resulted in an increase in the standard deviation of the normal-to-normal intervals (0.12±0.082 seconds, p0.11 for all variables). These data support the hypothesis that upper cervical spine manipulation can acutely affect measures of heart rate variability in healthy individuals.
Salem, Joe-Elie; El-Aissaoui, Maria; Alazard, Margaux; Hulot, Jean-Sébastien; Aissaoui, Nadia; Le-Heuzey, Jean-Yves; Funck-Brentano, Christian; Faisy, Christophe; Urien, Saik
Amiodarone is the gold-standard medication to control heart rate in critically ill patients with atrial tachyarrhythmias (ATs); however, effective doses and covariates influencing its efficacy remain unknown. We therefore performed pharmacodynamic modeling of heart rate reduction induced by amiodarone in these patients. This observational study included 80 consecutive severely ill patients receiving amiodarone to treat ATs. A total of 1348 time-heart rate observations with 361 amiodarone dose administrations were analyzed during a period of up to 6 days after hospital treatment initiation using a nonlinear mixed-effect model. Pretreatment with amiodarone before intensive care administration, paroxysmal versus persistent AT, catecholamine infusion, and fluid and magnesium loading were among the covariates assessed in the model. In case of paroxysmal AT in a patient not pretreated with amiodarone, a 300 mg intravenous loading dose combined with an 800 mg oral dose on the first day, followed by 800 mg/day orally for 4 days was effective in achieving a heart rate between 80 and 115 bpm within the first day, and to maintain it during the next 4 days. Corresponding doses were twice as high in patients with persistent AT. Use of intravenous magnesium (p amiodarone required to control heart rate is influenced by the type of AT and by other easily measurable conditions which may allow better individualization of amiodarone dosing.
Giles, Paul D.; Hensel, Kendi L.; Pacchia, Christina F.
Abstract Objectives Osteopathic manipulative treatment (OMT) focused on the upper cervical spine is theorized to affect the function of the vagus nerve and thereby influence the parasympathetic branch of the autonomic nervous system. This study was designed to determine the acute effect of upper cervical spine manipulation on cardiac autonomic control as measured by heart rate variability. Design Nineteen healthy, young adult subjects underwent three different experimental interventions administered in random order: cervical OMT, sham manipulation, and time control. Six minutes of electrocardiographic data were collected before and after each intervention, and heart rate variability was assessed by both time-domain and frequency-domain measures. Results No differences in resting heart rate or any measure of heart rate variability were observed between the baseline periods prior to each intervention. The OMT protocol resulted in an increase in the standard deviation of the normal-to-normal intervals (0.12±0.082 seconds, p0.11 for all variables). Conclusions These data support the hypothesis that upper cervical spine manipulation can acutely affect measures of heart rate variability in healthy individuals. PMID:22994907
Hayashi, Miwa; Dulchinos, Victoria Lee
Heart Rate Variability (HRV) has been reported to reflect the person's cognitive and emotional stress levels, and may offer an objective measure of human-operator's workload levels, which are recorded continuously and unobtrusively to the task performance. The present paper compares the HRV data collected during a human-in-the-loop simulation of airport ramp-traffic control operations with the controller participants' own verbal self-reporting ratings of their workload.
Wyss, C. R.; Brengelmann, G. L.; Johnson, J. M.; Rowell, L. B.; Niederberger, M.
A study was conducted to generate quantitative expressions for the influence of core temperature, skin temperature, and the rate of change of skin temperature on sweat rate, skin blood flow, and heart rate. A second goal of the study was to determine whether the use of esophageal temperature rather than the right atrial temperature as a measure of core temperature would lead to different conclusions about the control of measured effector variables.
Full Text Available David Feldman1, Terry S Elton2, Doron M Menachemi3, Randy K Wexler41Heart Failure/Transplant and VAD Programs, Minneapolis Heart Institute, Minneapolis, Minnesota, USA; 2Division of Pharmacology, College of Pharmacology, The Ohio State University, Columbus, Ohio, USA; 3Heart Failure Services, Edith Wolfson Medical Center, The Heart Institute, Sakler School of Medicine, Tel-Aviv University, Holon, Israel; 4Department of Clinical Family Medicine, The Ohio State University, Columbus, Ohio, USAAbstract: The sympathetic nervous system is involved in regulating various cardiovascular parameters including heart rate (HR and HR variability. Aberrant sympathetic nervous system expression may result in elevated HR or decreased HR variability, and both are independent risk factors for development of cardiovascular disease, including heart failure, myocardial infarction, and hypertension. Epidemiologic studies have established that impaired HR control is linked to increased cardiovascular morbidity and mortality. One successful way of decreasing HR and cardiovascular mortality has been by utilizing β-blockers, because their ability to alter cell signaling at the receptor level has been shown to mitigate the pathogenic effects of sympathetic nervous system hyperactivation. Numerous clinical studies have demonstrated that β-blocker-mediated HR control improvements are associated with decreased mortality in postinfarct and heart failure patients. Although improved HR control benefits have yet to be established in hypertension, both traditional and vasodilating β-blockers exert positive HR control effects in this patient population. However, differences exist between traditional and vasodilating β-blockers; the latter reduce peripheral vascular resistance and exert neutral or positive effects on important metabolic parameters. Clinical evidence suggests that attainment of HR control is an important treatment objective for patients with cardiovascular
Fisher, James P; Seifert, Thomas; Hartwich, Doreen
Isolated activation of metabolically sensitive skeletal muscle afferents (muscle metaboreflex) using post-exercise ischaemia (PEI) following handgrip partially maintains exercise-induced increases in arterial blood pressure (BP) and muscle sympathetic nerve activity (SNA), while heart rate (HR...... of cardiac parasympathetic reactivation on heart rate....... moderate (PEI-M) and high (PEI-H) intensity isometric handgrip performed at 25% and 40% maximum voluntary contraction, under control (no drug), parasympathetic blockade (glycopyrrolate) and beta-adrenergic blockade (metoprolol or propranalol) conditions, while beat-to-beat HR and BP were continuously...
van der Zwan, J.E.; de Vente, W.; Huizink, A.C.; Bögels, S.M.; de Bruin, E.I.
In contemporary western societies stress is highly prevalent, therefore the need for stress-reducing methods is great. This randomized controlled trial compared the efficacy of self-help physical activity (PA), mindfulness meditation (MM), and heart rate variability biofeedback (HRV-BF) in reducing
Gijsbers, L.; Moelenberg, F. J. M.; Bakker, S. J. L.; Geleijnse, J. M.
Background and aims: Increasing the intake of potassium has been shown to lower blood pressure, but whether it also affects heart rate (HR) is largely unknown. We therefore assessed the effect of potassium supplementation on HR in a meta-analysis of randomized controlled trials. Methods and results:
Ng, Ming Yen [University of Toronto, Department of Medical Imaging, Toronto General Hospital, Toronto, ON (Canada); The University of Hong Kong, Queen Mary Hospital, Department of Diagnostic Radiology, Hong Kong (China); Karimzad, Yasser; Menezes, Ravi J.; Wintersperger, Bernd J.; Li, Qin; Forero, Julian; Paul, Narinder S.; Nguyen, Elsie T. [University of Toronto, Department of Medical Imaging, Toronto General Hospital, Toronto, ON (Canada)
To evaluate the heart rate lowering effect of relaxation music in patients undergoing coronary CT angiography (CCTA), pulmonary vein CT (PVCT) and coronary calcium score CT (CCS). Patients were randomised to a control group (i.e. standard of care protocol) or to a relaxation music group (ie. standard of care protocol with music). The groups were compared for heart rate, radiation dose, image quality and dose of IV metoprolol. Both groups completed State-Trait Anxiety Inventory anxiety questionnaires to assess patient experience. One hundred and ninety-seven patients were recruited (61.9 % males); mean age 56y (19-86 y); 127 CCTA, 17 PVCT, 53 CCS. No significant difference in heart rate, radiation dose, image quality, metoprolol dose and anxiety scores. 86 % of patients enjoyed the music. 90 % of patients in the music group expressed a strong preference to have music for future examinations. The patient cohort demonstrated low anxiety levels prior to CT. Relaxation music in CCTA, PVCT and CCS does not reduce heart rate or IV metoprolol use. Patients showed low levels of anxiety indicating that anxiolytics may not have a significant role in lowering heart rate. Music can be used in cardiac CT to improve patient experience. (orig.)
Ng, Ming Yen; Karimzad, Yasser; Menezes, Ravi J; Wintersperger, Bernd J; Li, Qin; Forero, Julian; Paul, Narinder S; Nguyen, Elsie T
To evaluate the heart rate lowering effect of relaxation music in patients undergoing coronary CT angiography (CCTA), pulmonary vein CT (PVCT) and coronary calcium score CT (CCS). Patients were randomised to a control group (i.e. standard of care protocol) or to a relaxation music group (ie. standard of care protocol with music). The groups were compared for heart rate, radiation dose, image quality and dose of IV metoprolol. Both groups completed State-Trait Anxiety Inventory anxiety questionnaires to assess patient experience. One hundred and ninety-seven patients were recruited (61.9 % males); mean age 56y (19-86 y); 127 CCTA, 17 PVCT, 53 CCS. No significant difference in heart rate, radiation dose, image quality, metoprolol dose and anxiety scores. 86 % of patients enjoyed the music. 90 % of patients in the music group expressed a strong preference to have music for future examinations. The patient cohort demonstrated low anxiety levels prior to CT. Relaxation music in CCTA, PVCT and CCS does not reduce heart rate or IV metoprolol use. Patients showed low levels of anxiety indicating that anxiolytics may not have a significant role in lowering heart rate. Music can be used in cardiac CT to improve patient experience. • Relaxation music does not reduce heart rate in cardiac CT • Relaxation music does not reduce beta-blocker use in cardiac CT • Relaxation music has no effect on cardiac CT image quality • Low levels of anxiety are present in patients prior to cardiac CT • Patients enjoyed the relaxation music and this results in improved patient experience.
Bornas, Xavier; Llabrés, Jordi; Morillas-Romero, Alfonso; Aguayo-Siquier, Blanca; Balle, Maria; Tortella-Feliu, Miquel
Effective regulation of emotions requires the ability to voluntarily manage attention, i.e. attentional control (AC), which has been related to heart rate variability and vagal tone in laboratory based research. In this study, we calculated the correlation dimension (CD), the fractal-like properties (scaling exponents ?1 and ?2, and fractal dimension) and the sample entropy of heart rate time series obtained from ECG recordings (4 hours long each) taken from a sample of healthy students (n=47) during everyday activities. AC was assessed through a self-reported questionnaire. As expected, a linear positive correlation was found between AC scores and CD and entropy, but no associations were found between AC and ?1 and fractal dimension. The association between AC and ?2 was negative and marginally significant. No associations were found between AC and linear heart rate variability measures. These results show that nonlinear measures of long, everyday life, heart rate time series may provide useful information about the AC ability of healthy students.
下村, 雅昭; Shimomura, Masaaki; 羽田, 龍彦; Hata, Tatsuhiko; 上村, 桂子; Uemura, Keiko; 廣瀬, 美嘉; Hirose, Mika; 浜崎, 博; Hamazaki, Hiroshi
PURPOSE: To evaluate the effect of golf swing on the heart rate level in patients with chronic ischemic heart disease (IHD) and healthy adults. METHODS: Study subjects were 7 male patients with IHD (mean age 59.3±8.7 years) and 7 age-matched, healthy male golfers. AIl subjects underwent golf swing at driving range, during which heart rate and electrocardiogram were monitored via telemetry system. Blood pressure was taken immediately after each golf swing. RESULTS: The average heart rate value...
van der Zwan, Judith Esi; de Vente, Wieke; Huizink, Anja C.; B?gels, Susan M.; de Bruin, Esther I.
In contemporary western societies stress is highly prevalent, therefore the need for stress-reducing methods is great. This randomized controlled trial compared the efficacy of self-help physical activity (PA), mindfulness meditation (MM), and heart rate variability biofeedback (HRV-BF) in reducing stress and its related symptoms. We randomly allocated 126 participants to PA, MM, or HRV-BF upon enrollment, of whom 76 agreed to participate. The interventions consisted of psycho-education and a...
Full Text Available The present article contains a brief review on the role of vasopressinergic projections to the nucleus tractus solitarii in the genesis of reflex bradycardia and in the modulation of heart rate control during exercise. The effects of vasopressin on exercise tachycardia are discussed on the basis of both the endogenous peptide content changes and the heart rate response changes observed during running in sedentary and trained rats. Dynamic exercise caused a specific vasopressin content increase in dorsal and ventral brainstem areas. In accordance, rats pretreated with the peptide or the V1 blocker into the nucleus tractus solitarii showed a significant potentiation or a marked blunting of the exercise tachycardia, respectively, without any change in the pressure response to exercise. It is proposed that the long-descending vasopressinergic pathway to the nucleus tractus solitarii serves as one link between the two main neural controllers of circulation, i.e., the central command and feedback control mechanisms driven by the peripheral receptors. Therefore, vasopressinergic input could contribute to the adjustment of heart rate response (and cardiac output to the circulatory demand during exercise.
Mander, Gordon Thomas Waterland
Computed tomography coronary angiography patient preparation with heart rate control premedication is employed in departments across Australia. However, the methods of administration vary widely between institutions and do not always follow best practice. This aim of the study was to identify and promote best practice in the administration of heart rate premedication in computed tomography coronary angiography at a regional hospital in Australia. The Joanna Briggs Institute have validated audit and feedback tools to assist with best practice implementation projects. This project used these tools, which involve three phases of activity - a pre-implementation audit, reflecting on results and implementing strategies to address non-compliance, and a post-implementation audit to assess the outcomes. A baseline audit identified non-compliance in the majority of measured audit criteria. Following implementation of an institution-specific guideline and associated worksheet, improved compliance was shown across all audit criteria. Following the development and implementation of institution-specific evidence-based resources relating to heart rate control in computed tomography coronary angiography, a high level of compliance consistent with best practice was achieved.
Feldman, David; Elton, Terry S; Menachemi, Doron M; Wexler, Randy K
The sympathetic nervous system is involved in regulating various cardiovascular parameters including heart rate (HR) and HR variability. Aberrant sympathetic nervous system expression may result in elevated HR or decreased HR variability, and both are independent risk factors for development of cardiovascular disease, including heart failure, myocardial infarction, and hypertension. Epidemiologic studies have established that impaired HR control is linked to increased cardiovascular morbidity and mortality. One successful way of decreasing HR and cardiovascular mortality has been by utilizing β-blockers, because their ability to alter cell signaling at the receptor level has been shown to mitigate the pathogenic effects of sympathetic nervous system hyperactivation. Numerous clinical studies have demonstrated that β-blocker-mediated HR control improvements are associated with decreased mortality in postinfarct and heart failure patients. Although improved HR control benefits have yet to be established in hypertension, both traditional and vasodilating β-blockers exert positive HR control effects in this patient population. However, differences exist between traditional and vasodilating β-blockers; the latter reduce peripheral vascular resistance and exert neutral or positive effects on important metabolic parameters. Clinical evidence suggests that attainment of HR control is an important treatment objective for patients with cardiovascular conditions, and vasodilating β-blocker efficacy may aid in accomplishing improved outcomes. PMID:20539841
Ramchandra, Rohit; Hood, Sally G; May, Clive N
Heart failure (HF) is associated with increased cardiac and renal sympathetic drive, which are both independent predictors of poor prognosis. A candidate mechanism for the centrally mediated sympathoexcitation in HF is reduced synthesis of the inhibitory neuromodulator nitric oxide (NO), resulting from downregulation of neuronal NO synthase (nNOS). Therefore, we investigated the effects of increasing the levels of NO in the brain, or selectively in the paraventricular nucleus of the hypothalamus (PVN), on cardiac sympathetic nerve activity (CSNA) and baroreflex control of CSNA and heart rate in ovine pacing-induced HF. The resting level of CSNA was significantly higher in the HF than in the normal group, but the resting level of RSNA was unchanged. Intracerebroventricular infusion of the NO donor sodium nitroprusside (SNP; 500 μg · ml(-1)· h(-1)) in conscious normal sheep and sheep in HF inhibited CSNA and restored baroreflex control of heart rate, but there was no change in RSNA. Microinjection of SNP into the PVN did not cause a similar cardiac sympathoinhibition in either group, although the number of nNOS-positive cells was decreased in the PVN of sheep in HF. Reduction of endogenous NO with intracerebroventricular infusion of N(ω)-nitro-l-arginine methyl ester decreased CSNA in normal but not in HF sheep and caused no change in RSNA in either group. These findings indicate that endogenous NO in the brain provides tonic excitatory drive to increase resting CSNA in the normal state, but not in HF. In contrast, exogenously administered NO inhibited CSNA in both the normal and HF groups via an action on sites other than the PVN. Copyright © 2014 the American Physiological Society.
Kwon, Osung; Park, Saejong; Kim, Young-Joo; Min, Sun-Yang; Kim, Yoo Ri; Nam, Gi-Byoung; Choi, Kee-Joon; Kim, You-Ho
Endurance exercise protects the heart via effects on autonomic control of heart rate (HR); however, its effects on HR indices in healthy middle-aged men are unclear. This study compared HR profiles, including resting HR, increase in HR during exercise and HR recovery after exercise, in middle-aged athletes and controls. Fifty endurance-trained athletes and 50 controls (all male; mean age, 48·7 ± 5·8 years) performed an incremental symptom-limited exercise treadmill test. The electrocardiographic findings and HR profiles were evaluated. Maximal O2 uptake (52·6 ± 7·0 versus 34·8 ± 4·5 ml kg(-1) min(-1) ; PHealthy middle-aged men participating in regular endurance exercise showed more favourable exercise HR profiles and a lower incidence of PVCs during exercise than sedentary men. These results reflect the beneficial effect of endurance training on autonomic control of the heart. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.
Heart rate turbulence (HRT) is a baroreflex-mediated biphasic reaction of heart rate in response to premature ventricular beats. Heart rate turbulence is quantified by: turbulence onset (TO) reflecting the initial acceleration of heart rate following premature beat and turbulence slope (TS) describing subsequent deceleration of heart rate. Abnormal HRT identifies patients with autonomic dysfunction or impaired baroreflex sensitivity due to variety of disorders, but also may reflect changes in autonomic nervous system induced by different therapeutic modalities such as drugs, revascularization, or cardiac resynchronization therapy. More importantly, impaired HRT has been shown to identify patients at high risk of all-cause mortality and sudden death, particularly in postinfarction and congestive heart failure patients. It should be emphasized that abnormal HRT has a well-established role in stratification of postinfarction and heart failure patients with relatively preserved left ventricular ejection fraction. The ongoing clinical trials will document whether HRT can be used to guide implantation of cardioverter-defibrillators in this subset of patients, not covered yet by ICD guidelines. This review focuses on the current state-of-the-art knowledge regarding clinical significance of HRT in detection of autonomic dysfunction and regarding the prognostic significance of this parameter in predicting all-cause mortality and sudden death. © 2013.
Full Text Available Reduced dietary sodium intake (sodium reduction increases heart rate in some studies of animals and humans. As heart rate is independently associated with the development of heart failure and increased risk of premature death a potential increase in heart rate could be a harmful side-effect of sodium reduction. The purpose of the present meta-analysis was to investigate the effect of sodium reduction on heart rate. Relevant studies were retrieved from an updated pool of 176 randomized controlled trials (RCTs published in the period 1973–2014. 63 of the RCTs including 72 study populations reported data on heart rate. In a meta-analysis of these data sodium reduction increased heart rate with 1.65 beats per minute [95% CI: 1.19, 2.11], p < 0.00001, corresponding to 2.4% of the baseline heart rate. This effect was independent of baseline blood pressure. In conclusion sodium reduction increases heart rate by as much (2.4% as it decreases blood pressure (2.5%. This side-effect, which may cause harmful health effects, contributes to the need for a revision of the present dietary guidelines.
Ahmed, A K; Fakhouri, S Y; Harness, J B; Mearns, A J
The process of the breathing (input) to the heart rate (output) of man is considered for system identification by the input-output relationship, using a mathematical model expressed as integral equations. The integral equation is considered and fixed so that the identification method reduces to the determination of the values within the integral, called kernels, resulting in an integral equation whose input-output behaviour is nearly identical to that of the system. This paper uses an algorithm of kernel identification of the Volterra series which greatly reduces the computational burden and eliminates the restriction of using white Gaussian input as a test signal. A second-order model is the most appropriate for a good estimate of the system dynamics. The model contains the linear part (first-order kernel) and quadratic part (second-order kernel) in parallel, and so allows for the possibility of separation between the linear and non-linear elements of the process. The response of the linear term exhibits the oscillatory input and underdamped nature of the system. The application of breathing as input to the system produces an oscillatory term which may be attributed to the nature of sinus node of the heart being sensitive to the modulating signal the breathing wave. The negative-on diagonal seems to cause the dynamic asymmetry of the total response of the system which opposes the oscillatory nature of the first kernel related to the restraining force present in the respiratory heart rate system. The presence of the positive-off diagonal of the second-order kernel of respiratory control of heart rate is an indication of an escape-like phenomenon in the system.
WJ Jaspers; PA de Jong; PJ Kurver; MD E.J.M. Wouters
Heart-rate changes after transition from a supine to a standing posture were measured in 12 hypertensive and 12 normotensive primigravid women, in their last trimester of gestation. The subjects beat-to-beat heart-rate (HR) changes were recorded on both an ordinary cardiotocograph and on magnetic
Geisler, Fay C M; Kleinfeldt, Anne; Kubiak, Thomas
When confronted with food, restrained eaters have to inhibit the pursuit of the short-term goal of enjoying their food for the sake of the long-term goal of controlling their weight. Thus, restrained eating creates a self-control situation. In the present study we investigated the initiation of effortful self-control by food cues in accordance with the level of restrained eating. We expected that a preceding act of self-control would moderate the association between restrained eating and effortful self-control initiated by food cues. Participants (N=111) were randomly assigned to a task requiring self-control or a task not requiring self-control. Subsequently, participants were exposed to palatable food, and effortful self-control was measured via heart rate variability (HRV). Restrained eating was associated with enhanced HRV during food exposure after exercising self-control but not after not exercising self-control. The results indicate that maintaining dieting goals results in food cues initiating effortful self-control after a preceding act of self-control. We suggest considering the effect of acts of self-control when modeling the initial steps on the path from food cues to unsuccessful restrained eating. Copyright © 2015 Elsevier Ltd. All rights reserved.
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.
Sartori, Marina R; Leite, Cleo A C; Abe, Augusto S; Crossley, Dane A; Taylor, Edwin W
The autonomic control of heart rate was studied throughout development in embryos of the green iguana, Iguana iguana by applying receptor agonists and antagonists of the parasympathetic and sympathetic systems. Acetylcholine (Ach) slowed or stopped the heart and atropine antagonized the response to Ach indicating the presence of muscarinic cholinoceptors on the heart of early embryos. However, atropine injections had no impact on heart rate until immediately before hatching, when it increased heart rate by 15%. This cholinergic tonus increased to 34% in hatchlings and dropped to 24% in adult iguanas. Although epinephrine was without effect, injection of propranolol slowed the heart throughout development, indicating the presence of β-adrenergic receptors on the heart of early embryos, possibly stimulated by high levels of circulating catecholamines. The calculated excitatory tonus varied between 33% and 68% until immediately before hatching when it fell to 25% and 29%, a level retained in hatchlings and adults. Hypoxia caused a bradycardia in early embryos that was unaffected by injection of atropine indicating that hypoxia has a direct effect upon the heart. In later embryos and hatchlings hypoxia caused a tachycardia that was unaffected by injection of atropine. Subsequent injection of propranolol reduced heart rate both uncovering a hypoxic bradycardia in late embryos and abolishing tachycardia in hatchlings. Hypercapnia was without effect on heart rate in late stage embryos and in hatchlings. Copyright © 2015 Elsevier Inc. All rights reserved.
Full Text Available Helen E Ritchie,1 Carolina Ragnerstam,2 Elin Gustafsson,2 Johanna M Jonsson,2 William S Webster2 1Discipline of Biomedical Science, Sydney Medical School, University of Sydney, Lidcombe, 2Department of Anatomy and Histology, Sydney Medical School, University of Sydney, Sydney, NSW, Australia Abstract: The aim of this study was to gain insight into whether the first trimester embryo could control its own heart rate (HR in response to hypoxia. The gestational day 13 rat embryo is a good model for the human embryo at 5–6 weeks gestation, as the heart is comparable in development and, like the human embryo, has no functional autonomic nerve supply at this stage. Utilizing a whole-embryo culture technique, we examined the effects of different pharmacological agents on HR under normoxic (95% oxygen and hypoxic (20% oxygen conditions. Oxygen concentrations ≤60% caused a concentration-dependent decrease in HR from normal levels of ~210 bpm. An adenosine agonist, AMP-activated protein kinase (AMPK activator and KATP channel opener all caused bradycardia in normoxic conditions; however, putative antagonists for these systems failed to prevent or ameliorate hypoxia-induced bradycardia. This suggests that the activation of one or more of these systems is not the primary cause of the observed hypoxia-induced bradycardia. Inhibition of oxidative phosphorylation also decreased HR in normoxic conditions, highlighting the importance of ATP levels. The β-blocker metoprolol caused a concentration-dependent reduction in HR supporting reports that β1-adrenergic receptors are present in the early rat embryonic heart. The cAMP inducer colforsin induced a positive chronotropic effect in both normoxic and hypoxic conditions. Overall, the embryonic HR at this stage of development is responsive to the level of oxygenation, probably as a consequence of its influence on ATP production. Keywords: embryonic heart rate, embryo, bradycardia, in vitro, ATP, hypoxia
Fu, M; Ahrenmark, U; Berglund, S; Lindholm, C J; Lehto, A; Broberg, A Månsson; Tasevska-Dinevska, G; Wikstrom, G; Ågard, A; Andersson, B
Despite that heart rate (HR) control is one of the guideline-recommended treatment goals for heart failure (HF) patients, implementation has been painstakingly slow. Therefore, it would be important to identify patients who have not yet achieved their target heart rates and assess possible underlying reasons as to why the target rates are not met. The survey of HR in patients with HF in Sweden (HR-HF survey) is an investigator-initiated, prospective, multicenter, observational longitudinal study designed to investigate the state of the art in the control of HR in HF and to explore potential underlying mechanisms for suboptimal HR control with focus on awareness of and adherence to guidelines for HR control among physicians who focus on the contributing role of beta-blockers (BBs). In 734 HF patients the mean HR was 68 ± 12 beats per minute (bpm) (37.2% of the patients had a HR >70 bpm). Patients with HF with reduced ejection fraction (HFrEF) (n = 425) had the highest HR (70 ± 13 bpm, with 42% >70 bpm), followed by HF with preserved ejection fraction and HF with mid-range ejection fraction. Atrial fibrillation, irrespective of HF type, had higher HR than sinus rhythm. A similar pattern was observed with BB treatment. Moreover, non-achievement of the recommended target HR (70 bpm optimal and an equal number considered a HR of >70 bpm too high, but without recommending further action. Furthermore, suboptimal HR control cannot be attributed to the use of BBs because there was neither a difference in use of BBs nor an interaction with BBs for HR >70 bpm compared with HR HF care.
Horne, Rosemary S C; Fyfe, Karinna L; Odoi, Alexsandria; Athukoralage, Anjalee; Yiallourou, Stephanie R; Wong, Flora Y
Preterm infants are at increased risk of sudden infant death syndrome (SIDS). Use of a dummy/pacifier is thought to be protective against SIDS; accordingly, we assessed the effects of dummy/pacifier use on blood pressure, cerebral oxygenation, and heart rate control over the first 6 mo of life after term corrected age (CA) when SIDS risk is greatest. Thirty-five preterm infants were studied longitudinally at 2-4 wk, 2-3 mo, and 5-6 mo CA. Cardiac control was assessed from spectral indices of heart rate variability (HRV) in the low frequency (LF) and the high frequency (HF) range, and the ratio of HF/LF indicating sympathovagal balance was calculated. Overall, at 2-3 mo, mean arterial pressure was significantly higher in the supine position in dummy/pacifier users in both quiet sleep (70 ± 2 vs. 60 ± 2 mm Hg; P preterm infants.
Nageotte, Michael P
Electronic fetal heart rate monitoring is a widely utilized means of assessment of fetal status during labor. Whereas little evidence exists regarding efficacy, this modality continues to be used extensively in every modern labor and delivery unit in developed countries. It is of importance that all providers of health care to the woman in labor and her newborn have a clear understanding of the basic pathophysiology of fetal heart rate monitoring and an appreciation for labor course and concerns as they arise in order to optimize outcomes and patient safety. Copyright © 2015 Elsevier Ltd. All rights reserved.
... Venous Thromboembolism Aortic Aneurysm More Blood Pressure vs. Heart Rate (Pulse) Updated:Sep 15,2017 Understanding the difference ... your blood moving through your blood vessels, your heart rate is the number of times your heart beats ...
Höglund, Odd Viking; Lövebrant, Johanna; Olsson, Ulf; Höglund, Katja
Surgery causes a stress response, a physiologic response to trauma. The intraoperative surgical stress response in dogs diagnosed with pyometra has not previously been described. The aim of this study was to investigate the intraoperative surgical stress response, assessed by blood pressure and heart rate measurements, in dogs diagnosed with pyometra and healthy controls. All dogs were premedicated with acepromazine and methadone, anaesthesia was induced with propofol and maintained with isoflurane, where after the dogs were subjected to ovariohysterectomy. Eight dogs diagnosed with pyometra and eight healthy controls were used. Systolic blood pressure and heart rate were measured to assess the surgical stress response. Additionally propofol dosage at induction of anaesthesia and the end-tidal isoflurane concentration were investigated. The surgery was split into four phases. Phase 0 was the period 10 min before the skin incision, phase 1 was skin incision and opening of abdomen, phase 2 was manipulation of uterine horns, lifting of the ovary with stretching of the mesovarium, ligation and transection of mesovarium and phase 3 was ligation and transection of cervix, removal of organs and closing of the abdomen. Dosage of propofol at induction of anaesthesia was 3.6 ± 1 mg/kg in dogs with pyometra and 4.1 ± 1 in healthy controls (P = 0.37). In both groups, systolic blood pressure increased between phase 1 and 2, from 87 ± 15 to 114 ± 19 mmHg in dogs with pyometra, and from 88 ± 18 to 106 ± 20 mmHg in healthy controls, (both P pyometra and healthy controls.
Chao, C.F.; Ting, L.; Subjeck, J.R.; Johnson, R.J.
The neurotoxic effect of the nitroimidazole radiosensitizers misonidazole (MISO) and desmethylmisonidazole (DMM) has seriously compromised their clinical effectiveness. The authors compare here the effect of MISO and DMM on oxygen consumption in purified beef heart mitochondria. MISO has been found to significantly increase the oxygen consumption rate and decrease the respiratory control ratio in isolated mitochondria when incubated in the presence of the NAD+ dependent substrate, ..beta..-hydroxybutyrate. DMM has a similar but less pronounced effect than MISO on these respiratory parameters. When mitochondria were incubated in the presence of these radiosensitizers for 8, 15, 30, 45, and 60 minutes, the oxygen consumption rate was decreased when succinate, a FAD dependent substrate, was added following the incubation. This decrease, which is both time and dosage dependent, is equivalent for MISO and DMM.
Hughson, R. L.; Shoemaker, J. K.; Blaber, A. P.; Arbeille, Ph.; Zuj, K. A.; Greaves, D. K.
CCISS is a project to study the cardiovascular and cerebrovascular responses of astronauts before, during and after long-duration (>60-day) stays on the International Space Station. The CCISS experiments consist of three phases that are designed to achieve an integrated examination of components responsible for return of blood to the heart, the pumping of blood from the heart and the distribution to the vascular territories including the brain. In this report the data are obtained from the 24-h monitoring of physical activity (Actiwatch on wrist and ankle) and of heart rate (Holter monitor). The data show clear patterns of change in physical activity from predominantly leg-based on Earth to relatively little activity of the ankles with maintained or increased activity of the wrists on ISS. Both on Earth and on ISS the largest changes in heart rate occur during the periods of leg activity. Average heart rate was changed little during the periods of minimal activity or of sleep in comparisons of Earth with in-flight recording both within the first two weeks of flight and the last two weeks. These data clearly show the importance of monitoring heart rate and physical activity simultaneously and show that attempts to derive indicators of autonomic activity from spectral analysis of heart rate variability should not be performed in the absence of knowledge of both variables.
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.
Zakynthinaki, Maria S.
The objective of the present study was to formulate a simple and at the same time effective mathematical model of heart rate kinetics in response to movement (exercise). Based on an existing model, a system of two coupled differential equations which give the rate of change of heart rate and the rate of change of exercise intensity is used. The modifications introduced to the existing model are justified and discussed in detail, while models of blood lactate accumulation in respect to time and exercise intensity are also presented. The main modification is that the proposed model has now only one parameter which reflects the overall cardiovascular condition of the individual. The time elapsed after the beginning of the exercise, the intensity of the exercise, as well as blood lactate are also taken into account. Application of the model provides information regarding the individual’s cardiovascular condition and is able to detect possible changes in it, across the data recording periods. To demonstrate examples of successful numerical fit of the model, constant intensity experimental heart rate data sets of two individuals have been selected and numerical optimization was implemented. In addition, numerical simulations provided predictions for various exercise intensities and various cardiovascular condition levels. The proposed model can serve as a powerful tool for a complete means of heart rate analysis, not only in exercise physiology (for efficiently designing training sessions for healthy subjects) but also in the areas of cardiovascular health and rehabilitation (including application in population groups for which direct heart rate recordings at intense exercises are not possible or not allowed, such as elderly or pregnant women). PMID:25876164
van der Zwan, Judith Esi; de Vente, Wieke; Huizink, Anja C; Bögels, Susan M; de Bruin, Esther I
In contemporary western societies stress is highly prevalent, therefore the need for stress-reducing methods is great. This randomized controlled trial compared the efficacy of self-help physical activity (PA), mindfulness meditation (MM), and heart rate variability biofeedback (HRV-BF) in reducing stress and its related symptoms. We randomly allocated 126 participants to PA, MM, or HRV-BF upon enrollment, of whom 76 agreed to participate. The interventions consisted of psycho-education and an introduction to the specific intervention techniques and 5 weeks of daily exercises at home. The PA exercises consisted of a vigorous-intensity activity of free choice. The MM exercises consisted of guided mindfulness meditation. The HRV-BF exercises consisted of slow breathing with a heart rate variability biofeedback device. Participants received daily reminders for their exercises and were contacted weekly to monitor their progress. They completed questionnaires prior to, directly after, and 6 weeks after the intervention. Results indicated an overall beneficial effect consisting of reduced stress, anxiety and depressive symptoms, and improved psychological well-being and sleep quality. No significant between-intervention effect was found, suggesting that PA, MM, and HRV-BF are equally effective in reducing stress and its related symptoms. These self-help interventions provide easily accessible help for people with stress complaints.
Quintana, D S; Westlye, L T; Kaufmann, T; Rustan, Ø G; Brandt, C L; Haatveit, B; Steen, N E; Andreassen, O A
Despite current diagnostic systems distinguishing schizophrenia (SZ) and bipolar disorder (BD) as separate diseases, emerging evidence suggests they share a number of clinical and epidemiological features, such as increased cardiovascular disease (CVD) risk. It is not well understood if poor cardiac autonomic nervous system regulation, which can be indexed non-invasively by the calculation of heart rate variability (HRV), contributes to these common CVD risk factors in both diseases. We calculated HRV in 47 patients with SZ, 33 patients with BD and 212 healthy controls. Measures of symptom severity were also collected from the patient groups. Heart rate variability was significantly reduced in both these disorders in comparison with the healthy participants; however, there were no HRV differences between disorders. Importantly, these reductions were independent of the medication, age or body mass index effects. There was also preliminary evidence that patients with reduced HRV had increased overall and negative psychosis symptom severity regardless of SZ or BD diagnosis. We suggest that HRV may provide a possible biomarker of CVD risk and symptom severity in severe mental illness. Thus, our results highlight the importance of cardiometabolic screening across SZ and bipolar spectrum disorders. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
... is your level of intensity? When is the best time of day to work out? Target Heart Rates Warm Up, Cool Down See More >> Getting Active Getting Started - Tips for Long-term Exercise Success Get Moving: Easy Tips to Get Active! ...
de Vries, S T; Komdeur, P; Aalbersberg, S; van Enst, G C; Breeman, A; van 't Hof, A W J
Background. To evaluate the safety and effects of high altitude on exercise level and heart rate in patients with coronary artery disease compared with healthy controls.Methods. Eight patients with a history of an acute myocardial infarction (ejection fraction >5%) with a low-risk score were compared with seven healthy subjects during the Dutch Heart Expedition at the Aconcagua in Argentina in March 2007. All subjects underwent a maximum exercise test with a cycle ergometer at sea level and base camp, after ten days of acclimatisation, at an altitude of 4200 m. Exercise capacity and maximum heart rate were compared between groups and within subjects.Results. There was a significant decrease in maximum heart rate at high altitude compared with sea level in both the patient and the control group (166 vs. 139 beats/min, pheart rate between patients and healthy controls (-31 vs. -30%, p=0.673).Conclusion. Both patients and healthy controls showed a similar decrease in exercise capacity and maximum heart rate at 4200 m compared with sea level, suggesting that patients with a history of coronary artery disease may tolerate stay and exercise at high altitude similarly to healthy controls. (Neth Heart J 2010;18:118-21.).
Masuki, Shizue; Eisenach, John H; Schrage, William G; Dietz, Niki M; Johnson, Christopher P; Wilkins, Brad W; Dierkhising, Ross A; Sandroni, Paola; Low, Phillip A; Joyner, Michael J
Patients with postural tachycardia syndrome (POTS) have excessive tachycardia without hypotension during orthostasis as well as exercise. We tested the hypothesis that excessive tachycardia during exercise in POTS is not related to abnormal baroreflex control of heart rate (HR). Patients (n = 13) and healthy controls (n = 10) performed graded cycle exercise at 25, 50, and 75 W in both supine and upright positions while arterial pressure (arterial catheter) and HR (ECG) were measured. Baroreflex sensitivity of HR was assessed by bolus intravenous infusion of phenylephrine at each workload. In both positions, HR was higher in the patients than the controls during exercise. Supine baroreflex sensitivity (HR/systolic pressure) in POTS patients was -1.3 +/- 0.1 beats.min(-1).mmHg(-1) at rest and decreased to -0.6 +/- 0.1 beats.min(-1).mmHg(-1) during 75-W exercise, neither significantly different from the controls (P > 0.6). In the upright position, baroreflex sensitivity in POTS patients at rest (-1.4 +/- 0.1 beats.min(-1).mmHg(-1)) was higher than the controls (-1.0 +/- 0.1 beats.min(-1).mmHg(-1)) (P pulse pressure in the patients than in the controls with 56 and 90% higher coefficient of variations, respectively (P tachycardia during exercise in POTS was not due to abnormal baroreflex control of HR.
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Weippert, Matthias; Behrens, Martin; Mau-Moeller, Anett; Bruhn, Sven; Behrens, Kristin
During cycling before (PRE) and after exhaustion (POST) different modes of autonomic cardiac control might occur due to different interoceptive input and altered influences from higher brain centers. We hypothesized that heart rate variability (HRV) is significantly affected by an interaction of the experimental period (PRE vs. POST) and exercise intensity (HIGH vs. LOW; HIGH = HR > HR at the lactate threshold (HR LT ), LOW = HR ≤ HR LT ) despite identical average HR. Methods: Fifty healthy volunteers completed an incremental cycling test until exhaustion. Workload started with 30 W at a constant pedaling rate (60 revolutions · min -1 ) and was gradually increased by 30 W · 5 min -1 . Five adjacent 60 s inter-beat (R-R) interval segments from the immediate recovery period (POST 1-5 at 30 W and 60 rpm) were each matched with their HR-corresponding 60 s-segments during the cycle test (PRE 1-5). An analysis of covariance was carried out with one repeated-measures factor (PRE vs. POST exhaustion), one between-subject factor (HIGH vs. LOW intensity) and respiration rate as covariate to test for significant effects ( p exhaustion at HIGH intensity. On the opposite, at LOW intensity cycling, a stronger coactivational cardiac autonomic modulation pattern occurs during PRE-exhaustion if compared to POST-exhaustion cycling. The different autonomic modes during these phases might be the result of different afferent and/or central inputs to the cardiovascular control centers in the brainstem.
Södervall, Jarmo; Karppinen, Jaro; Puolitaival, Jukka; Kyllönen, Eero; Kiviniemi, Antti M; Tulppo, Mikko P; Hautala, Arto J
A chronic pain condition may result in altered autonomic nervous system regulation in various patient populations. We evaluated whether autonomic regulation differs between sciatica patients referred to spine surgery and age-matched healthy controls analyzed with heart rate variability techniques (HRV). HRV of patients (n = 201) and healthy controls (n = 138) were measured in standing conditions (5 min). High frequency (HF) power as an index of cardiac vagal modulation and the low-to-high-frequency (LF/HF) ratio and short-term fractal scaling exponent α1 as indices of sympathovagal balance were analyzed. Pain intensity was assessed on a Visual Analog Scale (VAS) and perceived disability with Oswestry Disability Index. The Oswestry and VAS scores were higher in the patients than in the controls (p Sciatica patients referred to spine surgery had altered cardiac autonomic regulation expressed as decreased vagal activity and an increased sympathovagal balance toward sympathetic dominance when compared with age-matched healthy controls.
Chu, I-Hua; Wu, Wen-Lan; Lin, I-Mei; Chang, Yu-Kai; Lin, Yuh-Jen; Yang, Pin-Chen
The purpose of the study was to investigate the effects of a 12-week yoga program on heart rate variability (HRV) and depressive symptoms in depressed women. This was a randomized controlled trial. Twenty-six sedentary women scoring ≥14 on the Beck Depression Inventory-II were randomized to either the yoga or the control group. The yoga group completed a 12-week yoga program, which took place twice a week for 60 min per session and consisted of breathing exercises, yoga pose practice, and supine meditation/relaxation. The control group was instructed not to engage in any yoga practice and to maintain their usual level of physical activity during the course of the study. Participants' HRV, depressive symptoms, and perceived stress were assessed at baseline and post-test. The yoga group had a significant increase in high-frequency HRV and decreases in low-frequency HRV and low frequency/high frequency ratio after the intervention. The yoga group also reported significantly reduced depressive symptoms and perceived stress. No change was found in the control group. A 12-week yoga program was effective in increasing parasympathetic tone and reducing depressive symptoms and perceived stress in women with elevated depressive symptoms. Regular yoga practice may be recommended for women to cope with their depressive symptoms and stress and to improve their HRV.
Gijsbers, L.; Molenberg, Famke; Bakker, S.J.L.; Geleijnse, J.M.
Background and aims: Increasing the intake of potassium has been shown to lower blood pressure, but whether it also affects heart rate (HR) is largely unknown. We therefore assessed the effect of potassium supplementation on HR in a meta-analysis of randomized controlled trials. Methods and
Laurie L. Baggio
Conclusions: GLP-1R agonists increase HR through multiple mechanisms, including regulation of autonomic nervous system function, and activation of the atrial GLP-1R. Surprisingly, the isolated atrial GLP-1R does not transduce a direct chronotropic effect following exposure to GLP-1R agonists in the intact heart, or isolated atrium, ex vivo. Hence, cardiac GLP-1R circuits controlling HR require neural inputs and do not function in a heart-autonomous manner.
Graudal, Niels A; Hubeck-Graudal, Thorbjørn; Jürgens, Gesche
.... As heart rate is independently associated with the development of heart failure and increased risk of premature death a potential increase in heart rate could be a harmful side-effect of sodium reduction...
Graudal, Niels A; Hubeck-Graudal, Thorbjørn; Jürgens, Gesche
Reduced dietary sodium intake (sodium reduction) increases heart rate in some studies of animals and humans. As heart rate is independently associated with the development of heart failure and increased risk of premature death a potential increase in heart rate could be a harmful side......-effect of sodium reduction. The purpose of the present meta-analysis was to investigate the effect of sodium reduction on heart rate. Relevant studies were retrieved from an updated pool of 176 randomized controlled trials (RCTs) published in the period 1973-2014. Sixty-three of the RCTs including 72 study...... populations reported data on heart rate. In a meta-analysis of these data sodium reduction increased heart rate with 1.65 beats per minute [95% CI: 1.19, 2.11], p heart rate. This effect was independent of baseline blood pressure. In conclusion sodium reduction...
Karppinen, S; Rapila, R; Mäkikallio, K; Hänninen, S L; Rysä, J; Vuolteenaho, O; Tavi, P
Spontaneous activity of embryonic cardiomyocytes originates from sarcoplasmic reticulum (SR) Ca(2+) release during early cardiogenesis. However, the regulation of heart rate during embryonic development is still not clear. The aim of this study was to determine how endothelin-1 (ET-1) affects the heart rate of embryonic mice, as well as the pathway through which it exerts its effects. The effects of ET-1 and ET-1 receptor inhibition on cardiac contraction were studied using confocal Ca(2+) imaging of isolated mouse embryonic ventricular cardiomyocytes and ultrasonographic examination of embryonic cardiac contractions in utero. In addition, the amount of ET-1 peptide and ET receptor a (ETa) and b (ETb) mRNA levels were measured during different stages of development of the cardiac muscle. High ET-1 concentration and expression of both ETa and ETb receptors was observed in early cardiac tissue. ET-1 was found to increase the frequency of spontaneous Ca(2+) oscillations in E10.5 embryonic cardiomyocytes in vitro. Non-specific inhibition of ET receptors with tezosentan caused arrhythmia and bradycardia in isolated embryonic cardiomyocytes and in whole embryonic hearts both in vitro (E10.5) and in utero (E12.5). ET-1-mediated stimulation of early heart rate was found to occur via ETb receptors and subsequent inositol trisphosphate receptor activation and increased SR Ca(2+) leak. Endothelin-1 is required to maintain a sufficient heart rate, as well as to prevent arrhythmia during early development of the mouse heart. This is achieved through ETb receptor, which stimulates Ca(2+) leak through IP3 receptors. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.
Silva, Luiz Eduardo Virgilio; Silva, Carlos Alberto Aguiar; Salgado, Helio Cesar; Fazan, Rubens
Analysis of heart rate variability (HRV) by nonlinear approaches has been gaining interest due to their ability to extract additional information from heart rate (HR) dynamics that are not detectable by traditional approaches. Nevertheless, the physiological interpretation of nonlinear approaches remains unclear. Therefore, we propose long-term (60 min) protocols involving selective blockade of cardiac autonomic receptors to investigate the contribution of sympathetic and parasympathetic function upon nonlinear dynamics of HRV. Conscious male Wistar rats had their electrocardiogram (ECG) recorded under three distinct conditions: basal, selective (atenolol or atropine), or combined (atenolol plus atropine) pharmacological blockade of autonomic muscarinic or β1-adrenergic receptors. Time series of RR interval were assessed by multiscale entropy (MSE) and detrended fluctuation analysis (DFA). Entropy over short (1 to 5, MSE1-5) and long (6 to 30, MSE6-30) time scales was computed, as well as DFA scaling exponents at short (αshort, 5 ≤ n ≤ 15), mid (αmid, 30 ≤ n ≤ 200), and long (αlong, 200 ≤ n ≤ 1,700) window sizes. The results show that MSE1-5 is reduced under atropine blockade and MSE6-30 is reduced under atropine, atenolol, or combined blockade. In addition, while atropine expressed its maximal effect at scale six, the effect of atenolol on MSE increased with scale. For DFA, αshort decreased during atenolol blockade, while the αmid increased under atropine blockade. Double blockade decreased αshort and increased αlong Results with surrogate data show that the dynamics during combined blockade is not random. In summary, sympathetic and vagal control differently affect entropy (MSE) and fractal properties (DFA) of HRV. These findings are important to guide future studies.NEW & NOTEWORTHY Although multiscale entropy (MSE) and detrended fluctuation analysis (DFA) are recognizably useful prognostic/diagnostic methods, their physiological
Iliescu, Radu; Tudorancea, Ionut; Irwin, Eric D; Lohmeier, Thomas E
The sensitivity of baroreflex control of heart rate is depressed in subjects with obesity hypertension, which increases the risk for cardiac arrhythmias. The mechanisms are not fully known, and there are no therapies to improve this dysfunction. To determine the cardiovascular dynamic effects of progressive increases in body weight leading to obesity and hypertension in dogs fed a high-fat diet, 24-h continuous recordings of spontaneous fluctuations in blood pressure and heart rate were analyzed in the time and frequency domains. Furthermore, we investigated whether autonomic mechanisms stimulated by chronic baroreflex activation and renal denervation-current therapies in patients with resistant hypertension, who are commonly obese-restore cardiovascular dynamic control. Increases in body weight to ∼150% of control led to a gradual increase in mean arterial pressure to 17 ± 3 mmHg above control (100 ± 2 mmHg) after 4 wk on the high-fat diet. In contrast to the gradual increase in arterial pressure, tachycardia, attenuated chronotropic baroreflex responses, and reduced heart rate variability were manifest within 1-4 days on high-fat intake, reaching 130 ± 4 beats per minute (bpm) (control = 86 ± 3 bpm) and ∼45% and heart rate variability. These findings suggest that baroreflex activation therapy may reduce the risk factors for cardiac arrhythmias as well as lower arterial pressure.
Iliescu, Radu; Tudorancea, Ionut; Irwin, Eric D.
The sensitivity of baroreflex control of heart rate is depressed in subjects with obesity hypertension, which increases the risk for cardiac arrhythmias. The mechanisms are not fully known, and there are no therapies to improve this dysfunction. To determine the cardiovascular dynamic effects of progressive increases in body weight leading to obesity and hypertension in dogs fed a high-fat diet, 24-h continuous recordings of spontaneous fluctuations in blood pressure and heart rate were analyzed in the time and frequency domains. Furthermore, we investigated whether autonomic mechanisms stimulated by chronic baroreflex activation and renal denervation—current therapies in patients with resistant hypertension, who are commonly obese—restore cardiovascular dynamic control. Increases in body weight to ∼150% of control led to a gradual increase in mean arterial pressure to 17 ± 3 mmHg above control (100 ± 2 mmHg) after 4 wk on the high-fat diet. In contrast to the gradual increase in arterial pressure, tachycardia, attenuated chronotropic baroreflex responses, and reduced heart rate variability were manifest within 1–4 days on high-fat intake, reaching 130 ± 4 beats per minute (bpm) (control = 86 ± 3 bpm) and ∼45% and hypertension. However, only baroreflex activation effectively attenuated the tachycardia and restored cardiac baroreflex sensitivity and heart rate variability. These findings suggest that baroreflex activation therapy may reduce the risk factors for cardiac arrhythmias as well as lower arterial pressure. PMID:23913707
Pieringer, Herwig; Brummaier, Tobias; Schmid, Michael; Pichler, Max; Hayat-Khayyati, Avida; Ebner, Stefan; Biesenbach, Georg; Pohanka, Erich
Rheumatoid arthritis (RA) is associated with increased cardiovascular morbidity and mortality. In the general population, an increased heart rate is associated with increased mortality. Only a few studies have investigated heart rate in RA patients and compared the results with patients that do not have RA (n-RA). Therefore, little is known as to whether an increased heart rate, at least in part, could explain the increased mortality found in RA patients. The aim of the present study was to investigate whether heart rate is increased in RA patients. In this cross-sectional study, heart rate was determined in a total of 282 patients (131 RA, 151 n-RA). In addition, non-invasive pulse wave analysis of the radial artery was performed to determine cardiac ejection duration using the Sphygmocor apparatus. Furthermore, the subendocardial viability ratio (SEVR), a marker of cardiac workload, was investigated, whereby higher values indicate a more favorable supply/demand relationship for the myocardium. Patients using chronotropic drugs were not included in the study. Heart rate was virtually the same in RA patients (71.9 ± 11.2 beats/min [bpm]) as compared with controls (72.3 ± 11.7 bpm; P > 0.05). Also SEVR (RA 144 ± 25% vs. n-RA 147 ± 27%; P > 0.05) and ejection duration (RA 321 ± 24 ms vs. n-RA 318 ± 24 ms; P > 0.05) were comparable between the groups. It could not be shown that heart rate in RA patients differs significantly from heart rate in controls. Therefore, heart rate does not appear to explain or contribute to the increased cardiovascular risk found in RA patients. © 2013 The Authors International Journal of Rheumatic Diseases © 2013 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.
Full Text Available During cycling before (PRE and after exhaustion (POST different modes of autonomic cardiac control might occur due to different interoceptive input and altered influences from higher brain centers. We hypothesized that heart rate variability (HRV is significantly affected by an interaction of the experimental period (PRE vs. POST and exercise intensity (HIGH vs. LOW; HIGH = HR > HR at the lactate threshold (HRLT, LOW = HR ≤ HRLT despite identical average HR.Methods: Fifty healthy volunteers completed an incremental cycling test until exhaustion. Workload started with 30 W at a constant pedaling rate (60 revolutions · min−1 and was gradually increased by 30 W · 5 min−1. Five adjacent 60 s inter-beat (R-R interval segments from the immediate recovery period (POST 1–5 at 30 W and 60 rpm were each matched with their HR-corresponding 60 s-segments during the cycle test (PRE 1–5. An analysis of covariance was carried out with one repeated-measures factor (PRE vs. POST exhaustion, one between-subject factor (HIGH vs. LOW intensity and respiration rate as covariate to test for significant effects (p < 0.050 on the natural log-transformed root mean square of successive differences between adjacent R-R intervals (lnRMSSD60s.Results: LnRMSSD60s was significantly affected by the interaction of experimental period × intensity [F(1, 242 = 30.233, p < 0.001, ηp2 = 0.111]. LnRMSSD60s was higher during PRE compared to POST at LOW intensity (1.6 ± 0.6 vs. 1.4 ± 0.6 ms; p < 0.001. In contrast, at HIGH intensity lnRMSSD60s was lower during PRE compared to POST (1.0 ± 0.4 vs. 1.2 ± 0.4 ms; p < 0.001.Conclusion: Identical net HR during cycling can result from distinct autonomic modulation patterns. Results suggest a pronounced sympathetic-parasympathetic coactivation immediately after the cessation of peak workload compared to HR-matched cycling before exhaustion at HIGH intensity. On the opposite, at LOW intensity cycling, a stronger coactivational
... tachycardia occurs less commonly with: Heart attack Serious mitral valve disease Symptoms and Complications of Atrial or SVT Some ... tachycardia occurs less commonly with: Heart attack Serious mitral valve disease Symptoms and Complications of Atrial or SVT Some ...
do Prado, Dm Leite; Gualano, B; Miossi, R; Sá-Pinto, Al; Lima, Fr; Roschel, H; Borba, Ef; Bonfá, E
Abnormal heart-rate (HR) response during or after a graded exercise test has been recognized as a strong and an independent predictor of all-cause mortality in healthy and diseased subjects. The purpose of the present study was to evaluate the HR response during exercise in women with systemic lupus erythematosus (SLE). In this case-control study, 22 women with SLE (age 29.5 ± 1.1 years) were compared with 20 gender-, BMI-, and age-matched healthy subjects (age 26.5 ± 1.4 years). A treadmill cardiorespiratory test was performed and HR response during exercise was evaluated by the chronotropic reserve (CR). HR recovery (ΔHRR) was defined as the difference between HR at peak exercise and at both first (ΔHRR1) and second (ΔHRR2) minutes after exercising. SLE patients presented lower peak VO(2) when compared with healthy subjects (27.6 ± 0.9 vs. 36.7 ± 1.1 ml/kg/min, p = 0.001, respectively). Additionally, SLE patients demonstrated lower CR (71.8 ± 2.4 vs. 98.2 ± 2.6%, p = 0.001), ΔHRR1 (22.1 ± 2.5 vs. 32.4 ± 2.2%, p = 0.004) and ΔHRR2 (39.1 ± 2.9 vs. 50.8 ± 2.5%, p = 0.001) than their healthy peers. In conclusion, SLE patients presented abnormal HR response to exercise, characterized by chronotropic incompetence and delayed ΔHRR.
Variations of high frequency parameter of heart rate variability following osteopathic manipulative treatment in healthy subjects compared to control group and sham therapy: randomized controlled trial
Nuria eRuffini; Giandomenico eD'alessandro; Nicolò eMariani; Alberto ePollastrelli; Lucia eCardinali; Francesco eCerritelli
Context: Heart Rate Variability (HRV) indicates how heart rate changes in response to inner and external stimuli. HRV is linked to health status and it is an indirect marker of the autonomic nervous system (ANS) function. Objective: To investigate the influence of osteopathic manipulative treatment (OMT) on cardiac autonomic modulation in healthy subjects, compared with sham therapy and control group. Methods: Sixty-six healthy subjects, both male and female, were included in the present 3-ar...
Full Text Available Ana Isabel Penzlin,1 Timo Siepmann,2 Ben Min-Woo Illigens,3 Kerstin Weidner,4 Martin Siepmann4 1Institute of Clinical Pharmacology, 2Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Saxony, Germany; 3Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; 4Department of Psychotherapy and Psychosomatic Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Saxony, Germany Background and objective: In patients with alcohol dependence, ethyl-toxic damage of vasomotor and cardiac autonomic nerve fibers leads to autonomic imbalance with neurovascular and cardiac dysfunction, the latter resulting in reduced heart rate variability (HRV. Autonomic imbalance is linked to increased craving and cardiovascular mortality. In this study, we sought to assess the effects of HRV biofeedback training on HRV, vasomotor function, craving, and anxiety. Methods: We conducted a randomized controlled study in 48 patients (14 females, ages 25–59 years undergoing inpatient rehabilitation treatment. In the treatment group, patients (n=24 attended six sessions of HRV biofeedback over 2 weeks in addition to standard rehabilitative care, whereas, in the control group, subjects received standard care only. Psychometric testing for craving (Obsessive Compulsive Drinking Scale, anxiety (Symptom Checklist-90-Revised, HRV assessment using coefficient of variation of R-R intervals (CVNN analysis, and vasomotor function assessment using laser Doppler flowmetry were performed at baseline, immediately after completion of treatment or control period, and 3 and 6 weeks afterward (follow-ups 1 and 2. Results: Psychometric testing showed decreased craving in the biofeedback group immediately postintervention (OCDS scores: 8.6±7.9 post-biofeedback versus 13.7±11.0 baseline [mean ± standard deviation], P<0.05, whereas craving was unchanged at
Kumarathurai, Preman; Anholm, Christian; Larsen, Bjørn Strøier
OBJECTIVE: Reduced heart rate variability (HRV) and increased heart rate (HR) have been associated with cardiovascular mortality. Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) increase HR, and studies have suggested that they may reduce HRV. We examined the effect of the GLP-1 RA...
Full Text Available Neurotransmitters released from sympathetic and parasympathetic nerve terminals in the SAN exert their effects via G-protein-coupled receptors. Integration of these different G-protein signals within pacemaker cells of the sinoatrial node (SAN is critical for proper regulation of heart rate and function. For example, excessive parasympathetic signaling can be associated with sinus node dysfunction and supraventricular arrhythmias. Our previous work has shown that one member of the regulator of G-protein signaling (RGS protein family, RGS4, is highly and selectively expressed in pacemaker cells of the SAN. Consistent with its role as an inhibitor of parasympathetic signaling, RGS4-knockout mice have reduced basal heart rates and enhanced negative chronotropic responses to parasympathetic agonists. Moreover, RGS4 appears to be an important part of SA nodal myocyte signaling pathways that mediate G protein-coupled inwardly-rectifying potassium channel (GIRK channel activation/deactivation and desensitization. Since RGS4 acts immediately downstream of M2 muscarinic receptors, it is tempting to speculate that RGS4 functions as a master regulator of parasympathetic signaling upstream of GIRKs, HCNs and L-type Ca2+ channels in the SAN. Thus, loss of RGS4 function may lead to increased susceptibility to conditions associated with increased parasympathetic signaling, including bradyarrhythmia, sinus node dysfunction, and atrial fibrillation.
Mulder, Bart A.; Van Veldhuisen, Dirk J.; Crijns, Harry J. G. M.; Tijssen, Jan G. P.; Hillege, Hans L.; Alings, Marco; Rienstra, Michel; Groenveld, Hessel F.; Van den Berg, Maarten P.; Van Gelder, Isabelle C.
AIMS: It is unknown whether lenient rate control is an acceptable strategy in patients with AF and heart failure. We evaluated differences in outcome in patients with AF and heart failure treated with lenient or strict rate control. METHODS AND RESULTS: This post-hoc analysis of the RACE II trial
De Schryver, Nicolas; Scavée, Christophe; Marchandise, Sébastien; Pasquet, Agnès; de Meester, Christophe; le Polain de Waroux, Jean-Benoît
Atrial fibrillation (AF) patients treated according to a rate-control strategy seem to have excellent outcomes as long as their ventricular response is kept low. However, the stringency of the rate control to adopt with pharmacologic agents is not clearly defined. In particular, the clinical importance of preserving a heart rate (HR) reserve (HRR) during exercise has not yet been investigated. We prospectively analysed the HR response profiles during exercise of 202 patients with permanent AF for whom a strict rate-control strategy was the preferred treatment option. Patients were asked to perform an exercise test on a cycle ergometer until exhaustion. The HRR was defined as the difference between the HR at peak exercise and the resting HR before exercise, divided by the resting HR. Patients were followed-up for at least 24 months or until death or hospitalization for heart failure. The mean resting HR was 80 ± 16 b.p.m. After a median follow-up period of 3 ± 1 years, 31 patients (15.3%) of our initial population (80% male, age 72 ± 12 years) presented either a hospitalization for heart failure (n = 13, 6.4%) or a death (n = 18, 8.9%). Using a univariate analysis, we found that these events correlated with a lower exercise capacity [hazard ratio, HR 0.98, 95% confidence interval, CI (0.96; 0.99), P heart failure was better in patients with a preserved HRR (HRR >40%, P rate-control strategy is associated with an increased risk of hospitalization for heart failure. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: firstname.lastname@example.org.
Peçanha, Tiago; Forjaz, Claudia Lucia de Moraes; Low, David Andrew
This study assessed the additive effects of passive heating and exercise on cardiac baroreflex sensitivity (cBRS) and heart rate variability (HRV). Twelve healthy young men (25±1 yrs, 23.8±0.5 kg/m(2)) randomly underwent two experimental sessions: heat stress (HS; whole-body heat stress using a tube-lined suit to increase core temperature by ~1°C) and normothermia (NT). Each session was composed of a: pre-intervention rest (REST1); HS or NT interventions; post-intervention rest (REST2); and 14 min of cycling exercise [7 min at 40%HRreserve (EX1) and 7 min at 60%HRreserve (EX2)]. Heart rate and finger blood pressure were continuously recorded. cBRS was assessed using the sequence (cBRSSEQ) and transfer function (cBRSTF) methods. HRV was assessed using the indices SDNN (standard deviation of RR intervals) and RMSSD (root mean square of successive RR intervals). cBRS and HRV were not different between sessions during EX1 and EX2 (i.e. matched heart rate conditions: EX1=116±3 vs. 114±3, EX2=143±4 vs. 142±3 bpm; but different workloads: EX1=50±9 vs. 114±8, EX2=106±10 vs. 165±8 Watts; for HS and NT, respectively; Pheart rates), cBRS and HRV were significantly reduced in HS (cBRSSEQ = 1.6±0.3 vs. 0.6±0.1 ms/mmHg, P<0.01; SDNN = 2.3±0.1 vs. 1.3±0.2 ms, P<0.01). In conclusion, in conditions matched by HR, the addition of heat stress to exercise does not affect cBRS and HRV. Alternatively, in workload-matched conditions, the addition of heat to exercise results in reduced cBRS and HRV compared to exercise in normothermia. Copyright © 2017, Journal of Applied Physiology.
Derella, Cassandra C; Aichele, Kristin R; Oakman, Joyann E; Cromwell, Christina M; Hill, Jessica A; Chavis, Lauren N; Perez, Avery N; Getty, Allyson K; Wisdo, Tia R; Feairheller, Deborah L
To compare the effects of personal protective equipment (PPE) weight on blood pressure (BP) and heart rate (HR), between volunteer firefighters (FF) and athletes. Athletes and FF were matched by body size and came to the lab twice for two treadmill tests. The "Regular" test was completed in normal fitness clothing, and PPE test was completed in full structural PPE with monitoring of HR assessment every minute and BP each stage. In the FF cohort, all submaximal HR and BP levels were different. HRmax and VO2max were also different (all P < 0.05). In athletes, HRmax was higher in Regular test than PPE. Future research should examine the effect of different PPE weights on HR and BP responses.
Feldman, David; Elton, Terry S; Menachemi, Doron M; Wexler, Randy K
David Feldman1, Terry S Elton2, Doron M Menachemi3, Randy K Wexler41Heart Failure/Transplant and VAD Programs, Minneapolis Heart Institute, Minneapolis, Minnesota, USA; 2Division of Pharmacology, College of Pharmacology, The Ohio State University, Columbus, Ohio, USA; 3Heart Failure Services, Edith Wolfson Medical Center, The Heart Institute, Sakler School of Medicine, Tel-Aviv University, Holon, Israel; 4Department of Clinical Family Medicine, The Ohio State University, Columbus, Ohio, USAAb...
Posokhova, Ekaterina; Ng, David; Opel, Aaisha; Masuho, Ikuo; Tinker, Andrew; Biesecker, Leslie G.; Wickman, Kevin; Martemyanov, Kirill A.
Normal heart function requires generation of a regular rhythm by sinoatrial pacemaker cells and the alteration of this spontaneous heart rate by the autonomic input to match physiological demand. However, the molecular mechanisms that ensure consistent periodicity of cardiac contractions and fine tuning of this process by autonomic system are not completely understood. Here we examined the contribution of the m2R-IKACh intracellular signaling pathway, which mediates the negative chronotropic effect of parasympathetic stimulation, to the regulation of the cardiac pacemaking rhythm. Using isolated heart preparations and single-cell recordings we show that the m2R-IKACh signaling pathway controls the excitability and firing pattern of the sinoatrial cardiomyocytes and determines variability of cardiac rhythm in a manner independent from the autonomic input. Ablation of the major regulator of this pathway, Rgs6, in mice results in irregular cardiac rhythmicity and increases susceptibility to atrial fibrillation. We further identify several human subjects with variants in the RGS6 gene and show that the loss of function in RGS6 correlates with increased heart rate variability. These findings identify the essential role of the m2R-IKACh signaling pathway in the regulation of cardiac sinus rhythm and implicate RGS6 in arrhythmia pathogenesis. PMID:24204714
Mehlsen, J; Pagh, K; Nielsen, J S
Heart rate responses to stepwise and periodic changes in lung volume were studied in seven young healthy males. Stepwise inspiration and expiration both resulted in an increase in heart rate followed by a rapid decrease in heart rate. The fastest heart rate was reached in 1.6 +/- 0.5 s and in 3.......6 +/- 1.4 s in response to inspiration and expiration, respectively (P less than 0.01). The slowest heart rate was reached in 4.8 +/- 1.0 s and in 7.6 +/- 1.9 s in response to inspiration and expiration, respectively (P less than 0.01). Following this biphasic change the heart rate returned to a steady...... level. The difference between the fastest and the slowest heart rates was significantly larger in response to inspiration (21.7 +/- 7.3 beats per minute) than in response to expiration (12.0 +/- 7.3 beats per minute; P less than 0.01). Periodic changes in lung volume were performed with frequencies from...
Lee, Ki-Young; Nam, Sang Bum; Lee, Youn Woo; Han, Dong Woo; Cho, Nam Ryong; Lee, Jong Seok
Volatile anesthetics alter the arterial baroreflex (BRX) but its mechanisms are poorly understood. This study was designed to determine the effect of 1 and 2 minimal alveolar concentrations (MAC) of enflurane on the BRX parameters in unanesthetized brain stem-intact and decerebrate rats. Under enflurane anesthesia, the femoral artery and both femoral vein were catheterized for pressor (phenylephrine) and depressor (nitroprusside) drug delivery and continuous blood pressure measurements. Decerebration was performed at midcollicular level. BRX tests were performed in 3 time periods; before enflurane (conscious brain-intact), during 1 or 2 MAC enflurane exposure 1 hour after a sham operation or a decerebration operation, and 2 hours after the termination of enflurane (zero enflurane). Mean arterial pressure (MAP) and heart rate (HR) were fitted to a sigmoid logistic equation, the Boltzman equation. The curve of best fit was obtained with a computer program. 1 MAC and 2 MAC of enflurane shifted MAP-HR baroreflex curves to the left in the all groups and significantly attenuated the baroreflex range. The slope of conscious intact period and zero enflurane period of each group did not change significantly, but during the enflurane period the slope was significantly lowered. Enflurane depressed the baroreflex sensitivity (slope) and the HR range in a similar dose-dependent manner in both brain stem-intact and decerebrate rats. Such results draw into question whether the suprapontine sites contribute to enflurane's actions on cardiovascular autonomic regulation.
Yamazaki, F.; Sagawa, S.; Torii, R.; Endo, Y.; Shiraki, K.
The purpose of this study was to examine the effect of hyperthermia on the carotid baroreceptor-cardiac reflexes in humans. Nine healthy males underwent acute hyperthermia (esophageal temperature 38.0° C) produced by hot water-perfused suits. Beat-to-beat heart rate (HR) responses were determined during positive and negative R-wave-triggered neck pressure steps from +40 to -65 mm Hg during normothermia and hyperthermia. The carotid baroreceptor-cardiac reflex sensitivity was evaluated from the maximum slope of the HR response to changes in carotid distending pressure. Buffering capacity of the HR response to carotid distending pressure was evaluated in % from a reference point calculated as (HR at 0 mm Hg neck pressure-minimum HR)/HR range ×100. An upward shift of the curve was evident in hyperthermia because HR increased from 57.7+/-2.4 beats/min in normothermia to 88.7+/-4.1 beats/min in hyperthermia (Phypotension is reduced and the capacity for bradycardia response to sudden hypertension is increased during acute hyperthermia.
... result of taking a drug such as a beta blocker . A lower heart rate is also common for ... 100. Medication use: Meds that block your adrenaline (beta blockers) tend to slow your pulse, while too much ...
Ho, K. K.; Moody, G. B.; Peng, C. K.; Mietus, J. E.; Larson, M. G.; Levy, D.; Goldberger, A. L.
BACKGROUND: Despite much recent interest in quantification of heart rate variability (HRV), the prognostic value of conventional measures of HRV and of newer indices based on nonlinear dynamics is not universally accepted. METHODS AND RESULTS: We have designed algorithms for analyzing ambulatory ECG recordings and measuring HRV without human intervention, using robust methods for obtaining time-domain measures (mean and SD of heart rate), frequency-domain measures (power in the bands of 0.001 to 0.01 Hz [VLF], 0.01 to 0.15 Hz [LF], and 0.15 to 0.5 Hz [HF] and total spectral power [TP] over all three of these bands), and measures based on nonlinear dynamics (approximate entropy [ApEn], a measure of complexity, and detrended fluctuation analysis [DFA], a measure of long-term correlations). The study population consisted of chronic congestive heart failure (CHF) case patients and sex- and age-matched control subjects in the Framingham Heart Study. After exclusion of technically inadequate studies and those with atrial fibrillation, we used these algorithms to study HRV in 2-hour ambulatory ECG recordings of 69 participants (mean age, 71.7+/-8.1 years). By use of separate Cox proportional-hazards models, the conventional measures SD (P.3), were not. In multivariable models, DFA was of borderline predictive significance (P=.06) after adjustment for the diagnosis of CHF and SD. CONCLUSIONS: These results demonstrate that HRV analysis of ambulatory ECG recordings based on fully automated methods can have prognostic value in a population-based study and that nonlinear HRV indices may contribute prognostic value to complement traditional HRV measures.
Jones, Salene M W; Guthrie, Katherine A; Reed, Susan D; Landis, Carol A; Sternfeld, Barbara; LaCroix, Andrea Z; Dunn, Andrea; Burr, Robert L; Newton, Katherine M
Heart rate variability (HRV) reflects the integration of the parasympathetic nervous system with the rest of the body. Studies on the effects of yoga and exercise on HRV have been mixed but suggest that exercise increases HRV. We conducted a secondary analysis of the effect of yoga and exercise on HRV based on a randomized clinical trial of treatments for vasomotor symptoms in peri/post-menopausal women. Randomized clinical trial of behavioral interventions in women with vasomotor symptoms (n=335), 40-62 years old from three clinical study sites. 12-weeks of a yoga program, designed specifically for mid-life women, or a supervised aerobic exercise-training program with specific intensity and energy expenditure goals, compared to a usual activity group. Time and frequency domain HRV measured at baseline and at 12 weeks for 15min using Holter monitors. Women had a median of 7.6 vasomotor symptoms per 24h. Time and frequency domain HRV measures did not change significantly in either of the intervention groups compared to the change in the usual activity group. HRV results did not differ when the analyses were restricted to post-menopausal women. Although yoga and exercise have been shown to increase parasympathetic-mediated HRV in other populations, neither intervention increased HRV in middle-aged women with vasomotor symptoms. Mixed results in previous research may be due to sample differences. Yoga and exercise likely improve short-term health in middle-aged women through mechanisms other than HRV. Copyright © 2016 Elsevier Ltd. All rights reserved.
Ozdemir, Murat; Arslan, Uğur; Türkoğlu, Sedat; Balcioğlu, Serhat; Cengel, Atiye
Heart rate variability (HRV) and heart rate turbulence are known to be disturbed and associated with excess mortality in heart failure. The aim of this study was to investigate whether losartan, when added on top of beta-blocker and angiotensin-converting enzyme inhibitor (ACEI) therapy, could improve these indices in patients with systolic heart failure. Seventy-seven patients (mean age 60.4 +/- 8.0, 80.5% male) with ischemic cardiomyopathy (mean ejection fraction 34.5 +/- 4.4%) and New York Heart Association Class II-III heart failure symptoms, already receiving a beta-blocker and an ACEI, were randomly assigned to either open-label losartan (losartan group) or no additional drug (control group) in a 2:1 ratio and the patients were followed for 12 weeks. The HRV and heart rate turbulence indices were calculated from 24-hour Holter recordings both at the beginning and at the end of follow-up. The baseline clinical characteristics, HRV, and heart rate turbulence indices were similar in the 2 groups. At 12 weeks of follow-up, all HRV parameters except pNN50 increased (SDNN: 113.2 +/- 34.2 versus 127.8 +/- 24.1, P = .001; SDANN: 101.5 +/- 31.7 versus 115.2 +/- 22.0, P = .001; triangular index: 29.9 +/- 11.1 versus 34.2 +/- 7.9, P = .008; RMSSD: 29.1 +/- 20.2 versus 34.3 +/- 23.0, P = .009; NN50: 5015.3 +/- 5554.9 versus 6446.7 +/- 6101.1, P = .024; NN50: 5.65 +/- 6.41 versus 7.24 +/- 6.99, P = .089; SDNNi: 45.1 +/- 13.3 versus 50.3 +/- 14.5, P = .004), turbulence onset decreased (-0. 61 +/- 1.70 versus -1.24 +/- 1.31, P = .003) and turbulence slope increased (4.107 +/- 3.881 versus 5.940 +/- 4.281, P = .004) significantly in the losartan group as compared with controls. A 12-week-long losartan therapy significantly improved HRV and heart rate turbulence in patients with Class II-III heart failure and ischemic cardiomyopathy already on beta-blockers and ACEI.
Surmely, Jean-François; Mohacsi, Paul; Schmid, Jean-Paul; Carrel, Thierry; Delacretaz, Etienne
A 19-year-old woman presented with decreased exercise tolerance 3 years after orthotopic heart transplantation. Exercise capacity was severely reduced, with a maximal workload of 84 W, corresponding to 56% of the predicted value. After exclusion of other causes, insufficient heart rate response to exercise was considered as the major contributor to her decreased exercise tolerance. Correction of this problem with the implantation of an AAIR pacemaker dramatically improved her physical performance, allowing her to win 5 gold medals at the European Heart and Lung Transplant Games. This case report illustrates how pacemaker therapy can dramatically improve the symptoms and performance of patients with chronotropic incompetence.
Arias-Ortega, R; Gaitán-González, M J; Yáñez-Suarez, O
An LMS-based algorithm to monitor fetal and maternal heart rate in real time was implemented and evaluated on a development platform. Hardware has three modules: dsPIC30F digital signal controller, a low-noise analog front end and a storage stage. They were evaluated using on-chip debugging tools and a patient simulator. Algorithm performance was tested using simulation tools and real data. Other measures like process run-times and power consumption, were analyzed to evaluate the design feasibility. Dataset was conformed by 25 annotated records from different gestational age pregnant women. Sensitivity and accuracy were used as performance measures. In general, sensitivity was high for maternal (95.3%) and fetal (87.1%) detections. Results showed that the chosen architecture can run efficiently the algorithm processes, obtaining high detection rates under appropriate SNR conditions.
Tomczy, Rita; Paluch, Katarzyna; Gałuszka-Bednarczyk, Anna; Milewicz, Tomasz; Janeczko, Jarosław; Klocek, Marek
The aim of the study was to evaluate changes in blood pressure and heart rate in women undergoing controlled ovarian stimulation (COH) in preparation for assisted reproduction techniques. Material and method: The comparison of blood pressure and heart rate measurements obtained from 5 women (age 35.3 +/- 9.4 years) was performed. The data were collected during the 24-hour ambulatory blood pressure monitoring (ABPM) using Holcard sphygmomanometer CR-07 Aspel S.A. at the beginning and in the last day of short protocol of COH with the use of triptorelin (Decapeptyl 0.1 mg/day--Ferring GmbH) and the total supply of Gonalu F 225 U/day--Merck Serono) and Menotropiny 75j FSH + LH 75 U/day (Merional Imed/lBSA). During COH the increase in the serum estradiol level was detected (54.03 +/- 9.4 pg/ml at baseline vs. 1128.7 +/- 208.6 pg/ml after COH, p < 0.001). However, there were no differences in SBP and DBP values before stimulation and on the day of its completion. Only the decrease of mean arterial pressure measured by oscillometric method was observed during the study (95.1 +/- 25.3 mmHg vs. 87.6 +/- 27.8 mmHg, p<0.02). Mean arterial pressure measured by oscillometric method decreased in the daytime measurements (98 +/- 27.3 mmHg vs. 92.8 +/- 26.5 mmHg, p<0.05) as well as in the nighttime measurements (84.4 +/- 17.4 mmHg vs. 78.8 +/- 14, 4 mmHg, p <0.05). After COH, the higher heart rate (HR) was measured (in overall ABPM statistics: baseline HR 68.5 +/- 12.8/min vs. 73.6 +/- 13.7/ min after COH, p<0.002 and also in daytime statistics: baseline HR70.8 +/- 13.6 / min vs. 76.3 +/- 15.5 / min after COH, p<0.002). The increase in serum estradiol level caused by COH leads to increase in heart rate and reduction in mean arterial pressure measured by oscillometric method. However, short-term increase in serum estradiol during COH is not associated with significant changes in systolic and diastolic blood pressure in women preparing for the in vitro procedure.
Gehrmann, Josef; Meister, Michael; Maguire, Colin T; Martins, Donna C; Hammer, Peter E; Neer, Eva J; Berul, Charles I; Mende, Ulrike
.... To elucidate the physiological role of G for the regulation of heart rate and electrophysiological function in vivo, we created transgenic mice with a reduced amount of membrane-bound G protein...
Armelin, Vinicius Araújo; da Silva Braga, Victor Hugo; Abe, Augusto Shinya; Rantin, Francisco Tadeu; Florindo, Luiz Henrique
Orthostasis dramatically influences the hemodynamics of terrestrial vertebrates, especially large and elongated animals such as snakes. When these animals assume a vertical orientation, gravity tends to reduce venous return, cardiac filling, cardiac output and blood pressure to the anterior regions of the body. The hypotension triggers physiological responses, which generally include vasomotor adjustments and tachycardia to normalize blood pressure. While some studies have focused on understanding the regulation of these vasomotor adjustments in ectothermic vertebrates, little is known about regulation and the importance of heart rate in these animals during orthostasis. We acquired heart rate and carotid pulse pressure (P PC) in pythons in their horizontal position, and during 30 and 60° inclinations while the animals were either untreated (control) or upon muscarinic cholinoceptor blockade and a double autonomic blockade. Double autonomic blockade completely eradicated the orthostatic-tachycardia, and without this adjustment, the P PC reduction caused by the tilts became higher than that which was observed in untreated animals. On the other hand, post-inclinatory vasomotor adjustments appeared to be of negligible importance in counterbalancing the hemodynamic effects of gravity. Finally, calculations of cardiac autonomic tones at each position revealed that the orthostatic-tachycardia is almost completely elicited by a withdrawal of vagal drive.
DeWayne P Williams
Full Text Available The Model of Neurovisceral Integration suggests that vagally mediated heart rate variability (vmHRV represents a psychophysiological index of inhibitory control and thus, is associated with emotion regulation capacity. Over the past decade, growing empirical evidence supports this notion, showing that those with higher resting vmHRV can regulate and control negative emotions more adequately. However, to our knowledge, no study has previously examined how resting vmHRV may relate to everyday perceived difficulties in emotion regulation. The present study attempts to examine such relationship in 183 undergraduate students (98 female, 60 minority, mean Age = 19.34. Resting vmHRV was collected during a 5-minute resting baseline period, and everyday difficulties in emotion regulation were assessed using the Difficulties in Emotion Regulation Scale (DERS. Controlling for potential confounds (including both trait anxiety and rumination, results revealed a negative relationship between resting vmHRV and DERS such that lower resting vmHRV was associated with greater difficulties in emotional control, especially a lack of emotional clarity and impulse control, as indicated by the respective subscales of the DERS. These findings provide further evidence for the Neurovisceral Integration Model, suggesting that emotional control and autonomic regulation share neural networks within the brain. Moreover, the present study extends prior research by highlighting two distinct facets of emotion regulation (impulse control and emotional clarity that should be of particular interest when investigating the link between emotion regulation, resting vmHRV, and related health outcomes including morbidity and mortality.
Morelli, Andrea; Ertmer, Christian; Westphal, Martin; Rehberg, Sebastian; Kampmeier, Tim; Ligges, Sandra; Orecchioni, Alessandra; D'Egidio, Annalia; D'Ippoliti, Fiorella; Raffone, Cristina; Venditti, Mario; Guarracino, Fabio; Girardis, Massimo; Tritapepe, Luigi; Pietropaoli, Paolo; Mebazaa, Alexander; Singer, Mervyn
β-Blocker therapy may control heart rate and attenuate the deleterious effects of β-adrenergic receptor stimulation in septic shock. However, β-Blockers are not traditionally used for this condition and may worsen cardiovascular decompensation related through negative inotropic and hypotensive effects. To investigate the effect of the short-acting β-blocker esmolol in patients with severe septic shock. Open-label, randomized phase 2 study, conducted in a university hospital intensive care unit (ICU) between November 2010 and July 2012, involving patients in septic shock with a heart rate of 95/min or higher requiring high-dose norepinephrine to maintain a mean arterial pressure of 65 mm Hg or higher. We randomly assigned 77 patients to receive a continuous infusion of esmolol titrated to maintain heart rate between 80/min and 94/min for their ICU stay and 77 patients to standard treatment. Our primary outcome was a reduction in heart rate below the predefined threshold of 95/min and to maintain heart rate between 80/min and 94/min by esmolol treatment over a 96-hour period. Secondary outcomes included hemodynamic and organ function measures; norepinephrine dosages at 24, 48, 72, and 96 hours; and adverse events and mortality occurring within 28 days after randomization. Targeted heart rates were achieved in all patients in the esmolol group compared with those in the control group. The median AUC for heart rate during the first 96 hours was -28/min (IQR, -37 to -21) for the esmolol group vs -6/min (95% CI, -14 to 0) for the control group with a mean reduction of 18/min (P heart rates to achieve target levels, without increased adverse events. The observed improvement in mortality and other secondary clinical outcomes warrants further investigation. clinicaltrials.gov Identifier: NCT01231698.
Sun, Yihong; Yu, Jinming; Hu, Dayi
To observe the current status of β-blocker (BB) use and heart rate control in Chinese patients with stable coronary artery disease (SCAD) based on subgroup data of the prospective observational longitudinal registry of patients with stable coronary artery disease (CLARIFY). The CLARIFY study is an international prospective observational registry of outpatients with SCAD. From November 2009 to July 2010, patients with SCAD were enrolled, and demographic information, clinical indicators, medication and blood flow reconstruction were collected. Patients were divided in three mutually exclusive categories by baseline pulse palpation heart rate(HR)≤60 beats per minute (bpm)(n=397), 61-69 bpm(n=782), and ≥70 bpm(n=1 443). The patients were also divided into taking BB or not taking BB groups. The aim of present study is to describe and analyze the current status and factors related to the HR control and BB use in the Chinese subgroup of CLARIFY. A total of 2 622 patients were enrolled from 56 centers across China. The mean age was (63.6±10.3) years old with 75.6% (1 983) male patients, 55.0% (1 443) patients had HR≥70 bpm. Mean HR measure by electrocardiogram(ECG) was (69.4±10.2)bpm, 50.9% (1 334 cases) patients had myocardial infarction(MI) history. A total of 21.9%(575 cases) patients had anginal symptoms; coronary angiography was performed in 88.8%(2 327 cases) of the patients. 76.2%(1 997 cases) patients were treated with BB (any molecule and any dose), 2.7% (70 cases) with digoxin or derivatives, 3.9% (103 cases) with verapamil or diltiazem, and 1.8% (47 cases) with amiodarone or dronedarone and 0.1%(2 cases) received ivabradine. BB use was similar among 3 HR groups(P>0.05). The independent risk factors associated with HR≥70 bpm were diabetes(OR=1.31), current smoker(OR=1.57), chronic heart failure(CHF) with NYHA Ⅲ (OR=2.13) and increased diastolic blood pressure (OR=1.30). Conversely, high physical activity (OR=0.61), former smoker (OR=0.76) and history
Boisvert, Danielle; Wells, Jessica; Armstrong, Todd; Lewis, Richard H; Woeckener, Matthias; Nobles, Matt R
There is consistent evidence to suggest that individuals with low resting heart rate are more likely to engage in a variety of antisocial behaviors. The present study examines whether this finding can be extended to stalking perpetration. Drawing from fearlessness theory and stimulation-seeking theory, as well as conceptual work of Meloy and Fisher, we find that individuals with low resting heart rates had significantly greater odds of engaging in stalking behavior, net of controls for sex, age, race, self-control, parental affection, delinquent peers, attitudes/beliefs toward crime, and aggression. When disaggregated by sex, the heart rate-stalking relationship was found to be significant for males, but not for females. The implications of these findings are discussed from a biosocial perspective.
Van der Meijden, W.P.; Fronczek, Rolf; Reijntjes, Robert H A M; Corssmit, Eleonora P M; Biermasz, Nienke R; Lammers, Gert Jan; van Dijk, J Gert; Thijs, Roland D
Narcolepsy with hypocretin deficiency is known to alter cardiovascular control during sleep, but its aetiology is disputed. As cardiovascular control differs between sleep states, and narcolepsy affects sleep architecture, controlling for both duration and transitions of sleep states is necessary.
Variations of high frequency parameter of heart rate variability following osteopathic manipulative treatment in healthy subjects compared to control group and sham therapy: randomized controlled trial
Full Text Available Context: Heart Rate Variability (HRV indicates how heart rate changes in response to inner and external stimuli. HRV is linked to health status and it is an indirect marker of the autonomic nervous system (ANS function. Objective: To investigate the influence of osteopathic manipulative treatment (OMT on ANS activity through changes of High Frequency, a heart rate variability index indicating the parasympathetic activity, in healthy subjects, compared with sham therapy and control group.Methods: Sixty-six healthy subjects, both male and female, were included in the present 3-armed randomized placebo controlled within subject cross-over single blinded study. Participants were asymptomatic adults, both smokers and non-smokers and not on medications. At enrollment subjects were randomized in 3 groups: A, B, C. Standardized structural evaluation followed by a patient need-based osteopathic treatment was performed in the first session of group A and in the second session of group B. Standardized evaluation followed by a protocoled sham treatment was provided in the second session of group A and in the first session of group B. No intervention was performed in the two sessions of group C, acting as a time-control. The trial was registered on clinicaltrials.gov identifier: NCT01908920.Main Outcomes Measures: HRV was calculated from electrocardiography before, during and after the intervention, for a total amount time of 25 minutes.Results: OMT engendered a statistically significant increase of parasympathetic activity, as shown by High Frequency rate (p<0.001, and decrease of sympathetic activity, as revealed by Low Frequency rate (p<0.01; results also showed a reduction of Low Frequency/High Frequency ratio (p<0.001 and Detrended fluctuation scaling exponent (p<0.05. Conclusions: Findings suggested that OMT can influence ANS activity increasing parasympathetic function and decreasing sympathetic activity, compared to sham therapy and control group.
Porciello, F; Rishniw, M; Ljungvall, I; Ferasin, L; Haggstrom, J; Ohad, D G
Sleeping and resting respiratory rates (SRR and RRR, respectively) are commonly used to monitor dogs and cats with left-sided cardiac disease and to identify animals with left-sided congestive heart failure (L-CHF). Dogs and cats with subclinical heart disease have SRRmean values dogs and cats with CHF that is well controlled with medical therapy. In this study, SRR and RRR were measured by the owners of 51 dogs and 22 cats with stable, well-controlled CHF. Median canine SRRmean was 20 breaths/min (7-39 breaths/min); eight dogs were ≥25 breaths/min and one dog only was ≥30 breaths/min. Canine SRRmean was unrelated to pulmonary hypertension or diuretic dose. Median feline SRRmean was 20 breaths/min (13-31 breaths/min); four cats were ≥25 breaths/min and only one cat was ≥30 breaths/min. Feline SRRmean was unrelated to diuretic dose. SRR remained stable during collection in both species with little day-to-day variability. The median canine RRRmean was 24 breaths/min (12-44 breaths/min), 17 were ≥25 breaths/min, seven were ≥30 breaths/min, two were >40 breaths/min. Median feline RRRmean was 24 breaths/min (15-45 breaths/min); five cats had RRRmean ≥25 breaths/min; one had ≥30 breaths/min, and two had ≥40 breaths/min. These data suggest that most dogs and cats with CHF that is medically well-controlled and stable have SRRmean and RRRmean dogs and cats. Copyright © 2015 Elsevier Ltd. All rights reserved.
Full Text Available Abstract Background An earlier study showed that a week of yoga practice was useful in stress management after a natural calamity. Due to heavy rain and a rift on the banks of the Kosi river, in the state of Bihar in north India, there were floods with loss of life and property. A week of yoga practice was given to the survivors a month after the event and the effect was assessed. Methods Twenty-two volunteers (group average age ± S.D, 31.5 ± 7.5 years; all of them were males were randomly assigned to two groups, yoga and a non-yoga wait-list control group. The yoga group practiced yoga for an hour daily while the control group continued with their routine activities. Both groups' heart rate variability, breath rate, and four symptoms of emotional distress using visual analog scales, were assessed on the first and eighth day of the program. Results There was a significant decrease in sadness in the yoga group (p Conclusions A week of yoga can reduce feelings of sadness and possibly prevent an increase in anxiety in flood survivors a month after the calamity. Trial Registration Clinical Trials Registry of India: CTRI/2009/091/000285
We assessed adherence to European Society of Cardiology heart rate guidelines (i.e. heart rates less than 70bpm) in patients with chronic stable heart failure. We also investigated the percent of patients on target doses of rate controlling drugs.
DeBoer, Mark D; Cherñavvsky, Daniel R; Topchyan, Katarina; Kovatchev, Boris P; Francis, Gary L; Breton, Marc D
To evaluate the safety and performance of using a heart rate (HR) monitor to inform an artificial pancreas (AP) system during exercise among adolescents with type 1 diabetes (T1D). In a randomized, cross-over trial, adolescents with T1D age 13 - 18 years were enrolled to receive on separate days either the unmodified UVa AP (stdAP) or an AP system connected to a portable HR monitor (AP-HR) that triggered an exercise algorithm for blood glucose (BG) control. During admissions participants underwent a structured exercise regimen. Hypoglycemic events and CGM tracings were compared between the two admissions, during exercise and for the full 24-hour period. Eighteen participants completed the trial. While number of hypoglycemic events during exercise and rest was not different between visits (0.39 AP-HR vs 0.50 stdAP), time below 70 mg dL -1 was lower on AP-HR compared to stdAP, 0.5±2.1% vs 7.4±12.5% (P = 0.028). Time with BG within 70-180 mg dL -1 was higher for the AP-HR admission vs stdAP during the exercise portion and overall (96% vs 87%, and 77% vs 74%), but these did not reach statistical significance (P = 0.075 and P = 0.366). Heart rate signals can safely and efficaciously be integrated in a wireless AP system to inform of physical activity. While exercise contributes to hypoglycemia among adolescents, even when using an AP system, informing the system of exercise via a HR monitor improved time <70 mg dL -1 . Nonetheless, it did not significantly reduce the total number of hypoglycemic events, which were low in both groups. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Hagensen, Mette K; Abe, Augusto S; Wang, Tobias
in systemic blood pressure (Psys). At 30 °C the baroreflex was more pronounced at a blood pressure lower than control value (52.3 cmH2O) with a maximal baroreflex gain of 1.97 beats min-1 cmH2O- 1 at a Psys of 41.9 cmH2O, and therefore seems to counteract hypotension. In contrast, the maximal baroreflex at 15......It has been suggested that ectothermic vertebrates primarily control blood pressure to protect the pulmonary vasculature from oedema caused by high pressure, while endothermic vertebrates control blood pressure to maintain adequate oxygen delivery to the tissues. In the present study we have...... °C was found at a Psys almost equal to the control value. The highest baroreflex gain in response to change in blood pressure was measured at the highest temperature. Thus, C. latirostris exhibit a temperature dependent barostatic response....
Luman, M.; Oosterlaan, J.; Hyde, C.; van Meel, C.S.; Sergeant, J.A.
Background: Both theoretical and clinical accounts of attention-deficit/ hyperactivity disorder (ADHD) implicate a dysfunctional reinforcement system. This study investigated heart rate parameters in response to feedback associated with reward and response cost in ADHD children and controls aged 8
Hyunbin Kwon; Heenam Yoon; Dawoon Jung; Sangho Choi; Jaewon Choi; Yujin Lee; Do-Un Jeong; Kwangsuk Park
The objectives of this study are to investigate heart rate variability (HRV) in major depressive disorder patients (MDD) and healthy controls during different sleep stages, and to examine the association of HRV during sleep and depression severity. Polysomnography was recorded from 15 depressive patients with a higher beck depression inventory index (BDI > 25, H-BDI-D), 15 depressive patients with a lower BDI index (BDI ≤ 25, L-BDI-D) and 15 healthy controls. HRV was calculated during the first three rapid eye movements (REM) periods and non-REM stages (i.e. sleep stage 2 and 3) with time domain, power spectral and fractal analysis. As a result, H-BDI-D patients showed the highest short-term fractal alpha-1 exponent during first REM period and healthy controls had the lowest values. Our results suggest an association between the depression severity and the autonomic nerve function, especially during the first REM sleep. The pathophysiological analysis for this property should be conducted in future prospective studies.
Andrewartha, Sarah J; Tazawa, Hiroshi; Burggren, Warren W
Long-term measurements (days and weeks) of heart rate (HR) have elucidated infradian rhythms in chicken embryos and circadian rhythms in chicken hatchlings. However, such rhythms are lacking in emu embryos and only rarely observed in emu hatchlings. Parasympathetic control of HR (instantaneous heart rate (IHR) decelerations) occurs at ∼60% of incubation in both precocial and altricial avian embryos, with sympathetic control (IHR accelerations) becoming more prevalent close to hatching. A large increase in avian embryonic HR occurs during hatching (presumably an energetically expensive process, i.e. increased oxygen consumption M(O) ₂), beginning during pipping when a physical barrier to O(2) conductance is removed. Alterations in ambient O(2) have little effect on early embryonic HR, likely due to the low rate of M(O)₂ of early embryos and the fact that adequate O(2) delivery can occur via diffusion. As M(O)₂ increases in advanced embryos and circulatory convection becomes important for O(2) delivery, alterations in ambient O(2) have more profound effects on embryonic HR. Early embryos demonstrate a wide ambient temperature (T(a)) tolerance range compared with older embryos. In response to a rapid decrease in T(a), embryonic HR decreases (stroke volume and blood flow are preserved) in an exponential fashion to a steady state (from which it can potentially recover if re-warmed). A more severe decrease in T(a) results in complete cessation of HR; however, depending on developmental age, embryos are able to survive severe cold exposure and cessation of HR for up to 24h in some instances. The development of endothermy can be tracked by measuring baseline HR during T(a) changes. HR patterns change from thermo-conformity to thermoregulation (reverse to T(a) changes). Further, IHR low frequency oscillations mediated by the autonomic nervous system are augmented at low T(a)s in hatchlings. Transitions of baseline HR during endothermic development are unique to
Full Text Available INTRODUCTION: It is well known that type 2 diabetes mellitus (T2DM produces cardiovascular autonomic neuropathy (CAN, which may affect the cardiac autonomic modulation. However, it is unclear whether the lack of glycemic control in T2DM without CAN could impact negatively on cardiac autonomic modulation. Objective: To evaluate the relationship between glycemic control and cardiac autonomic modulation in individuals with T2DM without CAN. Descriptive, prospective and cross sectional study.METHODS: Forty-nine patients with T2DM (51±7 years were divided into two groups according to glycosylated hemoglobin (HbA1c: G1≤7% and G2>7.0%. Resting heart rate (HR and RR interval (RRi were obtained and calculated by linear (Mean iRR; Mean HR; rMSSD; STD RR; LF; HF; LF/HF, TINN and RR Tri, and non-linear (SD1; SD2; DFα1; DFα2, Shannon entropy; ApEn; SampEn and CD methods of heart rate variability (HRV. Insulin, HOMA-IR, fasting glucose and HbA1c were obtained by blood tests.RESULTS: G2 (HbA1c≤7% showed lower values for the mean of iRR; STD RR; RR Tri, TINN, SD2, CD and higher mean HR when compared with G1 (HbA1c > 7%. Additionally, HbA1c correlated negatively with mean RRi (r=0.28, p=0.044; STD RR (r=0.33, p=0.017; RR Tri (r=-0.35, p=0.013, SD2 (r=-0.39, p=0.004 and positively with mean HR (r=0.28, p=0.045. Finally, fasting glucose correlated negatively with STD RR (r=-0.36, p=0.010; RR Tri (r=-0.36, p=0.010; TINN (r=-0.33, p=0.019 and SD2 (r=-0.42, p=0.002.CONCLUSION: We concluded that poor glycemic control is related to cardiac autonomic modulation indices in individuals with T2DM even if they do not present cardiovascular autonomic neuropathy.
Lin, Shu-Ling; Huang, Ching-Ya; Shiu, Shau-Ping; Yeh, Shu-Hui
Mental health professionals experiencing work-related stress may experience burn out, leading to a negative impact on their organization and patients. The aim of this study was to examine the effects of yoga classes on work-related stress, stress adaptation, and autonomic nerve activity among mental health professionals. A randomized controlled trial was used, which compared the outcomes between the experimental (e.g., yoga program) and the control groups (e.g., no yoga exercise) for 12 weeks. Work-related stress and stress adaptation were assessed before and after the program. Heart rate variability (HRV) was measured at baseline, midpoint through the weekly yoga classes (6 weeks), and postintervention (after 12 weeks of yoga classes). The results showed that the mental health professionals in the yoga group experienced a significant reduction in work-related stress (t = -6.225, p yoga and control groups, we found the yoga group significantly decreased work-related stress (t = -3.216, p = .002), but there was no significant change in stress adaptation (p = .084). While controlling for the pretest scores of work-related stress, participants in yoga, but not the control group, revealed a significant increase in autonomic nerve activity at midpoint (6 weeks) test (t = -2.799, p = .007), and at posttest (12 weeks; t = -2.099, p = .040). Because mental health professionals experienced a reduction in work-related stress and an increase in autonomic nerve activity in a weekly yoga program for 12 weeks, clinicians, administrators, and educators should offer yoga classes as a strategy to help health professionals reduce their work-related stress and balance autonomic nerve activities. © 2015 The Authors. Worldviews on Evidence-Based Nursing published by Wiley Periodicals, Inc. on behalf of Society for Worldviews on Evidence-Based Nursing.
Muehlsteff, J.; Christian Meyer; Drexel, T.
ABSTRACT Background: Heart failure (HF) and atrial fibrillation (AF), emerging as two epidemics of the 21st century, are commonly associated with each other. Both have been mechanistically linked to changes in cardiac vagal control. The importance of peripheral chemosensors, residing in the carotid
Dyrda, Katia; Roy, Denis; Leduc, Hugues; Talajic, Mario; Stevenson, Lynne Warner; Guerra, Peter G; Andrade, Jason; Dubuc, Marc; Macle, Laurent; Thibault, Bernard; Rivard, Lena; Khairy, Paul
Rate and rhythm control strategies for atrial fibrillation (AF) are not always effective or well tolerated in patients with congestive heart failure (CHF). We assessed reasons for treatment failure, associated characteristics, and effects on survival. A total of 1,376 patients enrolled in the AF-CHF trial were followed for 37 ± 19 months, 206 (15.0%) of whom failed initial therapy leading to crossover. Rhythm control was abandoned more frequently than rate control (21.0% vs. 9.1%, P CHF. The most common reasons for treatment failure are inefficacy for rhythm control and worsening heart failure for rate control. Changing strategies does not impact survival. © 2015 Wiley Periodicals, Inc.
Brito Díaz, Buenaventura; Alemán Sánchez, José Juan; Cabrera de León, Antonio
Heart rate reflects autonomic nervous system activity. Numerous studies have demonstrated that an increased heart rate at rest is associated with cardiovascular morbidity and mortality as an independent risk factor. It has been shown a link between cardiac autonomic balance and inflammation. Thus, an elevated heart rate produces a micro-inflammatory response and is involved in the pathogenesis of endothelial dysfunction. In turn, decrease in heart rate produces benefits in congestive heart failure, myocardial infarction, atrial fibrillation, obesity, hyperinsulinemia, insulin resistance, and atherosclerosis. Alteration of other heart rate-related parameters, such as their variability and recovery after exercise, is associated with risk of cardiovascular events. Drugs reducing the heart rate (beta-blockers, calcium antagonists and inhibitors of If channels) have the potential to reduce cardiovascular events. Although not recommended in healthy subjects, interventions for reducing heart rate constitute a reasonable therapeutic goal in certain pathologies. Copyright © 2013 Elsevier España, S.L. All rights reserved.
Full Text Available Abstract Background Very few studies have analysed heart rate (HR with regard to music playing, and the scarce evidence available is controversial. The purpose of this study was to analyse the HR response of professional musicians during their real-work activity. Methods Sixty-two voluntary professional musicians (20 women, 42 men, whose ages ranged between 15 and 71 years old, underwent the test while playing their instruments in real life scenarios, i.e. rehearsals, practice and public concerts. The musicians carried Sport Tester PE4000 (Polar®, Finland pulsometers to record their HR. In order to compare data from differently aged subjects we calculated their Maximum Theoretical Heart Rate (MTHR. Later on we found out the MTHR percentages (%MTHR corresponding to the registered HR of each subject in different situations. The value of the MTHR for every musician was obtained by means of the 220 – age (in years formula. Results Throughout the HR recordings, we have observed that musicians present a heightened HR while playing (in soloists, mean and maximum HR were 72% and 85%MTHR, respectively. Cardiac demand is significantly higher in concerts than in rehearsals while performing the same musical piece. The HR curves corresponding to the same musician playing in repeated concerts (with the same programme were similar. Conclusion The cardiac demand of a professional instrument player is higher than previously described, much greater than what would be expected from a supposedly sedentary activity.
Iñesta, Claudia; Terrados, Nicolás; García, Daniel; Pérez, José A
Very few studies have analysed heart rate (HR) with regard to music playing, and the scarce evidence available is controversial. The purpose of this study was to analyse the HR response of professional musicians during their real-work activity. Sixty-two voluntary professional musicians (20 women, 42 men), whose ages ranged between 15 and 71 years old, underwent the test while playing their instruments in real life scenarios, i.e. rehearsals, practice and public concerts. The musicians carried Sport Tester PE4000 (Polar(R), Finland) pulsometers to record their HR.In order to compare data from differently aged subjects we calculated their Maximum Theoretical Heart Rate (MTHR). Later on we found out the MTHR percentages (%MTHR) corresponding to the registered HR of each subject in different situations. The value of the MTHR for every musician was obtained by means of the 220 - age (in years) formula. Throughout the HR recordings, we have observed that musicians present a heightened HR while playing (in soloists, mean and maximum HR were 72% and 85%MTHR, respectively). Cardiac demand is significantly higher in concerts than in rehearsals while performing the same musical piece. The HR curves corresponding to the same musician playing in repeated concerts (with the same programme) were similar. The cardiac demand of a professional instrument player is higher than previously described, much greater than what would be expected from a supposedly sedentary activity.
Background Chronic work-related stress is an independent risk factor for cardiometabolic diseases and associated mortality, particularly when compounded by a sedentary work environment. The purpose of this study was to determine if an office worksite-based hatha yoga program could improve physiological stress, evaluated via heart rate variability (HRV), and associated health-related outcomes in a cohort of office workers. Methods Thirty-seven adults employed in university-based office positions were randomized upon the completion of baseline testing to an experimental or control group. The experimental group completed a 10-week yoga program prescribed three sessions per week during lunch hour (50 min per session). An experienced instructor led the sessions, which emphasized asanas (postures) and vinyasa (exercises). The primary outcome was the high frequency (HF) power component of HRV. Secondary outcomes included additional HRV parameters, musculoskeletal fitness (i.e. push-up, side-bridge, and sit & reach tests) and psychological indices (i.e. state and trait anxiety, quality of life and job satisfaction). Results All measures of HRV failed to change in the experimental group versus the control group, except that the experimental group significantly increased LF:HF (p = 0.04) and reduced pNN50 (p = 0.04) versus control, contrary to our hypotheses. Flexibility, evaluated via sit & reach test increased in the experimental group versus the control group (p yoga sessions (n = 11) to control (n = 19) yielded the same findings, except that the high adherers also reduced state anxiety (p = 0.02) and RMSSD (p = 0.05), and tended to improve the push-up test (p = 0.07) versus control. Conclusions A 10-week hatha yoga intervention delivered at the office worksite during lunch hour did not improve HF power or other HRV parameters. However, improvements in flexibility, state anxiety and musculoskeletal fitness were noted with high adherence
Madalena D. Costa
Full Text Available Background: We recently introduced the concept of heart rate fragmentation along with a set of metrics for its quantification. The term was coined to refer to an increase in the percentage of changes in heart rate acceleration sign, a dynamical marker of a type of anomalous variability. The effort was motivated by the observation that fragmentation, which is consistent with the breakdown of the neuroautonomic-electrophysiologic control system of the sino-atrial node, could confound traditional short-term analysis of heart rate variability.Objective: The objectives of this study were to: (1 introduce a symbolic dynamical approach to the problem of quantifying heart rate fragmentation; (2 evaluate how the distribution of the different dynamical patterns (“words” varied with the participants' age in a group of healthy subjects and patients with coronary artery disease (CAD; and (3 quantify the differences in the fragmentation patterns between the two sample populations.Methods: The symbolic dynamical method employed here was based on a ternary map of the increment NN interval time series and on the analysis of the relative frequency of symbolic sequences (words with a pre-defined set of features. We analyzed annotated, open-access Holter databases of healthy subjects and patients with CAD, provided by the University of Rochester Telemetric and Holter ECG Warehouse (THEW.Results: The degree of fragmentation was significantly higher in older individuals than in their younger counterparts. However, the fragmentation patterns were different in the two sample populations. In healthy subjects, older age was significantly associated with a higher percentage of transitions from acceleration/deceleration to zero acceleration and vice versa (termed “soft” inflection points. In patients with CAD, older age was also significantly associated with higher percentages of frank reversals in heart rate acceleration (transitions from acceleration to
Costa, Madalena D; Davis, Roger B; Goldberger, Ary L
Background: We recently introduced the concept of heart rate fragmentation along with a set of metrics for its quantification. The term was coined to refer to an increase in the percentage of changes in heart rate acceleration sign, a dynamical marker of a type of anomalous variability. The effort was motivated by the observation that fragmentation, which is consistent with the breakdown of the neuroautonomic-electrophysiologic control system of the sino-atrial node, could confound traditional short-term analysis of heart rate variability. Objective: The objectives of this study were to: (1) introduce a symbolic dynamical approach to the problem of quantifying heart rate fragmentation; (2) evaluate how the distribution of the different dynamical patterns ("words") varied with the participants' age in a group of healthy subjects and patients with coronary artery disease (CAD); and (3) quantify the differences in the fragmentation patterns between the two sample populations. Methods: The symbolic dynamical method employed here was based on a ternary map of the increment NN interval time series and on the analysis of the relative frequency of symbolic sequences (words) with a pre-defined set of features. We analyzed annotated, open-access Holter databases of healthy subjects and patients with CAD, provided by the University of Rochester Telemetric and Holter ECG Warehouse (THEW). Results: The degree of fragmentation was significantly higher in older individuals than in their younger counterparts. However, the fragmentation patterns were different in the two sample populations. In healthy subjects, older age was significantly associated with a higher percentage of transitions from acceleration/deceleration to zero acceleration and vice versa (termed "soft" inflection points). In patients with CAD, older age was also significantly associated with higher percentages of frank reversals in heart rate acceleration (transitions from acceleration to deceleration and vice
Full Text Available Abstract Background Chronic work-related stress is a significant and independent risk factor for cardiovascular and metabolic diseases and associated mortality, particularly when compounded by a sedentary work environment. Heart rate variability (HRV provides an estimate of parasympathetic and sympathetic autonomic control, and can serve as a marker of physiological stress. Hatha yoga is a physically demanding practice that can help to reduce stress; however, time constraints incurred by work and family life may limit participation. The purpose of the present study is to determine if a 10-week, worksite-based yoga program delivered during lunch hour can improve resting HRV and related physical and psychological parameters in sedentary office workers. Methods and design This is a parallel-arm RCT that will compare the outcomes of participants assigned to the experimental treatment group (yoga to those assigned to a no-treatment control group. Participants randomized to the experimental condition will engage in a 10-week yoga program delivered at their place of work. The yoga sessions will be group-based, prescribed three times per week during lunch hour, and will be led by an experienced yoga instructor. The program will involve teaching beginner students safely and progressively over 10 weeks a yoga sequence that incorporates asanas (poses and postures, vinyasa (exercises, pranayama (breathing control and meditation. The primary outcome of this study is the high frequency (HF spectral power component of HRV (measured in absolute units; i.e. ms2, a measure of parasympathetic autonomic control. Secondary outcomes include additional frequency and time domains of HRV, and measures of physical functioning and psychological health status. Measures will be collected prior to and following the intervention period, and at 6 months follow-up to determine the effect of intervention withdrawal. Discussion This study will determine the effect of worksite
Vest, Adriana N; Li, Qiao; Liu, Chengyu; Nemati, Shamim; Shah, Amit; Clifford, Gari D
Heart rate variability (HRV) metrics hold promise as potential indicators for autonomic function, prediction of adverse cardiovascular outcomes, psychophysiological status, and general wellness. Although the investigation of HRV has been prevalent for several decades, the methods used for preprocessing, windowing, and choosing appropriate parameters lack consensus among academic and clinical investigators. A comprehensive and open-source modular program is presented for calculating HRV implemented in Matlab with evidence-based algorithms and output formats. We compare our software with another widely used HRV toolbox written in C and available through PhysioNet.org. Our findings show substantially similar results when using high quality electrocardiograms (ECG) free from arrhythmias. Our software shows equivalent performance alongside an established predecessor and includes validated tools for performing preprocessing, signal quality, and arrhythmia detection to help provide standardization and repeatability in the field, leading to fewer errors in the presence of noise or arrhythmias. Copyright © 2017 Elsevier Inc. All rights reserved.
Variations of high frequency parameter of heart rate variability following osteopathic manipulative treatment in healthy subjects compared to control group and sham therapy: randomized controlled trial.
Ruffini, Nuria; D'Alessandro, Giandomenico; Mariani, Nicolò; Pollastrelli, Alberto; Cardinali, Lucia; Cerritelli, Francesco
Heart Rate Variability (HRV) indicates how heart rate changes in response to inner and external stimuli. HRV is linked to health status and it is an indirect marker of the autonomic nervous system (ANS) function. To investigate the influence of osteopathic manipulative treatment (OMT) on cardiac autonomic modulation in healthy subjects, compared with sham therapy and control group. Sixty-six healthy subjects, both male and female, were included in the present 3-armed randomized placebo controlled within subject cross-over single blinded study. Participants were asymptomatic adults (26.7 ± 8.4 y, 51% male, BMI 18.5 ± 4.8), both smokers and non-smokers and not on medications. At enrollment subjects were randomized in three groups: A, B, C. Standardized structural evaluation followed by a patient need-based osteopathic treatment was performed in the first session of group A and in the second session of group B. Standardized evaluation followed by a protocoled sham treatment was provided in the second session of group A and in the first session of group B. No intervention was performed in the two sessions of group C, acting as a time-control. The trial was registered on clinicaltrials.gov identifier: NCT01908920. HRV was calculated from electrocardiography before, during and after the intervention, for a total amount time of 25 min and considering frequency domain as well as linear and non-linear methods as outcome measures. OMT engendered a statistically significant increase of parasympathetic activity, as shown by High Frequency power (p ANS activity increasing parasympathetic function and decreasing sympathetic activity, compared to sham therapy and control group.
Qiu, Shuang; Shi, Shaobo; Ping, Haiqin; Zhou, Sanfeng; Wang, Hui; Yang, Bo
To quantify the efficacy of pretreatment with ivabradine compared to β-blockers before computed tomography coronary angiography (CTCA) via a meta-analysis of clinical randomized controlled trial data. We conducted a search for randomized controlled trials of pretreatment with ivabradine compared to β-blockers before CTCA in Medline, PubMed, Embase, SCI/SSCI/A&HCI, SAS Publishers, Web of Science, and the Cochrane Central Register. The Jadad quality score of the included studies, and the mean difference (MD) in heart rate reduction, were indicators of efficacy. RevMan 5.2 and Stata 12.0 software were used for the meta-analysis. Eight studies involving a total of 1,324 patients were included in the final analysis. The results showed that ivabradine was significantly more effective at improving the heart rate of patients achieving the target heart rate (<65 bpm) during CTCA (OR 5.02; 95% CI 3.16-7.98, p < 0.00001, I2 = 20%). A comparison of efficacy between ivabradine and β-blockers showed a statistically significant effect of ivabradine on heart rate reduction during CTCA (MD -4.39; 95% CI -4.80 to -3.99, p < 0.00001, I2 = 0%). Ivabradine also led to a significant reduction in heart rate prior to CTCA (MD -5.33; 95% CI -10.26 to -0.39, p = 0.03, I2 = 92%). In terms of the total reduction in heart rate during CTCA, significant differences were noted between the ivabradine group and the β-blocker group (MD 2.64; 95% CI 1.25-4.02, p = 0.0002, I2 = 0%). The mean percentage reduction in heart rate in the ivabradine group was significantly higher than that in the β-blocker group (MD 7.18; 95% CI 5.64-8.72, p < 0.00001, I2 = 43%). Ivabradine had no significant effect on either systolic blood pressure (BP) (MD 11.41; 95% CI 6.43-16.40, p < 0.00001, I2 = 85%) or diastolic BP (MD 1.79; 95% CI -0.00 to 3.58, p = 0.05, I2 = 56%). Compared to β-blockers for heart rate reduction, ivabradine is a potentially attractive alternative for patients undergoing CTCA. © 2016 S
Ramos Batalha, Priscila; Borghi-Silva, Audrey; Campos Freire, Renato; Zanela DA Silva Arêas, Fernando; Peixoto Tinoco Arêas, Guilherme
Elastic bands are therapeutic tools widely used in rehabilitation. However, knowledge regarding autonomic cardiovascular overload during this type of resistance exercise is limited. This study assessed the autonomic control of heart rate during an incremental exercise protocol with elastic bands in sedentary healthy young individuals. Ten young women were subjected to an exercise protocol involving bilateral shoulder flexion to 90° with various thicknesses of elastic bands; the exercise was performed for 36 uninterrupted repetitions with a 15-minute rest interval between sets. During the exercise, the RR intervals (R-Ri) were collected and determined, the heart rate variability was analyzed. All subjects completed the exercise protocol. Heart rate increased, and RR intervals decreased from the yellow elastic band onward. However, the square root of the sum of the square of the difference of RR intervals divided by the number of RR interval, standard deviation of the arithmetic mean of all normal RR intervals, and standard deviation of the RR interval instantaneous intervals of type I decreased significantly when performed with the green band onward (Pheart rate. However, the green elastic band induces less total and parasympathetic modulation heart rate variability.
Coumel, P; Maison-Blanche, P; Catuli, D
The relationships between heart rate (HR) and HR variability (HRV) are not simple. Because both depend on the autonomic nervous system (ANS), they are not independent variables. Technically, the quantification of HRV is influenced by the duration of the cardiac cycles. The complexity of these relationships does not justify ignoring HR when studying HRV, as frequently occurs. Using spectral and nonspectral methods, the HR and various normalized and non-normalized indices of HRV were studied in 24-hour recordings of a homogeneous cohort of seventeen 20-year-old healthy males. The HR-HRV relationships were appraised by analyzing the same data in two different ways. The 24 mean hourly values provide consistent information on the circadian behavior of the indices, while the average 24-hour individual data show a wide spectrum of normality. Combined approaches allow assessment of the direct impact of RR interval on HRV evaluation. The correlations between HR and normalized indices of HRV are weaker in 24-hour individual data than in pooled hourly data of the same individuals. These correlations are close to 1 in the latter case, which does not mean that measuring HRV is simply another method of evaluating HR, but that normal physiology supposes a harmonious behavior of the various indices. When considered individually without normalization, the specific indices of vagal modulation (high-frequency band of the spectrum, short-term HR oscillations of the nonspectral analysis) consistently increase at night and diminish during the day. However, the low-frequency power, which supposedly reflects sympathetic influences, also increases at night, whereas more logically the longer HR oscillations would predominate during the day. Moreover, the selective analysis of HR oscillations during HR acceleration or decrease indicates that their behavior differs accordingly. We recommend that closer attention be paid to the complex relationships between HR and HRV. The strong correlations
Bartur, Gadi; Vatine, Jean-Jacques; Raphaely-Beer, Noa; Peleg, Sara; Katz-Leurer, Michal
The objective of this study is to assess the autonomic nerve heart rate regulation system at rest and its immediate response to paced breathing among patients with complex regional pain syndrome (CRPS) as compared with age-matched healthy controls. Quasiexperimental. Outpatient clinic. Ten patients with CRPS and 10 age- and sex-matched controls. Participants underwent Holter ECG (NorthEast Monitoring, Inc., Maynard, MA, USA) recording during rest and biofeedback-paced breathing session. Heart rate variability (HRV), time, and frequency measures were assessed. HRV and time domain values were significantly lower at rest among patients with CRPS as compared with controls. A significant association was noted between pain rank and HRV frequency measures at rest and during paced breathing; although both groups reduced breathing rate significantly during paced breathing, HRV time domain parameters increased only among the control group. The increased heart rate and decreased HRV at rest in patients with CRPS suggest a general autonomic imbalance. The inability of the patients to increase HRV time domain values during paced breathing may suggest that these patients have sustained stress response with minimal changeability in response to slow-paced breathing stimuli. Wiley Periodicals, Inc.
Ogliari, Giulia; Mahinrad, Simin; Stott, David J
BACKGROUND: Heart rate and heart rate variability, markers of cardiac autonomic function, have been linked with cardiovascular disease. We investigated whether heart rate and heart rate variability are associated with functional status in older adults, independent of cardiovascular disease. METHODS......: We obtained data from the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER). A total of 5042 participants were included in the present study, and mean followup was 3.2 years. Heart rate and heart rate variability were derived from baseline 10-second electrocardiograms. Heart rate.......3 years. At baseline, higher heart rate was associated with worse ADL and IADL, and lower SDNN was related to worse IADL (all p values heart rate (range 71-117 beats/min) had a 1.79-fold (95% confidence interval [CI] 1.45-2.22) and 1.35-fold (95% CI 1...
Gebben, V. D.; Webb, J. A., Jr.
Inexpensive industrial pneumatic components are combined to produce control system to drive sac-type heart-assistance blood pump with controlled pulsatile pressure that makes pump rate of flow sensitive to venous /atrial/ pressure, while stroke is centered about set operating point and pump is synchronized with natural heart.
Bogucki, Sz; Noszczyk-Nowak, A
Heart rate variability is an established risk factor for mortality in both healthy dogs and animals with heart failure. The aim of this study was to compare short-term heart rate variability (ST-HRV) parameters from 60-min electrocardiograms in dogs with sick sinus syndrome (SSS, n=20) or chronic mitral valve disease (CMVD, n=20) and healthy controls (n=50), and to verify the clinical application of ST-HRV analysis. The study groups differed significantly in terms of both time - and frequency- domain ST-HRV parameters. In the case of dogs with SSS and healthy controls, particularly evident differences pertained to HRV parameters linked directly to the variability of R-R intervals. Lower values of standard deviation of all R-R intervals (SDNN), standard deviation of the averaged R-R intervals for all 5-min segments (SDANN), mean of the standard deviations of all R-R intervals for all 5-min segments (SDNNI) and percentage of successive R-R intervals >50 ms (pNN50) corresponded to a decrease in parasympathetic regulation of heart rate in dogs with CMVD. These findings imply that ST-HRV may be useful for the identification of dogs with SSS and for detection of dysautonomia in animals with CMVD.
Krnjajic, Davor; Allen, Dustin R; Butts, Cory L; Keller, David M
Whole body heat stress (WBH) results in numerous cardiovascular alterations that ultimately reduce orthostatic tolerance. While impaired carotid baroreflex (CBR) function during WBH has been reported as a potential reason for this decrement, study design considerations may limit interpretation of previous findings. We sought to test the hypothesis that CBR function is unaltered during WBH. CBR function was assessed in 10 healthy male subjects (age: 26 ± 3; height: 185 ± 7 cm; weight: 82 ± 10 kg; BMI: 24 ± 3 kg/m(2); means ± SD) using 5-s trials of neck pressure (+45, +30, and +15 Torr) and neck suction (-20, -40, -60, and -80 Torr) during normothermia (NT) and passive WBH (Δ core temp ∼1°C). Analyses of stimulus response curves (four-parameter logistic model) for CBR control of heart rate (CBR-HR) and mean arterial pressure (CBR-MAP), as well as separate two-way ANOVA of the hypotensive and hypertensive stimuli (factor 1: thermal condition, factor 2: chamber pressure), were performed. For CBR-HR, maximal gain was increased during WBH (-0.73 ± 0.11) compared with NT (-0.39 ± 0.04, mean ± SE, P = 0.03). In addition, the CBR-HR responding range was increased during WBH (33 ± 5) compared with NT (19 ± 2 bpm, P = 0.03). Separate analysis of hypertensive stimulation revealed enhanced HR responses during WBH at -40, -60, and -80 Torr (condition × chamber pressure interaction, P = 0.049) compared with NT. For CBR-MAP, both logistic analysis and separate two-way ANOVA revealed no differences during WBH. Therefore, in response to passive WBH, CBR control of heart rate (enhanced) and arterial pressure (no change) is well preserved. Copyright © 2016 the American Physiological Society.
V. A. Sydorenko
Full Text Available The choice of parameters of functional status of organism of pregnant, possibility and value of dynamic diagnostics of weight of preeklampsiya, is in-process examined, on the base of study of indexes of variability rhythm of heart of mother, allowing to get the current estimation of the state of the vegetative nervous system (VNS of organism of pregnant, calculation of dosages of medicines and control of efficiency of the conducted therapy by means of algorithms of fuzzy logic. Formalization of set of entrance variables for managers
Gent, Sabine; Kleinbongard, Petra; Dammann, Philip; Neuhäuser, Markus; Heusch, Gerd
Heart rate correlates inversely with life span across all species, including humans. In patients with cardiovascular disease, higher heart rate is associated with increased mortality, and such patients benefit from pharmacological heart rate reduction. However, cause-and-effect relationships between heart rate and longevity, notably in healthy individuals, are not established. We therefore prospectively studied the effects of a life-long pharmacological heart rate reduction on longevity in mice. We hypothesized, that the total number of cardiac cycles is constant, and that a 15% heart rate reduction might translate into a 15% increase in life span. C57BL6/J mice received either placebo or ivabradine at a dose of 50 mg/kg/day in drinking water from 12 weeks to death. Heart rate and body weight were monitored. Autopsy was performed on all non-autolytic cadavers, and parenchymal organs were evaluated macroscopically. Ivabradine reduced heart rate by 14% (median, interquartile range 12-15%) throughout life, and median life span was increased by 6.2% (p = 0.01). Body weight and macroscopic findings were not different between placebo and ivabradine. Life span was not increased to the same extent as heart rate was reduced, but nevertheless significantly prolonged by 6.2%.
Hnatkova, Katerina; Johannesen, Lars; Vicente, Jose; Malik, Marek
Little experience exists with the heart rate correction of J-Tpeak and Tpeak-Tend intervals. In a population of 176 female and 176 male healthy subjects aged 32.3±9.8 and 33.1±8.4years, respectively, curve-linear and linear relationship to heart rate was investigated for different sections of the JT interval defined by the proportions of the area under the vector magnitude of the reconstructed 3D vectorcardiographic loop. The duration of the JT sub-section between approximately just before the T peak and almost the T end was found heart rate independent. Most of the JT heart rate dependency relates to the beginning of the interval. The duration of the terminal T wave tail is only weakly heart rate dependent. The Tpeak-Tend is only minimally heart rate dependent and in studies not showing substantial heart rate changes does not need to be heart rate corrected. For any correction formula that has linear additive properties, heart rate correction of JT and JTpeak intervals is practically the same as of the QT interval. However, this does not apply to the formulas in the form of Int/RR(a) since they do not have linear additive properties. Copyright © 2017 Elsevier Inc. All rights reserved.
Downs, Thomas; Zlomke, Evelyn
Context: Numerous randomized controlled trials have demonstrated limited efficacy of intrapartum fetal heart rate monitoring in improving fetal outcome. A potential reason is the wide variability in clinical decision making seen with its use. Standardizing management of variant intrapartum fetal heart rate tracings may reduce this variability and lead to improvement in fetal outcome.
Variations of high frequency parameter of heart rate variability following osteopathic manipulative treatment in healthy subjects compared to control group and sham therapy: randomized controlled trial
Ruffini, Nuria; D'Alessandro, Giandomenico; Mariani, Nicolò; Pollastrelli, Alberto; Cardinali, Lucia; Cerritelli, Francesco
Context: Heart Rate Variability (HRV) indicates how heart rate changes in response to inner and external stimuli. HRV is linked to health status and it is an indirect marker of the autonomic nervous system (ANS) function. Objective: To investigate the influence of osteopathic manipulative treatment (OMT) on cardiac autonomic modulation in healthy subjects, compared with sham therapy and control group. Methods: Sixty-six healthy subjects, both male and female, were included in the present 3-armed randomized placebo controlled within subject cross-over single blinded study. Participants were asymptomatic adults (26.7 ± 8.4 y, 51% male, BMI 18.5 ± 4.8), both smokers and non-smokers and not on medications. At enrollment subjects were randomized in three groups: A, B, C. Standardized structural evaluation followed by a patient need-based osteopathic treatment was performed in the first session of group A and in the second session of group B. Standardized evaluation followed by a protocoled sham treatment was provided in the second session of group A and in the first session of group B. No intervention was performed in the two sessions of group C, acting as a time-control. The trial was registered on clinicaltrials.gov identifier: NCT01908920. Main Outcomes Measures: HRV was calculated from electrocardiography before, during and after the intervention, for a total amount time of 25 min and considering frequency domain as well as linear and non-linear methods as outcome measures. Results: OMT engendered a statistically significant increase of parasympathetic activity, as shown by High Frequency power (p < 0.001), expressed in normalized and absolute unit, and possibly decrease of sympathetic activity, as revealed by Low Frequency power (p < 0.01); results also showed a reduction of Low Frequency/High Frequency ratio (p < 0.001) and Detrended fluctuation scaling exponent (p < 0.05). Conclusions: Findings suggested that OMT can influence ANS activity increasing
Blitz, P.S.; Hoogstraten, J.; Mulder, G.
"Several investigators have shown that diminished sinus arrhythmia can be seen as an indication of increased mental load. The present experiment deals with the influence of different levels of mental load, operationalized as the number of binary choices per minute, on the regularity of the heart
Barachi, M. (Mitra)
The problem addressed in this report is to verify the possibility of using an optical sensor in the SaxShirt in order to extract the heart rate. There are specifically three questions that we try to address. 1) How is it possible to extract heart rate (BPM) from the optical sensor? 2) Is it
Henrard, Valérie; Ducharme, Anique; Khairy, Paul; Gisbert, Alejandro; Roy, Denis; Levesque, Sylvie; Talajic, Mario; Thibault, Bernard; Racine, Normand; White, Michel; Guerra, Peter G; Tardif, Jean-Claude
In patients with heart failure and atrial fibrillation, the AF-CHF (Atrial Fibrillation and Congestive Heart Failure) trial did not demonstrate the superiority of rhythm control (RhyC) over a rate control (RaC) strategy on cardiovascular mortality. Nevertheless, deleterious hemodynamic effects of atrial fibrillation can lead to further decrease in left ventricular (LV) function and progression of symptoms. This echocardiographic sub-study was designed to compare the effects of the two treatment strategies on LV ejection fraction (LVEF), chamber volumes and dimensions, valvular regurgitation and functional status. A total of 59 patients (29 RhyC, 30 RaC) aged 67±8 years (14% women), enrolled in the AF-CHF trial at the Montreal Heart Institute underwent standardized echocardiograms at baseline and at 12 months. Mean LVEF at baseline was severely depressed (RhyC: 27.0±4.9% and RaC: 27.6±7.4%, p=0.73), and improved to a similar degree in both groups (RhyC: +8.0±10.4% and RaC: +4.5±10.6, both p<0.05; p=0.19 for RhyC versus RaC). Other echocardiographic parameters, such as LV end-systolic volume index and degree of mitral and tricuspid regurgitation, remained unchanged. New York Heart Association functional class and distance walked in 6 min improved significantly in both groups (RhyC: +48.9±78.7 m and RaC: +47.2±96.7 m, both p≤0.01), with no difference between RhyC and RaC strategies. Improvements in LVEF and functional status are observed after 12 months in patients with heart failure and atrial fibrillation, regardless of whether rate or rhythm control strategies are used. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Serafin, Stefania; Erkut, Cumhur
This paper investigates whether generative music, adapted to a user's heart beat rate, can be used to ease the perceived exertion. A generative system was implemented and tested on 13 test participants in a controlled environment on a training bike. The test participants performed a cycling workout...... of three minutes in two conditions in a self-chosen pace, with and without music. Their pulse were used as the physiological exertion. The perceived exertion was rated by the test participants according to Borg’s 6-20 exertion scale. Five out of 13 participants showed indications supporting the notion......, while 2 out of 13 indicated the opposite. 6 out of 13 participants neither showed indications supporting nor opposing the theory. The results could be useful for exercises, where the change of heart pulse is gradual, but further work is needed in cadance-based exercises....
Chehuen, Marcel; Cucato, Gabriel G; Carvalho, Celso Ricardo F; Ritti-Dias, Raphael M; Wolosker, Nelson; Leicht, Anthony S; Forjaz, Cláudia Lúcia M
This study investigated the effects of walking training (WT) on cardiovascular function and autonomic regulation in patents with intermittent claudication (IC). Randomized controlled trial. Forty-two male patients with IC (≥50years) were randomly allocated into two groups: control (CG, n=20, 30min of stretching exercises) and WT (WTG, n=22, 15 bouts of 2min of walking interpolated by 2min of upright rest-walking intensity was set at the heart rate of pain threshold). Both interventions were performed twice/week for 12 weeks. Walking capacity (maximal treadmill test), blood pressure (auscultatory), cardiac output (CO 2 rebreathing), heart rate (ECG), stroke volume, systemic vascular resistance, forearm and calf vascular resistance (plethysmography), and low (LF) and high frequency (HF) components of heart rate variability and spontaneous baroreflex sensitivity were measured at baseline and after 12 weeks of the study. WT increased total walking distance (+302±85m, p=0.001) and spontaneous baroreflex sensitivity (+2.13±1.07ms/mmHg, p=0.02). Additionally, at rest, WT decreased systolic and mean blood pressures (-10±3 and -5±2mmHg, p=0.001 and p=0.01, respectively), cardiac output (-0.37±0.24l/min, p=0.03), heart rate (-4±2bpm, p=0.001), forearm vascular resistance (-8.5±2.8U, p=0.02) and LF/HF (-1.24±0.99, p=0.001). No change was observed in the CG. In addition to increasing walking capacity, WT improved cardiovascular function and autonomic regulation in patients with IC. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Patients with angina pectoris or myocardial infarction frequently present without evidence of cardiac-specific heart enzymes by laboratory analysis or specific pathologic electro-cardiogram findings. The current study analyzed the efficacy of the erythrocyte sedimentation rate as an additional potential indicator for coronary heart disease, the aim being to enable quicker identification of patients with angina pectoris or myocardial infarction so that they can be more rapidly treated. Patients with angina pectoris or myocardial infarction who had undergone a heart catheter examination were included in the study. The diagnosis of acute coronary heart disease was made by the physician who performed coronary angiography. Patients without coronary heart disease were used as a control group. The erythrocyte sedimentation rate was measured in all patients. Patients with angina pectoris or myocardial infarction and an inflammatory or tumor disease were excluded. The erythrocyte sedimentation rate was prolonged in 79 (58.09%) of 136 patients; 69 (50.74%) patients (95% confidence interval ±8.4%, 42.34%-59.14%) had coronary heart disease and a prolonged erythrocyte sedimentation rate. The erythrocyte sedimentation rate was prolonged in ten (7.35%) patients (95% confidence interval ±4.39%, 2.96%-11.74%) without coronary heart disease by coronary angiography. The specificity of the erythrocyte sedimentation rate for coronary heart disease was 70.59% and the sensitivity was 67.65%. Erythrocyte sedimentation rate may be a useful additional diagnostic criterion for coronary heart disease.
Kapu, Hemanth; Saraswat, Kavisha; Ozturk, Yusuf; Cetin, A. Enis
In this paper, we describe a non-invasive and non-contact system of estimating resting heart rate (RHR) using a pyroelectric infrared (PIR) sensor. This infrared system monitors and records the chest motion of a subject using the analog output signal of the PIR sensor. The analog output signal represents the composite motion due to inhale-exhale process with magnitude much larger than the minute vibrations of heartbeat. Since the acceleration of the heart activity is much faster than breathing the second derivative of the PIR sensor signal monitoring the chest of the subject is used to estimate the resting heart rate. Experimental results indicate that this ambient sensor can measure resting heart rate with a chi-square significance level of α = 0.05 compared to an industry standard PPG sensor. This new system provides a low cost and an effective way to estimate the resting heart rate, which is an important biological marker.
Jakub Sławomir Gąsior
Full Text Available Background: Since heart rate variability (HRV is associated with average heart rate (HR and respiratory rate (RespRate, alterations in these parameters may impose changes in HRV. Hence the repeatability of HRV measurements may be affected by differences in HR and RespRate. The study aimed to evaluate HRV repeatability and its association with changes in HR and RespRate.Methods: Forty healthy volunteers underwent two ECG examinations seven days apart. Standard HRV indices were calculated from 5-min ECG recordings. The ECG-derived respiration signal was estimated to assess RespRate. To investigate HR impact on HRV, HRV parameters were corrected for prevailing HR. Results: Differences in HRV parameters between the measurements were associated with the changes in HR and RespRate. However, in multiple regression analysis only HR alteration proved to be independent determinant of the HRV differences – every change in HR by 1 bpm changed HRV values by 16.5% on average. After overall removal of HR impact on HRV, coefficients of variation of the HRV parameters significantly dropped on average by 26.8% (p < 0.001, i.e. by the same extent HRV reproducibility improved. Additionally, the HRV correction for HR decreased association between RespRate and HRV. Conclusions: In stable conditions, HR but not RespRate is the most powerful factor determining HRV reproducibility and even a minimal change of HR may considerably alter HRV. However, the removal of HR impact may significantly improve HRV repeatability. The association between HRV and RespRate seems to be, at least in part, HR dependent.
Voropay Sergej Nikolaevich
Full Text Available It is shown the efficiency of the use of «Sigma Sport 1300» in operational control of special endurance athletes. The study involved 10 athletes of higher discharges. At baseline for each athlete was defined range of indicators of heart rate and intensity of the zone. It is established that the best indicators of changes in special endurance observed in the control of the intensity of objective internal performance. It is noted that the subjective assessment can be influenced by many extraneous factors: the cumulative effect of exercise, emotional athlete to the start of classes.
Rigsby, Cynthia K.; Nicholas, Angela C. [Children' s Memorial Hospital, Department of Medical Imaging, 2300 Children' s Plaza, Box 9, Chicago, IL (United States); deFreitas, R.A. [Children' s Memorial Hospital, Department of Pediatrics, Chicago, IL (United States); Leidecker, Christianne [Siemens Medical Solutions, Malvern, PA (United States); Johanek, Andrew J. [Children' s Memorial Hospital, Department of Medical Imaging, 2300 Children' s Plaza, Box 9, Chicago, IL (United States); Provena St. Joseph Medical Center, Department of Radiology, Joliet, IL (United States); Anley, Peter [Children' s Memorial Hospital, Pharmacy Department, Chicago (United States); Wang, Deli [Children' s Memorial Hospital, Biostatistical Research Department, Chicago, IL (United States); Uejima, Tetsu [Children' s Memorial Hospital, Department of Anesthesiology, Chicago, IL (United States)
The adult practice for ECG-gated single-source 64-slice coronary CTA (CCTA) includes administering beta-blockers to reduce heart rate. There are limited data on this process in children. To evaluate the safety and efficacy of a drug regimen to decrease heart rate before performing CCTA in children. IV remifentanil and esmolol infusion were chosen to decrease heart rate in 41 children (mean age 6.5 years) while they were under general anesthesia (GA) for CCTA. Drug doses, changes in heart rate and procedural complications were recorded. CCTA image quality was graded on a scale of 1 to 5. The relationships between image quality and heart rate and image quality and age were evaluated. Patient effective radiation doses were calculated. Heart rates were lowered utilizing esmolol (4 children), remifentanil (2 children) or both (35 children); 26 children received nitroglycerin for coronary vasodilation. The mean decrease in heart rate was 26%. There were no major complications. The average image-quality score was 4.4. Higher heart rates were associated with worse image quality (r = 0.67, P < 0.0001). Older age was associated with better image quality (r = 0.66, P < 0.0001). Effective radiation doses were 0.7 to 7.0 mSv. Heart rate reduction for pediatric CCTA can be safely and effectively achieved while yielding high-quality images. (orig.)
Lundby, C; Van Hall, Gerrit
We have measured maximal heart rate during a graded maximal bicycle exercise test to exhaustion in five healthy climbers before and during an expedition to Mt. Everest. Maximal heart rates at sea level were 186 (177-204) beats/min(-1) at sea level and 170 (169-182) beats/min(-1) with acute hypoxia....... After 1, 4 and 6 weeks of acclimatization to 5400 m, maximal heart rates were 155 (135-182), 158 (144-182), and 155 (140-183) beats/min(-1), respectively. Heart rates of two of the climbers were measured during their attempt to reach the summit of Mt. Everest without the use of supplemental oxygen....... The peak heart rates at 8,750 m for the two climbers were 142 and 144 beats/min(-1), which were similar to their maximal heart rates during exhaustive bicycle exercise at 5,400 m, the values being 144 and 148 beats/min(-1), respectively. The peak heart rates at 8,750 m are in agreement with other field...
Cagirci, Goksel; Cay, Serkan; Karakurt, Ozlem
BACKGROUND: Cigarette smoking increases the risk of cardiovascular events related with several mechanisms. The most suggested mechanism is increased activity of sympathetic nervous system. Heart rate variability (HRV) and heart rate turbulence (HRT) has been shown to be independent and powerful...... predictors of mortality in a specific group of cardiac patients. The goal of this study was to assess the effect of heavy cigarette smoking on cardiac autonomic function using HRV and HRT analyses. METHODS: Heavy cigarette smoking was defined as more than 20 cigarettes smoked per day. Heavy cigarette smokers......, 69 subjects and nonsmokers 74 subjects (control group) were enrolled in this study. HRV and HRT analyses [turbulence onset (TO) and turbulence slope (TS)] were assessed from 24-hour Holter recordings. RESULTS: The values of TO were significantly higher in heavy cigarette smokers than control group...
Panigrahy, D; Rakshit, M; Sahu, P K
This paper describes a field programmable gate array (FPGA) implementation of a system that calculates the heart rate from Electrocardiogram (ECG) signal. After heart rate calculation, tachycardia, bradycardia or normal heart rate can easily be detected. ECG is a diagnosis tool routinely used to access the electrical activities and muscular function of the heart. Heart rate is calculated by detecting the R peaks from the ECG signal. To provide a portable and the continuous heart rate monitoring system for patients using ECG, needs a dedicated hardware. FPGA provides easy testability, allows faster implementation and verification option for implementing a new design. We have proposed a five-stage based methodology by using basic VHDL blocks like addition, multiplication and data conversion (real to the fixed point and vice-versa). Our proposed heart rate calculation (R-peak detection) method has been validated, using 48 first channel ECG records of the MIT-BIH arrhythmia database. It shows an accuracy of 99.84%, the sensitivity of 99.94% and the positive predictive value of 99.89%. Our proposed method outperforms other well-known methods in case of pathological ECG signals and successfully implemented in FPGA.
Lundby, C; Møller, P; Kanstrup, I L
This study examined the effects of dopamine D(2)-receptor blockade on the early decrease in maximal heart rate at high altitude (4559 m). We also attempted to clarify the time-dependent component of this reduction and the extent to which it is reversed by oxygen breathing. Twelve subjects performed...... progressively decreased the maximal heart rate from day 1 and onwards; also, hypoxia by itself increased plasma noradrenaline levels after maximal exercise. Domperidone further increased maximal noradrenaline concentrations, but had no effect on maximal heart rate. On each study day at altitude, oxygen...... breathing completely reversed the decrease in maximal heart rate to values not different from those at sea level. In conclusion, dopamine D(2)-receptor blockade with domperidone demonstrates that hypoxic exercise in humans activates D(2)-receptors, resulting in a decrease in circulating levels...
Full Text Available ABSTRACT: Regular physical activity can cause some long term effects on human body. The purpose of this research was to examine the effect of sport rock climbing (SRC training at 70 % HRmax level on echocardiography (ECHO and heart rate variability (HRV for one hour a day and three days a week in an eight-week period. A total of 19 adults participated in this study voluntarily. The subjects were randomly divided into two groups as experimental (EG and control (CG. While the EG went and did climbing training by using the top-rope method for 60 minutes a day, three days a week for 8 weeks and didn’t join any other physical activity programs, CG didn’t train and take part in any physical activity during the course of the study. Same measurements were repeated at the end of eight weeks. According to the findings, no significant change was observed in any of the ECHO and HRV parameters. However, an improvement was seen in some HRV parameters [average heart rate (HRave, standard deviation of all NN intervals (SDNN, standard deviation of the averages of NN intervals in all five-minute segments of the entire recording (SDANN, percent of difference between adjacent NN intervals that are greater than 50 ms (PNN50, square root of the mean of the sum of the squares of differences between adjacent NN interval (RMSSD] in EG. An exercise program based on SRC should be made more than eight weeks in order to have statistically significant changes with the purpose of observing an improvement in heart structure and functions. Keywords: Echocardiography, heart rate variability, sport rock climbing
Yin, De-Chun; Wang, Zhao-Jun; Guo, Shuai; Xie, Hong-Yu; Sun, Lin; Feng, Wei; Qiu, Wei; Qu, Xiu-Fen
Background This study is aimed to evaluate the clinical significance of heart rate turbulence (HRT) parameters in predicting the prognosis in patients with chronic heart failure (CHF). Methods From June 2011 to December 2012, a total of 104 CHF patients and 30 healthy controls were enrolled in this study. We obtained a 24-hour Holter ECG recording to assess the HRT parameters, included turbulence onset (TO), turbulence slope (TS), standard deviation of N-N intervals (SDNN), and resting heart ...
Solanki, Jayesh Dalpatbhai; Basida, Sanket D; Mehta, Hemant B; Panjwani, Sunil J; Gadhavi, Bhakti P; Patel, Pathik
Type 2 diabetes mellitus (T2DM) is a proven threat of cardiac dysautonomia with paucity of studies from India. Poor disease control makes it further worse with co-existence of hypertension in majority. Heart rate variability (HRV) is a validated noninvasive tool to assess cardiac autonomic status. We studied HRV parameters of type 2 diabetics looking for effects of disease control and other co-existing risk factors. Ninety-eight hypertensive and forty normotensive under-treatment, Gujarati type 2 diabetics were evaluated for disease control and risk stratification. Five minutes resting, HRV was measured by Variowin HR, software-based instrument, using standard protocols to record time domain, frequency domain, and Poincare plot HRV parameters. They were compared between subgroups for the difference with P < 0.05 defining statistical significance. All HRV parameters were reduced in type 2 diabetics, having mean age 56 years, mean duration 6 years with poor glycemic but comparatively better pressure control. HRV parameters were significantly not different in good compared to poor glycemics or in subjects with optimum pressure control than those without it. Results did not differ significantly, by the presence of individual cardiovascular risk factor in diabetics except resting heart rate. Our findings of HRV suggest that type 2 diabetics with poor glycemic control do not have a significant difference of cardiac dysautonomia by pressure control, glycemic control, and absence of risk cardiovascular factor. It suggests diabetes as a major cause for cardiac dysautonomia, residual risk despite treatment and need for HRV screening, strict glycemic control, and further studies.
Jayesh Dalpatbhai Solanki
Full Text Available Background: Type 2 diabetes mellitus (T2DM is a proven threat of cardiac dysautonomia with paucity of studies from India. Poor disease control makes it further worse with co-existence of hypertension in majority. Heart rate variability (HRV is a validated noninvasive tool to assess cardiac autonomic status. Aim: We studied HRV parameters of type 2 diabetics looking for effects of disease control and other co-existing risk factors. Materials and Methods: Ninety-eight hypertensive and forty normotensive under–treatment, Gujarati type 2 diabetics were evaluated for disease control and risk stratification. Five minutes resting, HRV was measured by Variowin HR, software-based instrument, using standard protocols to record time domain, frequency domain, and Poincare plot HRV parameters. They were compared between subgroups for the difference with P< 0.05 defining statistical significance. Results: All HRV parameters were reduced in type 2 diabetics, having mean age 56 years, mean duration 6 years with poor glycemic but comparatively better pressure control. HRV parameters were significantly not different in good compared to poor glycemics or in subjects with optimum pressure control than those without it. Results did not differ significantly, by the presence of individual cardiovascular risk factor in diabetics except resting heart rate. Conclusion: Our findings of HRV suggest that type 2 diabetics with poor glycemic control do not have a significant difference of cardiac dysautonomia by pressure control, glycemic control, and absence of risk cardiovascular factor. It suggests diabetes as a major cause for cardiac dysautonomia, residual risk despite treatment and need for HRV screening, strict glycemic control, and further studies.
Al Bannay, Rashed; Böhm, Michael; Husain, Aysha
To study the clinical significance of presenting blood pressure parameters and heart rate in patients with hypertensive crisis. In patients admitted with hypertensive crisis between January 2011 and May 2011, demography, mode of presentation, co-morbidities, blood pressure readings, and heart rate at presentation were documented. Further clustering of hypertensive crisis into emergency or urgency was based on the presence or absence of target organ involvement. The relationship between blood pressure parameters, heart rate, and other variables was analyzed. 189 patients in sinus rhythm were enrolled in this pilot study. The rate of hypertensive urgency was 56 %, whereas the rate of hypertensive emergency was 44 %, respectively. Subjects with hypertensive emergency had a higher mean heart rate (93 ± 22.7 bpm) than those with urgency (81 ± 11.5 bpm) (P = 0.015). Women had higher heart rates (92 ± 18.5 bpm) than men (86 ± 17.6 bpm) (P = 0.014). Heart rates below 100 bpm had a specificity of 94 %, classifying patients as hypertensive urgency. Tachycardia had a powerful statistical association with hypertensive left ventricular failure (P pulse pressure, and mean blood pressure relates neither to urgency nor to emergency. Diabetic patients with HBA1c levels of more than 53 mmol/mol had a heart rate of more than 100 bpm (P = 0.015) during hypertensive crisis. Normal heart rate is characteristic of hypertensive urgency. Tachycardia in this setting is an ominous sign and denotes hypertensive complications in particular left ventricular failure. Among diabetics, elevated heart rate is associated with poor glycemic control.
Laumbach, Robert J; Kipen, Howard M; Ko, Susan; Kelly-McNeil, Kathie; Cepeda, Clarimel; Pettit, Ashley; Ohman-Strickland, Pamela; Zhang, Lin; Zhang, Junfeng; Gong, Jicheng; Veleeparambil, Manoj; Gow, Andrew J
For many individuals, daily commuting activities on roadways account for a substantial proportion of total exposure, as well as peak-level exposures, to traffic-related air pollutants (TRAPS) including ultrafine particles, but the health impacts of these exposures are not well-understood. We sought to determine if exposure to TRAPs particles during commuting causes acute oxidative stress in the respiratory tract or changes in heart rate variability (HRV), a measure of autonomic activity. We conducted a randomized, cross-over trial in which twenty-one young adults took two 1.5-hr rides in a passenger vehicle in morning rush-hour traffic. The subjects wore a powered-air-purifying respirator, and were blinded to high-efficiency particulate air (HEPA) filtration during one of the rides. At time points before and after the rides, we measured HRV and markers of oxidative stress in exhaled breath condensate (EBC) including nitrite, the sum of nitrite and nitrate, malondialdehyde, and 8-isoprostane. We used mixed linear models to evaluate the effect of exposure on EBC and HRV outcomes, adjusting for pre-exposure response levels. We used linear models to examine the effects of particle concentrations on EBC outcomes at post-exposure time points. Mean EBC nitrite and the sum of nitrite and nitrate were increased from baseline at immediately post-exposure comparing unfiltered to filtered rides (2.11 μM vs 1.70 μM, p = 0.02 and 19.1 μM vs 10.0 μM, p = 0.02, respectively). Mean EBC malondialdehyde (MDA) concentrations were about 10% greater following the unfiltered vs. filtered exposures, although this result was not statistically significant. We found no significant associations between exposure to traffic particles and HRV outcomes at any of the time points. At immediately post-exposure, an interquartile range increase in particle number concentration was associated with statistically significant increases in nitrite (99.4%, 95% CI 32.1% to 166.7%) and
Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth
HEART RATE AND HEART RATE VARIABILITY IN DOGS WITH DIFFERENT DEGREES OF MYXOMATOUS MITRAL VALVE DISEASE. CE Rasmussen1, T Falk1, NE Zois1, SG Moesgaard1, HD Pedersen2, J Häggström3 and LH Olsen1. 1. Department of Basic Animal and Veterinary Sciences, Faculty of Life Sciences, University of Copenh......HEART RATE AND HEART RATE VARIABILITY IN DOGS WITH DIFFERENT DEGREES OF MYXOMATOUS MITRAL VALVE DISEASE. CE Rasmussen1, T Falk1, NE Zois1, SG Moesgaard1, HD Pedersen2, J Häggström3 and LH Olsen1. 1. Department of Basic Animal and Veterinary Sciences, Faculty of Life Sciences, University...
Full Text Available Objective: To study the change of heart rate deceleration capacity ( DC and heart rate variability in patients with chronic heart failure (CHF and its relationship with left ventricular ejection fraction (LVEF. Methods: DC, LVEF, time and frequency domain parameters of HRV were measured in 66 patients with CHF and 34 healthy adults (control group by using 24h Holter recordings and Echocardiography. The standard deviation of normal R-R intervals( SDNN, squares of differences between adjacent NN intervals ( RMSSD，low frequency power( LFn and high frequency power( HFn and the changes of LVEF were compared between the two groups，the relationship between DC，LVEF and HRV were studied in patients with CHF. Results: The median value of DC in the patients with CHF was significantly lower than that in control group( 3.1 ± 2.4 ms vs 7.2 ± 1.3 ms，P <0.01．Incidence of abnormal DC in the CHF group was 57.5%，which was significantly higher than that in the control group (P <0.01．The HRV index, including SDNN、RMSSD、LFn、HFn, in the CHF group was significantly lower than that in normal control group (P < 0.01. Significant positive correlation between HRV index and LVEF were confirmed (P < 0.01. Conclusions: DC and HRV index are lower in patients with CHF and have a good correlation with the left ventricular ejection fraction.
Nussinovitch, Naomi; Livneh, Avi; Katz, Keren; Langevitz, Pnina; Feld, Olga; Nussinovitch, Moshe; Volovitz, Benjamin; Lidar, Merav; Nussinovitch, Udi
Familial Mediterranean fever (FMF) is a hereditary disease, characterized by recurrent episodes of fever and polyserositis. Heart rate variability (HRV) is a powerful, simple and reliable technique to evaluate autonomic nervous system function. Previous studies of physiologic parameters during tilt-test have suggested that patients with FMF have abnormal cardiovascular reactivity and occult dysautonomia. Prompted by these findings, the present study sought to evaluate HRV in patients with FMF, at rest and in the standing position. The study sample included 34 patients with FMF and 34 sex- and age-matched control subjects. All underwent electrocardiography according to strict criteria. HRV parameters were computed with custom-made software. There was no significant difference in HRV parameters, in either the supine or standing position, between the FMF and control groups. In both groups, the upright position was associated with a significant decrease, when compared with the supine position, in maximal RR interval, minimal RR, average RR, root square of successive differences in RR interval, number of intervals differing by >50 ms from preceding interval (NN50), NN50 divided by total number of intervals (pNN50) and high-frequency components as well as a significant increase in average heart rate, very low frequency or low-frequency components, low-frequency/high-frequency components ratio and total power. In conclusion, patients with FMF who are continuously treated with low-dose colchicine have not developed amyloidosis and have normal HRV parameters in the supine and upright position. Further investigation of occult dysautonomia in FMF is needed.
Sibilitz, K L; Berg, S K; Thygesen, Lau Caspar
age (hazard ratio (95% CI): 1.3 (1.0-1.6)), male sex (1.2 (1.0-1.5)), mitral valve surgery (1.3 (1.0-1.6)), and infective endocarditis after surgery (1.8 (1.1-3.0), p: 0.01) predicted readmission, whereas higher age (2.3 (1.0-5.4)), higher comorbidity score (3.2 (1.8-6.0)), and infective endocarditis......BACKGROUND: After heart valve surgery, knowledge on long-term self-reported health status and readmission is lacking. Thus, the optimal strategy for out-patient management after surgery remains unclear. METHODS: Using a nationwide survey with linkage to Danish registers with one year follow-up, we...... included all adults 6-12 months after heart valve surgery irrespective of valve procedure, during Jan-June 2011 (n = 867). Participants completed a questionnaire regarding health-status (n = 742), and answers were compared with age- and sex-matched healthy controls. Readmission rates and mortality were...
Boudet, G; Chamoux, A
We test the accuracy of two third generation heart rate monitors (HRM), Accurex Plus and Vantage NV and compare these data with those of an older monitor, PE 4000. Then we investigate responses of the HRM's to abnormal heart rhythms (HR). Accurex Plus and Vantage NV, and PE 4000 were tested in the laboratory under both stable and transient conditions. The Phantom 320 HR simulator gave 7 stable heart rates, each lasting 3 min. The responses of the HRM's to abnormal heart rhythms were tested with an automatic arrhythmia program lasting 17 min. The new HRM's, Accurex Plus and Vantage NV, were more accurate (89 to 94% and over 98% at +/-3 beats per min) in the stable state than the PE 4000. They all showed a smoothing effect in transient measurements, which was stronger in decelerating HR (1st case) than in accelerating HR (2nd case). - 1st case: Accurex Plus =Vantage NV >PE 4000 -2nd case: PE 4000 >Accurex =Vantage. Most isolated heart rhythm disorders (missing beat, pause 4 s, important bradycardia or tachycardia.
Weippert, Matthias; Behrens, Kristin; Rieger, Annika; Stoll, Regina; Kreuzfeld, Steffi
Aim was to elucidate autonomic responses to dynamic and static (isometric) exercise of the lower limbs eliciting the same moderate heart rate (HR) response. 23 males performed two kinds of voluntary exercise in a supine position at similar heart rates: static exercise (SE) of the lower limbs (static leg press) and dynamic exercise (DE) of the lower limbs (cycling). Subjective effort, systolic (SBP) and diastolic blood pressure (DBP), mean arterial pressure (MAP), rate pressure product (RPP) and the time between consecutive heart beats (RR-intervals) were measured. Time-domain (SDNN, RMSSD), frequency-domain (power in the low and high frequency band (LFP, HFP)) and geometric measures (SD1, SD2) as well as non-linear measures of regularity (approximate entropy (ApEn), sample entropy (SampEn) and correlation dimension D2) were calculated. Although HR was similar during both exercise conditions (88±10 bpm), subjective effort, SBP, DBP, MAP and RPP were significantly enhanced during SE. HRV indicators representing overall variability (SDNN, SD 2) and vagal modulated variability (RMSSD, HFP, SD 1) were increased. LFP, thought to be modulated by both autonomic branches, tended to be higher during SE. ApEn and SampEn were decreased whereas D2 was enhanced during SE. It can be concluded that autonomic control processes during SE and DE were qualitatively different despite similar heart rate levels. The differences were reflected by blood pressure and HRV indices. HRV-measures indicated a stronger vagal cardiac activity during SE, while blood pressure response indicated a stronger sympathetic efferent activity to the vessels. The elevated vagal cardiac activity during SE might be a response mechanism, compensating a possible co-activation of sympathetic cardiac efferents, as HR and LF/HF was similar and LFP tended to be higher. However, this conclusion must be drawn cautiously as there is no HRV-marker reflecting "pure" sympathetic cardiac activity.
Sharma, Vivek Kumar; Subramanian, Senthil Kumar; Radhakrishnan, Krishnakumar; Rajendran, Rajathi; Ravindran, Balasubramanian Sulur; Arunachalam, Vinayathan
Physical inactivity contributes to many health issues. The WHO-recommended physical activity for adolescents encompasses aerobic, resistance, and bone strengthening exercises aimed at achieving health-related physical fitness. Heart rate variability (HRV) and maximal aerobic capacity (VO2max) are considered as noninvasive measures of cardiovascular health. The objective of this study is to compare the effect of structured and unstructured physical training on maximal aerobic capacity and HRV among adolescents. We designed a single blinded, parallel, randomized active-controlled trial (Registration No. CTRI/2013/08/003897) to compare the physiological effects of 6 months of globally recommended structured physical activity (SPA), with that of unstructured physical activity (USPA) in healthy school-going adolescents. We recruited 439 healthy student volunteers (boys: 250, girls: 189) in the age group of 12-17 years. Randomization across the groups was done using age and gender stratified randomization method, and the participants were divided into two groups: SPA (n=219, boys: 117, girls: 102) and USPA (n=220, boys: 119, girls: 101). Depending on their training status and gender the participants in both SPA and USPA groups were further subdivided into the following four sub-groups: SPA athlete boys (n=22) and girls (n=17), SPA nonathlete boys (n=95) and girls (n=85), USPA athlete boys (n=23) and girls (n=17), and USPA nonathlete boys (n=96) and girls (n=84). We recorded HRV, body fat%, and VO2 max using Rockport Walk Fitness test before and after the intervention. Maximum aerobic capacity and heart rate variability increased significantly while heart rate, systolic blood pressure, diastolic blood pressure, and body fat percentage decreased significantly after both SPA and USPA intervention. However, the improvement was more in SPA as compared to USPA. SPA is more beneficial for improving cardiorespiratory fitness, HRV, and reducing body fat percentage in terms of
Maier, Silvia U; Hare, Todd A
Higher levels of self-control in decision making have been linked to better psychosocial and physical health. A similar link to health outcomes has been reported for heart-rate variability (HRV), a marker of physiological flexibility. Here, we sought to link these two, largely separate, research domains by testing the hypothesis that greater HRV would be associated with better dietary self-control in humans. Specifically, we examined whether total HRV at sedentary rest (measured as the SD of normal-to-normal intervals) can serve as a biomarker for the neurophysiological adaptability that putatively underlies self-controlled behavior. We found that HRV explained a significant portion of the individual variability in dietary self-control, with individuals having higher HRV being better able to downregulate their cravings in the face of taste temptations. Furthermore, HRV was associated with activity patterns in the ventromedial prefrontal cortex (vmPFC), a key node in the brain's valuation and decision circuitry. Specifically, individuals with higher HRV showed both higher overall vmPFC blood-oxygen-level-dependent activity and attenuated taste representations when presented with a dietary self-control challenge. Last, the behavioral and neural associations with HRV were consistent across both our stress induction and control experimental conditions. The stability of this association across experimental conditions suggests that HRV may serve as both a readily obtainable and robust biomarker for self-control ability across environmental contexts. Self-control is associated with better health, but behavioral and psychometric self-control measures allow only indirect associations with health outcomes and may be distorted by reporting bias. We tested whether resting heart-rate variability (HRV), a physiological indicator of psychological and physical health, can predict individual differences in dietary self-control in humans. We found that higher HRV was associated with
George E Billman
Full Text Available Heart rate variability (HRV, the beat-to-beat variation in either heart rate or the duration of the R-R interval – the heart period, has become a popular clinical and investigational tool. The temporal fluctuations in heart rate exhibit a marked synchrony with respiration (increasing during inspiration and decreasing during expiration – the so called respiratory sinus arrhythmia, RSA and are widely believed to reflect changes in cardiac autonomic regulation. Although the exact contributions of the parasympathetic and the sympathetic divisions of the autonomic nervous system to this variability are controversial and remain the subject of active investigation and debate, a number of time and frequency domain techniques have been developed to provide insight into cardiac autonomic regulation in both health and disease. It is the purpose of this essay to provide an historical overview of the evolution in the concept of heart rate variability. Briefly, pulse rate was first measured by ancient Greek physicians and scientists. However, it was not until the invention of the Physician’s Pulse Watch (a watch with a second hand that could be stopped in 1707 that changes in pulse rate could be accurately assessed. The Rev. Stephen Hales (1733 was the first to note that pulse varied with respiration and in 1847 Carl Ludwig was the first to record RSA. With the measurement of the ECG (1895 and advent of digital signal processing techniques in the 1960’s, investigation of HRV and its relationship to health and disease has exploded. This essay will conclude with a brief description of time domain, frequency domain, and non-linear dynamic analysis techniques (and their limitations that are commonly used to measure heart rate variability.
Simone Fiuza Regaçone
Full Text Available The objective of this study was to evaluate the association between rest heart rate (HR and the components of the auditory evoked-related potentials (ERPs at rest in women. We investigated 21 healthy female university students between 18 and 24 years old. We performed complete audiological evaluation and measurement of heart rate for 10 minutes at rest (heart rate monitor Polar RS800CX and performed ERPs analysis (discrepancy in frequency and duration. There was a moderate negative correlation of the N1 and P3a with rest HR and a strong positive correlation of the P2 and N2 components with rest HR. Larger components of the ERP are associated with higher rest HR.
Wood, C M; Shelton, G
In cannulated trout there was no cholinergic vagal tone as revealed by atropine blockade during normal heart rates. Reductions in heart rate occasionally occurred under normoxia without apparent external stimuli ('spontaneous' bradycardia) and always occurred under environmental hypoxia (hypoxic bradycardia) due to the imposition of significant vagal tone. Direct measurements of cardiac output (Q) during these bradycardias showed that increases in cardiac stroke volume compensated for the falls in heart rate so that total Q remained unchanged or increased slightly. Sudden experimental reductions in arterial blood pressure via blockade of systemic vasomotor tone with yohimbine or via haemorrhage had no effect on heart rate during normal rates, but caused cardioacceleration during both types of bradycardia. These increases in heart rate never exceeded the point of zero vagal tone (normal heart rate) and were largely or wholly due to reductions in endogenous vagal tone. These cardioaccelerations were temporary; spontaneous bradycardia could re-occur at any time, while hypoxic bradycardia always re-occurred if the hypoxic stimulus were maintained. The results are interpreted in terms of a central interaction between the baroreceptor and chemoreceptor reflexes.
de Jong, IC; Sgoifo, A; Lambooij, E; Korte, SM; Blokhuis, HJ; Koolhaas, JM
The effects of social stress on heart rate, heart rate variability and the occurrence of cardiac arrhythmias were studied in 12 growing pigs. Social stress was induced during a good competition test with a pen mate, and subsequently during a resident-intruder test with an unacquainted pig in which
Jong, de I.C.; Sgoifo, A.; Lambooij, E.; Korte, S.M.; Blokhuis, H.J.; Koolhaas, J.M.
The effects of social stress on heart rate, heart rate variability and the occurrence of cardiac arrhythmias were studied in 12 growing pigs. Social stress was induced during a good competition test with a pen mate, and subsequently during a resident-intruder test with an unacquainted pig in which
Vassiliou, Vassilios S; Heng, Ee Ling; Gatehouse, Peter D; Donovan, Jacqueline; Raphael, Claire E; Giri, Shivraman; Babu-Narayan, Sonya V; Gatzoulis, Michael A; Pennell, Dudley J; Prasad, Sanjay K; Firmin, David N
Magnetic resonance imaging (MRI) phantoms are routinely used for quality assurance in MRI centres; however their long term stability for verification of myocardial T1/ extracellular volume fraction (ECV) mapping has never been investigated. Nickel-chloride agarose gel phantoms were formulated in a reproducible laboratory procedure to mimic blood and myocardial T1 and T2 values, native and late after Gadolinium administration as used in T1/ECV mapping. The phantoms were imaged weekly with an 11 heart beat MOLLI sequence for T1 and long TR spin-echo sequences for T2, in a carefully controlled reproducible manner for 12 months. There were only small relative changes seen in all the native and post gadolinium T1 values (up to 9.0 % maximal relative change in T1 values) or phantom ECV (up to 8.3 % maximal relative change of ECV, up to 2.2 % maximal absolute change in ECV) during this period. All native and post gadolinium T2 values remained stable over time with phantoms increasing by 23.9 ms per degree increase and short T1 phantoms increasing by 0.3 ms per degree increase. There was a small absolute increase in ECV of 0.069 % (~0.22 % relative increase in ECV) per degree increase. Variation in heart rate testing showed a 0.13 % absolute increase in ECV (~0.45 % relative increase in ECV) per 10 heart rate increase. These are the first phantoms reported in the literature modeling T1 and T2 values for blood and myocardium specifically for the T1mapping/ECV mapping application, with stability tested rigorously over a 12 month period. This work has significant implications for the utility of such phantoms in improving the accuracy of serial scans for myocardial tissue characterisation by T1 mapping methods and in multicentre work.
Catharina Cornelia Grant
Full Text Available Quantification of cardiac autonomic activity and control via heart rate (HR and heart rate variability (HRV is known to provide prognostic information in clinical populations. Issues with regard to standardisation and interpretation of HRV data make the use of the more easily accessible HR on its own as an indicator of autonomic cardiac control very appealing. The aim of this study was to investigate the strength of associations between an important cardio vascular health metric such as VO2max and the following: HR, HRV indicators and heart rate normalised HRV indicators. A cross sectional descriptive study was done including 145 healthy volunteers aged between 18 and 22 years. HRV was quantified by time domain, frequency domain and Poincaré plot analysis. Indirect VO2max was determined using the Multistage Coopers test. The Pearson correlation coefficient was calculated to quantify the strength of the associations. Both simple linear and multiple stepwise regressions were performed to be able to discriminate between the role of the individual indicators as well as their combined association with VO2max. Only HR, RR interval and pNN50 showed significant (p<0.01, p<0.01 and p=0.03 correlations with VO2max. Stepwise multiple regression indicated that, when combining all HRV indicators the most important predictor of cardio vascular fitness as represented by VO2max, is HR. HR explains 17% of the variation, while the inclusion of HF (high frequency HRV indicator added only an additional 3.1% to the coefficient of determination. Results also showed when testing the normalised indicators, HR explained of the largest percentage of the changes in VO2max (16.5%. Thus HR on its own is the most important predictor of changes in an important cardiac health metric such as VO2max. These results may indicate that during investigation of exercise ability (VO2max phenomena, quantification of HRV may not add significant value.
Alonso-Valerdi, Luz M; Gutiérrez-Begovich, David A; Argüello-García, Janet; Sepulveda, Francisco; Ramírez-Mendoza, Ricardo A
Brain-computer interface (BCI) is technology that is developing fast, but it remains inaccurate, unreliable and slow due to the difficulty to obtain precise information from the brain. Consequently, the involvement of other biosignals to decode the user control tasks has risen in importance. A traditional way to operate a BCI system is via motor imagery (MI) tasks. As imaginary movements activate similar cortical structures and vegetative mechanisms as a voluntary movement does, heart rate variability (HRV) has been proposed as a parameter to improve the detection of MI related control tasks. However, HR is very susceptible to body needs and environmental demands, and as BCI systems require high levels of attention, perceptual processing and mental workload, it is important to assess the practical effectiveness of HRV. The present study aimed to determine if brain and heart electrical signals (HRV) are modulated by MI activity used to control a BCI system, or if HRV is modulated by the user perceptions and responses that result from the operation of a BCI system (i.e., user experience). For this purpose, a database of 11 participants who were exposed to eight different situations was used. The sensory-cognitive load (intake and rejection tasks) was controlled in those situations. Two electrophysiological signals were utilized: electroencephalography and electrocardiography. From those biosignals, event-related (de-)synchronization maps and event-related HR changes were respectively estimated. The maps and the HR changes were cross-correlated in order to verify if both biosignals were modulated due to MI activity. The results suggest that HR varies according to the experience undergone by the user in a BCI working environment, and not because of the MI activity used to operate the system.
Farina, Benedetto; Dittoni, Serena; Colicchio, Salvatore; Testani, Elisa; Losurdo, Anna; Gnoni, Valentina; Di Blasi, Chiara; Brunetti, Riccardo; Contardi, Anna; Mazza, Salvatore; Della Marca, Giacomo
Chronic insomnia is highly prevalent in the general population, provoking personal distress and increased risk for psychiatric and medical disorders. Autonomic hyper-arousal could be a pathogenic mechanism of chronic primary insomnia. The aim of this study was to investigate autonomic activity in patients with chronic primary insomnia by means of heart rate variability (HRV) analysis. Eighty-five consecutive patients affected by chronic primary insomnia were enrolled (38 men and 47 women; mean age: 53.2 ± 13.6). Patients were compared with a control group composed of 55 healthy participants matched for age and gender (23 men and 32 women; mean age: 54.2 ± 13.9). Patients underwent an insomnia study protocol that included subjective sleep evaluation, psychometric measures, and home-based polysomnography with evaluation of HRV in wake before sleep, in all sleep stages, and in wake after final awakening. Patients showed modifications of heart rate and HRV parameters, consistent with increased sympathetic activity, while awake before sleep and during Stage-2 non-REM sleep. No significant differences between insomniacs and controls could be detected during slow-wave sleep, REM sleep, and post-sleep wake. These results are consistent with the hypothesis that autonomic hyper-arousal is a major pathogenic mechanism in primary insomnia, and confirm that this condition is associated with an increased cardiovascular risk.
Corotto, Frank; Ceballos, Darrel; Lee, Adam; Vinson, Lindsey
Students commonly test the effects of chemical agents on the heart rate of the crustacean "Daphnia" magna, but the procedure has never been optimized. We determined the effects of three concentrations of ethanol, nicotine, and caffeine and of a control solution on heart rate in "Daphnia." Ethanol at 5% and 10% (v/v) reduced mean heart rate to…
Boudet, G; Garet, M; Bedu, M; Albuisson, E; Chamoux, A
The objective of this study was to evaluate the variability of maximal heart rate in three different conditions: laboratory tests, field tests, and competitions. Sixteen male endurance volunteers were tested in five exhaustive tests for each condition. All exhaustive events were heart rate monitored (Accurex plus, Polar Electro, Finland) and true maximal heart rates were assessed and compared with each other and with predicted maximal heart rates. Results show that under the three conditions HR(peaks) were not statistically different (p = 0.62, NS, Friedman test). Mean HR(peaks) (SD) were: laboratory = 194.3 (7.8), field = 193.8 (11.8), competition = 192.3 (10.1) beats x min(-1). Conditions for reaching individual heart rate peak were in the laboratory (treadmill VO(2)max protocol) for 5 subjects, in field tests for 7 subjects and in competitions for 6 subjects (two circumstances for two subjects). A large intra-individual variation existed in the three circumstances (+/- 6 beats x min(-1)). Absolute median maximal heart rate was 190.0 bpm (9.32) i.e 7.6 bpm lower than heart rate peak. Both were highly related (rho = 0.89, z = 3.449, p = 0.0006, Spearman test). Median maximal heart rates inter-condition relationship were higher. Median maximal heart rate was more stable and took more information into account than an isolated peak. It gives a central value that minimizes the potential risk of under or over estimation when calibrating exercise intensities with HR.
Full Text Available Heart rate variability (HRV is an important measure of sympathetic and parasympathetic functions of the autonomic nervous system and a key indicator of cardiovascular condition. This paper proposes a novel method to investigate HRV, namely by modelling it as a linear combination of Gaussians. Results show that three Gaussians are enough to describe the stationary statistics of heart variability and to provide a straightforward interpretation of the HRV power spectrum. Comparisons have been made also with synthetic data generated from different physiologically based models showing the plausibility of the Gaussian mixture parameters.
González Landaeta, R; Casas, O; Pallàs-Areny, R
The heart rate is a basic health indicator, useful in both clinical measurements and home health care. Current home care systems often require the attachment of electrodes or other sensors to the body, which can be cumbersome to the patient. Moreover, some measurements are sensitive to movement artifacts, are not user-friendly and require a specialized supervision. In this paper, a novel technique for heart rate measurement for a standing subject is proposed, which is based on plantar bioimpedance measurements, such as those performed by some bathroom weighting scales for body composition analysis. Because of the low level of heart-related impedance variations, the measurement system has a gain of 1400. We have implemented a fully differential AC amplifier with a common-mode rejection ratio (CMRR) of 105 dB at 10 kHz. Coherent demodulation based on synchronous sampling yields a signal-to-noise ratio (SNR) of 55 dB. The system has a sensitivity of 1.9 V/Omega. The technique has been demonstrated on 18 volunteers, whose bioimpedance signal and ECG were simultaneously measured to validate the results. The average cross-correlation coefficient between the heart rates determined from these two signals was 0.998 (std. dev. 0.001).
Full Text Available Choir singing is known to promote wellbeing. One reason for this may be that singing demands a slower than normal respiration which may in turn affect heart activity. Coupling of heart rate variability (HRV to respiration is called Respiratory sinus arrhythmia (RSA. This coupling has a subjective as well as a biologically soothing effect, and it is beneficial for cardiovascular function. RSA is seen to be more marked during slow-paced breathing and at lower respiration rates (0.1 Hz and below. In this study, we investigate how singing, which is a form of guided breathing, affects HRV and RSA. The study comprises a group of healthy 18 year olds of mixed gender. The subjects are asked to; (1 hum a single tone and breathe whenever they need to; (2 sing a hymn with free, unguided breathing; and (3 sing a slow mantra and breathe solely between phrases. Heart rate (HR is measured continuously during the study. The study design makes it possible to compare above three levels of song structure. In a separate case study, we examine five individuals performing singing tasks (1-(3. We collect data with more advanced equipment, simultaneously recording HR, respiration, skin conductance and finger temperature. We show how song structure, respiration and heart rate are connected. Unison singing of regular song structures makes the hearts of the singers accelerate and decelerate simultaneously. Implications concerning the effect on wellbeing and health are discussed as well as the question how this inner entrainment may affect perception and behavior.
Kirkpatrick, Beth; Birnbaum, Burton H.
Learning about the relationship between heart rate and physical activity is an important aspect of fitness education. Use of a heart rate monitor (HRM) helps a student to understand how stretching and large muscle movements gradually increase the heart rate and blood flow, and enables students to measure their exercise heart rates and set goals…
Reardon, M; Malik, M
Depressed heart rate variability (HRV) after a myocardial infarction is associated with increased mortality. This is thought to be due to reduced parasympathetic activity and heightened sympathetic activity. Aging is associated with depressed HRV, but little is known of the affect of aging on parasympathetic activity. This study examined 56 healthy subjects (age range 40-102 years; 39 women). None had a history of heart disease or were on medication that would affect cardiac function. All had normal resting ECGs, normal heart size on chest X ray, and normal electrolytes. In all subjects, 24-hour Holter recordings were performed and used to measure HRV. In particular, the study examined the affect of age on HRV triangular index, which gives an estimate of overall HRV, and on RMSSD (square root of the mean squared differences of successive normal-to-normal RR intervals), which gives an estimate of short-term components of HRV and is thought to reflect the overall extent of vagal modulations of heart rates. Both these parameters were compared in patients younger and older than 70 years. Each recording lasted at least 17 hours; the majority of recordings were longer than 20 hours. There was a significant decrease in HRV triangular index with age (r = -0.4, P 70 years compared with those < 70 years (38.0 +/- 9.3 vs 31.0 +/- 11, respectively, P < 0.02). There was no significant difference in RMSSD between the two age groups (26.7 +/- 8.2 ms vs 28.4 +/- 11.3 ms, respectively, P = NS). Thus, the study concludes that aging reduces the global measure of HRV and may reflect reduced responsiveness of autonomic activity to external environmental stimuli with age. However, the time-domain short-term components of HRV are not affected by age and, therefore, the fast and presumably vagal modulations of heart rate appear to be maintained.
Cottin, François; Durbin, François; Papelier, Yves
This study compared heart rate variability (HRV) in ten male judokas between two types of exercise eliciting the same near-maximal average heart rate (HR): judo wrestling vs. cycloergometric bout. Beat-to-beat RR intervals were recorded during (1) a 4-min judo randori (wrestling); (2) a 4-min cycloergometric exercise eliciting maximal oxygen consumption (VO(2MAX)). Time series were analyzed both by short term Fourier transform (STFT) and Poincaré plot (PP). The main results are as follows. First, despite the fact that the same maximal HR was reached during the two exercises, the spectral energy computed from the judo recordings was significantly higher than that recorded from the cycloergometric exercise. Second, according to the PP index of rapid HRV (SD1), the high-frequency spectral energy (HF) was significantly higher during judo than cycloergometric exercise as well. Third, judo spectra show chaotic harmonics in place of the precise HF peak observed during cycloergometric exercise. Fourth, the respective parts of normalized LFn and HFn are not different between the two exercise modes, suggesting that autonomic control during severe exercise cannot depend on the type of exercise. In conclusion, this study shows that it is possible, according to the observed kind of variability from RR time series, to differentiate between two types of effort: steady-state dynamic exercise or conversely exercise made of both isometric and irregular dynamic efforts (wrestling, collective sports, and others).
Karlsson, Björn-Markus; Lindkvist, Marie; Lindkvist, Markus; Karlsson, Marcus; Lundström, Ronnie; Håkansson, Stellan; Wiklund, Urban; van den Berg, Johannes
Aim: To measure the effect of sound and whole-body vibration on infants' heart rate and heart rate variability during ground and air ambulance transport. Methods: Sixteen infants were transported by air ambulance with ground ambulance transport to and from the airports. Whole-body vibration and sound levels were recorded and heart parameters were obtained by ECG signal. Results: Sound and whole-body vibration levels exceeded the recommended limits. Mean whole-body vibration and sound levels w...
Tonhajzerova, Ingrid; Farsky, Ivan; Mestanik, Michal; Visnovcova, Zuzana; Mestanikova, Andrea; Hrtanek, Igor; Ondrejka, Igor
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.
Escher, J; Evéquoz, D
The effect of trophotropic (relaxing) music on heart rate and heart rate variability has been investigated in 23 healthy young individuals by means of 24-hour Holter-ECG. Relaxing music (Bach, Vivaldi, Mozart) resulted in significant reduction of heart rate and also significant reduction of heart rate variability. The significance of these results for the use of music in coronary heart disease is discussed.
Buxton, R. E.; West, M. R.; Kalogera, K. L.; Hanson, A. M.
Heart rate monitoring is required for crewmembers during exercise aboard the International Space Station (ISS) and will be for future exploration missions. The cardiovascular system must be sufficiently stressed throughout a mission to maintain the ability to perform nominal and contingency/emergency tasks. High quality heart rate data are required to accurately determine the intensity of exercise performed by the crewmembers and show maintenance of VO2max. The quality of the data collected on ISS is subject to multiple limitations and is insufficient to meet current requirements. PURPOSE: To evaluate the performance of commercially available Bluetooth heart rate monitors (BT_HRM) and their ability to provide high quality heart rate data to monitor crew health aboard the ISS and during future exploration missions. METHODS: Nineteen subjects completed 30 data collection sessions of various intensities on the treadmill and/or cycle. Subjects wore several BT_HRM technologies for each testing session. One electrode-based chest strap (CS) was worn, while one or more optical sensors (OS) were worn. Subjects were instrumented with a 12-lead ECG to compare the heart rate data from the Bluetooth sensors. Each BT_HRM data set was time matched to the ECG data and a +/-5bpm threshold was applied to the difference between the 2 data sets. Percent error was calculated based on the number of data points outside the threshold and the total number of data points. RESULTS: The electrode-based chest straps performed better than the optical sensors. The best performing CS was CS1 (1.6% error), followed by CS4 (3.3% error), CS3 (6.4% error), and CS2 (9.2% error). The OS resulted in 10.4% error for OS1 and 14.9% error for OS2. CONCLUSIONS: The highest quality data came from CS1, but unfortunately it has been discontinued by the manufacturer. The optical sensors have not been ruled out for use, but more investigation is needed to determine how to obtain the best quality data. CS2 will be
Thongkongoum, W.; Boonduang, S.; Limsuwan, P.
Heart rate monitoring via optically remote noncontact technique was reported in this research. A green laser (5 mW, 532±10 nm) was projected onto the left carotid artery. The reflected laser light on the screen carried the deviation of the interference patterns. The interference patterns were recorded by the digital camera. The recorded videos of the interference patterns were frame by frame analysed by 2 standard digital image processing (DIP) techniques, block matching (BM) and optical flow (OF) techniques. The region of interest (ROI) pixels within the interference patterns were analysed for periodically changes of the interference patterns due to the heart pumping action. Both results of BM and OF techniques were compared with the reference medical heart rate monitoring device by which a contact measurement using pulse transit technique. The results obtained from BM technique was 74.67 bpm (beats per minute) and OF technique was 75.95 bpm. Those results when compared with the reference value of 75.43±1 bpm, the errors were found to be 1.01% and 0.69%, respectively.
Wasilewski, G; Przybyłowski, P; Janik, L; Nowak, E; Sadowski, J; Małyszko, J
Renalase may degrade catecholamines and regulate sympathetic tone and blood pressure. The aim of this study was to assess dopamine, norepinephrine, and renalase in 80 heart transplant recipients and 22 healthy volunteers and their correlations with heart rate, blood pressure control, type of hypotensive therapy, and renal function. Renalase, dopamine, and norepinephrine were studied by using commercially available assays. Renalase levels were higher in heart transplant recipients compared with healthy volunteers, and noradrenaline levels were lower in the studied cohort patients than in the healthy volunteers. Noradrenaline was correlated with white blood cell count (r = -0.21, P noradrenaline nor dopamine was correlated with heart rate, blood pressure, kidney function, or New York Heart Association class. Noradrenaline was significantly higher in patients with elevated diastolic blood pressure (>90 mm Hg) compared with those with normal diastolic blood pressure (P < .05). Renalase was related to kidney function but was unrelated to catecholamines. Elevated renalase levels in heart transplant patients were related to kidney function but not linked to the sympathetic nervous system activity in this study population. In heart transplant recipients, these findings might suggest that sympathetic denervation and the modulation of β-receptors persist.
Full Text Available Heart Rate Variability studies are a known measure for the autonomous control of the heart rate. In special situations, its interpretation can be ambiguous, since the respiration has a major influence on the heart rate variability. For this reason it has often been proposed to measure Heart Rate Variability, while the subjects are breathing at a constant respiration rate. That way the spectral influence of the respiration is known. In this work we propose to remove this constant respiratory influence from the heart rate and the Heart Rate Variability parameters to gain respiration free autonomous controlled heart rate signal. The spectral respiratory component in the heart rate signal is detected and characterized. Subsequently the respiratory effect on Heart Rate Variability is removed using spectral filtering approaches, such as the Notch filter or the Raised Cosine filter. As a result new decoupled Heart Variability parameters are gained, which could lead to new additional interpretations of the autonomous control of the heart rate.
Zarei, M; Ghoddusi, J; Sharifi, E; Forghani, M; Afkhami, F; Marouzi, Parviz
To compare the efficacy of supplemental anaesthesia using periodontal ligament injections (PDL) and intraosseous injections with the X-Tip system in terms of the measured heart rate and patient reported pain level. In this single-blind randomized clinical trial, 40 patients (22 women, 18 men) with irreversible pulpitis who had experienced unsuccessful pain management by inferior alveolar nerve block with 2% lidocaine and 1 : 100 000 epinephrine were selected. Patients were divided equally and randomly into two groups. Supplementary anaesthesia was provided through intraosseous injection with the X-Tip system (X-Tip group) or by PDL injection (PDL group). After each step of injection, pain severity was assessed using a visual analogue scale. Patient heart rate was recorded with a pulse oximeter. Data were coded and analysed using Mann-Whitney U-test with SPSS (version 16) software. Anaesthetic success was obtained in 100% of X-Tip and 70% of PDL group patients after the first supplemental injection. Compared with the first PDL injection, the first intraosseous injection resulted in a significant increase in heart rate (P = 0.001); however, this increase was short-lived (mean increase: 9-10 beats per min). No significant difference in heart rate or anaesthesia success was observed between men and women. Intraosseous injection using the X-Tip system was more effective than PDL injection as a supplementary anaesthetic for pulpectomy in mandibular molars or second premolars. However, the former resulted in a transient increase in heart rate. © 2012 International Endodontic Journal.
Yang, Tianlun; Jiang, Yinong; Hao, Yuming; Zhou, Shuxian; Xu, Xinjuan; Qu, Baiming; Lin, Xue; Ma, Tianrong
This open-label study investigated the long action of bisoprolol compared with metoprolol CR/ZOK for controlling the mean dynamic heart rate (HR) and blood pressure (BP) in patients with mild-to-moderate primary hypertension. Patients from seven centers in China were treated with either bisoprolol 5 mg or metoprolol CR/ZOK 47.5 mg once daily for 12 weeks. The primary end points were the mean dynamic HR reduction and the mean dynamic diastolic BP (DBP) control in the last 4 h of the treatment period. Secondary end points included ambulatory monitoring of the BP and HR, safety and compliance. A total of 186 patients, with 93 patients in each group, were enrolled and analyzed. In the last 4 h of the treatment period, patients receiving bisoprolol demonstrated a significantly greater reduction in the mean dynamic HR compared with patients receiving metoprolol CR/ZOK (least squares means (LSmeans) of difference: -3.79 b.p.m.; 97.5% confidence interval (CI): -7.45, -0.14; P=0.0202). Furthermore, in the last 4 h of the treatment period, bisoprolol demonstrated non-inferiority vs. metoprolol CR/ZOK in lowering the mean dynamic DBP (LSmeans of difference: -1.00; 97.5% CI: -4.79, 2.78; P=0.5495). Bisoprolol further significantly lowered the 24-h mean ambulatory, mean daytime and mean nighttime HR. The overall adverse event rate was similar between the two groups. Noncompliance was reported in 3 (3.53%) and 6 (7.32%) patients in the bisoprolol and metoprolol CR/ZOK groups, respectively. In conclusion, bisoprolol provided superior dynamic HR reduction and non-inferior dynamic BP reduction vs. metoprolol CR/ZOK in patients with mild-to-moderate hypertension. No new safety concerns were found.
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.
Giraldo Giraldo, Beatriz; Téllez, Joan P.; Herrera, Sergio; Benito, Salvador
Assessment of the dynamic interactions between cardiovascular signals can provide valuable information that improves the understanding of cardiovascular control. Heart rate variability (HRV) analysis is known to provide information about the autonomic heart rate modulation mechanism. Using the HRV signal, we aimed to obtain parameters for classifying patients with and without chronic heart failure (CHF), and with periodic breathing (PB), non-periodic breathing (nPB), and Cheyne-Stokes respira...
Yee, J.; Parboosingh, I.J.
Subtle changes in the characteristics of the fetal heart rate are currently used to assess the condition of the fetus in late pregnancy and during labour. The authors present three case studies of fetal heart rate monitoring.
Monfredi, Oliver; Lyashkov, Alexey E; Johnsen, Anne-Berit; Inada, Shin; Schneider, Heiko; Wang, Ruoxi; Nirmalan, Mahesh; Wisloff, Ulrik; Maltsev, Victor A; Lakatta, Edward G; Zhang, Henggui; Boyett, Mark R
Heart rate variability (beat-to-beat changes in the RR interval) has attracted considerable attention over the last 30+ years (PubMed currently lists >17,000 publications). Clinically, a decrease in heart rate variability is correlated to higher morbidity and mortality in diverse conditions, from heart disease to foetal distress. It is usually attributed to fluctuation in cardiac autonomic nerve activity. We calculated heart rate variability parameters from a variety of cardiac preparations (including humans, living animals, Langendorff-perfused heart and single sinoatrial nodal cell) in diverse species, combining this with data from previously published papers. We show that regardless of conditions, there is a universal exponential decay-like relationship between heart rate variability and heart rate. Using two biophysical models, we develop a theory for this, and confirm that heart rate variability is primarily dependent on heart rate and cannot be used in any simple way to assess autonomic nerve activity to the heart. We suggest that the correlation between a change in heart rate variability and altered morbidity and mortality is substantially attributable to the concurrent change in heart rate. This calls for re-evaluation of the findings from many papers that have not adjusted properly or at all for heart rate differences when comparing heart rate variability in multiple circumstances. PMID:25225208
Waldeck, Miriam R.; Lambert, Michael I.
Resting heart rate has sometimes been used as a marker of training status. It is reasonable to assume that the relationship between heart rate and training status should be more evident during sleep when extraneous factors that may influence heart rate are reduced. Therefore the aim of the study was to assess the repeatability of monitoring heart rate during sleep when training status remained unchanged, to determine if this measurement had sufficient precision to be used as a marker of train...
Dursun, Huseyin; Onrat, Ersel; Ercan, Emine; Demirdal, Umit Secil; Avsar, Alaettin; Dundar, Umit; Solak, Ozlem; Toktas, Hasan
Fibromyalgia is characterized by diffuse musculoskeletal pain and discomfort. There are several reports regarding autonomic nervous system dysfunction in patients with fibromyalgia. Heart rate turbulence is expressed as ventriculophasic sinus arrhythmia and has been considered to reflect cardiac autonomic activity. Heart rate turbulence has been shown to be an independent and powerful predictor of sudden cardiac death in various cardiac abnormalities. The aim of this study is to determine whether heart rate turbulence is changed in female patients with fibromyalgia compared with healthy controls. Thirty-seven female patients (mean age, 40±11 years) with fibromyalgia, and 35 age- and sex-matched healthy female control subjects (mean age, 42±9 years) were included. Twenty-four hours of ambulatory electrocardiography recordings were collected for all subjects, and turbulence onset and turbulence slope values were automatically calculated. The baseline clinical characteristics of the two groups were similar. There were no significant differences in turbulence onset and turbulence slope measures between patients and control subjects (turbulence onset: -1.648±1.568% vs. -1.582±1.436%, p ϝ 0.853; turbulence slope: 12.933±5.693 ms/RR vs. 13.639±2.505 ms/RR, p ϝ 0.508). Although body mass index was negatively correlated with turbulence slope (r ϝ -0.258, p ϝ 0.046), no significant correlation was found between body mass index and turbulence onset (r ϝ 0.228, p ϝ 0.054). To the best of our knowledge, this is the first study to evaluate heart rate turbulence in patients with fibromyalgia. It appears that heart rate turbulence parameters reflecting cardiac autonomic activity are not changed in female patients with fibromyalgia.
Jing, Xiaolu; Wu, Ping; Liu, Fang; Wu, Bin; Miao, Danmin
Centrifuge training is an important method of improving the hypergravity tolerance of pilots, cosmonauts, and Chinese astronauts. However, the concomitants of tension or anxiety often impede training. Guided imagery (GI), a mind-body relaxation technique, provides a behavioral and cognitive means whereby individuals are able to exert control over the focus of attention. This study aims to investigate the immediate effects of GI for reducing stress in centrifuge training. There were 12 healthy young men who were randomly assigned to a GI group or music group. We measured changes in heart rate during centrifuge training, in heart rate variability before and after centrifuge training, and also evaluated relaxation and anxiety in three phases: before intervention, after intervention, and following centrifuge training. The change in the pattern of anxiety was different in the two groups over the three phases. Anxiety (measured by State Anxiety Inventory) in the GI group changed from 31.7 +/- 5.9 to 26.8 +/- 2.6 and 27.8 +/- 4.1, whereas for the music group this changed from 32.2 +/- 7.6 to 31.2 +/- 8.3 and 26.8 +/- 6.8. During centrifuge training, the maximal HR for the GI group (101.2 +/- 8.8) was lower than that of the music group (123.0 +/- 19.1). In addition GI showed a decrease in low frequency (LF, 0.04-0.15 Hz) components and an increase in high frequency (HF, 0.15-0.4 Hz) components before and after centrifuge training. GI was capable of decreasing tension, anxiety, and sympathetic nervous system activity pre- or post-centrifugation.
Review: Resting heart rate and cardiovascular events: risk factor or risk marker? 128. Vol 52 No 2. SA Fam Pract 2010. SA Fam Pract 2010;52(2): 128-129. Heart rate in epidemiological studies. Over the last 25 years numerous reports demonstrated a significant association between resting heart rate and all- cause mortality ...
Koers, G.; Mulder, L.J.M.; van der Veen, F.M.
For many years psychophysiologists have been interested in stimulus related changes in heart rate and blood pressure. To represent these evoked heart rate and blood pressure patterns, heart rate and blood pressure data have to be transformed into equidistant time series. This paper presents an
Ivanova, Iana A; Danilenko, Konstantin V; Aftanas, Lyubomir I
Body (fat) mass has been shown to decrease following bright light treatment for overweight women, irrespective of their seasonal (light) dependence. It is not known if this is due to an (immediate) increase of metabolism. Ten women with seasonal affective disorder (SAD) and 10 non-SAD women matched by age, body mass index, and menopausal status participated in a laboratory study in the morning, twice within 1-5 days. During one session, bright light (4,300 lx) was presented for 30 min, and during the other session, red light (250 lx "placebo") was used. After an initial 15 min of sitting quietly in an experimental chamber, 10-min measurements were done before, at the end, and 15 min after light exposure; the subjects remained seated for 80 min in total. The measurements included 5-min oxyspirography (oxygen consumption, carbon dioxide emission, and heart rate), saliva sampling for the estimation of cortisol and α-amylase concentrations, and self-rating of mood, energy, and sleepiness. There was no light-specific effect on the measured variables, except that sleepiness was reduced more with bright light than with red light in the combined group. α-Amylase values were lower in the SAD patients than in the non-SAD controls. Morning artificial bright light, in comparison with dim red light, had no immediate effect on metabolism and resting sympathetic tone, though subjective sleepiness decreased more with bright light. SAD patients have low salivary α-amylase levels, indicating lower sympathetic tone. © 2017 S. Karger AG, Basel.
Dickhaus, Hartmut; Maier, Christoph; Khalil, Markus; Ulmer, Herbert
This study aims at characterizing the short-term time-courses of time- and frequency-domain heart rate variability (HRV) parameters during head-up tilt test (HUTT). Data from 44 young patients with a history of syncope and 34 age-matched controls was analysed in two age-groups related to puberty ( or =14 years), and separately for gender, by extracting minute-by-minute progression of mean RR-interval, standard deviation of RR-intervals (SDNN) and their first difference (SDSD) as well as low-frequency (LF, 0.05-0.15 Hz) energy, high-frequency (HF, 0.15-0.4 Hz) energy and the LF/HF-ratio. Time-courses were individually normalized and averaged after synchronization to the events of tilt and tilt-back/syncope. We observed remarkable age-related differences not only with respect to response to tilting but also regarding the differentiation of patients with positive HUTT from controls with negative HUTT. ROC-analysis in three regions of interest (0-2 min after tilt, 2-5 min after tilt, 5-2 min before tilt-back) revealed generally much weaker and less persistent differences in younger subjects whereas in elders the differences were clearer and often most pronounced immediately before syncope. For both age-groups, the relative change of mean RR provided best separation, however in elders in the ROI just before syncope (sensitivity: 74%, specificity 80%) in young immediately after tilt (sens.: 71%, spec.: 74%). In elder subjects, the relative reduction of SDNN 2-5 minute after tilt achieved almost the same performance (sens.: 74%, spec. 80%) as in the ROI before syncope (sens. 78%, spec. 73%), indicating the existence of rather early precursors of syncope that might help to predict the outcome of the HUTT in subjects in or after puberty.
Russell, Noirin E; Higgins, Mary F; Kinsley, Brendan F; Foley, Michael E; McAuliffe, Fionnuala M
Cardiomyopathy is a common finding in offspring of pre-gestational type 1 diabetic pregnancy. Echocardiographic and biochemical evidence of fetal cardiac dysfunction have also been reported. Studies suggest that offspring of diabetic mothers (ODM) undergo a fetal programming effect due to the hyperglycaemic intrauterine milieu which increases their risk of cardiovascular morbidity in adult life. Decreased neonatal heart rate variability (HRV) has been described in association with in-utero growth restriction, prematurity, sudden infant death syndrome and congenital heart disease. The effect of in-utero exposure to hyperglycaemia in diabetic pregnancy on neonatal HRV is unknown. Our aim was to determine if neonatal HRV differs between normal and diabetic pregnancy. This was a prospective observational study of 38 patients with pregestational type 1 diabetes and 26 controls. HRV assessment was performed using Powerlab (ADI Instruments Ltd). Heart rate variability assessment and cord blood sampling for pH and glucose were performed for all neonates. Maternal glycaemic control was assessed via measurement of glycosylated haemoglobin in each trimester in the diabetic cohort. Neonates of diabetic mothers had evidence of altered heart rate variability, with increased low frequency to high frequency ratio (LF: HF), suggestive of a shift towards sympathetic predominance (pheart to fluctuations in maternal glycaemia with subsequent alterations in HRV may explain why infants of diabetic mothers are at greater risk of cardiovascular disease in later life. Copyright © 2015. Published by Elsevier Ireland Ltd.
Hewett, Zoe L.; Pumpa, Kate L.; Smith, Caroline A.; Fahey, Paul P.; Birinder S. Cheema
Background Chronic activation of the stress-response can contribute to cardiovascular disease risk, particularly in sedentary individuals. This study investigated the effect of a Bikram yoga intervention on the high frequency power component of heart rate variability (HRV) and associated cardiovascular disease (CVD) risk factors (i.e. additional domains of HRV, hemodynamic, hematologic, anthropometric and body composition outcome measures) in stressed and sedentary adults. Methods Eligible ad...
VANSTEENIS, HG; TULEN, JHM; MULDER, LJM
This paper compares two methods to estimate heart rate variability spectra i.e., the spectrum of counts and the instantaneous heart rate spectrum. Contrary to Fourier techniques based on equidistant sampling of the interbeat intervals, the spectrum of counts of the instantaneous heart rate spectrum
Robert Lake Conder
Full Text Available The study of Heart Rate Variability (HRV has emerged as an essential component of cardiovascular health, as well as a physiological mechanism by which one can increase the interactive communication between the cardiac and the neurocognitive systems (i.e., the body and the brain. It is well-established that lack of heart rate variability implies cardiopathology, morbidity, reduced quality-of-life, and precipitous mortality. On the positive, optimal heart rate variability has been associated with good cardiovascular health, autonomic nervous system (ANS control, emotional regulation, and enhanced neurocognitive processing. In addition to health benefits, optimal HRV has been shown to improve neurocognitive performance by enhancing focus, visual acuity and readiness, and by promoting emotional regulation needed for peak performance. In concussed athletes and soldiers, concussions not only alter brain connectivity, but also alter cardiac functioning and impair cardiovascular performance upon exertion. Altered sympathetic and parasympathetic balance in the ANS has been postulated as a critical factor in refractory Post Concussive Syndrome (PCS. This article will review both the pathological aspects of reduced heart rate variability on athletic performance, as well as the cardiovascular and cerebrovascular components of concussion and PCS. Additionally, this article will review interventions with HRV biofeedback (HRV BFB training as a promising and underutilized treatment for sports and military-related concussion. Finally, this article will review research and promising case studies pertaining to use of HRV BFB for enhancement of cognition and performance, with applicability to concussion rehabilitation.
Jeukendrup, A; VanDiemen, A
To obtain optimal training effects and avoid overtraining, it is necessary to monitor the intensity of training. In cycling, speed is not an accurate indicator of exercise intensity, and therefore alternatives have to be found to monitor exercise intensity during training and competition. Power output may be the most direct indicator, but heart rate is easier to monitor and measure. There are, however, limitations that have to be taken into account when using a heart rate monitor. For example, the position on the bicycle may change heart rate at a given exercise intensity. More important, however, is the increase in heart rate over time, a phenomenon described as 'cardiac drift'. Cardiac drift can change the heart rate-power output relationship drastically, especially in hot environments or at altitude. It is important to determine whether one is interested in monitoring exercise intensity per se or measuring whole-body stress. Power output may be a better indicator of the former and heart rate may, under many conditions, be a better indicator of the latter. Heart rate can be used to evaluate a cyclist after training or competition, or to determine the exercise intensity during training. Heart rate monitoring is very useful in the detection of early overtraining, especially in combination with lactate curves and questionnaires. During overtraining, maximal heart rates as well as submaximal heart rates may be decreased, while resting and, in particular, sleeping - heart rates may be increased.
Thomas, R M; Algrain, H A; Ryan, E J; Popojas, A; Carrigan, P; Abdulrahman, A; Carrillo, A E
Proposed differences in caffeine metabolism due to the CYP1A2*1F polymorphism have been linked to variations in cardiovascular disease risk. We examined the influence of a CYP1A2*1F polymorphism on post-exercise heart rate variability (HRV) in response to caffeine intake. Volunteers were identified as A/A homozygotes (A/A; 4 females and 7 males; age: 25.3 ± 4.1 years; BMI: 25.9 ± 4.4 kg/m2) or C allele carriers (C allele; 3 females and 6 males; age: 25.5 ± 2.8 years; BMI: 26.6 ± 5.0 kg/m2) for participation in a repeated measures, counterbalanced, double-blind, placebo-controlled trial. Participants chewed three pieces of gum containing either caffeine (CAF) (100 mg/piece) or placebo for 5 min. Thereafter, participants cycled for 15 min at 75 % of their peak oxygen consumption. Eight HRV indices computed during 5 min at baseline (BASE), 0-5 min after exercise (POST1), and 5-10 min after exercise (POST2) were used for analysis. No significant group differences were detected in HRV indices at BASE, POST1, or POST2 during both trials (p > 0.05). Rate of recovery (POST2-POST1) for the square root of the mean of squared differences between successive RR intervals (RMSSD) was significantly different between A/A (6.0 ± 2.5 ms) and C allele (3.6 ± 2.5 ms) groups during the CAF trial (p = 0.048). Rate of RMSSD recovery was the only variable influenced by the CYP1A2*IF polymorphism during post-exercise in response to caffeine intake. Thus, the CYP1A2*1F polymorphism did not overtly influence the effects of caffeine intake on post-exercise HRV.
Martuscelli, Eugenio; Romagnoli, Andrea; D'eliseo, Alessia; Sperandio, Massimiliano; Di Luozzo, Marco; De Angelis, Barbara; Romeo, Francesco; Simonetti, Giovanni
Imaging artifacts due to metallic stent struts can reduce the diagnostic accuracy of multislice computed tomography (MSCT) in the evaluation of in-stent restenosis (ISR). Our aim was to determine the accuracy of binary ISR exclusion using a 64-slice MSCT scanner and a systematic administration of beta-blockers having an aggressive heart rate (HR) control. We performed 64-slice MSCT in 218 consecutive patients revascularized by stenting. All patients were treated with oral/intravenous beta-blocker drugs in order to obtain a HR less than 65 beats/min in the prescan phase. Coronary stents were evaluated by two experienced observers in order to rule out the presence of significant (>50%) ISR. Quantitative conventional coronary angiography (CCA) served as a standard for reference. Five patients (2.3%) were excluded from the analysis; mean HR was 59 +/- 3 beats/min in the prescan phase and 62 +/- 5 beats/min during acquisition. In the 321 stented coronary segments, CCA found 27 significant ISRs. MSCT correctly diagnosed 26 significant ISRs, with two false-positive and one false-negative case. In a per-segment analysis, the sensitivity was 96%, specificity 99%, positive predictive value (PPV) 92.8%, and negative predictive value (NPV) 99%. In a per-patient analysis, the sensitivity was 100%, specificity 98.9%, PPV 92.8%, and NPV 100%. In our study, the evaluation of significant ISR by MSCT showed an excellent diagnostic accuracy with a PPV of 92.8% and a NPV of 99%. Selection criteria and radiation exposure can be considered a limitation of the method.
Full Text Available Mild cognitive impairment (MCI is set to become a major health problem with the exponential ageing of the world's population. The association between MCI and autonomic dysfunction, supported by indirect evidence and rich with clinical implications in terms of progression to dementia and increased risk of mortality and falls, has never been specifically demonstrated.To conduct a comprehensive assessment of autonomic function in subjects with MCI by means of power spectral analysis (PSA of heart rate variability (HRV at rest and during provocative manoeuvres.This cross-sectional study involved 80 older outpatients (aged ≥ 65 consecutively referred to a geriatric unit and diagnosed with MCI or normal cognition (controls based on neuropsychological testing. PSA was performed on 5-minute electrocardiographic recordings under three conditions--supine rest with free breathing (baseline, supine rest with paced breathing at 12 breaths/minute (parasympathetic stimulation, and active standing (orthosympathetic stimulation--with particular focus on the changes from baseline to stimulation of indices of sympathovagal balance: normalized low frequency (LFn and high frequency (HFn powers and the LF/HF ratio. Blood pressure (BP was measured at baseline and during standing. Given its exploratory nature in a clinical population the study included subjects on medications with a potential to affect HRV.There were no significant differences in HRV indices between the two groups at baseline. MCI subjects exhibited smaller physiological changes in all three HRV indices during active standing, consistently with a dysfunction of the orthosympathetic system. Systolic BP after 10 minutes of standing was lower in MCI subjects, suggesting dysautonomia-related orthostatic BP dysregulation.Our study is novel in providing evidence of autonomic dysfunction in MCI. This is associated with orthostatic BP dysregulation and the ongoing follow-up of the study population will
Alvarez-Ramirez, J.; Echeverria, J. C.; Meraz, M.; Rodriguez, E.
The heart rate variability (HRV) is an important physiological signal used either to assess the risk of cardiac death or to model the cardiovascular regulatory dynamics. Asymmetries in HRV data have been observed using 2D Poincare plots, which have been linked to a non-equilibrium operation of the cardiac autonomic system. This work further explores the presence of asymmetries but in the serial correlations of the dynamics of HRV data. To this end, detrended fluctuation analysis (DFA) was used to estimate the Hurst exponent both when the heart rate is accelerating and when it is decelerating. The analysis is conducted using data collected from subjects under normal sinus rhythm (NSR), congestive heart failure (CHF) and atrial fibrillation (AF) . For the NSR cases, it was found that correlations are stronger (p behavior was detected for the CHF and AF patients. Possible links between asymmetric correlations in the dynamics and the mechanisms controlling the operation of the heart rate are discussed, as well as their implications for modeling the cardiovascular regulatory dynamics.
Hoh, Jeong Kyu; Park, Young-Sun; Cha, Kyung-Joon; Park, Moon-Il
To define reference ranges for fetal heart rate (FHR) parameters after vibroacoustic stimulation (VAS) according to gestational age by determining the relationship between FHR and gestational age using a computerized analysis system. Data were analyzed from 3453 women using 10-minute observational recordings during nonstress testing (NST) and VAS testing. FHR parameters were analyzed according to gestational age. All FHR parameters were related to gestational age except for mean baseline FHR, which did not vary significantly with gestational age. All other parameters followed trends similar to the NST results, except for decelerations. FHR parameters after VAS differed significantly according to gestational age. The results suggest that the gestational age of the fetus should be considered when interpreting FHR patterns after VAS.
David C. Randall
Full Text Available We recorded via telemetry the arterial blood pressure (BP and heart rate (HR response to classical conditioning following the spontaneous onset of autoimmune diabetes in BBDP/Wor rats versus age-matched, diabetes resistant control (BBDR/Wor rats. Our purpose was to evaluate the autonomic regulatory responses to an acute stress in a diabetic state of up to 12 months duration. The stress was a 15 sec. pulsed tone (CS+ followed by a 0.5 sec. tail shock. The initial, transient increase in BP (i.e., the ‘first component’, or C1, known to be derived from an orienting response and produced by a sympathetic increase in peripheral resistance, was similar in diabetic and control rats through ~9 months of diabetes; it was smaller in diabetic rats 10 months after diabetes onset. Weakening of the C1 BP increase in rats that were diabetic for > 10 months is consistent with the effects of sympathetic neuropathy. A longer-latency, smaller, but sustained ‘second component’ (C2 conditional increase in BP, that is acquired as a rat learns the association between CS+ and the shock, and which results from an increase in cardiac output, was smaller in the diabetic vs. control rats starting from the first month of diabetes. A concomitant HR slowing was also smaller in diabetic rats. The difference in the C2 BP increase, as observed already during the first month of diabetes, is probably secondary to the effects of hyperglycemia upon myocardial metabolism and contractile function, but it may also result from effects on cognition. The small HR slowing concomitant with the C2 pressor event is probably secondary to differences in baroreflex activation or function, though parasympathetic dysfunction may contribute later in the duration of diabetes. The nearly immediate deficit after disease onset in the C2 response indicates that diabetes alters BP and HR responses to external challenges prior to the development of structural changes in the vasculature or autonomic
Monfredi, Oliver; Lyashkov, Alexey E; Johnsen, Anne-Berit; Inada, Shin; Schneider, Heiko; Wang, Ruoxi; Nirmalan, Mahesh; Wisloff, Ulrik; Maltsev, Victor A; Lakatta, Edward G; Zhang, Henggui; Boyett, Mark R
Heart rate (HR) variability (HRV; beat-to-beat changes in the R-wave to R-wave interval) has attracted considerable attention during the past 30+ years (PubMed currently lists >17 000 publications). Clinically, a decrease in HRV is correlated to higher morbidity and mortality in diverse conditions, from heart disease to fetal distress. It is usually attributed to fluctuation in cardiac autonomic nerve activity. We calculated HRV parameters from a variety of cardiac preparations (including humans, living animals, Langendorff-perfused heart, and single sinoatrial nodal cell) in diverse species, combining this with data from previously published articles. We show that regardless of conditions, there is a universal exponential decay-like relationship between HRV and HR. Using 2 biophysical models, we develop a theory for this and confirm that HRV is primarily dependent on HR and cannot be used in any simple way to assess autonomic nerve activity to the heart. We suggest that the correlation between a change in HRV and altered morbidity and mortality is substantially attributable to the concurrent change in HR. This calls for re-evaluation of the findings from many articles that have not adjusted properly or at all for HR differences when comparing HRV in multiple circumstances. © 2014 American Heart Association, Inc.
Arslan, Ugur; Ozdemir, Murat; Kocaman, Sinan Altan; Balcioglu, Serhat; Cemri, Mustafa; Cengel, Atiye
To study heart rate (HR) variability and HR turbulence parameters in mild-to-moderate aortic stenosis (AS) and to disclose whether any relationship exists between these parameters and echocardiographic findings. Forty-three asymptomatic patients with mild-to-moderate AS (AS group) were studied. Echocardiographic parameters and HR variability and HR turbulence indices obtained over 24 Holter ECG recordings were compared with those of an age and sex matched control population free of cardiovascular disease. Correlation between echocardiographic findings and HR variability and HR turbulence indices was also studied in the AS group. All HR variability parameters except mean RR interval, RMSSD, and pNN50 and one HR turbulence parameter, turbulence onset, were significantly disturbed in the AS group. Echocardiographic findings of diastolic dysfunction had significant correlations with HR variability and HR turbulence parameters in AS patients. Symphatovagal imbalance as shown by disturbed HR variability and HR turbulence parameters was demonstrated for the first time in patients with mild-to-moderate AS. This imbalance, which was shown to be correlated with echocardiographic findings of diastolic dysfunction, may lead to arrhythmic complications in this seemingly low-risk patient population.
Paul M Macey
Full Text Available Obstructive sleep apnea (OSA is accompanied by structural alterations and dysfunction in central autonomic regulatory regions, which may impair dynamic and static cardiovascular regulation, and contribute to other syndrome pathologies. Characterizing cardiovascular responses to autonomic challenges may provide insights into central nervous system impairments, including contributions by sex, since structural alterations are enhanced in OSA females over males. The objective was to assess heart rate responses in OSA versus healthy control subjects to autonomic challenges, and, separately, characterize female and male patterns. We studied 94 subjects, including 37 newly-diagnosed, untreated OSA patients (6 female, age mean ± std: 52.1 ± 8.1 years; 31 male aged 54.3 ± 8.4 years, and 57 healthy control subjects (20 female, 50.5 ± 8.1 years; 37 male, 45.6 ± 9.2 years. We measured instantaneous heart rate with pulse oximetry during cold pressor, hand grip, and Valsalva maneuver challenges. All challenges elicited significant heart rate differences between OSA and control groups during and after challenges (repeated measures ANOVA, p<0.05. In post-hoc analyses, OSA females showed greater impairments than OSA males, which included: for cold pressor, lower initial increase (OSA vs. control: 9.5 vs. 7.3 bpm in females, 7.6 vs. 3.7 bpm in males, OSA delay to initial peak (2.5 s females/0.9 s males, slower mid-challenge rate-of-increase (OSA vs. control: -0.11 vs. 0.09 bpm/s in females, 0.03 vs. 0.06 bpm/s in males; for hand grip, lower initial peak (OSA vs. control: 2.6 vs. 4.6 bpm in females, 5.3 vs. 6.0 bpm in males; for Valsalva maneuver, lower Valsalva ratio (OSA vs. control: 1.14 vs. 1.30 in females, 1.29 vs. 1.34 in males, and OSA delay during phase II (0.68 s females/1.31 s males. Heart rate responses showed lower amplitude, delayed onset, and slower rate changes in OSA patients over healthy controls, and impairments may be more pronounced in
Full Text Available Biological organisms have intrinsic control systems that act in response to internal and external stimuli maintaining homeostasis. Human heart rate is not regular and varies in time and such variability, also known as heart rate variability (HRV, is not random. HRV depends upon organism's physiologic and/or pathologic state. Physicians are always interested in predicting patient's risk of developing major and life-threatening complications. Understanding biological signals behavior helps to characterize patient's state and might represent a step toward a better care. The main advantage of signals such as HRV indexes is that it can be calculated in real time in noninvasive manner, while all current biomarkers used in clinical practice are discrete and imply blood sample analysis. In this paper HRV linear and nonlinear indexes are reviewed and data from real patients are provided to show how these indexes might be used in clinical practice.
Santana, Milana Drumond Ramos; de Souza, Ana Cecilia Amorim; de Abreu, Luiz Carlos; Valenti, Vitor E
The heart rate variability is a useful method to assess cardiac autonomic modulation in patients undergoing dental procedures, because knowledge of physiological conditions provides greater security to the professional as well as the possibility of a better plan treatment to patient benefit. The aim of our study was to describe the association between cardiac autonomic control and dental variables. We consulted the databases Medline, SciELO, Lilacs and Cochrane, using the terms "autonomic", "dentistry", "heart rate variability", "cardiovascular physiology." The selected studies indicated a strong relationship between dental variables and HRV. There was an association between malocclusion, TMD, dental procedures cirugia and low HRV. Thus, they become more studies that relate to HRV in dental science, especially in clinical practice.
Oskari Kilpeläinen, Tuomas
Genome-wide association studies (GWASs) have revolutionized the search for genetic variants regulating resting heart rate. In the last 10 years, GWASs have led to the identification of at least 21 novel heart rate loci. These discoveries have provided valuable insights into the mechanisms...... and pathways that regulate heart rate and link heart rate to cardiovascular morbidity and mortality. GWASs capture majority of genetic variation in a population sample by utilizing high-throughput genotyping chips measuring genotypes for up to several millions of SNPs across the genome in thousands...... of individuals. This allows the identification of the strongest heart rate associated signals at genome-wide level. While GWASs provide robust statistical evidence of the association of a given genetic locus with heart rate, they are only the starting point for detailed follow-up studies to locate the causal...
Nanchen, David; Leening, Maarten J G; Locatelli, Isabella; Cornuz, Jacques; Kors, Jan A; Heeringa, Jan; Deckers, Jaap W; Hofman, Albert; Franco, Oscar H; Stricker, Bruno H Ch; Witteman, Jacqueline C M; Dehghan, Abbas
An elevated resting heart rate is associated with rehospitalization for heart failure and is a modifiable risk factor in heart failure patients. We aimed to examine the association between resting heart rate and incident heart failure in a population-based cohort study of healthy adults without pre-existing overt heart disease. We studied 4768 men and women aged ≥55 years from the population-based Rotterdam Study. We excluded participants with prevalent heart failure, coronary heart disease, pacemaker, atrial fibrillation, atrioventricular block, and those using β-blockers or calcium channel blockers. We used extended Cox models allowing for time-dependent variation of resting heart rate along follow-up. During a median of 14.6 years of follow-up, 656 participants developed heart failure. The risk of heart failure was higher in men with higher resting heart rate. For each increment of 10 beats per minute, the multivariable adjusted hazard ratios in men were 1.16 (95% confidence interval, 1.05-1.28; P=0.005) in the time-fixed heart rate model and 1.13 (95% confidence interval, 1.02-1.25; P=0.017) in the time-dependent heart rate model. The association could not be demonstrated in women (P for interaction=0.004). Censoring participants for incident coronary heart disease or using time-dependent models to account for the use of β-blockers or calcium channel blockers during follow-up did not alter the results. Baseline or persistent higher resting heart rate is an independent risk factor for the development of heart failure in healthy older men in the general population.
Hewett, Zoe L; Pumpa, Kate L; Smith, Caroline A; Fahey, Paul P; Cheema, Birinder S
Chronic activation of the stress-response can contribute to cardiovascular disease risk, particularly in sedentary individuals. This study investigated the effect of a Bikram yoga intervention on the high frequency power component of heart rate variability (HRV) and associated cardiovascular disease (CVD) risk factors (i.e. additional domains of HRV, hemodynamic, hematologic, anthropometric and body composition outcome measures) in stressed and sedentary adults. Eligible adults were randomized to an experimental group (n = 29) or a no treatment control group (n = 34). Experimental group participants were instructed to attend three to five supervised Bikram yoga classes per week for 16 weeks at local studios. Outcome measures were assessed at baseline (week 0) and completion (week 17). Sixty-three adults (37.2 ± 10.8 years, 79% women) were included in the intention-to-treat analysis. The experimental group attended 27 ± 18 classes. Analyses of covariance revealed no significant change in the high-frequency component of HRV (p = 0.912, partial η 2 = 0.000) or in any secondary outcome measure between groups over time. However, regression analyses revealed that higher attendance in the experimental group was associated with significant reductions in diastolic blood pressure (p = 0.039; partial η 2 = 0.154), body fat percentage (p = 0.001, partial η 2 = 0.379), fat mass (p = 0.003, partial η 2 = 0.294) and body mass index (p = 0.05, partial η 2 = 0.139). A 16-week Bikram yoga program did not increase the high frequency power component of HRV or any other CVD risk factors investigated. As revealed by post hoc analyses, low adherence likely contributed to the null effects. Future studies are required to address barriers to adherence to better elucidate the dose-response effects of Bikram yoga practice as a medium to lower stress-related CVD risk. Retrospectively registered with Australia New Zealand Clinical Trials Registry ACTRN
Soares-Caldeira, Lúcio F; de Souza, Eberton A; de Freitas, Victor H; de Moraes, Solange M F; Leicht, Anthony S; Nakamura, Fábio Y
The aim of this study was to investigate whether supplementing regular preseason futsal training with weekly sessions of repeated sprints (RS) training would have positive effects on repeated sprint ability (RSA) and field test performance. Thirteen players from a professional futsal team (22.6 ± 6.7 years, 72.8 ± 8.7 kg, 173.2 ± 6.2 cm) were divided randomly into 2 groups (AddT: n = 6 and normal training group: n = 7). Both groups performed a RSA test, Yo-Yo intermittent recovery test level 1 (YoYo IR1), squat (SJ) and countermovement jumps (CMJ), body composition, and heart rate variability (HRV) measures at rest before and after 4 weeks of preseason training. Athletes weekly stress symptoms were recorded by psychometric responses using the Daily Analysis of Life Demands for Athletes questionnaire and subjective ratings of well-being scale, respectively. The daily training load (arbitrary units) was assessed using the session of rating perceived exertion method. After the preseason training, there were no significant changes for body composition, SJ, CMJ, and RSAbest. The YoYo IR1, RSAmean, RSAworst, and RSAdecreament were significantly improved for both groups (p ≤ 0.05). The HRV parameters improved significantly within both groups (p ≤ 0.05) except for high frequency (HF, absolute and normalized units, [n.u.]), low frequency (LF) (n.u.), and the LF/HF ratio. A moderate effect size for the AddT group was observed for resting heart rate and several HRV measures. Training load and psychometric responses were similar between both groups. Additional RS training resulted in slightly greater positive changes for vagal-related HRV with similar improvements in performance and training stress during the preseason training in futsal players.
Boudoulas, Konstantinos Dean; Borer, Jeffrey S; Boudoulas, Harisios
It has long been known that life span is inversely related to resting heart rate in most organisms. This association between heart rate and survival has been attributed to the metabolic rate, which is greater in smaller animals and is directly associated with heart rate. Studies have shown that heart rate is related to survival in apparently healthy individuals and in patients with different underlying cardiovascular diseases. A decrease in heart rate due to therapeutic interventions may result in an increase in survival. However, there are many factors regulating heart rate, and it is quite plausible that these may independently affect life expectancy. Nonetheless, a fast heart rate itself affects the cardiovascular system in multiple ways (it increases ventricular work, myocardial oxygen consumption, endothelial stress, aortic/arterial stiffness, decreases myocardial oxygen supply, other) which, in turn, may affect survival. In this brief review, the effects of heart rate on the heart, arterial system and survival will be discussed. © 2015 S. Karger AG, Basel.
Coppetti, Thomas; Brauchlin, Andreas; Müggler, Simon; Attinger-Toller, Adrian; Templin, Christian; Schönrath, Felix; Hellermann, Jens; Lüscher, Thomas F; Biaggi, Patric; Wyss, Christophe A
Background Smartphone manufacturers offer mobile health monitoring technology to their customers, including apps using the built-in camera for heart rate assessment. This study aimed to test the diagnostic accuracy of such heart rate measuring apps in clinical practice. Methods The feasibility and accuracy of measuring heart rate was tested on four commercially available apps using both iPhone 4 and iPhone 5. 'Instant Heart Rate' (IHR) and 'Heart Fitness' (HF) work with contact photoplethysmography (contact of fingertip to built-in camera), while 'Whats My Heart Rate' (WMH) and 'Cardiio Version' (CAR) work with non-contact photoplethysmography. The measurements were compared to electrocardiogram and pulse oximetry-derived heart rate. Results Heart rate measurement using app-based photoplethysmography was performed on 108 randomly selected patients. The electrocardiogram-derived heart rate correlated well with pulse oximetry ( r = 0.92), IHR ( r = 0.83) and HF ( r = 0.96), but somewhat less with WMH ( r = 0.62) and CAR ( r = 0.60). The accuracy of app-measured heart rate as compared to electrocardiogram, reported as mean absolute error (in bpm ± standard error) was 2 ± 0.35 (pulse oximetry), 4.5 ± 1.1 (IHR), 2 ± 0.5 (HF), 7.1 ± 1.4 (WMH) and 8.1 ± 1.4 (CAR). Conclusions We found substantial performance differences between the four studied heart rate measuring apps. The two contact photoplethysmography-based apps had higher feasibility and better accuracy for heart rate measurement than the two non-contact photoplethysmography-based apps.
Lamberts, R.P.; Lemmink, K.A.P.M.; Durandt, J.J.; Lambert, M.I.
A change in heart rate at a controlled submaximal exercise intensity is used as a marker of training status. However, the standard error of measurement has not been studied systematically, and therefore a change in heart rate, which can be considered relevant, has not been determined. Forty-four
Zamuner, Antonio Roberto; Cunha, Andrea Baraldi; da Silva, Ester; Negri, Ana Paola; Tudella, Eloisa; Moreno, Marlene Aparecida
The study of heart rate variability is an important tool for a noninvasive evaluation of the neurocardiac integrity. The present study aims to evaluate the autonomic heart rate modulation in supine and standing positions in 12 children diagnosed with cerebral palsy and 16 children with typical motor development (control group), as well as to…
Notarius, Catherine F; Floras, John S
In chronic heart failure (CHF) due to left ventricular dysfunction, diminished heart rate variability (HRV) is an independent predictor of poor prognosis. Caffeine has been shown to increase HRV in young healthy subjects. Such an increase may be of potential benefit to patients with CHF. We hypothesized that intravenous infusion of caffeine would increase HRV in CHF, and in age-matched healthy control subjects. On two separate days, 11 patients (1F) with CHF (age=51.3±4.6 years; left ventricular ejection fraction=18.6±2.7%; mean±standard error) and 10 healthy control subjects (age=48.0±4.0) according to a double-blind randomization design, received either saline or caffeine (4 mg/kg) infusion. We assessed HRV over 7 minutes of supine rest (fast Fourier Transform analysis) to determine total spectral power as well as its high-frequency (HF) (0.15-0.50 Hz) and low-frequency (LF) (0.05-0.15 Hz) components, and recorded muscle sympathetic nerve activity (MSNA) directly from the peroneal nerve (microneurography). In healthy control subjects, compared with saline, caffeine reduced both heart rate and sympathetic nerve traffic (p≤0.003) and increased the ratio of HF/total power (p≤0.05). Baseline LF power and the ratio LF/HF were significantly lower in CHF compared with controls (p=0.02), but caffeine had no effect on any element of HRV. Caffeine increases cardiac vagal heart rate modulation and reduces MSNA in middle-aged healthy subjects, but not in those with CHF.
Kasermann Hans P
Full Text Available Abstract Background Pain of mild to moderate grade is difficult to detect in laboratory mice because mice are prey animals that attempt to elude predators or man by hiding signs of weakness, injury or pain. In this study, we investigated the use of telemetry to identify indicators of mild-to-moderate post-laparotomy pain. Results Adult mice were subjected to laparotomy, either combined with pain treatment (carprofen or flunixin, 5 mg/kg s/c bid, for 1 day or without pain relief. Controls received anesthesia and analgesics or vehicle only. Telemetrically measured locomotor activity was undisturbed in all animals, thus confirming that any pain experienced was of the intended mild level. No symptoms of pain were registered in any of the groups by scoring the animals' outer appearance or spontaneous and provoked behavior. In contrast, the group receiving no analgesic treatment after laparotomy demonstrated significant changes in telemetry electrocardiogram recordings: increased heart rate and decreased heart rate variability parameters pointed to sympathetic activation and pain lasting for 24 hours. In addition, core body temperature was elevated. Body weight and food intake were reduced for 3 and 2 days, respectively. Moreover, unstructured cage territory and destroyed nests appeared for 1–2 days in an increased number of animals in this group only. In controls these parameters were not affected. Conclusion In conclusion, real-time telemetric recordings of heart rate and heart rate variability were indicative of mild-to-moderate post-laparotomy pain and could define its duration in our mouse model. This level of pain cannot easily be detected by direct observation.
Arras, Margarete; Rettich, Andreas; Cinelli, Paolo; Kasermann, Hans P; Burki, Kurt
Background Pain of mild to moderate grade is difficult to detect in laboratory mice because mice are prey animals that attempt to elude predators or man by hiding signs of weakness, injury or pain. In this study, we investigated the use of telemetry to identify indicators of mild-to-moderate post-laparotomy pain. Results Adult mice were subjected to laparotomy, either combined with pain treatment (carprofen or flunixin, 5 mg/kg s/c bid, for 1 day) or without pain relief. Controls received anesthesia and analgesics or vehicle only. Telemetrically measured locomotor activity was undisturbed in all animals, thus confirming that any pain experienced was of the intended mild level. No symptoms of pain were registered in any of the groups by scoring the animals' outer appearance or spontaneous and provoked behavior. In contrast, the group receiving no analgesic treatment after laparotomy demonstrated significant changes in telemetry electrocardiogram recordings: increased heart rate and decreased heart rate variability parameters pointed to sympathetic activation and pain lasting for 24 hours. In addition, core body temperature was elevated. Body weight and food intake were reduced for 3 and 2 days, respectively. Moreover, unstructured cage territory and destroyed nests appeared for 1–2 days in an increased number of animals in this group only. In controls these parameters were not affected. Conclusion In conclusion, real-time telemetric recordings of heart rate and heart rate variability were indicative of mild-to-moderate post-laparotomy pain and could define its duration in our mouse model. This level of pain cannot easily be detected by direct observation. PMID:17683523
Full Text Available Background: To evaluate the changes in autonomic neural control mechanisms before malignant ventricular arrhythmias, we measured heart rate variability (HRV and heart rate turbulence (HRT in patients with ventricular tachycardia or fibrillation (Group I; n=6, non sustained ventricular tachycardia (Group II; n=32, frequent premature ventricular beats (Group III; n=26 and with ICD implantation (Group IV; n=11. Methods: Time domain parameters of HRV and turbulence onset (TO and slope (TS were calculated on 24 hour Holter recordings. Normal values were: SDNN > 70 msec for HRV, TO <0% and TS >2.5 msec/RR-I for HRT. Results: Whereas SDNN was within normal range and similar in all study groups, HRT parameters were significantly different in patients who experienced VT/VF during Holter recording. Abnormal TO and/or TS were present in 100% of Group I patients and only in about 50% of Group II and IV. On the contrary, normal HRT parameters were present in 40-70% of Group II, III and IV patients and none of Group I. Conclusions: These data suggest that HRT analysis is more suitable than HRV to detect those transient alterations in autonomic control mechanisms that are likely to play a major trigger role in the genesis of malignant cardiac arrhythmias. (Heart International 2007; 3: 51-7
Lauzier, Benjamin; Vaillant, Fanny; Gélinas, Roselle; Bouchard, Bertrand; Brownsey, Roger; Thorin, Eric; Tardif, Jean-Claude; Des Rosiers, Christine
Heart rate reduction (HRR) is an important target in the management of patients with chronic stable angina. Most available drugs for HRR, such as β-blockers, have adverse effects, including on cardiac energy substrate metabolism, a well-recognized determinant of cardiac homeostasis. This study aimed at 1) testing whether HRR by ivabradine (IVA) alters substrate metabolism in the healthy normoxic working heart and 2) comparing the effect of IVA with that of the β-blocker metoprolol (METO). This was assessed using our well-established model of ex vivo mouse heart perfusion in the working mode, which enables concomitant evaluation of myocardial contractility and metabolic fluxes using (13)C-labeled substrates. Hearts were perfused in the absence (controls; n = 10) or presence of IVA (n = 10, 3 μM) with or without atrial pacing to abolish HRR in the IVA group. IVA significantly reduced HR (35 ± 5%) and increased stroke volume (39 ± 9%) while maintaining similar cardiac output, contractility, power, and efficiency. Effects of IVA on HR and stroke volume were reversed by atrial pacing. At the metabolic level, IVA did not impact on substrate selection to citrate formation, rates of glycolysis, or tissue levels of high-energy phosphates. In contrast, METO, at concentrations up to 40 μM, decreased markedly cardiac function (flow: 25 ± 6%; stroke volume: 30 ± 10%; contractility: 31 ± 9%) as well as glycolysis (2.9-fold) but marginally affected HR. Collectively, these results demonstrate that IVA selectively reduces HR while preserving energy substrate metabolism of normoxic healthy working mouse hearts perfused ex vivo, a model that mimics to some extent the denervated transplanted heart. Our results provide the impetus for testing selective HRR by IVA on cardiac substrate metabolism in pathological models.
Schreurs, Bernard G; Smith-Bell, Carrie A; Darwish, Deya S; Wang, Desheng; Burhans, Lauren B; Gonzales-Joekes, Jimena; Deci, Stephen; Stankovic, Goran; Sparks, D Larry
The cholesterol-fed rabbit is a model of atherosclerosis and has been proposed as an animal model of Alzheimer's disease. Feeding rabbits cholesterol has been shown to increase the number of beta amyloid immunoreactive neurons in the cortex. Addition of copper to the drinking water of cholesterol-fed rabbits can increase this number still further and may lead to plaque-like structures. Classical conditioning of the nictitating membrane response in cholesterol-fed rabbits is retarded in the presence of these plaque-like structures but may be facilitated in their absence. In a factorial design, rabbits fed 2% cholesterol or a normal diet (0% cholesterol) for 8 weeks with or without copper added to the drinking water were given trace classical conditioning using a tone and periorbital electrodermal stimulation to study the effects of cholesterol and copper on classical conditioning of heart rate and the nictitating membrane response. Cholesterol-fed rabbits showed significant facilitation of heart rate conditioning and conditioning-specific modification of heart rate relative to normal diet controls. Consistent with previous research, cholesterol had minimal effects on classical conditioning of the nictitating membrane response when periorbital electrodermal stimulation was used as the unconditioned stimulus. Immunohistochemical analysis showed a significant increase in the number of beta amyloid positive neurons in the cortex, hippocampus and amygdala of the cholesterol-fed rabbits. Supplementation of drinking water with copper increased the number of beta amyloid positive neurons in the cortex of cholesterol-fed rabbits but did not produce plaque-like structures or have a significant effect on heart rate conditioning. The data provide additional support for our finding that, in the absence of plaques, dietary cholesterol may facilitate learning and memory.
Tofler, Geoffrey H; Massaro, Joseph; Levy, Daniel A; Sutherland, Patrice A; Buckley, Thomas; D'Agostino, Ralph B
Background Although a higher heart rate is associated with an increased risk of cardiovascular disease, the mechanism is not well understood. As thrombosis has an important role in plaque development and acute coronary syndromes, the increase related to heart rate may result from a prothrombotic imbalance. Methods We investigated the relation between heart rate and thrombotic potential in 3451 participants from the Offspring Cohort of the Framingham Heart Study (mean age 54 years, 55% women). Participants were divided into quintiles based on heart rate derived from a resting electrocardiogram. Results Higher heart rates were associated with significant age-adjusted increases in fibrinogen, viscosity, factor VII antigen, and impaired fibrinolytic potential (plasminogen activator inhibitor and tissue plasminogen activator antigen) among men and women, and von Willebrand factor antigen among men. Fibrinogen levels were 9% higher among men with a heart rate of 80.9 ± 8.1 beats/min (quintile 5) vs. 50.0 ± 3.9 beats/min (quintile 1) (314 vs. 287 mg/dl, p heart rates are associated with a prothrombotic state. Because these factors are also associated with endothelial dysfunction and inflammation, these findings are consistent with an injurious effect of higher heart rates on the endothelium. Measures to reduce thrombotic potential may be of particular value in people with higher heart rates.
de Morais, Sharon Del Bem Velloso; da Silva, Luiz Eduardo Virgilio; Lataro, Renata Maria; Silva, Carlos Alberto Aguiar; de Oliveira, Luciano Fonseca Lemos; de Carvalho, Eduardo Elias Vieira; Simões, Marcus Vinicius; da Silva Meirelles, Lindolfo; Fazan, Rubens
Heart failure induced by myocardial infarct (MI) attenuates the heart rate variability (HRV) and baroreflex sensitivity, which are important risk factors for life-threatening cardiovascular events. Therapies with mesenchymal stem cells (MSCs) have shown promising results after MI. However, the effects of MSCs on hemodynamic (heart rate and arterial pressure) variability and baroreflex sensitivity in chronic heart failure (CHF) following MI have not been evaluated thus far. Male Wistar rats received MSCs or saline solution intravenously 1 week after ligation of the left coronary artery. Control (noninfarcted) rats were also evaluated. MI size was assessed using single-photon emission computed tomography (SPECT). The left ventricular ejection fraction (LVEF) was evaluated using radionuclide ventriculography. Four weeks after MSC injection, the animals were anesthetized and instrumented for chronic ECG recording and catheters were implanted in the femoral artery to record arterial pressure. Arterial pressure and HRVs were determined in time and frequency domain (spectral analysis) while HRV was also examined using nonlinear methods: DFA (detrended fluctuation analysis) and sample entropy. The initial MI size was the same among all infarcted rats but was reduced by MSCs. CHF rats exhibited increased myocardial interstitial collagen and sample entropy combined with the attenuation of the following cardiocirculatory parameters: DFA indices, LVEF, baroreflex sensitivity, and HRV. Nevertheless, MSCs hampered all these alterations, except the LVEF reduction. Therefore, 4 weeks after MSC therapy was applied to CHF rats, MI size and myocardial interstitial fibrosis decreased, while baroreflex sensitivity and HRV improved. PMID:26059001
Miriam R. Waldeck
Full Text Available Resting heart rate has sometimes been used as a marker of training status. It is reasonable to assume that the relationship between heart rate and training status should be more evident during sleep when extraneous factors that may influence heart rate are reduced. Therefore the aim of the study was to assess the repeatability of monitoring heart rate during sleep when training status remained unchanged, to determine if this measurement had sufficient precision to be used as a marker of training status. The heart rate of ten female subjects was monitored for 24 hours on three occasions over three weeks whilst training status remained unchanged. Average, minimum and maximum heart rate during sleep was calculated. The average heart rate of the group during sleep was similar on each of the three tests (65 ± 9, 63 ± 6 and 67 ± 7 beats·min-1 respectively. The range in minimum heart rate variation during sleep for all subjects over the three testing sessions was from 0 to 10 beats·min-1 (mean = 5 ± 3 beats·min-1 and for maximum heart rate variation was 2 to 31 beats·min-1 (mean = 13 ± 9 beats·min-1. In summary it was found that on an individual basis the minimum heart rate during sleep varied by about 8 beats·min-1. This amount of intrinsic day-to-day variation needs to be considered when changes in heart rate that may occur with changes in training status are interpreted
Waldeck, Miriam R; Lambert, Michael I
Resting heart rate has sometimes been used as a marker of training status. It is reasonable to assume that the relationship between heart rate and training status should be more evident during sleep when extraneous factors that may influence heart rate are reduced. Therefore the aim of the study was to assess the repeatability of monitoring heart rate during sleep when training status remained unchanged, to determine if this measurement had sufficient precision to be used as a marker of training status. The heart rate of ten female subjects was monitored for 24 hours on three occasions over three weeks whilst training status remained unchanged. Average, minimum and maximum heart rate during sleep was calculated. The average heart rate of the group during sleep was similar on each of the three tests (65 ± 9, 63 ± 6 and 67 ± 7 beats·min(-1) respectively). The range in minimum heart rate variation during sleep for all subjects over the three testing sessions was from 0 to 10 beats·min(-1) (mean = 5 ± 3 beats·min(-1)) and for maximum heart rate variation was 2 to 31 beats·min(-1) (mean = 13 ± 9 beats·min(-1)). In summary it was found that on an individual basis the minimum heart rate during sleep varied by about 8 beats·min(-1). This amount of intrinsic day-to-day variation needs to be considered when changes in heart rate that may occur with changes in training status are interpreted.
Gao, Zhan; Singh, Madhu V; Hall, Duane D; Koval, Olha M.; Luczak, Elizabeth D.; Joiner, Mei-ling A.; Chen, Biyi; Wu, Yuejin; Chaudhary, Ashok K; Martins, James B; Hund, Thomas J; Mohler, Peter J; Song, Long-Sheng; Anderson, Mark E.
Background Catecholamines increase heart rate by augmenting the cAMP responsive HCN4 ‘pacemaker current’ (If) and/or by promoting inward Na+/Ca2+ exchanger current (INCX), by a ‘Ca2+ clock’ mechanism in sinoatrial nodal cells (SANCs). The importance, identity and function of signals that connect If and Ca2+ clock mechanisms are uncertain and controversial, but the multifunctional Ca2+ and calmodulin-dependent protein kinase II (CaMKII) is required for physiological heart rate responses to β-adrenergic receptor (β-AR) stimulation. The aim of this stuy is to measure the contribution of the Ca2+ clock and CaMKII to cardiac pacing independent of β-AR agonist stimulation. Methods and Results We used the L-type Ca2+ channel agonist BayK 8644 (BayK) to activate the SANC Ca2+ clock. BayK and isoproterenol were similarly effective in increasing rates in SANCs and Langendorff-perfused hearts from WT control mice. In contrast, SANCs and isolated hearts from mice with CaMKII inhibition by transgenic expression of an inhibitory peptide (AC3-I) were resistant to rate increases by BayK. BayK only activated CaMKII in control SANCs, but increased ICa equally in all SANCs, indicating that increasing ICa was insufficient and suggesting CaMKII activation was required for heart rate increases by BayK. BayK did not increase If or protein kinase A (PKA)-dependent phosphorylation of phospholamban (at Ser16), indicating that increased SANC Ca2+ by BayK did not augment cAMP/PKA signaling at these targets. Late diastolic intracellular Ca2+ release and INCX were significantly reduced in AC3-I SANCs and the response to BayK was eliminated by ryanodine in all groups. Conclusions The Ca2+ clock is capable of supporting physiological fight or flight responses, independent of β-AR stimulation or If increases. Complete Ca2+ clock and β-AR stimulation responses require CaMKII. PMID:21406683
Thakre, Tushar P; Smith, Michael L
Background Heart rate variability (HRV) is known to be impaired in patients with congestive heart failure (CHF). Time-domain analysis of ECG signals traditionally relies heavily on linear indices of an essentially non-linear phenomenon. Poincaré plots are commonly used to study non-linear behavior of physiologic signals. Lagged Poincaré plots incorporate autocovariance information and analysis of Poincaré plots for various lags can provide interesting insights into the autonomic control of the heart. Methods Using Poincaré plot analysis, we assessed whether the relation of the lag between heart beats and HRV is altered in CHF. We studied the influence of lag on estimates of Poincaré plot indices for various lengths of beat sequence in a public domain data set (PhysioNet) of 29 subjects with CHF and 54 subjects with normal sinus rhythm. Results A curvilinear association was observed between lag and Poincaré plot indices (SD1, SD2, SDLD and SD1/SD2 ratio) in normal subjects even for a small sequence of 50 beats (p value for quadratic term 3 × 10-5, 0.002, 3.5 × 10-5 and 0.0003, respectively). This curvilinearity was lost in patients with CHF even after exploring sequences up to 50,000 beats (p values for quadratic term > 0.5). Conclusion Since lagged Poincaré plots incorporate autocovariance information, these analyses provide insights into the autonomic control of heart rate that is influenced by the non-linearity of the signal. The differences in lag-response in CHF patients and normal subjects exist even in the face of the treatment received by the CHF patients. PMID:16768800
Smith Michael L
Full Text Available Abstract Background Heart rate variability (HRV is known to be impaired in patients with congestive heart failure (CHF. Time-domain analysis of ECG signals traditionally relies heavily on linear indices of an essentially non-linear phenomenon. Poincaré plots are commonly used to study non-linear behavior of physiologic signals. Lagged Poincaré plots incorporate autocovariance information and analysis of Poincaré plots for various lags can provide interesting insights into the autonomic control of the heart. Methods Using Poincaré plot analysis, we assessed whether the relation of the lag between heart beats and HRV is altered in CHF. We studied the influence of lag on estimates of Poincaré plot indices for various lengths of beat sequence in a public domain data set (PhysioNet of 29 subjects with CHF and 54 subjects with normal sinus rhythm. Results A curvilinear association was observed between lag and Poincaré plot indices (SD1, SD2, SDLD and SD1/SD2 ratio in normal subjects even for a small sequence of 50 beats (p value for quadratic term 3 × 10-5, 0.002, 3.5 × 10-5 and 0.0003, respectively. This curvilinearity was lost in patients with CHF even after exploring sequences up to 50,000 beats (p values for quadratic term > 0.5. Conclusion Since lagged Poincaré plots incorporate autocovariance information, these analyses provide insights into the autonomic control of heart rate that is influenced by the non-linearity of the signal. The differences in lag-response in CHF patients and normal subjects exist even in the face of the treatment received by the CHF patients.
Osadchii, Oleg E
In the clinical setting, patients with slower resting heart rate are less prone to cardiovascular death compared with those with elevated heart rate. However, electrophysiological adaptations associated with reduced cardiac rhythm have not been thoroughly explored. In this study, relationships between intrinsic heart rate and arrhythmic susceptibility were examined by assessments of action potential duration (APD) rate adaptation and inducibility of repolarization alternans in sinoatrial node (SAN)-driven and atrioventricular (AV)-blocked guinea-pig hearts perfused with Langendorff apparatus. Electrocardiograms, epicardial monophasic action potentials, and effective refractory periods (ERP) were assessed in normokalemic and hypokalemic conditions. Slower basal heart rate in AV-blocked hearts was associated with prolonged ventricular repolarization during spontaneous beating, and with attenuated APD shortening at increased cardiac activation rates during dynamic pacing, when compared with SAN-driven hearts. During hypokalemic perfusion, the inducibility of repolarization alternans and tachyarrhythmia by rapid pacing was found to be lower in AV-blocked hearts. This difference was ascribed to prolonged ERP in the setting of reduced basal heart rate, which prevented ventricular capture at critically short pacing intervals required to induce arrhythmia. Reduced basal heart rate is associated with electrophysiological changes that prevent electrical instability upon an abrupt cardiac acceleration.
Hemmingsen, Jette Gjerke; Rissler, Jenny; Lykkesfeldt, Jens
BACKGROUND: Exposure to particulate matter (PM) is generally associated with elevated risk of cardiovascular morbidity and mortality. Elderly and obese subjects may be particularly susceptible, although short-term effects are poorly described. METHODS: Sixty healthy subjects (25 males, 35 females......, age 55 to 83 years, body mass index > 25 kg/m(2)) were included in a cross-over study with 5 hours of exposure to particle- or sham-filtered air from a busy street using an exposure-chamber. The sham- versus particle-filtered air had average particle number concentrations of ~23.000 versus ~1800/cm(3......) and PM2.5 levels of 24 versus 3μg/m(3), respectively. The PM contained similar fractions of elemental and black carbon (~20-25%) in both exposure scenarios. Reactive hyperemia and nitroglycerin-induced vasodilation in finger arteries and heart rate variability (HRV) measured within 1 h after exposure...
Lamberts, Robert P; Lemmink, Koen A P M; Durandt, Justin J; Lambert, Michael I
A change in heart rate at a controlled submaximal exercise intensity is used as a marker of training status. However, the standard error of measurement has not been studied systematically, and therefore a change in heart rate, which can be considered relevant, has not been determined. Forty-four subjects (26.5 +/- 5.4 years; mean +/- standard deviation) participated in a submaximal running test at the same time of day for 5 consecutive days. Heart rates were determined during each of the 4 exercise intensities (2 minutes each) of increasing intensity and during the 1-minute recovery period after each stage. The repeatability of the heart rate on a day-to-day basis during the stages and recovery periods were high (intraclass correlation coefficient: 95% confidence interval R = 0.94- 0.99). The lowest variation in heart rate occurred in the fourth stage ( approximately 90% maximum heart rate) with heart rate varying 5 +/- 2 b.min(-1) (95% confidence interval for coefficient of variation = 1.1-1.4%). In conclusion, the standard error of measurement of submaximal heart rate is 1.1-1.4%. This magnitude of measurement error needs to be considered when heart rate is used as a marker of training status.
Wong, Jih-Sen; Lu, Wan-An; Wu, Kung-Tai; Liu, Margaret; Chen, Gau-Yang; Kuo, Cheng-Deng
Both heart rate variability (HRV) and pulse rate variability (PRV) are noninvasive means for the assessment of autonomic nervous control of the heart. However, it is not settled whether or not the PRV obtained from either hand can be the surrogate of HRV. The HRV measures obtained from electrocardiographic signals and the PRV measures obtained from the pulse waves recorded from the index fingers of both hands were compared in normal subjects by using linear regression analysis and Bland and Altman method. Highly significant correlations (P heart rate and ultra-low frequency power (ULFP). The PRV of either hand is close to, but not the same as the HRV in healthy subjects. The HRV, right PRV and left PRV are not surrogates of one another in normal subjects except heart rate and ULFP. Since HRV is generally accepted as the standard method for the assessment of the autonomic nervous modulation of a subject, the PRV of either hand may not be suitable for the assessment of the cardiac autonomic nervous modulation of the subject.
B. Dierckx (Bram); J.H.M. Tulen (Joke); M.P. Lambregtse-van den Berg (Mijke); A. Tharner (Anne); V.W.V. Jaddoe (Vincent); H.A. Moll (Henriëtte); A. Hofman (Albert); F.C. Verhulst (Frank); H.W. Tiemeier (Henning)
textabstractAbstract OBJECTIVE: To assess the determinants of heart rate (HR) and heart rate variability (HRV) in children. The autonomic nervous system as measured by HR and HRV is considered a biological marker of psychopathology in children. METHODS: We examined the relationship of maternal
van Andel, Judith; Ungureanu, Constantin; Aarts, Ronald; Leijten, Frans; Arends, Johan
Heart rate is a useful neurophysiological sign when monitoring seizures in patients with epilepsy. In an ambulatory setting, heart rate is measured with ECG involving electrodes on the skin. This method is uncomfortable which is burdensome for patients and is sensitive to motion artifacts, which
Objectives. To deternrine the relationship between Umbilical arterial catecholamine levels and fetal heart rate variability and meconium passage. Study design. A prospective descriptive study was perfonned. Umbilical artery catecholamine levels were measured in 55 newborns and correlated with fetal heart rate before ...
A total of 400 apparently healthy pregnant women with singleton fetuses from Enugu, Southeast Nigeria were randomly selected for the study. The aims of the study are to establish: a normogram for fetal heart rate (FHR) and the relationship between fetal heart rate and gestational age (GA) by 2–D ultrasound. Crown rump ...
Background: Heart Rate Variability (HRV) describes the variations of both instantaneous heart rate and R-R intervals in an electrocardiogram. Low HRV is considered to be a non-invasive measurement of autonomic inactivity and propensity lethal arrhythmias. Methodology: This was a retrospective study of patients with ...
The effect of malaria on blood pressure, heart rate, electrocardiogram and the cardiovascular responses to postural change were studied in malaria patients. Blood pressure was measured by the sphygmomanometric-auscultatory method. Standard ECG machine was used to record the electrocardiogram. Heart rate was ...
Faye, Papa M; De Jonckheere, Julien; Logier, Regis; Kuissi, Eliane; Jeanne, Mathieu; Rakza, Thameur; Storme, Laurent
Systems controlling cardiovascular function are closely coupled with the perception of pain. Heart rate variability (HRV) is a well-established noninvasive measure of cardiac autonomic control. We hypothesized that pain may alter HRV in the newborn infant and that HRV analysis could be used as an indicator of prolonged pain in the newborn infant. To test the hypothesis, we measured the magnitude of the heart rate high-frequency variations using an innovative High Frequency Variability Index (HFVI) in newborn infants at risk of postoperative pain. We investigated newborn infants with a gestational age (GA) more than 34 weeks, and who were admitted after a major surgical procedure. Inclusions ranged from 2 to 72 hours after the surgery. The postoperative pain was scored using EDIN scale (neonatal pain and discomfort scale) at the end of the 2 hours recording period. The infants were separated in: (1) Group "Low EDIN," when EDIN=5. Predictive positive and negative values of a threshold value of HFVI in assessing pain have been studied. Twenty-eight newborn infants were enrolled in the study (mean GA=37.8+/-1.5 wk) at a median delay between the surgery and the recording of 5 hours. Mean EDIN were 2+/-1 and 7+/-2 in respectively the groups "Low EDIN" and "High EDIN." The 2 groups were similar for GA, basal heart and respiratory rates, SpO2, mean arterial blood pressure, and morphine infusion rate. HFVI was significantly lower in the group "High EDIN" than in the group "Low EDIN" (0.7+/-0.2 vs. 1.2+/-0.3, respectively; P=5, with a sensitivity of 90%, and a specificity of 75%. The results of this study indicate that postoperative pain is associated with a decreased high-frequency HRV in full-term newborn infants. Our findings suggest that HRV could be used as an indicator to assess prolonged pain in the newborn infants.
Hong Tang; Ting Li; Tianshuang Qiu; Yongwan Park
As a passive, harmless, and low-cost diagnosis tool, fetal heart rate (FHR) monitoring based on fetal phonocardiography (fPCG) signal is alternative to ultrasonographic cardiotocography. Previous fPCG-based methods commonly relied on the time difference of detected heart sound bursts. However, the performance is unavoidable to degrade due to missed heart sounds in very low signal-to-noise ratio environments. This paper proposes a FHR monitoring method using repetition frequency of heart sound...
Corino, Valentina D A; Cygankiewicz, Iwona; Mainardi, Luca T; Stridh, Martin; Vasquez, Rafael; Bayes de Luna, Antonio; Holmqvist, Fredrik; Zareba, Wojciech; Platonov, Pyotr G
Even if atrial fibrillatory rate (AFR) has been related to clinical outcome in patients with atrial fibrillation (AF), its relation with ventricular response has not been deeply studied. The aim of this study was to investigate the relation between AFR and RR series variability in patients with AF. Twenty-minute electrocardiograms in orthogonal leads were processed to extract AFR, using spatiotemporal QRST cancellation and time frequency analysis, and RR series in 127 patients (age 69 ± 11 years) with congestive heart failure (NYHA II-III) enrolled in the MUSIC study (MUerte Subita en Insufficiencia Cardiaca). Heart rate variability and irregularity were assessed by time domain parameters and entropy-based indices, respectively and their correlation with AFR investigated. Variability measures seem not to be related to AFR, while irregularity measures do. A significant correlation between AFR and variability parameters of heart rate variability during AF was found only in patients not treated with antiarrhythmics drugs (correlation = 0.56 P < 0.05 for pNN50), while this correlation was lost in patients taking rate- or rhythm-control drugs. A significant positive correlation between AFR and indices of RR irregularity was found, showing that a higher AFR is related to a less organized RR series (correlation = 0.33 P < 0.05 for regularity index for all patients, correlation increased in subgroups of patients treated with the same drug). These results suggest that a higher AFR is associated with a higher degree of irregularity of ventricular response that is observed regardless of the use of rate-controlling drugs. ©2012, Wiley Periodicals, Inc.
Jeppe Hagstrup Christensen
Full Text Available Omega-3 polyunsaturated fatty acids (PUFA may modulate autonomic control of the heart because omega-3 PUFA is abundant in the brain and other nervous tissue as well as in cardiac tissue. This might partly explain why omega-3 PUFA offer some protection against sudden cardiac death (SCD. The autonomic nervous system is involved in the pathogenesis of SCD. Heart rate variability (HRV can be used as a non-invasive marker of cardiac autonomic control and a low HRV is a predictor for SCD and arrhythmic events. Studies on HRV and omega-3 PUFA have been performed in several populations such as patients with ischemic heart disease, patients with diabetes mellitus, patients with chronic renal failure, and in healthy subjects as well as in children.. The studies have demonstrated a positive association between cellular content of omega-3 PUFA and HRV and supplementation with omega-3 PUFA seems to increase HRV which could be a possible explanation for decreased risk of arrhythmic events and SCD sometimes observed after omega-3 PUFA supplementation. However, the results are not consistent and further research is needed
Buck, Marilyn M.
This guide discusses the assessment of heart rate and, in particular, the assessment of heart rate using a heart monitor. Part 1, "Foundation for the Use of Heart Rate," reviews literature about heart rate assessment and heart rate monitors, offering an overview of national guidelines for physical activity. It focuses on the importance…
Hoikkala, Hanna; Haapalahti, Petri; Viitasalo, Matti; Väänänen, Heikki; Sovijärvi, Anssi R A; Ylikorkala, Olavi; Mikkola, Tomi S
The aim of this study was to investigate whether cardiovascular autonomic reactivity and risk profile are associated with the frequency and severity of hot flashes in recently postmenopausal women. A total of 150 postmenopausal women with varying degrees of severity of hot flashes (none, mild, moderate, or severe) underwent 24-hour electrocardiographic recording. The function of the autonomic nervous system was assessed via heart rate variability in time and frequency domains. The effects of hot flashes on cardiac autonomic function were studied by assessing heart rate variability in the presence and absence of symptoms. There were no differences in mean heart rate, heart rate extremes, or total number of ectopic beats between women without and women with mild, moderate, or severe hot flashes. However, most women (14/17, 82%) with frequent ventricular ectopic beats and all women with ventricular runs belonged to the symptomatic groups. Although there were no differences in 24-hour or nighttime heart rate variability between the study groups, the very-low-frequency spectral component of heart rate variability increased by 72% (P hot flash period compared with the control period and was accompanied by an increase in heart rate (3%; P hot flashes in recently postmenopausal women. However, during a hot flash episode, there were signs of altered autonomic control of heart rate, which may be involved in the regulatory mechanisms of hot flashes.
Billman, George E
Heart rate variability (HRV), the beat-to-beat variation in either heart rate (HR) or heart period (R-R interval), has become a popular clinical and investigational tool to quantify cardiac autonomic regulation. However, it is not widely appreciated that, due to the inverse curvilinear relationship between HR and R-R interval, HR per se can profoundly influence HRV. It is, therefore, critical to correct HRV for the prevailing HR particularly, as HR changes in response to autonomic neural activation or inhibition. The present study evaluated the effects of HR on the HRV response to autonomic interventions that either increased (submaximal exercise, n = 25 or baroreceptor reflex activation, n = 20) or reduced (pharmacological blockade: β-adrenergic receptor, muscarinic receptor antagonists alone and in combination, n = 25, or bilateral cervical vagotomy, n = 9) autonomic neural activity in a canine model. Both total (RR interval standard deviation, RRSD) and the high frequency (HF) variability (HF, 0.24-1.04 Hz) were determined before and in response to an autonomic intervention. All interventions that reduced or abolished cardiac parasympathetic regulation provoked large reductions in HRV even after HR correction [division by mean RRsec or (mean RRsec)(2) for RRSD and HF, respectively] while interventions that reduced HR yielded mixed results. β-adrenergic receptor blockade reduced HRV (RRSD but not HF) while both RRSD and HF increased in response to increases in arterial blood (baroreceptor reflex activation) even after HR correction. These data suggest that the physiological basis for HRV is revealed after correction for prevailing HR and, further, that cardiac parasympathetic activity is responsible for a major portion of the HRV in the dog.
George E Billman
Full Text Available Heart rate variability (HRV, the beat-to-beat variation in either heart rate (HR or heart period (R-R interval, has become a popular clinical and investigational tool to quantify cardiac autonomic regulation. However, it is not widely appreciated that, due to the inverse curvilinear relationship between HR and R-R interval, HR per se can profoundly influence HRV. It is, therefore, critical to correct HRV for the prevailing HR particularly, as HR changes in response to autonomic neural activation or inhibition. The present study evaluated the effects of HR on the HRV response to autonomic interventions that either increased (submaximal exercise, n = 25 or baroreceptor reflex activation, n = 20 or reduced (pharmacological blockade: β-adrenergic receptor, muscarinic receptor antagonists alone and in combination, n = 25, or bilateral cervical vagotomy, n = 9 autonomic neural activity in a canine model. Both total (RR interval standard deviation, RRSD and the high frequency variability (HF, 0.2 to 1.04 Hz were determined before and in response to an autonomic intervention. All interventions that reduced or abolished cardiac parasympathetic regulation provoked large reductions in HRV even after HR correction [division by mean RRsec or (mean RRsec2 for RRSD and HF, respectively] while interventions that reduced HR yielded mixed results. β-adrenergic receptor blockade reduced HRV (RRSD but not HF while both RRSD and HF increased in response to increases in arterial blood (baroreceptor reflex activation even after HR correction. These data suggest that the physiological basis for HRV is revealed after correction for prevailing HR and, further, that cardiac parasympathetic activity is responsible for a major portion of the HRV in the dog.
Smith, Denise L; Haller, Jeannie M; Benedict, Ron; Moore-Merrell, Lori
The primary objective of this observational study was to document the heart rate (HR) responses of firefighters during incident rehabilitation following firefighting activity in a high-rise building with a simulated fire on the 10th floor. Additionally, the study investigated potential factors, including firefighting workload, ambient temperature, firefighter movement, and individual characteristics, that may have affected HR during recovery. Firefighters (n = 198) were assigned to perform a simulation of fire suppression, search and rescue, or material support during one of six firefighting trials that involved different crew sizes and ascent modes, and were performed in different environmental conditions. After completing the simulated firefighting activity, firefighters reported to a rehabilitation area on the 8th floor. The rehabilitation area was staffed by firefighter/paramedics. HR was monitored continuously during simulated firefighting activity and a 15-minute rehabilitation period. Average HR during rehabilitation (HRmean) was calculated and compared across trials. Simulated firefighting activity was performed in the summer in Virginia, USA, and ambient conditions varied among trials (mean ± SD: 31 ± 4°C; 46 ± 15% relative humidity; 32 ± 4°C heat index). Duration of simulated firefighting activity ranged from 12.0 to 20.3 minutes among trials (mean: 15.4 ± 5.2 minutes). Over all trials, mean peak HR during simulations was 173 ± 18 beats·min(-1). Mean HR over all trials at entry into rehabilitation was 149 ± 24 beats·min(-1). Following 15 minutes of recovery, mean HR over all trials was 126 ± 23 beats·min(-1). Exploratory analyses revealed that higher workload during firefighting (stair trials), higher ambient temperature (≥30°C), greater movement during rehabilitation (≥0.1 g-force), higher age (≥45 years), and higher BMI (≥30.0 kg·m(-2)) were associated with higher HR responses during rehabilitation. During complex emergency
Ho, Jennifer E.; Larson, Martin G.; Ghorbani, Anahita; Cheng, Susan; Coglianese, Erin E.; Vasan, Ramachandran S.; Wang, Thomas J.
Background Higher heart rate has been associated with an adverse prognosis, but most prior studies focused on individuals with known cardiovascular disease or examined a limited number of outcomes. We sought to examine the association of baseline heart rate with both fatal and nonfatal outcomes during 2 decades of follow‐up. Methods and Results Our study included 4058 Framingham Heart Study participants (mean age 55 years, 56% women). Cox models were performed with multivariable adjustment for clinical risk factors and physical activity. A total of 708 participants developed incident cardiovascular disease (303 heart failure, 343 coronary heart disease, and 216 stroke events), 48 received a permanent pacemaker, and 1186 died. Baseline heart rate was associated with incident cardiovascular disease (hazard ratio [HR] 1.15 per 1 SD [11 bpm] increase in heart rate, 95% CI 1.07 to 1.24, P=0.0002), particularly heart failure (HR 1.32, 95% CI 1.18 to 1.48, Pheart rate was also associated with higher all‐cause (HR 1.17, 95% CI 1.11 to 1.24, Pheart rate abated or increased. In contrast, individuals with a higher heart rate had a lower risk of requiring permanent pacemaker placement (HR 0.55, 95% CI 0.38 to 0.79, P=0.001). Conclusions Individuals with a higher heart rate are at elevated long‐term risk for cardiovascular events, in particular, heart failure, and all‐cause death. On the other hand, a higher heart rate is associated with a lower risk of future permanent pacemaker implantation. PMID:24811610
Full Text Available The present study investigated the effects of brief synthesized spoken words with emotional content on the ratings of emotions and heart rate responses. Twenty participants' heart rate functioning was measured while they listened to a set of emotionally negative, neutral, and positive words produced by speech synthesizers. At the end of the experiment, ratings of emotional experiences were also collected. The results showed that the ratings of the words were in accordance with their valence. Heart rate deceleration was significantly the strongest and most prolonged to the negative stimuli. The findings are the first suggesting that brief spoken emotionally toned words evoke a similar heart rate response pattern found earlier for more sustained emotional stimuli.
Carlson, Nicholas; Dixen, Ulrik; Marott, Jacob L
BACKGROUND: Elevated resting heart rate (RHR) is associated with cardiovascular mortality and morbidity. Assessment of heart rate (HR) from Holter recording may afford a more precise estimate of the effect of RHR on cardiovascular risk, as compared to casual RHR. Comparative analysis was carried ...
Visser, E.K.; Reenen, van C.G.; Werf, van der J.T.N.; Schilder, M.B.H.; Knaap, J.H.; Barneveld, A.; Blokhuis, H.J.
Forty-one Dutch Warmblood immature horses were used in a study to quantify temperamental traits on the basis of heart rate (HR) and heart rate variability (HRV) measures. Half of the horses received additional training from the age of 5 months onwards; the other half did not. Horses were tested at
Riese, H.; Doornen, L.J.P. van; Houtman, I.L.D.; Geus, E.J.C. de
Objective. This study examined the effects of exposure to job strain on independent predictors of cardiovascular disease (ambulatory blood pressure, heart rate, and heart rate variability). Methods. The participants comprised a homogeneous group of 159 healthy female nurses [mean age 35.9 (SD 8.5)
Aeschbacher, Stefanie; Schoen, Tobias; Dörig, Laura; Kreuzmann, Rahel; Neuhauser, Charlotte; Schmidt-Trucksäss, Arno; Probst-Hensch, Nicole M; Risch, Martin; Risch, Lorenz; Conen, David
Heart rate (HR), heart rate variability (HRV), and inflammation are all associated with cardiovascular morbidity and mortality. The aim of this study was to assess potential interrelationships between these parameters in a young and healthy population. Healthy individuals aged 25-41 years were included in a prospective population-based study. All participants underwent 24-h electrocardiography using a validated device. The standard deviation of all normal RR intervals (SDNN) was pre-defined as the main HRV outcome variable. High-sensitivity C-reactive protein (hs-CRP), total leukocyte (LC) count and LC subtypes were obtained from venous blood samples. A total of 2064 participants (47% men, 37 years) were included in this analysis. In multivariable linear regression analyses using SDNN as the outcome variable, β-coefficients (95% confidence intervals) per 1 standard deviation (SD) increase on the log-scale were -0.11 (-0.16; -0.07), p healthy adults, inflammatory parameters were strongly associated with increased HR and decreased HRV, suggesting an important interaction between inflammatory pathways and the autonomic nervous system. Key message Inflammatory biomarkers, such as high-sensitivity C-reactive protein and leukocyte cell count with its subtypes were inversely associated with HRV and positively associated with HR. Our findings suggest important interrelationships between inflammatory pathways and the ANS.
Voggt, A; Berger, M; Obermeier, M; Löw, A; Seemueller, F; Riedel, M; Moeller, H J; Zimmermann, R; Kirchberg, F; Von Schacky, C; Severus, E
Affective disorders are associated with an increased risk of cardiovascular disease, which, at least partly, appears to be independent of psychopharmacological treatments used to manage these disorders. Reduced heart rate variability (SDNN) and a low Omega-3 Index have been shown to be associated with increased risk for death after myocardial infarction. Therefore, we set out to investigate heart rate variability and the Omega-3 Index in euthymic patients with bipolar disorders. We assessed heart rate variability (SDNN) and the Omega-3 Index in 90 euthymic, mostly medicated patients with bipolar disorders (Bipolar-I, Bipolar-II) on stable psychotropic medication, free of significant medical comorbidity and in 62 healthy controls. Heart rate variability was measured from electrocardiography under a standardized 30 minutes resting state condition. Age, sex, BMI, smoking, alcohol consumption and caffeine consumption as potential confounders were also assessed. Heart rate variability (SDNN) was significantly lower in patients with bipolar disorders compared to healthy controls (35.4 msec versus 60.7 msec; Pbipolar disorders versus healthy controls) and age significantly predicted heart rate variability (SDNN). Heart rate variability (SDNN) may provide a useful tool to study the impact of interventions aimed at reducing the increased risk of cardiovascular disease in euthymic patients with bipolar disorders. The difference in SDNN between cases and controls cannot be explained by a difference in the Omega-3 Index. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
Comparison of the rhythm control treatment strategy versus the rate control strategy in patients with permanent or long-standing persistent atrial fibrillation and heart failure treated with cardiac resynchronization therapy - a pilot study of Cardiac Resynchronization in Atrial Fibrillation Trial (Pilot-CRAfT): study protocol for a randomized controlled trial.
Ciszewski, Jan; Maciag, Aleksander; Kowalik, Ilona; Syska, Pawel; Lewandowski, Michal; Farkowski, Michal M; Borowiec, Anna; Chwyczko, Tomasz; Pytkowski, Mariusz; Szwed, Hanna; Sterlinski, Maciej
The only subgroups of patients with heart failure and atrial fibrillation in which the efficacy of cardiac resynchronization therapy has been scientifically proven are patients with indications for right ventricular pacing and patients after atrioventricular junction ablation. However it is unlikely that atrioventricular junction ablation would be a standard procedure in the majority of the heart failure patients with cardiac resynchronization therapy and concomitant atrial fibrillation due to the irreversible character of the procedure and a spontaneous sinus rhythm resumption that occurs in about 10% of these patients. Pilot-CRAfT is the first randomized controlled trial evaluating the efficacy of a rhythm control strategy in atrial fibrillation patients with cardiac resynchronization therapy devices. The aim of this prospective, single center randomized controlled pilot study is to answer the question whether the patients with cardiac resynchronization therapy and permanent atrial fibrillation would benefit from a strategy to restore and maintain sinus rhythm (that is 'rhythm control' strategy) in comparison to rate control strategy. The study population consists of 60 patients with heart failure and concomitant long-standing persistent or permanent atrial fibrillation who underwent a cardiac resynchronization therapy device implantation at least 3 months before qualification. Study participants are randomly assigned to the rhythm control strategy (including electrical cardioversion and pharmacotherapy) or to the rate control group whose goal is to control ventricular rate. The follow-up time is 12 months. The primary endpoint is the ratio of effectively captured biventricular beats. The secondary endpoints include peak oxygen consumption, six-minute walk test distance, heart failure symptom escalation, reverse remodelling of the heart on echo and quality of life. NCT01850277 registered on 22 April 2013 (ClinicalTrials.gov).
Lamberts, R P; Maskell, S; Borresen, J; Lambert, M I
Heart rate after a standardized test varies with a change in training status, possibly compromising the accuracy of measuring changes in heart rate recovery (HRR). The aim of this study was to determine if a change in the exercise intensity would result in a change in heart rate recovery and/or the accuracy of the heart rate recovery measurement. 31 subjects performed 4 submaximal running tests (HIMS). Based on the heart rate after the first HIMS, subjects either completed 4 identical HIMS (SAME (n=9)), 2 standard and 2 faster HIMS (FASTER (n=10)) or 2 standard and 2 slower HIMS (SLOWER (n=12)). Although no changes in heart rate recovery were found when the HIMS protocol was adapted, lower coefficients of variation (CV) and typical errors of measurement (TEM) were found in the SLOWER (CV: 11 ± 7 to 5 ± 3% ( P=0.025)), TEM: 6 to 3 beats and FASTER group (CV: 11 ± 7 to 4 ± 3% ( P=0.048), TEM: 7 to 3 beats). To ensure the highest level of sensitivity in detecting meaningful changes in HRR over time, submaximal testing protocols should target exercise intensities ranging in-between 86-93% of heart rate maximum. © Georg Thieme Verlag KG Stuttgart · New York.
Mullen, T. J.; Berger, R. D.; Oman, C. M.; Cohen, R. J.
In a study of 18 human subjects, we applied a new technique, estimation of the transfer function between instantaneous lung volume (ILV) and instantaneous heart rate (HR), to assess autonomic activity during motion sickness. Two control recordings of ILV and electrocardiogram (ECG) were made prior to the development of motion sickness. During the first, subjects were seated motionless, and during the second they were seated rotating sinusoidally about an earth vertical axis. Subjects then wore prism goggles that reverse the left-right visual field and performed manual tasks until they developed moderate motion sickness. Finally, ILV and ECG were recorded while subjects maintained a relatively constant level of sickness by intermittent eye closure during rotation with the goggles. Based on analyses of ILV to HR transfer functions from the three conditions, we were unable to demonstrate a change in autonomic control of heart rate due to rotation alone or due to motion sickness. These findings do not support the notion that moderate motion sickness is manifested as a generalized autonomic response.
Full Text Available As a passive, harmless, and low-cost diagnosis tool, fetal heart rate (FHR monitoring based on fetal phonocardiography (fPCG signal is alternative to ultrasonographic cardiotocography. Previous fPCG-based methods commonly relied on the time difference of detected heart sound bursts. However, the performance is unavoidable to degrade due to missed heart sounds in very low signal-to-noise ratio environments. This paper proposes a FHR monitoring method using repetition frequency of heart sounds. The proposed method can track time-varying heart rate without both heart sound burst identification and denoising. The average accuracy rate comparison to benchmark is 88.3% as the SNR ranges from −4.4 dB to −26.7 dB.
Kwon, Ji Young; Park, In Yang
The monitoring of fetal heart rate (FHR) status is an important method to check well-being of the baby during labor. Since the electronic FHR monitoring was introduced 40 years ago, it has been expected to be an innovative screening test to detect fetuses who are becoming hypoxic and who may benefit from cesarean delivery or operative vaginal delivery. However, several randomized controlled trials have failed to prove that electronic FHR monitoring had any benefit of reducing the perinatal mortality and morbidity. Also it is now clear that the FHR monitoring had high intra- and interobserver disagreements and increased the rate of cesarean delivery. Despite such limitations, the FHR monitoring is still one of the most important obstetric procedures in clinical practice, and the cardiotocogram is the most-used equipment. To supplement cardiotocogram, new methods of computerized FHR analysis and electrocardiogram have been developed, and several clinical researches have been currently performed. Computerized equipment makes us to analyze beat-to-beat variability and short term heart rate patterns. Furthermore, researches about multiparameters of FHR variability will be ongoing.
Pal, Nikhil; Sivaswamy, Nadiya; Mahmod, Masliza; Yavari, Arash; Rudd, Amelia; Singh, Satnam; Dawson, Dana K; Francis, Jane M; Dwight, Jeremy S; Watkins, Hugh; Neubauer, Stefan; Frenneaux, Michael; Ashrafian, Houman
Heart failure with preserved ejection fraction (HFpEF) is associated with significant morbidity and mortality but is currently refractory to therapy. Despite limited evidence, heart rate reduction has been advocated, on the basis of physiological considerations, as a therapeutic strategy in HFpEF. We tested the hypothesis that heart rate reduction improves exercise capacity in HFpEF. We conducted a randomized, crossover study comparing selective heart rate reduction with the If blocker ivabradine at 7.5 mg twice daily versus placebo for 2 weeks each in 22 symptomatic patients with HFpEF who had objective evidence of exercise limitation (peak oxygen consumption at maximal exercise [o2 peak] heart rate compared with placebo in the HFpEF (107 versus 129 bpm; Pheart rate reduction with ivabradine for improving symptoms in a HFpEF population characterized by exercise limitation. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02354573. © 2015 The Authors.
Full Text Available INTRODUCTION: Metabolic syndrome (MetS is described as a group of various abnormal metabolic risk factors such as obesity, dyslipidemia, increased blood pressure, increased plasma glucose levels, prothrombotic condition and proinflammatory state. These parameters are related to decreased parasympathetic and increased sympathetic activity. We aimed to evaluate autonomic function using a combination with heart rate variability (HRV and heart rate turbulence (HRT in metabolic syndrome to compare non-metabolic syndrome(non-MetS. METHODS: We selected consecutive 50 patients with MetS and 50 patients with healthy non-MetS individuals. All patients underwent 24 hours holter monitoring to evaluate HRT and HRV parameters. RESULTS: Age of patients was not different in two groups. Mean age of MetS patients was 57,50±12,13 and 54,6±10,25 in non- MetS individuals. Sex of patients was non different in MetS compared to non-MetS (37 female and 13 male vs. 22 female, 28 male p<0,05 respectively. SDNN and RMSSD was lower in MetS compared to those without MetS (131,96±49,12 vs 179,59±85,83 p=0,03 and 78,64±35,22 vs 112,73±81,24 p=0,08 respectively. SDANN, pNN50,Mean RR, mean heart rate, count of ventricular premature complex(VPC were not different between two groups. Turbulence Slope(TS was not different in two groups. Turbulence Onset(TO was higher in MetS compared to non-MetS (2,01±15,29 and -6,21±13,5 p=0,005. DISCUSSION AND CONCLUSION: We showed that autonomic function in MetS was impaired using a combination with HRT and HRV. These patients should be followed closely for adverse cardiovascular outcome especially including cardiac arrhythmia.
Chez, Bonnie Flood; Baird, Suzanne McMurtry
Electronic fetal heart rate monitoring (EFM) continues to be the primary method utilized for fetal assessment in the United States. Standardization of nomenclature associated with this perinatal technology has evolved over the past 40 years such that the current nomenclature recommended by the National Institute of Child Health and Human Development (NICHD) has been adopted by professional perinatal organizations as the agreed-upon method for professional communication and documentation. Current research continues to focus on the optimal management of intrapartum fetal heart rate tracings. The clinical controversies and challenges related to electronic fetal heart rate monitoring continue to evolve.
Full Text Available To determine the possible relationship between left ventricular dilatation and heart rate changes provoked by the Valsalva maneuver (Valsalva ratio, we studied 9 patients with isolated chronic aortic insufficiency. Left ventricular systolic function was assessed by two-dimensional echocardiography and cardiac catheterization. All patients were asymptomatic (functional class I of the New York Heart Association. The left ventricular internal diameters and volumes were significantly increased in all patients. The asymptomatic patients had either normal or slightly depressed ejection fraction (EF>0.40. The Valsalva ratio of these asymptomatic patients showed no significant correlation with the left ventricular volumes or with the left ventricular ejection fraction. In other words, parasympathetic heart rate control, as expressed by the Valsalva ratio, was normal in the asymptomatic patients with left ventricular dilatation and preserved left ventricular ejection fraction. Therefore, left ventricular dilatation may not be the major mechanism responsible for the abnormal parasympathetic heart rate control of patients with acquired heart disease
Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth
Autonomic modulation of heart rhythm is thought to influence the pathophysiology of myxomatous mitral valve disease (MMVD).......Autonomic modulation of heart rhythm is thought to influence the pathophysiology of myxomatous mitral valve disease (MMVD)....
Niu, Hui-Yan; Zhang, Dai-Fu; Liang, Bo
Objective To study the effect of exercise testing on short term heart rate variability in patients with CHD.Methods In 12 patients with CHD and 12 age-and sex-matched healthy controls, short-term frequency domain analysis was performed at respective stage before, during and after ET.Results It sh......Objective To study the effect of exercise testing on short term heart rate variability in patients with CHD.Methods In 12 patients with CHD and 12 age-and sex-matched healthy controls, short-term frequency domain analysis was performed at respective stage before, during and after ET...
Yin, De-Chun; Wang, Zhao-Jun; Guo, Shuai; Xie, Hong-Yu; Sun, Lin; Feng, Wei; Qiu, Wei; Qu, Xiu-Fen
This study is aimed to evaluate the clinical significance of heart rate turbulence (HRT) parameters in predicting the prognosis in patients with chronic heart failure (CHF). From June 2011 to December 2012, a total of 104 CHF patients and 30 healthy controls were enrolled in this study. We obtained a 24-hour Holter ECG recording to assess the HRT parameters, included turbulence onset (TO), turbulence slope (TS), standard deviation of N-N intervals (SDNN), and resting heart rate (RHR). The relationships between HRT parameters and the prognosis of CHF patients were determined. The assessment follow-up period lasted until January 31, 2013. The overall mortality of CHF patients was 9.6% (10/104). Our results revealed that CHF patients had higher levels of TO than those of healthy subjects, but the TS levels of CHF patients were lower than that of the control group. CHF patients with NYHA grade IV had higher HRT1/2 rate than those with NYHA grade II/III. There were statistical differences in TS, LVEF, SDNN and RHR between the non-deteriorating group and the non-survivor group. Significant differences in TS among the three groups were also found. Furthermore, CHF patients in the non-survivor group had lower levels of TS than those in the deteriorating group. Correlation analyses indicated that TO negatively correlate with SDNN, while TS positively correlated with SDNN and left ventricular ejection fraction (LVEF). We also observed negative correlations between TS and left ventricular end-diastolic cavity dimension (LVEDD), RHR, homocysteine (Hcy) and C-reactive protein (CRP). Multivariate Cox regression analysis further confirmed that LVEF (≤30%), HRT2, SDNN and RHR were independent risk factors which can indicate poor prognosis in CHF patients. Our findings indicate that HRT may have good clinical predictive value in patients with CHF. Thus, quantifying HRT parameters could be a useful tool for predicting mortality in CHF patients.
Full Text Available ABSTRACT In the present study, we investigated behavioural responses and determined parameters of heart rate variability (HRV to elucidate a relative activation of autonomic nervous system (ANS during baseline (10 min and in response to potentially stressful situations (10 min in two pig breeds and sexes. Gilts (n = 21 and barrows (n = 9 of the Landrace × Yorkshire (LY; n = 15 and Landrace/Yorkshire × Landrace/Duroc (LYLD; n = 15 breeds were subjected to a novel object test (NOT and a novel arena test (NAT. Basal ANS state differed in pigs across breeds but not sexes. Landrace × Yorkshire pigs had a significantly lower basal heart rate (HR and low-frequency band (LF with a higher root mean square of successive interbeat intervals (RMSSD and high-frequency band (HF than LYLD pigs. In the NOT, despite having similar cardiac responses, gilts had a longer duration of contact with a novel object, higher lying and standing duration, and a lower duration of walking compared with barrows. In the NAT, we found similar behaviour across sexes but a different degree of ANS state, with barrows having a significantly higher increase in LF/HF (power of the low frequency component divided by the power of the high-frequency band compared with gilts. Landrace/Yorkshire × Landrace/Duroc pigs showed longer duration of contact with a novel object in the NOT accompanied by less lying and standing than LY pigs in both tests. No difference in ANS activation between breeds was found in the NOT. In the NAT, HR increased more from baseline to testing in LY pigs than in LYLD pigs. There is a complex and often contradictory nature of relationships between behaviour and cardiac responses to novelty in pigs of different breeds and sexes.
Horton, John F; Stergiou, Pro; Fung, Tak S; Katz, Larry
The purpose of this study was to evaluate the accuracy of the Polar M600 optical heart rate (OHR) sensor compared with ECG heart rate (HR) measurement during various physical activities. Thirty-six subjects participated in a continuous 76-min testing session, which included rest, cycling warm-up, cycling intervals, circuit weight training, treadmill intervals, and recovery. HR was measured using a three-lead ECG configuration and a Polar M600 Sport Watch on the left wrist. Statistical analyses included OHR percent accuracy, mean difference, mean absolute error, Bland-Altman plots, and a repeated-measures generalized estimating equation design. OHR percent accuracy was calculated as the percentage of occurrences where OHR measurement was within and including ±5 bpm from the ECG HR value. Of the four exercise phases performed, the highest OHR percent accuracy was found during cycle intervals (91.8%), and the lowest OHR percent accuracy occurred during circuit weight training (34.5%). OHR percent accuracy improved steadily within exercise transitions during cycle intervals to a maximum of 98.5% and during treadmill intervals to a maximum of 89.0%. Lags in HR calculated by the Polar M600 OHR sensor existed in comparison to ECG HR, when exercise intensity changed until steady state occurred. There was a tendency for OHR underestimation during intensity increases and overestimation during intensity decreases. No statistically significant interaction effect with device was found in this sample on the basis of sex, body mass index, V˙O2max, skin type, or wrist size. The Polar M600 was accurate during periods of steady-state cycling, walking, jogging, and running, but less accurate during some exercise intensity changes, which may be attributed to factors related to total peripheral resistance changes and pulse pressure.
Fronczek, R.; Overeem, S.; Reijntjes, R.; Lammers, G.J.; Dijk, J.G.M.; Pijl, H.
STUDY OBJECTIVES: We investigated autonomic balance and resting metabolic rate to explore their possible involvement in obesity in hypocretin/orexin-deficient narcoleptic subjects. METHODS: Resting metabolic rate (using indirect calorimetry) and variability in heart rate and blood pressure were
Akyüz, Aydın; Alpsoy, Şeref; Akkoyun, Dursun Çayan; Güler, Niyazi
In order to evaluate the utility of the heart rate performance index (HRPI), which is obtained by dividing HR mean by the difference of HR max and HR min in the context of Holter monitoring, we sought to determine whether there was any correlation or relationship between the HRPI and LVEF values as determined by echocardiography and to compare the HRPI between the study and control groups. This study is a cross-sectional, controlled observational study. Thirty-two patients with symptomatic or asymptomatic left ventricular systolic dysfunction (LVEF heart failure (CHF) were included as a control group. In the study group, 10 patients were in NYHA class I (31.2%), 12 - were in NYHA class II (37.6%) and 10 - were in NYHA class III (31.2%). Heart rate analysis was measured using 24-hour Holter ambulatory electrocardiography. To determine the HRPI, the difference between maximum (HR max) and minimum heart rate (HR min) was divided by mean heart rate (HR mean) (beats/minute): HRPI=(HR max-HR min) / HR mean. Statistical analysis was performed using t-test for independent samples, Mann-Whitney U test, Chi-square test, Kruskal-Wallis test, Pearson's correlation and linear regression analyses. The HRPI index value was markedly decreased [0.83 (0.58-1.1) and 1.10 (0.74-1.3), pheart rate derivatives (unstandardized β=42.43 95% CI: 21.98-50.51, p=0.231). According to our findings, patients with CHF exhibited higher HR mean values, reduced HR max-min values and significantly decreased HRPI values. There is a positive correlation between HRPI and LVEF, a decreased HRPI is associated with a decreased LVEF, but there is no relationship between these two variables. Therefore, HRPI values may represent a viable option for assessing daily exercise activity and potentially sympathetic activation in patients with CHF. The assessment of HRPI may be helpful the evaluation of CHF patients, as well as resting HR.
Summary. The effect of pregnancy on the heart rate, respiratory rate,. QRS axis and QRS complex duration of the ECG was investigated in 41 pregnant compared to 39 non pregnant age and height matched Nigerian subjects. Results obtained show that pregnancy had no signiﬁcant effect (p>0.05) on heart rate, respiratory ...
Das, Sangita; Pal, Saurabh; Mitra, Madhuchhanda
This paper introduces a noise robust real time heart rate detection system from electrocardiogram (ECG) data. An online data acquisition system is developed to collect ECG signals from human subjects. Heart rate is detected using window-based autocorrelation peak localisation technique. A low-cost Arduino UNO board is used to implement the complete automated process. The performance of the system is compared with PC-based heart rate detection technique. Accuracy of the system is validated through simulated noisy ECG data with various levels of signal to noise ratio (SNR). The mean percentage error of detected heart rate is found to be 0.72% for the noisy database with five different noise levels.
Pretlow, Robert A., III; Stoughton, John W.
Research and development is presented of real time signal processing methodologies for the detection of fetal heart tones within a noise-contaminated signal from a passive acoustic sensor. A linear predictor algorithm is utilized for detection of the heart tone event and additional processing derives heart rate. The linear predictor is adaptively 'trained' in a least mean square error sense on generic fetal heart tones recorded from patients. A real time monitor system is described which outputs to a strip chart recorder for plotting the time history of the fetal heart rate. The system is validated in the context of the fetal nonstress test. Comparisons are made with ultrasonic nonstress tests on a series of patients. Comparative data provides favorable indications of the feasibility of the acoustic monitor for clinical use.
Topçu, Çağdaş; Frühwirth, Matthias; Moser, Maximilian; Rosenblum, Michael; Pikovsky, Arkady
Different measures of heart rate variability and particularly of respiratory sinus arrhythmia are widely used in research and clinical applications. Inspired by the ideas from the theory of coupled oscillators, we use simultaneous measurements of respiratory and cardiac activity to perform a nonlinear decomposition of the heart rate variability into the respiratory-related component and the rest. We suggest to exploit the technique as a universal preprocessing tool, both for the analysis of r...
Matthew P Wallen
Full Text Available Wrist-worn monitors claim to provide accurate measures of heart rate and energy expenditure. People wishing to lose weight use these devices to monitor energy balance, however the accuracy of these devices to measure such parameters has not been established.To determine the accuracy of four wrist-worn devices (Apple Watch, Fitbit Charge HR, Samsung Gear S and Mio Alpha to measure heart rate and energy expenditure at rest and during exercise.Twenty-two healthy volunteers (50% female; aged 24 ± 5.6 years completed ~1-hr protocols involving supine and seated rest, walking and running on a treadmill and cycling on an ergometer. Data from the devices collected during the protocol were compared with reference methods: electrocardiography (heart rate and indirect calorimetry (energy expenditure.None of the devices performed significantly better overall, however heart rate was consistently more accurate than energy expenditure across all four devices. Correlations between the devices and reference methods were moderate to strong for heart rate (0.67-0.95 [0.35 to 0.98] and weak to strong for energy expenditure (0.16-0.86 [-0.25 to 0.95]. All devices underestimated both outcomes compared to reference methods. The percentage error for heart rate was small across the devices (range: 1-9% but greater for energy expenditure (9-43%. Similarly, limits of agreement were considerably narrower for heart rate (ranging from -27.3 to 13.1 bpm than energy expenditure (ranging from -266.7 to 65.7 kcals across devices.These devices accurately measure heart rate. However, estimates of energy expenditure are poor and would have implications for people using these devices for weight loss.
Laskey, Warren K.; Alomari, Ihab; Cox, Margueritte; Schulte, Phillip J.; Zhao, Xin; Hernandez, Adrian F.; Heidenreich, Paul A.; Eapen, Zubin J.; Yancy, Clyde; Bhatt, Deepak L.; Fonarow, Gregg C.
Background Whether heart rate upon discharge following hospitalization for heart failure is associated with long‐term adverse outcomes and whether this association differs between patients with sinus rhythm (SR) and atrial fibrillation (AF) have not been well studied. Methods and Results We conducted a retrospective cohort study from clinical registry data linked to Medicare claims for 46 217 patients participating in Get With The Guidelines®–Heart Failure. Cox proportional‐hazards models were used to estimate the association between discharge heart rate and all‐cause mortality, all‐cause readmission, and the composite outcome of mortality/readmission through 1 year. For SR and AF patients with heart rate ≥75, the association between heart rate and mortality (expressed as hazard ratio [HR] per 10 beats‐per‐minute increment) was significant at 0 to 30 days (SR: HR 1.30, 95% CI 1.22 to 1.39; AF: HR 1.23, 95% CI 1.16 to 1.29) and 31 to 365 days (SR: HR 1.15, 95% CI 1.12 to 1.20; AF: HR 1.05, 95% CI 1.01 to 1.08). Similar associations between heart rate and all‐cause readmission and the composite outcome were obtained for SR and AF patients from 0 to 30 days but only in the composite outcome for SR patients over the longer term. The HR from 0 to 30 days exceeded that from 31 to 365 days for both SR and AF patients. At heart rates heart failure, higher discharge heart rate was associated with increased risks of death and rehospitalization, with higher risk in the first 30 days and for SR compared with AF. PMID:25904590
Osorio, Ivan; Manly, B F J
Heart rate-based seizure detection is a viable complement or alternative to ECoG/EEG. This study investigates the role of various biological factors on the probability of clinical seizure detection using heart rate. Regression models were applied to 266 clinical seizures recorded from 72 subjects to investigate if factors such as age, gender, years with epilepsy, etiology, seizure site origin, seizure class, and data collection centers, among others, shape the probability of EKG-based seizure detection. Clinical seizure detection probability based on heart rate changes, is significantly (pprobability of detecting clinical seizures (>0.8 in the majority of subjects) using heart rate is highest for complex partial seizures, increases with a patient's years with epilepsy, is lower for females than for males and is unrelated to the side of hemisphere origin. Clinical seizure detection probability using heart rate is multi-factorially dependent and sufficiently high (>0.8) in most cases to be clinically useful. Knowledge of the role that these factors play in shaping said probability will enhance its applicability and usefulness. Heart rate is a reliable and practical signal for extra-cerebral detection of clinical seizures originating from or spreading to central autonomic network structures. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.
Gao, X. Z.; Ching, E. S. C.; Lin, D. C.
We show a hierarchical structure (HS) of the She-Leveque form in the beat-to-beat RR intervals of heart rate variability (HRV) in humans. This structure, first found as an empirical law in turbulent fluid flows, implies further details in the HRV multifractal scaling. We tested HS using daytime RRi data from healthy subjects and heart diseased patients with congestive heart failure and found a universal law C(b) where b characterizes the multifractality of HRV and C is related to a co-dimension parameter of the most violent events in the fluctuation. The potential of diagnosis is discussed based on the characteristics of this finding. To model the HRV phenomenology, we propose a local-feedback-global-cascade (LFGC) model based on the She-Waymire (SW) cascade solution to the HS in fluid turbulence. This model extends from the previous work in that it integrates additive law multiplicatively into the cascade structure. It is an attempt to relate to the cardiovascular physiology which consists of numerous feedback controls that function primarily on the principle of additive law. In particular, the model is based on the same philosophy as the SW cascade that its multifractal dynamics consists of a singular and a modulating component. In the LFGC model, we introduce local feedback to model the dynamics of the modulating effect. The novelty of our model is to incorporate the cascade structure in the scheduling for the feedback control. This model also represents an alternative solution to the HS. We will present the simulation results by the LFGC model and discuss its implication in physiology terms.
Vollono, Catello; Gnoni, Valentina; Testani, Elisa; Dittoni, Serena; Losurdo, Anna; Colicchio, Salvatore; Di Blasi, Chiara; Mazza, Salvatore; Farina, Benedetto; Della Marca, Giacomo
This is an observational study aimed to investigate the activity of autonomic nervous system during sleep in patients with sleep-related migraine. Eight consecutive migraineurs without aura were enrolled (6 women and 2 men), aged 30 to 62 years (mean 48.1 ± 9.3 years). Inclusion criteria were: high frequency of attacks (> 5 per month) and occurrence of more than 75% of the attacks during sleep causing an awakening. Patients were compared with a control group of 55 healthy subjects (23 men and 32 women, mean age 54.2 ± 13.0 years), and with a further control group of 8 age- and gender-matched healthy controls. Patient and controls underwent polysomnography and heart rate variability analysis. A significant reduction of the LF/HF ratio during N2 and N3 sleep stages was observed in migraineurs compared with controls. No differences in sleep macrostructure were observed; cyclic alternating pattern (CAP) time and CAP rate were lower in migraineurs than in controls. These findings indicate a peculiar modification of the autonomic balance during sleep in sleep-related migraine. The reduction of LF/HF ratio in NREM sleep was observed in controls, but it was quantitatively much more evident in migraineurs. Changes in LF/HF could be consequent to an autonomic unbalance which could manifest selectively (or alternatively become more evident) during sleep. These findings, together with the reduction in CAP rate, could be an expression of reduced arousability during sleep in patients with sleep-related migraine. The simultaneous involvement of the autonomic, arousal, and pain systems might suggest involvement of the hypothalamic pathways.
Dural, Muhammet; Kabakcı, Giray; Cınar, Neşe; Erbaş, Tomris; Canpolat, Uğur; Gürses, Kadri Murat; Tokgözoğlu, Lale; Oto, Ali; Kaya, Ergün Barış; Yorgun, Hikmet; Sahiner, Levent; Dağdelen, Selçuk; Aytemir, Kudret
Cardiovascular complications are the most common causes of morbidity and mortality in acromegaly. However, there is little data regarding cardiac autonomic functions in these patients. Herein, we aimed to investigate several parameters of cardiac autonomic functions in patients with acromegaly compared to healthy subjects. We enrolled 20 newly diagnosed acromegalic patients (55% female, age:45.7 ± 12.6 years) and 32 age- and gender-matched healthy subjects. All participants underwent 24 h Holter recording. Heart rate recovery (HRR) indices were calculated by subtracting 1st, 2nd and 3rd minute heart rates from maximal heart rate. All patients underwent heart rate variability (HRV) and QT dynamicity analysis. Baseline characteristics were similar except diabetes mellitus and hypertension among groups. Mean HRR1 (29.2 ± 12.3 vs 42.6 ± 6.5, p = 0.001), HRR2 (43.5 ± 15.6 vs 61.1 ± 10.8, p = 0.001) and HRR3 (46.4 ± 16.2 vs 65.8 ± 9.8, p = 0.001) values were significantly higher in control group. HRV parameters as, SDNN [standard deviation of all NN intervals] (p = 0.001), SDANN [SD of the 5 min mean RR intervals] (p = 0.001), RMSSD [root square of successive differences in RR interval] (p = 0.001), PNN50 [proportion of differences in successive NN intervals >50 ms] (p = 0.001) and high-frequency [HF] (p = 0.001) were significantly decreased in patients with acromegaly; but low frequency [LF] (p = 0.046) and LF/HF (p = 0.001) were significantly higher in acromegaly patients. QTec (p = 0.009), QTac/RR slope (p = 0.017) and QTec/RR slope (p = 0.01) were significantly higher in patients with acromegaly. Additionally, there were significant negative correlation of disease duration with HRR2, HRR3, SDNN, PNN50, RMSSD, variability index. Our study results suggest that cardiac autonomic functions are impaired in patients with acromegaly. Further large scale studies are needed to exhibit the prognostic significance of impaired autonomic functions in patients with
Szymanowska, Katarzyna; Piatkowska, Anna; Nowicka, Anna; Michalski, Marek; Dankowski, Rafał; Kandziora, Magdalena; Biegalski, Wojciech; Wierzchowiecki, Michał; Poprawski, Kajetan
Heart rate turbulence (HRT) is modulated by the baroreceptor reflex, and it has been suggested that it could be used as a measure of autonomic dysfunction. Impaired HRT has a significant prognostic value in patients after myocardial infarction. The usefulness of HRT parameters in CHF patients has not yet been well established. To assess the relationship between HRT parameters, clinical course of CHF and selected biochemical markers with respect to their prognostic value in CHF patients. A 64 of 100 consecutive CHF patients, in whom it was possible to calculate HRT, were divided into four groups according to NYHA class. Uric acid (UA) and brain natriuretic peptide (BNP) concentrations were measured. Heart rate turbulence was analysed from 24-hour Holter ECG and characterised by two parameters: turbulence onset (TO) and turbulence slope (TS). The results of 20 healthy persons served as a control group. Follow-up examinations were performed after 6 and 12 months. In patients with CHF both HRT parameters (TO and TS) were significantly impaired in comparison to TO and TS in healthy subjects. A negative correlation between these parameters was found. A strong positive correlation between TO and NYHA class and a significant negative correlation between TS and BNP and UA concentrations were observed. There were 11 deaths during one-year follow-up. Patients who died due to CHF had significantly lower TS and higher TO values in comparison to survivors. Heart rate turbulence is impaired in CHF patients. HRT parameters show a significant correlation with some clinical factors: NYHA class, BNP and UA concentrations. Both HRT parameters, TO and TS, seem to be significant prognostic markers in patients with CHF.
Segovia, Victoria; Manterola, Carlos; González, Marcelo; Rodríguez-Núñez, Iván
Cardiovascular diseases are a significant cause of morbidity and mortality in the general population. In this sense, the autonomic imbalance is the cornerstone of the pathophysiology underlying the development of these diseases. The aim of this study was to determine the efficacy of exercise training on heart rate variability (HRV) in adult patients with chronic heart failure. A systematic literature review was conducted in electronic databases. The considered studies were randomised clinical trials, quasi-experimental studies with non-randomised control group, quasi-experimental studies with analysis of pre- and post- intervention, and crossover studies with randomly assigned training and non-training periods. The standardised mean differences were calculated between pre- and post-intervention in both the control and experimental group. Within-subject analysis of the control group showed no statistical significance in the standardised mean differences of HRV. In the experimental group, the standardised mean differences were positive for the root mean square of successive difference (+0.468±0.215; P=.032), high frequency band (HF) (0.934±0.256; P < .001) and low frequency band (LF) (< 0.415±0.096; P=.001). Moreover, the standardised mean difference was negative for LF/HF (-0.747±0.369, P=<.044). On the other hand, only 3 studies entered the comparative meta-analysis. The effect of exercise training was favourable for the experimental group in LF/HF (-2.21±95% CI: -3.83 to -0.60), HF, and LF. The exercise training was effective in increasing HRV and restoring the autonomic balance in patients with heart failure. Copyright © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.
Michael M. Knepp; Erin R. Krafka; Erika M. Druzina
High anxiety and poor emotion regulation have been found to function as independent causes of stress to the autonomic nervous system. The aim of this study was to further explore how these factors may interact to control heart rate variability. Fifty college students took part in a three-part cardiac recording session followed by questionnaires on trait worry and emotion regulation. An interaction for trait worry and emotion reappraisal was found on two markers of heart rate variability. Low ...
Georgieva, A. E.; Payne, S. J.; Moulden, M.; Redman, C. W. G.
Electronic fetal heart rate (FHR) recording is a standard way of monitoring fetal health in labor. Decelerations and accelerations usually indicate fetal distress and normality respectively. But one type of acceleration may differ, namely an overshoot that may atypically reflect fetal stress. Here we describe a new method for detecting decelerations, accelerations and overshoots as part of a novel system for computerized FHR analysis (OxSyS). There was poor agreement between clinicians when identifying these FHR features visually, which precluded setting a gold standard of interpretation. We therefore introduced `modified' Sensitivity (SE°) and `modified' Positive Predictive Value (PPV°) as appropriate performance measures with which the algorithm was optimized. The relation between overshoots and fetal compromise in labor was studied in 15 cases and 15 controls. Overshoots showed promise as an indicator of fetal compromise. Unlike ordinary accelerations, overshoots cannot be considered to be reassuring features of fetal health.
MALCHAIRE, Jacques; ALFANO, Francesca Romana d?AMBROSIO; PALELLA, Boris Igor
The assessment of harsh working conditions requires a correct evaluation of the metabolic rate. This paper revises the basis described in the ISO 8996 standard for the evaluation of the metabolic rate at a work station from the recording of the heart rate of a worker during a representative period of time. From a review of the literature, formulas different from those given in the standard are proposed to estimate the maximum working capacity, the maximum heart rate, the heart rate and the me...
Kayacan, Yildirim; Yildiz, Sedat
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.
van Leeuwen, P.; Cysarz, D.; Lange, S.; Geue, D.; Groenemeyer, D.
Fetal heart rate complexity was examined on the basis of RR interval time series obtained in the second and third trimester of pregnancy. In each fetal RR interval time series, short term beat-to-beat heart rate changes were coded in 8bit binary sequences. Redundancies of the 28 different binary patterns were reduced by two different procedures. The complexity of these sequences was quantified using the approximate entropy (ApEn), resulting in discrete ApEn values which were used for classifying the sequences into 17 pattern sets. Also, the sequences were grouped into 20 pattern classes with respect to identity after rotation or inversion of the binary value. There was a specific, nonuniform distribution of the sequences in the pattern sets and this differed from the distribution found in surrogate data. In the course of gestation, the number of sequences increased in seven pattern sets, decreased in four and remained unchanged in six. Sequences that occurred less often over time, both regular and irregular, were characterized by patterns reflecting frequent beat-to-beat reversals in heart rate. They were also predominant in the surrogate data, suggesting that these patterns are associated with stochastic heart beat trains. Sequences that occurred more frequently over time were relatively rare in the surrogate data. Some of these sequences had a high degree of regularity and corresponded to prolonged heart rate accelerations or decelerations which may be associated with directed fetal activity or movement or baroreflex activity. Application of the pattern classes revealed that those sequences with a high degree of irregularity correspond to heart rate patterns resulting from complex physiological activity such as fetal breathing movements. The results suggest that the development of the autonomic nervous system and the emergence of fetal behavioral states lead to increases in not only irregular but also regular heart rate patterns. Using symbolic dynamics to
TUININGA, YS; VANVELDHUISEN, DJ; BROUWER, J; HAAKSMA, J; CRIJNS, HJGM; MANINTVELD, AJ; LIE, KI
Objective-To review the importance of heart rate variability analysis in left ventricular dysfunction and heart failure and to assess the effects of drug treatment. In patients with left: ventricular dysfunction or heart failure, a low heart rate variability is a strong predictor of a low
Javed, Omar; Koo, Kenneth; El-Omar, Omar; Allen, Stuart; Squires, Alexander; El-Omar, Magdi
The prognostic benefit from heart rate (HR) reduction in patients with ischaemic heart disease (IHD) and/or chronic heart failure (CHF) is now firmly established. Most decisions regarding initiation and/or dose adjustment of HR-limiting medications in such patients are based on clinic HR. Yet, this is a highly variable parameter that may not necessarily reflect HR control over the 24 h period. To examine the level of agreement between mean clinic and mean ambulatory HRs in patients with IHD and/or CHF taking rate-limiting medications. Prospective, observational study. Fifty patients with IHD and/or CHF who attended cardiology outpatient clinics at the Manchester Heart Centre and underwent same-day 24 h continuous ECG recording between March and October 2013 were included in the study. Mean clinic HR was compared with mean 24 h, daytime and night-time HRs. Limits-of-agreement plots were constructed to examine the relationship between the two HR measures in more detail. The mean clinic HR was numerically similar to the mean HRs of all ambulatory time periods examined. However, on Bland-Altman plots, the limits of agreement between clinic and ambulatory HR means were quite wide, with the mean clinic HR ranging between 10.93 and 13.58 bpm below and 8.4 and 18.15 bpm above the mean ambulatory HR. Although numerically similar, the means of clinic and ambulatory HRs in patients with IHD and/or CHF display wide limits of agreement. As such, the two measures cannot be regarded as interchangeable. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
A light-weight micro-cassette recorder was used to document the subjects' verbalised thoughts while training. Effort was measured by the rate of perceived exertion (RPE) at the completion of each ride, and through the recording of heart rate every 60 seconds. A cycling-specific sub-category of thought ";equipment ...
Nichols, Randall; Davis, Kathryn L.; McCord, Tim; Schmidt, Dave; Slezak, Alex M.
The ever-rising rate of obesity and the need for increased physical activity for young children is well documented. Data suggests that today's youth are not participating in enough quality health-enhancing physical activity either in or outside of school. Heart rate monitors have been used by adult exercisers for many years to monitor and assess…
Strupler, M.; Muller, G.; Perret, C.
OBJECTIVE: To find the individual intensity for aerobic endurance training, the lactate minimum test (LMT) seems to be a promising method. LMTs described in the literature consist of speed or work rate-based protocols, but for training prescription in daily practice mostly heart rate is used. The
Full Text Available In our work, we analyzed the effect of training load on the heart rate of horses in a simulated load by the loading regulator for horse motion Horse Gym 2000. In the experiment were observed 8 Slovak Warmblood horses (3 mares, 4 geldings, 1 stallion aged 6-10 years. The experiment was divided into two parts after three weeks. The speed of the tested horses was 4.9 km/h in the first part of experiment, in the second part was the speed 5.2 km/h with a gradual uphill up to 7 %. The tested horses achieved during the experiment an average heart rate level below 70 beats a minute, which is a light load. The maximum values of heart rate were recorded at 120 to 147 beats/min. Differences between tested horses in the values of heart rate were not statistically significant. After three weeks we recorded in the values of average and maximum heart rate onset of bradycardia, which is documented the adaptation of body to the specified load.
Lowenstein, Lior; Mustafa, Mona; Burke, Yechiel Z; Mustafa, Susana; Segal, Dror; Weissman, Amir
The objective of this study was to evaluate heart rate variability and hemodynamic parameters following steep Trendelenburg positioning during robotic sacrocolpopexy. For 19 women, median age 57 (range: 45-72), blood pressure and ECG were recorded during surgery. From the ECG signals interbeat intervals were used to assess heart rate variability, analyzed in time and frequency domains using the Fast Fourier transform. The low frequency and high frequency spectral bands were used to assess sympathetic and parasympathetic pathways respectively. All women underwent robotic supracervical hysterectomy and sacrocolpopexy. A statistically significant decrease in the mean values of the low-frequency and high-frequency spectral bands, representing sympathetic and parasympathetic activity, respectively were demonstrated 5min following Trendelenburg positioning of the patients (from 3.6±1.4 to 2.9±0.8ms(2)/Hz, and from 3.5±1.4 to 2.9±1ms(2)/Hz, Pchanges correlated with a mean 20% decrease in heart rate, which lasted for 30min, and with a second drop in sympathetic and parasympathetic activity and heart rate, commencing 2h from the start of surgery, and lasting until the end of the operation. Steep Tredelenburg positioning during robotic urogynecology surgery results in significant changes in the autonomic nervous system modulation of heart rate variability and in other hemodynamic parameters. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Xu, Fang; Zhou, Qin-Wu; Wu, Peng; Chen, Xing; Yang, Xiaofeng; Yan, Hong-jian
This paper proposes a new non-contact heart rate measurement method based on photoplethysmography (PPG) theory. With this method we can measure heart rate remotely with a camera and ambient light. We collected video sequences of subjects, and detected remote PPG signals through video sequences. Remote PPG signals were analyzed with two methods, Blind Source Separation Technology (BSST) and Cross Spectral Power Technology (CSPT). BSST is a commonly used method, and CSPT is used for the first time in the study of remote PPG signals in this paper. Both of the methods can acquire heart rate, but compared with BSST, CSPT has clearer physical meaning, and the computational complexity of CSPT is lower than that of BSST. Our work shows that heart rates detected by CSPT method have good consistency with the heart rates measured by a finger clip oximeter. With good accuracy and low computational complexity, the CSPT method has a good prospect for the application in the field of home medical devices and mobile health devices.
González-Landaeta, R; Casas, O; Pallàs-Areny, R
We propose a novel technique for heart rate detection on a subject that stands on a common electronic weighing scale. The detection relies on sensing force variations related to the blood acceleration in the aorta, works even if wearing footwear, and does not require any sensors attached to the body. We have applied our method to three different weighing scales, and estimated whether their sensitivity and frequency response suited heart rate detection. Scale sensitivities were from 490 nV/V/N to 1670 nV/V/N, all had an underdamped transient response and their dynamic gain error was below 19% at 10 Hz, which are acceptable values for heart rate estimation. We also designed a pulse detection system based on off-the-shelf integrated circuits, whose gain was about 70x10(3) and able to sense force variations about 240 mN. The signal-to-noise ratio (SNR) of the main peaks of the pulse signal detected was higher than 48 dB, which is large enough to estimate the heart rate by simple signal processing methods. To validate the method, the ECG and the force signal were simultaneously recorded on 12 volunteers. The maximal error obtained from heart rates determined from these two signals was +/-0.6 beats/minute.
Ali Metin Esen
Full Text Available Summary: Atrial fibrillation (AF is known to be one of the most important complications of mitral stenosis (MS. It has been reported that autonomic nervous system (ANS had an effect on AF development, heart rate variability (HRV and heart rate recovery (HRR were under the control of ANS, and their disorders were present in MS. We studied the effect of Valsartan on HRV and HRT, and thus its effect on ANS. Methods: Eleven patients (39±8 years, 10 females with mild to moderate MS were included in the study. Sixteen volunteers (38±8 years, 14 females matched for age and sex were selected for control group. All subjects underwent transthoracic echocardiography (TTE, symptom-limited treadmill test and 24 hour Holter monitorization.The patients were administered 160 mg of Valsartan daily for 14 weeks. TTE, treadmill test and Holter monitorization were repeated at the end of treatment period. In Holter monitorization, the time and frequency domain analysis of HRV and in exercise test, HRR at first and third minutes (HRR1 and HRR3 were examined. Results: Before Valsartan treatment, no significant difference was found in HRR and HRV parameters between the two groups. Systolic and diastolic blood pressure, and also HRR1values were significantly decreased after treatment of Valsartan (117±6 vs. 107±4 mmHg p<0.002, 76±6 vs. 69±9 mmHg p<0.044, 44±14 vs. 33±12 p< 0.014, respectively, while the exercise time was significantly increased (786±114 vs. 846±95 sn p< 0.044. In Holter analysis neither time nor frequency domain of HRV parameters showed a meaningful change. Conclusion: In moderate MS, treatment with Valsartan improved the effort capacity, while autonomic function parameters have been defined on the base of HRV and HRR were not significantly different.
Gorny, Alexander Wilhelm; Liew, Seaw Jia; Tan, Chuen Seng; Müller-Riemenschneider, Falk
Many modern smart watches and activity trackers feature an optical sensor that estimates the wearer's heart rate. Recent studies have evaluated the performance of these consumer devices in the laboratory. The objective of our study was to examine the accuracy and sensitivity of a common wrist-worn tracker device in measuring heart rates and detecting 1-min bouts of moderate to vigorous physical activity (MVPA) under free-living conditions. Ten healthy volunteers were recruited from a large university in Singapore to participate in a limited field test, followed by a month of continuous data collection. During the field test, each participant would wear one Fitbit Charge HR activity tracker and one Polar H6 heart rate monitor. Fitbit measures were accessed at 1-min intervals, while Polar readings were available for 10-s intervals. We derived intraclass correlation coefficients (ICCs) for individual participants comparing heart rate estimates. We applied Centers for Disease Control and Prevention heart rate zone cut-offs to ascertain the sensitivity and specificity of Fitbit in identifying 1-min epochs falling into MVPA heart rate zone. We collected paired heart rate data for 2509 1-min epochs in 10 individuals under free-living conditions of 3 to 6 hours. The overall ICC comparing 1-min Fitbit measures with average 10-s Polar H6 measures for the same epoch was .83 (95% CI .63-.91). On average, the Fitbit tracker underestimated heart rate measures by -5.96 bpm (standard error, SE=0.18). At the low intensity heart rate zone, the underestimate was smaller at -4.22 bpm (SE=0.15). This underestimate grew to -16.2 bpm (SE=0.74) in the MVPA heart rate zone. Fitbit devices detected 52.9% (192/363) of MVPA heart rate zone epochs correctly. Positive and negative predictive values were 86.1% (192/223) and 92.52% (2115/2286), respectively. During subsequent 1 month of continuous data collection (270 person-days), only 3.9% of 1-min epochs could be categorized as MVPA according
Wessel, Niels; Riedl, Maik; Kurths, Jürgen
The incidence of cardiovascular diseases increases with the growth of the human population and an aging society, leading to very high expenses in the public health system. Therefore, it is challenging to develop sophisticated methods in order to improve medical diagnostics. The question whether the normal heart rate is chaotic or not is an attempt to elucidate the underlying mechanisms of cardiovascular dynamics and therefore a highly controversial topical challenge. In this contribution we demonstrate that linear and nonlinear parameters allow us to separate completely the data sets of the three groups provided for this controversial topic in nonlinear dynamics. The question whether these time series are chaotic or not cannot be answered satisfactorily without investigating the underlying mechanisms leading to them. We give an example of the dominant influence of respiration on heart beat dynamics, which shows that observed fluctuations can be mostly explained by respiratory modulations of heart rate and blood pressure (coefficient of determination: 96%). Therefore, we recommend reformulating the following initial question: "Is the normal heart rate chaotic?" We rather ask the following: "Is the normal heart rate `chaotic' due to respiration?"
Pambudi Utomo, Trio; Nuryani, Nuryani; Darmanto
In this study, Android smartphone is used for heart rate monitoring and displaying electrocardiogram (ECG) graph. Heart rate determination is based on QRS peak detection. Two methods are studied to detect the QRS complex peak; they are Peak Threshold and Peak Filter. The acquisition of ECG data is utilized by AD8232 module from Analog Devices, three electrodes, and Microcontroller Arduino UNO R3. To record the ECG data from a patient, three electrodes are attached to particular body’s surface of a patient. Patient’s heart activity which is recorded by AD8232 module is decoded by Arduino UNO R3 into analog data. Then, the analog data is converted into a voltage value (mV) and is processed to get the QRS complex peak. Heart rate value is calculated by Microcontroller Arduino UNO R3 uses the QRS complex peak. Voltage, heart rate, and the QRS complex peak are sent to Android smartphone by Bluetooth HC-05. ECG data is displayed as the graph by Android smartphone. To evaluate the performance of QRS complex peak detection method, three parameters are used; they are positive predictive, accuracy and sensitivity. Positive predictive, accuracy, and sensitivity of Peak Threshold method is 92.39%, 70.30%, 74.62% and for Peak Filter method are 98.38%, 82.47%, 83.61%, respectively.
Roubille, François; Tournoux, François; Roubille, Camille; Merlet, Nolwenn; Davy, Jean-Marc; Rhéaume, Eric; Busseuil, David; Tardif, Jean-Claude
Rest is usually recommended in acute pericarditis and acute myocarditis. Given that myocarditis often leads to hospitalization, this task seems easy to carry out in hospital practice; however, it could be a real challenge at home in daily life. Heart rate-lowering treatments (mainly beta-blockers) are usually recommended in case of acute myocarditis, especially in case of heart failure or arrhythmias, but level of proof remains weak. Calcium channel inhibitors and digoxin are sometimes proposed, albeit in limited situations. It is possible that rest or even heart rate-lowering treatments could help to manage these patients by preventing heart failure as well as by limiting "mechanical inflammation" and controlling arrhythmias, especially life-threatening ones. Whether heart rate has an effect on inflammation remains unclear. Several questions remain unsolved, such as the duration of such treatments, especially in light of new heart rate-lowering treatments, such as ivabradine. In this review, we discuss rest and heart-rate lowering medications for the treatment of pericarditis and myocarditis. We also highlight some work in experimental models that indicates the beneficial effects of such treatments for these conditions. Finally, we suggest certain experimental avenues, through the use of animal models and clinical studies, which could lead to improved management of these patients. Copyright © 2013 Elsevier Masson SAS. All rights reserved.
Linneberg, Allan; Jacobsen, Rikke K; Skaaby, Tea
BACKGROUND: -Smoking is an important cardiovascular disease risk factor, but the mechanisms linking smoking to blood pressure are poorly understood. METHODS AND RESULTS: -Data on 141,317 participants (62,666 never, 40,669 former, 37,982 current smokers) from 23 population-based studies were...... included in observational and Mendelian randomisation (MR) meta-analyses of the associations of smoking status and smoking heaviness with systolic and diastolic blood pressure (SBP, DBP), hypertension, and resting heart rate. For the MR analyses, a genetic variant rs16969968/rs1051730 was used as a proxy...... association of smoking heaviness with higher level of resting heart rate, but not with blood pressure. These findings suggest that part of the cardiovascular risk of smoking may operate through increasing resting heart rate....
Rosenberg-Adamsen, S; Lie, C; Bernhard, A
. METHODS: The authors studied the effect of oxygen therapy on arterial oxygen saturation and heart rate in 100 consecutive unselected patients randomly and double blindly allocated to receive air or oxygen therapy between the first and fourth day after major abdominal surgery. RESULTS: The median arterial...... supplementation were found between patients with or without an epidural catheter or between the postoperative day studied. CONCLUSION: Postoperative oxygen therapy increased arterial oxygen saturation and decreased heart rate after uncomplicated abdominal surgery in a consecutive unselected group of patients who......BACKGROUND: Cardiac complications are common during the postoperative period and may be associated with hypoxemia and tachycardia. Preliminary studies in high-risk patients after operation have shown a possible beneficial effect of oxygen therapy on arterial oxygen saturation and heart rate...
Clark, Steven L; Hamilton, Emily F; Garite, Thomas J; Timmins, Audra; Warrick, Philip A; Smith, Samuel
Despite intensive efforts directed at initial training in fetal heart rate interpretation, continuing medical education, board certification/recertification, team training, and the development of specific protocols for the management of abnormal fetal heart rate patterns, the goals of consistently preventing hypoxia-induced fetal metabolic acidemia and neurologic injury remain elusive. The purpose of this study was to validate a recently published algorithm for the management of category II fetal heart rate tracings, to examine reasons for the birth of infants with significant metabolic acidemia despite the use of electronic fetal heart rate monitoring, and to examine critically the limits of electronic fetal heart rate monitoring in the prevention of neonatal metabolic acidemia. The potential performance of electronic fetal heart rate monitoring under ideal circumstances was evaluated in an outcomes-blinded examination fetal heart rate tracing of infants with metabolic acidemia at birth (base deficit, >12) and matched control infants (base deficit, fetal heart rate tracings, followed by delivery within 30 minutes, (4) evaluation without the need to provide patient care simultaneously, and (5) comparison of results under these circumstances with those achieved in actual clinical practice. During the study period, 120 infants were identified with an arterial cord blood base deficit of >12 mM/L. Matched control infants were not demographically different from subjects. In actual practice, operative intervention on the basis of an abnormal fetal heart rate tracings occurred in 36 of 120 fetuses (30.0%) with metabolic acidemia. Based on expert, algorithm-assisted reviews, 55 of 120 patients with acidemia (45.8%) were judged to need operative intervention for abnormal fetal heart rate tracings. This difference was significant (P=.016). In infants who were born with a base deficit of >12 mM/L in which blinded, algorithm-assisted expert review indicated the need for
... Disease and Stroke email updates Enter email Submit Heart disease risk factors you can't control Some factors ... 2013). Hypertension in Pregnancy. Previous Page Next Page Heart disease resources Related information Heart-healthy eating Stress and ...
Full Text Available Background. Very few studies investigate the role of the autonomic nervous system in allergic rhinitis. In this study, we evaluated the autonomic nervous system in allergic rhinitis patients using heart rate variability (HRV analysis. Methods. Eleven patients with allergic rhinitis and 13 healthy controls, aged between 19 and 40 years old, were enrolled in the study. Diagnosis of allergic rhinitis was based on clinical history, symptoms, and positive Phadiatop test. Electrocardiographic recordings on the sitting and supine positions were obtained for HRV analysis. Results. In the supine position, there were no significant statistical differences in very-low-frequency power (VLF, ≤0.04 Hz, low-frequency power (LF, 0.04–0.15 Hz, high-frequency power (HF, 0.15–0.40 Hz, and the ratio of LF to HF (LF/HF between the patient and control groups. The mean RR intervals significantly increased, while LF% and LF/HF significantly decreased in the patient group in the sitting position. Moreover, mean RR intervals, LF, and LF/HF, which were significantly different between the two positions in the control group, did not show a significant change with the posture change in the patient group. Conclusion. These suggest that patients with allergic rhinitis may have poor sympathetic modulation in the sitting position. Autonomic dysfunction may therefore play a role in the pathophysiology of allergic rhinitis.
Full Text Available Heart rate variability (HRV is highly nonstationary, even if no perturbing influences can be identified during the recording of the data. The nonstationarity becomes more profound when HRV data are measured in intrinsically nonstationary environments, such as social stress. In general, HRV data measured in such situations are more difficult to analyze than those measured in constant environments. In this paper, we analyze HRV data measured during a social stress test using two multiscale approaches, the adaptive fractal analysis (AFA and scale-dependent Lyapunov exponent (SDLE, for the purpose of uncovering differences in HRV between chronic fatigue syndrome (CFS patients and their matched-controls. CFS is a debilitating, heterogeneous illness with no known biomarker. HRV has shown some promise recently as a non-invasive measure of subtle physiological disturbances and trauma that are otherwise difficult to assess. If the HRV in persons with CFS are significantly different from their healthy controls, then certain cardiac irregularities may constitute good candidate biomarkers for CFS. Our multiscale analyses show that there are notable differences in HRV between CFS and their matched controls before a social stress test, but these differences seem to diminish during the test. These analyses illustrate that the two employed multiscale approaches could be useful for the analysis of HRV measured in various environments, both stationary and nonstationary.
Lundby, C; Araoz, M; Van Hall, Gerrit
The purpose of the present study was to investigate the degree to which peak heart rate is reduced during exhaustive exercise in acute hypoxia. Five sea-level lowlanders performed maximal exercise at normobaric normoxia and at three different levels of hypobaric hypoxia (barometric pressures of 518......, 459, and 404 mmHg) in a hypobaric chamber and while breathing 9% O(2) in N(2). These conditions were equivalent to altitudes of 3300, 4300, 5300, and 6300 m above sea level, respectively. At 4300 m, maximal exercise was also repeated after 4 and 8 h. Peak heart rate (HR) decreased from 191 (182...
Karaşen, Rıza Murat; ÇİFTÇİ, Bülent; Acar, Baran; YALÇIN, Ahmet Arif; GÜVEN, Selma FIRAT
To demonstrate the effects of obstructive sleep apnea syndrome (OSAS) on baroregulatory function by using heart rate recovery (HRR) parameters. Materials and methods: Fifty-four moderate and severe OSAS patients were included in the study. HRR was defined as the difference in heart rate between peak exercise and 1 min later; a value of 18 beats/min was considered abnormal. OSAS patients were enrolled in the study as group 1 (normal HRR; n = 12) and group 2 (abnormal HRR, n = 42). Left ventr...
Miller, David A; Miller, Lisa A
In 1999, a highly publicized report from the Institute of Medicine identified major deficiencies in the United States health care system, which fueled the rapid growth of the modern patient safety movement. One of the greatest risks to patient safety in obstetrics is poor communication of electronic fetal heart rate monitoring findings. Standardization and elimination of unnecessary complexity are 2 of the cornerstones of improved patient safety. This article describes a standardized, simplified approach to the definition, interpretation, and management of electronic fetal heart rate monitoring that is evidence-based and reflects consensus in the literature. Copyright © 2012 Mosby, Inc. All rights reserved.
Zheng, Jiongxuan; Skufca, Joseph D; Bollt, Erik M
We use measured heart rate information (RR intervals) to develop a one-dimensional nonlinear map that describes short term deterministic behavior in the data. Our study suggests that there is a stochastic parameter with persistence which causes the heart rate and rhythm system to wander about a bifurcation point. We propose a modified circle map with a jump process noise term as a model which can qualitatively capture such this behavior of low dimensional transient determinism with occasional (stochastically defined) jumps from one deterministic system to another within a one parameter family of deterministic systems.
Mamalyga, M L
Heart rate variability parameters and the level of convulsive readiness during pentylenetetrazole-induced kindling in rats were analyzed using telemetric ECG and EEG monitoring. Analysis of ECG recorded over many days showed that heart rate variability was equally reduced after 7 and 27 days of kindling irrespective of the level of convulsive readiness. Reduced sympathovagal index after 7 days of kindling showed the compensatory character of changes. However, compensatory mechanisms cannot prevent high risk of life-threatening arrhythmias. High convulsive readiness after 27 days of kindling was accompanied by a shift of autonomic balance towards the increase in sympathetic tone, which may lead to decompensation and transition to a prenosological state.
Davidovic, Goran; Iric-Cupic, Violeta; Milanov, Srdjan; Dimitijevic, Aleksandra; Petrovic-Janicijevic, Mirjana
Many prospective studies established association between high heart rate and increased cardiovascular morbidity and mortality, independently of other risk factors. Heart rate over 80 beats per minute more often leads to atherosclerotic plaque disruption, the main step in developing acute coronary syndrome. Purpose was to investigate the incidence of higher heart rate levels in patients with anterior wall acute myocardial infarction with ST-segment elevation and the influence of heart rate on ...
Episodic and sustained increases in heart rate and mean arterial blood pressure can occur with recurring patterns of schedule-controlled behavior. Most previous studies were conducted under fixed-ratio schedules, which maintained a consistent high rate of responding that alternated with periods of no responding during times when the schedule was…
Full Text Available BackgroundCongenital heart diseases (CHD are the most common congenital anomaly in children and also the leading cause of mortality from congenital anomalies. Various factors including smoking, drinking alcohol and addiction play role in development of congenital heart diseases. This study was conducted with the aim of investigation of the prevalence of addiction in parents of children with congenital heart disease compared with healthy children.Materials and MethodsThis was a case-control study conducted on 320 children with congenital heart disease aged 6 months to 16 years and 320 healthy children as control group. Children referring to Ali Asghar hospital or who were hospitalized in Imam Ali Hospital were included in the study and their demographic characteristics and their parents were collected. Data were analyzed using SPSS 20.ResultsAverage age of diseased and healthy children was 4.08 ± 4.11 and 3.59 ± 2.36, respectively. The rate of addiction of father, mother and parents of children with congenital heart disease was higher than those of children in control group. The most common congenital heart disease was ventricular septal defect (VSD.ConclusionIn overall, this study showed addiction rate of parents in children with congenital heart disease was higher.
Daniel S Quintana
Full Text Available Heart rate variability (HRV refers to various methods of assessing the beat-to-beat variation in the heart over time, in order to draw inference on the outflow of the autonomic nervous system. Easy access to measuring HRV has led to a plethora of studies within emotion science and psychology assessing autonomic regulation, but significant caveats exist due to the complicated nature of HRV. Firstly, both breathing and blood pressure regulation have their own relationship to social, emotional and cognitive experiments – if this is the case are we observing heart rate changes as a consequence of breathing changes? Secondly, experiments often have poor internal and external controls. In this review we highlight the interrelationships between heart rate and respiration, as well as presenting recommendations for researchers to use when collecting data for HRV assessment. Namely, we highlight the superior utility of within-subjects designs along with the importance of establishing an appropriate baseline and monitoring respiration.
Malchaire, Jacques; d'AMBROSIO Alfano, Francesca Romana; Palella, Boris Igor
The assessment of harsh working conditions requires a correct evaluation of the metabolic rate. This paper revises the basis described in the ISO 8996 standard for the evaluation of the metabolic rate at a work station from the recording of the heart rate of a worker during a representative period of time. From a review of the literature, formulas different from those given in the standard are proposed to estimate the maximum working capacity, the maximum heart rate, the heart rate and the metabolic rate at rest and the relation (HR vs. M) at the basis of the estimation of the equivalent metabolic rate, as a function of the age, height and weight of the person. A Monte Carlo simulation is used to determine, from the approximations of these parameters and formulas, the imprecision of the estimated equivalent metabolic rate. The results show that the standard deviation of this estimate varies from 10 to 15%.
Five patients are reported, admitted to the hospital, with diseases predominantly of the cardio-vascular system. During the electrocardiographic examinations bundle branch block was established, depending on heart rate. It fluctuated within the physiological limits from 50 to 90/min. In three of the patients, the bundle branch block appeared with the quickening of the heart rate (tachycardia-depending bundle branch block) and in two of the patients--the bundle branch block appeared during the slowing down of the heart action and disappeared with its quickening (bradicardia-depending bundle branch block). A brief literature review is presented and attention is paid to the possible diagnostic errors and the treatment mode of those patients with cardiac tonic and antiarrhythmic medicaments.
Köbele, Ralf; Koschke, Mandy; Schulz, Steffen; Wagner, Gerd; Yeragani, Shravya; Ramachandraiah, Chaitra T; Voss, Andreas; Yeragani, Vikram K; Bär, Karl-Jürgen
Decreased cardiac vagal function is linked with increased cardiac mortality and depression is associated with decreased heart rate variability. We have previously shown that the Mood Induction Procedure (MIP) in healthy subjects alters pain perception and thalamic activity during pain perception. To study the effect of negative emotion on heart rate variability and complexity measures as well as on baroreceptor sensitivity, as these parameters reflect cardiac autonomic function. We studied 20 healthy female controls before and after neutral MIP and 20 healthy female subjects before and after negative MIP. We investigated measures of valence of mood, heart rate variability and complexity and the baroreceptor sensitivity index. While there was a significant difference in the valence of mood between the neutral and the negative effect condition, there were no significant differences in any of the heart rate or baroreceptor sensitivity measures between the two groups. Our findings did not show any significant influence of acute negative MIP on heart rate variability and complexity measures and baroreceptor sensitivity, even though depressive disorder and stress are associated with decreased heart rate variability. These findings are discussed in the context of clinical depression and anxiety and the increased risk for cardiac mortality. In contrast to the presented results here, we have previously shown that MIP in healthy subjects alters pain perception and thalamic activity.
Vora, Rathin; Zareba, Wojciech; Utell, Mark J; Pietropaoli, Anthony P; Chalupa, David; Little, Erika L; Oakes, David; Bausch, Jan; Wiltshire, Jelani; Frampton, Mark W
Diabetes may confer an increased risk for the cardiovascular health effects of particulate air pollution, but few human clinical studies of air pollution have included people with diabetes. Ultrafine particles (UFP, ≤100 nm in diameter) have been hypothesized to be an important component of particulate air pollution with regard to cardiovascular health effects. 17 never-smoker subjects 30-60 years of age, with stable type 2 diabetes but otherwise healthy, inhaled either filtered air (0-10 particles/cm3) or elemental carbon UFP (~107 particles/cm3, ~50 ug/m3, count median diameter 32 nm) by mouthpiece, for 2 hours at rest, in a double-blind, randomized, crossover study design. A digital 12-lead electrocardiogram (ECG) was recorded continuously for 48 hours, beginning 1 hour prior to exposure. Analysis of 5-minute segments of the ECG during quiet rest showed reduced high-frequency heart rate variability with UFP relative to air exposure (p = 0.014), paralleled by non-significant reductions in time-domain heart rate variability parameters. In the analysis of longer durations of the ECG, we found that UFP exposure increased the heart rate relative to air exposure. During the 21- to 45-hour interval after exposure, the average heart rate increased approximately 8 beats per minute with UFP, compared to 5 beats per minute with air (p = 0.045). There were no UFP effects on cardiac rhythm or repolarization. Inhalation of elemental carbon ultrafine particles alters heart rate and heart rate variability in people with type 2 diabetes. Our findings suggest that effects may occur and persist hours after a single 2-hour exposure.
Lu, Xi; Hui-Chan, Christina Wan-Ying; Tsang, William Wai-Nam
[Purpose] Exercise has been shown to improve cardiovascular fitness and cognitive function. Whether the inclusion of mind over exercise would increase parasympathetic control of the heart and brain activities more than general exercise at a similar intensity is not known. The aim of this study was to compare the effects of Tai Chi (mind-body exercise) versus arm ergometer cycling (body-focused exercise) on the heart rate variability and prefrontal oxygenation level. [Subjects and Methods] A Tai Chi master was invited to perform Tai Chi and arm ergometer cycling with similar exercise intensity on two separate days. Heart rate variability and prefrontal oxyhemoglobin levels were measured continuously by a RR recorder and near-infrared spectroscopy, respectively. [Results] During Tai Chi exercise, spectral analysis of heart rate variability demonstrated a higher high-frequency power as well as a lower low-frequency/high-frequency ratio than during ergometer cycling, suggesting increased parasympathetic and decreased sympathetic control of the heart. Also, prefrontal oxyhemoglobin and total hemoglobin levels were higher than those during arm ergometer exercise. [Conclusion] These findings suggest that increased parasympathetic control of the heart and prefrontal activities may be associated with Tai Chi practice. Having a "mind" component in Tai Chi could be more beneficial for older adults' cardiac health and cognitive function than body-focused ergometer cycling.
Cooney, Marie Therese
Elevated resting heart rate (RHR) is a known, independent cardiovascular (CV) risk factor, but is not included in risk estimation systems, including Systematic COronary Risk Evaluation (SCORE). We aimed to derive risk estimation systems including RHR as an extra variable and assess the value of this addition.
Knaven, Olga; Ganzevoort, Wessel; de Boer, Marjon; Wolf, Hans
Introduction: Several studies report a decrease of fetal heart rate (FHR) short-term variation (STV) after corticosteroids for improvement of fetal maturity and advice not to deliver a fetus for low STV within 2-3 days after corticosteroids. However, literature is not unanimous in this respect. This
Abstract. Background: Uncertainty often exists about the comparability of results obtained by different health risk indicator systems. Objectives: To compare two health risk indicator systems, i.e, allostatic load and heart rate variability (HRV). Additionally, to investigate the feasibility of inclusion of HRV indicators into allostatic ...
Incalzi, Raffaele Antonelli; Corsonello, Andrea; Trojano, Luigi; Pedone, Claudio; Acanfora, Domenico; Spada, Aldo; D'Addio, Gianni; Maestri, Roberto; Rengo, Franco; Rengo, Giuseppe
We studied 54 patients with hypoxemic chronic obstructive pulmonary disease (COPD). The Mini Mental State Examination and the Mental Deterioration Battery were used for neuropsychological assessment. Heart rate variability (HRV) was assessed based on 24-h Holter ECG recording. Mann-Whitney test was used to compare HRV parameters of patients…
Butruille, Laura; De Jonckheere, Julien; Jeanne, Mathieu; Tavernier, Benoît; Logier, Régis
An innovative technique based on the analysis of instantaneous heart rate variability helps to improve the prevention and management of pain and discomfort. Simple to implement, this non-invasive technique is based on the continuous recording of the electrocardiograph signal. Copyright Â© 2016 Elsevier Masson SAS. All rights reserved.
Börger, N.A.; Van der Meere, J.J.; Ronner, A.; Alberts, E.; Geuze, R.H.; Bogte, H
The major goal of the current study was to investigate the association between continuous performance tests (CPTs) and the heart rate variability (HRV) of attention deficit hyperactivity disorder (ADHD) children. The HRV, specifically the 0.10-Hz component, may be considered to be a
Full Text Available The aim of this study was to determine and learn the heart rate responses of basketball players in small-sided or modified games, in order to develop a more effective workout plan in the future. The study sample consisted of 19 basketball players from a National Championship Club, 12 of them in the U’14 category and the remaining 7 belonging to the U’16 category. Small-sided games were 3x3 and 4x4 with a duration of 4 minutes and an active break of 3 minutes. Significant differences (p<0.05 were found referring to the relations established between 3x3 without feedback and 3x3 with feedback in vigorous exercise; in 3x3 without feedback and 3x3 with feedback in moderate exercise; in 3x3 and 3x3 with average heart rate; in 4x4 and 4x4 with average heart rate and in 4x4 and 4x4 with average heart rate related to game categories.Keywords:
Jul 16, 2010 ... Power spectral analysis of the electrocardiographic R-R interval [heart rate variability: (HRV)] is a well known, non- invasive method for assessing autonomic nervous activity.1. Studies using HRV analysis during positive-pressure pneumoperitoneum (PPP) have demonstrated increased sympathetic ...
Background: Previous studies of autonomic nervous system activity through analysis of heart rate variability (HRV) have demonstrated increased sympathetic activity during positive-pressure pneumoperitoneum. We employed an online, continuous method for rapid HRV analysis (MemCalc™, Tarawa, Suwa Trust, Tokyo, ...
Haaksma, J; Brouwer, J; Dijk, WA; van den Berg, M; Takens, F; Dassen, WRM; Murray, A
Heart Rate Variability (HRV) may be measured using different measurement techniques. Almost all of these techniques deal with ectopic beats. Either these beats are excluded from the analysis or they are required. To access the functional character and easiness of use of several HRV techniques we
Kisilevsky, Barbara S.; Hains, Sylvia M. J.
A relationship between fetal heart rate (HR) and cognition is explored within the context of infant, child and adult studies where the association is well established. Lack of direct access to the fetus and maturational changes limit research paradigms and response measures for fetal studies. Nevertheless, neural regulation of HR shows a number of…
Elwess, Nancy L.; Vogt, F. Daniel
Conditions producing stress are present in all colleges and universities. In this paper we report on an investigation utilizing heart rate as an indicator of stress in students when participating in activities encountered in a college classroom or laboratory. The activities included presenting an oral report, taking an exam, and participating in a…
de Loos, Wolter Statius
Animai experiments may give information on the physiology of hormones under stress conditions. The model for the investigation of acute emotional stress in animals that has been chosen permits the study of heart rate in freely moving laboratory rats as a sensitive psychophysiological parameter, This
Amirian, Ilda; Toftegård Andersen, Lærke; Rosenberg, Jacob
BACKGROUND: Heart rate variability (HRV) has been used as a measure of stress and mental strain in surgeons. Low HRV has been associated with death and increased risk of cardiac events in the general population. The aim of this study was to clarify the effect of a 17-hour night shift on surgeons'...
Blood pressure and heart rate adjustment following acute Frenkel's ambulatory exercise in chronic hemiparetics stroke survivors: a comparative study. ... a pre, within and post-activity monitoring of stroke survivors while subjecting them to Frenkel's ambulatory activity. Keys words: cardiovascular, ambulatory activity, stroke ...
James, David V. B.; Munson, Steven C.; Maldonado-Martin, Sara; De Ste Croix, Mark B. A.
The purpose of the present study was to investigate the influence of two exercise intensities (moderate and severe) on heart rate variability (HRV) response in 16 runners 1 hr prior to (-1 hr) and at +1 hr, +24 hr, +48 hr, and +72 hr following each exercise session. Time domain indexes and a high frequency component showed a significant decrease…
Fisher, James P; Adlan, Ahmed M; Shantsila, Alena
We elucidated the autonomic mechanisms whereby heart rate (HR) is regulated by the muscle metaboreflex. Eight male participants (22 ± 3 years) performed three exercise protocols: (1) enhanced metaboreflex activation with partial flow restriction (bi-lateral thigh cuff inflation) during leg cycling...
To determine the appearance and development of embryonic heart rate a total of n = 317 Nigerian pregnant women were studied in the very early pregnancy from 23 – 56 days from the onset of last menstrual period (LMP). All pregnancies had a subsequent successful outcome. Transvaginal ultrasonography was ...
Ottesen, Johnny T.; Olufsen, Mette
are a consequence of the memory encapsulated by the models, and the nonlinearity gives rise to sigmoidal response curves. The nonlinear afferent baroreceptor models are coupled with an effector model, and the coupled model has been used to predict baroreceptor feedback regulation of heart rate during postural...
Background: Uncertainty often exists about the comparability of results obtained by different health risk indicator systems. Objectives: To compare two health risk indicator systems, i.e, allostatic load and heart rate variability (HRV). Additionally, to investigate the feasibility of inclusion of HRV indicators into allostatic load ...
The effect of exercise and lifestyle interventions on heart rate variability in students at risk of cardiovascular disease –A pilot study. ... African Journal for Physical Activity and Health Sciences ... Cardiovascular disease is a major public health concern and it can be modified by diet, exercise and health awareness. However ...
Christensen, Toke Folke; Randløv, Jette; Christensen, Leif Engmann
Introduction. Several studies show that hypoglycemia causes QT interval prolongation. The aim of this study was to investigate the effect of QT measurement methodology, heart rate correction, and insulin types during hypoglycemia. Methods. Ten adult subjects with type 1 diabetes had hypoglycemia ...
Sadeghi, Masoumeh; Gharipour, Mojgan; Nezafati, Pouya; Shafie, Davood; Aghababaei, Esmaeil; Sarrafzadegan, Nizal
The present study aimed to assess changes in resting and maximum heart rates as primary indicators of cardiac autonomic function in metabolic syndrome (MetS) patients and to determine their value for discriminating MetS from non-MetS. 468 participants were enrolled in this cross-sectional study and assessed according to the updated adult treatment panel III (ATP-III) definition of MetS. Resting and maximum heart rates were recorded following the Bruce protocol during an exercise. A receiver operating characteristic (ROC) curve was used to identify the best cutoff point for discriminating MetS from the non-MetS state. 194 participants (41.5%) were diagnosed as MetS. The mean resting heart rate (RHR) was not statistically different between the two groups (P=0.078). However, the mean maximum heart (MHR) rate was considerably higher in participants with MetS (142.37±14.84 beats per min) compared to the non-MetS group (134.62±21.63 beats per min) (Pgroup, the MHR was positively correlated with the serum triglyceride level (β=0.185, P=0.033) and was inversely associated with age (β=-0.469, Page. Moreover, MHR can be used as a suspicious indicator for identifying MetS.
In this thesis a renewed monitoring technique for fetal heart rate (FHR) and uterine activity has been investigated. Through non-invasive measurements of electrical signals as recorded from the maternal abdomen, both the fetal-electrocardiogram (fECG) and uterine electrohysterogram (EHG) can be
Procedure. This study is a comparative observational study of the pre/post test influence of Frenkel's ambulatory activity on heart rate and blood pressure in hemiparetic stroke survivors undergoing rehabilitation. The study was conducted in the gymnasium of the Department of Physiotherapy, Aminu Kano Teaching Hospital.
Castro-Sepulveda, Mauricio; Cerda-Kohler, Hugo; Pérez-Luco, Cristian; Monsalves, Matías; Andrade, David Cristobal; Zbinden-Foncea, Herman; Báez-San Martín, Eduardo; Ramírez-Campillo, Rodrigo
Heart rate variability and resting metabolic rate are commonly to assess athlete's physiological status and energy requirements. Exercise-induced dehydration can reach up to 5% of body mass per hour. Consequently, dehydration may have a profound physiological effect on human's homeostasis. To compare the effects of dehydration and rehydration after exercise on heart rate variability and resting metabolic rate in college athletes. 14 college athletes were divided into a dehydration group (n=7) and a rehydration group (n=7), both submitted to basal (T1) heart rate variability and resting metabolic rate measurements. After basal measurements both groups were actively dehydrated (-3.4 ± 0.4% of body mass for both groups). Afterwards, dehydration group rested, while rehydration group receive a fluid intake (during a 3 h period) equivalent to 150% of body mass loss achieved during active dehydration. Four hours after active dehydration heart rate variability and resting metabolic rate were re-assessed (T2). At T2 both rehydration group (+13%) and dehydration group (+30%) achieve a significant (phydration state before resting metabolic rate and heart rate variability assessment. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.
de Hartog, J.J.|info:eu-repo/dai/nl/288354850; Lanki, T.; Timonen, K.L.; Hoek, G.|info:eu-repo/dai/nl/069553475; Janssen, N.A.H.; Ibald-Mulli, A.; Peters, A.; Heinrich, J.; Tarkiainen, T.; Van Grieken, R.; van Wijnen, J.H.; Brunekreef, B.|info:eu-repo/dai/nl/067548180; Pekkanen, J.
BACKGROUND: It has been hypothesized that ambient particulate air pollution is able to modify the autonomic nervous control of the heart, measured as heart rate variability (HRV). Previously we reported heterogeneous associations between particulate matter with aerodynamic diameter <2.5 microm
TUININGA, YS; VANVELDHUISEN, DJ; CRIJNS, HJGM; VANDENBROEK, SAJ; BROUWER, J; HAAKSMA, J; MANINTVELD, AJ; LIE, KI
Ventricular arrhythmias and disturbed autonomic control, as reflected by abnormal heart rate variability (HRV), are related to hemodynamic impairment in chronic heart failure (CHF). We investigated the effects of orally (p.o.) administered isomazole, a new phosphodiesterase (PDE) inhibitor with
Licht, Carmilla M. M.; de Geus, Eco J. C.; van Dyck, Richard; Penninx, Brenda W. J. H.
Objective: To determine whether patients with different types of anxiety disorder (panic disorder, social phobia, generalized anxiety disorder) have higher heart rate and lower heart rate variability compared with healthy controls in a sample that was sufficiently powered to examine the confounding
Dyavanapalli, Jhansi; Jameson, Heather; Dergacheva, Olga; Jain, Vivek; Alhusayyen, Mona; Mendelowitz, David
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.
Maureen A.J.M. van Eijnatten
Full Text Available The non-invasively measured Initial Systolic Time Interval (ISTI reflects a time difference between the electrical and pumping activity of the heart and depends on cardiac preload, afterload, autonomic nervous control and training level. However, the duration of the ISTI has not yet been compared to other time markers of the heart cycle. The present study gauges the duration of the ISTI by comparing the end point of this interval, the C-point, with heart cycle markers obtained by echocardiography. The heart rate of 16 healthy subjects was varied by means of an exercise stimulus. It was found that the C-point, and therefore the end point of ISTI, occurred around the moment of the maximum diameter of the aortic arch in all subjects and at all heart rates. However, while the time difference between the opening of the aortic valves and the maximum diameter of the aortic arch decreased significantly with decreasing RR-interval, the time difference with respect to the moment of the C-point remained constant within the subjects. This means that the shortening of the ISTI with increasing heart rate in response to an exercise stimulus was caused by a shortening of the pre-ejection period (PEP. It is concluded that the ISTI can be used as a non-invasive parameter indicating the time difference between the electrical and mechanical pumping activity of the heart, both inside and outside the clinic.
Medow, Marvin S; Merchant, Sana; Suggs, Melissa; Terilli, Courtney; O'Donnell-Smith, Breige; Stewart, Julian M
Recurrent postural vasovagal syncope (VVS) is caused by transient cerebral hypoperfusion from episodic hypotension and bradycardia; diagnosis is made by medical history. VVS contrasts with postural tachycardia syndrome (POTS), defined by chronic daily symptoms of orthostatic intolerance with excessive upright tachycardia without hypotension. POTS has recently been conflated with VVS when excessive tachycardia is succeeded by hypotension during tilt testing. We hypothesize that excessive tachycardia preceding hypotension and bradycardia is part of the vasovagal response during tilt testing of patients with VVS. We prospectively performed head-up tilt (HUT) testing on patients with recurrent VVS (n = 47, 17.9 ± 1.1 y), who fainted at least 3 times within the last year, and control subjects (n = 15, 17.1 ± 1.0 y), from age and BMI-matched volunteers and measured blood pressure, heart rate (HR), cardiac output, total peripheral resistance, and end tidal carbon dioxide. Baseline parameters were the same in both groups. HR (supine versus 5 and 10 minutes HUT) significantly increased in control (65 ± 2.6 vs 83 ± 3.6 vs 85 ± 3.7, P < .001) and patients with VVS (69 ± 1.6 vs 103 ± 2.3 vs 109 ± 2.4, P < .001). HUT in controls maximally increased HR by 20.3 ± 2.9 beats per minute; the increase in patients with VVS of 39.8 ± 2.1 beats per minute was significantly greater (P < .001). An increase in HR of ≥40 beats per minute by 5 and 10 minutes or before faint with HUT, occurred in 26% and 44% of patients with VVS, respectively, but not in controls. Orthostasis in VVS is accompanied by large increases in HR that should not be construed as POTS. Copyright © 2017 by the American Academy of Pediatrics.
Shaffer, Fred; McCraty, Rollin; Zerr, Christopher L
Heart rate variability (HRV), the change in the time intervals between adjacent heartbeats, is an emergent property of interdependent regulatory systems that operate on different time scales to adapt to challenges and achieve optimal performance. This article briefly reviews neural regulation of the heart, and its basic anatomy, the cardiac cycle, and the sinoatrial and atrioventricular pacemakers. The cardiovascular regulation center in the medulla integrates sensory information and input from higher brain centers, and afferent cardiovascular system inputs to adjust heart rate and blood pressure via sympathetic and parasympathetic efferent pathways. This article reviews sympathetic and parasympathetic influences on the heart, and examines the interpretation of HRV and the association between reduced HRV, risk of disease and mortality, and the loss of regulatory capacity. This article also discusses the intrinsic cardiac nervous system and the heart-brain connection, through which afferent information can influence activity in the subcortical and frontocortical areas, and motor cortex. It also considers new perspectives on the putative underlying physiological mechanisms and properties of the ultra-low-frequency (ULF), very-low-frequency (VLF), low-frequency (LF), and high-frequency (HF) bands. Additionally, it reviews the most common time and frequency domain measurements as well as standardized data collection protocols. In its final section, this article integrates Porges' polyvagal theory, Thayer and colleagues' neurovisceral integration model, Lehrer et al.'s resonance frequency model, and the Institute of HeartMath's coherence model. The authors conclude that a coherent heart is not a metronome because its rhythms are characterized by both complexity and stability over longer time scales. Future research should expand understanding of how the heart and its intrinsic nervous system influence the brain.
Diego Giulliano Destro Christofaro
Full Text Available Abstract Background: High resting heart rate is considered an important factor for increasing mortality chance in adults. However, it remains unclear whether the observed associations would remain after adjustment for confounders in adolescents. Objectives: To analyze the relationship between resting heart rate, blood pressure and pulse pressure in adolescents of both sexes. Methods: A cross-sectional study with 1231 adolescents (716 girls and 515 boys aged 14-17 years. Heart rate, blood pressure and pulse pressure were evaluated using an oscillometric blood pressure device, validated for this population. Weight and height were measured with an electronic scale and a stadiometer, respectively, and waist circumference with a non-elastic tape. Multivariate analysis using linear regression investigated the relationship between resting heart rate and blood pressure and pulse pressure in boys and girls, controlling for general and abdominal obesity. Results: Higher resting heart rate values were observed in girls (80.1 ± 11.0 beats/min compared to boys (75.9 ± 12.7 beats/min (p ≤ 0.001. Resting heart rate was associated with systolic blood pressure in boys (Beta = 0.15 [0.04; 0.26] and girls (Beta = 0.24 [0.16; 0.33], with diastolic blood pressure in boys (Beta = 0.50 [0.37; 0.64] and girls (Beta = 0.41 [0.30; 0.53], and with pulse pressure in boys (Beta = -0.16 [-0.27; -0.04]. Conclusions: This study demonstrated a relationship between elevated resting heart rate and increased systolic and diastolic blood pressure in both sexes and pulse pressure in boys even after controlling for potential confounders, such as general and abdominal obesity.
Pittig, Andre; Arch, Joanna J; Lam, Chi W R; Craske, Michelle G
It remains unclear if diminished high frequency heart rate variability (HF-HRV) can be found across anxiety disorders. HF-HRV and heart rate (HR) were examined in panic (PD), generalized anxiety (GAD), social anxiety (SAD), and obsessive-compulsive disorder (OCD) relative to healthy controls at baseline and during anxiety stressors. All disorders evidenced diminished baseline HF-HRV relative to controls. Baseline HRV differences were maintained throughout relaxation. For hyperventilation, PD and GAD demonstrated greater HR than controls. Psychotropic medication did not account for HF-HRV differences except in OCD. Age and sex evidenced multiple main effects. Findings suggest that low baseline HF-HRV represents a common index for inhibitory deficits across PD, GAD, and SAD, which is consistent with the notion of autonomic inflexibility in anxiety disorders. Elevated HR responses to hyperventilation, however, are specific to PD and GAD. Copyright © 2012 Elsevier B.V. All rights reserved.
Ramos-Bonilla, Juan P; Breysse, Patrick N; Dominici, Francesca; Geyh, Alison; Tankersley, Clarke G
Heart rate alterations associated with exposure to particulate matter (PM) and gaseous pollutants have been observed in epidemiological studies and animal experiments. Nevertheless, the time-lag of these associations is still unclear. Determine the association at different time-lags between the complex mixture of ambient concentrations of PM, carbon monoxide (CO), and nitrogen dioxide (NO(2)), and markers of cardiac function in a model of aged mice. AKR/J inbred mice were exposed to ambient air, 6 h daily for 40 weekdays. During this period, the animals' electrocardiogram (ECG), deep body temperature (Tdb), and body weight (BW) were registered, and concentrations of PM, CO, NO(2), as well as air temperature and relative humidity (RH) were measured. Data analysis included random effects models with lagged covariate methods. CO was significantly associated with declines in heart rate (HR) and heart rate variability (HRV), PM was significantly associated with declines in HRV and BW, and NO(2) was significantly associated with declines in HR. Some significant associations occurred in the same day (PM and HRV, PM and BW, CO and HR), whereas others were delayed by 1 to 3 days (CO and HR, CO and HRV, NO(2) and HR, PM and HRV). Finding significant declines in heart function in aged mice associated with the combined effects of air pollutants at ambient concentrations and at different time-lags is of great importance to public health. These results further implicate the potential short term and delayed effects of air pollution on HR alterations.
Davidovic, Goran; Iric-Cupic, Violeta; Milanov, Srdjan; Dimitijevic, Aleksandra; Petrovic-Janicijevic, Mirjana
Many prospective studies established association between high heart rate and increased cardiovascular morbidity and mortality, independently of other risk factors. Heart rate over 80 beats per minute more often leads to atherosclerotic plaque disruption, the main step in developing acute coronary syndrome. Purpose was to investigate the incidence of higher heart rate levels in patients with anterior wall acute myocardial infarction with ST-segment elevation and the influence of heart rate on mortality. Research included 140 patients with anterior wall acute myocardial infarction with ST-segment elevation treated in Coronary Unit, Clinical Center Kragujevac in the period from January 2001-June 2006. Heart rate was calculated as the mean value of baseline and heart rate in the first 30 minutes after admission. Other risk factors were also followed to determine their connection with elevated heart rate. Results showed that the majority of patients survived (over 70%). In a total number of patients, more than 75% had a heart rate levels greater than 80 beats per minute. There was a significant difference in heart rate on addmision between survivors and patients who died, with a greater levels in patients with fatal outcome. Both, univariate and multivariate regression analysis singled out heart rate greater than 80 beats per minute as independent mortality predictor in these patients. Heart rate greater than 80 beats per minute is a major, independent risk factor for morbidity and important predictor of mortality in patients with acute myocardial infarction.
Lebech, Anne-Mette; Kristoffersen, Ulrik Sloth; Mehlsen, Jesper
guidelines and data reported as median (interquartile range). RESULTS: The resting heart rate was higher in HIV patients compared with controls [69 (62-74) versus 57 (52-60); Pstandard deviation of normal-to-normal (SONN) was lower in the HIV group compared with the controls...... of healthy volunteers (n = 12) were included. All were non-smokers, non-diabetic and had never received medication for dyslipidaemia or hypertension. Following a 10 min resting period a 5 min ECG recording was performed. Heart rate variability (HRV) analysis was performed in accordance with current...... [294 (161-602) versus 946 (711-1668) ms(2); Prate and decreased short-term heart rate variability indicating parasympathetic...
Steer, Philip J
Electronic fetal heart rate monitoring (EFHRM) has revolutionised our understanding of the function of the cardiovascular system of the fetus during labour, and how the fetus responds to hypoxia. However, although it is a sensitive technique for the detection of hypoxia during labour, it is relatively non-specific for detecting the development of acidosis. Moreover, it is highly dependent on accurate interpretation of fetal heart rate (FHR) patterns, which has been shown to be commonly of a low standard in everyday clinical practice. Use of EFHRM has probably reduced the incidence of birth asphyxia, but it has also contributed to the rise in the caesarean section rate. Ancillary techniques, such as pulse oximetry, have not proved useful, although ST-segment analysis of the ECG waveform shows some promise. Computerised expert systems for the analysis of FHR patterns may be more successful at avoiding poor outcomes.
Si, Junfeng; Zhou, Lingling; Huang, Xiaoling; Bian, Chunhua
In this study, we applied generalized autoregressive conditional heteroskedasticity (GARCH) model to conditional fluctuation characteristics of heart rate variation (HRV) series (congestive heart failure, Normal), with all the data from PhysioNet ECG database. Research results proved the existence of condition fluctuation characteristic in the series of changing rate of HRV. In the GARCH model family, threshold GARCH (1,1)(TGARCH (1,1)) model performs best in fitting changing rate of HRV. Although the structure of ARCH (1) model is simple, its error is the closest to that of TGARCH (1, 1) model. The results also showed that the difference was obvious between disease group and normal group. All these results provide a new method to the research and clinical application of HRV.
Comparison of the Effects of Two Auditory Methods by Mother and Fetus on the Results of Non-Stress Test (Baseline Fetal Heart Rate and Number of Accelerations in Pregnant Women: A Randomized Controlled Trial
Full Text Available Objective: To compare the effects of two auditory methods by mother and fetus on the results of NST in 2011-2012.Materials and methods: In this single-blind clinical trial, 213 pregnant women with gestational age of 37-41 weeks who had no pregnancy complications were randomly divided into 3 groups (auditory intervention for mother, auditory intervention for fetus, and control each containing 71 subjects. In the intervention groups, music was played through the second 10 minutes of NST. The three groups were compared regarding baseline fetal heart rate and number of accelerations in the first and second 10 minutes of NST. The data were analyzed using one-way ANOVA, Kruskal-Wallis, and paired T-test.Results: The results showed no significant difference among the three groups regarding baseline fetal heart rate in the first (p = 0.945 and second (p = 0.763 10 minutes. However, a significant difference was found among the three groups concerning the number of accelerations in the second 10 minutes. Also, a significant difference was observed in the number of accelerations in the auditory intervention for mother (p = 0.013 and auditory intervention for fetus groups (p < 0.001. The difference between the number of accelerations in the first and second 10 minutes was also statistically significant (p = 0.002.Conclusion: Music intervention was effective in the number of accelerations which is the indicator of fetal health. Yet, further studies are required to be conducted on the issue.
Wells, Ruth; Outhred, Tim; Heathers, James A J; Quintana, Daniel S; Kemp, Andrew H
Musical performance is a skilled activity performed under intense pressure, thus is often a profound source of anxiety. In other contexts, anxiety and its concomitant symptoms of sympathetic nervous system arousal have been successfully ameliorated with HRV biofeedback (HRV BF), a technique involving slow breathing which augments autonomic and emotional regulatory capacity. This randomised-controlled study explored the impact of a single 30-minute session of HRV BF on anxiety in response to a highly stressful music performance. A total of 46 trained musicians participated in this study and were randomly allocated to a slow breathing with or without biofeedback or no-treatment control group. A 3 Group×2 Time mixed experimental design was employed to compare the effect of group before and after intervention on performance anxiety (STAI-S) and frequency domain measures of HRV. Slow breathing groups (n=30) showed significantly greater improvements in high frequency (HF) and LF/HF ratio measures of HRV relative to control (n=15) during 5 minute recordings of performance anticipation following the intervention (effect size: η(2) =0.122 and η(2) =0.116, respectively). The addition of biofeedback to a slow breathing protocol did not produce differential results. While intervention groups did not exhibit an overall reduction in self-reported anxiety, participants with high baseline anxiety who received the intervention (n=15) displayed greater reductions in self-reported state anxiety relative to those in the control condition (n=7) (r=0.379). These findings indicate that a single session of slow breathing, regardless of biofeedback, is sufficient for controlling physiological arousal in anticipation of psychosocial stress associated with music performance and that slow breathing is particularly helpful for musicians with high levels of anxiety. Future research is needed to further examine the effects of HRV BF as a low-cost, non-pharmacological treatment for music
Full Text Available BACKGROUND: Musical performance is a skilled activity performed under intense pressure, thus is often a profound source of anxiety. In other contexts, anxiety and its concomitant symptoms of sympathetic nervous system arousal have been successfully ameliorated with HRV biofeedback (HRV BF, a technique involving slow breathing which augments autonomic and emotional regulatory capacity. OBJECTIVE: This randomised-controlled study explored the impact of a single 30-minute session of HRV BF on anxiety in response to a highly stressful music performance. METHODS: A total of 46 trained musicians participated in this study and were randomly allocated to a slow breathing with or without biofeedback or no-treatment control group. A 3 Group×2 Time mixed experimental design was employed to compare the effect of group before and after intervention on performance anxiety (STAI-S and frequency domain measures of HRV. RESULTS: Slow breathing groups (n=30 showed significantly greater improvements in high frequency (HF and LF/HF ratio measures of HRV relative to control (n=15 during 5 minute recordings of performance anticipation following the intervention (effect size: η(2 =0.122 and η(2 =0.116, respectively. The addition of biofeedback to a slow breathing protocol did not produce differential results. While intervention groups did not exhibit an overall reduction in self-reported anxiety, participants with high baseline anxiety who received the intervention (n=15 displayed greater reductions in self-reported state anxiety relative to those in the control condition (n=7 (r=0.379. CONCLUSIONS: These findings indicate that a single session of slow breathing, regardless of biofeedback, is sufficient for controlling physiological arousal in anticipation of psychosocial stress associated with music performance and that slow breathing is particularly helpful for musicians with high levels of anxiety. Future research is needed to further examine the effects of
Oh, Myung Ok; Kim, Young Jeoum; Baek, Cho Hee; Kim, Ju Hee; Park, No Mi; Yu, Mi Jeong; Song, Han Sol
The purpose of this cross-over experimental study was to examine effects of music intervention on maternal anxiety, fetal heart rate pattern and testing time during non-stress tests (NST) for antenatal fetal assessment. Sixty pregnant women within 28 to 40 gestational weeks were randomly assigned to either the experimental group (n=30) or control group (n=30). Music intervention was provided to pregnant women in the experimental group during NST. Degree of maternal anxiety and fetal heart rate pattern were our primary outcomes. State-trait anxiety inventory, blood pressure, pulse rate, and changes in peripheral skin temperature were assessed to determine the degree of maternal anxiety. Baseline fetal heart rate, frequency of acceleration in fetal heart rate, fetal movement test and testing time for reactive NST were assessed to measure the fetal heart rate pattern. The experimental group showed significantly lower scores in state anxiety than the control group. There were no significant differences in systolic blood pressure and pulse rate between the two groups. Baseline fetal heart rate was significantly lower in the experimental group than in the control group. Frequency of acceleration in fetal heart rate was significantly increased in the experimental group compared to the control group. There were no significant differences in fetal movement and testing time for reactive NST between the two groups. Present results suggest that music intervention could be an effective nursing intervention for alel viating anxiety during non-stress test.
Kolasińska-Kloch, Władysława; Furgała, Agata; Banach, Tomasz; Laskiewicz, Janusz; Thor, Piotr J
Abnormalities of autonomic nervous system function (ANS) exist in patients with hypertension and have been considered as one of the important factors in developing of essential hypertension. However the information about the effect of antihypertensive treatment (angiotensin-converting enzyme inhibitors--ACEI) on cardiac ANS activity is scarce. The main aim of our study was to evaluate circadian heart rate variability changes in primary hypertension treated with ACE inhibitors. Fourteen patients with essential hypertension with night/day differences of mean blood pressure of more than 10% (dippers) aged 26 to 61 years (mean 52.9 +/- 9.2) and 14 healthy volunteers, 14 healthy volunteers were recruited and matched for age and gender. Ambulatory 24 hour arterial blood pressure measurement using HolCARD (Aspel, Poland) recorder with simultaneous ECG monitoring using the Mediarc-Premier IV Holter Monitoring System (DRG-International) undertaken in both groups of patients. The hypertensive patients were tested before and after one year of the enalapril treatment. The HRV analysis was performed according to a standard Fast Fourier Transformation (FFT). The time and spectral analysis parameters were compared within the examined groups of patients during day and night. The results obtained in the control group showed the great circadian fluctuations in sympathetic and parasympathetic activity. A simultaneous circadian HRV evaluation showed also significant increases in night RMSSD, TP, VLF, LF and HF mean values (p < 0.05) with significantly decreased night LF/HF ratio (p < 0.05) in comparison to the day time recordings. After one year of ACE inhibitors treatment, we noted the following circadian changes: Significant increase of RMSSD, pNN50 (p < 0.05), TP, VLF, LF and HF (p < 0.05) parameters with non-significant increases in LF/HF ratio during night recording. A comparison between daily HRV parameters, before and after 1 year of ACEI treatment, presented significant
Shcheslavskaya, Olga V.; Burg, Matthew M.; McKinley, Paula S.; Schwartz, Joseph E.; Gerin, William; Ryff, Carol D.; Weinstein, Maxine; Seeman, Teresa E.; Sloan, Richard P.
Objectives To investigate the effect of age on heart rate recovery (HRR) from cognitive challenge. Background Aging is an independent risk factor for the development of cardiovascular disease. HRR from exercise is an established predictor of cardiac morbidity and mortality, and evidence suggests that HRR from cognitive challenge is predictive of cardiac morbidity as well. Aging is associated with delayed HRR from exercise stress, but little is known about the effect of aging on HRR from psychological stress. We tested the hypothesis that age would be related to delayed HRR from psychological stress. Methods HRR following exposure to cognitive challenge (mental arithmetic and Stroop) was investigated in a sample of 436 participants aged 35–84 in MIDUS II, a national study of health and well-being. HRR was measured as (1) the amount of change from the stress level; (2) time to recover; and (3) the area under the curve (AUC). The analyses were controlled for medical comorbidities and medications that influence HR, such as BMI, smoking, sex, menopausal status, and amount of physical activity/exercise. Results There was no effect for age on HRR as evaluated by all three recovery assessment methods. Conclusions Contrary to expectation and in contrast to findings concerning HRR from exercise, HRR from cognitive challenge was preserved with age. These findings require further inquiry into differential mechanism(s) underlying HRR from psychological vs. exercise stress, including any role for improved emotion regulation with greater age. PMID:20028831
Full Text Available Sleep is divided into two main sleep stages: 1 non-rapid eye movement sleep (non-REMS, characterized among others by reduced global brain activity; and 2 rapid eye movement sleep (REMS, characterized by global brain activity similar to that of wakefulness. Results of heart rate variability (HRV analysis, which is widely used to explore autonomic modulation, have revealed higher parasympathetic tone during normal non-REMS and a shift toward sympathetic predominance during normal REMS. Moreover, HRV analysis combined with brain imaging has identified close connectivity between autonomic cardiac modulation and activity in brain areas such as the amygdala and insular cortex during REMS, but no connectivity between brain and cardiac activity during non-REMS. There is also some evidence for an association between HRV and dream intensity and emotionality. Following some technical considerations, this review addresses how brain activity during sleep contributes to changes in autonomic cardiac activity, organized into three parts: 1 the knowledge on autonomic cardiac control, 2 differences in brain and autonomic activity between non-REMS and REMS, and 3 the potential of HRV analysis to explore the sleeping brain, and the implications for psychiatric disorders.
Ashdown, Amanda J; Scerbo, Mark W; Belfore, Lee A; Davis, Stephen S; Abuhamad, Alfred Z
Objective This study examined the ability of clinicians to correctly categorize images of fetal heart rate (FHR) variability with and without the use of exemplars. Study Design A sample of 33 labor and delivery clinicians inspected static FHR images and categorized them into one of four categories defined by the National Institute of Child Health and Human Development (NICHD) based on the amount of variability within absent, minimal, moderate, or marked ranges. Participants took part in three conditions: two in which they used exemplars representing FHR variability near the center or near the boundaries of each range, and a third control condition with no exemplars. The data gathered from clinicians were compared with those from a previous study using novices. Results Clinicians correctly categorized more images when the FHR variability fell near the center rather than the boundaries of each range, F (1,32) = 71.69, p visual aids to improve judgments about FHR variability and potentially enhance safety in labor and delivery.
Alp, A; Ozdogan, O; Guloglu, C C; Turker, M; Atabay, B
Iron cardiomyopathy remains the major cause of death in β-thalassaemia major. Excessive iron loading could lead to cardiac dysfunction and arrhythmias. Reduced heart rate variability is associated with a higher risk of arrhythmia and sudden death after myocardial infarction and heart failure. Previous data have reported on reduced heart rate variability in patients with marked cardiac iron accumulation. In this study, we compared heart rate variability among β-thalassaemia major (TM) patients with or without cardiac siderosis. Out of 70 β-thalassaemia major patients with preserved ejection fractions, 38 patients with cardiac T2* magnetic resonance imaging assessment were included in our study. Time domain heart rate variability parameters were analysed from 24-hour recorded electrocardiograms and were compared with the control group. The mean T2* magnetic resonance imaging value was 22.9 ± 13.3 (4.7-47.5). In 21 patients with β-thalassaemia major, the T2* magnetic resonance imaging values were greater than 20 ms and these patients were considered to be in the early stage of the disease. When we compare these patients with control subjects, the standard deviation of all NN intervals was still significantly lower (133.0 ± 32.2 versus 162.8 ± 32.9, p = 0.001) in β-thalassaemia major patients despite normal T2* magnetic resonance imaging values. On the contrary, the standard deviation of all NN intervals was not correlated with haemoglobin levels in these patients (p > 0.05). Heart rate variability parameters were reduced even in β-thalassaemia major patients without evident cardiac siderosis, as specified by magnetic resonance imaging data. The results of this study show that reduction of heart rate variability may start before cardiac iron loading is demonstrated by T2* magnetic resonance imaging in β-thalassaemia major.
Full Text Available From the 1990s, extensive research was started on the physiological aspects of individual traits in animals. Previous research has established two extreme (proactive and reactive coping styles in several animal species, but the means of reactivity with the autonomic nervous system (ANS activity has not yet been investigated in cattle. The aim of this study was the characterization of cardiac autonomic activity under different conditions in cows with different individual characteristics. For this purpose, we investigated heart rate and ANS-related heart rate variability (HRV parameters of dairy cows (N = 282 on smaller- and larger-scale farms grouped by (1 temperament and (2 behavioural reactivity to humans (BRH. Animals with high BRH scores were defined as impulsive, while animals with low BRH scores were defined as reserved. Cardiac parameters were calculated for undisturbed lying (baseline and for milking bouts, the latter with the presence of an unfamiliar person (stressful situation. Sympathetic tone was higher, while vagal activity was lower in temperamental cows than in calm animals during rest both on smaller- and larger-scale farms. During milking, HRV parameters were indicative of a higher sympathetic and a lower vagal activity of temperamental cows as compared to calm ones in farms of both sizes. Basal heart rate did not differ between BRH groups either on smaller- or larger-scale farms. Differences between basal ANS activity of impulsive and reserved cows reflected a higher resting vagal and lower sympathetic activity of reserved animals compared to impulsive ones both on smaller- and larger-scale farms. There was no difference either in heart rate or in HRV parameters between groups during milking neither in smaller- nor in larger-scale farms. These two groupings allowed to draw possible parallels between personality and cardiac autonomic activity during both rest and milking in dairy cows. Heart rate and HRV seem to be useful for
Hamelmann, Paul; Vullings, Rik; Schmitt, Lars; Kolen, Alexander F; Mischi, Massimo; van Laar, Judith O E H; Bergmans, Jan W M
Doppler ultrasound (US) is the most commonly applied method to measure the fetal heart rate (fHR). When the fetal heart is not properly located within the ultrasonic beam, fHR measurements often fail. As a consequence, clinical staff need to reposition the US transducer on the maternal abdomen, which can be a time consuming and tedious task. In this article, a method is presented to aid clinicians with the positioning of the US transducer to produce robust fHR measurements. A maximum likelihood estimation (MLE) algorithm is developed, which provides information on fetal heart location using the power of the Doppler signals received in the individual elements of a standard US transducer for fHR recordings. The performance of the algorithm is evaluated with simulations and in vitro experiments performed on a beating-heart setup. Both the experiments and the simulations show that the heart location can be accurately determined with an error of less than 7 mm within the measurement volume of the employed US transducer. The results show that the developed algorithm can be used to provide accurate feedback on fetal heart location for improved positioning of the US transducer, which may lead to improved measurements of the fHR.
Bourassa, Kyle J; Allen, John J B; Mehl, Matthias R; Sbarra, David A
Divorce is a common stressor that is associated with increased risk for poor long-term physical and mental health. Using an experimental design, the current study examined the impact of expressive writing (EW) on average heart rate (HR), HR variability (HRV), and blood pressure (BP) 7.5 months later. Participants from a community sample of recently separated adults (N = 109) were assigned to one of three conditions: traditional EW, narrative EW, or a control writing condition, and were assessed three times for an average of 7.5 months. Each study visit included 27 minutes of physiological assessment; the primary outcomes at each assessment were mean-level HR, HRV, BP scores averaged across six different tasks. Participants in the traditional EW condition did not significantly differ from control participants in their later HR, HRV, or BP. However, relative to control participants, those in the narrative EW condition had significantly lower HR (B = -3.41, 95% confidence interval = -5.76 to -1.06, p = .004) and higher HRV 7.5 months later (B = 0.41, 95% confidence interval = 0.16 to 0.74, p = .001). When comparing narrative EW participants to those in the traditional EW and control writing as a single group, these effects remained and were moderately sized, Cohen d values of -0.61 and 0.60, respectively, and durable across all task conditions when analyzed in independent models. The writing condition groups did not differ in their later BP. Narrative EW decreased HR and increased HRV after marital separation but did not affect BP. We discuss the possible disconnect between psychology and physiology in response to EW, as well as possible future clinical applications after marital separation.
Hajdusek, Pavel; Kotrc, Martin; Kautzner, Josef; Melenovsky, Vojtech; Benesova, Eva; Jarolim, Petr; Benes, Jan
The dynamics of the sinus node response to exercise is linked to functional capacity and outcome in heart failure (HF). The goal of the work was to analyze determinants and impacts of cardio-acceleration, described by the concept of metabolic-chronotropic relation (MCR) and of cardio-deceleration, described by heart rate recovery (HRR). A cohort of 25 healthy controls and 78 patients with advanced systolic HF and optimized medical and/or device therapy (97% receiving beta-blockers, 54% ICD) underwent maximal cardiopulmonary exercise test and were prospectively followed. HF patients had impaired exercise performance compared with controls (pVO2 15±4 vs. 29±7ml.kg-1.min-1, pslope (0.54±0.24 vs. 0.90±0.15, pslope was inversely associated with beta-blocker dose (r=-0.24), NYHA class (r=-0.28) and HF duration (r=-0.25), whereas HRR with estimated glomerular filtration rate (eGFR, r=0.39), age (r=-0.28) and BMI (r=-0.31, all pslope (p=0.02) but not HRR (p=0.19). MCR slope (but not HRR) was a significant outcome predictor (p=0.02 for Cox unadjusted model) even after adjustment for LVEF, serum natrium, systolic blood pressure, eGFR and NT-proBNP (p=0.04). MCR slope is associated with different clinical variables than HRR. Compared to HRR, MCR slope provides significant prognostic information in HF patients. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
AIM—To reassess QT interval rate correction. BACKGROUND—The QT interval is strongly and inversely related to heart rate. To compare QT intervals between different subjects with different heart rates requires the application of a QT interval rate correction formula. To date these formulae have inappropriately assumed a fixed relation between QT interval and heart rate. An alternative method of QT interval rate correction that makes no assumptions about the QT interval-heart rate relation is ne...
Bruno Ramos Nascimento
Full Text Available Background: Heart rate variability (HRV is a marker of autonomic dysfunction severity. The effects of physical training on HRV indexes in Chagas heart disease (CHD are not well established. Objective: To evaluate the changes in HRV indexes in response to physical training in CHD. Methods: Patients with CHD and left ventricular (LV dysfunction, physically inactive, were randomized either to the intervention (IG, N = 18 or control group (CG, N = 19. The IG participated in a 12-week exercise program consisting of 3 sessions/week. Results: Mean age was 49.5 ± 8 years, 59% males, mean LVEF was 36.3 ± 7.8%. Baseline HRV indexes were similar between groups. From baseline to follow-up, total power (TP: 1653 (IQ 625 - 3418 to 2794 (1617 - 4452 ms, p = 0.02 and very low frequency power: 586 (290 - 1565 to 815 (610 - 1425 ms, p = 0.047 increased in the IG, but not in the CG. The delta (post - pre HRV indexes were similar: SDNN 11.5 ± 30.0 vs. 3.7 ± 25.1 ms. p = 0.10; rMSSD 2 (6 - 17 vs. 1 (21 - 9 ms. p = 0.43; TP 943 (731 - 3130 vs. 1780 (921 - 2743 Hz. p = 0.46; low frequency power (LFP 1.0 (150 - 197 vs. 60 (111 - 146 Hz. p = 0.85; except for high frequency power, which tended to increase in the IG: 42 (133 - 92 vs. 79 (61 - 328 Hz. p = 0.08. Conclusion: In the studied population, the variation of HRV indexes was similar between the active and inactive groups. Clinical improvement with physical activity seems to be independent from autonomic dysfunction markers in CHD.
Matchett, Gerald; Wood, Philip
The human heart normally exhibits robust beat-to-beat heart rate variability (HRV). The loss of this variability is associated with pathology, including disease states such as congestive heart failure (CHF). The effect of general anesthesia on intrinsic HRV is unknown. In this prospective, observational study we enrolled 100 human subjects having elective major surgical procedures under general anesthesia. We recorded continuous heart rate data via continuous electrocardiogram before, during, and after anesthesia, and we assessed HRV of the R-R intervals. We assessed HRV using several common metrics including Detrended Fluctuation Analysis (DFA), Multifractal Analysis, and Multiscale Entropy Analysis. Each of these analyses was done in each of the four clinical phases for each study subject over the course of 24 h: Before anesthesia, during anesthesia, early recovery, and late recovery. On average, we observed a loss of variability on the aforementioned metrics that appeared to correspond to the state of general anesthesia. Following the conclusion of anesthesia, most study subjects appeared to regain their normal HRV, although this did not occur immediately. The resumption of normal HRV was especially delayed on DFA. Qualitatively, the reduction in HRV under anesthesia appears similar to the reduction in HRV observed in CHF. These observations will need to be validated in future studies, and the broader clinical implications of these observations, if any, are unknown.
Hansen, Dominique; Wens, Inez; Dendale, Paul; Op' t Eijnde, Bert
OBJECTIVE:To explore the etiology of exercise intolerance in patients with MS, it is analyzed whether a disturbed cardiac autonomic control could be observed during exercise testing in patients with MS, and is related to exercise tolerance. PATIENTS AND METHOD:From 26 MS patients and 15 healthy subjects, exercise-onset (first 20 and 60 seconds) and –offset (1-minute recovery) HR change was determined during a 6-minute constant-load exercise bout on bike. Blood lactate, HR, oxygen uptake, e...
Edelhäuser, Friedrich; Minnerop, Antje; Trapp, Barbara; Büssing, Arndt; Cysarz, Dirk
Mind-body therapies are beneficial for several diseases (e.g. chronic pain, arterial hypertension, mood disorders). Eurythmy therapy (EYT) is a mind-body therapy from Anthroposophic Medicine. In each EYT exercise a short sequence of body movements and simultaneous guided imagery is repeated several times. In this study, the simultaneous effects of two different EYT exercises on cardiac autonomic regulation as assessed by spectral analysis of heart rate variability (HRV) were investigated. Twenty healthy subjects (age: 29.1 ± 9.3 years, 13 female) performed two different EYT exercises (EYT-A and EYT-B) for 8 min. Each EYT exercise was compared against two matched control exercises: control exercise 1 (CE1-A and CE1-B) consisted of a repetition of the body movements of the EYT exercise but without guided imagery, control exercise 2 consisted of walking on the spot (CE2-A and CE2-B). Spectral power of HRV during each exercise was quantified on the basis of Holter ECG recordings. During EYT-A the frequency of the peak oscillation in the very low frequency (VLF) band matched the repetition rate of the sequence of body movements (0.02 Hz). Low frequency (LF) oscillations were augmented when compared to the control exercises (EYT-A: 7.31 ± 0.84, CE1-A: 6.98 ± 0.90, CE2-A: 6.52 ± 0.87 ln ms(2), p exercises (EYT-B: 9.32 ± 0.82, CE1-B: 6.31 ± 0.75, CE2-B: 6.04 ± 0.80 ln ms(2), p exercises clearly affected cardiac autonomic regulation in a rhythmic manner according to the stimulus of the specific body movements of each EYT exercise. These results offer a physiological basis to develop a rationale for specific clinical indications of these EYT exercises such as stress reduction or prevention of hypertension. DRKS00006760 (registered on 10/10/2014, i.e. retrospective registration); view details at http://www.drks.de/DRKS00006760.
Bouquier, L; Amand, M; Van Eecke, D
To study heart rate variability during sleep in children with multiple disabilities in order to observe the behavior of the autonomic nervous system. The R-R interval variability of 4 to 12 years old children was recorded with a heart rate monitor during one night. Children with multiple disabilities (G1) and healthy children (G2) were compared in time, frequency, and non-linear domains. Temporal (P0.05). The diseases encountered are probably the reason for these findings, but the variety of disorders and medications of the children with multiple disabilities needs to be studied with a larger and more varied sample. Sympathetic predominance during sleep in children with multiple disabilities is associated with a decrease in adaptive abilities of these children's autonomic nervous system. Copyright © 2013 Elsevier Masson SAS. All rights reserved.
Park, Andres E; Huynh, Pauline; Schell, Anne M; Baker, Laura A
Reduced cardiovascular responses to psychological stressors have been found to be associated with both obesity and negative affect in adults, but have been less well studied in children and adolescent populations. These findings have most often been interpreted as reflecting reduced sympathetic nervous system response, perhaps associated with heightened baseline sympathetic activation among the obese and those manifesting negative affect. However, obesity and negative affect may themselves be correlated, raising the question of whether they both independently affect cardiovascular reactivity. The present study thus examined the separate effects of obesity and negative affect on both cardiovascular and skin conductance responses to stress (e.g., during a serial subtraction math task) in adolescents, while controlling for baseline levels of autonomic activity during rest. Both obesity and negative affect had independent and negative associations with cardiovascular reactivity, such that reduced stress responses were apparent for obese adolescents and those with high levels of negative affect. In contrast, neither obesity nor negative affect was related to skin conductance responses to stress, implicating specifically noradrenergic mechanisms rather than sympathetic mechanisms generally as being deficient. Moreover, baseline heart rate was unrelated to obesity in this sample, which suggests that heightened baseline of sympathetic activity is not necessary for the reduced cardiovascular reactivity to stress. Copyright © 2015 Elsevier B.V. All rights reserved.
Toshio Matsuoka; Harumi Kawase; Ichie Matsumoto; Yoshihiro Kato; Kazuo Oguri; Siqin Bai; Na Du
The aim of the present study was to examine the effects of endurance training on heart rate (HR) recovery after exercise and cardiac autonomic nervous system (ANS) modulation in female marathon runners by comparing with untrained controls. Six female marathon runners (M group) aged 32-40 years and eight age-matched untrained females (C group) performed a maximum-effort treadmill running exercise. Maximal oxygen uptake (VO2max) was measured during the exercise with a gas analyzer connected to ...
Full Text Available The present study aimed to assess changes in resting and maximum heart rates as primary indicators of cardiac autonomic function in metabolic syndrome (MetS patients and to determine their value for discriminating MetS from non-MetS. 468 participants were enrolled in this cross-sectional study and assessed according to the updated adult treatment panel III (ATP-III definition of MetS. Resting and maximum heart rates were recorded following the Bruce protocol during an exercise. A receiver operating characteristic (ROC curve was used to identify the best cutoff point for discriminating MetS from the non-MetS state. 194 participants (41.5% were diagnosed as MetS. The mean resting heart rate (RHR was not statistically different between the two groups (P=0.078. However, the mean maximum heart (MHR rate was considerably higher in participants with MetS (142.37±14.84 beats per min compared to the non-MetS group (134.62±21.63 beats per min (P<0.001. In the MetS group, the MHR was positively correlated with the serum triglyceride level (β=0.185, P=0.033 and was inversely associated with age (β=-0.469, P<0.001. The MHR had a moderate value for discriminating MetS from the non-MetS state (c=0.580, P=0.004 with the optimal cutoff point of 140 beats per min. In MetS patients, the MHR was significantly greater compared to non-MetS subjects and was directly correlated with serum triglyceride levels and inversely with advanced age. Moreover, MHR can be used as a suspicious indicator for identifying MetS.
Walker, G. H., Baber , C., & Jenkins, D. P. (2005). Human Factors Methods: A Practical Guide for Engineering and Design. Burlington, VT: Ashgate...the training, subjects were asked if they were ready to begin the experiment or if they wanted any extra time to practice . Test Sessions and Testing...intrusive and not practical for day-to-day operations. Several imaging techniques have been developed to remotely measure heart rate; however, each
Sorensen, Gertrud Laura; Kempfner, Jacob; Zoetmulder, Marielle
The objective of this study was to determine whether patients with Parkinson's disease with and without rapid‐eye‐movement sleep behavior disorder and patients with idiopathic rapid‐eye‐movement sleep behavior disorder have an attenuated heart rate response to arousals or to leg movements during...... associated with arousal or leg movement from all sleep stages was analyzed from 10 heartbeats before the onset of the sleep event to 15 heartbeats following onset of the sleep event. The heart rate reponse to arousals was significantly lower in both parkinsonian groups compared with the control group...
Frequency domain representation of a short-term heart-rate time series (HRTS) signal is a popular method for evaluating the cardiovascular control system. The spectral parameters, viz. percentage power in low frequency band (%PLF), percentage power in high frequency band (%PHF), power ratio of low frequency to high ...
Amelsvoort, van L.G.P.M.; Schouten, E.G.; Maan, A.C.; Swenne, C.A.; Kok, F.J.
OBJECTIVES To investigate whether an increased risk of cardiovascular disease might be caused by increased arrhythmogeneity and by unfavourable changes in autonomic cardiac control the changes in the occurrence of premature complexes (PVCs) and in heart rate variability (HRV) were studied in
Niemeijer, Nicolasine D; Corssmit, Eleonora P M; Reijntjes, Robert H A M; Lammers, Gert Jan; van Dijk, J Gert; Thijs, Roland D
The carotid bodies are thought to play an important role in sleep-dependent autonomic changes. Patients who underwent resection of bilateral carotid body tumors have chronically attenuated baroreflex sensitivity. These subjects provide a unique opportunity to investigate the role of the baroreflex during sleep. One-night ambulatory polysomnography (PSG) recording. Participants' homes. Nine patients with bilateral carotid body tumor resection (bCBR) (four women, mean age 50.4 ± 7.2 years) and nine controls matched for age, gender, and body mass index. N/A. Sleep parameters were obtained from PSG. Heart rate (HR) and its variability were calculated using 30-s epochs. In bCBR patients, HR was slightly but not significantly increased during wake and all sleep stages. The effect of sleep on HR was similar for patients and controls. Low frequency (LF) power of the heart rate variability spectrum was significantly lower in bCBR patients in active wakefulness, sleep stage 1 and REM sleep. No differences were found between patients and controls for high frequency (HF) power and the LF/HF ratio. Bilateral carotid body tumor resection (bCBR) is associated with decreased low frequency power during sleep, suggesting impaired baroreflex function. Despite this, sleep-related heart rate changes were similar between bCBR patients and controls. These findings suggest that the effects of sleep on heart rate are predominantly generated through central, non-baroreflex mediated pathways. © 2015 Associated Professional Sleep Societies, LLC.
Snieder, H.; van Doornen, L.J.P.; Boomsma, D.I.; Thayer, J.F.
We investigated whether women show larger heart rate variability (HRV) than men after controlling for a large number of health-related covariates, using two indices of HRV, namely respiratory sinus arrhythmia (RSA) and approximate entropy (ApEn). In a twin design, the heritability of both indices
I.M. Nolte (Ilja); Munoz, M.L. (M. Loretto); V. Tragante (Vinicius); A.T. Amare (Azmeraw T); R. Jansen; A. Vaez (Ahmad); Von Der Heyde, B. (Benedikt); C.L. Avery; J.C. Bis (Joshua); B. Dierckx (Bram); J. van Dongen (Jenny); S.M. Gogarten; P. Goyette (Philippe); Hernesniemi, J. (Jussi); V. Huikari (Ville); S.-J. Hwang (Shih-Jen); Jaju, D. (Deepali); K.F. Kerr (Kathleen); A. Kluttig (Alexander); Krijthe, B.P. (Bouwe P.); Kumar, J. (Jitender); S.W. Van Der Laan (Sander W.); L.-P. Lyytikäinen (Leo-Pekka); Maihofer, A.X. (Adam X.); Minassian, A. (Arpi); P.J. van der Most (Peter); M. Müller-Nurasyid (Martina); M. Nivard (Michel); Salvi, E. (Erika); Stewart, J.D. (James D.); J.F. Thayer (Julian); Verweij, N. (Niek); Wong, A. (Andrew); D. Zabaneh (Delilah); M.H. Zafarmand (Mohammad Hadi); A. Abdellaoui (Abdel); Albarwani, S. (Sulayma); C.M. Albert (Christine); A. Alonso (Alvaro); Ashar, F. (Foram); Auvinen, J. (Juha); T. Axelsson (Tomas); Baker, D.G. (Dewleen G.); P.I.W. de Bakker (Paul); Barcella, M. (Matteo); Bayoumi, R. (Riad); Bieringa, R.J. (Rob J.); D.I. Boomsma (Dorret); G. Boucher (Gabrielle); A.R. Britton; Christophersen, I.E. (Ingrid E.); Dietrich, A. (Andrea); G.B. Ehret (Georg); P.T. Ellinor (Patrick); Eskola, M. (Markku); J.F. Felix (Janine); Floras, J.S. (John S.); O.H. Franco (Oscar); Friberg, P. (Peter); Gademan, M.G.J. (Maaike G. J.); Geyer, M.A. (Mark A.); V. Giedraitis (Vilmantas); C.A. Hartman (Catharina A.); Hemerich, D. (Daiane); A. Hofman (Albert); J.J. Hottenga (Jouke Jan); H.V. Huikuri (Heikki); Hutri-Kähönen, N. (Nina); X. Jouven (Xavier); M.J. Junttila (Juhani); Juonala, M. (Markus); A. Kiviniemi (Antti); J.A. Kors (Jan); M. Kumari (Meena); Kuznetsova, T. (Tatiana); C.C. Laurie (Cathy); J.D. Lefrandt; Y. Li (Yong); Y. Li (Yun); Liao, D. (Duanping); Limacher, M.C. (Marian C.); Lin, H.J. (Henry J.); C.M. Lindgren (Cecilia M.); S.A. Lubitz (Steven); A. Mahajan (Anubha); B. McKnight (Barbara); Meyer Zu Schwabedissen, H. (Henriette); Milaneschi, Y. (Yuri); Mononen, N. (Nina); A.P. Morris (Andrew); M.A. Nalls (Michael); G. Navis (Gerjan); Neijts, M. (Melanie); K. Nikus (Kjell); K.E. North (Kari); O'Connor, D.T. (Daniel T.); Ormel, J. (Johan); S. Perz (Siegfried); A. Peters (Annette); Psaty, B.M. (Bruce M.); Raitakari, O.T. (Olli T.); Risbrough, V.B. (Victoria B.); M.F. Sinner (Moritz); D.S. Siscovick (David); G.D. Smith; N.L. Smith (Nicholas); E.Z. Soliman (Elsayed); N. Sotoodehnia (Nona); Staessen, J.A. (Jan A.); Stein, P.K. (Phyllis K.); Stilp, A.M. (Adrienne M.); Stolarz-Skrzypek, K. (Katarzyna); K. Strauch (Konstantin); J. Sundstrom (Johan); C.A. Swenne (Cees); A.C. Syvänen; J.-C. Tardif (Jean-Claude); K.D. Taylor (Kent); A. Teumer (Alexander); Thornton, T.A. (Timothy A.); Tinker, L.E. (Lesley E.); A.G. Uitterlinden (André); J. van Setten (Jessica); Voss, A. (Andreas); M. Waldenberger (Melanie); Wilhelmsen, K.C. (Kirk C.); G.A.H.M. Willemsen (Gonneke); Q. Wong (Quenna); Z. Zhang (Z.); A.B. Zonderman; D. Cusi (Daniele); M. Evans (Michele); Greiser, H.K. (Halina K.); Van Der Harst, P. (Pim); Hassan, M. (Mohammad); E. Ingelsson (Erik); M.-R. Jarvelin (Marjo-Riitta); S. Kääb (Stefan); M. Kähönen (Mika); M. Kivimaki (Mika); C. Kooperberg (Charles); D. Kuh (Diana); T. Lehtimäki (Terho); W.H.L. Kao (Wen); C.M. Nievergelt (Caroline M); O'Donnell, C.J. (Chris J.); A.J. Oldehinkel (Albertine); B.W.J.H. Penninx (Brenda); A. Reiner (Alexander); H. Riese (Harriëtte); A.M.M. van Roon (Arie); Rioux, J.D. (John D.); J.I. Rotter (Jerome I.); Sofer, T. (Tamar); B.H.Ch. Stricker (Bruno); H.W. Tiemeier (Henning); T.G.M. Vrijkotte (Tanja); F.W. Asselbergs (Folkert); B.J.J.M. Brundel (Bianca); S.R. Heckbert (Susan); E.A. Whitsel; M. den Hoed (Marcel); H. Snieder (Harold); E.J.C. de Geus (Eco)
textabstractReduced 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
Kolus, Ahmet; Imbeau, Daniel; Dubé, Philippe-Antoine; Dubeau, Denise
In a new approach based on adaptive neuro-fuzzy inference systems (ANFIS), field heart rate (HR) measurements were used to classify work rate into four categories: very light, light, moderate, and heavy. Inter-participant variability (physiological and physical differences) was considered. Twenty-eight participants performed Meyer and Flenghi's step-test and a maximal treadmill test, during which heart rate and oxygen consumption (VO2) were measured. Results indicated that heart rate monitoring (HR, HRmax, and HRrest) and body weight are significant variables for classifying work rate. The ANFIS classifier showed superior sensitivity, specificity, and accuracy compared to current practice using established work rate categories based on percent heart rate reserve (%HRR). The ANFIS classifier showed an overall 29.6% difference in classification accuracy and a good balance between sensitivity (90.7%) and specificity (95.2%) on average. With its ease of implementation and variable measurement, the ANFIS classifier shows potential for widespread use by practitioners for work rate assessment. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.
Mar 16, 1988 ... have investigated aspects of thermoregulation, but the results obtained are contradictory, and no heart rate measurements were done. The purpose of this study was to investigate the heating and cooling rates of the angulate tortoise, Chersina angulata, in the eastern Cape Province,. South Africa.
... rates increase with increasing body temperature, and for all body temperatures heart rates were greater during heating than during cooling. This suggests that the cardiovascular system plays a role in the heat exchange of the tortoises, but further study is required to completely understand the thermoregulatory process.
Robazza, C; Bortoli, L; Nougier, V
A case study of an elite female archer was conducted to gain insight into individual psychophysical reactions accompanying an athletic event, and to test predictions of pre-performance emotions effects upon performance. Good performance was expected when the actual pre-performance emotions resembled the recalled optimal emotion pattern. Conversely, poor performance was expected when the actual pre-performance emotions paralleled the recalled ineffective emotion pattern. the investigation comprised individual emotion profiling, emotions and heart rate monitoring, final interview and performance evaluation. The research was accomplished during the 1996 European Archery Championships, one of the most important international archery competitions. An 18-year-old female athlete of the Italian archery national team. Because of the exploratory nature of the study, no intervention was implemented. Emotion profiling was carried out using an idiographic approach based on recalled optimal and poor performances, according to the Individual Zones of Optimal Functioning (IZOF) model. Emotions, heart rate, and performance were monitored across the five days of practice and competition. Individual pre-performance optimal emotion pattern, heart rate deceleration during shooting, consistent shooting scores were revealed throughout practice and competition. The good performance predicted on the basis of pre-performance emotion assessments was met and was confirmed by the archer's interpretation.
Wachowiak, Mark P; Hay, Dean C; Johnson, Michel J
Because of its utility in the investigation and diagnosis of clinical abnormalities, heart rate variability (HRV) has been quantified with both time and frequency analysis tools. Recently, time-frequency methods, especially wavelet transforms, have been applied to HRV. In the current study, a complementary computational approach is proposed wherein continuous wavelet transforms are applied directly to ECG signals to quantify time-varying frequency changes in the lower bands. Such variations are compared for resting and lower body negative pressure (LBNP) conditions using statistical and information-theoretic measures, and compared with standard HRV metrics. The latter confirm the expected lower variability in the LBNP condition due to sympathetic nerve activity (e.g. RMSSD: p=0.023; SDSD: p=0.023; LF/HF: p=0.018). Conversely, using the standard Morlet wavelet and a new transform based on windowed complex sinusoids, wavelet analysis of the ECG within the observed range of heart rate (0.5-1.25Hz) exhibits significantly higher variability, as measured by frequency band roughness (Morlet CWT: p=0.041), entropy (Morlet CWT: p=0.001), and approximate entropy (Morlet CWT: p=0.004). Consequently, this paper proposes that, when used with well-established HRV approaches, time-frequency analysis of ECG can provide additional insights into the complex phenomenon of heart rate variability. Copyright © 2016. Published by Elsevier Ltd.
Full Text Available The automated detection of stress is a central problem for ambient assisted living solutions. The paper presents the concepts and results of two studies targeted at stress detection with a low cost heart rate sensor, a chest belt. In the device validation study (n=5, we compared heart rate data and other features from the belt to those measured by a gold standard device to assess the reliability of the sensor. With simple synchronization and data cleaning algorithm, we were able to select highly (>97% correlated, low average error (2.2% data segments of considerable length from the chest data for further processing. The protocol for the clinical study (n=46 included a relax phase followed by a phase with provoked mental stress, 10 minutes each. We developed a simple method for the detection of the stress using only three time-domain features of the heart rate signal. The method produced accuracy of 74.6%, sensitivity of 75.0%, and specificity of 74.2%, which is impressive compared to the performance of two state-of-the-art methods run on the same data. Since the proposed method uses only time-domain features, it can be efficiently implemented on mobile devices.
Kowal, M.; Kubal, S.; Piotrowski, P.; Staniec, K.
A surface reflection-based method for measuring heart rate and saturation has been introduced as one having a significant advantage over legacy methods in that it lends itself for use in special applications such as those where a person’s mobility is of prime importance (e.g. during a miner’s work) and excluding the use of traditional clips. Then, a complete ATmega1281-based microcontroller platform has been described for performing computational tasks of signal processing and wireless transmission. In the next section remarks have been provided regarding the basic signal processing rules beginning with raw voltage samples of converted optical signals, their acquisition, storage and smoothing. This chapter ends with practical remarks demonstrating an exponential dependence between the minimum measurable heart rate and the readout resolution at different sampling frequencies for different cases of averaging depth (in bits). The following section is devoted strictly to the heart rate and hemoglobin oxygenation (saturation) measurement with the use of the presented platform, referenced to measurements obtained with a stationary certified pulsoxymeter.
Burns, Katrina N; Sun, Kan; Fobil, Julius N; Neitzel, Richard L
Electronic waste (e-waste) is a growing occupational and environmental health issue around the globe. E-waste recycling is a green industry of emerging importance, especially in low-and middle-income countries where much of this recycling work is performed, and where many people's livelihoods depend on this work. The occupational health hazards of e-waste recycling have not been adequately explored. We performed a cross-sectional study of noise exposures, heart rate, and perceived stress among e-waste recycling workers at a large e-waste site in Accra, Ghana. We interviewed 57 workers and continuously monitored their individual noise exposures and heart rates for up to 24 h. More than 40% of workers had noise exposures that exceeded recommended occupational (85 dBA) and community (70 dBA) noise exposure limits, and self-reported hearing difficulties were common. Workers also had moderate to high levels of perceived stress as measured via Cohen's Perceived Stress Scale, and reported a variety of symptoms that could indicate cardiovascular disease. Noise exposures were moderately and significantly correlated with heart rate (Spearman's ρ 0.46, p noise exposure was associated with a 0.17 increase in heart rate (p-value = 0.01) even after controlling for work activities, age, smoking, perceived stress, and unfavorable physical working conditions. These findings suggest that occupational and non-occupational noise exposure is associated with elevations in average heart rate, which may in turn predict potential cardiovascular damage.
Galli, Alessio; Lombardi, Federico
The exact mechanisms of sudden unexpected death in epilepsy remain elusive, despite there is consensus that SUDEP is associated with severe derangements in the autonomic control to vital functions as breathing and heart rate regulation. Heart rate variability (HRV) has been advocated as biomarker of autonomic control to the heart. Cardiac dysautonomia has been found in diseases where other branches of the autonomous nervous system are damaged, as Parkinson disease and multiple system atrophy. In this perspective, an impaired HRV not only is a risk factor for sudden cardiac death mediated by arrhythmias, but also a potential biomarker for monitoring a progressive decline of the autonomous nervous system. This slope may lead to an acute imbalance of the regulatory pathways of vital functions after seizure and then to SUDEP. Copyright © 2016 Elsevier Ltd. All rights reserved.
Full Text Available Frequent ventricular extrasystoles (VE can affect haemodynamic indexes and lead to negative consequences for the health of not only an expectant mother, but also a fetus. The analysis of heart rate variability (HRV is recognized as an informative method for noninvasive assessment of the impact of the autonomic nervous system on the cardiovascular system. HRV in pregnant women has been understudied. Therefore, the goal of the present research is to investigate HRV indexes in pregnant women with frequent VE in the 3-rd trimester of pregnancy and early postnatal period. Materials and Methods HRV was estimated in 40 pregnant women with frequent VE, who were divided into 2 groups: group 1– in the 3-rd trimester of pregnancy, and group 2 – in the early postnatal period. A control group included 20 normal pregnant women without any arrhythmias. In addition, HRV indexes in these groups were compared to the indexes in the group of healthy non-pregnant women at the age of 18 to 30. The investigation of HRV was conducted by using the 24-hour HM-ECG with “Valenta” cardioregistrator (Russia. SDNN, SDAN, HRVi, HF, LF, VLF and LF/HF indexes of HRV were under the study. Results The analysis of time indexes revealed the decreased of HRV during pregnancy: in the 3-rd trimester SDNN decreased. In the postnatal period SDNN increased. It was found that rMSSD decresed in pregnant women and increased in the postnatal period that is indicative of enhanced parasympathetic effects. Similar dynamics was noted in analyzing the HF index associated with vagal activity. Vagal activity tended to decrease in pregnancy as compared to its normal values and increased significantly in the early postnatal period. We sould note that the LF waves activity reflecting the sympathetic effects on the heart increased gradually in pregnant women and decreased in the postnatal period. Discussion and Conclusions The investigation of HRV allows to estimate an extent of the autonomic
Full Text Available The aim of the present study was to examine the effects of endurance training on heart rate (HR recovery after exercise and cardiac autonomic nervous system (ANS modulation in female marathon runners by comparing with untrained controls. Six female marathon runners (M group aged 32-40 years and eight age-matched untrained females (C group performed a maximum-effort treadmill running exercise. Maximal oxygen uptake (VO2max was measured during the exercise with a gas analyzer connected to subjects through a face mask. Heart rate, blood pressure and blood lactate were measured before and after the exercise. Rating of perceived exertion (RPE to the exercise was obtained immediately after the exercise. Holter ECG was recorded and analyzed with power spectral analysis of heart rate variability (HRV to investigate the cardiac ANS modulation. The M group had significantly higher VO2max, faster HR recovery after exercise, higher Mean RR, SDRR, HF power and lower LF/HF ratio at rest compared with the C group. The M group also presented greater percent decrease of blood pressure after exercise, although their blood pressure after exercise was higher than the C group. It is suggested that endurance training induced significant alterations in cardiac ANS modulation at rest and significant acceleration of HR recovery after exercise in female marathon runners. Faster HR recovery after exercise in the female marathon runners should result from their higher levels of HRV, higher aerobic capacity and exaggerated blood pressure response to exercise compared with untrained controls.
Taçoy, Gülten; Açikgöz, Kadri; Kocaman, Sinan Altan; Ozdemir, Murat; Cengel, Atiye
To investigate the effect of body mass index (BMI) on heart rate variability (HRV) and inflammatory parameters in patients with heart failure. We analyzed 55 consecutive patients (mean age, 63.5 +/- 12.8 years; male/female, 39/16) with symptomatic left ventricular systolic (ejection fraction or= 30 kg/m2). The cause of heart failure was mainly ischemic heart disease (75%) with mean ejection fraction 30 +/- 7%. Plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) and C-reactive protein levels were measured, and time-domain HRV indices were determined on Holter electrocardiogram. The relationship between HRV indices and laboratory, inflammatory and echocardiographic parameters was investigated with correlation analysis. Age, sex, clinical characteristics (hypertension, diabetes mellitus, dyslipidemia, family history, smoking) were similar between groups. BMI was inversely correlated with NT-pro BNP levels (P = 0.001). HRV indices did not differ between groups. Correlation analysis demonstrated the relationship between HRV indices and fasting blood glucose (SDNN, SDANN, SDNNI, root mean square successive differences, VTI), C-reactive protein (SDANN, SDNNI, VTI), pulmonary artery pressure (SDNN, SDANN, VTI) levels. In systolic heart failure patients a higher BMI is associated with decreased NT-proBNP levels. Although HRV indices were not different between groups, inflammatory parameters, fasting blood glucose and pulmonary artery pressure were correlated with them.
Verspyck, E; Sentilhes, L
To determine labour management procedures associated with an increased risk of fetal heart rate anomalies and to assess the effectiveness of various intrauterine resuscitation techniques for fetal distress. The literature search was carried out systematically on Medline and Cochrane database between 1980 and June 2007 was performed. Early amniotomy and/or active management of labour reduce the duration of the first stage of labour without affecting the rate of caesarean section (level of evidence 1). Early amniotomy increases the frequency of severe variable fetal heart rate decelerations (level of evidence 1). High doses of oxytocin and decrease in the oxytocin-dosing interval for augmentation of labour both induce uterine hyperstimulation (level of evidence 1). Increased uterine activity is associated with a higher incidence of fetal heart rate abnormalities and neonatal acidosis (level of evidence 3). Fetal heart rate decelerations in supine position may disappear in the lateral position (level of evidence 3). In prophylactic maternal oxygenation administration abnormal cord blood pH values (less than 7.2) are more frequent in the oxygenation group than in the control group (level of evidence 2) and its efficacy in fetal distress is not evaluated until now. Amnioinfusion in the presence of thick meconium staining does not reduce the risk of perinatal death or meconium aspiration syndrome (level of evidence 1). Transcervical saline amnioinfusion might relieve variable decelerations during labour (level of evidence 3). Prophylactic amnioinfusion for intrapartum oligohydramnios reduces fetal heart rate abnormalities and overall rates of caesarean deliveries (level of evidence 2). Acute tocolysis may be helpful in cases of intrapartum fetal distress related to uterine hyperactivity (level of evidence 2). Early amniotomy and high doses of oxytocin may both increase the risk of fetal heart rate anomalies, but are both useful for avoiding prolonged labour. More
Speed control variable rate irrigation (VRI) is used to address within field variability by controlling a moving sprinkler’s travel speed to vary the application depth. Changes in speed are commonly practiced over areas that slope, pond or where soil texture is predominantly different. Dynamic presc...
Karageorghis, CI; Jones, L; Low, DC
The present study examined the predicted positive and linear relationship (Iwanaga, 1995a,1995b) between exercise heart rate and music tempo preference. Initially, 128 undergraduates (M 3 age = 20.0 years, SD = 0.9 years) were surveyed to establish their three favorite music artists of all time. A separate experimental group of 29 undergraduates (M age = 20.3 years, SD = 1.2 years) selected the music of a single artist from a choice of the three highest-rated artists from the earlier survey. ...
Buxton, Roxanne E.; West, Michael R.; Kalogera, Kent L.; Hanson, Andrea M.
Heart rate monitoring is required during exercise for crewmembers aboard the International Space Station (ISS) and will be for future exploration missions. The cardiovascular system must be sufficiently stressed throughout a mission to maintain the ability to perform nominal and contingency/emergency tasks. High quality heart rate data is required to accurately determine the intensity of exercise performed by the crewmembers and show maintenance of VO2max. The quality of the data collected on ISS is subject to multiple limitations and is insufficient to meet current requirements. PURPOSE: To evaluate the performance of commercially available Bluetooth® heart rate monitors (BT_HRM) and their ability to provide high quality heart rate data to monitor crew health on board ISS and during future exploration missions. METHODS: Nineteen subjects completed 30 data collection sessions of various intensities on the treadmill and/or cycle. Subjects wore several BT_HRM technologies for each testing session. One electrode-based chest strap (CS) was worn, while one or more optical sensors (OS) was worn. Subjects were instrumented with a 12-lead ECG to compare the heart rate data from the Bluetooth sensors. Each BT_RHM data set was time matched to the ECG data and a +/-5bpm threshold was applied to the difference between the two data sets. Percent error was calculated based on the number of data points outside the threshold and the total number of data points. REULTS: The electrode-based chest straps performed better than the optical sensors. The best performing CS was CS1 (1.6%error), followed by CS4 (3.3%error), CS3 (6.4%error), and CS2 (9.2%error). The OS resulted in 10.4% error for OS1 and 14.9% error for OS2. CONCLUSIONS: The highest quality data came from CS1, unfortunately it has been discontinued by the manufacturer. The optical sensors have not been ruled out for use, but more investigation is needed to determine how to get the best quality data. CS2 will be used in an
Lee, Kyunghee; Park, Jeongeon; Choi, Jeongim; Park, Chang Gi
Reduced heart rate variability significantly increases cardiovascular mortality. Metabolic syndrome increases the cardiac autonomic dysfunction. Recently, increasing cardiovascular mortality has been reported in patients with schizophrenia. This study was done to compare heart rate variability between adults with and without schizophrenia and to compare the relationship of heart rate variability to metabolic syndrome in hospitalized patients with schizophrenia. This was a descriptive and correlational study in which 719 adults without schizophrenia and 308 adults with schizophrenia took part between May and June 2008. We measured the following: five-minute heart rate variability; high-frequency, low-frequency, the ratio of low-frequency to high-frequency, and the Standard Deviation of all the normal RR intervals. Data was also collected on metabolic syndrome, abdominal obesity, triglycerides, HDL cholesterol, blood pressure and fasting glucose. The Standard Deviation of all the normal RR intervals values of heart rate variability indices were 1.53±0.18. The low-frequency and high-frequency values of heart rate variability indices were significantly higher in hospitalized patients with schizophrenia (3.89±1.36; 3.80±1.20) than those in the healthy participants (2.20±0.46; 2.10±0.46). There were no significant differences between the schizophrenic patients with and without metabolic syndrome. The results of this study indicate that schizophrenia patients have significantly lower cardiac autonomic control, but they have significantly higher low-frequency and high-frequency values than those of healthy adults. Use of antipsychotic drug may affect the autonomic nervous system in schizophrenic patients. Metabolic syndrome was not associated with cardiac autonomic control in schizophrenia patients.
Dogdu, Orhan; Yarlioglues, Mikail; Kaya, Mehmet Gungor; Ardic, Idris; Oguzhan, Nilufer; Akpek, Mahmut; Sahin, Omer; Akyol, Lutfi; Kelesoglu, Saban; Koc, Fatih; Ozdogru, Ibrahim; Oguzhan, Abdurrahman
Systemic lupus erythematosus (SLE) is an autoimmune disorder resulting in multisystemic inflammatory damage. It is reported that cardiovascular diseases (CVD) are responsible for 20%-30% of deaths in patients with SLE. Heart rate recovery after exercise is a function of vagal reactivation, and its impairment is an independent prognostic indicator for cardiovascular and all-cause mortality. The aim of our study was to evaluate the heart rate recovery index in patients with SLE. The study population included 48 patients with SLE (35 women, mean age 46.3 ± 12.8 yrs, mean disease duration 6.0 ± 2.3 yrs) and 44 healthy controls (30 women, mean age 45.7 ± 12.9 yrs). Basal electrocardiography, echocardiography, and treadmill exercise testing were performed on all patients and controls. The heart rate recovery index was defined as the reduction in the heart rate from the rate at peak exercise to the rate at the first minute (HRR(1)), second minute (HRR(2)), third minute (HRR(3)), and fifth minute (HRR(5)) after stopping exercise stress testing. There were significant differences in HRR(1) and HRR(2) indices between patients with SLE and the control group (24.1 ± 6.5 vs 33.3 ± 9.3; p < 0.001, and 44.6 ± 13.3 vs 53.7 ± 9.9; p < 0.001, respectively). Similarly, HRR(3) and HRR(5) indices of the recovery period were lower in patients with SLE, compared with indices in the control group (57.6 ± 13.0 vs 64.9 ± 11.7; p = 0.006, and 67.2 ± 12.3 vs 75.0 ± 15.4; p = 0.009, respectively). Effort capacity was markedly lower (9.0 ± 1.9 vs 11.1 ± 2.3 metabolic equivalents; p = 0.001, respectively) among the patients with SLE. The heart rate recovery index is deteriorated in patients with SLE. When the prognostic significance of the heart rate recovery index is considered, these results may contribute to explain the increased occurrence of cardiac death. It points to the importance of the heart rate recovery index in the identification of high-risk patients.
Landreani, Federica; Caiani, Enrico Gianluca
Micro-electro-mechanical systems technology, now embedded into smartphones, potentially allows measuring heart mechanical activity by positioning the phone on the body and acquiring vibrational signals, without the need for additional peripherals or interfaces. However, lack of standardization in experimental protocol, processing methodology and validation procedures, together with the wide range of available smartphones on the market, impact on the comparability of results and their general validity. The aim of this review is to provide information on the state-of-the art of research in this field, with current limitations and potentials, thus potentially serving as a basis for the creation of a standard based on current experiences. Areas covered: The review focused on studies relevant to the extraction of the heart rate using accelerometric technology, searching for relevant literature (papers or conference proceedings) both in Pubmed and IEEE eXplore engines. Expert commentary: From the results of this review, the smartphone can be considered a powerful device able to accurately measure the resting heart rate, thanks to embedded accelerometer technology. However, lack of a shared standard in the acquisition protocol and analysis procedure, thus affecting user-collected data reliability, could limit clinical acceptability and prevent recommending this approach as a self-tracking tool in patients.
Doran, Charlotte R; Estévez-Lao, Tania Y; Hillyer, Julián F
Mosquito aging impacts a myriad of physiological processes, including digestion, flight, mating, reproductive success, and immunity. In the present study, we conducted intravital video imaging in 1, 3, 5, 10, 15 and 20-day-old Anopheles gambiae female adults to assess whether aging impacts mosquito heart physiology. We found that the heart contraction rate increases over the first 15days of adulthood and then decreases. These changes occur for both contraction directions, although aging results in a relative change in the anterograde versus retrograde contraction rates. That is, whereas for the first 5days of life the anterograde and retrograde contraction rates are similar, from day 10 to day 20 the retrograde contraction rate is higher than the anterograde contraction rate. Aging also biases the proportional directionality of heart contractions, from approximately two thirds of the time being spent contracting in the anterograde direction and two thirds of the contractions propagating anterograde during the first 5days of life to an approximately even split between anterograde and retrograde when the mosquitoes have reached 10 to 20days of age. Transcriptional analyses of crustacean cardioactive peptide (CCAP), FMRFamide, calcium-calmodulin dependent kinase II (CaMKII), pygopus, manganese-iron superoxide dismutase (MnSOD1) and vinculin by quantitative RT-PCR revealed age-associated changes in gene expression, with MnSOD1 and vinculin expression showing a declining trend with age. RNAi-based knockdown of MnSOD1 or vinculin resulted in heart physiology that trended toward the aging phenotype for every parameter that was measured, suggesting that these two genes are involved in cardiac aging. Copyright © 2017 Elsevier Ltd. All rights reserved.
Full Text Available Heart rate variability is an important risk factor for cardiovascular disease and all-cause mortality. The acetylcholine pathway plays a key role in explaining heart rate variability in humans. We assessed whether 443 genotyped and imputed common genetic variants in eight key genes (CHAT, SLC18A3, SLC5A7, CHRNB4, CHRNA3, CHRNA, CHRM2 and ACHE of the acetylcholine pathway were associated with variation in an established measure of heart rate variability reflecting parasympathetic control of the heart rhythm, the root mean square of successive differences (RMSSD of normal RR intervals. The association was studied in a two stage design in individuals of European descent. First, analyses were performed in a discovery sample of four cohorts (n = 3429, discovery stage. Second, findings were replicated in three independent cohorts (n = 3311, replication stage, and finally the two stages were combined in a meta-analysis (n = 6740. RMSSD data were obtained under resting conditions. After correction for multiple testing, none of the SNPs showed an association with RMSSD. In conclusion, no common genetic variants for heart rate variability were identified in the largest and most comprehensive candidate gene study on the acetylcholine pathway to date. Future gene finding efforts for RMSSD may want to focus on hypothesis free approaches such as the genome-wide association study.
Effects of Upper and Lower Cervical Spinal Manipulative Therapy on Blood Pressure and Heart Rate Variability in Volunteers and Patients With Neck Pain: A Randomized Controlled, Cross-Over, Preliminary Study.
Win, Ni Ni; Jorgensen, Anna Maria S; Chen, Yu Sui; Haneline, Michael T
The aims of this study were to examine autonomic nervous system responses by using heart rate variability analysis (HRV), hemodynamic parameters and numeric pain scale (NPS) when either upper (C1 and C2) or lower (C6 and C7) cervical segments were manipulated in volunteers, and whether such response would be altered in acute mechanical neck pain patients after spinal manipulative therapy (SMT). A randomized controlled, cross-over, preliminary study was conducted on 10 asymptomatic normotensive volunteers and 10 normotensive patients complaining of acute neck pain. HRV, blood pressure (BP) and heart rate (HR), and NPS were recorded after upper cervical and lower cervical segments SMT in volunteer and patient groups. The standard deviation of average normal to normal R-R intervals (SDNN) increased (83.54 ± 22 vs. 105.41 ± 20; P = .02) after upper cervical SMT. The normalized unit of high frequency (nuHF), which shows parasympathetic activity, was predominant (40.18 ± 9 vs. 46.08 ± 14) after upper cervical SMT (P = .03) with a significant decrease (109 ± 10 vs. 98 ± 5) in systolic BP (P = .002). Low frequency to high frequency (LF/HF) ratio, which shows predominance of sympathetic activity increased (1.05 ± 0.7 vs. 1.51 ± 0.5; P = .02) after lower cervical SMT in the healthy volunteers group. However, there was an increase in SDNN (70.48 ± 18 vs. 90.23 ± 20; P = .02 and 75.19 ± 16 vs 97.52 ± 22; P = .01), a decrease in LF/HF ratio (1.33 ± 0.3 vs. 0.81 ± 0.2; P = .001 and 1.22 ± 0.4 vs. 0.86 ± 0.3; P = .02), which was associated with decreased systolic BP (105 ± 10 vs. 95 ± 9; P = .01 and 102 ± 9 vs. 91 ± 10; P = .02) and NPS scores (3 ± 1 vs. 0; P = .01 and 3 ± 1 vs. 1 ± 1; P = .03) following both upper and lower cervical SMT in the patient's group. The baseline HR was 67 ± 9 vs 64 ± 5 (upper cervical) and 65 ± 7 vs 69 ± 11 (lower cervical) in both the healthy volunteer' and patient' groups. Upper cervical SMT enhances dominance of
van Someren, K A; Oliver, J E
The aim of this study was to investigate the use of incremental ergometry determined heart rate training intensities for the control of kayak ergometer and open water kayak training. Eight well-trained male kayakers completed a maximal incremental exercise test on an air-braked kayak ergometer for the determination of LT(1) (the power output at which blood lactate concentration increased by > or = 1 mmol x L(-1)), the associated heart rate (HR-LT(1)), VO(2)peak, maximal heart rate and maximal aerobic power. Subjects then performed 20 min trials of kayak ergometry (E), open water kayaking in a single kayak (K1) and open water kayaking in a four-seat kayak (K4) at HR-LT(1). During the three trials, heart rate was continuously measured, and blood lactate concentration, rating of perceived exertion (RPE) and stroke rate were determined every 5 min. In all trials, exercise at HR-LT(1) resulted in stable blood lactate concentrations and a stable RPE. Comparison of the three trials demonstrated that the only difference was for RPE, which was lower in (K4) than in (E), (p kayak ergometer and open water kayak training in both single and team boats.
Malmqvist, Lasse; Biering-Sørensen, Tor; Bartholdy, Kim
OBJECTIVES: Spinal cord injury (SCI) often results in severe dysfunction of the autonomic nervous system. C1-C8 SCI affects the supraspinal control to the heart, T1-T5 SCI affects the spinal sympathetic outflow to the heart, and T6-T12 SCI leaves sympathetic control to the heart intact. Heart rat...
Cygankiewicz, Iwona; Zareba, Wojciech; Vazquez, Rafael; Vallverdu, Montserrat; Gonzalez-Juanatey, Jose R; Valdes, Mariano; Almendral, Jesus; Cinca, Juan; Caminal, Pere; de Luna, Antoni Bayes
Abnormal heart rate turbulence (HRT) has been documented as a strong predictor of total mortality and sudden death in postinfarction patients, but data in patients with congestive heart failure (CHF) are limited. The aim of this study was to evaluate the prognostic significance of HRT for predicting mortality in CHF patients in New York Heart Association (NYHA) class II-III. In 651 CHF patients with sinus rhythm enrolled into the MUSIC (Muerte Subita en Insuficiencia Cardiaca) study, the standard HRT parameters turbulence onset (TO) and slope (TS), as well as HRT categories, were assessed for predicting total mortality and sudden death. HRT was analyzable in 607 patients, mean age 63 years (434 male), 50% of ischemic etiology. During a median follow up of 44 months, 129 patients died, 52 from sudden death. Abnormal TS and HRT category 2 (HRT2) were independently associated with increased all-cause mortality (HR: 2.10, CI: 1.41 to 3.12, P 120 ms. HRT is a potent risk predictor for both heart failure and arrhythmic death in patients with class II and III CHF.
Title: Comparison of the heart rate values and external performance is based on selected field tests determining maximal heart rate in cycling of cyclist and triathletes Objectives: Objective of thesis is to determine the values of maximal heart rate and external performance from selected field tests in cycling and compare them with one another. Methods: Three cyclist were measured in field tests and acquired results were used to create the graphs and tables. Data were obtained by cycling per...
Yilmaz, Osman; Ciftel, Murat; Ozturk, Kezban; Kilic, Omer; Kahveci, Hasan; Laloğlu, Fuat; Ceylan, Ozben
Previous studies have shown that the underlying pathophysiologic mechanism in children with breath holding may be generalised autonomic dysregulation. Thus, we performed cardiac rhythm and heart rate variability analyses using 24-hour Holter monitoring to evaluate the cardiac effects of autonomic dysregulation in children with breath-holding spells. We performed cardiac rhythm and heart rate analyses using 24-hour Holter monitors to evaluate the cardiac effects of autonomic dysregulation in children during a breath-holding spell. Our study group consisted of 68 children with breath-holding spells - 56 cyanotic type and 12 pallid type - and 39 healthy controls. Clinical and heart rate variability results were compared between each spell type - cyanotic or pallid - and the control group; significant differences (p50 ms, and square root of the mean of the sum of squares of the differences between adjacent NN intervals values were found between the pallid and cyanotic groups. Holter monitoring for 24 hours and heart rate variability parameters, particularly in children with pallid spells, are crucial for evaluation of cardiac rhythm changes.
Michael M. Knepp
Full Text Available High anxiety and poor emotion regulation have been found to function as independent causes of stress to the autonomic nervous system. The aim of this study was to further explore how these factors may interact to control heart rate variability. Fifty college students took part in a three-part cardiac recording session followed by questionnaires on trait worry and emotion regulation. An interaction for trait worry and emotion reappraisal was found on two markers of heart rate variability. Low trait worriers with high emotion reappraisal had higher vagal tone than the other three groups. This finding was across all three phases with no specific reactivity or recovery difference. Emotion suppression was not found to significantly impact vagal tone. The negative impacts of trait worry and emotion regulation on heart rate variability were found in this sample of healthy college-aged individuals. Specifically, high trait worry could have a deleterious effect on parasympathetic control of the heart. Emotion regulation skills meanwhile can function as a buffer to stress and a reliance on sympathetic control.
Pahlevan, Niema; Gharib, Morteza
The workload on the left ventricle is composed of steady and pulsatile components. Clinical investigations have confirmed that an abnormal pulsatile load plays an important role in the pathogenesis of left ventricular hypertrophy (LVH) and progression of LVH to congestive heart failure (CHF). The pulsatile load is the result of the complex dynamics of wave propagation and reflection in the compliant arterial vasculature. We hypothesize that aortic waves can be optimized to reduce the left ventricular (LV) pulsatile load. We used an in-vitro experimental approach to investigate our hypothesis. A unique hydraulic model was used for in-vitro experiments. This model has physical and dynamical properties similar to the heart-aorta system. Different compliant models of the artificial aorta were used to test the hypothesis under various aortic rigidities. Our results indicate that: i) there is an optimum heart rate that minimizes LV pulsatile power (this is in agreement with our previous computational study); ii) introducing an extra reflection site at the specific location along the aorta creates constructive wave conditions that reduce the LV pulsatile power.
Ashwal, Eran; Shinar, Shiri; Aviram, Amir; Orbach, Sharon; Yogev, Yariv; Hiersch, Liran
Intrapartum fetal heart rate (FHR) monitoring is well recommended during labor to assess fetal wellbeing. Though commonly used, the external Doppler and fetal scalp electrode monitor have significant shortcomings. Lately, non-invasive technologies were developed as possible alternatives. The objective of this study is to compare the accuracy of FHR trace using novel Electronic Uterine Monitoring (EUM) to that of external Doppler and fetal scalp electrode monitor. A comparative study conducted in a single tertiary medical center. Intrapartum FHR trace was recorded simultaneously using three different methods: internal fetal scalp electrode, external Doppler, and EUM. The latter, a multichannel electromyogram (EMG) device acquires a uterine signal and maternal and fetal electrocardiograms. FHR traces obtained from all devices during the first and second stages of labor were analyzed. Positive percent of agreement (PPA) and accuracy (by measuring root means square error between observed and predicted values) of EUM and external Doppler were both compared to internal scalp electrode monitoring. A Bland-Altman agreement plot was used to compare the differences in FHR trace between all modalities. For momentary recordings of fetal heart rate 160 bpm level of agreement, sensitivity, and specificity were also evaluated. Overall, 712,800 FHR momentary recordings were obtained from 33 parturients. Although both EUM and external Doppler highly correlated with internal scalp electrode monitoring (r2 = 0.98, p fetal heart rate 160 bpm, the PPA, sensitivity, and specificity of EUM as compared with internal fetal scalp electrode, were significantly greater than those of external Doppler (p monitoring than external Doppler. As such, it may provide a good framework for non-invasive evaluation of intrapartum FHR.
Monk, Catherine; Fifer, William P; Myers, Michael M; Bagiella, Emilia; Duong, Jimmy K; Chen, Ivy S; Leotti, Lauren; Altincatal, Arman
Women's experiences during pregnancy are predictive of variation in neurobehavioral profiles in their children. Few studies have assessed these relationships during the prenatal period. In 113 women in the 36(th) -38(th) gestational week (mean age 26.3 ± 5.4 years), electrocardiogram, blood pressure, respiration, salivary cortisol, and fetal heart rate (HR) were measured during baseline, a psychological challenge (Stroop color-word matching task), and a standardized paced breathing protocol. Subjects underwent the Structured Clinical Interview for DSM-IV prior to testing and were grouped as: depressed, co-morbid for depression and anxiety, anxiety disorder only, and control. There was a significant main effect of maternal diagnostic group on fetal HR only during the Stroop task: fetuses of women in the co-morbid group had a greater HR increase compared to controls (p breathing (p < .0001), and there was no significant difference by maternal diagnosis. For both tasks, changes in fetal HR were independent of women's concurrent cardiorespiratory activity. Finally, although cortisol was higher in the co-morbid group (p < .05), across all participants, there was a trend for maternal baseline cortisol to be positively associated with average fetal HR (p = .06). These findings indicate that variation in fetal HR reactivity-an index of emerging regulatory capacities-is likely influenced by multiple acute and chronic factors associated with women's psychobiology. Copyright © 2010 Wiley Periodicals, Inc.
Du, Na; Bai, Siqin; Oguri, Kazuo; Kato, Yoshihiro; Matsumoto, Ichie; Kawase, Harumi; Matsuoka, Toshio
The aim of the present study was to examine the effects of endurance training on heart rate (HR) recovery after exercise and cardiac autonomic nervous system (ANS) modulation in female marathon runners by comparing with untrained controls. Six female marathon runners (M group) aged 32-40 years and eight age-matched untrained females (C group) performed a maximum-effort treadmill running exercise. Maximal oxygen uptake (VO2max) was measured during the exercise with a gas analyzer connected to subjects through a face mask. Heart rate, blood pressure and blood lactate were measured before and after the exercise. Rating of perceived exertion (RPE) to the exercise was obtained immediately after the exercise. Holter ECG was recorded and analyzed with power spectral analysis of heart rate variability (HRV) to investigate the cardiac ANS modulation. The M group had significantly higher VO2max, faster HR recovery after exercise, higher Mean RR, SDRR, HF power and lower LF/HF ratio at rest compared with the C group. The M group also presented greater percent decrease of blood pressure after exercise, although their blood pressure after exercise was higher than the C group. It is suggested that endurance training induced significant alterations in cardiac ANS modulation at rest and significant acceleration of HR recovery after exercise in female marathon runners. Faster HR recovery after exercise in the female marathon runners should result from their higher levels of HRV, higher aerobic capacity and exaggerated blood pressure response to exercise compared with untrained controls. Key PointsThe effects of endurance training on HR recovery after exercise and cardiac ANS modulation were investigated in female marathon runners by comparing with untrained controls.Time and frequency domain analysis of HRV was used to investigate cardiac ANS modulation.As compared with untrained controls, the female marathon runners showed faster HR recovery after exercise, which should result
Lehrer, Paul M; Gevirtz, Richard
In recent years there has been substantial support for heart rate variability biofeedback (HRVB) as a treatment for a variety of disorders and for performance enhancement (Gevirtz, 2013). Since conditions as widely varied as asthma and depression seem to respond to this form of cardiorespiratory feedback training, the issue of possible mechanisms becomes more salient. The most supported possible mechanism is the strengthening of homeostasis in the baroreceptor (Vaschillo et al., 2002; Lehrer et al., 2003). Recently, the effect on the vagal afferent pathway to the frontal cortical areas has been proposed. In this article, we review these and other possible mechanisms that might explain the positive effects of HRVB.
Eva Mlyneková; Marko Halo; Miroslav Maršálek; Lucie Starostová
In our work, we analyzed the effect of training load on the heart rate of horses in a simulated load by the loading regulator for horse motion Horse Gym 2000. In the experiment were observed 8 Slovak Warmblood horses (3 mares, 4 geldings, 1 stallion) aged 6-10 years. The experiment was divided into two parts after three weeks. The speed of the tested horses was 4.9 km/h in the first part of experiment, in the second part was the speed 5.2 km/h with a gradual uphill up to 7 %. The tested horse...
Full Text Available The aim of the present study is to obtain a highly objective automatic fetal heart rate (FHR diagnosis. The neural network software was composed of three layers with the back propagation, to which 8 FHR data, including sinusoidal FHR, were input and the system was educated by the data of 20 cases with a known outcome. The output was the probability of a normal, intermediate, or pathologic outcome. The neural index studied prolonged monitoring. The neonatal states and the FHR score strongly correlated with the outcome probability. The neural index diagnosis was correct. The completed software was transferred to other computers, where the system function was correct.
Paul M Lehrer
Full Text Available In recent years there has been substantial support for Heart Rate Variability Biofeedback (HRVB as a treatment for a variety of disorders and for performance enhancement (Gevirtz, 2013. Since conditions as widely varied as asthma and depression seem to respond to this form of cardiorespiratory feedback training, the issue of possible mechanisms becomes more salient. The most supported possible mechanism is the strengthening of homeostasis in the barorecptor (Vashillo, et al, 2002; Lehrer, et al, 2003. Recently, the effect on the vagal afferent pathway to the frontal cortical areas has been proposed. In this article, we review these and other possible mechanisms that might explain the positive effects of HRVB.
Cascaval, Radu C.; D'Apice, Ciro; D'Arienzo, Maria Pia
We consider a 1-D model for the simulation of the blood flow in the cardiovascular system. As inflow condition we consider a model for the aortic valve. The opening and closing of the valve is dynamically determined by the pressure difference between the left ventricular and aortic pressures. At the outflow we impose a peripheral resistance model. To approximate the solution we use a numerical scheme based on the discontinuous Galerkin method. We also considering a variation in heart rate and terminal reflection coefficient due to monitoring of the pressure in the network.
Blanksby, B A; Reidy, P W
Ten competitive ballroom dance couples performed simulated competitive sequences of Modern and Latin American dance. Heart rate was telemetered during the dance sequences and related to direct measures of oxygen uptake and heart rate obtained while walking on a treadmill. Linear regression was employed to estimate gross and net energy expenditures of the dance sequences. A multivariate analysis of variance with repeated measures on the dance factor was applied to the data to test for interaction and main effects on the sex and dance factors. Overall mean heart rate values for the Modern dance sequence were 170 beats.min-1 and 173 beats.min-1 for males and females respectively. During the Latin American sequence mean overall heart rate for males was 168 beats.min-1 and 177 beats.min-1 for females. Predicted mean gross values of oxygen consumption for the males were 42.8 +/- 5.7 ml.kg-1 min-1 and 42.8 +/- 6.9 ml.kg-1 min-1 for the Modern and Latin American sequences respectively. Corresponding gross estimates of oxygen consumption for the females were 34.7 +/- 3.8 ml.kg-1 min-1 and 36.1 +/- 4.1 ml.kg-1 min-1. Males were estimated to expand 54.1 +/- 8.1 kJ.min-1 of energy during the Modern sequence and 54.0 +/- 9.6 kJ.min-1 during the Latin American sequence, while predicted energy expenditure for females was 34.7 +/- 3.8 kJ.min-1 and 36.1 +/- 4.1 kJ.min-1 for Modern and Latin American dance respectively. The results suggested that both males and females were dancing at greater than 80% of their maximum oxygen consumption. A significant difference between males and females was observed for predicted gross and net values of oxygen consumption (in L.min-1 and ml.kg-1 min-1). PMID:3167503
Susi, Louis; Reader, Al; Nusstein, John; Beck, Mike; Weaver, Joel; Drum, Melissa
The authors, using a crossover design, randomly administered, in a single-blind manner, 3 primary intraosseous injections to 61 subjects using: the Wand local anesthetic system at a deposition rate of 45 seconds (fast injection); the Wand local anesthetic system at a deposition rate of 4 minutes and 45 seconds (slow injection); a conventional syringe injection at a deposition rate of 4 minutes and 45 seconds (slow injection), in 3 separate appointments spaced at least 3 weeks apart. A pulse oximeter measured heart rate (pulse). The results demonstrated the mean maximum heart rate was statistically higher with the fast intraosseous injection (average 21 to 28 beats/min increase) than either of the 2 slow intraosseous injections (average 10 to 12 beats/min increase). There was no statistically significant difference between the 2 slow injections. We concluded that an intraosseous injection of 1.4 mL of 2% lidocaine with 1 : 100,000 epinephrine with the Wand at a 45-second rate of anesthetic deposition resulted in a significantly higher heart rate when compared with a 4-minute and 45-second anesthetic solution deposition using either the Wand or traditional syringe.
den Hoed, Marcel; Eijgelsheim, Mark; Esko, Tõnu; Brundel, Bianca J J M; Peal, David S; Evans, David M; Nolte, Ilja M; Segrè, Ayellet V; Holm, Hilma; Handsaker, Robert E; Westra, Harm-Jan; Johnson, Toby; Isaacs, Aaron; Yang, Jian; Lundby, Alicia; Zhao, Jing Hua; Kim, Young Jin; Go, Min Jin; Almgren, Peter; Bochud, Murielle; Boucher, Gabrielle; Cornelis, Marilyn C; Gudbjartsson, Daniel; Hadley, David; van der Harst, Pim; Hayward, Caroline; den Heijer, Martin; Igl, Wilmar; Jackson, Anne U; Kutalik, Zoltán; Luan, Jian'an; Kemp, John P; Kristiansson, Kati; Ladenvall, Claes; Lorentzon, Mattias; Montasser, May E; Njajou, Omer T; O'Reilly, Paul F; Padmanabhan, Sandosh; St Pourcain, Beate; Rankinen, Tuomo; Salo, Perttu; Tanaka, Toshiko; Timpson, Nicholas J; Vitart, Veronique; Waite, Lindsay; Wheeler, William; Zhang, Weihua; Draisma, Harmen H M; Feitosa, Mary F; Kerr, Kathleen F; Lind, Penelope A; Mihailov, Evelin; Onland-Moret, N Charlotte; Song, Ci; Weedon, Michael N; Xie, Weijia; Yengo, Loic; Absher, Devin; Albert, Christine M; Alonso, Alvaro; Arking, Dan E; de Bakker, Paul I W; Balkau, Beverley; Barlassina, Cristina; Benaglio, Paola; Bis, Joshua C; Bouatia-Naji, Nabila; Brage, Søren; Chanock, Stephen J; Chines, Peter S; Chung, Mina; Darbar, Dawood; Dina, Christian; Dörr, Marcus; Elliott, Paul; Felix, Stephan B; Fischer, Krista; Fuchsberger, Christian; de Geus, Eco J C; Goyette, Philippe; Gudnason, Vilmundur; Harris, Tamara B; Hartikainen, Anna-Liisa; Havulinna, Aki S; Heckbert, Susan R; Hicks, Andrew A; Hofman, Albert; Holewijn, Suzanne; Hoogstra-Berends, Femke; Hottenga, Jouke-Jan; Jensen, Majken K; Johansson, Asa; Junttila, Juhani; Kääb, Stefan; Kanon, Bart; Ketkar, Shamika; Khaw, Kay-Tee; Knowles, Joshua W; Kooner, Angrad S; Kors, Jan A; Kumari, Meena; Milani, Lili; Laiho, Päivi; Lakatta, Edward G; Langenberg, Claudia; Leusink, Maarten; Liu, Yongmei; Luben, Robert N; Lunetta, Kathryn L; Lynch, Stacey N; Markus, Marcello R P; Marques-Vidal, Pedro; Mateo Leach, Irene; McArdle, Wendy L; McCarroll, Steven A; Medland, Sarah E; Miller, Kathryn A; Montgomery, Grant W; Morrison, Alanna C; Müller-Nurasyid, Martina; Navarro, Pau; Nelis, Mari; O'Connell, Jeffrey R; O'Donnell, Christopher J; Ong, Ken K; Newman, Anne B; Peters, Annette; Polasek, Ozren; Pouta, Anneli; Pramstaller, Peter P; Psaty, Bruce M; Rao, Dabeeru C; Ring, Susan M; Rossin, Elizabeth J; Rudan, Diana; Sanna, Serena; Scott, Robert A; Sehmi, Jaban S; Sharp, Stephen; Shin, Jordan T; Singleton, Andrew B; Smith, Albert V; Soranzo, Nicole; Spector, Tim D; Stewart, Chip; Stringham, Heather M; Tarasov, Kirill V; Uitterlinden, André G; Vandenput, Liesbeth; Hwang, Shih-Jen; Whitfield, John B; Wijmenga, Cisca; Wild, Sarah H; Willemsen, Gonneke; Wilson, James F; Witteman, Jacqueline C M; Wong, Andrew; Wong, Quenna; Jamshidi, Yalda; Zitting, Paavo; Boer, Jolanda M A; Boomsma, Dorret I; Borecki, Ingrid B; van Duijn, Cornelia M; Ekelund, Ulf; Forouhi, Nita G; Froguel, Philippe; Hingorani, Aroon; Ingelsson, Erik; Kivimaki, Mika; Kronmal, Richard A; Kuh, Diana; Lind, Lars; Martin, Nicholas G; Oostra, Ben A; Pedersen, Nancy L; Quertermous, Thomas; Rotter, Jerome I; van der Schouw, Yvonne T; Verschuren, W M Monique; Walker, Mark; Albanes, Demetrius; Arnar, David O; Assimes, Themistocles L; Bandinelli, Stefania; Boehnke, Michael; de Boer, Rudolf A; Bouchard, Claude; Caulfield, W L Mark; Chambers, John C; Curhan, Gary; Cusi, Daniele; Eriksson, Johan; Ferrucci, Luigi; van Gilst, Wiek H; Glorioso, Nicola; de Graaf, Jacqueline; Groop, Leif; Gyllensten, Ulf; Hsueh, Wen-Chi; Hu, Frank B; Huikuri, Heikki V; Hunter, David J; Iribarren, Carlos; Isomaa, Bo; Jarvelin, Marjo-Riitta; Jula, Antti; Kähönen, Mika; Kiemeney, Lambertus A; van der Klauw, Melanie M; Kooner, Jaspal S; Kraft, Peter; Iacoviello, Licia; Lehtimäki, Terho; Lokki, Marja-Liisa L; Mitchell, Braxton D; Navis, Gerjan; Nieminen, Markku S; Ohlsson, Claes; Poulter, Neil R; Qi, Lu; Raitakari, Olli T; Rimm, Eric B; Rioux, John D; Rizzi, Federica; Rudan, Igor; Salomaa, Veikko; Sever, Peter S; Shields, Denis C; Shuldiner, Alan R; Sinisalo, Juha; Stanton, Alice V; Stolk, Ronald P; Strachan, David P; Tardif, Jean-Claude; Thorsteinsdottir, Unnur; Tuomilehto, Jaako; van Veldhuisen, Dirk J; Virtamo, Jarmo; Viikari, Jorma; Vollenweider, Peter; Waeber, Gérard; Widen, Elisabeth; Cho, Yoon Shin; Olsen, Jesper V; Visscher, Peter M; Willer, Cristen; Franke, Lude; Erdmann, Jeanette; Thompson, John R; Pfeufer, Arne; Sotoodehnia, Nona; Newton-Cheh, Christopher; Ellinor, Patrick T; Stricker, Bruno H Ch; Metspalu, Andres; Perola, Markus; Beckmann, Jacques S; Smith, George Davey; Stefansson, Kari; Wareham, Nicholas J; Munroe, Patricia B; Sibon, Ody C M; Milan, David J; Snieder, Harold; Samani, Nilesh J; Loos, Ruth J F
Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously established loci. Experimental downregulation of gene expression in Drosophila melanogaster and Danio rerio identified 20 genes at 11 loci that are relevant for heart rate regulation and highlight a role for genes involved in signal transmission, embryonic cardiac development and the pathophysiology of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate-increasing and heart rate-decreasing variants associate with risk of atrial fibrillation. Our findings provide fresh insights into the mechanisms regulating heart rate and identify new therapeutic targets.
Full Text Available Background: Pregnancy increases the risk of developing anxiety that may affect the fetus. Yoga is considered as an alternative therapy to reduce anxiety, blood pressure, and fetal heart rate. Objective: This study aimed to examine the effect of prenatal yoga on anxiety, blood pressure, and fetal heart rate in primigravida mothers. Methods: There were 39 primigravida mothers selected using purposive sampling, which divided to be an experiment group with four-times prenatal yoga and eight-times prenatal yoga, and a control group. The Hamilton Rating Scale For Anxiety (HRSA was used. Data were analyzed using One way ANOVA and MANOV A. Results: There was a statistically significant difference of prenatal yoga on anxiety (P=0.005, systolic blood pressure (P=0.045, and fetal heart rate (P=0.010. However, there was no significant difference of prenatal yoga on diastolic blood pressure with p-value 0.586 (>0.05 Conclusion: There were significant effects of prenatal yoga on anxiety level, systolic blood pressure, and the fetal heart rates in primigravida mothers. The findings of this study can be an alternative treatment for midwife to deal with anxiety during pregnancy, and an input on the class program of pregnant women to improve the quality of maternal and fetal health.
Horiguchi, Ayaka; Takatsu, Hiroaki; Ohno, Wataru; Ozeki, Osamu
We studied the evaluation for the intensity of stress of students in lesson using heart rate variability. Heart rate of many students were measured simultaneously by developed portable measurement systems. Heart rate variability data suggests that many students have more stress in normal dictation lesson then video lesson using difficult subject.
van den Berg, Marten E.; Warren, Helen R; Cabrera, Claudia P; Verweij, Niek; Mifsud, Borbala; Haessler, Jeffrey; Bihlmeyer, Nathan A.; Fu, Yi-Ping; Weiss, Stefan; Lin, Henry J.; Grarup, Niels; Li-Gao, Ruifang; Pistis, Giorgio; Shah, Nabi; Brody, Jennifer A.; Mueller-Nurasyid, Martina; Lin, Honghuang; Mei, Hao; Smith, Albert V.; Lyytikainen, Leo-Pekka; Hall, Leanne M; van Setten, Jessica; Trompet, Stella; Prins, Bram P.; Isaacs, Aaron; Radmanesh, Farid; Marten, Jonathan; Entwistle, Aiman; Kors, Jan A.; Silva, Claudia T; Alonso, Alvaro; Bis, Joshua C.; de Boer, Rudolf; de Haan, Hugoline G; de Mutsert, Renee; Dedoussis, George; Dominiczak, Anna F.; Doney, Alex S. F.; Ellinor, Patrick T.; Eppinga, Ruben N.; Felix, Stephan B.; Guo, Xiuqing; Hagemeijer, Yanick; Hansen, Torben; Harris, Tamara B.; Heckbert, Susan R.; Huang, Paul L.; Hwang, Shih-Jen; Kahonen, Mika; Kanters, Jorgen K.; Kolcic, Ivana; Launer, Lenore J.; Li, Man; Yao, Jie; Linneberg, Allan; Liu, Simin; MacFarlane, Peter W.; Mangino, Massimo; Morris, Andrew D.; Mulas, Antonella; Murray, Alison D.; Nelson, Christopher P.; Orru, Marco; Padmanabhan, Sandosh; Peters, Annette; Porteous, David J.; Poulter, Neil; Psaty, Bruce M.; Qi, Lihong; Raitakari, Olli T.; Rivadeneira, Fernando; Roselli, Carolina; Rudan, Igor; Sattar, Naveed; Sever, Peter; Sinner, Moritz F.; Soliman, Elsayed Z.; Spector, Timothy D.; Stanton, Alice V.; Stirrups, Kathleen E; Taylor, Kent D.; Tobin, Martin D.; Uitterlinden, Andre; Vaartjes, Ilonca; Hoes, Arno W.; van der Meer, Peter; Voelker, Uwe; Waldenberger, Melanie; Xie, Zhijun; Zoledziewska, Magdalena; Tinker, Andrew; Polasek, Ozren; Rosand, Jonathan; Jamshidi, Yalda; Duijn, Cornelia Mvan; Zeggini, Eleftheria; Jukema, Wouter J.; Asselbergs, Folkert W.; Samani, Nilesh J.; Lehtimaki, Terho; Gudnason, Vilmundur; Wilson, James G.; Lubitz, Steven A.; Kaeaeb, Stefan; Sotoodehnia, Nona; Caulfield, Mark J.; Palmer, Colin N. A.; Sanna, Serena; Mook-Kanamori, Dennis O.; Deloukas, Panos; Pedersen, Oluf; Rotter, Jerome I.; Doerr, Marcus; O'Donnell, Chris J.; Hayward, Caroline; Arking, Dan E.; Kooperberg, Charles; van der Harst, Pim; Eijgelsheim, Mark; Stricker, Bruno H.; Munroe, Patricia B.
Resting heart rate is a heritable trait, and an increase in heart rate is associated with increased mortality risk. Genome-wide association study analyses have found loci associated with resting heart rate, at the time of our study these loci explained 0.9% of the variation. This study aims to
M.E. van den Berg (Marten); H. Warren (Helen); Cabrera, C.P. (Claudia P.); Verweij, N. (Niek); Mifsud, B. (Borbala); J. Haessler (Jeff); N.A. Bihlmeyer (Nathan A.); Fu, Y.-P. (Yi-Ping); Weiss, S. (Stefan); Lin, H.J. (Henry J.); N. Grarup (Niels); Li-Gao, R. (Ruifang); G. Pistis (Giorgio); N. Shah (Nisha); J.A. Brody (Jennifer A.); Müller-Nurasyid, M. (Martina); H. Lin (Honghuang); H. Mei (Hao); A.V. Smith (Albert V.); L.-P. Lyytikäinen (Leo-Pekka); L.M. Hall (Leanne M.); J. van Setten (Jessica); S. Trompet (Stella); Prins, B.P. (Bram P.); A.J. Isaacs (Aaron); F. Radmanesh (Farid); J. Marten (Jonathan); Entwistle, A. (Aiman); J.A. Kors (Jan); C.T. Silva (Claudia Tamar); A. Alonso (Alvaro); J.C. Bis (Joshua); R.A. de Boer (Rudolf); H.G. De Haan (Hugoline G.); R. de Mutsert (Reneé); G.V. Dedoussis (George); A. Dominiczak (Anna); A.S.F. Doney (Alex); P.T. Ellinor (Patrick); Eppinga, R.N. (Ruben N.); S.B. Felix (Stephan); X. Guo (Xiuqing); Hagemeijer, Y. (Yanick); T. Hansen (T.); T.B. Harris (Tamara); S.R. Heckbert (Susan); Huang, P.L. (Paul L.); S.-J. Hwang (Shih-Jen); M. Kähönen (Mika); J.K. Kanters; I. Kolcic (Ivana); L.J. Launer (Lenore); M. Li (Man); J. Yao (Jiefen); A. Linneberg (Allan); Liu, S. (Simin); P.W. MacFarlane (Peter); M. Mangino (Massimo); Morris, A.D. (Andrew D.); Mulas, A. (Antonella); Murray, A.D. (Alison D.); C.P. Nelson (Christopher P.); M. Orrù (Marco); S. Padmanabhan (Sandosh); A. Peters (Annette); D.J. Porteous (David J.); N.R. Poulter (Neil); B.M. Psaty (Bruce M.); L. Qi (Lihong); Raitakari, O.T. (Olli T.); Rivadeneira, F. (Fernando); Roselli, C. (Carolina); I. Rudan (Igor); N. Sattar (Naveed); P. Sever (Peter); M.F. Sinner (Moritz); E.Z. Soliman (Elsayed); T.D. Spector (Timothy); A. Stanton (Alice); K. Stirrups (Kathy); K.D. Taylor (Kent); M.D. Tobin (Martin); A.G. Uitterlinden (André); I. Vaartjes (Ilonca); A.W. Hoes (Arno); van der Meer, P. (Peter); U. Völker (Uwe); Waldenberger, M. (Melanie); Xie, Z. (Zhijun); M. Zoledziewska (Magdalena); Tinker, A. (Andrew); O. Polasek (Ozren); J. Rosand (Jonathan); Jamshidi, Y. (Yalda); C.M. van Duijn (Cornelia); E. Zeggini (Eleftheria); J.W. Jukema (Jan Wouter); F.W. Asselbergs (Folkert); N.J. Samani (Nilesh); T. Lehtimäki (Terho); V. Gudnason (Vilmundur); J.F. Wilson (James); Lubitz, S.A. (Steven A.); S. Kääb (Stefan); N. Sotoodehnia (Nona); M. Caulfield (Mark); C.N.A. Palmer (Colin); S. Sanna (Serena); D.O. Mook-Kanamori (Dennis); Deloukas, P. (Panos); O. Pedersen (Oluf); J.I. Rotter (Jerome I.); M. Dörr (Marcus); C.J. O'Donnell (Christopher J.); C. Hayward (Caroline); D.E. Arking (Dan); C. Kooperberg (Charles); van der Harst, P. (Pim); M. Eijgelsheim (Mark); B.H.Ch. Stricker (Bruno); P. Munroe (Patricia)
markdownabstractResting heart rate is a heritable trait, and an increase in heart rate is associated with increased mortality risk. Genome-wide association study analyses have found loci associated with resting heart rate, at the time of our study these loci explained 0.9% of the variation. This
van den Berg, Marten E; Warren, Helen R; Cabrera, Claudia P
Resting heart rate is a heritable trait, and an increase in heart rate is associated with increased mortality risk. Genome-wide association study analyses have found loci associated with resting heart rate, at the time of our study these loci explained 0.9% of the variation. This study aims to di...
Stone, Michael H.; And Others
A study of effects of squatting exercise on heart rate and blood lactate levels in trained and untrained males indicated that trained subjects performed more work and had higher heart rates and lactate levels at exhaustion untrained subjects, though heart rate and lactate levels were lower for trained subjects at a given bar mass or submaximal…
Laurson, Kelly R.; Brown, Dale D.; Cullen, Robert W.; Dennis, Karen K.
This study examined how activity type influenced heart rates and time spent in target heart rate zones of high school students participating in physical education classes. Significantly higher average heart rates existed for fitness (142 plus or minus 24 beats per minute [bpm]) compared to team (118 plus or minus 24 bpm) or individual (114 plus or…
Godinez, Angelica; Ayzenberg, Ruthie; Liston, Dorian B.; Stone, Leland S.
Aerospace and applied environments commonly expose pilots and astronauts to G-loading and vibration, alone and in combination, with well-known sensorimotor (Cohen, 1970) and performance consequences (Adelstein et al., 2008). Physiological variables such as heart rate (HR) and breathing rate (BR) have been shown to increase with G-loading (Yajima et al., 1994) and vibration (e.g. Guignard, 1965, 1985) alone. To examine the effects of G-loading and vibration, alone and in combination, we measured heart rate and breathing rate under aerospace-relevant conditions (G-loads of 1 Gx and 3.8 Gx; vibration of 0.5 gx at 8, 12, and 16 Hz).
O'Donnell, Emma; Landolt, Kathleen; Hazi, Agnes; Dragano, Nico; Wright, Bradley J
We assessed in an experimental design whether the stress response towards a work task was moderated by the autonomy to choose a break during the assigned time to complete the task. This setting is defined in accordance with the theoretical framework of the job-demand-control (JDC) model of work related stress. The findings from naturalistic investigations of a stress-buffering effect of autonomy (or 'buffer hypothesis') are equivocal and the experimental evidence is limited, especially with relation to physiological indices of stress. Our objective was to investigate if increased autonomy in a particular domain (break time control) was related with adaptive physiology using objective physiological markers of stress; heart rate variability (HRV) and salivary alpha amylase (sAA). We used a within-subject design and the 60 female participants were randomly assigned to an autonomy (free timing of break) and standard conditions (fixed timing of break) of a word processing task in a simulated office environment in a random order. Participants reported increased perceptions of autonomy, no difference in demand and performed worse in the task in the break-time autonomy versus the standard condition. The results revealed support for the manipulation of increased autonomy, but in the opposing direction. Increased autonomy was related with dysregulated physiological reactivity, synonymous with typical increased stress responses. Potentially, our findings may indicate that autonomy is not necessary a resource but could become an additional stressor when it adds additional complexity while the amount of work (demands) remains unchanged. Further, our findings underscore the need to collect objective physiological evidence of stress to supplement self-reported information. Self-report biases may partially explain the inconsistent findings with the buffer hypothesis. Copyright © 2014 Elsevier Ltd. All rights reserved.
Kresh, J Y; Izrailtyan, I
The capacity of self-organized systems to adapt is embodied in the functional organization of intrinsic control mechanisms. Evolution in functional complexity of heart rate variability (HRV) was used as measure of the capacity of the transplanted heart to express newly emergent regulatory order. In a cross-sectional study of 100 patients after (0-10 yr) heart transplantation (HTX), heart rate dynamics were assessed using pointwise correlation dimension (PD2) analysis. A new observation is that, commencing with the acute event of allograft transplantation, the dynamics of rhythm formation proceed through complex phase transitions. At implantation, the donor heart manifested metronome-like chronotropic behavior (PD2 approximately 1.0). At 11-100 days, dimensional complexity of HRV reached a peak (PD2 approximately 2.0) associated with resurgence in the high-frequency component (0.15-0.5 Hz) of the power spectral density. Subsequent dimensional loss to PD2 approximately 1.0 at 20-30 mo after HTX was followed by a progressive near-linear gain in system complexity, reaching PD2 approximately 3.0 7-10 yr after HTX. The "dynamic reorganization" in the allograft rhythm-generating system, seen in the first 100 days, is a manifestation of the adaptive capacity of intrinsic control mechanisms. The loss of HRV 2 yr after HTX implies a withdrawal of intrinsic autonomic control and/or development of an entrained dynamic pattern characteristic of extrinsic sympathetic input. The subsequent long-term progressive rise in dimensional complexity of HRV can be attributed to the restoration of a functional order patterning parasympathetic control. The recognition that the decentralized heart can restitute the multidimensional state space of HR generator dynamics independent of external autonomic signaling may provide a new perspective on principles that constitute homeodynamic regulation.
Mateo, Javier; Laguna, Pablo
The time-domain signals representing the heart rate variability (HRV) in the presence of an ectopic beat exhibit a sharp transient at the position of the ectopic beat, which corrupts the signal, particularly the power spectral density (PSD) of the HRV. Consequently, there is a need for correction of this type of beat prior to any HRV analysis. This paper deals with the PSD estimation of the HRV by means of the heart timing (HT) signal when ectopic beats are present. These beat occurrence times are modeled from a generalized, continuous time integral pulse frequency modulation model and, from this point of view, a specific method for minimizing the effect of the presence of ectopic beats is presented to work together with the HT signal. By using both, a white noise driven autoregressive model of the HRV signal with artificially introduced ectopic beats and actual heart rate series including ectopic beats, the more usual methods of HRV spectral estimation are compared. Results of the PSD estimation error function of the number of ectopic beats are presented. These results demonstrate that the proposed method has one order of magnitude lower error than usual ectopic beats removal strategies in preserving PSD, thus, this strategy better recovers the original clinical indexes of interest.
Pfister, Roman; Michels, Guido; Sharp, Stephen J; Luben, Robert; Wareham, Nick J; Khaw, Kay-Tee
Increasing levels of resting heart rate are associated with increased risk of developing hypertension and cardiovascular disease, and seem to play a role in the progression of heart failure. The shape of the association between resting heart rate and risk of developing heart failure has not been examined in healthy individuals of the general population. Hazard ratios (HRs) of heart failure comparing categories of resting heart rate [51-60 b.p.m. (reference), 61-70 b.p.m., 71-80 b.p.m., 81-90 b.p.m., and 91-100 b.p.m.] were calculated in apparently healthy men (9805) and women (12 321) aged 39-79 participating in the 'European Prospective Investigation into Cancer and Nutrition' (EPIC) study in Norfolk. During a mean follow-up of 12.9 years, 1356 incident cases of heart failure occurred. In participants without potential heart rate-modifying medication, age- and sex-adjusted incidence rates of heart failure were 3.3, 3.7, 4.0, 5.1, and 5.5 per 1000 person-years for increasing categories of resting heart rate; compared with the reference category, HRs and 95% confidence intervals (CI) for increasing categories of resting heart rate were 1.08 (0.88-1.34), 1.17 (0.94-1.46), 1.39 (1.08-1.79), and 1.42 (1.00-2.03), respectively, in multivariable analysis adjusting for age, sex, body mass index, systolic blood pressure, prevalent diabetes, cholesterol concentration, social class, educational level, smoking, and physical activity. Within the reference range of resting heart rate (50-100 b.p.m.) each 10 b.p.m. increase was associated with an 11% increase in hazard of heart failure in multivariable analysis. The results did not change materially after adjusting for myocardial infarction and coronary heart disease events during follow up (1.12, 1.06-1.18). Resting heart rate shows a graded association with hazard of heart failure in apparently healthy men and women which is not mediated by coronary heart disease. Further study is needed to examine the underlying mechanisms.
O'Mara, M Teague; Rikker, Sebastian; Wikelski, Martin; Ter Maat, Andries; Pollock, Henry S; Dechmann, Dina K N
Reduction in metabolic rate and body temperature is a common strategy for small endotherms to save energy. The daily reduction in metabolic rate and heterothermy, or torpor, is particularly pronounced in regions with a large variation in daily ambient temperature. This applies most strongly in temperate bat species (order Chiroptera), but it is less clear how tropical bats save energy if ambient temperatures remain high. However, many subtropical and tropical species use some daily heterothermy on cool days. We recorded the heart rate and the body temperature of free-ranging Pallas' mastiff bats ( Molossus molossus ) in Gamboa, Panamá, and showed that these individuals have low field metabolic rates across a wide range of body temperatures that conform to high ambient temperature. Importantly, low metabolic rates in controlled respirometry trials were best predicted by heart rate, and not body temperature . Molossus molossus enter torpor-like states characterized by low metabolic rate and heart rates at body temperatures of 32°C, and thermoconform across a range of temperatures. Flexible metabolic strategies may be far more common in tropical endotherms than currently known.
Yoshihisa, Akiomi; Suzuki, Satoshi; Takiguchi, Mai; Shimizu, Takeshi; Abe, Satoshi; Sato, Takamasa; Yamaki, Takayoshi; Sugimoto, Koichi; Kunii, Hiroyuki; Nakazato, Kazuhiko; Suzuki, Hitoshi; Saitoh, Shu-ichi; Takeishi, Yasuchika
Sleep-disordered breathing (SDB) is associated with adverse outcomes in patients with chronic heart failure (CHF). Additionally, heart rate turbulence (HRT) reflects changes in the sinus cycle length of baroreceptor in response to hemodynamic fluctuations after ventricular premature beat. Recent studies have suggested that HRT as a marker of vagal activity has a predictive value of poor prognosis in CHF patients. However, little is known about the relationship between SDB and HRT in CHF patients. In this study, 75 patients with CHF were enrolled. We simultaneously performed Holter ECG during a 24-hr period and portable sleep monitoring at nighttime, and determined the respiratory disturbance index (RDI), HRT (turbulence onset (TO) and turbulence slope (TS)) during that 24-hr period. These patients were divided into two groups based on the presence of severe SDB: Group A (RDI≥30, n = 17) and Group B (RDICHF patients.
Gribble, Matthew O; Cheng, Alan; Berger, Ronald D; Rosman, Lori; Guallar, Eliseo
Mercury affects the nervous system and has been implicated in altering heart rhythm and function. We sought to better define its role in modulating heart rate variability, a well-known marker of cardiac autonomic function. This is a systematic review study. We searched PubMed, Embase, TOXLINE, and DART databases without language restriction. We report findings as a qualitative systematic review because heterogeneity in study design and assessment of exposures and outcomes across studies, as well as other methodological limitations of the literature, precluded a quantitative meta-analysis. We identified 12 studies of mercury exposure and heart rate variability in human populations (ten studies involving primarily environmental methylmercury exposure and two studies involving occupational exposure to inorganic mercury) conducted in Japan, the Faroe Islands, Canada, Korea, French Polynesia, Finland, and Egypt. The association of prenatal mercury exposure with lower high-frequency band scores (thought to reflect parasympathetic activity) in several studies, in particular the inverse association of cord blood mercury levels with the coefficient of variation of the R-R intervals and with low-frequency and high-frequency bands at 14 years of age in the Faroe Islands birth cohort study, suggests that early mercury exposure could have a long-lasting effect on cardiac parasympathetic activity. Studies with later environmental exposures to mercury in children or in adults were heterogeneous and did not show consistent associations. The evidence was too limited to draw firm causal inferences. Additional research is needed to elucidate the effects of mercury on cardiac autonomic function, particularly as early-life exposures might have lasting impacts on cardiac parasympathetic function.
Sletten, Julie; Kiserud, Torvid; Kessler, Jörg
The new Holter monitoring technology enables long-term electrocardiographic recording of the fetal heart rate without discomfort for the mother. The aim of the study was to assess the feasibility of a fetal Holter monitor. This technology was further used to study fetal heart rate outside the hospital setting during normal daily activities and to test the hypothesis that uterine activity during pregnancy influences fetal heart rate. Prospective observational study including 12 healthy pregnant women at 20-40 weeks of gestation. Data were collected using the Monica AN24 system. Outcome measures were fetal heart rate, maternal heart rate, and uterine activity categorized according to the strength of the electrohysterographic signal. The recordings had a median length of 18.8 h, and fetal heart rate and maternal heart rate were obtained with success rates of 73.1 and 99.9%, respectively. Uterine activity was found to affect fetal heart rate in all participants. Compared with the basal tone and mild levels of uterine activity, moderate and strong levels of uterine activity were associated with increases in fetal heart rate of 4.0 and 5.7 beats/min, respectively. At night, the corresponding increases were 4.9 and 7.6 beats/min. Linear correlations were found between maternal heart rate and fetal heart rate in 11 of the 12 cases, with a mean coefficient beta of 0.189. Both maternal heart rate and fetal heart rate exhibited a diurnal pattern, with lower heart rates being recorded at night. Uterine activity during pregnancy is associated with a graded response in fetal heart rate and may represent a physiological challenge for the development and adaptation of the fetal cardiovascular system. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.
Hansen, Anita Lill; Johnsen, Bjørn Helge; Thornton, David; Waage, Leif; Thayer, Julian F
The aim of the present study was to investigate whether the four facets of Hare's Psychopathy Checklist-Revised (PCL-R; Hare, 1991; Bolt, Hare, Vitale, & Newman, 2004) were related to physiological and cognitive mechanisms. Fifty-three male prisoners participated in this study. Physiological responses were measured as heart rate variability (HRV) and heart rate (HR). Cognitive functions were measured using a continuous performance test (CPT; California Computerized Assessment Package, Abbreviated version) and a working memory test (WMT); based on Baddeley & Hitch (1974). The regression analysis of the HRV revealed that the interpersonal facet explained most of the variance during baseline (28%), CPT (16%), and WMT (12%). This was also true for the HR data during baseline (28%), CPT (20%), WMT (10%), and recovery (13%). The antisocial facet explained 10% of the variance only during baseline. Subjects scoring high compared to low on the interpersonal facet also showed better cognitive functioning. The study suggests that the different facets were differently associated with both physiological and cognitive functions.
Malińska, Marzena; Zużewicz, Krystyna; Bugajska, Joanna; Grabowski, Andrzej
The goal of the study was assessment of the hour-long training involving handling virtual environment (sVR) and watching a stereoscopic 3D movie on the mechanisms of autonomic heart rate (HR) regulation among the subjects who were not predisposed to motion sickness. In order to exclude predispositions to motion sickness, all the participants (n=19) underwent a Coriolis test. During an exposure to 3D and sVR the ECG signal was continuously recorded using the Holter method. For the twelve consecutive 5-min epochs of ECG signal, the analysis of heart rate variability (HRV) in time and frequency domains was conducted. After 30 min from the beginning of the training in handling the virtual workstation a significant increase in LF spectral power was noted. The values of the sympathovagal LF/HF index while sVR indicated a significant increase in sympathetic predominance in four time intervals, namely between the 5th and the 10th minute, between the 15th and the 20th minute, between the 35th and 40th minute and between the 55th and the 60th minute of exposure.
Fortrat, Jacques-Olivier; Baum, Charlotte; Jeanguillaume, Christian; Custaud, Marc-Antoine
Heart rate spontaneously fluctuates despite homeostatic regulatory mechanisms to stabilize it. Harmonic and fractal fluctuations have been described. Non-harmonic non-fractal fluctuation has not been studied because it is usually thought that it is caused by apparatus noise. We hypothesized that this fluctuation looking like apparatus noise (that we call "noisy fluctuation") is linked to challenged blood pressure stabilization and not to apparatus noise. We assessed noisy fluctuation by quantifying the small and fastest beat-to-beat fluctuation of RR-interval by means of spectral analysis (Nyquist power of heart rate variability: nyHRV) after filtering out its fractal component. We observed nyHRV in healthy supine subjects and in patients with vasovagal symptoms. We challenged stabilization of blood pressure by upright posture (by means of a head-up tilt table test). Head-up position on the tilt table dramatically decreased nyHRV (0.128 ± 0.063 vs. 0.004 ± 0.002, p cardiovascular system is challenged (upright posture). It also indicates cardiovascular instability because it does not disappear in upright patients before vasovagal syncope, a transient failure of cardiovascular regulation.
Artur Haddad Herdy
Full Text Available After many years away from the limelights, at the beginning of this century, exercise tolerance testing has earned back an important position in international medical journals. The different sorts of information derived from a variety of studies based on it have shown us that this propedeutic method has a highly valuable prognostic impact. Because of its low cost and easy applicability, the exercise testing reinforces its position in the clinical practice of the cardiologist. In the early 70's, research relating the influence of the autonomic nervous system in heart rate behavior in all phases of an exercise tolerance testing began. Ever since, a number of hypotheses tried to clarify which would be the mechanisms related to the chronotropic response during effort and its performance in the recovery period. In this updating article the authors deal with an important data referring to the chronotropic deficit and the abnormal heart rate recovery, commenting on the prognostic implication of keeping the focus on the potential of its clinical impact. In other words, approaches that can be used whenever there is someone performing a monitored exercise tolerance testing.
Salamon, Jaromír; Mouček, Roman
Sentiment extraction and analysis using spoken utterances or written corpora as well as collection and analysis of human heart rate data using sensors are commonly used techniques and methods. On the other hand, these have been not combined yet. The collected data can be used e.g. to investigate the mutual dependence of human physical and emotional activity. The paper describes the procedure of parallel acquisition of heart rate sensor data and tweets expressing sentiment and difficulties related to this procedure. The obtained datasets are described in detail and further discussed to provide as much information as possible for subsequent analyses and conclusions. Analyses and conclusions are not included in this paper. The presented experiment and provided datasets serve as the first basis for further studies where all four presented data sources can be used independently, combined in a reasonable way or used all together. For instance, when the data is used all together, performing studies comparing human sensor data, acquired noninvasively from the surface of the human body and considered as more objective, and human written data expressing the sentiment, which is at least partly cognitively interpreted and thus considered as more subjective, could be beneficial.
Ako, Mina; Kawara, Tokuhiro; Uchida, Sunao; Miyazaki, Shinichi; Nishihara, Kyoko; Mukai, Junko; Hirao, Kenzo; Ako, Junya; Okubo, Yoshiro
It is known that autonomic nervous activities change in correspondence with sleep stages. However, the characteristics of continuous fluctuations in nocturnal autonomic nerve tone have not been clarified in detail. The study aimed to determine the possible correlation between the electroencephalogram (EEG) and autonomic nervous activities, and to clarify in detail the nocturnal fluctuations in autonomic nerve activities. Overnight EEGs and electrocardiograms of seven healthy males were obtained. These EEGs were analyzed by fast Fourier transformation algorithm to extract delta, sigma and beta power. Heart rate and heart rate variability (HRV) were calculated in consecutive 5-min epochs. The HRV indices of low frequency (LF), high frequency (HF) and LF/HF ratio were calculated from the spectral analysis of R-R intervals. The sleep stages were manually scored according to Rechtschaffen and Kales' criteria. Low frequency and LF/HF were significantly lower during non-rapid eye movement (NREM) than REM, and were lower in stages 3 and 4 than in stages 1 and 2. Furthermore, delta EEG showed inverse correlations with LF (r = - 0.44, P lightening.
The purpose of this study is to make use of visible light reflected mode photoplethysmographic (PPG) imaging for heart rate (HR) monitoring via smartphones. The system uses the built-in camera feature in mobile phones to capture video from the subject's index fingertip. The video is processed, and then the PPG signal resulting from the video stream processing is used to calculate the subject's heart rate. Records from 19 subjects were used to evaluate the system's performance. The HR values obtained by the proposed method were compared with the actual HR. The obtained results show an accuracy of 99.7% and a maximum absolute error of 0.4 beats/min where most of the absolute errors lay in the range of 0.04-0.3 beats/min. Given the encouraging results, this type of HR measurement can be adopted with great benefit, especially in the conditions of personal use or home-based care. The proposed method represents an efficient portable solution for HR accurate detection and recording.
Aeschbacher, Stefanie; Bossard, Matthias; Ruperti Repilado, Francisco Javier; Good, Nathalie; Schoen, Tobias; Zimny, Matylda; Probst-Hensch, Nicole M; Schmidt-Trucksäss, Arno; Risch, Martin; Risch, Lorenz; Conen, David
We aimed to determine the association of a comprehensive healthy lifestyle with heart rate variability (HRV), a validated measure of autonomic function. This was a prospective cohort study. A population-based sample of 2079 individuals aged 25-41 years without prevalent cardiovascular disease was investigated. The standard deviation of all normal RR intervals (SDNN) during 24-hour electrocardiography was used as main HRV marker. Healthy lifestyle metrics were summed to a validated lifestyle-score ranging from 0 = most unhealthy to 7 = most healthy. One point was given for each of the following items: never smoking cigarettes; consuming a healthy diet; performing moderate (≥150 min/week) or vigorous (≥75 min/week) physical activity; body mass index (BMI)heart rate (HR) (β-estimate (95% CI) 0.07 (0.07-0.10), p healthy lifestyle in this large contemporary cohort of young adults from the general population. Adopting a healthy lifestyle has an important effect on autonomic function. © The European Society of Cardiology 2015.
Olufsen, Mette; Tran, Hien T.; Ottesen, Johnny T.
in healthy and hypertensive elderly people the hysteresis loop shifts to higher blood pressure values and its area is diminished. Finally, for hypertensive elderly people the hysteresis loop is generally not closed indicating that during postural change from sitting to standing, the blood pressure resettles....... The model uses blood pressure measured in the finger as an input to model heart rate dynamics in response to changes in baroreceptor nerve firing rate, sympathetic and parasympathetic responses, vestibulo-sympathetic reflex, and concentrations of norepinephrine and acetylcholine. We formulate an inverse...... validate our model against clinical data it is necessary to include the vestibulo-sympathetic reflex. Furthermore our model reveals that the transfer between the nerve firing and blood pressure is non-linear and follows a hysteresis curve. In healthy young people, the hysteresis loop is wide, while...
Miller, F C; Pearse, K E; Paul, R H
The thesis that obstetric health care personnel can discriminate characteristics of baseline fetal heart rate (FHR) and FHR patterns by auscultation needs to be tested. For this study, audiotones of the FHR signals were recorded for eight representative FHR patterns. Each recording was for three minutes and included one uterine contraction. Physicians and nurses who use continuous electronic FHR monitoring on a regular basis listened to the eight recordings and attempted to identify the baseline rate, variability, and periodic patterns, and then matched their perceptions with the eight corresponding FHR tracings (not in order). Baseline FHR and FHR without periodic patterns were most frequently identified correctly. Late decelerations with and without good baseline variability were misdiagnosed 18.4 and 33% of the time, respectively. Although the FHR characteristics and periodic patterns were correctly identified most of the time, failure to recognize significant periodic patterns by as many as one-third of the participants is unacceptable in modern obstetrics.
Amichai, Taly; Katz-Leurer, Michal
A systematic review which aims to assess the evidence regarding the function of the autonomic heart rate regulation system among children with cerebral palsy (CP). The target population included children with CP of diverse severity, aged 1.5 to 18 years. Databases searched for English language studies from 1960 to 2013: PubMed, EMBASE, CINAHL, Cochrane Library, The Physiotherapy Evidence Database (PEDro), and ClinicalTrials.gov site. Search terms included 'cerebral palsy' or 'spastic diplegia' or 'hemiplegia' or 'quadriplegia' and 'autonomic nervous system' or 'heart rate variability' or 'sympathetic' or 'para sympathetic'. Twenty five articles were identified and included if (1) participants were less than 18 years of age, (2) diagnosis of CP was made after the age of 18 months (3) more than 80% of cases had a diagnosis of CP and (4) autonomic cardiac heart rate regulation system state or response to a stimuli was described for all the participants. Six articles met the criteria for inclusion. Evidence suggests that reduced Heart Rate Variability (HRV) time domain parameters close to birth are associated with a CP diagnosis at the age of three years. In addition, HRV parameters' mean values, are significantly lower among children with CP compared to typically developed (TD) control. While performing head up, tilt or standing position, HRV was significantly reduced only among TD control, but no effect was seen in those variables among children with CP. Further studies are needed to assess the potential to predict CP by assessing HRV parameters among newborn children. In addition, assessing HRV among children with CP may improve our understanding of the heart rate autonomic system and its response to different stimulus such as muscle contraction, paced breathing and aerobic training.
Opdahl, Anders; Ambale Venkatesh, Bharath; Fernandes, Veronica R S; Wu, Colin O; Nasir, Khurram; Choi, Eui-Young; Almeida, Andre L C; Rosen, Boaz; Carvalho, Benilton; Edvardsen, Thor; Bluemke, David A; Lima, João A C
The objective of this study was to investigate the relationship between baseline resting heart rate and incidence of heart failure (HF) and global and regional left ventricular (LV) dysfunction. The association of resting heart rate to HF and LV function has not been well described in an asymptomatic multi-ethnic population. Resting heart rate was measured in participants in the MESA (Multi-Ethnic Study of Atherosclerosis) trial at inclusion. Incident HF was registered (n = 176) during follow-up (median 7 years) in those who underwent cardiac magnetic resonance imaging (n = 5,000). Changes in ejection fraction (ΔEF) and peak circumferential strain (Δεcc) were measured as markers of developing global and regional LV dysfunction in 1,056 participants imaged at baseline and 5 years later. Time to HF (Cox model) and Δεcc and ΔEF (multiple linear regression models) were adjusted for demographics, traditional cardiovascular risk factors, calcium score, LV end-diastolic volume, and mass in addition to resting heart rate. Cox analysis demonstrated that for 1 beat/min increase in resting heart rate, there was a 4% greater adjusted relative risk for incident HF (hazard ratio: 1.04; 95% CI: 1.02 to 1.06; p heart rate was positively associated with deteriorating εcc and decrease in EF, even when all coronary heart disease events were excluded from the model. Elevated resting heart rate was associated with increased risk for incident HF in asymptomatic participants in the MESA trial. Higher heart rate was related to development of regional and global LV dysfunction independent of subclinical atherosclerosis and coronary heart disease. (Multi-Ethnic Study of Atherosclerosis [MESA]; NCT00005487). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Chreiteh, Shadi; Belhage, Bo; Hoppe, Karsten
The heart rate variability (HRV) is a commonly used method to quantify the sympathetic and the parasympathetic modulation of the heart rate. HRV is mainly conducted on electrocardiograms (ECG). However, the use of photoplethysmography (PPG) as a marker of the autonomic tone is emerging....... In this study we investigated the feasibility of deriving pulse rate variability (PRV) using PPG signals recorded by a reflectance PPG sensor attached to the chest bone (sternum) and comparing it to HRV. The recordings were conducted on 9 healthy subjects being in a relaxed supine position and under forced...... the parameters (r > 0:95 with p using sternal PPG can be an alternative to HRV analysis on healthy subjects at rest....
Salvucci, Fernando Pablo; Schiavone, Jonathan; Craiem, Damian; Barra, Juan Gabriel
Vascular wall viscoelasticity can be evaluated using a first-order lumped model. This model consists of a spring with elastic constant E and a dashpot with viscous constant η. More importantly, this viscoelastic model can be fitted in-vivo measuring arterial pressure and diameter. The aim of this work is to analyze the influence of heart rate over E and η. In two anesthetized sheep, diameter in thoracic aorta and intravascular pressure has been registered. The right atrium was connected to a programmable stimulator through a pair of pace-maker wires to produce changes in stimulation heart rate (HR) from 80 to 160 bpm. Additionally, local activation of vascular smooth muscle was induced with phenylephrine. After converting pressure and diameter signals into stress and strain respectively, E y η were calculated in control state and during muscle activation. The elastic modulus E did not present significant changes with heart rate. The viscous modulus η decreased 49% with a two-fold acceleration in heart rate from 80 to 160 bpm. However, the product η HR remained stable. The viscous modulus η increased 39% with smooth muscle activation. No significant pressure changes were registered during the experiment. The contractile action of vascular smooth muscle could contribute to increasing arterial wall viscosity. The decrease of η when HR increased might be related to smooth muscle relaxation mediated by endothelium activity, which was stimulated by flow increase. We conclude that HR can modulate arterial wall viscoelasticity through endothelium-dependent mechanisms.
Weissman, A; Torkhov, O; Weissman, A I; Drugan, A
Epidural and parenteral opioid analgesia are two common methods of pain relief in labor that may influence the autonomic nervous system. However, these effects on laboring women have not yet been adequately studied. The aim of our study was to assess the effects of these two methods of analgesia on autonomic nervous system modulation of maternal heart rate variability in laboring women. A prospective observational study was conducted on 64 laboring women; 33 received epidural analgesia with bupivacaine and fentanyl and 31 intravenous meperidine and promethazine. Power spectral analysis and nonlinear methods were applied to digitized electrocardiograms performed before and after administration of analgesia, to assess maternal heart rate variability and autonomic equilibrium. Maternal heart rate significantly increased in women who received meperidine compared to those who had epidural analgesia. There was a significant increase in the low-frequency to high-frequency ratio (3.7+/-3.9 vs. 1.8+/-1.6, Ppower in women who had meperidine compared to those who received epidural analgesia (163+/-91 vs. 98+/-100 ms(2)/Hz, P<0.05). Meperidine caused an autonomic nervous system shift towards sympathetic activation with abolition of respiratory sinus arrhythmia high-frequency spectral band. Conversely epidural analgesia had no significant effect on autonomic nervous system control of heart rate.
Jones, Peter; Ovenden, Nick; Dauger, Stéphane; Peters, Mark J
Reductions in heart rate occur frequently in children during critical care intubation and are currently considered the gold standard for haemodynamic instability. Our objective was to estimate loss of heart beats during intubation and compare this to reduction in heart rate alone whilst testing the impact of atropine pre-medication. Data were extracted from a prospective 2-year cohort study of intubation ECGs from critically ill children in PICU/Paediatric Transport. A three step algorithm was established to exclude variation in pre-intubation heart rate (using a 95%CI limit derived from pre-intubation heart rate variation of the children included), measure the heart rate over time and fina