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Sample records for heart rate modulation

  1. Respiratory modulation and baroreflex control of heart rate in space

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    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

  2. Gum chewing modulates heart rate variability under noise stress.

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    Ekuni, Daisuke; Tomofuji, Takaaki; Takeuchi, Noriko; Morita, Manabu

    2012-12-01

    Gum chewing may relieve stress, although this hypothesis has not been proven. Heart-rate variability (HRV) is commonly used to measure stress levels. However, it is not known if gum chewing modulates HRV under acute stress. The aim of this study was to investigate the effects of gum chewing on HRV under acute stress. A cross-over study involving 47 non-smoking healthy subjects, aged 22-27 years, was carried out. The subjects received a stress procedure with gum chewing (GS group) and without gum chewing (S group). Additionally, the other 20 subjects were allocated to the gum chewing without stress group (G group). The GS and S groups were exposed to noise for 5 min (75 dBA) as stress. Before and after stress exposure/gum chewing, participants completed the state portion of the State-Trait Anxiety Inventory (STAI-s) and a single Stress Visual Analogue Scale (VAS) measurement. HRV measurement was performed before and during stress/gum chewing for 5 min. After the stress procedure, VAS score significantly increased in the GS and S groups. During the stress procedure, the GS group showed a significantly lower level of high frequency (HF) and higher levels of low frequency (LF) and LF/HF than the S group. However, there were no significant differences in the scores of the state portion of the State-Trait Anxiety Inventory (STAI-s) and VAS between the two stress groups. These findings suggest that gum chewing modulates HRV, but may not relieve acute stress caused by noise.

  3. The Influence of Motor Impairment on Autonomic Heart Rate Modulation among Children with Cerebral Palsy

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    Zamuner, Antonio Roberto; Cunha, Andrea Baraldi; da Silva, Ester; Negri, Ana Paola; Tudella, Eloisa; Moreno, Marlene Aparecida

    2011-01-01

    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…

  4. Modulations of Heart Rate, ECG, and Cardio-Respiratory Coupling Observed in Polysomnography

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    Thomas Penzel

    2016-10-01

    Full Text Available The cardiac component of cardio-respiratory polysomnography is covered by ECG and heart rate recordings. However their evaluation is often underrepresented in summarizing reports. As complements to EEG, EOG, and EMG, these signals provide diagnostic information for autonomic nervous activity during sleep. This review presents major methodological developments in sleep research regarding heart rate, ECG and cardio-respiratory couplings in a chronological (historical sequence. It presents physiological and pathophysiological insights related to sleep medicine obtained by new technical developments. Recorded nocturnal ECG facilitates conventional heart rate variability analysis, studies of cyclical variations of heart rate, and analysis of ECG waveform. In healthy adults, the autonomous nervous system is regulated in totally different ways during wakefulness, slow-wave sleep, and REM sleep. Analysis of beat-to-beat heart-rate variations with statistical methods enables us to estimate sleep stages based on the differences in autonomic nervous system regulation. Furthermore, up to some degree, it is possible to track transitions from wakefulness to sleep by analysis of heart-rate variations. ECG and heart rate analysis allow assessment of selected sleep disorders as well. Sleep disordered breathing can be detected reliably by studying cyclical variation of heart rate combined with respiration-modulated changes in ECG morphology (amplitude of R wave and T wave.

  5. Modulations of Heart Rate, ECG, and Cardio-Respiratory Coupling Observed in Polysomnography.

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    Penzel, Thomas; Kantelhardt, Jan W; Bartsch, Ronny P; Riedl, Maik; Kraemer, Jan F; Wessel, Niels; Garcia, Carmen; Glos, Martin; Fietze, Ingo; Schöbel, Christoph

    2016-01-01

    The cardiac component of cardio-respiratory polysomnography is covered by ECG and heart rate recordings. However, their evaluation is often underrepresented in summarizing reports. As complements to EEG, EOG, and EMG, these signals provide diagnostic information for autonomic nervous activity during sleep. This review presents major methodological developments in sleep research regarding heart rate, ECG, and cardio-respiratory couplings in a chronological (historical) sequence. It presents physiological and pathophysiological insights related to sleep medicine obtained by new technical developments. Recorded nocturnal ECG facilitates conventional heart rate variability (HRV) analysis, studies of cyclical variations of heart rate, and analysis of ECG waveform. In healthy adults, the autonomous nervous system is regulated in totally different ways during wakefulness, slow-wave sleep, and REM sleep. Analysis of beat-to-beat heart-rate variations with statistical methods enables us to estimate sleep stages based on the differences in autonomic nervous system regulation. Furthermore, up to some degree, it is possible to track transitions from wakefulness to sleep by analysis of heart-rate variations. ECG and heart rate analysis allow assessment of selected sleep disorders as well. Sleep disordered breathing can be detected reliably by studying cyclical variation of heart rate combined with respiration-modulated changes in ECG morphology (amplitude of R wave and T wave).

  6. Tonic activation of peripheral chemosensory function modulates vagal heart rate control in heart failure patients with paroxysmal atrialfibrillation

    NARCIS (Netherlands)

    Drexel, T.; Eickholt, C.; Muehlsteff, J.; Ritz, A.; Siekiera, M.; Kirmanoglou, K.; Shin, D.I.; Balzer, J.; Rassaf, T.; Kelm, M.; Meyer, C.

    2012-01-01

    Tonic activation of peripheral chemosensory function modulates vagalheart rate control in heart failure patients with paroxysmal atrialfibrillation Thomas Drexel1, Christian Eickholt1, Jens Mühlsteff2,Anita Ritz1, Markus Siekiera1, Kiriakos Kirmanoglou1, Dong-In Shin1,Jan Balzer1, Tienush Rassaf1,

  7. Endogenous Pain Modulation: Association with Resting Heart Rate Variability and Negative Affectivity.

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    Van Den Houte, Maaike; Van Oudenhove, Lukas; Bogaerts, Katleen; Van Diest, Ilse; Van den Bergh, Omer

    2017-07-21

    Several chronic pain syndromes are characterized by deficient endogenous pain modulation as well as elevated negative affectivity and reduced resting heart rate variability. In order to elucidate the relationships between these characteristics, we investigated whether negative affectivity and heart rate variability are associated with endogenous pain modulation in a healthy population. An offset analgesia paradigm with noxious thermal stimulation calibrated to the individual's pain threshold was used to measure endogenous pain modulation magnitude in 63 healthy individuals. Pain ratings during constant noxious heat stimulation to the arm (15 seconds) were compared with ratings during noxious stimulation comprising a 1 °C rise and return of temperature to the initial level (offset trials, 15 seconds). Offset analgesia was defined as the reduction in pain following the 1 °C decrease relative to pain at the same time point during continuous heat stimulation. Evidence for an offset analgesia effect could only be found when noxious stimulation intensity (and, hence, the individual's pain threshold) was intermediate (46 °C or 47 °C). Offset analgesia magnitude was also moderated by resting heart rate variability: a small but significant offset effect was found in participants with high but not low heart rate variability. Negative affectivity was not related to offset analgesia magnitude. These results indicate that resting heart rate variability (HRV) is related to endogenous pain modulation (EPM) in a healthy population. Future research should focus on clarifying the causal relationship between HRV and EPM and chronic pain by using longitudinal study designs. © 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  8. A single dose of dark chocolate increases parasympathetic modulation and heart rate variability in healthy subjects

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    Ana Amélia Machado DUARTE

    Full Text Available ABSTRACT Objective: The aim of this study was to investigate the acute effect of a single dose of dark chocolate (70% cocoa on blood pressure and heart rate variability. Methods: Thirty-one healthy subjects (aged 18-25 years; both sexes were divided into two groups: 10 subjects in the white chocolate (7.4 g group and 21 in the dark chocolate (10 g group; measurements were performed at the university's physiology lab. An electrocardiogram measured the sympathovagal balance by spectral and symbolic analysis. Results: A single dose of dark chocolate significantly reduced systolic blood pressure and heart rate. After consuming 10 g of dark chocolate, significant increases were observed for heart rate variability, standard deviation of RR intervals standard deviation of all NN intervals, square root of the mean squared differences between adjacent normal RR intervals root mean square of successive differences, and an increase in the high frequency component in absolute values, representing the parasympathetic modulation. Conclusion: In conclusion the importance of our results lies in the magnitude of the response provoked by a single dose of cocoa. Just 10 g of cocoa triggered a significant increase in parasympathetic modulation and heart rate variability. These combined effects can potentially increase life expectancy because a reduction in heart rate variability is associated with several cardiovascular diseases and higher mortality.

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

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    Federico eLombardi

    2011-12-01

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

  10. Inhalation/Exhalation ratio modulates the effect of slow breathing on heart rate variability and relaxation.

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    Van Diest, Ilse; Verstappen, Karen; Aubert, André E; Widjaja, Devy; Vansteenwegen, Debora; Vlemincx, Elke

    2014-12-01

    Slow breathing is widely applied to improve symptoms of hyperarousal, but it is unknown whether its beneficial effects relate to the reduction in respiration rate per se, or, to a lower inhalation/exhalation (i/e) ratio. The present study examined the effects of four ventilatory patterns on heart rate variability and self-reported dimensions of relaxation. Thirty participants were instructed to breathe at 6 or 12 breaths/min, and with an i/e ratio of 0.42 or 2.33. Participants reported increased relaxation, stress reduction, mindfulness and positive energy when breathing with the low compared to the high i/e ratio. A lower compared to a higher respiration rate was associated only with an increased score on positive energy. A low i/e ratio was also associated with more power in the high frequency component of heart rate variability, but only for the slow breathing pattern. Our results show that i/e ratio is an important modulator for the autonomic and subjective effects of instructed ventilatory patterns.

  11. Vagus Nerve Stimulation Modulates Complexity of Heart Rate Variability Differently during Sleep and Wakefulness.

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    Balasubramanian, Karthi; Harikumar, K; Nagaraj, Nithin; Pati, Sandipan

    2017-01-01

    Progressive loss of heart rate variability (HRV) and complexity are associated with increased risk of mortality in patients with cardiovascular disease and are a candidate marker for patients at risk of sudden cardiac death. HRV is influenced by the cardiac autonomic nervous system (ANS), although it is unclear which arm of the ANS (sympathetic or parasympathetic) needs to be perturbed to increase the complexity of HRV. In this case-control study, we have analyzed the relation between modulation of vagus nerve stimulation (VNS) and changes in complexity of HRV as a function of states of vigilance. We hypothesize that VNS - being a preferential activator of the parasympathetic system - will decrease the heart rate (HR) and increase the complexity of HRV maximum during sleep. The electrocardiogram (EKG) obtained from a 37-year-old, right-handed male with known intractable partial epilepsy and left therapeutic VNS was analyzed during wakefulness and sleep with VNS ON and OFF states. Age-matched control EKG was obtained from five participants (three with intractable epilepsy and two without epilepsy) that had no VNS implant. The study demonstrated the following: (1) VNS increased the complexity of HRV during sleep and decreased it during wakefulness. (2) An increase in parasympathetic tone is associated with increased complexity of HRV even in the presence of decreased HR. These results need to be replicated in a larger cohort before developing patterned stimulation using VNS to stabilize cardiac dysautonomia and prevent fatal arrhythmias.

  12. Vagus nerve stimulation modulates complexity of heart rate variability differently during sleep and wakefulness

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    Karthi Balasubramanian

    2017-01-01

    Full Text Available Progressive loss of heart rate variability (HRV and complexity are associated with increased risk of mortality in patients with cardiovascular disease and are a candidate marker for patients at risk of sudden cardiac death. HRV is influenced by the cardiac autonomic nervous system (ANS, although it is unclear which arm of the ANS (sympathetic or parasympathetic needs to be perturbed to increase the complexity of HRV. In this case–control study, we have analyzed the relation between modulation of vagus nerve stimulation (VNS and changes in complexity of HRV as a function of states of vigilance. We hypothesize that VNS – being a preferential activator of the parasympathetic system – will decrease the heart rate (HR and increase the complexity of HRV maximum during sleep. The electrocardiogram (EKG obtained from a 37-year-old, right-handed male with known intractable partial epilepsy and left therapeutic VNS was analyzed during wakefulness and sleep with VNS ON and OFF states. Age-matched control EKG was obtained from five participants (three with intractable epilepsy and two without epilepsy that had no VNS implant. The study demonstrated the following: (1 VNS increased the complexity of HRV during sleep and decreased it during wakefulness. (2 An increase in parasympathetic tone is associated with increased complexity of HRV even in the presence of decreased HR. These results need to be replicated in a larger cohort before developing patterned stimulation using VNS to stabilize cardiac dysautonomia and prevent fatal arrhythmias.

  13. Heart rate response and parasympathetic modulation during recovery from exercise in boys and men.

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    Guilkey, Justin P; Overstreet, Matthew; Fernhall, Bo; Mahon, Anthony D

    2014-08-01

    The purpose of this study was to examine the influence of postexercise parasympathetic modulation, measured by heart rate variability (HRV), on heart rate recovery (HRR) in boys (n = 13, 10.1 ± 0.8 years) and men (n = 13, 23.9 ± 1.5 years) following maximal and submaximal exercise. Subjects completed 10 min of supine rest, followed by graded exercise on a cycle ergometer to maximal effort. On a separate day, subjects exercised at an intensity equivalent to ventilatory threshold. Immediately following both exercise bouts, 1-min HRR was assessed in the supine position. HRV was analyzed under controlled breathing during the final 5 min of rest and recovery in the time and frequency domains and transformed to natural log (ln) values. Boys had a greater 1-min HRR than men following maximal (58 ± 8 vs. 47 ± 11 beats·min(-1)) and submaximal (59 ± 8 vs. 47 ± 15 beats·min(-1)) exercise (p boys had greater ln root mean square successive differences in R-R intervals (2.52 ± 0.95 ms), ln standard deviation of NN intervals (3.34 ± 0.57 ms), ln high-frequency power (4.32 ± 2.00 ms(2)), and ln low-frequency power (4.98 ± 1.17 ms(2)) than men (1.33 ± 0.37 ms, 2.52 ± 0.24 ms, 1.32 ± 1.06 ms(2) and 2.80 ± 0.74 ms(2), respectively) (p 0.05). In conclusion, it appears that greater parasympathetic modulation accounts for greater HRR following maximal exercise in boys versus men. Although submaximal HRR was greater in boys, parasympathetic responses were similar between groups.

  14. Origin of Heart Rate Variability and Turbulence: An Appraisal of Autonomic Modulation of Cardiovascular Function

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    Lombardi, Federico; Stein, Phyllis K.

    2011-01-01

    Heart period constantly changes on a beat to beat basis, due to autonomic influences on the sinoatrial node, and changes can be quantified as heart rate variability (HRV). In addition, after a premature ventricular beat, there are reproducible variations in RR interval, also due to baroreflex mediated autonomic influences on the sinoatrial node, that can be measured as heart rate turbulence (HRT). Impaired autonomic function as measured by HRV and HRT has proven to predict adverse outcomes in clinical settings. The ability of reduced HRV and HRT to predict adverse outcomes has been explained by their dependency on vagal mechanisms that could reflect an increased sympathetic and a reduced vagal modulation of sinus node, thus favoring cardiac electrical instability. Analysis of non-linear dynamics of HRV has also been utilized to describe the fractal like characteristic of the variability signal and proven effective in identify patients at risk for sudden cardiac death. Despite the clinical validity of these measures, it has also been evident that the relationship between neural input and sinus node responsiveness is extremely complex and variable in different clinical conditions. Thus, abnormal HRV or HRT on a clinical Holter recordings may reflect non-neural as well as autonomic mechanisms, and this also needs to be taken into account when interpreting any findings. However, under controlled conditions, the computation of the low and high frequency components of HRV and of their normalized powers or ratio seems capable of providing valid information on sympatho-vagal balance in normal subjects, as well as in most patients with a preserved left ventricular function. Thus, analysis of HRV does provide a unique tool to specifically assess autonomic control mechanisms in association with various perturbations. In conclusion, HRV measures are of substantial utility to identify patients with an increased cardiac mortality and to evaluate autonomic control mechanisms, but

  15. Heart rate modulation in stable coronary artery disease without clinical heart failure: What we have already learned from SIGNIFY?

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    Gian Piero Perna

    2016-12-01

    In conclusion, heart rate is a marker of risk but is not a risk factor and/or a target of therapy in patients with stable coronary artery disease and preserved ventricular systolic function. Standard doses of ivabradine are indicated for treatment of angina as an alternative or in addition to beta-blockers, but should not be administered in association with CYP3A4 inhibitors or heart rate-lowering calcium-channel blockers.

  16. Loss of Breathing Modulation of Heart Rate Variability in Patients with Recent and Long Standing Diabetes Mellitus Type II.

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    Rivera, Ana Leonor; Estañol, Bruno; Fossion, Ruben; Toledo-Roy, Juan C; Callejas-Rojas, José A; Gien-López, José A; Delgado-García, Guillermo R; Frank, Alejandro

    2016-01-01

    Healthy subjects under rhythmic breathing have heart interbeat intervals with a respiratory band in the frequency domain that can be an index of vagal activity. Diabetes Mellitus Type II (DM) affects the autonomic nervous system of patients, thus it can be expected changes on the vagal activity. Here, the influence of DM on the breathing modulation of the heart rate is evaluated by analyzing in the frequency domain heart interbeat interval (IBI) records obtained from 30 recently diagnosed, 15 long standing DM patients, and 30 control subjects during standardized clinical tests of controlled breathing at 0.1 Hz, supine rest and standing upright. Fourier spectral analysis of IBI records quantifies heart rate variability in different regions: low-frequencies (LF, 0.04-0.15 Hz), high-frequencies (HF, 0.15-0.4 Hz), and a controlled breathing peak (RP, centered around 0.1 Hz). Two new parameters are introduced: the frequency radius rf (square root of the sum of LF and HF squared) and β (power of RP divided by the sum of LF and HF). As diabetes evolves, the controlled breathing peak loses power and shifts to smaller frequencies, indicating that heart rate modulation is slower in diabetic patients than in controls. In contrast to the traditional parameters LF, HF and LF/HF, which do not show significant differences between the three populations in neither of the clinical tests, the new parameters rf and β, distinguish between control and diabetic subjects in the case of controlled breathing. Sympathetic activity that is driven by the baroreceptor reflex associated with the 0.1 Hz breathing modulations is affected in DM patients. Diabetes produces not only a rigid heartbeat with less autonomic induced variability (rf diminishes), but also alters the coupling between breathing and heart rate (reduced β), due to a progressive decline of vagal and sympathetic activity.

  17. Associations of Heart Rate With Inflammatory Markers Are Modulated by Gender and Obesity in Older Adults.

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    Laudisio, Alice; Bandinelli, Stefania; Gemma, Antonella; Ferrucci, Luigi; Incalzi, Raffaele Antonelli

    2015-07-01

    Faster resting heart rate (HR), which is associated with inflammation and elevated cortisol levels, is a risk factor for excess cardiovascular morbidity and mortality. Obesity is associated with increased cardiovascular morbidity and mortality, inflammation, and elevated cortisol levels. The aim of the present study was to evaluate the interaction of Body Mass Index (BMI) with inflammation and cortisol in modulating HR in older subjects. We analyzed data of 895 participants aged 65+ enrolled in the "InCHIANTI" study, in sinus rhythm, and not taking beta blockers or digoxin. Linear regression was performed to assess the adjusted association between HR, IL-6, and cortisol levels. The model was also analyzed stratifying for BMI tertiles. Logistic regression was adopted for evaluating the association of HR exceeding the mean value with Il-6 and serum cortisol. According to multivariable linear regression, IL-6 and cortisol levels were associated with HR (B = 1.42, 95% CI = 0.43-2.42; p = .005 and B = .34, 95% CI = 0.17-.51; p cortisol). Logistic regression confirmed that IL-6 and cortisol levels were associated with HR above the mean value in the highest BMI tertile (OR = 2.13, 95% CI = 1.15-3.97; p = .009 and OR = 1.14, 95% CI = 1.03-1.25; p = .009, respectively). Faster HR is associated with proinflammatory state in elderly patients; this association seems to be limited to women with higher BMI. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Analysis of autonomic modulation of heart rate in patients with Parkinson's disease and elderly individuals submitted to game therapy training.

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    Rocha, Rodrigo Santiago Barbosa; De Oliveira Rocha, Larissa Salgado; Pena, Elza Sara Maués; Caldas, Laiz Cristinna Ponce; Moreno, Marlene Aparecida

    2018-01-01

    Elderly patients and individuals with Parkinson's disease have a reduction in autonomic heart rate modulation, which may influence the survival of these patients, and rehabilitation can minimize this event. We tested the hypothesis that rehabilitation protocol with game console would influence the cardiac autonomic modulation of patients with Parkinson's Disease. Eight-seven volunteers were divided into two groups, control (n = 45) and Parkinson's (n = 42), they completed the study 40 volunteers in the control group (CG) and 31 patients in the Parkinson group (PG), and subjected to 24 sessions of game therapy physiotherapy, thrice a week. Analysis of autonomic HR modulation was conducted before and after the rehabilitation program using a Polar RS800CX HR sensor. For the analysis of heart rate variability the data were transferred to the Kubios HRV 2.2 program. Statistical analysis was performed in the Biostat 5.2 program, the comparison of the data by ANOVA followed by Tukey test, and the general characteristics by the chi-square test. The critical value for rejecting the null hypothesis was set at P modulation of HR values. Subjects with PD exhibit less autonomic modulation of HR and the rehabilitation protocol with game therapy improved autonomic modulation of HR. Geriatr Gerontol Int 2018; 18: 20-25. © 2017 Japan Geriatrics Society.

  19. Heart rate index

    DEFF Research Database (Denmark)

    Haedersdal, C; Pedersen, F H; Svendsen, J H

    1992-01-01

    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...

  20. Effect of acute nitric oxide synthase inhibition in the modulation of heart rate in rats

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    A.L. Fellet

    2003-05-01

    Full Text Available Acute nitric oxide synthase inhibition with N G-nitro-L-arginine methyl ester (L-NAME on chronotropic and pressor responses was studied in anesthetized intact rats and rats submitted to partial and complete autonomic blockade. Blood pressure and heart rate were monitored intra-arterially. Intravenous L-NAME injection (7.5 mg/kg elicited the same hypertensive response in intact rats and in rats with partial (ganglionic and parasympathetic blockade and complete autonomic blockade (38 ± 3, 55 ± 6, 54 ± 5, 45 ± 5 mmHg, respectively; N = 9, P = NS. L-NAME-induced bradycardia at the time when blood pressure reached the peak plateau was similar in intact rats and in rats with partial autonomic blockade (43 ± 8, 38 ± 5, 46 ± 6 bpm, respectively; N = 9, P = NS. Rats with combined autonomic blockade showed a tachycardic response to L-NAME (10 ± 3 bpm, P<0.05 vs intact animals, N = 9. Increasing doses of L-NAME (5.0, 7.5 and 10 mg/kg, N = 9 caused a similar increase in blood pressure (45 ± 5, 38 ± 3, 44 ± 9 mmHg, respectively; P = NS and heart rate (31 ± 4, 34 ± 3, 35 ± 4 bpm, respectively; P = NS. Addition of L-NAME (500 µM to isolated atria from rats killed by cervical dislocation and rats previously subjected to complete autonomic blockade did not affect spontaneous beating or contractile strength (N = 9. In vivo results showed that L-NAME promoted a tachycardic response in rats with complete autonomic blockade, whereas the in vitro experiments showed no effect on intrinsic heart rate, suggesting that humoral mechanisms may be involved in the L-NAME-induced cardiac response.

  1. Modeling Tolerance Development for the Effect on Heart Rate of the Selective S1P1 Receptor Modulator Ponesimod.

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    Lott, Dominik; Lehr, Thorsten; Dingemanse, Jasper; Krause, Andreas

    2017-09-15

    Ponesimod is a selective sphingosine-1-phosphate-1 (S1P 1 ) receptor modulator currently under investigation for the treatment of multiple sclerosis. S1P receptor modulators reduce heart rate following treatment initiation. This effect disappears with repeated dosing, enabling development of innovative uptitration regimens to optimize patient safety. There are currently no published pharmacokinetic/pharmacodynamic models describing the heart rate reduction of S1P receptor modulators in humans. The model developed here provides quantification of this effect for ponesimod. A direct-effect I max model with estimated maximum reduction of 45%, tolerance development, and circadian variation best described this effect. The pooled data from nine clinical studies enabled characterization of interindividual variability. The model was used to simulate different treatment regimens to compare the effect of high initial doses vs. gradual uptitration with respect to the occurrence of bradycardia. The results indicate a better safety profile when using gradual uptitration. The model allows studying dosing regimens not clinically tested in silico. © 2017 American Society for Clinical Pharmacology and Therapeutics.

  2. Utility of a novel biofeedback device for within-breath modulation of heart rate in rats: a quantitative comparison of vagus nerve versus right atrial pacing.

    Directory of Open Access Journals (Sweden)

    Erin Louise O'Callaghan

    2016-02-01

    Full Text Available In an emerging bioelectronics era, there is a clinical need for physiological devices incorporating biofeedback that permits natural and demand-dependent control in real time. Here, we describe a novel device termed a central pattern generator (CPG that uses cutting edge analogue circuitry producing temporally controlled, electrical stimulus outputs based on the real time integration of physiological feedback. Motivated by the fact that respiratory sinus arrhythmia (RSA, which is the cyclical changes in heart rate every breath, is an essential component of heart rate variability (an indicator of cardiac health, we have explored the versatility and efficiency of the CPG for producing respiratory modulation of heart rate in anaesthetised, spontaneously breathing rats. Diaphragmatic electromyographic activity was used as the input to the device and its output connected to either the right cervical vagus nerve or the right atrium for pacing heart rate. We found that the CPG could induce respiratory related heart rate modulation that closely mimicked RSA. Whether connected to the vagus nerve or right atrium, the versatility of the device was demonstrated by permitting: (i heart rate modulation in any phase of the respiratory cycle, (ii control of the magnitude of heart rate modulation and (iii instant adaptation to changes in respiratory frequency. Vagal nerve pacing was only possible following transection of the nerve limiting its effective use chronically. Pacing via the right atrium permitted better flexibility and control of heart rate above its intrinsic level. This investigation now lays the foundation for future studies using this biofeedback technology permitting closer analysis of both the function and dysfunction of RSA.

  3. Preterm birth has sex-specific effects on autonomic modulation of heart rate variability in adult sheep.

    Directory of Open Access Journals (Sweden)

    Mary Berry

    Full Text Available INTRODUCTION: Globally, 11% of infants are born preterm. In adulthood, individuals born preterm are at increased risk of cardiovascular morbidity and mortality, but the mechanistic basis of this remains unknown. Clinically overt cardiovascular disease may be preceded by altered cardiac autonomic activity characterised by increased sympathetic activity and/or reduced parasympathetic activity. Thus, altered cardiac autonomic activity in survivors of preterm birth may underlie later cardiovascular risk. OBJECTIVE: To investigate the impact of gestational age on cardiac autonomic activity in juvenile and adult sheep. METHODS AND RESULTS: Singleton-bearing ewes were randomised antenatally to spontaneous term birth (TC; n=73 or corticosteroid induced preterm birth (PT; n=60. Cardiac autonomic modulation was assessed using heart rate variability analysis in juvenile and adult offspring. Preterm birth in adult males was associated with altered sympatho-vagal modulation (LFnu: PT 64 ± 4 vs. TC 49 ± 4, p<0.05; LogLF/HF: PT 1.8 ± 0.1 vs. TC 1.5 ± 0.1, p<0.05 and reduced parasympathetic modulation (LogRMSSD: PT 2.9 ± 0.2 vs. TC 3.4 ± 0.1, p<0.05; LogNN50: PT 0.3 ± 0.4 vs. TC 1.6 ± 0.4, p<0.05. Within the range of term birth, each one-day increment in gestational age was associated with a decrement in LFnu in juvenile females and with a decrement in LFnu and LF/HF ratio, but an increment in RMSSD and NN50 in adult females. CONCLUSIONS: Cardiac autonomic function in adult sheep is affected in a sex-specific manner by gestational age at birth, even within the term range. Altered cardiac autonomic function may contribute to increased later cardiovascular morbidity in those born preterm.

  4. Modeling of Diffusion Based Correlations Between Heart Rate Modulations and Respiration Pattern

    National Research Council Canada - National Science Library

    Langer, R

    2001-01-01

    ...? ̂ What is the tradeoff between maintaining a constant blood flow rate through the pulmonary system, and, maintaining a constant oxygen saturation level of the blood flowing through the pulmonary system...

  5. Investigation of influence of 16-slice spiral CT electrocardiogram-controlled dose modulation on exposure dosage and image quality of cardiac CT imaging under simulated fluctuant heart rate

    International Nuclear Information System (INIS)

    Yin Yan; Chen Jie; Chai Weiming; Hua Jia; Gao Na; Xu Jianrong; Shen Yun

    2008-01-01

    Objective: To investigate the influence of electrocardiogram (ECG)-controlled dose modulation on exposure dosage and image quality of cardiac CT imaging in a cardiac phantom with simulated fluctuant heart rate. Methods: The basal heart rate of the cardiac pulsating phantom was set as 60 bpm, the experimental situations were divided as 6 groups according to different heart rates. The cardiac imaging was performed on the cardiac phantom when the ECG-controlled dose modulation was firstly turned off. The exposure dosage of each scan sequence was documented. The standard deviation of the CT values of the phantom was measured on the central slice after coronal reformation of the raw data. The quality of 2D and 3D images were scored. Then cardiac imaging was performed when ECG modulation was on and set as four groups according to different modulation parameters. All the data were documented as before. The results from the five groups with and without ECG modulation current were analyzed by F test and comparative rank sum test using the statistical software SPSS 10.0. Results: Statistical analysis showed no significant difference (P>0.05) between the SNR of images (SD value was 27.78 and 26.30) from the groups that full mA output at wide reconstruction phase (69%-99%) when the heart rate was fluctuant(≥7.5 bpm). There was also no significant difference (P>0.05) between the quality of the 2D and 3D images. But there was a significant difference (P 12.5 bpm, the exposure dosage would increase obviously (from 0.6 to 1.7 mSv). Conclusion: For cardiac imaging with 16-slice row CT, the application of ECG modulated current can effectively reduce the exposure dosage without compromising the image quality even if heart rate was fluctuant. (authors)

  6. Modulation of heart rate response to acute stressors throughout the breeding season in the king penguin Aptenodytes patagonicus.

    Science.gov (United States)

    Viblanc, Vincent A; Smith, Andrew D; Gineste, Benoit; Kauffmann, Marion; Groscolas, René

    2015-06-01

    'Fight-or-flight' stress responses allow animals to cope adaptively to sudden threats by mobilizing energy resources and priming the body for action. Because such responses can be costly and redirect behavior and energy from reproduction to survival, they are likely to be shaped by specific life-history stages, depending on the available energy resources and the commitment to reproduction. Here, we consider how heart rate (HR) responses to acute stressors are affected by the advancing breeding season in a colonial seabird, the king penguin (Aptenodytes patagonicus). We subjected 77 birds (44 males, 33 females) at various stages of incubation and chick-rearing to three experimental stressors (metal sound, distant approach and capture) known to vary both in their intensity and associated risk, and monitored their HR responses. Our results show that HR increase in response to acute stressors was progressively attenuated with the stage of breeding from incubation to chick-rearing. Stress responses did not vary according to nutritional status or seasonal timing (whether breeding was initiated early or late in the season), but were markedly lower during chick-rearing than during incubation. This pattern was obvious for all three stressors. We discuss how 'fight-or-flight' responses may be modulated by considering the energy commitment to breeding, nutritional status and reproductive value of the brood in breeding seabirds. © 2015. Published by The Company of Biologists Ltd.

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

    Directory of Open Access Journals (Sweden)

    Maaike Van Den Houte

    2018-03-01

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

  8. Cardiac Autonomic Modulation and the Kinetics of Heart Rate Responses in the On- and Off-Transient during Exercise in Women with Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Lucas R. B. E. Silva

    2017-07-01

    Full Text Available Objective: To test whether women with metabolic syndrome (MS have impairments in the on- and off-transients during an incremental test and to study whether any of the MS components are independently associated with the observed responses.Research Design and Methods: Thirty-six women aged 35–55 years were divided into a group with MS (MSG, n = 19 and a control group (CG, n = 17. R-R intervals (RRi and heart rate variability (HRV were calculated on a beat-to-beat basis and the heart rate (HR at the on- and off-transient were analyzed during an incremental cardiopulmonary exercise test (CPET.Results: MSG showed lower aerobic capacity and lower parasympathetic cardiac modulation at rest compared with CG. HR values in on-transient phase were significantly lower in MSG compared with CG. The exponential amplitudes “amp” and the parameters “τ” [speed of heart rate recovery (HRR] were lower in MSG. MSG exhibited higher HR values in comparison to CG during the off-transient indicating a slower HRR. In MSG, there was an inverse and significant correlation between fasting plasma vs. ΔF and glucose vs. exponential “τ” of HRR dynamics.Conclusion: MS is associated with poor heart rate kinetics. The altered HR kinetics seems to be related to alterations in cardiac parasympathetic modulation, and glucose metabolism seems to be the major determinant.

  9. Cardiac Autonomic Modulation and the Kinetics of Heart Rate Responses in the On- and Off-Transient during Exercise in Women with Metabolic Syndrome

    Science.gov (United States)

    Silva, Lucas R. B. E.; Zamunér, Antonio R.; Gentil, Paulo; Alves, Fagner M.; Leal, Acácia G. F.; Soares, Viviane; Silva, Maria S.; Vieira, Marcus F.; Simões, Karina; Pedrino, Gustavo R.; Rebelo, Ana C. S.

    2017-01-01

    Objective: To test whether women with metabolic syndrome (MS) have impairments in the on- and off-transients during an incremental test and to study whether any of the MS components are independently associated with the observed responses. Research Design and Methods: Thirty-six women aged 35–55 years were divided into a group with MS (MSG, n = 19) and a control group (CG, n = 17). R-R intervals (RRi) and heart rate variability (HRV) were calculated on a beat-to-beat basis and the heart rate (HR) at the on- and off-transient were analyzed during an incremental cardiopulmonary exercise test (CPET). Results: MSG showed lower aerobic capacity and lower parasympathetic cardiac modulation at rest compared with CG. HR values in on-transient phase were significantly lower in MSG compared with CG. The exponential amplitudes “amp” and the parameters “τ” [speed of heart rate recovery (HRR)] were lower in MSG. MSG exhibited higher HR values in comparison to CG during the off-transient indicating a slower HRR. In MSG, there was an inverse and significant correlation between fasting plasma vs. ΔF and glucose vs. exponential “τ” of HRR dynamics. Conclusion: MS is associated with poor heart rate kinetics. The altered HR kinetics seems to be related to alterations in cardiac parasympathetic modulation, and glucose metabolism seems to be the major determinant. PMID:28798697

  10. Target Heart Rates

    Science.gov (United States)

    ... Check Recipe Certification Program Nutrition Requirements Heart-Check Professional Resources Contact the Heart-Check Certification Program Simple Cooking and Recipes Dining Out Choosing a Restaurant Deciphering ...

  11. Effects of Liraglutide on Heart Rate and Heart Rate Variability

    DEFF Research Database (Denmark)

    Kumarathurai, Preman; Anholm, Christian; Larsen, Bjørn Strøier

    2017-01-01

    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...

  12. Heart rate response to breathing

    DEFF Research Database (Denmark)

    Mehlsen, J; Pagh, K; Nielsen, J S

    1987-01-01

    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...

  13. The 5-HTTLPR genotype modulates heart rate variability and its adjustment by pharmacological panic challenge in healthy men.

    Science.gov (United States)

    Agorastos, Agorastos; Kellner, Michael; Stiedl, Oliver; Muhtz, Christoph; Becktepe, Jos S; Wiedemann, Klaus; Demiralay, Cüneyt

    2014-03-01

    Abnormal serotonin transporter (5-HTT) function and autonomic nervous system (ANS) dysregulation has been proposed in panic disorder. However, in contrast to hypothalamo-pituitary-adrenocortical (HPA) functioning, ANS reactivity during panic response has yet not been investigated in humans with respect to the 5-HTT genotype. The present study assessed the influence of challenging by cholecystokinin tetrapeptide (CCK-4) on heart rate variability (HRV) measures, to monitor autonomic reactivity and its relationship to 5-HTT-linked polymorphic region (5-HTTLPR) genotypes. We hypothesized substantial effects of the 5-HTTLPR genotype on autonomic reactivity. We studied 30 healthy young men, 15 of each with the long/long (l/l) or short/short (s/s) genotype for the 5-HTTLPR. All participants received an intravenous application of 50 μg CCK-4. HRV measures were assessed in both groups at baseline and immediately after CCK-4 application. Our results indicated lower parasympathetic activity in s/s carriers during baseline, time and frequency domain measures. CCK-4 application significantly enhanced the sympathetic tone in both groups, leading to diminished group differences. A significant treatment by genotype effect indicated reduced autonomic reactivity to CCK-4 challenge in the s/s compared to l/l carriers. Our findings show enhanced sympathetic and/or diminished cardiac vagal activity under basal conditions and blunted autonomic reactivity in s/s vs. l/l carriers. Our study provides novel data supporting claims that the s/s genotype represents a genetic vulnerability factor associated with inadequate hyporeactivity to stress and extends current knowledge on the impact of the central serotonergic activity on the sympathoadrenal pathway. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Blood Pressure vs. Heart Rate

    Science.gov (United States)

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Blood Pressure vs. Heart Rate (Pulse) Updated:Nov 13,2017 ... This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP Introduction What ...

  15. Heart rate and heart rate variability in dogs with different degrees of myxomatous mitral valve disease

    DEFF Research Database (Denmark)

    Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth

    2011-01-01

    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 Copenhagen, Frederiksberg, Denmark. 2. Novo Nordic A/S, Maaloev, Denmark. 3. Department of Clinical Sciences, Swedish University of Agricultural Science, Uppsala, Sweden. Heart rate variability (HRV) is an indirect measurement of the autonomic modulation of heart rate (HR). Reduced HRV measured from short......-time electrocardiography is seen in dogs with heart failure (HF) secondary to myxomatous mitral valve disease (MMVD). However, HRV is suggested to increase with disease severity at early stages of MMVD. The aims of this study were 1) to associate HR and HRV with severity of MMVD in Cavalier King Charles Spaniels (CKCS...

  16. Fetal Heart Rate Monitoring during Labor

    Science.gov (United States)

    f AQ FREQUENTLY ASKED QUESTIONS FAQ015 LABOR, DELIVERY, AND POSTPARTUM CARE Fetal Heart Rate Monitoring During Labor • What is fetal heart rate monitoring? • Why is fetal heart rate monitoring ...

  17. Potassium supplementation and heart rate

    NARCIS (Netherlands)

    Gijsbers, L.; Molenberg, Famke; Bakker, S.J.L.; Geleijnse, J.M.

    2016-01-01

    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

  18. Heart rate, heart rate variability, and arrhythmias in dogs with myxomatous mitral valve disease

    DEFF Research Database (Denmark)

    Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth

    2012-01-01

    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)....

  19. [Resting heart rate and cardiovascular disease].

    Science.gov (United States)

    Brito Díaz, Buenaventura; Alemán Sánchez, José Juan; Cabrera de León, Antonio

    2014-07-07

    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.

  20. Heart rate in professional musicians

    Directory of Open Access Journals (Sweden)

    García Daniel

    2008-07-01

    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.

  1. Reduced Dietary Sodium Intake Increases Heart Rate

    DEFF Research Database (Denmark)

    Graudal, Niels A; Hubeck-Graudal, Thorbjørn; Jürgens, Gesche

    2016-01-01

    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 sodium reduction...

  2. Scale Invariant Properties in Heart Rate Signals

    Science.gov (United States)

    Makowiec, D.; Dudkowska, A.; Zwierz, M.; Galaska, R.; Rynkiewicz, A.

    2006-05-01

    The rate of heart beat is controlled by autonomic nervous system: accelerated by the sympathetic system and slowed by the parasympathetic system. Scaling properties in heart rate are usually related to the intrinsic dynamics of this physiological regulatory system. The two packages calculating local exponent spectra: Wavelet Transform Modulus Maxima and Multifractal Detrended Fluctuation Analysis (accessible from Physionet home page http://circ.ahajournals.org/cgi/content/full/101/23/e215) are tested, and then used to investigate the spectrum of singularity exponents in series of heart rates obtained from patients suffering from reduced left ventricle systolic function. It occurs that this state of a heart could be connected to some perturbation in the regulatory system, because the heart rate appears to be less controlled than in a healthy human heart. The multifractality in the heart rate signal is weakened: the spectrum is narrower and moved to higher values what indicate the higher activity of the sympatethic nervous system.

  3. Resting heart rate, heart rate variability and functional decline in old age

    DEFF Research Database (Denmark)

    Ogliari, Giulia; Mahinrad, Simin; Stott, David J

    2015-01-01

    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...

  4. Factors Influencing Heart Rate Variability

    Directory of Open Access Journals (Sweden)

    Stefan Sammito

    2016-01-01

    Full Text Available The measurement and analysis of heart rate variability (HRV, which is based on the variation between consecutive NN intervals, has become an established procedure over the past two decades. A decrease in HRV has been shown to correlate with an increase in mortality. HRV is influenced by a number of physiological factors such as various diseases. Awareness of these mediators or confounders is of great importance in the analysis and assessment of HRV both in scientific studies and in clinical practice. This document, which is based on a selective survey of references and supplemented by information from national and international guidelines, presents the main endogenous, exogenous and constitutional factors. A decrease in HRV has been observed not only in connection with non-influenceable physiological factors such as age, gender and ethnic origin, but also in conjunction with a large number of acute and chronic diseases. Numerous lifestyle factors have both a positive and a negative influence on HRV. There are also physical influences that affect HRV. They must on no account be disregarded. Although the list of the factors is long and not all of them have yet been fully studied, awareness of them is of crucial importance in the measurement of HRV (both under laboratory conditions and during medical practice, its analysis and its assessment. More research also needs to be carried out to close knowledge gaps.

  5. Maternal heart rate changes during labour.

    Science.gov (United States)

    Söhnchen, N; Melzer, K; Tejada, B Martinez de; Jastrow-Meyer, N; Othenin-Girard, V; Irion, O; Boulvain, M; Kayser, B

    2011-10-01

    Labour and delivery represent a considerable effort for pregnant women. Lack of aerobic fitness may limit pushing efforts during childbirth and represents increased cardiovascular strain and risk. Increasing prevalence of sedentary behaviour and lack of aerobic fitness may reduce heart rate reserve during labour. We quantified maternal heart rate reserve (maximum heart rate minus resting heart rate) of 30 healthy pregnant women during labour and delivery and related it to habitual daily physical activity levels quantified during the third pregnancy trimester by the Pregnancy Physical Activity Questionnaire. Heart rates during labour reached values similar to those observed during moderate to heavy physical exercise. During active pushing one out of five women reached heart rates more than 90% of their heart rate reserve (188 ± 7 beats per min). Half of the women reached more than 70% of heart rate reserve (172 ± 14 beats per min). Physically inactive women used more of their heart rate reserve as physically more active women (87 ± 20% vs. 65 ± 12%, upper and lower tertile respectively, plabour is increased in physically inactive women and may potentially limit the intensity and duration of pushing efforts. Such higher cardiovascular strain in physically less active women may represent increased cardiovascular risk during labour. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  6. Mental load, heart rate and heart rate variability.

    NARCIS (Netherlands)

    Blitz, P.S.; Hoogstraten, J.; Mulder, G.

    1970-01-01

    "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

  7. Measuring heart rate with optical sensor

    NARCIS (Netherlands)

    Barachi, M. (Mitra)

    2014-01-01

    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

  8. [Resonance hypothesis of heart rate variability origin].

    Science.gov (United States)

    Sheĭkh-Zade, Iu R; Mukhambetaliev, G Kh; Cherednik, I L

    2009-09-01

    A hypothesis is advanced of the heart rate variability being subjected to beat-to-beat regulation of cardiac cycle duration in order to ensure the resonance interaction between respiratory and own fluctuation of the arterial system volume for minimization of power expenses of cardiorespiratory system. Myogenic, parasympathetic and sympathetic machanisms of heart rate variability are described.

  9. Heart rate variability in patients undergoing univentricular heart repair.

    Science.gov (United States)

    Madan, Kushal; Garg, Pankaj; Deepak, Kishore Kumar; Talwar, Sachin; Airan, Balram; Choudhary, Shiv Kumar

    2014-05-01

    Altered cardiac autonomic control may play a role in the long-term outcome of patients undergoing univentricular heart repair. This study was undertaken to compare bidirectional superior cavopulmonary anastomosis with preserved antegrade pulmonary blood flow and total cavopulmonary connection, with regard to their effects on cardiac autonomic activity, as measured by heart rate variability indices, prior to and early after surgery. This prospective study included 46 patients (27 with bidirectional superior cavopulmonary anastomosis and 19 with total cavopulmonary connection. Heart rate variability was measured preoperatively and at 2 and 9 months postoperatively. The heart rate variability was measured by a 900-s electrocardiogram recording. Comparisons were drawn between and within groups, using standard statistical methods. All heart rate variability parameters were comparable in the 2 groups preoperatively. At the first follow-up, all heart rate variability parameters had decreased in both groups, but the decreases were not statistically significant. Between-group comparisons showed significantly higher parasympathetic and lower sympathetic tone in the bidirectional superior cavopulmonary anastomosis group. At the second follow-up, the bidirectional superior cavopulmonary anastomosis group had a significant increase in overall cardiac autonomic tone, and the total cavopulmonary connection group had a significant increase in parasympathetic tone, compared to the first follow-up. Between-group comparisons showed higher cardiac autonomic tone in the bidirectional superior cavopulmonary anastomosis group. Total cavopulmonary connection leads to a significant reduction in overall cardiac autonomic tone, compared to bidirectional superior cavopulmonary anastomosis with antegrade pulmonary blood flow.

  10. Heart rate and respiratory rate influence on heart rate variability repeatability: effects of the correction for the prevailing heart rate

    Directory of Open Access Journals (Sweden)

    Jakub Sławomir Gąsior

    2016-08-01

    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.

  11. Heart rate variability in healthy population

    International Nuclear Information System (INIS)

    Alamgir, M.; Hussain, M.M.

    2010-01-01

    Background: Heart rate variability has been considered as an indicator of autonomic status. Little work has been done on heart rate variability in normal healthy volunteers. We aimed at evolving the reference values of heart rate variability in our healthy population. Methods: Twenty-four hour holter monitoring of 37 healthy individuals was done using Holter ECG recorder 'Life card CF' from 'Reynolds Medical'. Heart rate variability in both time and frequency domains was analysed with 'Reynolds Medical Pathfinder Digital/700'. Results: The heart rate variability in normal healthy volunteers of our population was found in time domain using standard deviation of R-R intervals (SDNN), standard deviation of average NN intervals (SDANN), and Square root of the mean squared differences of successive NN intervals (RMSSD). Variation in heart rate variability indices was observed between local and foreign volunteers and RMSSD was found significantly increased (p<0.05) in local population. Conclusions: The values of heart rate variability (RMSSD) in healthy Pakistani volunteers were found increased compared to the foreign data reflecting parasympathetic dominance in our population. (author)

  12. Peak heart rates at extreme altitudes

    DEFF Research Database (Denmark)

    Lundby, C; Van Hall, Gerrit

    2001-01-01

    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...

  13. [Design of Oxygen Saturation, Heart Rate, Respiration Rate Detection System Based on Smartphone of Android Operating System].

    Science.gov (United States)

    Zhu, Mingshan; Zeng, Bixin

    2015-03-01

    In this paper, we designed an oxygen saturation, heart rate, respiration rate monitoring system based on smartphone of android operating system, physiological signal acquired by MSP430 microcontroller and transmitted by Bluetooth module.

  14. FPGA Implementation of Heart Rate Monitoring System.

    Science.gov (United States)

    Panigrahy, D; Rakshit, M; Sahu, P K

    2016-03-01

    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.

  15. Heart rate response to hypoxic exercise

    DEFF Research Database (Denmark)

    Lundby, C; Møller, P; Kanstrup, I L

    2001-01-01

    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...

  16. Heart rate response to hypoxic exercise

    DEFF Research Database (Denmark)

    Lundby, C; Møller, P; Kanstrup, I L

    2001-01-01

    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......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...

  17. QRS peak detection for heart rate monitoring on Android smartphone

    Science.gov (United States)

    Pambudi Utomo, Trio; Nuryani, Nuryani; Darmanto

    2017-11-01

    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.

  18. Spontaneous breathing trial in T-tube negatively impact on autonomic modulation of heart rate compared with pressure support in critically ill patients.

    Science.gov (United States)

    Güntzel Chiappa, Adriana M; Chiappa, Gaspar R; Cipriano, Gerson; Moraes, Ruy S; Ferlin, Elton L; Borghi-Silva, Audrey; Vieira, Silvia R

    2017-07-01

    Spontaneous breathing with a conventional T-piece (TT) connected to the tracheal tube orotraqueal has been frequently used in clinical setting to weaning of mechanical ventilation (MV), when compared with pressure support ventilation (PSV). However, the acute effects of spontaneous breathing with TT versus PSV on autonomic function assessed through heart rate variability (HRV) have not been fully elucidated. The purpose of this study was to examine the acute effects of spontaneous breathing in TT vs PSV in critically ill patients. Twenty-one patients who had received MV for ≥ 48 h and who met the study inclusion criteria for weaning were assessed. Eligible patients were randomized to TT and PSV. Cardiorespiratory responses (respiratory rate -ƒ, tidal volume-V T , mean blood pressure (MBP) and diastolic blood pressure (DBP), end tidal dioxide carbone (P ET CO 2 ), peripheral oxygen saturation (SpO 2 ) and HRV indices in frequency domain (low-LF, high frequency (HF) and LF/HF ratio were evaluated. TT increased ƒ (20 ± 5 vs 25 ± 4 breaths/min, P<0.05), MBP (90 ± 14 vs 94 ± 18 mmHg, P<0.05), HR (90 ± 17 vs 96 ± 12 beats/min, P<0.05), P ET CO 2 (33 ± 8 vs 48 ± 10 mmHg, P<0.05) and reduced SpO 2 (98 ± 1.6 vs 96 ± 1.6%, P<0.05). In addition, LF increased (47 ± 18 vs 38 ± 12 nu, P<0.05) and HF reduced (29 ± 13 vs 32 ± 16 nu, P<0.05), resulting in higher LF/HF ratio (1.62 ± 2 vs 1.18 ± 1, P<0.05) during TT. Conversely, V T increased with PSV (0.58 ± 0.16 vs 0.50 ± 0.15 L, P<0.05) compared with TT. Acute effects of TT mode may be closely linked to cardiorespiratory mismatches and cardiac autonomic imbalance in critically ill patients. © 2015 John Wiley & Sons Ltd.

  19. Resting heart rate, heart rate variability and functional decline in old age.

    Science.gov (United States)

    Ogliari, Giulia; Mahinrad, Simin; Stott, David J; Jukema, J Wouter; Mooijaart, Simon P; Macfarlane, Peter W; Clark, Elaine N; Kearney, Patricia M; Westendorp, Rudi G J; de Craen, Anton J M; Sabayan, Behnam

    2015-10-20

    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. 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 follow-up was 3.2 years. Heart rate and heart rate variability were derived from baseline 10-second electrocardiograms. Heart rate variability was defined as the standard deviation of normal-to-normal RR intervals (SDNN). Functional status in basic (ADL) and instrumental (IADL) activities of daily living was measured using Barthel and Lawton scales, at baseline and during follow-up. The mean age of the study population was 75.3 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 1.12-1.63) higher risk of decline in ADL and IADL, respectively (p for trend heart rate and lower heart rate variability were associated with worse functional status and with higher risk of future functional decline in older adults, independent of cardiovascular disease. This study provides insight into the role of cardiac autonomic function in the development of functional decline. © 2015 Canadian Medical Association or its licensors.

  20. Heart Rate Variability - A Historical Perspective

    Directory of Open Access Journals (Sweden)

    George E Billman

    2011-11-01

    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.

  1. Influence of heavy cigarette smoking on heart rate variability and heart rate turbulence parameters

    DEFF Research Database (Denmark)

    Cagirci, Goksel; Cay, Serkan; Karakurt, Ozlem

    2009-01-01

    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...

  2. Effects of social stress on heart rate and heart rate variability in growing pigs

    NARCIS (Netherlands)

    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

  3. Effects of social stress on heart rate and heart rate variability in growing pigs

    NARCIS (Netherlands)

    Jong, de I.C.; Sgoifo, A.; Lambooij, E.; Korte, S.M.; Blokhuis, H.J.; Koolhaas, J.M.

    2000-01-01

    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

  4. The effects of hypnosis on heart rate variability.

    Science.gov (United States)

    Yüksel, Ramazan; Ozcan, Osman; Dane, Senol

    2013-01-01

    Uslu et al. (2012 ) suggested that hypnotic status can modulate cerebral blood flow. The authors investigated the effects of hypnosis on heart rate variability (HRV). In women, HRV decreased during hypnosis. Posthypnotic values were higher compared to prehypnotic and hypnotic values. Women had highest HRV parameters in the posthypnotic condition. It appears that hypnosis can produce cardiac and cognitive activations. Hypnotherapy may be useful in some cardiac clinical conditions characterized by an autonomic imbalance or some cardiac arrhythmias.

  5. Effects of aerobic training on heart rate

    Directory of Open Access Journals (Sweden)

    Almeida Marcos B.

    2003-01-01

    Full Text Available Regular physical exercise is an important factor to reduce the indexes of cardiovascular and all causes morbimortality. However, there is, apparently, additional and independent benefits of the regular practice of physical exercise and the improvement of the level of aerobic condition. Heart rate (HR is mediated primarily by the direct activity of the autonomic nervous system (ANS, specifically through the sympathetic and parasympathetic branches activities over the sinus node autorhythmicity, with predominance of the vagal activity (parasympathetic at rest, that is progressively inhibited since the onset of the exercise. The HR behavior has been widely studied during different conditions and protocols associated to the exercise. A reduction of the cardiac vagal tone (parasympathetic function and consequently a diminished HR variability in rest, independently of the protocol of measurement used, is related to an autonomic dysfunction, chronic-degenerative diseases and increased mortality risk. Individuals with high levels of aerobic condition have a lower resting HR, along with a larger parasympathetic activity or smaller sympathetic activity, but it is not necessarily a direct consequence of the exercise training, as long as other inherent adaptations to the aerobic conditioning can influence the resting HR. The HR response in the onset of the exercise represents the integrity of the vagus nerve, and the HR recovery on the post-exercise transient also denotes important prognostic information; by the way, individuals that have a slow HR recovery in the first minute post-exercise have increased mortality risk. In conclusion, the physiological mechanisms modulating HR during or after an exercise program are not totally clear, and further studies are needed.

  6. Heart Rate and Increased Intravascular Volume

    Czech Academy of Sciences Publication Activity Database

    Souček, M.; Kára, T.; Jurák, Pavel; Halámek, Josef; Špinarová, L.; Meluzín, J.; Toman, J.; Řiháček, I.; Šumbera, J.; Fráňa, P.

    2003-01-01

    Roč. 52, - (2003), s. 137 - 140 ISSN 0862-8408 R&D Projects: GA ČR GA102/02/1339 Institutional research plan: CEZ:AV0Z2065902 Keywords : kidneys * heart rate * atrial mechanisms Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 0.939, year: 2003

  7. Heart rate variability in bipolar disorder

    DEFF Research Database (Denmark)

    Faurholt-Jepsen, Maria; Kessing, Lars Vedel; Munkholm, Klaus

    2017-01-01

    Background Heart rate variability (HRV) has been suggested reduced in bipolar disorder (BD) compared with healthy individuals (HC). This meta-analysis investigated: HRV differences in BD compared with HC, major depressive disorder or schizophrenia; HRV differences between affective states; HRV...

  8. Heart Rate Fragmentation: A Symbolic Dynamical Approach

    Directory of Open Access Journals (Sweden)

    Madalena D. Costa

    2017-11-01

    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

  9. Parenting Behaviors, Parent Heart Rate Variability, and Their Associations with Adolescent Heart Rate Variability.

    Science.gov (United States)

    Graham, Rebecca A; Scott, Brandon G; Weems, Carl F

    2017-05-01

    Adolescence is a potentially important time in the development of emotion regulation and parenting behaviors may play a role. We examined associations among parenting behaviors, parent resting heart rate variability, adolescent resting heart rate variability and parenting behaviors as moderators of the association between parent and adolescent resting heart rate variability. Ninety-seven youth (11-17 years; 49.5 % female; 34 % African American, 37.1 % Euro-American, 22.6 % other/mixed ethnic background, and 7.2 % Hispanic) and their parents (n = 81) completed a physiological assessment and questionnaires assessing parenting behaviors. Inconsistent discipline and corporal punishment were negatively associated with adolescent resting heart rate variability, while positive parenting and parental involvement were positively associated. Inconsistent discipline and parental involvement moderated the relationship between parent and adolescent resting heart rate variability. The findings provide evidence for a role of parenting behaviors in shaping the development of adolescent resting heart rate variability with inconsistent discipline and parental involvement potentially influencing the entrainment of resting heart rate variability in parents and their children.

  10. Gaussian mixture model of heart rate variability.

    Directory of Open Access Journals (Sweden)

    Tommaso Costa

    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.

  11. Music determines heart rate variability of singers

    Directory of Open Access Journals (Sweden)

    Björn eVickhoff

    2013-07-01

    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.

  12. Heart rate variability - a historical perspective.

    Science.gov (United States)

    Billman, George E

    2011-01-01

    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 HRV. 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 1960s, 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 HRV.

  13. Heart Rate Variability – A Historical Perspective

    Science.gov (United States)

    Billman, George E.

    2011-01-01

    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 HRV. 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 1960s, 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 HRV. PMID:22144961

  14. Early warnings of heart rate deterioration

    OpenAIRE

    Almeida, Vânia G.; Nabney, Ian T.

    2016-01-01

    Hospitals can experience difficulty in detecting and responding to early signs of patient deterioration leading to late intensive care referrals, excess mortality and morbidity, and increased hospital costs. Our study aims to explore potential indicators of physiological deterioration by the analysis of vital-signs. The dataset used comprises heart rate (HR) measurements from MIMIC II waveform database, taken from six patients admitted to the Intensive Care Unit (ICU) and diagnosed with sever...

  15. Does Nasal Obstruction Increase Heart Rate?

    Directory of Open Access Journals (Sweden)

    Venkatesha Belur Keshavamurthy

    2017-12-01

    Full Text Available Introduction  Nasal obstruction is implicated in the etiopathogenesis of Obstructive Sleep Apnea (OSA. OSA is associated with mean heart rate (HR variations in wakefulness and in sleep. Early intervention has proven to reduce cardiovascular morbidity in OSA patients. In spite of various confounding factors HR measurement has been utilised as an independent predictor of mortality. The influence of severity of nasal obstruction on HR has not been studied in the literature. This study aims to clarify the influence of severity of nasal obstruction on HR. Materials and Methods We examined 55 patients aged less than 50 years with no previous cardiac complaints, who underwent overnight oxygen saturation and HR monitoring. The patients were divided into Mild, Moderate and Severe Nasal Obstruction group depending on NOSE scale grading. Results There was no statistically significant difference in the Mean HR, Min HR, Max HR, and Max-Min HR in mild, moderate or severe nasal obstruction groups. Discussion The role of nasal obstruction in Obstructive Sleep Apnoea and the importance of HR as predictor of cardiovascular morbidity have been discussed. The studies on the heart rate in nasal obstruction and OSA were reviewed. Conclusion Nasal obstruction does not influence the heart rate.

  16. Bluetooth Heart Rate Monitors For Spaceflight

    Science.gov (United States)

    Buxton, R. E.; West, M. R.; Kalogera, K. L.; Hanson, A. M.

    2016-01-01

    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

  17. Optically Remote Noncontact Heart Rates Sensing Technique

    Science.gov (United States)

    Thongkongoum, W.; Boonduang, S.; Limsuwan, P.

    2017-09-01

    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.

  18. Combining electroencephalographic activity and instantaneous heart rate for assessing brain–heart dynamics during visual emotional elicitation in healthy subjects

    OpenAIRE

    Valenza, G.; Greco, A.; Gentili, C.; Lanata, A.; Sebastiani, L.; Menicucci, D.; Gemignani, A.; Scilingo, E. P.

    2016-01-01

    Emotion perception, occurring in brain areas such as the prefrontal cortex and amygdala, involves autonomic responses affecting cardiovascular dynamics. However, how such brain–heart dynamics is further modulated by emotional valence (pleasantness/unpleasantness), also considering different arousing levels (the intensity of the emotional stimuli), is still unknown. To this extent, we combined electroencephalographic (EEG) dynamics and instantaneous heart rate estimates to study emotional proc...

  19. Heart Rate and Rhythm and the Benefit of Beta-Blockers in Patients With Heart Failure

    NARCIS (Netherlands)

    Kotecha, Dipak; Flather, Marcus D.; Altman, Douglas G.; Holmes, Jane; Rosano, Giuseppe; Wikstrand, John; Packer, Milton; Coats, Andrew J. S.; Manzano, Luis; Boehm, Michael; van Veldhuisen, Dirk J.; Andersson, Bert; Wedel, Hans; von Lueder, Thomas G.; Rigby, Alan S.; Hjalmarson, Ake; Kjekshus, John; Cleland, John G. F.

    2017-01-01

    BACKGROUND The relationship between mortality and heart rate remains unclear for patients with heart failure with reduced ejection fraction in either sinus rhythm or atrial fibrillation (AF). OBJECTIVES This analysis explored the prognostic importance of heart rate in patients with heart failure

  20. BIOPHYSICAL CHARACTERISATION OF THE UNDER-APPRECIATED AND IMPORTANT RELATIONSHIP BETWEEN HEART RATE VARIABILITY AND HEART RATE

    Science.gov (United States)

    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

    2014-01-01

    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

  1. Sternal Pulse Rate Variability Compared with Heart Rate Variability on Healthy Subjects

    DEFF Research Database (Denmark)

    Chreiteh, Shadi; Belhage, Bo; Hoppe, Karsten

    2014-01-01

    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...... respiration, where the subjects were asked to breathe following a visual scale with a rate of 27 breaths/min. HRV parameters such as the mean intervals (meanNN), the standard deviation of intervals (SDNN), the root mean square of difference of successive intervals (RMSSD), and the proportion of intervals...

  2. Predominance of Intrinsic Mechanism of Resting Heart Rate Control and Preserved Baroreflex Sensitivity in Professional Cyclists after Competitive Training.

    Science.gov (United States)

    Azevedo, Luciene Ferreira; Perlingeiro, Patricia; Hachul, Denise Tessariol; Gomes-Santos, Igor Lucas; Tsutsui, Jeane Mike; Negrao, Carlos Eduardo; De Matos, Luciana D N J

    2016-01-01

    Different season trainings may influence autonomic and non-autonomic cardiac control of heart rate and provokes specific adaptations on heart's structure in athletes. We investigated the influence of transition training (TT) and competitive training (CT) on resting heart rate, its mechanisms of control, spontaneous baroreflex sensitivity (BRS) and relationships between heart rate mechanisms and cardiac structure in professional cyclists (N = 10). Heart rate (ECG) and arterial blood pressure (Pulse Tonometry) were recorded continuously. Autonomic blockade was performed (atropine-0.04 mg.kg-1; esmolol-500 μg.kg-1 = 0.5 mg). Vagal effect, intrinsic heart rate, parasympathetic (n) and sympathetic (m) modulations, autonomic influence, autonomic balance and BRS were calculated. Plasma norepinephrine (high-pressure liquid chromatography) and cardiac structure (echocardiography) were evaluated. Resting heart rate was similar in TT and CT. However, vagal effect, intrinsic heart rate, autonomic influence and parasympathetic modulation (higher n value) decreased in CT (P≤0.05). Sympathetic modulation was similar in both trainings. The autonomic balance increased in CT but still showed parasympathetic predominance. Cardiac diameter, septum and posterior wall thickness and left ventricular mass also increased in CT (Ptrainings. Intrinsic heart rate mechanism is predominant over vagal effect during CT, despite similar resting heart rate. Preserved blood pressure levels and BRS during CT are probably due to similar sympathetic modulation in both trainings.

  3. HEART-RATE-VARIABILITY SPECTRA BASED ON NONEQUIDISTANT SAMPLING - THE SPECTRUM OF COUNTS AND THE INSTANTANEOUS HEART-RATE SPECTRUM

    NARCIS (Netherlands)

    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

  4. Heart and soul: heart rate variability and major depression.

    Science.gov (United States)

    Kidwell, Meyrick; Ellenbroek, Bart A

    2018-04-01

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

  5. Heart rate awareness in patients with chronic stable heart failure. A multi-center observational study.

    LENUS (Irish Health Repository)

    Moran, D

    2014-08-23

    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.

  6. Heart rate and heart rate variability responses to Tai Chi and jogging in Beijing and Graz.

    Science.gov (United States)

    Litscher, Gerhard; Zhang, Weibo; Huang, Tao; Wang, Lu

    2011-02-01

    Tai Chi is a famous training method in China, and jogging is a popular kind of exercise both in Austria and China. Nevertheless, there is little information concerning online monitoring of biosignals during both training activities in parallel. Within the last years innovative scientific monitoring tools for evaluating features of neurocardial fitness have been developed. The goal of this study was to demonstrate heart rate and heart rate variability analysis for the first time during Tai Chi and jogging. Continuous electrocardiographic monitoring over a period of 75 minutes was performed simultaneously in two healthy volunteers using the same type of equipment (medilog AR12 systems). Two healthy persons (both male, 49 years and 52 years, respectively), both hobby sportsmen, were monitored continuously during two resting periods before and after active sport and also during Tai Chi and jogging, respectively. Data acquisition was performed without any technical problems in both subjects. Poincaré plots of sequential R-R intervals (beat to beat variability) show two ellipses of different shape and magnitude. During resting periods blood pressure effects can be clearly seen in one subject (jogging). The same effects, however reduced, are obvious in the other volunteer during Tai Chi. The present investigations during Tai Chi and jogging highlight the potential value of heart rate and heart rate variability monitoring even under difficult conditions. The innovative kind of analysis helps to show how well the human body reacts to sport, stress and recovery.

  7. The effects of caffeine on heart rate variability in newborns with apnea of prematurity.

    Science.gov (United States)

    Ulanovsky, I; Haleluya, N S; Blazer, S; Weissman, A

    2014-08-01

    Apnea of prematurity is a common complication in premature newborns and caffeine is a widespread medication used to treat this complication. Caffeine may have adverse effects on the cardiovascular and central nervous system, yet its effects on the autonomic nervous system modulation of heart rate have not been studied in premature newborns, which was the objective of our study. We prospectively studied 21 premature newborns who were treated with caffeine. We analyzed heart rate variability by power spectral density and by dynamic nonlinear analyses methods. There were no changes in heart rate, blood pressure or the autonomic nervous system tone following administration of caffeine, nor were the nonlinear dynamical properties of the system altered by caffeine. Caffeine does not have detrimental effects on heart rate variability, heart rate or blood pressure in conventional doses given to premature newborns.

  8. Heart rate recovery: Short review of methodology

    Directory of Open Access Journals (Sweden)

    Đurić Biljana

    2016-01-01

    Full Text Available Determination of the heart rate recovery (HRR after the session of a physical activity, represents the valuable parameter for the investigation of autonomic balance and its dynamic in the general population, but also in the population of elite athletes. However, the methodology for its determination and analysis is still not entirely specified. It is necessary to define an adequate protocol of cardiopulmonary exercise test, by choosing an adequate ergometer (treadmill, ergo-bicycle or step bench. Organization of recovery period (active or passive, after the session of exercise is also very important, because its protocol interfered significantly with the value of HRR. Interpretation of obtained HRR values varies a lot, and researcher has freedom to choose the most adequate way, in accordance with the objectives of his study. Following paper represents a short review of determination, interpretation and analysis of HRR, followed by the latest recommendations.

  9. Effects of melatonin and ethanol on the heart rate of Daphnia magna

    Directory of Open Access Journals (Sweden)

    Rebecca Kohn

    2009-01-01

    Full Text Available Melatonin, an endogenous hormone that may regulate circadian rhythms by modulating cholinergic activity, is increasing in popular use as a natural treatment for sleep disorders. However, the effects of melatonin on the human heart are not well characterized, and the consequences of combining alcohol with melatonin are unknown. The myogenic heart of the water flea Daphnia magna (D. magna is regulated by inhibitory cholinergic neurons that modulate cardiac function, including heart rate. D. magna is a useful model organism for cardiovascular function, due to its physical transparency and susceptibility to cardioactive drugs known to affect the human heart. In this study, the effects of immersion in 10 mg/L melatonin and 5% ethanol on the heart rate of D. magna were quantified. Two-hour exposure to melatonin caused a significant decrease in heart rate, from 228 ± 2 bpm to 167 ± 8 bpm. Six-minute immersion in ethanol also significantly depressed the heart rate to 176 ± 10 bpm. Pretreatment with melatonin prior to the addition of ethanol resulted in a greater decrease in heart rate (89 ± 7 bpm than ethanol or melatonin alone. These findings indicate that melatonin and alcohol may combine to cause a greater depressive effect on cardiac function.

  10. Triboelectric Nanogenerator Enabled Body Sensor Network for Self-Powered Human Heart-Rate Monitoring.

    Science.gov (United States)

    Lin, Zhiming; Chen, Jun; Li, Xiaoshi; Zhou, Zhihao; Meng, Keyu; Wei, Wei; Yang, Jin; Wang, Zhong Lin

    2017-09-26

    Heart-rate monitoring plays a critical role in personal healthcare management. A low-cost, noninvasive, and user-friendly heart-rate monitoring system is highly desirable. Here, a self-powered wireless body sensor network (BSN) system is developed for heart-rate monitoring via integration of a downy-structure-based triboelectric nanogenerator (D-TENG), a power management circuit, a heart-rate sensor, a signal processing unit, and Bluetooth module for wireless data transmission. By converting the inertia energy of human walking into electric power, a maximum power of 2.28 mW with total conversion efficiency of 57.9% was delivered at low operation frequency, which is capable of immediately and sustainably driving the highly integrated BSN system. The acquired heart-rate signal by the sensor would be processed in the signal process circuit, sent to an external device via the Bluetooth module, and displayed on a personal cell phone in a real-time manner. Moreover, by combining a TENG-based generator and a TENG-based sensor, an all-TENG-based wireless BSN system was developed, realizing continuous and self-powered heart-rate monitoring. This work presents a potential method for personal heart-rate monitoring, featured as being self-powered, cost-effective, noninvasive, and user-friendly.

  11. Resting and maximal heart rates in ectothermic vertebrates.

    Science.gov (United States)

    Lillywhite, H B; Zippel, K C; Farrell, A P

    1999-12-01

    Resting and maximal heart rates (HR) in ectothermic vertebrates are generally lower than those in endotherms and vary by more than an order of magnitude interspecifically. Variation of HR transcends phylogeny and is influenced by numerous factors including temperature, activity, gas exchange, intracardiac shunts, pH, posture, and reflexogenic regulation of blood pressure. The characteristic resting HR is rarely the intrinsic rate of the pacemaker, which is primarily modulated by cholinergic inhibition and adrenergic excitation in most species. Neuropeptides also appear to be involved in cardiac regulation, although their role is not well understood. The principal determinants of resting HR include temperature, metabolic rate and hemodynamic requirements. Maximal HRs generally do not exceed 120 b min-1, but notable exceptions include the heterothermic tuna and small reptiles having HRs in excess of 300 b min-1 at higher body temperatures. Temperature affects the intrinsic pacemaker rate as well as the relative influence of adrenergic and cholinergic modulation. It also influences the evolved capability to increase HR, with maximal cardiac responses matched to preferred body temperatures in some species. Additional factors either facilitate or limit the maximal level of HR, including: (1) characteristics of the pacemaker potential; (2) development of sarcoplasmic reticulum as a calcium store in excitation-contraction coupling; (3) low-resistance coupling of myocardial cells; (4) limitations of force development imposed by rate changes; (5) efficacy of sympathetic modulation; and (6) development of coronary circulation to enhance oxygen delivery to myocardium. In evolutionary terms, both hemodynamic and oxygen requirements appear to have been key selection pressures for rapid cardiac rates.

  12. Omega-3 Polyunsaturated Fatty Acids and Heart Rate Variability

    Directory of Open Access Journals (Sweden)

    Jeppe Hagstrup Christensen

    2011-11-01

    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

  13. Hierarchical Structure of Heart Rate Variability in Humans

    Science.gov (United States)

    Gao, X. Z.; Ching, E. S. C.; Lin, D. C.

    2004-03-01

    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.

  14. Post-exercise heart-rate recovery correlates to resting heart-rate variability in healthy men.

    Science.gov (United States)

    Molina, Guilherme Eckhardt; Fontana, Keila Elizabeth; Porto, Luiz Guilherme Grossi; Junqueira, Luiz Fernando

    2016-12-01

    The relationship between post-exercise heart-rate recovery (HRR) and resting cardiac autonomic modulation is an incompletely explored issue. To correlate HRR with resting supine and orthostatic autonomic status. HRR at the 1st, 3th, and 5th min following maximal treadmill exercise were correlated with 5-min time-domain (CV, pNN50 and rMSSD) and frequency-domain (TP, LF, HF, LFn, HFn, and LF/HF ratio) indices of heart-rate variability (HRV) in both supine and standing positions in 31 healthy physically active non-athletes men. Statistical analysis employed non-parametric tests with two-tailed p value set at 5 %. Absolute HRR and Δ %HRR at each post-exercise time did not correlated with HRV in supine position, as well as at 1st min in standing position. At the 3rd min and 5th min, these measures negatively correlated with pNN50, rMSSD, TP, and HF indices, and only in the 5th min, they showed negative correlation with HFn and positive correlation with LF, LFn, and LF/HF ratio in the standing position. Coefficient of HRR (CHRR) at the 1st min negatively correlated with pNN50 and rMSSD and at 3rd and 5th min showed positive correlation with LFn and LF/HF ratio in supine position. With HRV indices in standing position CHRR from the 1st to 5th min showed the same respective negative and positive correlations as the other measures. HRR from the 1st to 5th min post-exercise negatively correlated with parasympathetic modulation in resting orthostatic, but showed no correlation in supine position. At the 3rd and 5th min, a positive correlation with combined sympathetic-parasympathetic modulation in both positions was observed.

  15. Genome-wide association studies and resting heart rate

    DEFF Research Database (Denmark)

    Oskari Kilpeläinen, Tuomas

    2016-01-01

    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...

  16. A Signal Processing Module for the Analysis of Heart Sounds and Heart Murmurs

    Science.gov (United States)

    Javed, Faizan; Venkatachalam, P. A.; H, Ahmad Fadzil M.

    2006-04-01

    In this paper a Signal Processing Module (SPM) for the computer-aided analysis of heart sounds has been developed. The module reveals important information of cardiovascular disorders and can assist general physician to come up with more accurate and reliable diagnosis at early stages. It can overcome the deficiency of expert doctors in rural as well as urban clinics and hospitals. The module has five main blocks: Data Acquisition & Pre-processing, Segmentation, Feature Extraction, Murmur Detection and Murmur Classification. The heart sounds are first acquired using an electronic stethoscope which has the capability of transferring these signals to the near by workstation using wireless media. Then the signals are segmented into individual cycles as well as individual components using the spectral analysis of heart without using any reference signal like ECG. Then the features are extracted from the individual components using Spectrogram and are used as an input to a MLP (Multiple Layer Perceptron) Neural Network that is trained to detect the presence of heart murmurs. Once the murmur is detected they are classified into seven classes depending on their timing within the cardiac cycle using Smoothed Pseudo Wigner-Ville distribution. The module has been tested with real heart sounds from 40 patients and has proved to be quite efficient and robust while dealing with a large variety of pathological conditions.

  17. A Signal Processing Module for the Analysis of Heart Sounds and Heart Murmurs

    Energy Technology Data Exchange (ETDEWEB)

    Javed, Faizan; Venkatachalam, P A; H, Ahmad Fadzil M [Signal and Imaging Processing and Tele-Medicine Technology Research Group, Department of Electrical and Electronics Engineering, Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia)

    2006-04-01

    In this paper a Signal Processing Module (SPM) for the computer-aided analysis of heart sounds has been developed. The module reveals important information of cardiovascular disorders and can assist general physician to come up with more accurate and reliable diagnosis at early stages. It can overcome the deficiency of expert doctors in rural as well as urban clinics and hospitals. The module has five main blocks: Data Acquisition and Pre-processing, Segmentation, Feature Extraction, Murmur Detection and Murmur Classification. The heart sounds are first acquired using an electronic stethoscope which has the capability of transferring these signals to the near by workstation using wireless media. Then the signals are segmented into individual cycles as well as individual components using the spectral analysis of heart without using any reference signal like ECG. Then the features are extracted from the individual components using Spectrogram and are used as an input to a MLP (Multiple Layer Perceptron) Neural Network that is trained to detect the presence of heart murmurs. Once the murmur is detected they are classified into seven classes depending on their timing within the cardiac cycle using Smoothed Pseudo Wigner-Ville distribution. The module has been tested with real heart sounds from 40 patients and has proved to be quite efficient and robust while dealing with a large variety of pathological conditions.

  18. Heart rate variability interventions for concussion and rehabilitation

    OpenAIRE

    Conder, Robert L.; Conder, Alanna A.

    2014-01-01

    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 ...

  19. Drowsiness detection using heart rate variability.

    Science.gov (United States)

    Vicente, José; Laguna, Pablo; Bartra, Ariadna; Bailón, Raquel

    2016-06-01

    It is estimated that 10-30 % of road fatalities are related to drowsy driving. Driver's drowsiness detection based on biological and vehicle signals is being studied in preventive car safety. Autonomous nervous system activity, which can be measured noninvasively from the heart rate variability (HRV) signal obtained from surface electrocardiogram, presents alterations during stress, extreme fatigue and drowsiness episodes. We hypothesized that these alterations manifest on HRV and thus could be used to detect driver's drowsiness. We analyzed three driving databases in which drivers presented different sleep-deprivation levels, and in which each driving minute was annotated as drowsy or awake. We developed two different drowsiness detectors based on HRV. While the drowsiness episodes detector assessed each minute of driving as "awake" or "drowsy" with seven HRV derived features (positive predictive value 0.96, sensitivity 0.59, specificity 0.98 on 3475 min of driving), the sleep-deprivation detector discerned if a driver was suitable for driving or not, at driving onset, as function of his sleep-deprivation state. Sleep-deprivation state was estimated from the first three minutes of driving using only one HRV feature (positive predictive value 0.80, sensitivity 0.62, specificity 0.88 on 30 drivers). Incorporating drowsiness assessment based on HRV signal may add significant improvements to existing car safety systems.

  20. Early warnings of heart rate deterioration.

    Science.gov (United States)

    Almeida, Vania G; Nabney, Ian T

    2016-08-01

    Hospitals can experience difficulty in detecting and responding to early signs of patient deterioration leading to late intensive care referrals, excess mortality and morbidity, and increased hospital costs. Our study aims to explore potential indicators of physiological deterioration by the analysis of vital-signs. The dataset used comprises heart rate (HR) measurements from MIMIC II waveform database, taken from six patients admitted to the Intensive Care Unit (ICU) and diagnosed with severe sepsis. Different indicators were considered: 1) generic early warning indicators used in ecosystems analysis (autocorrelation at-1-lag (ACF1), standard deviation (SD), skewness, kurtosis and heteroskedasticity) and 2) entropy analysis (kernel entropy and multi scale entropy). Our preliminary findings suggest that when a critical transition is approaching, the equilibrium state changes what is visible in the ACF1 and SD values, but also by the analysis of the entropy. Entropy allows to characterize the complexity of the time series during the hospital stay and can be used as an indicator of regime shifts in a patient's condition. One of the main problems is its dependency of the scale used. Our results demonstrate that different entropy scales should be used depending of the level of entropy verified.

  1. Cardiovascular Reactivity and Heart Rate Variability in Panic Disorder

    National Research Council Canada - National Science Library

    Santiago, Helen T

    1999-01-01

    .... Because previous studies of cardiovascular reactivity and heart rate variability have been inconclusive, these factors were re-examined in panickers and controls during physiological challenge...

  2. Accuracy of smartphone apps for heart rate measurement.

    Science.gov (United States)

    Coppetti, Thomas; Brauchlin, Andreas; Müggler, Simon; Attinger-Toller, Adrian; Templin, Christian; Schönrath, Felix; Hellermann, Jens; Lüscher, Thomas F; Biaggi, Patric; Wyss, Christophe A

    2017-08-01

    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.

  3. Study Heart Rate by Tools from Complex Networks

    International Nuclear Information System (INIS)

    Makowiec, D.; Wdowczyk-Szulc, J.; Zarczynska-Buchowiecka, M.; Gruchala, M.; Rynkiewicz, A.

    2011-01-01

    Heart rate measured as beat-to-beat time intervals varies in time. It is believed that time intervals between subsequent normal heart contractions carry information about the regulatory system of the heart. How to quantify such signals is not clear and because of that heart rate variability is still apart from the clinic routine. In the following, we propose a method for representing a heart rate signal as a directed network. Then we study the signal properties by complex network tools. The signals to study were collected from patients recovering after the heart transplantation. The aim is to classify the progress of adapting of the new heart - graft. Moreover, it is expected that the method allows for visual classification. Our investigations are preliminary, however the obtained results are promising. (authors)

  4. Heart rate and heart rate variability in dogs with different degrees of myxomatous mitral valve disease

    DEFF Research Database (Denmark)

    Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth

    2011-01-01

    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......-time electrocardiography is seen in dogs with heart failure (HF) secondary to myxomatous mitral valve disease (MMVD). However, HRV is suggested to increase with disease severity at early stages of MMVD. The aims of this study were 1) to associate HR and HRV with severity of MMVD in Cavalier King Charles Spaniels (CKCS......) and 2) to compare HR and HRV between CKCS and other dog breeds in a group of dogs in HF secondary to MMVD. One-hundred dogs were examined by echocardiography and 24-hour electrocardiography. The dogs were divided into five groups: 1) CKCS with no/minimal mitral regurgitation (MR) (MR jet=15% of the left...

  5. Heart rate differentiates urgency and emergency in hypertensive crisis.

    Science.gov (United States)

    Al Bannay, Rashed; Böhm, Michael; Husain, Aysha

    2013-08-01

    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 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.

  6. Reduced intrinsic heart rate is associated with reduced arrhythmic susceptibility in guinea-pig heart.

    Science.gov (United States)

    Osadchii, Oleg E

    2014-12-01

    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.

  7. Mercury Exposure and Heart Rate Variability: A Systematic Review

    Science.gov (United States)

    Gribble, Matthew O.; Cheng, Alan; Berger, Ronald D.; Rosman, Lori; Guallar, Eliseo

    2015-01-01

    Background 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. Design Systematic review. Methods 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. Results We identified 12 studies of mercury exposure and heart rate variability in human populations (10 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. Conclusions 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. PMID:26231507

  8. HEART RATE DURING SLEEP: IMPLICATIONS FOR MONITORING TRAINING STATUS

    Directory of Open Access Journals (Sweden)

    Miriam R. Waldeck

    2003-12-01

    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

  9. Influence of ECG sampling rate in fetal heart rate variability analysis.

    Science.gov (United States)

    De Jonckheere, J; Garabedian, C; Charlier, P; Champion, C; Servan-Schreiber, E; Storme, L; Debarge, V; Jeanne, M; Logier, R

    2017-07-01

    Fetal hypoxia results in a fetal blood acidosis (pHheart rate variability in hypoxic fetuses. So, fetal heart rate variability analysis could be of precious help for fetal hypoxia prediction. Commonly used fetal heart rate variability analysis methods have been shown to be sensitive to the ECG signal sampling rate. Indeed, a low sampling rate could induce variability in the heart beat detection which will alter the heart rate variability estimation. In this paper, we introduce an original fetal heart rate variability analysis method. We hypothesize that this method will be less sensitive to ECG sampling frequency changes than common heart rate variability analysis methods. We then compared the results of this new heart rate variability analysis method with two different sampling frequencies (250-1000 Hz).

  10. Smart Device for the Determination of Heart Rate Variability in Real Time

    Directory of Open Access Journals (Sweden)

    David Naranjo-Hernández

    2017-01-01

    Full Text Available This work presents a first approach to the design, development, and implementation of a smart device for the real-time measurement and detection of alterations in heart rate variability (HRV. The smart device follows a modular design scheme, which consists of an electrocardiogram (ECG signal acquisition module, a processing module and a wireless communications module. From five-minute ECG signals, the processing module algorithms perform a spectral estimation of the HRV. The experimental results demonstrate the viability of the smart device and the proposed processing algorithms.

  11. Do high fetal catecholamine levels affect heart rate variability and ...

    African Journals Online (AJOL)

    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 ...

  12. Retrospective low heart rate variability overview in Jos, Nigeria ...

    African Journals Online (AJOL)

    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 ...

  13. Resting heart rate and cardiovascular events: risk factor or risk ...

    African Journals Online (AJOL)

    syndrome. In 139 194 patients with a non-ST-segment elevated acute coronary syndrome (NONSTEMI), a clear. J-shaped correlation was found between resting heart and all-cause mortality.5 The lowest mortality rate were in patients with resting heart rates between 50 and 70 beats per minute, but mortality doubled when ...

  14. Using photoplethysmography in heart rate monitoring of patients with epilepsy

    NARCIS (Netherlands)

    van Andel, Judith; Ungureanu, Constantin; Aarts, Ronald; Leijten, Frans; Arends, Johan

    2015-01-01

    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

  15. The Correlation Between Ultrasound-Measured Fetal Heart Rate ...

    African Journals Online (AJOL)

    ... for fetal heart rate (FHR) and the relationship between fetal heart rate and gestational age (GA) by 2–D ultrasound. Crown rump length measurement was used for estimating GA in the first trimester while femur length and biparietal diameter measurements were used for estimating GA in the second and third trimesters.

  16. Effects of Malaria on Blood Pressure, Heart Rate, Electrocardiogram ...

    African Journals Online (AJOL)

    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 ...

  17. The Connection between Emotion, Brain Lateralization, and Heart Rate Variability

    Science.gov (United States)

    2005-01-01

    inducing Stroop color word task. ANS reactivity was evaluated using heart rate variability analysis, and CNS reactivity was evaluated using...frequency HRV (parasympathetic activation) as well as increased left frontal brain lateralization. Negative emotions during the Stroop task were... cognitive , and behavioral responses (Taylor, 1991). Among these physiological responses are alterations in heart rate, blood pressure, respiration

  18. Predominance of Intrinsic Mechanism of Resting Heart Rate Control and Preserved Baroreflex Sensitivity in Professional Cyclists after Competitive Training.

    Directory of Open Access Journals (Sweden)

    Luciene Ferreira Azevedo

    Full Text Available Different season trainings may influence autonomic and non-autonomic cardiac control of heart rate and provokes specific adaptations on heart's structure in athletes. We investigated the influence of transition training (TT and competitive training (CT on resting heart rate, its mechanisms of control, spontaneous baroreflex sensitivity (BRS and relationships between heart rate mechanisms and cardiac structure in professional cyclists (N = 10. Heart rate (ECG and arterial blood pressure (Pulse Tonometry were recorded continuously. Autonomic blockade was performed (atropine-0.04 mg.kg-1; esmolol-500 μg.kg-1 = 0.5 mg. Vagal effect, intrinsic heart rate, parasympathetic (n and sympathetic (m modulations, autonomic influence, autonomic balance and BRS were calculated. Plasma norepinephrine (high-pressure liquid chromatography and cardiac structure (echocardiography were evaluated. Resting heart rate was similar in TT and CT. However, vagal effect, intrinsic heart rate, autonomic influence and parasympathetic modulation (higher n value decreased in CT (P≤0.05. Sympathetic modulation was similar in both trainings. The autonomic balance increased in CT but still showed parasympathetic predominance. Cardiac diameter, septum and posterior wall thickness and left ventricular mass also increased in CT (P<0.05 as well as diastolic function. We observed an inverse correlation between left ventricular diastolic diameter, septum and posterior wall thickness and left ventricular mass with intrinsic heart rate. Blood pressure and BRS were similar in both trainings. Intrinsic heart rate mechanism is predominant over vagal effect during CT, despite similar resting heart rate. Preserved blood pressure levels and BRS during CT are probably due to similar sympathetic modulation in both trainings.

  19. Unconstrained monitoring of long-term heart and breath rates during sleep

    International Nuclear Information System (INIS)

    Chen, Wenxi; Zhu, Xin; Wei, Daming; Nemoto, Tetsu; Sugitani, Kayo; Kitamura, Kei-ichiro

    2008-01-01

    An unconstrained method for the long-term monitoring of heart and breath rates during sleep is proposed. The system includes a sensor unit and a web-based network module. The sensor unit is set beneath a pillow to pick up the pressure variations from the head induced by inhalation/exhalation movements and heart pulsation during sleep. The measured pressure signal was digitized and transferred to a remote database server via the network module. A wavelet-based algorithm was employed to detect the heart and breath rates, as well as body movement, during sleep. The overall system was utilized for a total six-month trial operation delivered to a female subject. The profiles of the heart and breath rates on a beat-by-beat and daily basis were obtained. Movements during sleep were also estimated. The results show that the daily average percentage of undetectable periods (UPs) during 881.6 sleep hours over a 180 day period was 17.2%. A total of 89.2% of sleep hours had a UP of not more than 25%. The profile of the heart rate revealed a periodic property that corresponded to the female monthly menstrual cycle. Our system shows promise as a long-term unconstrained monitor for heart and breath rates, and for other physiological parameters related to the quality of sleep and the regularity of the menstrual cycle. (note)

  20. The clinical significance of detection to heart rate deceleration capacity and heart rate variability in patients with chronic heart failure

    Directory of Open Access Journals (Sweden)

    Jiang-rong Zhou

    2015-01-01

    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.

  1. The effect of heart rate on the heart rate variability response to autonomic interventions

    Science.gov (United States)

    Billman, George E.

    2013-01-01

    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. PMID:23986716

  2. The Effect of Heart Rate on the Heart Rate Variability Response to Autonomic Interventions

    Directory of Open Access Journals (Sweden)

    George E Billman

    2013-08-01

    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.

  3. Heart rate and heart rate variability modification in chronic insomnia patients.

    Science.gov (United States)

    Farina, Benedetto; Dittoni, Serena; Colicchio, Salvatore; Testani, Elisa; Losurdo, Anna; Gnoni, Valentina; Di Blasi, Chiara; Brunetti, Riccardo; Contardi, Anna; Mazza, Salvatore; Della Marca, Giacomo

    2014-01-01

    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.

  4. Job strain in relation to ambulatory blood pressure, heart rate, and heart rate variability among female nurses

    NARCIS (Netherlands)

    Riese, H.; Doornen, L.J.P. van; Houtman, I.L.D.; Geus, E.J.C. de

    2004-01-01

    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)

  5. Heart rate variability: a tool to explore the sleeping brain?

    Directory of Open Access Journals (Sweden)

    Florian eChouchou

    2014-12-01

    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.

  6. Heart Rate Variability in Cavalier King Charles Spaniels with Different Degree of Myxomatous Mitral Valve Disease

    DEFF Research Database (Denmark)

    Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth

    2010-01-01

    Heart Rate Variability in Cavalier King Charles Spaniels with Different Degree of Myxomatous Mitral Valve Disease Rasmussen, C.E. 1, Falk, T. 1, Zois, N.E. 1, Moesgaard, S.G. 1, Häggström, J. 2, Pedersen, H.D. 3 and Olsen, L.H1. 1Department of Basic Animal and Veterinary Sciences, Faculty of Life...... Sciences, University of Copenhagen, Frederiksberg, Denmark, 2Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden; and 3Novo Nordic A/S, Maaloev, Denmark. Introduction: Modulation of heart rate by the autonomic nervous system can indirectly be measured by heart rate...... variability (HRV). Reduced HRV is seen in dogs with heart failure secondary to myxomatous mitral valve disease (MMVD). However, HRV is suggested to increase with disease progression in dogs with early stages of MMVD. Comparable results are found in people with primary mitral valve prolapse, a disease...

  7. Learning by Heart: Students Use Heart Rate Patterns To Identify Nervous System Imbalances.

    Science.gov (United States)

    Ackerly, Spafford C.

    2001-01-01

    Introduces a science unit on heart rate variability (HVR) patterns. Uses spectral analysis to determine the effects of environmental stimulants such as music and emotional stress on heart rate. Observes relaxation techniques and their effects on the autonomous nervous system. (Contains 12 references.) (YDS)

  8. Fetal Heart Rate Monitoring from Phonocardiograph Signal Using Repetition Frequency of Heart Sounds

    Directory of Open Access Journals (Sweden)

    Hong Tang

    2016-01-01

    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.

  9. Heating and cooling rates and their effects upon heart rate in the ...

    African Journals Online (AJOL)

    The heating and cooling rates of adult Chersina angulata were investigated to ascertain whether these tortoises can physiologically alter their rates of heat exchange. In addition, heart rates were recorded to provide an insight into the control of heat exchange. C. angulata heats significantly faster than it cools. Heart rates ...

  10. Assesment of Autonomic Function in Metabolic Syndrome using Combination Heart Rate Variability and Heart Rate Turbulence

    Directory of Open Access Journals (Sweden)

    Gülay Aydın

    2013-12-01

    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.

  11. A protocol to study ex vivo mouse working heart at human-like heart rate.

    Science.gov (United States)

    Feng, Han-Zhong; Jin, Jian-Ping

    2018-01-01

    Genetically modified mice are widely used as experimental models to study human heart function and diseases. However, the fast rate of normal mouse heart at 400-600bpm limits its capacity of assessing kinetic parameters that are important for the physiology and pathophysiology of human heart that beats at a much slower rate (75-180bpm). To extend the value of mouse models, we established a protocol to study ex vivo mouse working hearts at a human-like heart rate. In the presence of 300μM lidocaine to lower pacemaker and conductive activities and prevent arrhythmia, a stable rate of 120-130bpm at 37°C is achieved for ex vivo mouse working hearts. The negative effects of decreased heart rate on force-frequency dependence and lidocaine as a myocardial depressant on intracellular calcium can be compensated by using a higher but still physiological level of calcium (2.75mM) in the perfusion media. Multiple parameters were studied to compare the function at the human-like heart rate with that of ex vivo mouse working hearts at the standard rate of 480bpm. The results showed that the conditions for slower heart rate in the presence of 300μM lidocaine did not have depressing effect on left ventricular pressure development, systolic and diastolic velocities and stroke volume with maintained positive inotropic and lusitropic responses to β-adrenergic stimulation. Compared with that at 480bpm, the human-like heart rate increased ventricular filling and end diastolic volume with enhanced Frank-Starling responses. Coronary perfusion was increased from longer relaxation time and interval between beats whereas cardiac efficiency was significantly improved. Although the intrinsic differences between mouse and human heart remain, this methodology for ex vivo mouse hearts to work at human-like heart rate extends the value of using genetically modified mouse models to study cardiac function and human heart diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. "Heart rate-dependent" electrocardiographic diagnosis of left ventricular hypertrophy.

    Science.gov (United States)

    Madias, John E

    2013-05-01

    A case is presented revealing the common phenomenon of heart rate-dependent diagnosis of electrocardiographic (ECG) diagnosis of left ventricular hypertrophy (LVH), which consists of satisfaction of LVH criteria only at faster rates whereas ECGs with a slow heart rate do not satisfy such criteria. The mechanism of the phenomenon has been attributed to the tachycardia-mediated underfilling of the left ventricle bringing the electrical "centroid" of the heart closer to the recording electrodes, which results in augmentation of the amplitude of QRS complexes, particularly in leads V2-V4. ©2012, The Author. Journal compilation ©2012 Wiley Periodicals, Inc.

  13. Resting heart rate is a predictor of mortality in COPD.

    Science.gov (United States)

    Jensen, Magnus Thorsten; Marott, Jacob L; Lange, Peter; Vestbo, Jørgen; Schnohr, Peter; Nielsen, Olav Wendelboe; Jensen, Jan Skov; Jensen, Gorm B

    2013-08-01

    The clinical significance of high heart rate in chronic obstructive pulmonary disease (COPD) is unexplored. We investigated the association between resting heart rate, pulmonary function, and prognosis in subjects with COPD. 16 696 subjects aged ≥40 years from the Copenhagen City Heart Study, a prospective study of the general population, were followed for 35.3 years, 10 986 deaths occurred. Analyses were performed using time-dependent Cox-models and net reclassification index (NRI). Resting heart rate increased with severity of COPD (p85 bpm was 5.5 years without COPD, 9.8 years in mild (Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage I), 6.7 years in moderate (GOLD stage II) and 5.9 years in severe/very severe COPD (GOLD stage III/IV), (pNRI 4.9%, p = 0.01; category less NRI 23.0%, pNRI 7.8%, p = 0.002; category less NRI 24.1%, p<0.0001). Resting heart rate increases with severity of COPD. Resting heart rate is a readily available clinical variable that improves risk prediction in patients with COPD above and beyond that of pulmonary function alone. Resting heart rate may be a potential target for intervention in COPD.

  14. Effect of oxygen treatment on heart rate after abdominal surgery

    DEFF Research Database (Denmark)

    Rosenberg-Adamsen, S; Lie, C; Bernhard, A

    1999-01-01

    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....... 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...... oxygen saturation rate increased significantly from 96% to 99% (P heart rate decreased significantly from 85 beats/min to 81 beats/min (P heart rate occurred...

  15. Modeling baroreflex regulation of heart rate during orthostatic stress

    DEFF Research Database (Denmark)

    Olufsen, Mette; Tran, Hien T.; Ottesen, Johnny T.

    2006-01-01

    During orthostatic stress, arterial and cardiopulmonary baroreflexes play a key role in maintaining arterial pressure by regulating heart rate. This study, presents a mathematical model that can predict the dynamics of heart rate regulation in response to postural change from sitting to standing....... 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...... least squares problem for parameter estimation and successfully demonstrate that our mathematical model can accurately predict heart rate dynamics observed in data obtained from healthy young, healthy elderly, and hypertensive elderly subjects. One of our key findings indicates that to successfully...

  16. Behaviour, heart rate, and heart rate variability in pigs exposed to novelty

    Directory of Open Access Journals (Sweden)

    Manja Zupan

    2016-03-01

    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.

  17. Understanding the physiology of mindfulness: aortic hemodynamics and heart rate variability.

    Science.gov (United States)

    May, Ross W; Bamber, Mandy; Seibert, Gregory S; Sanchez-Gonzalez, Marcos A; Leonard, Joseph T; Salsbury, Rebecca A; Fincham, Frank D

    2016-01-01

    Data were collected to examine autonomic and hemodynamic cardiovascular modulation underlying mindfulness from two independent samples. An initial sample (N = 185) underwent laboratory assessments of central aortic blood pressure and myocardial functioning to investigated the association between mindfulness and cardiac functioning. Controlling for religiosity, mindfulness demonstrated a strong negative relationship with myocardial oxygen consumption and left ventricular work but not heart rate or blood pressure. A second sample (N = 124) underwent a brief (15 min) mindfulness inducing intervention to examine the influence of mindfulness on cardiovascular autonomic modulation via blood pressure variability and heart rate variability. The intervention had a strong positive effect on cardiovascular modulation by decreasing cardiac sympathovagal tone, vasomotor tone, vascular resistance and ventricular workload. This research establishes a link between mindfulness and cardiovascular functioning via correlational and experimental methodologies in samples of mostly female undergraduates. Future directions for research are outlined.

  18. Training-induced bradycardia and intrinsic heart rate in rats.

    Science.gov (United States)

    Nylander, E; Sigvardsson, K; Kilbom, A

    1982-01-01

    After 10 weeks of treadmill training, female Sprague-Dawley rats had developed a bradycardia at exercise on submaximal work loads. This bradycardia was also present after autonomic denervation and in isolated perfused heart preparations. The heart weight/body weight ratio was increased in these trained animals compared to untrained littermates. Sympathectomized, trained rats developed the same degree of cardiac hypertrophy, but their heart rate after denervation and in the isolated heart was the same as in sympathectomized, untrained rats. It is concluded that the bradycardia of trained and thereafter denervated animals seen in this and a previous investigation represents an adaptation within the heart itself, since it was present in the isolated heart. These results thus provide further evidence for a non-neural component in training-induced bradycardia. Since the trained sympathectomized rats had a cardiac hypertrophy but no reduction of intrinsic heart rate, it seems likely that the myocardial mass is of minor importance for the level of intrinsic heart rate.

  19. Measures of and changes in heart rate variability in pediatric heart transplant recipients.

    Science.gov (United States)

    Williams, T; Tang, X; Gilmore, G; Gossett, J; Knecht, K R

    2017-06-01

    Heart rate variability is primarily regulated by the autonomic nervous system. Heart transplant recipients undergo surgical denervation of the graft, which results in interruption of autonomic innervation with resultant diminished heart rate variability although some degree of autonomic control may return. This study aimed to characterize heart rate variability in this population. We report a retrospective review of Holter monitor data from transplanted patients between 2005 and 2013. Studies with significant atrial or ventricular arrhythmias were excluded. We evaluated changes over time and compared standard time domain measures to published pediatric normal values. Data were reviewed from 582 monitors in 152 patients. We found that pediatric heart transplant recipients have lower heart rate variability than age-matched controls and higher average heart rate in recipients older than 3 years. There is an increase in measures of variability through the first 3 years post-transplant with plateau after that time. Surgical technique in regard to interruption of the vagus nerve does not affect variability, nor does underlying congenital vs acquired heart disease. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Signal processing methodologies for an acoustic fetal heart rate monitor

    Science.gov (United States)

    Pretlow, Robert A., III; Stoughton, John W.

    1992-01-01

    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.

  1. Arduino-based noise robust online heart-rate detection.

    Science.gov (United States)

    Das, Sangita; Pal, Saurabh; Mitra, Madhuchhanda

    2017-04-01

    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.

  2. Intrapartum fetal heart rate profiles with and without fetal asphyxia.

    Science.gov (United States)

    Low, J A; Pancham, S R; Worthington, D N

    1977-04-01

    Fetal heart rate profiles for periods up to 12 hours prior to delivery have been reviewed in 515 patients with a fetus at risk. Mechanisms other than fetal asphyxia will cause fetal heart rate decelerations, and fetal asphyxia may in some instances develop in the absence of total or late decelerations. However, an increasing incidence of total decelerations and late decelerations and particularly a marked pattern of total decelerations and late decelerations are of value in the prediction of fetal asphyxia. Fetal heart rate deceleration patterns can predict the probability of fetal asphyxia at the time of initial intervention, while a progression of fetal heart rate deceleration patterns in the individual fetus can be of assistance in the subsequent scheduling of serial acid-base assessments during labor.

  3. Heart Rate Measures of Flight Test and Evaluation

    National Research Council Canada - National Science Library

    Bonner, Malcolm A; Wilson, Glenn F

    2001-01-01

    .... Because flying is a complex task, several measures are required to derive the best evaluation. This article describes the use of heart rate to augment the typical performance and subjective measures used in test and evaluation...

  4. Motion-compensated detection of heart rate based on the time registration adaptive filter

    Science.gov (United States)

    Yang, Lei; Zhou, Jinsong; Jing, Juanjuan; Li, Yacan; Wei, Lidong; Feng, Lei; He, Xiaoying; Bu, Meixia; Fu, Xilu

    2018-01-01

    A non-contact heart rate detection method based on the dual-wavelength technique is proposed and demonstrated experimentally. The heart rate is obtained based on the PhotoPlethysmoGraphy (PPG). Each detection module uses the reflection detection probe which is composed of the LED and the photodiode. It is a well-known fact that the differences in the circuits of two detection modules result in different responses of two modules for motion artifacts. It will cause a time delay between the two signals. This poses a great challenge to compensate the motion artifacts during measurements. In order to solve this problem, we have firstly used the time registration and translated the signals to ensure that the two signals are consistent in time domain. Then the adaptive filter is used to compensate the motion artifacts. Moreover, the data obtained by using this non-contact detection system is compared with those of the conventional finger blood volume pulse (BVP) sensor by simultaneously measuring the heart rate of the subject. During the experiment, the left hand remains stationary and is detected by a conventional finger BVP sensor. Meanwhile, the moving palm of right hand is detected by the proposed system. The data obtained from the proposed non-contact system are consistent and comparable with that of the BVP sensor. This method can effectively suppress the interference caused by the two circuit differences and successfully compensate the motion artifacts. This technology can be used in medical and daily heart rate measurement.

  5. Increased heart rate variability but normal resting metabolic rate in hypocretin/orexin-deficient human narcolepsy.

    NARCIS (Netherlands)

    Fronczek, R.; Overeem, S.; Reijntjes, R.; Lammers, G.J.; Dijk, J.G.M.; Pijl, H.

    2008-01-01

    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

  6. Heart rate and activity profile for young female soccer players

    OpenAIRE

    Barbero Álvarez, José Carlos; Gómez López, Maite; Barbero Álvarez, Verónica; Granda Vera, Juan; Castagna, Carlo

    2008-01-01

    The physical and physiological demands of high-level male soccer have been studied extensively, while few studies have investigated the demands placed on females during match-play, however, there is no information available about the heart rate and activity profile of young female soccer players during match play. Therefore, the aim of this study was to examine cardiovascular (heart-rates HR) and physical demands of young female soccer players during a match. Players were observed during a fr...

  7. Disentangling Respiratory Sinus Arrhythmia in Heart Rate Variability Records

    OpenAIRE

    Topçu, Çağdaş; Frühwirth, Matthias; Moser, Maximilian; Rosenblum, Michael; Pikovsky, Arkady

    2018-01-01

    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...

  8. Accuracy of Heart Rate Watches: Implications for Weight Management.

    Directory of Open Access Journals (Sweden)

    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.

  9. Accuracy of Heart Rate Watches: Implications for Weight Management.

    Science.gov (United States)

    Wallen, Matthew P; Gomersall, Sjaan R; Keating, Shelley E; Wisløff, Ulrik; Coombes, Jeff S

    2016-01-01

    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.

  10. Heart rate variability and baroreflex sensitivity in bilateral lung transplant recipients.

    Science.gov (United States)

    Fontolliet, Timothée; Gianella, Pietro; Pichot, Vincent; Barthélémy, Jean-Claude; Gasche-Soccal, Paola; Ferretti, Guido; Lador, Frédéric

    2018-01-09

    The effects of lung afferents denervation on cardiovascular regulation can be assessed on bilateral lung transplantation patients. The high-frequency component of heart rate variability is known to be synchronous with breathing frequency. Then, if heart beat is neurally modulated by breathing frequency, we may expect disappearance of high frequency of heart rate variability in bilateral lung transplantation patients. On 11 patients and 11 matching healthy controls, we measured R-R interval (electrocardiography), blood pressure (Portapres ® ) and breathing frequency (ultrasonic device) in supine rest, during 10-min free breathing, 10-min cadenced breathing (0·25 Hz) and 5-min handgrip. We analysed heart rate variability and spontaneous variability of arterial blood pressure, by power spectral analysis, and baroreflex sensitivity, by the sequence method. Concerning heart rate variability, with respect to controls, transplant recipients had lower total power and lower low- and high-frequency power. The low-frequency/high-frequency ratio was higher. Concerning systolic, diastolic and mean arterial pressure variability, transplant recipients had lower total power (only for cadenced breathing), low frequency and low-frequency/high-frequency ratio during free and cadenced breathing. Baroreflex sensitivity was decreased. Denervated lungs induced strong heart rate variability reduction. The higher low-frequency/high-frequency ratio suggested that the total power drop was mostly due to high frequency. These results support the hypothesis that neural modulation from lung afferents contributes to the high frequency of heart rate variability. © 2018 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  11. High readmission rate after heart valve surgery

    DEFF Research Database (Denmark)

    Sibilitz, K L; Berg, S K; Thygesen, L C

    2015-01-01

    investigated. RESULTS: After valve surgery, the self-reported health was lower (Short Form-36 (SF-36) Physical Component Scale (PCS): 44.5 vs. 50.6 and Mental Component Scale (MCS): 51.9 vs. 55.0, pClinical signs......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...... of anxiety and depression were present in 13.6% and 13.8%, respectively (Hospital Anxiety and Depression Scale score≥8). Twelve months following discharge, 483 persons (56%) were readmitted. Readmission was associated with lower self-reported health (SF-36 PCS: 46.5 vs. 43.9, and MCS 52.2 vs. 50.7). Higher...

  12. Hydration status after exercise affect resting metabolic rate and heart rate variability.

    Science.gov (United States)

    Castro-Sepulveda, Mauricio; Cerda-Kohler, Hugo; Pérez-Luco, Cristian; Monsalves, Matías; Andrade, David Cristobal; Zbinden-Foncea, Herman; Báez-San Martín, Eduardo; Ramírez-Campillo, Rodrigo

    2014-12-17

    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 (prate, however, only dehydration group ..showed a significant reduction in heart rate variability. More so, the change in resting metabolic rate was significantly higher in dehydration group compared to rehydration group. Hydric homeostasis after exercise affects resting metabolic rate and heart rate variability, highlighting the necessity to control hydration state before resting metabolic rate and heart rate variability assessment. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  13. Evaluation on the influence of electrocardiograph modulated milliampere on image quality and exposure dosage of volume CT heart scan

    International Nuclear Information System (INIS)

    Zhang Sen; Du Xiangke; Li Jianyin

    2006-01-01

    Objective: To find out whether the use of ECG modulated current (mA) will influence image quality and to decide whether the electrocardiograph (ECG) modulated mA will effectively reduce the exposure dosage. Methods: The cardiac pulsating phantom was set at three speed levels, i.e. high, medium, and low speed so as to simulate different heart rates. The phantom was scanned with ECG modulated mA turned on and off, and the exposure dosage of each scan sequence was documented. The images were reconstructed with reconstruction algorithm that matched the different levels of heart rate. CT values and their corresponding standard deviations at uniform areas on the images and the variation of the CT values at different locations were measured. The results from the two groups with and without ECG modulated mA were analyzed. Results: Under the same level of heart rate, the exposure dosage was remarkably reduced when the ECG modulated mA was on than when it was off. Statistical analysis showed no significant difference (P>0.05) between the images from the two groups. Conclusion: When scanning the heart with volume CT (VCT), the application of ECG modulated mA can effectively reduce the exposure dosage without sacrificing the image quality. (authors)

  14. Assessing positive emotional states in dogs using heart rate and heart rate variability.

    Science.gov (United States)

    Zupan, Manja; Buskas, Julia; Altimiras, Jordi; Keeling, Linda J

    2016-03-01

    Since most animal species have been recognized as sentient beings, emotional state may be a good indicator of welfare in animals. The goal of this study was to manipulate the environment of nine beagle research dogs to highlight physiological responses indicative of different emotional experiences. Stimuli were selected to be a more or a less positive food (meatball or food pellet) or social reward (familiar person or less familiar person). That all the stimuli were positive and of different reward value was confirmed in a runway motivation test. Dogs were tested individually while standing facing a display theatre where the different stimuli could be shown by lifting a shutter. The dogs approached and remained voluntarily in the test system. They were tested in four sessions (of 20s each) for each of the four stimuli. A test session consisted of four presentation phases (1st exposure to stimulus, post exposure, 2nd exposure, and access to reward). Heart rate (HR) and heart rate variability (HRV) responses were recorded during testing in the experimental room and also when lying resting in a quiet familiar room. A new method of 'stitching' short periods of HRV data together was used in the analysis. When testing different stimuli, no significant differences were observed in HR and LF:HF ratio (relative power in low frequency (LF) and the high-frequency (HF) range), implying that the sympathetic tone was activated similarly for all the stimuli and may suggest that dogs were in a state of positive arousal. A decrease of HF was associated with the meatball stimulus compared to the food pellet and the reward phase (interacting with the person or eating the food) was associated with a decrease in HF and RMSSD (root mean square of successive differences of inter-beat intervals) compared to the preceding phase (looking at the person or food). This suggests that parasympathetic deactivation is associated with a more positive emotional state in the dog. A similar reduction

  15. Music close to one's heart: heart rate variability with music, diagnostic with e-bra and smartphone

    Science.gov (United States)

    Hegde, Shantala; Kumar, Prashanth S.; Rai, Pratyush; Mathur, Gyanesh N.; Varadan, Vijay K.

    2012-04-01

    Music is a powerful elicitor of emotions. Emotions evoked by music, through autonomic correlates have been shown to cause significant modulation of parameters like heart rate and blood pressure. Consequently, Heart Rate Variability (HRV) analysis can be a powerful tool to explore evidence based therapeutic functions of music and conduct empirical studies on effect of musical emotion on heart function. However, there are limitations with current studies. HRV analysis has produced variable results to different emotions evoked via music, owing to variability in the methodology and the nature of music chosen. Therefore, a pragmatic understanding of HRV correlates of musical emotion in individuals listening to specifically chosen music whilst carrying out day to day routine activities is needed. In the present study, we aim to study HRV as a single case study, using an e-bra with nano-sensors to record heart rate in real time. The e-bra developed previously, has several salient features that make it conducive for this study- fully integrated garment, dry electrodes for easy use and unrestricted mobility. The study considers two experimental conditions:- First, HRV will be recorded when there is no music in the background and second, when music chosen by the researcher and by the subject is playing in the background.

  16. Functionality of the baroreceptor nerves in heart rate regulation

    DEFF Research Database (Denmark)

    Ottesen, Johnny T.; Olufsen, Mette

    2011-01-01

    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...... and show that the coupled model is able to predict heart rate regulation using blood pressure data as an input......Two models describing the afferent baroreceptor firing are analyzed, a basic model predicting firing using a single nonlinear differential equation, and an extended model, coupling K nonlinear responses. Both models respond to the the rate (derivative) and the rate history of the carotid sinus...

  17. Heart Rate Variability Analysis in Patients with Allergic Rhinitis

    Directory of Open Access Journals (Sweden)

    Ming-Ying Lan

    2013-01-01

    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.

  18. Effect of immersion, submersion, and scuba diving on heart rate variability

    OpenAIRE

    Schipke, J; Pelzer, M

    2001-01-01

    Background—Heart rate variability (HRV) describes the cyclic variations in heart rate and offers a non-invasive tool for investigating the modulatory effects of neural mechanisms elicited by the autonomic nervous system on intrinsic heart rate.

  19. Changes in heart rate and heart rate variability as a function of age in Thoroughbred horses.

    Science.gov (United States)

    Ohmura, Hajime; Jones, James H

    2017-01-01

    We investigated changes in heart rate (HR) and HR variability as a function of age in newborn foals to old Thoroughbred horses. Experiments were performed on a total of 83 healthy and clinically normal Thoroughbred horses. Resting HR decreased with age from birth. The relationship between age and HR fit the equation Y=48.2X -0.129 (R 2 =0.705); the relationship between age and HR for horses 0-7 years old fit the equation Y=44.1X -0.179 (R 2 =0.882). Seven-day-old horses had the highest HR values (106 ± 10.3 beat/min). The low frequency (LF) and high frequency (HF) powers increased with age in newborn to old horses. These changes in HR and HR variability appear to result from the effects of ageing. Three- to seven-year-old race horses had the lowest HR values (32.9 ± 3.5 beat/min) and the highest LF and HF powers except for the HF powers in the oldest horses. Race training may have contributed to these changes. Horses of ages greater than 25 years old had the highest HF powers and the lowest LF/HF ratios. In individual horses, 8 of the 15 horses over 25 years old had LF/HF ratios of less than 1.0; their HR variability appears to be unique, and they may have a different autonomic balance than horses of younger age.

  20. Working memory load modulates microsaccadic rate.

    Science.gov (United States)

    Dalmaso, Mario; Castelli, Luigi; Scatturin, Pietro; Galfano, Giovanni

    2017-03-01

    Microsaccades are tiny eye movements that individuals perform unconsciously during fixation. Despite that the nature and the functions of microsaccades are still lively debated, recent evidence has shown an association between these micro eye movements and higher order cognitive processes. Here, in two experiments, we specifically focused on working memory and addressed whether differential memory load could be reflected in a modulation of microsaccade dynamics. In Experiment 1, participants memorized a numerical sequence composed of either two (low-load condition) or five digits (high-load condition), appearing at fixation. The results showed a reduction in the microsaccadic rate in the high-load compared to the low-load condition. In Experiment 2, five red or green digits were always presented at fixation. Participants either memorized the color (low-load condition) or the five digits (high-load condition). Hence, visual stimuli were exactly the same in both conditions. Consistent with Experiment 1, microsaccadic rate was lower in the high-load than in the low-load condition. Overall, these findings reveal that an engagement of working memory can have an impact on microsaccadic rate, consistent with the view that microsaccade generation is pervious to top-down processes.

  1. Resting Heart Rate Is Not Associated with Cognitive Function

    DEFF Research Database (Denmark)

    Wod, Mette; Jensen, Magnus Thorsten; Galatius, Søren

    2018-01-01

    Aims: In order to examine the hypothesis that elevated resting heart rate (RHR) is associated with impaired cognitive score, we investigated the relationship between RHR and cognitive score in middle-aged, elderly and old Danish subjects from the general population. Methods: Composite cognitive...... heart conditions and hypertension. RHR was assessed by palpating radial pulse. Genetic and shared environmental confounding was addressed in intrapair analyses of 2,049 twin pairs. Results: In unadjusted multivariate models and in multivariable models adjusting for age, sex, heart conditions...

  2. Heart rate variability measure in breast cancer patients and survivors: A systematic review.

    Science.gov (United States)

    Arab, Claudia; Dias, Daniel Penteado Martins; Barbosa, Renata Thaís de Almeida; Carvalho, Tatiana Dias de; Valenti, Vitor Engrácia; Crocetta, Tânia Brusque; Ferreira, Marcelo; Abreu, Luiz Carlos de; Ferreira, Celso

    2016-06-01

    In the current study, we aimed to review literature findings showing the clinical importance of cardiac autonomic modulation assessed by heart rate variability analysis in breast cancer (BC) patients and survivors. We conducted a systematic review according to The PRISMA Statement in Medline, Scopus and Web of Science (_-2015) databases. The search was limited to articles in English language, published in peer-reviewed journals, and with adult age samples only (e.g., women, patients, or survivors, diagnosed with BC in any stage). We included observational studies and randomized trials. Detailed heart rate variability analysis (instruments, data collection protocol, and analysis methods) was required. Search terms included autonomic nervous system, heart rate variability, sympathetic and parasympathetic nervous system, autonomic dysfunction, vagal nervous and breast neoplasms, breast cancer and breast tumor. Twelve studies were included in this review. The clinical importance of cardiac autonomic modulation assessed by heart rate variability analysis in BC patients and survivors is demonstrated by association with effects of BC surgery, and treatments, and the adverse effects of surgery and treatments on survivors (e.g., cardiotoxicity, fatigue, and stress). The strength of evidence of included studies is low: small samples size and heterogeneity, presence of confounders, and observational studies design. The heart rate variability analysis could be used as a complementary non-invasive tool for the early diagnosis and better prognosis of autonomic dysfunction, and survival in BC patients. There are many potential clinical applications of heart rate variability analysis in BC patients, and the employment of such approaches could lead to lower impairment of autonomic function in this individuals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Entropies, Partitionings and Heart Rate Variability

    Czech Academy of Sciences Publication Activity Database

    Paluš, Milan; Zebrowski, J.

    2009-01-01

    Roč. 51, č. 2 (2009), s. 65-72 ISSN 0001-7604 Institutional research plan: CEZ:AV0Z10300504 Keywords : coarse-grained entropy rate * HR variability * entropy Subject RIV: BB - Applied Statistics, Operational Research http://www.activitas.org/index.php/nervosa/article/view/25

  4. Evaluation of the metabolic rate based on the recording of the heart rate

    OpenAIRE

    MALCHAIRE, Jacques; ALFANO, Francesca Romana d?AMBROSIO; PALELLA, Boris Igor

    2017-01-01

    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...

  5. Sleep-Wakefulness Determinations from Heart Rate Data.

    Science.gov (United States)

    1978-08-01

    then returns toward quiescence with deepeninQ sleep . The almost complete body paralysis during REM periods exists in sharp contrast to the violent...7RD-A139 436 SLEEP -NAKEFULNESS DETERMINATIONS FROM HEART RTE DATA i/i(U) TEXAS UNIV AT AUSTIN ELECTRONICS RESEARCH CENTER PCRICHARDSON ET AL- AUG...LM MICROCOPY RESOLUTION TEST CHART WATONAL SU(A~J OF STADIOARDS - A143 ,, . , I" _ _ AD -" SLEEP -WAKEFULNESS DETERMINATIONS FROM HEART RATE DATA

  6. Rate modulation detection thresholds for cochlear implant users.

    Science.gov (United States)

    Brochier, Tim; McKay, Colette; McDermott, Hugh

    2018-02-01

    The perception of temporal amplitude modulations is critical for speech understanding by cochlear implant (CI) users. The present study compared the ability of CI users to detect sinusoidal modulations of the electrical stimulation rate and current level, at different presentation levels (80% and 40% of the dynamic range) and modulation frequencies (10 and 100 Hz). Rate modulation detection thresholds (RMDTs) and amplitude modulation detection thresholds (AMDTs) were measured and compared to assess whether there was a perceptual advantage to either modulation method. Both RMDTs and AMDTs improved with increasing presentation level and decreasing modulation frequency. RMDTs and AMDTs were correlated, indicating that a common processing mechanism may underlie the perception of rate modulation and amplitude modulation, or that some subject-dependent factors affect both types of modulation detection.

  7. Autonomic control of heart rate after exercise in trained wrestlers.

    Science.gov (United States)

    Henríquez, Olguín C; Báez, San Martín E; Von Oetinger, A; Cañas, Jamett R; Ramírez, Campillo R

    2013-06-01

    The objective of this study was to establish differences in vagal reactivation, through heart rate recovery and heart rate variability post exercise, in Brazilian jiu-jitsu wrestlers (BJJW). A total of 18 male athletes were evaluated, ten highly trained (HT) and eight moderately trained (MT), who performed a maximum incremental test. At the end of the exercise, the R-R intervals were recorded during the first minute of recovery. We calculated heart rate recovery (HRR60s), and performed linear and non-linear (standard deviation of instantaneous beat-to-beat R-R interval variability - SD1) analysis of heart rate variability (HRV), using the tachogram of the first minute of recovery divided into four segments of 15 s each (0-15 s, 15-30 s, 30-45 s, 45-60 s). Between HT and MT individuals, there were statistically significant differences in HRR60s (p <0.05) and in the non linear analysis of HRV from SD130-45s (p <0.05) and SD145-60s (p <0.05). The results of this research suggest that heart rate kinetics during the first minute after exercise are related to training level and can be used as an index for autonomic cardiovascular control in BJJW.

  8. AUTONOMIC CONTROL OF HEART RATE AFTER EXERCISE IN TRAINED WRESTLERS

    Directory of Open Access Journals (Sweden)

    Carlos F Henríquez

    2013-04-01

    Full Text Available The objective of this study was to establish differences in vagal reactivation, through heart rate recovery and heart rate variability post exercise, in Brazilian jiu-jitsu wrestlers (BJJW. A total of 18 male athletes were evaluated, ten highly trained (HT and eight moderately trained (MT, who performed a maximum incremental test. At the end of the exercise, the R-R intervals were recorded during the first minute of recovery. We calculated heart rate recovery (HRR60s, and performed linear and non-linear (standard deviation of instantaneous beat-to-beat R-R interval variability – SD1 analysis of heart rate variability (HRV, using the tachogram of the first minute of recovery divided into four segments of 15 s each (0-15 s, 15-30 s, 30-45 s, 45-60 s. Between HT and MT individuals, there were statistically significant differences in HRR60s (p <0.05 and in the non linear analysis of HRV from SD130-45s (p <0.05 and SD145-60s (p <0.05. The results of this research suggest that heart rate kinetics during the first minute after exercise are related to training level and can be used as an index for autonomic cardiovascular control in BJJW.

  9. Heart rate measurement based on face video sequence

    Science.gov (United States)

    Xu, Fang; Zhou, Qin-Wu; Wu, Peng; Chen, Xing; Yang, Xiaofeng; Yan, Hong-jian

    2015-03-01

    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.

  10. Heart rate-based lactate minimum test: a reproducible method.

    NARCIS (Netherlands)

    Strupler, M.; Muller, G.; Perret, C.

    2009-01-01

    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

  11. The Use of Heart Rate Monitors in Physical Education

    Science.gov (United States)

    Nichols, Randall; Davis, Kathryn L.; McCord, Tim; Schmidt, Dave; Slezak, Alex M.

    2009-01-01

    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…

  12. QT measurement and heart rate correction during hypoglycemia

    DEFF Research Database (Denmark)

    Christensen, Toke Folke; Randløv, Jette; Christensen, Leif Engmann

    2010-01-01

    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...... induced by intravenous injection of two insulin types in a cross-over design. QT measurements were done using the slope-intersect (SI) and manual annotation (MA) methods. Heart rate correction was done using Bazett's (QTcB) and Fridericia's (QTcF) formulas. Results. The SI method showed significant...... a significant impact on the prolongation of QT during hypoglycemia. Heart rate correction may also influence the QT during hypoglycemia while the type of insulin is insignificant. Prolongation of QTc in this study did not reach pathologic values suggesting that QTc prolongation cannot fully explain the dead...

  13. Heart rate variability in male patients with metabolic syndrome

    Directory of Open Access Journals (Sweden)

    A E Kratnov

    2013-03-01

    Full Text Available Aim. To study the heart rate variability via 24-hours ECG monitoring in male patients with metabolic syndrome (MS and no signs of ischemic heart disease (IHD.Materials and Methods. 131 males aged 29 to 60 years with no evidence for IHD were enrolled for this study and underwent 24-hoursECG monitoring procedure.Results. We determined that MS in males is associated with dysautonomia, accompanied by decrease in sympathetic heart stimulation (specifically, in LF and VLF parameters and left ventricular diastolic abnormalities that correlate with abdominal obesity. Conclusion. MS in males is associated with dysautonomia, accompanied by decrease in sympathetic heart stimulation (specifically, in LF and VLF parameters and left ventricular diastolic abnormalities that correlate with abdominal obesity.

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

    Directory of Open Access Journals (Sweden)

    Juan Bolea

    2016-11-01

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

  15. Heart rate variability and muscle sympathetic nerve activity response to acute stress: the effect of breathing

    OpenAIRE

    DeBeck, Lindsay D.; Petersen, Stewart R.; Jones, Kelvin E.; Stickland, Michael K.

    2010-01-01

    Previous research has suggested a relationship between low-frequency power of heart rate variability (HRV; LF in normalized units, LFnu) and muscle sympathetic nerve activity (MSNA). However, investigations have not systematically controlled for breathing, which can modulate both HRV and MSNA. Accordingly, the aims of this experiment were to investigate the possibility of parallel responses in MSNA and HRV (LFnu) to selected acute stressors and the effect of controlled breathing. After data w...

  16. Attenuated Heart Rate Response is Associated with Hypocretin Deficiency in Patients with Narcolepsy

    DEFF Research Database (Denmark)

    Sørensen, Gertrud Laura; Knudsen, Stine; Petersen, Eva Rosa

    2013-01-01

    Our results show that autonomic dysfunction is part of the narcoleptic phenotype, and that hypocretin-1 deficiency is the primary predictor of this dysfunction. This finding suggests that the hypocretin system participates in the modulation of cardiovascular function at rest. CITATION: Sorensen GL......; Knudsen S; Petersen ER; Kempfner J; Gammeltoft S; Sorensen HBD; Jennum P. Attenuated heart rate response is associated with hypocretin deficiency in patients with narcolepsy. SLEEP 2013;36(1):91-98....

  17. A healthy heart is not a metronome: an integrative review of the heart's anatomy and heart rate variability

    OpenAIRE

    Shaffer, Fred; McCraty, Rollin; Zerr, Christopher L.

    2014-01-01

    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 fr...

  18. Peak heart rate decreases with increasing severity of acute hypoxia

    DEFF Research Database (Denmark)

    Lundby, C; Araoz, M; Van Hall, Gerrit

    2001-01-01

    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...

  19. Robust efficient estimation of heart rate pulse from video

    Science.gov (United States)

    Xu, Shuchang; Sun, Lingyun; Rohde, Gustavo Kunde

    2014-01-01

    We describe a simple but robust algorithm for estimating the heart rate pulse from video sequences containing human skin in real time. Based on a model of light interaction with human skin, we define the change of blood concentration due to arterial pulsation as a pixel quotient in log space, and successfully use the derived signal for computing the pulse heart rate. Various experiments with different cameras, different illumination condition, and different skin locations were conducted to demonstrate the effectiveness and robustness of the proposed algorithm. Examples computed with normal illumination show the algorithm is comparable with pulse oximeter devices both in accuracy and sensitivity. PMID:24761294

  20. Reiki improves heart rate homeostasis in laboratory rats.

    Science.gov (United States)

    Baldwin, Ann Linda; Wagers, Christina; Schwartz, Gary E

    2008-05-01

    To determine whether application of Reiki to noise-stressed rats can reduce their heart rates (HRs) and blood pressures. In a previous study, we showed that exposure of rats to 90 dB white noise for 15 minutes caused their HRs and blood pressures to significantly increase. Reiki has been shown to significantly decrease HR and blood pressure in a small group of healthy human subjects. However, use of humans in such studies has the disadvantage that experimental interpretations are encumbered by the variable of belief or skepticism regarding Reiki. For that reason, noise-stressed rats were used as an animal model to test the efficacy of Reiki in reducing elevated HR and blood pressure. Three unrestrained, male Sprague-Dawley rats implanted with radiotelemetric transducers were exposed daily for 8 days to a 15-minute white noise regimen (90 dB). For the last 5 days, the rats received 15 minutes of Reiki immediately before the noise and during the noise period. The experiment was repeated on the same animals but using sham Reiki. The animals were housed in a quiet room in University of Arizona Animal Facility. Mean HRs and blood pressure were determined before Reiki/sham Reiki, during Reiki/sham Reiki, and during the noise in each case. Reiki, but not sham Reiki, significantly reduced HR compared to initial values. With Reiki, there was a high correlation between change in HR and initial HR, suggesting a homeostatic effect. Reiki, but not sham Reiki, significantly reduced the rise in HR produced by exposure of the rats to loud noise. Neither Reiki nor sham Reiki significantly affected blood pressure. Reiki is effective in modulating HR in stressed and unstressed rats, supporting its use as a stress-reducer in humans.

  1. Predictive value of casual ECG-based resting heart rate compared with resting heart rate obtained from Holter recording

    DEFF Research Database (Denmark)

    Carlson, Nicholas; Dixen, Ulrik; Marott, Jacob L

    2014-01-01

    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...... HRs recorded and mean HR calculated from all daytime HRs. Follow-up was recorded from public registers. Outcome measure was hazard rate for the combined endpoint of cardiovascular mortality, non-fatal heart failure and non-fatal acute myocardial infarction. Comparison of casual RHR, Holter RHR...... was found to be marginally superior as a predictor of cardiovascular morbidity and mortality. The results presented here do not however warrant the abandonment of a tested epidemiological variable....

  2. Asymmetric acceleration/deceleration dynamics in heart rate variability

    Science.gov (United States)

    Alvarez-Ramirez, J.; Echeverria, J. C.; Meraz, M.; Rodriguez, E.

    2017-08-01

    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 cardiovascular regulatory dynamics.

  3. Heart Rate Variability Is Associated with Exercise Capacity in Patients with Cardiac Syndrome X

    Science.gov (United States)

    Cheng, Hao-Min; Yu, Wen-Chung; Chen, Chen-Huan

    2016-01-01

    Heart rate variability (HRV) reflects the healthiness of autonomic nervous system, which is associated with exercise capacity. We therefore investigated whether HRV could predict the exercise capacity in the adults with cardiac syndrome X (CSX). A total of 238 subjects (57±12 years, 67.8% men), who were diagnosed as CSX by the positive exercise stress test and nearly normal coronary angiogram were enrolled. Power spectrum from the 24-hour recording of heart rate was analyzed in frequency domain using total power (TP) and spectral components of the very low frequency (VLF), low frequency (LF) and high frequency (HF) ranges. Among the study population, 129 subjects with impaired exercise capacity during the treadmill test had significantly lower HRV indices than those with preserved exercise capacity (≥90% of the age predicted maximal heart rate). After accounting for age, sex, and baseline SBP and heart rate, VLF (odds ratio per 1SD and 95% CI: 2.02, 1.19–3.42), LF (1.67, 1.10–2.55), and TP (1.82, 1.17–2.83) remained significantly associated with preserved exercise capacity. In addition, increased HRV indices were also associated with increased exercise duration, rate-pressure product, and heart rate recovery, independent of age, body mass index, and baseline SBP and heart rate. In subgroup analysis, HRV indices demonstrated similar predictive values related to exercise capacity across various subpopulations, especially in the young. In patients with CSX, HRV was independently associated with exercise capacity, especially in young subjects. The healthiness of autonomic nervous system may have a role in modulating the exercise capacity in patients with CSX. PMID:26812652

  4. Inhalation of ultrafine carbon particles alters heart rate and heart rate variability in people with type 2 diabetes.

    Science.gov (United States)

    Vora, Rathin; Zareba, Wojciech; Utell, Mark J; Pietropaoli, Anthony P; Chalupa, David; Little, Erika L; Oakes, David; Bausch, Jan; Wiltshire, Jelani; Frampton, Mark W

    2014-07-16

    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.

  5. Relative influence of age, resting heart rate and sedentary life style in short-term analysis of heart rate variability

    OpenAIRE

    E.R. Migliaro; P. Contreras; S. Bech; A. Etxagibel; M. Castro; R. Ricca; K. Vicente

    2001-01-01

    In order to assess the relative influence of age, resting heart rate (HR) and sedentary life style, heart rate variability (HRV) was studied in two different groups. The young group (YG) consisted of 9 sedentary subjects aged 15 to 20 years (YG-S) and of 9 nonsedentary volunteers (YG-NS) also aged 15 to 20. The elderly sedentary group (ESG) consisted of 16 sedentary subjects aged 39 to 82 years. HRV was assessed using a short-term procedure (5 min). R-R variability was calculated in the time-...

  6. Evaluation of the metabolic rate based on the recording of the heart rate.

    Science.gov (United States)

    Malchaire, Jacques; d'AMBROSIO Alfano, Francesca Romana; Palella, Boris Igor

    2017-06-08

    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%.

  7. E-bra with nanosensors, smart electronics and smart phone communication network for heart rate monitoring

    Science.gov (United States)

    Varadan, Vijay K.; Kumar, Prashanth S.; Oh, Sechang; Mathur, Gyanesh N.; Rai, Pratyush; Kegley, Lauren

    2011-04-01

    Heart related ailments have been a major cause for deaths in both men and women in United States. Since 1985, more women than men have died due to cardiac or cardiovascular ailments for reasons that are not well understood as yet. Lack of a deterministic understanding of this phenomenon makes continuous real time monitoring of cardiovascular health the best approach for both early detection of pathophysiological changes and events indicative of chronic cardiovascular diseases in women. This approach requires sensor systems to be seamlessly mounted on day to day clothing for women. With this application in focus, this paper describes a e-bra platform for sensors towards heart rate monitoring. The sensors, nanomaterial or textile based dry electrodes, capture the heart activity signals in form Electrocardiograph (ECG) and relay it to a compact textile mountable amplifier-wireless transmitter module for relay to a smart phone. The ECG signal, acquired on the smart phone, can be transmitted to the cyber space for post processing. As an example, the paper discusses the heart rate estimation and heart rate variability. The data flow from sensor to smart phone to server (cyber infrastructure) has been discussed. The cyber infrastructure based signal post processing offers an opportunity for automated emergency response that can be initiated from the server or the smartphone itself. Detailed protocols for both the scenarios have been presented and their relevance to the present emergency healthcare response system has been discussed.

  8. Sleep Wakefulness Determinations From Heart Rate Data. Volume III.

    Science.gov (United States)

    1977-05-31

    wakefulness and sleep. Psvchophyslol., 10:488-500, 1973. 66. Petre-Quadens, O., de Lee , C: Eye-movements during sleep: a common criterion of...INSTANTANEOUS HEART RATES FIGURE I L 96 terms of a rouch measure of their length, the number of intervals between the Instantaneous HR values

  9. Heart rate differences in small sided games in formative basketball

    Directory of Open Access Journals (Sweden)

    Fernando Gracia

    2014-03-01

    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:

  10. Continuous measurement of heart rate variability following carbon ...

    African Journals Online (AJOL)

    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, ...

  11. Heart rate variability | Lutfi | Sudan Journal of Medical Sciences

    African Journals Online (AJOL)

    An important outcome of such analysis is heart rate variability (HRV), which is widely accepted to have prognostic significance in patients with cardiovascular diseases especially after acute myocardial infarction. This is because HRV represents one of the most helpful markers of autonomic balance and hence can predict ...

  12. The effect of exercise and lifestyle interventions on heart rate ...

    African Journals Online (AJOL)

    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 ...

  13. Mechanisms of initial heart rate response to postural change

    NARCIS (Netherlands)

    Borst, C.; Wieling, W.; van Brederode, J. F.; Hond, A.; de Rijk, L. G.; Dunning, A. J.

    1982-01-01

    We explored in 43 healthy subjects the afferent mechanisms of the initial heart rate response to standing by comparing free standing, 70 degrees head-up tilt, handgrip, and contraction of abdominal and leg muscles. The results indicate the following. 1) Standing evokes an immediate, large, bimodal

  14. Effects of Interval Training Programme on Resting Heart Rate in ...

    African Journals Online (AJOL)

    DATONYE ALASIA

    4 and Department of Radiology,Federal Medical Center, Owerri, Nigeria. ABSTRACT. Background: Heart rate (HR) is a determinant of cardiovascular event risk in patient with hypertension. The primary purpose of the present study was to investigate the effect of interval training program on HR in black African subjects with.

  15. Anti-Hyperlipidaemic and Heart Rate Lowering Effects of Aqueous ...

    African Journals Online (AJOL)

    The anti-hyperlipidaemic and heart rate lowering potential of aqueous leaf extract of Viscum album (mistletoe) in hypercholesterolaemic rats was investigated in this study. The lethality studies showed that the aqueous extract of the plant had an LD50 value of 452.20mg/kg by intraperitoneal route. There were significant ...

  16. Entertainment Capture through Heart Rate Activity in Physical Interactive Playgrounds

    DEFF Research Database (Denmark)

    Yannakakis, Georgios; Hallam, John; Lund, Henrik Hautop

    2008-01-01

    children’s physiological signals, an estimator of the degree to which games provided by the playground engage the players. For this purpose children’s heart rate (HR) signals, and their expressed preferences of how much “fun” particular game variants are, are obtained from experiments using games...

  17. Continuous measurement of heart rate variability following carbon ...

    African Journals Online (AJOL)

    2010-07-16

    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 ...

  18. Blood pressure and heart rate adjustment following acute Frenkel's ...

    African Journals Online (AJOL)

    Background: Frenkel's ambulatory activity has been routinely employed by physiotherapists for rehabilitation of gait coordination, however, its immediate influence on blood pressure and heart rate has not been investigated. Objective: To investigate the acute effect of Frenkel's ambulatory activity on blood pressure and ...

  19. Prediction of maximal heart rate: comparison using a novel and ...

    African Journals Online (AJOL)

    Prediction of maximal heart rate: comparison using a novel and conventional equation. LR Keytel, E Mukwevho, MA Will, M Lambert. Abstract. No Abstract. African Journal for Physical, Health Education, Recreation and Dance Vol. 11(3) 2005: 269-277. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL ...

  20. Muscle metaboreflex and autonomic regulation of heart rate in humans

    DEFF Research Database (Denmark)

    Fisher, James P; Adlan, Ahmed M; Shantsila, Alena

    2013-01-01

    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...

  1. Heart rate variability is reduced during acute uncomplicated diverticulitis

    DEFF Research Database (Denmark)

    Huang, Chenxi; Alamili, Mahdi; Rosenberg, Jacob

    2016-01-01

    BACKGROUND: The aim of the present study was to report the trajectory of heart rate variability (HRV) indices during a low-grade acute inflammation and their associations to biomarkers for infection. METHODS: Twelve patients with uncomplicated acute diverticulitis completed this observational study...

  2. Simplifying cardiovascular risk estimation using resting heart rate.

    LENUS (Irish Health Repository)

    Cooney, Marie Therese

    2010-09-01

    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.

  3. Decreased heart rate variability in surgeons during night shifts

    DEFF Research Database (Denmark)

    Amirian, Ilda; Toftegård Andersen, Lærke; Rosenberg, Jacob

    2014-01-01

    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'...

  4. Heart Rate Variability and Drawing Impairment in Hypoxemic COPD

    Science.gov (United States)

    Incalzi, Raffaele Antonelli; Corsonello, Andrea; Trojano, Luigi; Pedone, Claudio; Acanfora, Domenico; Spada, Aldo; D'Addio, Gianni; Maestri, Roberto; Rengo, Franco; Rengo, Giuseppe

    2009-01-01

    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…

  5. Heart Rate Variability: Effect of Exercise Intensity on Postexercise Response

    Science.gov (United States)

    James, David V. B.; Munson, Steven C.; Maldonado-Martin, Sara; De Ste Croix, Mark B. A.

    2012-01-01

    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…

  6. Allostatic load and heart rate variability as health risk indicators ...

    African Journals Online (AJOL)

    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 ...

  7. The intubating laryngeal mask produces less heart rate response to ...

    African Journals Online (AJOL)

    Pc

    We compared heart rate and blood pressure changes to intubation produced by conventional laryngoscopic-guided intubation to those produced by blind intubation through the intubating laryngeal mask (ILM) in normotensive adults with normal airways. Forty paralysed, anaesthetised adults undergoing elective surgery ...

  8. Relationship between Exercise Heart Rate and Music Tempo Preference

    Science.gov (United States)

    Karageorghis, Costas I.; Jones, Leighton; Low, Daniel C.

    2006-01-01

    The present study examined the predicted positive and linear relationship (Iwanaga, 1995a, 1995b) between exercise heart rate and music tempo preference. Initially, 128 undergraduate students (M age = 20.0 years, SD = 0.9) were surveyed to establish their three favorite music artists. A separate experimental group of 29 undergraduates (M age =…

  9. Heart Rate Variability Interventions for Concussion and Rehabilitation

    Directory of Open Access Journals (Sweden)

    Robert Lake Conder

    2014-08-01

    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.

  10. Gonadal hormones and heart rate as an emotional response

    NARCIS (Netherlands)

    de Loos, Wolter Statius

    1988-01-01

    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

  11. Monitoring of fetal heart rate and uterine activity

    NARCIS (Netherlands)

    Graatsma, E.M.

    2010-01-01

    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

  12. A healthy heart is not a metronome: an integrative review of the heart's anatomy and heart rate variability

    Science.gov (United States)

    Shaffer, Fred; McCraty, Rollin; Zerr, Christopher L.

    2014-01-01

    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. PMID:25324790

  13. [Design of a Front-end Device of Heart Rate Variability Analysis System Based on Photoplethysmography].

    Science.gov (United States)

    Shi, Lei; Sun, Peng; Pang, Yu; Luo, Zhiyong; Wang, Wei; Wang, Yanxiang

    2016-02-01

    Heart rate variability (HRV) is the difference between the successive changes in the heartbeat cycle, and it is produced in the autonomic nervous system modulation of the sinus node of the heart. The HRV is a valuable indicator in predicting the sudden cardiac death and arrhythmic events. Traditional analysis of HRV is based on a multielectrocardiogram (ECG), but the ECG signal acquisition is complex, so we have designed an HRV analysis system based on photoplethysmography (PPG). PPG signal is collected by a microcontroller from human's finger, and it is sent to the terminal via USB-Serial module. The terminal software not only collects the data and plot waveforms, but also stores the data for future HRV analysis. The system is small in size, low in power consumption, and easy for operation. It is suitable for daily care no matter whether it is used at home or in a hospital.

  14. Heart rate variability in neonates of type 1 diabetic pregnancy.

    Science.gov (United States)

    Russell, Noirin E; Higgins, Mary F; Kinsley, Brendan F; Foley, Michael E; McAuliffe, Fionnuala M

    2016-01-01

    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.

  15. Heart rate variability in infants with West syndrome

    DEFF Research Database (Denmark)

    Møller, Michelle Mai; Høgenhaven, Hans; Uldall, Peter

    2015-01-01

    with WS the heart rate variability (HRV) was investigated by examining time- and frequency-domain parameters of HRV at the time of the diagnosis of hypsarrhythmia and compared to 22 age-matched controls. For the WS patients the same dataset was obtained and compared again at the end of the study period......PURPOSE: West syndrome (WS) is a severe age-related acute epileptic encephalopathy of infancy characterized by infantile spasms, hypsarrhythmia and psychomotor delay. The aim of this study was to investigate if patients with WS had an altered autonomic output to the heart. METHODS: In 23 patients......-Whitney's U-Test) in the awake state, indicating an abnormal autonomic output to the heart. Comparing the initial to the final examination demonstrated a significant increase in the HRV parameters SDNN (31.3ms) and total power (757ms(2); p=0.001 and p=0.013, Wilcoxon Signed Ranked Test). In addition...

  16. Diminution of Heart Rate Variability in Bipolar Depression

    Directory of Open Access Journals (Sweden)

    Brandon Hage

    2017-12-01

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

  17. Ambulatory heart rate range predicts mode-specific mortality and hospitalisation in chronic heart failure.

    Science.gov (United States)

    Cubbon, Richard M; Ruff, Naomi; Groves, David; Eleuteri, Antonio; Denby, Christine; Kearney, Lorraine; Ali, Noman; Walker, Andrew M N; Jamil, Haqeel; Gierula, John; Gale, Chris P; Batin, Phillip D; Nolan, James; Shah, Ajay M; Fox, Keith A A; Sapsford, Robert J; Witte, Klaus K; Kearney, Mark T

    2016-02-01

    We aimed to define the prognostic value of the heart rate range during a 24 h period in patients with chronic heart failure (CHF). Prospective observational cohort study of 791 patients with CHF associated with left ventricular systolic dysfunction. Mode-specific mortality and hospitalisation were linked with ambulatory heart rate range (AHRR; calculated as maximum minus minimum heart rate using 24 h Holter monitor data, including paced and non-sinus complexes) in univariate and multivariate analyses. Findings were then corroborated in a validation cohort of 408 patients with CHF with preserved or reduced left ventricular ejection fraction. After a mean 4.1 years of follow-up, increasing AHRR was associated with reduced risk of all-cause, sudden, non-cardiovascular and progressive heart failure death in univariate analyses. After accounting for characteristics that differed between groups above and below median AHRR using multivariate analysis, AHRR remained strongly associated with all-cause mortality (HR 0.991/bpm increase in AHRR (95% CI 0.999 to 0.982); p=0.046). AHRR was not associated with the risk of any non-elective hospitalisation, but was associated with heart-failure-related hospitalisation. AHRR was modestly associated with the SD of normal-to-normal beats (R(2)=0.2; pheart rate (R(2)=0.33; p<0.001). Analysis of the validation cohort revealed AHRR to be associated with all-cause and mode-specific death as described in the derivation cohort. AHRR is a novel and readily available prognosticator in patients with CHF, which may reflect autonomic tone and exercise capacity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  18. Arterial wall mechanics as a function of heart rate: role of vascular smooth muscle

    International Nuclear Information System (INIS)

    Salvucci, Fernando Pablo; Schiavone, Jonathan; Craiem, Damian; Barra, Juan Gabriel

    2007-01-01

    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

  19. Attenuated heart rate response is associated with hypocretin deficiency in patients with narcolepsy.

    Science.gov (United States)

    Sorensen, Gertrud Laura; Knudsen, Stine; Petersen, Eva Rosa; Kempfner, Jacob; Gammeltoft, Steen; Sorensen, Helge Bjarup Dissing; Jennum, Poul

    2013-01-01

    Several studies have suggested that hypocretin-1 may influence the cerebral control of the cardiovascular system. We analyzed whether hypocretin-1 deficiency in narcolepsy patients may result in a reduced heart rate response. We analyzed the heart rate response during various sleep stages from a 1-night polysomnography in patients with narcolepsy and healthy controls. The narcolepsy group was subdivided by the presence of +/- cataplexy and +/- hypocretin-1 deficiency. Sleep laboratory studies conducted from 2001-2011. In total 67 narcolepsy patients and 22 control subjects were included in the study. Cataplexy was present in 46 patients and hypocretin-1 deficiency in 38 patients. None. All patients with narcolepsy had a significantly reduced heart rate response associated with arousals and leg movements (P hypocretin-1 deficiency and cataplexy groups compared with patients with normal hypocretin-1 levels (P hypocretin-1 deficiency significantly predicted the heart rate response associated with arousals in both REM and non-REM in a multivariate linear regression. Our results show that autonomic dysfunction is part of the narcoleptic phenotype, and that hypocretin-1 deficiency is the primary predictor of this dysfunction. This finding suggests that the hypocretin system participates in the modulation of cardiovascular function at rest.

  20. General anesthesia suppresses normal heart rate variability in humans

    Science.gov (United States)

    Matchett, Gerald; Wood, Philip

    2014-06-01

    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.

  1. Cardiolipin modulates allosterically peroxynitrite detoxification by horse heart cytochrome c

    Energy Technology Data Exchange (ETDEWEB)

    Ascenzi, Paolo, E-mail: ascenzi@uniroma3.it [Department of Biology and Interdepartmental Laboratory for Electron Microscopy, University Roma Tre, I-00146 Roma (Italy); Ciaccio, Chiara [Department of Experimental Medicine and Biochemical Sciences, University of Roma ' Tor Vergata' , I-00133 Roma (Italy); Interuniversity Consortium for the Research on the Chemistry of Metals in Biological Systems, I-70126 Bari (Italy); Sinibaldi, Federica; Santucci, Roberto [Department of Experimental Medicine and Biochemical Sciences, University of Roma ' Tor Vergata' , I-00133 Roma (Italy); Coletta, Massimo [Department of Experimental Medicine and Biochemical Sciences, University of Roma ' Tor Vergata' , I-00133 Roma (Italy); Interuniversity Consortium for the Research on the Chemistry of Metals in Biological Systems, I-70126 Bari (Italy)

    2011-01-07

    Research highlights: {yields} Cardiolipin binding to cytochrome c. {yields} Cardiolipin-dependent peroxynitrite isomerization by cytochrome c. {yields} Cardiolipin-cytochrome c complex plays pro-apoptotic effects. {yields} Cardiolipin-cytochrome c complex plays anti-apoptotic effects. -- Abstract: Upon interaction with bovine heart cardiolipin (CL), horse heart cytochrome c (cytc) changes its tertiary structure disrupting the heme-Fe-Met80 distal bond, reduces drastically the midpoint potential out of the range required for its physiological role, binds CO and NO with high affinity, and displays peroxidase activity. Here, the effect of CL on peroxynitrite isomerization by ferric cytc (cytc-Fe(III)) is reported. In the absence of CL, hexa-coordinated cytc does not catalyze peroxynitrite isomerization. In contrast, CL facilitates cytc-Fe(III)-mediated isomerization of peroxynitrite in a dose-dependent fashion inducing the penta-coordination of the heme-Fe(III)-atom. The value of the second order rate constant for CL-cytc-Fe(III)-mediated isomerization of peroxynitrite (k{sub on}) is (3.2 {+-} 0.4) x 10{sup 5} M{sup -1} s{sup -1}. The apparent dissociation equilibrium constant for CL binding to cytc-Fe(III) is (5.1 {+-} 0.8) x 10{sup -5} M. These results suggest that CL-cytc could play either pro-apoptotic or anti-apoptotic effects facilitating lipid peroxidation and scavenging of reactive nitrogen species, such as peroxynitrite, respectively.

  2. Sensitivity, Specificity and Predictive Value of Heart Rate Variability Indices in Type 1 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Anne Kastelianne França da Silva

    Full Text Available Abstract Background: Heart rate variability (HRV indices may detect autonomic changes with good diagnostic accuracy. Type diabetes mellitus (DM individuals may have changes in autonomic modulation; however, studies of this nature in this population are still scarce. Objective: To compare HRV indices between and assess their prognostic value by measurements of sensitivity, specificity and predictive values in young individuals with type 1 DM and healthy volunteers. Methods: In this cross-sectional study, physical and clinical assessment was performed in 39 young patients with type 1 DM and 43 young healthy controls. For HRV analysis, beat-to-beat heart rate variability was measured in dorsal decubitus, using a Polar S810i heart rate monitor, for 30 minutes. The following indices were calculated: SDNN, RMSSD, PNN50, TINN, RRTri, LF ms2, HF ms2, LF un, HF un, LF/HF, SD1, SD2, SD1/SD2, and ApEn. Results: Type 1 DM subjects showed a decrease in sympathetic and parasympathetic activities, and overall variability of autonomic nervous system. The RMSSD, SDNN, PNN50, LF ms2, HF ms2, RRTri, SD1 and SD2 indices showed greater diagnostic accuracy in discriminating diabetic from healthy individuals. Conclusion: Type 1 DM individuals have changes in autonomic modulation. The SDNN, RMSSD, PNN50, RRtri, LF ms2, HF ms2, SD1 and SD2 indices may be alternative tools to discriminate individuals with type 1 DM.

  3. Portable Heart Rate Detector Based on Photoplethysmography with Android Programmable Devices for Ubiquitous Health Monitoring System

    Directory of Open Access Journals (Sweden)

    Chi Kin Lao

    2013-01-01

    Full Text Available In this paper, a miniature portable heart rate detector system is implemented by modern hardware ICs and simple sensor circuit with software executable on both PC and Android platform. The biosignal is first extracted via photoplethysmography (PPG principle into electric signal. Then a microprocessor is used to covert biosignal from analog to digital format, suitably for feeding into an RF module (nRF24L01 for RF transmission. On the receiver end, the computer and/or smart phone can analyze the data using a robust algorithm that can detect peaks of the PPG waveform, hence to calculating the heart rate. Some application software running on Windows and Android phone have been developed to display heart rate information and time domain waveform to users for health care monitoring. In the future, pure Bluetooth technology will be used for wireless personal communications instead of RF modules. At the same time, the data can be sent to computer console using existing available networks (3G, 4G, WiFi, etc. for health database logging purpose.

  4. Predictive value of casual ECG-based resting heart rate compared with resting heart rate obtained from Holter recording

    DEFF Research Database (Denmark)

    Carlson, Nicholas; Dixen, Ulrik; Marott, Jacob L

    2014-01-01

    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...... and mean HR by Multivariate Cox regression was performed. RESULTS: A total of 57 composite endpoints occurred during 17.1 years of follow-up. Regression analysis suggests correlation between Casual RHR and Holter RHR. Multivariate Cox regression analysis adjusted for gender and age demonstrated hazard...... rates of 1.02 (p = 0.079) for casual RHR, 1.04 (p = 0.036*) for Holter RHR, and 1.03 (p = 0.093) for mean HR for each 10 beat increment in HR. CONCLUSIONS: In a comparative analysis on the correlation and significance of differing RHR measurement modalities RHR measured by 24-hour Holter recording...

  5. Qigong Effects on Heart Rate Variability and Peripheral Vasomotor Responses.

    Science.gov (United States)

    Chang, Mei-Ying

    2015-11-01

    Population aging is occurring worldwide, and preventing cardiovascular event in older people is a unique challenge. The aim of this study was to examine the effects of a 12-week qigong (eight-form moving meditation) training program on the heart rate variability and peripheral vasomotor response of middle-aged and elderly people in the community. This was a quasi-experimental study that included the pre-test, post-test, and nonequivalent control group designs. Seventy-seven participants (experimental group = 47; control group = 30) were recruited. The experimental group performed 30 min of eight-form moving meditation 3 times per week for 12 weeks, and the control group continued their normal daily activities. After 12 weeks, the interaction effects indicated that compared with the control group, the experimental group exhibited significantly improved heart rate variability and peripheral vasomotor responses. © The Author(s) 2014.

  6. Heart Rate Variability: Why Chaos can be healthy

    Directory of Open Access Journals (Sweden)

    Jorge Cancino

    2011-12-01

    Full Text Available Body autonomic interactions, mediated by sympathetic-parasympathetic balance, have been widely associated with stress and internal homeostasis. The acquisition of data, otherwise hidden in the signal from RR interval duration in heart rate, has given scientists access to the quantification of autonomic balance in humans, as long as the appropriate mathematical analyses are performed. With this information it is possible to know and understand the chaotic behavior of RR signals; this behavior shows the existence of heart rate variability (HRV. Variability is lost in some conditions associated with the presence of pathologies. In addition, with exercise being a stress agent, HRV analysis has been used as a tool to study training load assimilation and overtraining syndrome.

  7. Heart rate variability reactivity and new romance: Cause or consequence?

    Science.gov (United States)

    Bailey, Laura K; Davis, Ron

    2017-09-01

    There are documented physiological differences between single and coupled individuals during the "honeymoon period" of nascent romantic relationships. One such difference is in autonomic reactivity, specifically heart rate variability (HRV) reactivity. This finding had previously been interpreted as evidence of a stress buffering effect of relationship formation. The present study explored among university women two competing longitudinal hypotheses conceptualizing differences in HRV reactivity as either a cause or a consequence of romantic relationship formation. Results did not support the hypothesis that HRV reactivity changes as a consequence of beginning a new romantic relationship. Instead, lower HRV reactivity predicted greater relationship formation amongst women with low BMI and higher resting HRV. The functioning of the heart therefore predicted the likelihood that an individual would find love. These interactions may be the result of differing success rates of various mating strategies for women with low and high BMI and HRV. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Effect of Smoking on Blood Pressure and Resting Heart Rate

    DEFF Research Database (Denmark)

    Linneberg, Allan; Jacobsen, Rikke K; Skaaby, Tea

    2015-01-01

    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...... for smoking heaviness in current smokers. In observational analyses, current as compared with never smoking was associated with lower SBP, DBP, and lower hypertension risk, but with higher resting heart rate. In observational analyses amongst current smokers, one cigarette/day higher level of smoking...

  9. [Heart rate variability during sleep in children with multiple disabilities].

    Science.gov (United States)

    Bouquier, L; Amand, M; Van Eecke, D

    2013-12-01

    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.

  10. Assessing Metabolic Syndrome Through Increased Heart Rate During Exercise

    Directory of Open Access Journals (Sweden)

    Masoumeh Sadeghi

    2016-12-01

    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.

  11. Heart rate variability related to effort at work.

    Science.gov (United States)

    Uusitalo, Arja; Mets, Terhi; Martinmäki, Kaisu; Mauno, Saija; Kinnunen, Ulla; Rusko, Heikki

    2011-11-01

    Changes in autonomic nervous system function have been related to work stress induced increases in cardiovascular morbidity and mortality. Our purpose was to examine whether various heart rate variability (HRV) measures and new HRV-based relaxation measures are related to self-reported chronic work stress and daily emotions. The relaxation measures are based on neural network modelling of individual baseline heart rate and HRV information. Nineteen healthy hospital workers were studied during two work days during the same work period. Daytime, work time and night time heart rate, as well as physical activity were recorded. An effort-reward imbalance (ERI) questionnaire was used to assess chronic work stress. The emotions of stress, irritation and satisfaction were assessed six times during both days. Seventeen subjects had an ERI ratio over 1, indicating imbalance between effort and reward, that is, chronic work stress. Of the daily emotions, satisfaction was the predominant emotion. The daytime relaxation percentage was higher on Day 2 than on Day 1 (4 ± 6% vs. 2 ± 3%, p work time relaxation on the both Days. Chronic work stress correlated with the vagal activity index of HRV. However, effort at work had many HRV correlates: the higher the work effort the lower daytime HRV and relaxation time. Emotions at work were also correlated with work time (stress and satisfaction) and night time (irritation) HRV. These results indicate that daily emotions at work and chronic work stress, especially effort, is associated with cardiac autonomic function. Neural network modelling of individual heart rate and HRV information may provide additional information in stress research in field conditions. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  12. Effects of intranasal kinetic oscillation stimulation on heart rate variability.

    Science.gov (United States)

    Jerling, Markus; Cygankiewicz, Iwona; Al-Tawil, Nabil; Darpo, Borje; Ljungström, Anders; Zareba, Wojciech

    2018-01-01

    Kinetic oscillation stimulation in the nasal cavity (KOS) has been shown to have positive symptomatic effects in subjects with non-allergic rhinitis and in patients with migraine. To evaluate the effect of KOS on autonomic function, we assessed heart rate variability (HRV) in this small exploratory study in 12 healthy subjects. KOS treatment was performed using a minimally invasive system with a single-use catheter inserted into the nasal cavity. During treatment, the tip was inflated and oscillated with a mean pressure of 95 millibar and amplitude of the oscillations of 100 millibar at a frequency of 68 Hz. Treatment was given for 15 minutes sequentially on each side. Heart rate variability was assessed during five 30-minutes periods before, during and immediately after KOS treatment and 3.5 hours thereafter. KOS resulted in a substantial reduction of HRV. As compared to baseline recorded during 30 minutes preceding treatment, VLF was reduced by 65%, LF by 55%, the ratio LF/HF by 44%, with somewhat smaller observed effects in the time domain; SDNN and RMSDD were reduced by of 36% and 18%, respectively. Heart rate remained stable during treatment with minimal mean changes from 68 ± 7 bpm before to 68 ± 9 and 69 ± 9 bpm during and after treatment. Reduction of HRV parameters was consistently seen in all subjects, with rapid onset and return towards baseline values during post-treatment observation periods. KOS has an effect on the autonomic balance with pronounced heart-rate independent reduction on HRV. © 2017 The Authors Annals of Noninvasive Electrocardiology Published by Wiley Periodicals, Inc.

  13. Association of heart rate profile during exercise with the severity of coronary artery disease.

    Science.gov (United States)

    Cay, Serkan; Ozturk, Sezgin; Biyikoglu, Funda; Yildiz, Abdulkadir; Cimen, Tolga; Uygur, Belma; Tuna, Funda

    2009-05-01

    Coronary artery disease is the leading cause of morbidity and mortality around the world. Autonomic nervous system abnormalities are associated with coronary artery disease and its complications. Exercise stress tests are routinely used for the detection of the presence of coronary artery disease. In this study, we observed the association between heart rate profile during exercise and the severity of coronary artery disease. One hundred and sixty patients with abnormal exercise treadmill test (> or =1 mm horizontal or downsloping ST-segment depression; 119 men, 41 women; mean age = 57 +/- 9 years) were included in the study. Use of any drug affecting heart rate was not permitted. Resting heart rate before exercise, maximum heart rate during exercise, and resting heart rate after exercise (5 min later) were measured and two parameters were calculated: heart rate increment (maximum heart rate - resting heart rate before exercise) and heart rate decrement (maximum heart rate - resting heart rate after exercise). All patients underwent selective coronary angiography and subclassified into two groups according to stenotic lesion severity. Group 1 had at least 50% of stenotic lesion and group 2 had less than 50%. Patients in the first group had increased resting heart rate, decreased maximum heart rate, decreased heart rate increment, and decreased heart rate decrement compared with second group. All patients were classified into tertiles of resting heart rate, heart rate increment, and heart rate decrement level to evaluate whether these parameters were associated with severity of coronary artery stenosis in the study. The multiple-adjusted odds ratio of the risk of severe coronary atherosclerosis was 21.888 (95% confidence interval 6.983-68.606) for the highest tertile of resting heart rate level compared with the lowest tertile. In addition, the multiple-adjusted odds ratio of the risk of severe coronary atherosclerosis was 20.987 (95% confidence interval 6

  14. Quantification of Feto-Maternal Heart Rate from Abdominal ECG Signal Using Empirical Mode Decomposition for Heart Rate Variability Analysis

    Directory of Open Access Journals (Sweden)

    Abdullah Bin Queyam

    2017-10-01

    Full Text Available In this paper, a robust method of feto-maternal heart rate extraction from the non-invasive composite abdominal Electrocardiogram (aECG signal is presented. The proposed method is based on the Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN method, in which a composite aECG signal is decomposed into its constituent frequency components called Intrinsic Mode Functions (IMFs or simply “modes”, with better spectral separation. Decomposed IMFs are then selected manually according to probable maternal and fetal heart rate information and are processed further for quantification of maternal and fetal heart rate and variability analysis. The proposed method was applied to aECG recordings collected from three different sources: (i the PhysioNet (adfecgdb database; (ii the PhysioNet (nifecgdb database; and (iii synthetic aECG signal generated from mathematical modeling in the LabVIEW software environment. An overall sensitivity of 98.83%, positive diagnostic value of 97.97%, accuracy of 96.93% and performance index of 96.75% were obtained in the case of Maternal Heart Rate (MHR quantification, and an overall sensitivity of 98.13%, positive diagnostic value of 97.62%, accuracy of 95.91% and performance index of 95.69% were obtained in case of Fetal Heart Rate (FHR quantification. The obtained results confirm that CEEMDAN is a very robust and accurate method for extraction of feto-maternal heart rate components from aECG signals. We also conclude that non-invasive aECG is an effective and reliable method for long-term FHR and MHR monitoring during pregnancy and labor. The requirement of manual intervention while selecting the probable maternal and fetal components from “n” number of decomposed modes limits the real-time application of the proposed methodology. This is due to the fact that the number of modes “n” produced by the CEEMDAN decomposition is unpredictable. However, the proposed methodology is well suited

  15. Local dynamics of heart rate: detection and prognostic implications

    International Nuclear Information System (INIS)

    Moss, Travis J; Lake, Douglas E; Moorman, J Randall

    2014-01-01

    The original observation that reduced heart rate variability (HRV) confers poor prognosis after myocardial infarction has been followed by many studies of heart rate dynamics. We tested the hypothesis that an entropy-based local dynamics measure gave prognostic information in ambulatory patients undergoing 24-h electrocardiography. In this context, entropy is the probability that short templates will find matches in the time series. We studied RR interval time series from 24-h Holter monitors of 1564 consecutive patients over age 39. We generated histograms of the count of templates as a function of the number of templates matches in short RR interval time series, and found characteristic appearance of histograms for atrial fibrillation, sinus rhythm with normal HRV, and sinus rhythm with reduced HRV and premature ventricular contractions (PVCs). We developed statistical models to detect the abnormal dynamic phenotype of reduced HRV with PVCs and fashioned a local dynamics score (LDs) that, after controlling for age, added more prognostic information than other standard risk factors and common HRV metrics, including, to our surprise, the PVC count and the HRV of normal-to-normal intervals. Addition of the LDs to a predictive model using standard risk factors significantly increased the ROC area and the net reclassification improvement was 27%. We conclude that abnormal local dynamics of heart rate confer adverse prognosis in patients undergoing 24-h ambulatory electrocardiography. (paper)

  16. Modeling heart rate variability including the effect of sleep stages

    Science.gov (United States)

    Soliński, Mateusz; Gierałtowski, Jan; Żebrowski, Jan

    2016-02-01

    We propose a model for heart rate variability (HRV) of a healthy individual during sleep with the assumption that the heart rate variability is predominantly a random process. Autonomic nervous system activity has different properties during different sleep stages, and this affects many physiological systems including the cardiovascular system. Different properties of HRV can be observed during each particular sleep stage. We believe that taking into account the sleep architecture is crucial for modeling the human nighttime HRV. The stochastic model of HRV introduced by Kantelhardt et al. was used as the initial starting point. We studied the statistical properties of sleep in healthy adults, analyzing 30 polysomnographic recordings, which provided realistic information about sleep architecture. Next, we generated synthetic hypnograms and included them in the modeling of nighttime RR interval series. The results of standard HRV linear analysis and of nonlinear analysis (Shannon entropy, Poincaré plots, and multiscale multifractal analysis) show that—in comparison with real data—the HRV signals obtained from our model have very similar properties, in particular including the multifractal characteristics at different time scales. The model described in this paper is discussed in the context of normal sleep. However, its construction is such that it should allow to model heart rate variability in sleep disorders. This possibility is briefly discussed.

  17. Poincare indices for analyzing meditative heart rate signals

    Directory of Open Access Journals (Sweden)

    Atefeh Goshvarpour

    2015-06-01

    Full Text Available Background: Poincare plots are commonly used to study the nonlinear behavior of physiologic signals. The aim of this study is to evaluate the Poincare plot indices of human heart rate signals during meditation. Methods: For this purpose, heart rate time series of eight Chi meditators available in Physionet database were used. Poincare plots with lags of 1 and 6 were constructed, and the ratio of the minor axis to major axis (SD1/SD2 and the area of Poincare plots were calculated for each lag. Results: The results show that the SD1/SD2 ratio increased significantly during meditation compared to that before meditation, especially the index measured from Poincare plots reconstructed with a lag of 6 (p < 0.05. In addition, in both lags, the area of Poincare plots decreased significantly during meditation compared to before meditation (p < 0.05. Conclusion: The comparative dynamic measures of the Poincare plot indices during and before meditation give more insight of the heart rate signals in a specific psychophysiological state.

  18. Effects of Stretching Exercise on Heart Rate Variability During Pregnancy.

    Science.gov (United States)

    Logan, Jeongok G; Yeo, SeonAe

    Little evidence exists for effects of low-intensity exercises such as stretching on cardiovascular health in pregnant women. Our aim was to evaluate the effect of a 20-minute stretching exercise on heart rate variability (HRV), blood pressure (BP), and heart rate (HR) in healthy pregnant women. In 15 pregnant women with a mean (SD) age of 29.47 (4.07) years and mean (SD) gestational weeks of 26.53 (8.35), HRV, and BP were measured before and after the 20-minute stretching exercise. Compared with before the stretching exercise, standard deviation of the normal-to-normal intervals, total variability of heart rate, increased by 7.40 milliseconds (t = -2.31, P = .04) and root mean square of successive differences, a surrogate measure of parasympathetic outflow, also increased by 11.68 milliseconds (Z = -2.04, P = .04) after the stretching exercise. Diastolic BP and HR decreased by 2.13 mm Hg (t = 1.93, P = .07) and 3.31 bpm (t = 2.17, P = .05), respectively, but they did not reach statistical significance. These preliminary data suggest that 20 minutes of stretching exercise may promote cardiovascular health by attenuating the loss of parasympathetic tone associated with pregnancy.

  19. Classifying work rate from heart rate measurements using an adaptive neuro-fuzzy inference system.

    Science.gov (United States)

    Kolus, Ahmet; Imbeau, Daniel; Dubé, Philippe-Antoine; Dubeau, Denise

    2016-05-01

    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.

  20. Nonlinear Methods to Assess Changes in Heart Rate Variability in Type 2 Diabetic Patients

    International Nuclear Information System (INIS)

    Bhaskar, Roy; Ghatak, Sobhendu

    2013-01-01

    Heart rate variability (HRV) is an important indicator of autonomic modulation of cardiovascular function. Diabetes can alter cardiac autonomic modulation by damaging afferent inputs, thereby increasing the risk of cardiovascular disease. We applied nonlinear analytical methods to identify parameters associated with HRV that are indicative of changes in autonomic modulation of heart function in diabetic patients. We analyzed differences in HRV patterns between diabetic and age-matched healthy control subjects using nonlinear methods. Lagged Poincaré plot, autocorrelation, and detrended fluctuation analysis were applied to analyze HRV in electrocardiography (ECG) recordings. Lagged Poincare plot analysis revealed significant changes in some parameters, suggestive of decreased parasympathetic modulation. The detrended fluctuation exponent derived from long-term fitting was higher than the short-term one in the diabetic population, which was also consistent with decreased parasympathetic input. The autocorrelation function of the deviation of inter-beat intervals exhibited a highly correlated pattern in the diabetic group compared with the control group. The HRV pattern significantly differs between diabetic patients and healthy subjects. All three statistical methods employed in the study may prove useful to detect the onset and extent of autonomic neuropathy in diabetic patients

  1. Nonlinear Methods to Assess Changes in Heart Rate Variability in Type 2 Diabetic Patients

    Energy Technology Data Exchange (ETDEWEB)

    Bhaskar, Roy, E-mail: imbhaskarall@gmail.com [Indian Institute of Technology (India); University of Connecticut, Farmington, CT (United States); Ghatak, Sobhendu [Indian Institute of Technology (India)

    2013-10-15

    Heart rate variability (HRV) is an important indicator of autonomic modulation of cardiovascular function. Diabetes can alter cardiac autonomic modulation by damaging afferent inputs, thereby increasing the risk of cardiovascular disease. We applied nonlinear analytical methods to identify parameters associated with HRV that are indicative of changes in autonomic modulation of heart function in diabetic patients. We analyzed differences in HRV patterns between diabetic and age-matched healthy control subjects using nonlinear methods. Lagged Poincaré plot, autocorrelation, and detrended fluctuation analysis were applied to analyze HRV in electrocardiography (ECG) recordings. Lagged Poincare plot analysis revealed significant changes in some parameters, suggestive of decreased parasympathetic modulation. The detrended fluctuation exponent derived from long-term fitting was higher than the short-term one in the diabetic population, which was also consistent with decreased parasympathetic input. The autocorrelation function of the deviation of inter-beat intervals exhibited a highly correlated pattern in the diabetic group compared with the control group. The HRV pattern significantly differs between diabetic patients and healthy subjects. All three statistical methods employed in the study may prove useful to detect the onset and extent of autonomic neuropathy in diabetic patients.

  2. Bluetooth(Registered Trademark) Heart Rate Monitors for Spaceflight

    Science.gov (United States)

    Buxton, Roxanne E.; West, Michael R.; Kalogera, Kent L.; Hanson, Andrea M.

    2016-01-01

    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

  3. Relationship between exercise heart rate and music tempo preference

    OpenAIRE

    Karageorghis, CI; Jones, L; Low, DC

    2006-01-01

    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. ...

  4. Heart rate turbulence and variability in patients with ventricular arrhythmias

    Directory of Open Access Journals (Sweden)

    Diego Tarricone

    2009-08-01

    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

  5. Effects of Posteroanterior Thoracic Mobilization on Heart Rate Variability and Pain in Women with Fibromyalgia

    Directory of Open Access Journals (Sweden)

    Michel Silva Reis

    2014-01-01

    Full Text Available Fibromyalgia (FM has been associated with cardiac autonomic abnormalities and pain. Heart rate variability (HRV is reduced in FM with autonomic tone dominated by sympathetic activity. The purpose of this study was to evaluate the effects of one session of a posteroanterior glide technique on both autonomic modulation and pain in woman with FM. This was a controlled trial with immediate followup; twenty premenopausal women were allocated into 2 groups: (i women diagnosed with FM (n=10 and (ii healthy women (n=10. Both groups received one session of Maitland mobilization grade III posteroanterior central pressure glide, at 2 Hz for 60 s at each vertebral segment. Autonomic modulation was assessed by HRV and pain by a numeric pain scale before and after the intervention. For HRV analyses, heart rate and RR intervals were recorded for 10 minutes. FM subjects demonstrated reduced HRV compared to controls. Although the mobilization technique did not significantly reduce pain, it was able to improve HRV quantified by an increase in rMSSD and SD1 indices, reflecting an improved autonomic profile through increased vagal activity. In conclusion, women with FM presented with impaired cardiac autonomic modulation. One session of Maitland spine mobilization was able to acutely improve HRV.

  6. Effects of GABA, Neural Regulation, and Intrinsic Cardiac Factors on Heart Rate Variability in Zebrafish Larvae.

    Science.gov (United States)

    Vargas, Rafael Antonio

    2017-04-01

    Heart rate (HR) is a periodic activity that is variable over time due to intrinsic cardiac factors and extrinsic neural control, largely by the autonomic nervous system. Heart rate variability (HRV) is analyzed by measuring consecutive beat-to-beat intervals. This variability can contain information about the factors regulating cardiac activity under normal and pathological conditions, but the information obtained from such analyses is not yet fully understood. In this article, HRV in zebrafish larvae was evaluated under normal conditions and under the effect of substances that modify intrinsic cardiac activity and cardiac activity modulated by the nervous system. We found that the factors affecting intrinsic activity have negative chronotropic and arrhythmogenic effects at this stage of development, whereas neural modulatory factors have a lesser impact. The results suggest that cardiac activity largely depends on the intrinsic properties of the heart tissue in the early stages of development and, to a lesser extent, in the maturing nervous system. We also report, for the first time, the influence of the neurotransmitter gamma amino butyric acid on HRV. The results demonstrate the larval zebrafish model as a useful tool in the study of intrinsic cardiac activity and its role in heart diseases.

  7. Intracardiac Origin of Heart Rate Variability, Pacemaker Funny Current and their Possible Association with Critical Illness

    Science.gov (United States)

    Papaioannou, Vasilios E; Verkerk, Arie O; Amin, Ahmed S; de Bakker, Jaques MT

    2013-01-01

    Heart rate variability (HRV) is an indirect estimator of autonomic modulation of heart rate and is considered a risk marker in critical illness, particularly in heart failure and severe sepsis. A reduced HRV has been found in critically ill patients and has been associated with neuro-autonomic uncoupling or decreased baroreflex sensitivity. However, results from human and animal experimental studies indicate that intracardiac mechanisms might also be responsible for interbeat fluctuations. These studies have demonstrated that different membrane channel proteins and especially the so-called ‘funny’ current (If), an hyperpolarization-activated, inward current that drives diastolic depolarization resulting in spontaneous activity in cardiac pacemaker cells, are altered during critical illness. Furthermore, membrane channels kinetics seem to have significant impact upon HRV, whose early decrease might reflect a cellular metabolic stress. In this review article we present research findings regarding intracardiac origin of HRV, at the cellular level and in both isolated sinoatrial node and whole ex vivo heart preparations. In addition, we will review results from various experimental studies that support the interrelation between If and HRV during endotoxemia. We suggest that reduced HRV during sepsis could also be associated with altered pacemaker cell membrane properties, due to ionic current remodeling. PMID:22920474

  8. Loss of lag-response curvilinearity of indices of heart rate variability in congestive heart failure

    Directory of Open Access Journals (Sweden)

    Smith Michael L

    2006-06-01

    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.

  9. Heart rate responses to autonomic challenges in obstructive sleep apnea.

    Directory of Open Access Journals (Sweden)

    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

  10. Cardio-pulmonary fitness test by ultra-short heart rate variability.

    Science.gov (United States)

    Aslani, Arsalan; Aslani, Amir; Kheirkhah, Jalal; Sobhani, Vahid

    2011-10-01

    It is known that exercise induces cardio-respiratory autonomic modulation. The aim of this study was to assess the cardio-pulmonary fitness by ultra-short heart rate variability. Study population was divided into 3 groups: Group-1 (n = 40) consisted of military sports man. Group-2 (n = 40) were healthy age-matched sedentary male subjects with normal body mass index [BMI = 19 - 25 kg/m(2)). Group-3 (n = 40) were healthy age-matched obese male subjects [BMI > 29 kg/m(2)). Standard deviation of normal-to-normal QRS intervals (SDNN) was recorded over 15 minutes. Bruce protocol treadmill test was used; and, maximum oxygen consumption (VO(2)max) was calculated. WHEN THE STUDY POPULATION WAS DIVIDED INTO QUARTILES OF SDNN (FIRST QUARTILE: 60 and 100 and 140 msec), progressive increase was found in VO(2)max; and, SDNN was significantly linked with estimated VO(2)max. In conclusion, the results of this study demonstrate that exercise training improves cardio-respiratory autonomic function (and increases heart rate variability). Improvement in cardio-respiratory autonomic function seems to translate into a lower rate of long term mortality. Ultra-short heart rate variability is a simple cardio-pulmonary fitness test which just requires 15 minutes, and involves no exercise such as in the treadmill or cycle test.

  11. Elevated resting heart rate in heart transplant recipients: innocent bystander or adverse prognostic indicator?

    Science.gov (United States)

    Wachter, S Blake; McCandless, Sean P; Gilbert, Edward M; Stoddard, Gregory J; Kfoury, Abdallah G; Reid, Bruce B; McKellar, Stephen H; Nativi-Nicolau, Jose; Saidi, Abdulfattah; Barney, Jacob; McCreath, Lauren; Koliopoulou, Antigone; Wright, Spencer E; Fang, James C; Stehlik, Josef; Selzman, Craig H; Drakos, Stavros G

    2015-09-01

    The elevated baseline heart rate (HR) of a heart transplant recipient has previously been considered inconsequential. However, we hypothesized that a resting HR above 100 beats per minute (bpm) may be associated with morbidity and mortality. The U.T.A.H. Cardiac Transplant Program studied patients who received a heart transplant between 2000 and 2011. Outpatient HR values for each patient were averaged during the first year post-transplant. The study cohort was divided into two groups: the tachycardic (TC) (HR > 100 bpm) and the non-TC group (HR ≤ 100 bpm) in which mortality, incidence of rejection, and cardiac allograft vasculopathy were compared. Three hundred and ten patients were included as follows: 73 in the TC and 237 in the non-TC group. The TC group had a higher risk of a 10-yr all-cause mortality (p = 0.004) and cardiovascular mortality (p = 0.044). After adjustment for donor and recipient characteristics in multivariable logistic regression analysis, the hazard ratio was 3.9, (p = 0.03, CI: 1.2-13.2) and 2.6 (p = 0.02, CI: 1.2-5.5) for cardiovascular mortality and all-cause mortality, respectively. Heart transplant recipients with elevated resting HR appear to have higher mortality than those with lower resting HR. Whether pharmacologically lowering the HR would result in better outcomes warrants further investigation. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Deposition rate in modulated radio-frequency silane plasmas

    NARCIS (Netherlands)

    A.C.W. Biebericher,; Bezemer, J.; W.F. van der Weg,; W. J. Goedheer,

    2000-01-01

    Plasma-enhanced chemical-vapor deposition of amorphous silicon by a square-wave amplitude-modulated radio-frequency excitation has been studied by optical emission spectroscopy and plasma modeling. By the modulation, the deposition rate is increased or reduced, depending on the plasma parameters.

  13. Persistent atrial fibrillation worsens heart rate variability, activity and heart rate, as shown by a continuous monitoring by implantable biventricular pacemakers in heart failure patients.

    Science.gov (United States)

    Puglisi, Andrea; Gasparini, Maurizio; Lunati, Maurizio; Sassara, Massimo; Padeletti, Luigi; Landolina, Maurizio; Botto, Giovanni Luca; Vincenti, Antonio; Bianchi, Stefano; Denaro, Alessandra; Grammatico, Andrea; Boriani, Giuseppe

    2008-07-01

    Atrial fibrillation (AF) induces loss of atrial contribution, heart rate irregularity, and fast ventricular rate. The objectives of the study were to accurately measure AF incidence and to investigate the mutual temporal patterns of AF and heart failure (HF) in patients indicated to cardiac resynchronization therapy. Four hundred ten consecutive patients (70% male, age 69 +/- 11) with advanced HF (NYHA = 3.0 +/- 0.6), low ejection fraction (EF = 27 +/- 9%), and ventricular conduction delay (QRS = 165 +/- 29 ms) received a biventricular pacemaker. Enrolled patients were divided into two groups: G1 = 249 patients with no AF history, G2 = 161 patients with history of paroxysmal/persistent AF. In a median follow-up of 13 months, AF episodes longer than 5 minutes occurred in 105 of 249 (42.2%) G1 patients and 76 of 161 (47.2%) G2 patients, while AF episodes longer than one day occurred in 14 of 249 (5.6%) G1 patients and in 36 of 161 (22.4%) G2 patients. Device diagnostics monitored daily values of patient activity, night heart rate (NHR), and heart rate variability (HRV). Comparing 30-day periods before AF onset and during persistent AF, significant (P R(2)= 0.73) with activity, with a significant lower activity associated with NHR >or= 88 bpm. AF is frequent in HF patients. Persistent AF is associated with statistically significant decrease in patient activity and HRV and NHR increase.

  14. Adaptive Mean and Trend Removal of Heart Rate Variability Using Kalman Filtering

    National Research Council Canada - National Science Library

    Schloegl, A

    2001-01-01

    Analysis of heart rate van ability requires the calculation of the mean heart rate, Adaptive methods are important for online and real-time parameter estimation, In this paper we demonstrate the use...

  15. Spectral analysis of heart rate variability during trigger point acupuncture.

    Science.gov (United States)

    Kitagawa, Yoji; Kimura, Kenichi; Yoshida, Sohei

    2014-06-01

    To clarify changes in the cardiovascular autonomic nervous system function due to trigger point acupuncture, we evaluated differences in responses between acupuncture at trigger points and those at other sites using spectral analysis of heart rate variability. Subjects were 35 healthy men. Before measurements began the subjects were assigned to a trigger point acupuncture or control group based on the presence/absence of referred pain on applying pressure to a taut band within the right tibialis anterior muscle. The measurements were conducted in a room with a temperature of 25°C, with subjects in a long sitting position after 10 min rest. Acupuncture needles were retained for 10 min at two sites on the right tibialis anterior muscle. ECG was performed simultaneously with measurements of blood pressure and the respiratory cycle. Based on the R-R interval on the ECG, frequency analysis was performed, low-frequency (LF) and high-frequency (HF) components were extracted and the ratio of LF to HF components (LF/HF) was evaluated. The trigger point acupuncture group showed a transient decrease in heart rate and an increase in the HF component but no significant changes in LF/HF. In the control group, no significant changes were observed in heart rate, the HF component or LF/HF. There were no consistent changes in systolic or diastolic blood pressure in either group. These data suggest that acupuncture stimulation of trigger points of the tibialis anterior muscle transiently increases parasympathetic nerve activity. 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.

  16. Heart rate and estimated energy expenditure during ballroom dancing.

    Science.gov (United States)

    Blanksby, B A; Reidy, P W

    1988-06-01

    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).

  17. Simulation of heart rate variability model in a network

    Science.gov (United States)

    Cascaval, Radu C.; D'Apice, Ciro; D'Arienzo, Maria Pia

    2017-07-01

    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.

  18. Heart rate variability biofeedback: How and why does it work?

    Directory of Open Access Journals (Sweden)

    Paul M Lehrer

    2014-07-01

    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.

  19. Improved detection of congestive heart failure via probabilistic symbolic pattern recognition and heart rate variability metrics.

    Science.gov (United States)

    Mahajan, Ruhi; Viangteeravat, Teeradache; Akbilgic, Oguz

    2017-12-01

    A timely diagnosis of congestive heart failure (CHF) is crucial to evade a life-threatening event. This paper presents a novel probabilistic symbol pattern recognition (PSPR) approach to detect CHF in subjects from their cardiac interbeat (R-R) intervals. PSPR discretizes each continuous R-R interval time series by mapping them onto an eight-symbol alphabet and then models the pattern transition behavior in the symbolic representation of the series. The PSPR-based analysis of the discretized series from 107 subjects (69 normal and 38 CHF subjects) yielded discernible features to distinguish normal subjects and subjects with CHF. In addition to PSPR features, we also extracted features using the time-domain heart rate variability measures such as average and standard deviation of R-R intervals. An ensemble of bagged decision trees was used to classify two groups resulting in a five-fold cross-validation accuracy, specificity, and sensitivity of 98.1%, 100%, and 94.7%, respectively. However, a 20% holdout validation yielded an accuracy, specificity, and sensitivity of 99.5%, 100%, and 98.57%, respectively. Results from this study suggest that features obtained with the combination of PSPR and long-term heart rate variability measures can be used in developing automated CHF diagnosis tools. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Effect of polypeptides from sea anemone Heteractis crispa on the rodent blood pressure, heart rate, and hemostasis.

    Science.gov (United States)

    Skobtsova, L A; Dyachenko, I A; Andreev, Ya A; Logashina, Yu A; Murashev, A N; Grishin, E V

    2016-09-01

    АРНС1-3 peptides, modulators of TRPV1 receptors, have been administered to SD rats to study their influence on the animal hemostatic system, heart rate, and blood pressure. None of АЗРС1-3 polypeptides have any effect on the hemostatic system. Both АРНС1 and АРНС2 polypeptides increased significantly the heart rate, but they did not affect blood pressure, which was probably caused by an ability of these polypeptides to modify animal thermoregulation.

  1. Heart rate variability under resting conditions in postmenopausal and young women

    Directory of Open Access Journals (Sweden)

    Ribeiro T.F.

    2001-01-01

    Full Text Available The aim of the present study was to compare the modulation of heart rate in a group of postmenopausal women to that of a group of young women under resting conditions on the basis of R-R interval variability. Ten healthy postmenopausal women (mean ± SD, 58.3 ± 6.8 years and 10 healthy young women (mean ± SD, 21.6 ± 0.82 years were submitted to a control resting electrocardiogram (ECG in the supine and sitting positions over a period of 6 min. The ECG was obtained from a one-channel heart monitor at the CM5 lead and processed and stored using an analog to digital converter connected to a microcomputer. R-R intervals were calculated on a beat-to-beat basis from the ECG recording in real time using a signal-processing software. Heart rate variability (HRV was expressed as standard deviation (RMSM and mean square root (RMSSD. In the supine position, the postmenopausal group showed significantly lower (P<0.05 median values of RMSM (34.9 and RMSSD (22.32 than the young group (RMSM: 62.11 and RMSSD: 49.1. The same occurred in the sitting position (RMSM: 33.0 and RMSSD: 18.9 compared to RMSM: 57.6 and RMSSD: 42.8 for the young group. These results indicate a decrease in parasympathetic modulation in postmenopausal women compared to young women which was possibly due both to the influence of age and hormonal factors. Thus, time domain HRV proved to be a noninvasive and sensitive method for the identification of changes in autonomic modulation of the sinus node in postmenopausal women.

  2. Musical Auditory Stimulation Influences Heart Rate Autonomic Responses to Endodontic Treatment

    Directory of Open Access Journals (Sweden)

    Milana Drumond Ramos Santana

    2017-01-01

    Full Text Available We aimed to evaluate the acute effect of musical auditory stimulation on heart rate autonomic regulation during endodontic treatment. The study included 50 subjects from either gender between 18 and 40 years old, diagnosed with irreversible pulpitis or pulp necrosis of the upper front teeth and endodontic treatment indication. HRV was recorded 10 minutes before (T1, during (T2, and immediately (T3 and T4 after endodontic treatment. The volunteers were randomly divided into two equal groups: exposed to music (during T2, T3, and T4 or not. We found no difference regarding salivary cortisol and anxiety score. In the group with musical stimulation heart rate decreased in T3 compared to T1 and mean RR interval increased in T2 and T3 compared to T1. SDNN and TINN indices decreased in T3 compared to T4, the RMSSD and SD1 increased in T4 compared to T1, the SD2 increased compared to T3, and LF (low frequency band increased in T4 compared to T1 and T3. In the control group, only RMSSD and SD1 increased in T3 compared to T1. Musical auditory stimulation enhanced heart rate autonomic modulation during endodontic treatment.

  3. Endogenous vasopressin and the central control of heart rate during dynamic exercise

    Directory of Open Access Journals (Sweden)

    L.C. Michelini

    1998-09-01

    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.

  4. Making the Most of the "Daphnia" Heart Rate Lab: Optimizing the Use of Ethanol, Nicotine & Caffeine

    Science.gov (United States)

    Corotto, Frank; Ceballos, Darrel; Lee, Adam; Vinson, Lindsey

    2010-01-01

    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…

  5. Approximate entropy and point correlation dimension of heart rate variability in healthy subjects

    DEFF Research Database (Denmark)

    Storella, R J; Wood, H W; Mills, K M

    1999-01-01

    The contribution of nonlinear dynamics to heart rate variability in healthy humans was examined using surrogate data analysis. Several measures of heart rate variability were used and compared. Heart rates were recorded for three hours and original data sets of 8192 R-R intervals created. For eac...

  6. Heart Rates of High School Physical Education Students during Team Sports, Individual Sports, and Fitness Activities

    Science.gov (United States)

    Laurson, Kelly R.; Brown, Dale D.; Cullen, Robert W.; Dennis, Karen K.

    2008-01-01

    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…

  7. Discovery of novel heart rate-associated loci using the Exome Chip

    NARCIS (Netherlands)

    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.

    2017-01-01

    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

  8. Discovery of novel heart rate-associated loci using the Exome Chip

    DEFF Research Database (Denmark)

    van den Berg, Marten E; Warren, Helen R; Cabrera, Claudia P

    2017-01-01

    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...

  9. Discovery of novel heart rate-associated loci using the Exome Chip

    NARCIS (Netherlands)

    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)

    2017-01-01

    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

  10. Cortisol Levels and Autonomic Control of Heart Rate in Healthy Subjects

    Directory of Open Access Journals (Sweden)

    Santana Milana Drumond Ramos

    2017-08-01

    Full Text Available Introduction: There is an increase in level of stress in the general population because of the social, personal and professional demands. Currently, there are only simple tools that can safely measure this stress such as levels of cortisol and heart rate variability (HRV. Objective: To analyze the relationship between salivary cortisol and the cardiac autonomic modulation. Methods: A total of fifty-one male and female subjects between 18 and 40 years old were evaluated. Saliva collection was achieved for the salivary cortisol dosage. The collection was performed through the SalivetteR tube. After this collection, the median cortisol levels (0.24 ug/dl were analyzed and the volunteers were divided into two groups: i cortisol below the mediane ii cortisol above the median. After this division, each group consisted of 25 volunteers and then was verified the following information: age, gender, weight, height, body mass index (BMI, blood pressure. Shortly thereafter was assessment of cardiac autonomic modulation por meio da HRV. The Polar RS800cx heart rate receiver was placed on the chest of the volunteers, in the vicinity of the distal third of the sternum. The volunteers were instructed to remain in rest with spontaneous breathing in dorsal position for 20 minutes. HRV analysis included geometric, time and frequency domain indices. Results: There were no statistical differences for the two groups regarding systolic and diastolic blood pressure, heart rate, RR intervals or linear and frequency indices for the volunteers. In addition, also there was no correlation the cortisol with the analyzed variables (SAP, p=0.460; DAP, p = 0.270; HR, p = 0.360; RR, p = 0.380; SDNN, p = 0.510; rMSSD, p = 0.660; pNN50, p = 0.820; RRtri, p = 0.170; TINN, p = 0.470; SD1, p = 0.650; SD2, p = 0.500; LF [ms2], p = 0.880; LF [nu], p = 0.970; HF [ms2], p = 0.870; HF [nu], p = 0.960; LF/HF, p = 0.380 Conclusion: Heart rate variability autonomic control was unchanged in

  11. Night heart rate variability during overtraining in male endurance athletes.

    Science.gov (United States)

    Bosquet, L; Papelier, Y; Léger, L; Legros, P

    2003-12-01

    The purpose of the study was to examine whether an unaccustomed increase in training volume would result in characteristics changes in heart rate variability (HRV), in order to determine if this marker can be used to diagnose overtraining. Nine experienced endurance athletes increased their usual amount of training by 100% within 4 weeks. Night ECG was recorded before (baseline) and after (OVER) this period of overload, and after 2 weeks of recovery (REC). We diagnosed overtraining in 6 subjects using both physiological and psychological criteria. No difference was noted in heart rate for night periods (56+/-12, 55+/-10 and 53+/-15 bpm, respectively; p>0.05). We found no significant changes of LF/HF (1.10+/-0.92, 0.96+/-0.57 and 0.59+/-0.43, respectively; p>0.05) or HF expressed in normalized units (54.81+/-20.12, 53.81+/-11.35 and 66.15+/-15.12%, respectively; p>0.05). In the conditions of the present study, HRV during sleep does not seem to be a valid marker of overtraining in male endurance athletes. Before concluding to the uselessness of this tool in the monitoring of the syndrome, longitudinal studies with elite or sub-elite athletes are needed to determine if spontaneously developed overtraining results in the same response.

  12. Changes in heart rate during third molar surgery.

    Science.gov (United States)

    Hollander, M H J; Schortinghuis, J; Vissink, A

    2016-12-01

    Anxiety is an undesirable psychological phenomenon. Patients are usually anxious when subjected to third molar surgery, but the pattern of anxiety is unknown. The aim of this study was to assess the intensity and course of anxiety during third molar surgery. This study included 48 consecutive patients (mean age 25±6 years) who had a third molar removed surgically under local anaesthesia. The heart rate was monitored continuously during treatment as a measure of anxiety. Preoperative anxiety was scored with the Modified Dental Anxiety Scale. Each patient's anxiety level was assessed when in the waiting room, sitting down in the dental chair, during the application of local anaesthesia, application of surgical drapes, time-out procedure, incision, alveolotomy, removal of the third molar, and suturing, and at the end of the procedure. The lowest heart rates were recorded in the waiting room, in the dental chair, during anaesthesia, when applying surgical drapes, during suturing, and at the end of the procedure. The highest values were obtained during the time-out procedure, incision, and alveolotomy (Pthird molar surgery, with the lowest levels of anxiety prior to surgery and directly postoperative and the highest during the time-out procedure and the actual surgery. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  13. TRPA1 mediates changes in heart rate variability and cardiac ...

    Science.gov (United States)

    Short-term exposure to ambient air pollution is linked with adverse cardiovascular effects. While previous research focused primarily on particulate matter-induced responses, gaseous air pollutants also contribute to cause short-term cardiovascular effects. Mechanisms underlying such effects have not been adequately described; however, the immediate nature of the response suggests involvement of irritant neural activation and downstream autonomic dysfunction. Thus, this study examines the role of TRPA1, an irritant sensory receptor found in the airways, in the cardiac response of mice to acrolein and ozone. Conscious unrestrained wild-type C57BL/6 (WT) and TRPA1 knockout (KO) mice implanted with radiotelemeters were exposed once to 3ppm acrolein, 0.3ppm ozone, or filtered air. Heart rate (HR) and electrocardiogram (ECG) were recorded continuously before, during and after exposure. Analysis of ECG morphology, incidence of arrhythmia and heart rate variability (HRV) were performed. Cardiac mechanical function was assessed using a Langendorff perfusion preparation 24h post-exposure. Acrolein exposure increased HRV independent of HR, as well as incidence of arrhythmia. Acrolein also increased left ventricular developed pressure in WT mice at 24h post-exposure. Ozone did not produce any changes in cardiac function. Neither gas produced ECG effects, changes in HRV, arrhythmogenesis, or mechanical function in KO mice. These data demonstrate that a single exposure to ac

  14. Human heart rate variability relation is unchanged during motion sickness

    Science.gov (United States)

    Mullen, T. J.; Berger, R. D.; Oman, C. M.; Cohen, R. J.

    1998-01-01

    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.

  15. HEART RATE AND MOTION ANALYSIS BY GPS IN BEACH SOCCER

    Directory of Open Access Journals (Sweden)

    Julen Castellano

    2010-03-01

    Full Text Available Although beach soccer has become increasingly popular in recent years very little scientific research has been conducted into the sport. A pilot study was carried out with the aim of examining the physiological (heart rate and physical (motion analysis responses of beach soccer players during competitive matches. Ten players (age 25.5 ± 0.5 years; height 1.80 ± 0.08 m; weight 78.2 ± 5.6 kg. were studied over five beach soccer matches. The physiological demands were analysed by measuring heart rate (HR using telemetric devices, while the physical profile was evaluated by recording motion and speed by means of GPS devices. During competitive matches, players obtained a HRmean of 165.2 bpm (86.5% HRmax, with 59.3% of the time participating (TP corresponding to values above 90% of the HRmax. The distance covered per minute of participation was 97.7 m, with 9.5% of this distance corresponding to high-intensity running and 2.5% to sprint; the work:rest ratio was 1.4:1 and the maximum speed 21.7 km·h-1. These results showed that beach soccer is an intermittent physical activity of greater intensity than other team games. It requires a major contribution from the anaerobic system as emphasis is placed on players making quick bursts of high-intensity activity separated by brief rest periods

  16. Changes of deceleration and acceleration capacity of heart rate in patients with acute hemispheric ischemic stroke

    Directory of Open Access Journals (Sweden)

    Xu YH

    2016-03-01

    were negatively correlated with NIHSS scores (r=-0.279, r=-0.266, and r=-0.319; P=0.027, P=0.035, and P=0.011. Conclusion: Both DC and AC of heart rate decreased in patients with hemispheric infarction, reflecting a decrease in both vagal and sympathetic modulation. Both DC and AC were correlated with the severity of stroke. Keywords: acute ischemic stroke, autonomic dysfunction, deceleration capacity of heart rate, acceleration capacity of heart rate, heart rate variability

  17. Discovery of novel heart rate-associated loci using the Exome Chip

    DEFF Research Database (Denmark)

    van den Berg, Marten E; Warren, Helen R; Cabrera, Claudia P

    2017-01-01

    long-range regulatory chromatin interactions in heart tissue (SCD, SLF2 and MAPK8). We observed significant enrichment in DNase I hypersensitive sites in fetal heart and lung. Moreover, enrichment was seen for the first time in human neuronal progenitor cells (derived from embryonic stem cells......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 discover new genetic loci associated with heart rate from Exome Chip meta-analyses.Heart rate was measured from either elecrtrocardiograms or pulse recordings. We meta-analysed heart rate association results from 104 452 European-ancestry individuals from 30 cohorts, genotyped using the Exome Chip. Twenty...

  18. State Anxiety and Nonlinear Dynamics of Heart Rate Variability in Students

    Science.gov (United States)

    Dimitriev, Aleksey D.

    2016-01-01

    Objectives Clinical and experimental research studies have demonstrated that the emotional experience of anxiety impairs heart rate variability (HRV) in humans. The present study investigated whether changes in state anxiety (SA) can also modulate nonlinear dynamics of heart rate. Methods A group of 96 students volunteered to participate in the study. For each student, two 5-minute recordings of beat intervals (RR) were performed: one during a rest period and one just before a university examination, which was assumed to be a real-life stressor. Nonlinear analysis of HRV was performed. The Spielberger’s State-Trait Anxiety Inventory was used to assess the level of SA. Results Before adjusting for heart rate, a Wilcoxon matched pairs test showed significant decreases in Poincaré plot measures, entropy, largest Lyapunov exponent (LLE), and pointwise correlation dimension (PD2), and an increase in the short-term fractal-like scaling exponent of detrended fluctuation analysis (α1) during the exam session, compared with the rest period. A Pearson analysis indicated significant negative correlations between the dynamics of SA and Poincaré plot axes ratio (SD1/SD2), and between changes in SA and changes in entropy measures. A strong negative correlation was found between the dynamics of SA and LLE. A significant positive correlation was found between the dynamics of SA and α1. The decreases in Poincaré plot measures (SD1, complex correlation measure), entropy measures, and LLE were still significant after adjusting for heart rate. Corrected α1 was increased during the exam session. As before, the dynamics of adjusted LLE was significantly correlated with the dynamics of SA. Conclusions The qualitative increase in SA during academic examination was related to the decrease in the complexity and size of the Poincaré plot through a reduction of both the interbeat interval and its variation. PMID:26807793

  19. High intracellular Na+ preserves myocardial function at low heart rates in isolated myocardium from failing hearts.

    Science.gov (United States)

    Schillinger, Wolfgang; Teucher, Nils; Christians, Claus; Kohlhaas, Michael; Sossalla, Samuel; Van Nguyen, Phuc; Schmidt, Albrecht G; Schunck, Ortwin; Nebendahl, Klaus; Maier, Lars S; Zeitz, Oliver; Hasenfuss, Gerd

    2006-11-01

    We investigated the hypothesis that increased intracellular [Na+]i in heart failure contributes to preservation of SR Ca2+ load which may become particularly evident at slow heart rates. [Na+]i in SBFI-loaded myocytes from rabbits with pacing-induced heart failure (PHF) was significantly higher at each frequency as compared to Sham-operated animals. Furthermore, PHF rabbits demonstrated reduced SR Ca2+-ATPase protein levels (-37%, p < 0.04) but unchanged Na+/Ca2+ exchanger protein levels. At 0.25 Hz, isometric force was similar in cardiac trabeculae from PHF rabbits as compared to control (PHF, 3.6+/-1.3; Sham, 4.4+/-0.6 mN/mm2). Rapid cooling contractures (RCCs) were unchanged indicating preserved SR Ca2+ load at this frequency. In Sham, isometric twitch force increased with rising frequencies to 29.0+/-2.8 mN/mm2 at 3.0 Hz (p < 0.05) as compared to 0.25 Hz. RCCs showed a parallel increase by 186+/-47% (p < 0.01). In PHF, frequency-dependent increase in force (15.8+/-4.7 mN/mm2 at 3.0 Hz) and RCCs (increase by 70+/-40%) were significantly blunted. Thus, in PHF in rabbits SR Ca2+ load is preserved at low frequencies despite decreased SR Ca2+-ATPase expression. This may result from [Na+]i-dependent changes in Na+/Ca2+ exchanger activity.

  20. Burst Activity and Heart Rhythm Modulation in the Sympathetic Outflow to the Heart

    National Research Council Canada - National Science Library

    Baselli, G

    2001-01-01

    In 13 decerebrate, artificially ventilated cats preganglionic sympathetic outflow to the heart was recorded with ECG and ventilation signal, A novel algorithm was implemented that extracts weighted...

  1. Evoked response of heart rate variability using short-duration white noise.

    Science.gov (United States)

    Lee, Guo-She; Chen, Mei-Ling; Wang, Gin-You

    2010-06-24

    To investigate and to establish a model for evaluation of the instant cardiovascular responses to the noises of low-to-moderate intensity, sixteen healthy subjects were enrolled. The white noises were binaurally presented with a supra-aural earphone. The test intensities of noises were no noise, 50, 60, 70 and 80 dBA. Each noise was continued for 5 min and the electrocardiogram was simultaneously recorded. The cardiac autonomic responses were evaluated using power spectral analysis of the R-R contour obtained from digital signal processing of the ECG tracings. The result showed that the mean heart rate and mean blood pressure did not change significantly with the noises. However, the low-frequency power (LF) which represents cardiac autonomic modulations and the ratio (LHR) of LF to high-frequency power (HF) which reflects cardiac sympathetic modulations were significantly greater in the noise intensity of 50, 60, 70 and 80dBA (pnoise intensity (rho=0.90, pwhite noises can be detected using power spectral analysis of heart rate variability and the evoked responses may provide a sensitive way to evaluate the instant effect of noise to humans.

  2. An Overview of Heart Rate Variability Metrics and Norms

    Directory of Open Access Journals (Sweden)

    Fred Shaffer

    2017-09-01

    Full Text Available Healthy biological systems exhibit complex patterns of variability that can be described by mathematical chaos. Heart rate variability (HRV consists of changes in the time intervals between consecutive heartbeats called interbeat intervals (IBIs. A healthy heart is not a metronome. The oscillations of a healthy heart are complex and constantly changing, which allow the cardiovascular system to rapidly adjust to sudden physical and psychological challenges to homeostasis. This article briefly reviews current perspectives on the mechanisms that generate 24 h, short-term (~5 min, and ultra-short-term (<5 min HRV, the importance of HRV, and its implications for health and performance. The authors provide an overview of widely-used HRV time-domain, frequency-domain, and non-linear metrics. Time-domain indices quantify the amount of HRV observed during monitoring periods that may range from ~2 min to 24 h. Frequency-domain values calculate the absolute or relative amount of signal energy within component bands. Non-linear measurements quantify the unpredictability and complexity of a series of IBIs. The authors survey published normative values for clinical, healthy, and optimal performance populations. They stress the importance of measurement context, including recording period length, subject age, and sex, on baseline HRV values. They caution that 24 h, short-term, and ultra-short-term normative values are not interchangeable. They encourage professionals to supplement published norms with findings from their own specialized populations. Finally, the authors provide an overview of HRV assessment strategies for clinical and optimal performance interventions.

  3. Photoplethysmography pulse rate variability as a surrogate measurement of heart rate variability during non-stationary conditions

    International Nuclear Information System (INIS)

    Gil, E; Orini, M; Bailón, R; Laguna, P; Vergara, J M; Mainardi, L

    2010-01-01

    In this paper we assessed the possibility of using the pulse rate variability (PRV) extracted from the photoplethysmography signal as an alternative measurement of the HRV signal in non-stationary conditions. The study is based on analysis of the changes observed during a tilt table test in the heart rate modulation of 17 young subjects. First, the classical indices of HRV analysis were compared to the indices from PRV in intervals where stationarity was assumed. Second, the time-varying spectral properties of both signals were compared by time-frequency (TF) and TF coherence analysis. Third, the effect of replacing PRV with HRV in the assessment of the changes of the autonomic modulation of the heart rate was considered. Time-invariant HRV and PRV indices showed no statistically significant differences (p > 0.05) and high correlation (>0.97). Time-frequency analysis revealed that the TF spectra of both signals were highly correlated (0.99 ± 0.01); the difference between the instantaneous power, in the LF and HF bands, obtained from HRV and PRV was small (<10 −3 s −2 ) and their temporal patterns were highly correlated (0.98 ± 0.04 and 0.95 ± 0.06 in the LF and HF bands, respectively) and TF coherence in the LF and HF bands was high (0.97 ± 0.04 and 0.89 ± 0.08, respectively). Finally, the instantaneous power in the LF band was observed to significantly increase during head-up tilt by both HRV and PRV analysis. These results suggest that although some differences in the time-varying spectral indices extracted from HRV and PRV exist, mainly in the HF band associated with respiration, PRV could be used as a surrogate of HRV during non-stationary conditions, at least during the tilt table test

  4. Separating the effect of respiration from the heart rate variability for cases of constant harmonic breathing

    Directory of Open Access Journals (Sweden)

    Kircher Michael

    2015-09-01

    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.

  5. Relative influence of age, resting heart rate and sedentary life style in short-term analysis of heart rate variability

    Directory of Open Access Journals (Sweden)

    E.R. Migliaro

    2001-04-01

    Full Text Available In order to assess the relative influence of age, resting heart rate (HR and sedentary life style, heart rate variability (HRV was studied in two different groups. The young group (YG consisted of 9 sedentary subjects aged 15 to 20 years (YG-S and of 9 nonsedentary volunteers (YG-NS also aged 15 to 20. The elderly sedentary group (ESG consisted of 16 sedentary subjects aged 39 to 82 years. HRV was assessed using a short-term procedure (5 min. R-R variability was calculated in the time-domain by means of the root mean square successive differences. Frequency-domain HRV was evaluated by power spectrum analysis considering high frequency and low frequency bands. In the YG the effort tolerance was ranked in a bicycle stress test. HR was similar for both groups while ESG showed a reduced HRV compared with YG. Within each group, HRV displayed a negative correlation with HR. Although YG-NS had better effort tolerance than YG-S, their HR and HRV were not significantly different. We conclude that HRV is reduced with increasing HR or age, regardless of life style. The results obtained in our short-term study agree with others of longer duration by showing that age and HR are the main determinants of HRV. Our results do not support the idea that changes in HRV are related to regular physical activity.

  6. Relative influence of age, resting heart rate and sedentary life style in short-term analysis of heart rate variability.

    Science.gov (United States)

    Migliaro, E R; Contreras, P; Bech, S; Etxagibel, A; Castro, M; Ricca, R; Vicente, K

    2001-04-01

    In order to assess the relative influence of age, resting heart rate (HR) and sedentary life style, heart rate variability (HRV) was studied in two different groups. The young group (YG) consisted of 9 sedentary subjects aged 15 to 20 years (YG-S) and of 9 nonsedentary volunteers (YG-NS) also aged 15 to 20. The elderly sedentary group (ESG) consisted of 16 sedentary subjects aged 39 to 82 years. HRV was assessed using a short-term procedure (5 min). R-R variability was calculated in the time-domain by means of the root mean square successive differences. Frequency-domain HRV was evaluated by power spectrum analysis considering high frequency and low frequency bands. In the YG the effort tolerance was ranked in a bicycle stress test. HR was similar for both groups while ESG showed a reduced HRV compared with YG. Within each group, HRV displayed a negative correlation with HR. Although YG-NS had better effort tolerance than YG-S, their HR and HRV were not significantly different. We conclude that HRV is reduced with increasing HR or age, regardless of life style. The results obtained in our short-term study agree with others of longer duration by showing that age and HR are the main determinants of HRV. Our results do not support the idea that changes in HRV are related to regular physical activity.

  7. Photovoltaic module energy rating procedure. Final subcontract report

    Energy Technology Data Exchange (ETDEWEB)

    Whitaker, C.M.; Newmiller, J.D. [Endecon Engineering (United States)

    1998-01-01

    This document describes testing and computation procedures used to generate a photovoltaic Module Energy Rating (MER). The MER consists of 10 estimates of the amount of energy a single module of a particular type (make and model) will produce in one day. Module energy values are calculated for each of five different sets of weather conditions (defined by location and date) and two load types. Because reproduction of these exact testing conditions in the field or laboratory is not feasible, limited testing and modeling procedures and assumptions are specified.

  8. Perinatal hypothyroidism modulates antioxidant defence status in the developing rat liver and heart.

    Science.gov (United States)

    Zhang, Hongmei; Dong, Yan; Su, Qing

    2017-02-01

    In the present study, we investigated oxidative stress parameters and antioxidant defence status in perinatal hypothyroid rat liver and heart. We found that the proteincarbonyl content did not differ significantly between the three groups both in the pup liver and in the heart. The OH˙ level was significantly decreased in the hypothyroid heart but not in the liver compared with controls. A slight but not significant decrease in SOD activity was observed in both perinatal hypothyroid liver and heart. A significantly increased activity of CAT was observed in the liver but not in the heart of hypothyroid pups. The GPx activity was considerably increased compared with controls in the perinatal hypothyroid heart and was unaltered in the liver of hypothyroid pups. We also found that vitamin E levels in the liver decreased significantly in hypothyroidism and were unaltered in the heart of perinatal hypothyroid rats. The GSH content was elevated significantly in both hypothyroid liver and heart. The total antioxidant capacity was higher in the liver of the hypothyroid group but not in the hypothyroid heart. Thyroxine replacement could not repair the above changes to normal. In conclusion, perinatal hypothyroidism modulates the oxidative stress status of the perinatal liver and heart.

  9. Heart rate regulation and extreme bradycardia in diving emperor penguins.

    Science.gov (United States)

    Meir, Jessica U; Stockard, Torre K; Williams, Cassondra L; Ponganis, Katherine V; Ponganis, Paul J

    2008-04-01

    To investigate the diving heart rate (f(H)) response of the emperor penguin (Aptenodytes forsteri), the consummate avian diver, birds diving at an isolated dive hole in McMurdo Sound, Antarctica were outfitted with digital electrocardiogram recorders, two-axis accelerometers and time depth recorders (TDRs). In contrast to any other freely diving bird, a true bradycardia (f(H) significantly emperor penguins. Maximum instantaneous surface interval f(H) in this study is the highest ever recorded for emperor penguins (256 beats min(-1)), equivalent to f(H) at V(O(2)) max., presumably facilitating oxygen loading and post-dive metabolism. The classic Scholander-Irving dive response in these emperor penguins contrasts with the absence of true bradycardia in diving ducks, cormorants, and other penguin species.

  10. [Comparison of heart rate variability measurements between ballistocardiogram and electrocardiography].

    Science.gov (United States)

    Wang, Kun; Zhu, Tiangang; Zhang, Xianwen; Yu, Chao; Cao, Xinrong; Tang, Jintian; Wan, Zheng

    2015-05-01

    To compare the heart rate variability (HRV) measurements between ballistocardiogram (BCG) and electrocardiography (ECG). The signals of BCG and ECG of 21 patients were collected synchronously. JJ intervals of BCG and RR intervals of ECG were used to calculate the cardiac periods. The parameters of HRV analysis were calculated in time domain analysis, frequency domain analysis and nonlinear analysis. The results derived from BCG and ECG were compared. The parameters of HRV analysis calculated from BCG and ECG had high similarity. The correlation coefficients of SDNN, TP, LF, HF and SD2 between the BCG and ECG methods were high (r = 1). The correlation coefficients of rMSSD and SD2 were 0.99 and of PNN50 and LF/HF were 0.98 between the two methods. HRV analysis results derived from the two methods were similar (P > 0.05). HRV could also be measured reliably by calculating the JJ interval from BCG.

  11. Entertainment Capture through Heart Rate Activity in Physical Interactive Playgrounds

    DEFF Research Database (Denmark)

    Yannakakis, Georgios; Hallam, John; Lund, Henrik Hautop

    2008-01-01

    An approach for capturing and modeling individual entertainment (“fun”) preferences is applied to users of the innovative Playware playground, an interactive physical playground inspired by computer games, in this study. The goal is to construct, using representative statistics computed from...... that predict reported entertainment preferences given HR features. These models are expressed as artificial neural networks and are demonstrated and evaluated on two Playware games and two control tasks requiring physical activity. The best network is able to correctly match expressed preferences in 64...... children’s physiological signals, an estimator of the degree to which games provided by the playground engage the players. For this purpose children’s heart rate (HR) signals, and their expressed preferences of how much “fun” particular game variants are, are obtained from experiments using games...

  12. Heart rate variability analysis with the R package RHRV

    CERN Document Server

    García Martínez, Constantino Antonio; Vila, Xosé A; Lado Touriño, María José; Rodríguez-Liñares, Leandro; Rodríguez Presedo, Jesús María; Méndez Penín, Arturo José

    2017-01-01

    This book introduces readers to the basic concepts of Heart Rate Variability (HRV) and its most important analysis algorithms using a hands-on approach based on the open-source RHRV software. HRV refers to the variation over time of the intervals between consecutive heartbeats. Despite its apparent simplicity, HRV is one of the most important markers of the autonomic nervous system activity and it has been recognized as a useful predictor of several pathologies. The book discusses all the basic HRV topics, including the physiological contributions to HRV, clinical applications, HRV data acquisition, HRV data manipulation and HRV analysis using time-domain, frequency-domain, time-frequency, nonlinear and fractal techniques. Detailed examples based on real data sets are provided throughout the book to illustrate the algorithms and discuss the physiological implications of the results. Offering a comprehensive guide to analyzing beat information with RHRV, the book is intended for masters and Ph.D. students in v...

  13. Algorithms for Computerized Fetal Heart Rate Diagnosis with Direct Reporting

    Directory of Open Access Journals (Sweden)

    Kazuo Maeda

    2015-06-01

    Full Text Available Aims: Since pattern classification of fetal heart rate (FHR was subjective and enlarged interobserver difference, objective FHR analysis was achieved with computerized FHR diagnosis. Methods: The computer algorithm was composed of an experts’ knowledge system, including FHR analysis and FHR score calculation, and also of an objective artificial neural network system with software. In addition, a FHR frequency spectrum was studied to detect ominous sinusoidal FHR and the loss of baseline variability related to fetal brain damage. The algorithms were installed in a central-computerized automatic FHR monitoring system, which gave the diagnosis rapidly and directly to the attending doctor. Results: Clinically perinatal mortality decreased significantly and no cerebral palsy developed after introduction of the centralized system. Conclusion: The automatic multichannel FHR monitoring system improved the monitoring, increased the objectivity of FHR diagnosis and promoted clinical results.

  14. Effect of atrioventricular conduction on heart rate variability

    KAUST Repository

    Ahmad, Talha Jamal

    2011-08-01

    This paper discusses the effect of atrioventricular conduction time (AVCT) on the short-term Heart Rate Variability (HRV) by computing HRV parameters using intervals between the onsets of successive P waves (PP time series) for three groups: normal, arrhythmia and sudden cardiac death (SCD) patients. A very precise wavelet transform based ECG delineator was developed to detect PP, PR and RR time series. Mean PR variation in arrhythmia and SCD group was found to be significantly high as compared to the normal group. It was observed that when PR variations in arrhythmia and SCD cases crossed a certain threshold, RR variability no longer provided a very accurate estimate of HRV. In such cases, PP variability was able to provide a better assessment of HRV. © 2011 IEEE.

  15. Automated Fetal Heart Rate Analysis in Labor: Decelerations and Overshoots

    Science.gov (United States)

    Georgieva, A. E.; Payne, S. J.; Moulden, M.; Redman, C. W. G.

    2010-10-01

    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.

  16. Fetal magnetocardiography: time intervals and heart rate variability.

    Science.gov (United States)

    Van Leeuwen, P

    2004-11-30

    Biomagnetism in the perinatal domain has been dominated by fetal cardiology, and early work pointed out the potential of both fetal cardiac time intervals (CTI) and heart rate variability (HRV) for future clinical applications. Recent improvements in instrumentation have permitted numerous groups to investigate a substantial number of healthy fetuses in these two areas and to lay the groundwork for a delineation of normal ranges. With respect to fetal CTI it is now clear that in particular the duration of P wave, PR interval and QRS complex reflect fetal growth and development. Preliminary studies have shown that the age-adjusted CTI are shorter in growth-retarded fetuses and altered in cases of structural cardiac defects and in specific types of arrhythmia. Less work has been published on MCG-determined fetal HRV although parameters from both the time and frequency domains as well as complexity have been examined. Concomitant with the gradual change in heart rate during pregnancy, increases in time domain variables and complexity have been described for normal pregnancies. Furthermore, gestational age-related changes in specific spectral bands have been noted and increases in power have been documented at frequencies which are associated with fetal breathing movements. The fact that little has been reported to date on discriminatory power with respect to pathological states may be due to the lack of extended data acquisition in a clinical setting documenting acute states. Nonetheless, it may be expected that both fetal HRV and CTI will supplement standard fetal surveillance techniques in the near future.

  17. Cuff inflation during ambulatory blood pressure monitoring and heart rate

    Directory of Open Access Journals (Sweden)

    Mia Skov-Madsen

    2008-11-01

    Full Text Available Mia Skov-Madsen, My Svensson, Jeppe Hagstrup ChristensenDepartment of Nephrology, Aarhus University Hospital, Aalborg, DenmarkIntroduction: Twenty four-hour ambulatory blood pressure monitoring is a clinically validated procedure in evaluation of blood pressure (BP. We hypothesised that the discomfort during cuff inflation would increase the heart rate (HR measured with 24-h ambulatory BP monitoring compared to a following HR measurement with a 24-h Holter monitor.Methods: The study population (n = 56 were recruited from the outpatient’s clinic at the Department of Nephrology, Aalborg Hospital, Aarhus University Hospital at Aalborg, Denmark. All the patients had chronic kidney disease (CKD. We compared HR measured with a 24-h Holter monitor with a following HR measured by a 24-h ambulatory BP monitoring.Results: We found a highly significant correlation between the HR measured with the Holter monitor and HR measured with 24-h ambulatory blood pressure monitoring (r = 0.77, p < 0.001. Using the Bland-Altman plot, the mean difference in HR was only 0.5 beat/min during 24 hours with acceptable limits of agreement for both high and low HR levels. Dividing the patients into groups according to betablocker treatment, body mass index, age, sex, angiotensin-converting enzyme inhibitor treatment, statins treatment, diuretic treatment, or calcium channel blocker treatment revealed similar results as described above.Conclusion: The results indicate that the discomfort induced by cuff inflation during 24-h ambulatory BP monitoring does not increase HR. Thus, 24-h ambulatory BP monitoring may be a reliable measurement of the BP among people with CKD.Keywords: ambulatory blood pressure monitoring, Holter monitoring, heart rate, chronic kidney disease, hypertension

  18. Venipuncture procedure affects heart rate variability and chronotropic response.

    Science.gov (United States)

    Kliszczewicz, Brian; Esco, Michael R; E Bechke, Emily; Feito, Yuri; M Williamson, Cassie; Brown, Danielle; Price, Brandi

    2017-10-01

    Heart rate variability (HRV) has been shown to be influenced by several factors such as noise, sleep status, light, and emotional arousal; however, little evidence is available concerning autonomic responses to a venipuncture. The purpose of this study was to investigate changes of HRV indexes and heart rate (HR) during and following a venipuncture procedure among healthy individuals. 33 healthy individuals (22.8 ± 0.56 years, 167 ± 1.56 cm, 69.5 ± 2.61 kg) participated. Testing included 10-minute HRV analysis prior to the venipuncture, a 1-minute venipuncture procedure followed by a 10-minute analysis of HRV, and a total recording of 21 minutes. The first 5 minutes of the 21-minute recordings were discarded, and the remaining 5 minutes of the resting segment was analyzed (PRE), and the last 5 minutes of the 21-minute recording (POST). The log transformation of the time domain root mean squared of successive differences (lnRMSSD) and the frequency domains of high frequency (lnHF) and low frequency (lnLF) and LF/HF ratio (lnLF/HF) were used to quantify autonomic activity. HR was measured in 1-minute segments at 2 minutes prior (PRE), venipuncture (STICK), and post (P1-5). HR significantly increased at STICK (P = 0.002), and fell below resting at P-5 (P venipuncture procedure. Practitioners and researchers who are interested in collecting blood and measuring HRV need to account for the influence of the venipuncture. © 2017 Wiley Periodicals, Inc.

  19. Heart rate variability in porcine progressive peritonitis-induced sepsis

    Directory of Open Access Journals (Sweden)

    Dagmar eJarkovska

    2016-01-01

    Full Text Available Accumulating evidence suggests that heart rate variability (HRV alterations could serve as an indicator of sepsis progression and outcome, however, the relationships of HRV and major pathophysiological processes of sepsis remain unclear. Therefore, in this experimental study HRV was investigated in a clinically relevant long-term porcine model of severe sepsis/septic shock. HRV was analyzed by several methods and the parameters were correlated with pathophysiological processes of sepsis.In 16 anesthetized, mechanically ventilated and instrumented domestic pigs of either gender, sepsis was induced by fecal peritonitis. Experimental subjects were screened up to the refractory shock development or death. ECG was continuously recorded throughout the experiment, afterwards RR intervals were detected and HRV parameters computed automatically using custom made measurement and analysis MATLAB routines. In all septic animals, progressive hyperdynamic septic shock developed. The statistical measures of HRV, geometrical measures of HRV and Poincaré plot analysis revealed a pronounced reduction of HRV that developed quickly upon the onset of sepsis and was maintained throughout the experiment. The frequency domain analysis demonstrated a decrease in the high frequency component and increase in the low frequency component together with an increase of the low/high frequency component ratio. The reduction of HRV parameters preceded sepsis-associated hemodynamic changes including heart rate increase or shock progression.In a clinically relevant porcine model of peritonitis-induced progressive septic shock, reduction of HRV parameters heralded sepsis development. HRV reduction was associated with a pronounced parasympathetic inhibition and a shift of sympathovagal balance. Early reduction of HRV may serve as a non-invasive and sensitive marker of systemic inflammatory syndrome, thereby widening the therapeutic window for early interventions.

  20. Spectral analyses of systolic blood pressure and heart rate variability and their association with cognitive performance in elderly hypertensive subjects.

    Science.gov (United States)

    Santos, W B; Matoso, J M D; Maltez, M; Gonçalves, T; Casanova, M; Moreira, I F H; Lourenço, R A; Monteiro, W D; Farinatti, P T V; Soares, P P; Oigman, W; Neves, M F T; Correia, M L G

    2015-08-01

    Systolic hypertension is associated with cognitive decline in the elderly. Altered blood pressure (BP) variability is a possible mechanism of reduced cognitive performance in elderly hypertensives. We hypothesized that altered beat-to-beat systolic BP variability is associated with reduced global cognitive performance in elderly hypertensive subjects. In exploratory analyses, we also studied the correlation between diverse discrete cognitive domains and indices of systolic BP and heart rate variability. Disproving our initial hypothesis, we have shown that hypertension and low education, but not indices of systolic BP and heart rate variability, were independent predictors of lower global cognitive performance. However, exploratory analyses showed that the systolic BP variability in semi-upright position was an independent predictor of matrix reasoning (B = 0.08 ± .03, P-value = 0.005), whereas heart rate variability in semi-upright position was an independent predictor of the executive function score (B = -6.36 ± 2.55, P-value = 0.02). We conclude that myogenic vascular and sympathetic modulation of systolic BP do not contribute to reduced global cognitive performance in treated hypertensive subjects. Nevertheless, our results suggest that both systolic BP and heart rate variability might be associated with modulation of frontal lobe cognitive domains, such as executive function and matrix reasoning.

  1. The influence of betamethasone on fetal heart rate variability, obtained by non-invasive fetal electrocardiogram recordings.

    Science.gov (United States)

    Verdurmen, Kim M J; Warmerdam, Guy J J; Lempersz, Carlijn; Hulsenboom, Alexandra D J; Renckens, Joris; Dieleman, Jeanne P; Vullings, Rik; van Laar, Judith O E H; Oei, S Guid

    2018-03-02

    Betamethasone is widely used to enhance fetal lung maturation in case of threatened preterm labour. Fetal heart rate variability is one of the most important parameters to assess in fetal monitoring, since it is a reliable indicator for fetal distress. To describe the effect of betamethasone on fetal heart rate variability, by applying spectral analysis on non-invasive fetal electrocardiogram recordings. Prospective cohort study. Patients that require betamethasone, with a gestational age from 24 weeks onwards. Fetal heart rate variability parameters on day 1, 2, and 3 after betamethasone administration are compared to a reference measurement. Following 68 inclusions, 12 patients remained with complete series of measurements and sufficient data quality. During day 1, an increase in absolute fetal heart rate variability values was seen. During day 2, a decrease in these values was seen. All trends indicate to return to pre-medication values on day 3. Normalised high- and low-frequency power show little changes during the study period. The changes in fetal heart rate variability following betamethasone administration show the same pattern when calculated by spectral analysis of the fetal electrocardiogram, as when calculated by cardiotocography. Since normalised spectral values show little changes, the influence of autonomic modulation seems minor. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Estimating 'lost heart beats' rather than reductions in heart rate during the intubation of critically-ill children.

    Directory of Open Access Journals (Sweden)

    Peter Jones

    Full Text Available PURPOSE: 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. METHODS: 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 finally the estimate the numbers of lost beats. RESULTS: 333 intubations in children were eligible for inclusion of which 245 were available for analysis (74%. Intubations where the fall in heart rate was less than 50 bpm were accompanied almost exclusively by less than 25 lost beats (n = 175, median 0 [0-1]. When there was a reduction of >50 bpm there was a poor correlation with numbers of lost beats (n = 70, median 42 [15-83]. During intubation the median number of lost beats was 8 [1]-[32] when atropine was not used compared to 0 [0-0] when atropine was used (p50 bpm the heart rate was poorly predictive of lost beats. A study looking at the relationship between lost beats and cardiac output needs to be performed. Atropine reduces both fall in heart rate and loss of beats. Similar area-under-the-curve methodology may be useful for estimating risk when biological parameters deviate outside normal range.

  3. [The exercise training restores the heart rate variability in heart failure patients. A systematic review].

    Science.gov (United States)

    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.

  4. The impact of mean first-year heart rate on outcomes after heart transplantation: does it make a difference?

    Science.gov (United States)

    Shah, Ankit B; Patel, Jignesh K; Rafiei, Matthew; Morrissey, Ryan P; Kittleson, Michelle M; Kobashigawa, Jon A

    2013-01-01

    Cardiac denervation following transplantation has a variable effect on heart rate (HR), and the consequence of this is not known. We examined the impact of first-year HR on five-yr outcomes after heart transplant. We evaluated 544 heart transplant recipients from 1994 to 2008. Patients were divided into groups by mean first-year HR: group 1, HR heart failure (CHF) in group 3 over five yr. Mean first-year HR does not provide prognostic significance for one-yr freedom from treated rejection, five-yr survival or development of CAV five yr after heart transplant. These results suggest that HR post-heart transplantation does not affect long-term outcomes, but high first-year HRs may be associated with new-onset CHF. © 2013 John Wiley & Sons A/S.

  5. Resonance of about-weekly human heart rate rhythm with solar activity change.

    Science.gov (United States)

    Cornelissen, G; Halberg, F; Wendt, H W; Bingham, C; Sothern, R B; Haus, E; Kleitman, E; Kleitman, N; Revilla, M A; Revilla, M; Breus, T K; Pimenov, K; Grigoriev, A E; Mitish, M D; Yatsyk, G V; Syutkina, E V

    1996-12-01

    In several human adults, certain solar activity rhythms may influence an about 7-day rhythm in heart rate. When no about-weekly feature was found in the rate of change in sunspot area, a measure of solar activity, the double amplitude of a circadian heart rate rhythm, approximated by the fit of a 7-day cosine curve, was lower, as was heart rate corresponds to about-weekly features in solar activity and/or relates to a sunspot cycle.

  6. High repetition rate driver circuit for modulation of injection lasers

    International Nuclear Information System (INIS)

    Dornan, B.R.; Goel, J.; Wolkstein, H.J.

    1981-01-01

    An injection laser modulator comprises a self-biased field effect transistor (FET) and an injection laser to provide a quiescent state during which lasing of the injection laser occurs in response to a high repetition rate signal of pulse coded modulation (pcm). The modulator is d.c. coupled to an input pulse source of pcm rendering it compatible with an input pulse referenced to ground and not being subject to voltage level shifting of the input pulse. The modulator circuit in its preferred and alternate embodiments provides various arrangements for high impedance input and low impedance output matching. In addition, means are provided for adjusting the bias of the FET as well as the bias of the injection laser

  7. Short-term Parameters of Heart Rate Variability During Balanced Anaesthesia with Administration of Two Different Inhalation Anaesthetics.

    Science.gov (United States)

    Omerbegović, Meldijana

    2014-08-01

    Heart rate variability which denotes variations of the length of consecutive heart cycles has been suggested to reflect the modulation of heart rate by autonomic nervous system. Sixty four patients of ASA I and ASA II status scheduled for elective abdominal surgical procedures were randomly allocated to group 1 and group 2. Premedication and induction of anaesthesia were performed with same agents. After orotracheal intubation maintenance of balanced anaesthesia was based on administration of same induction agents,opioids and muscle relaxant while delivery of gaseous mixture with sevoflurane in the group 1 (n=32) and isoflurane in the group 2(n=32). Haemodynamic parameters were monitored in perioperative and electrocardiogram was recorded by holter ECG recorder, while the analysis of the parameters were performed by corresponding softwares . Data were presented as mean values of logarithmic (natural logarithm) values of the power of the total spectrum of heart rate variability(TP), mean values of the logarithmic values of low frequency band (LF), mean values of the logarithmic values of high frequency range(HF), and mean values of SD1 and SD2 parameters. Analysis of the values of hemodynamic parameters has shown changes of haemodynamic parameters during perioperative period without significant statistical differences between the groups. Analysis of the logarhitmic values of parameters of heart rate variability of frequency domain has shown changes of the total spectrum power and LF and HF spestra with variations of the values of total power spectrum and individual components of the spectrum of heart rate variability during the balanced anaesthesia with administration of two different inhalation anaesthetics, without statistically significant differences between the groups. The results have shown that during balanced anaesthesia with two different inhalation anaesthetics there are variations of haemodynamic variables and parameters of heart rate variability without

  8. Changes in Respiratory Rate, Blood Pressure and Heart Rate Variability in Rabbits during Orthostasis

    Directory of Open Access Journals (Sweden)

    J. Mokrý

    2006-01-01

    Full Text Available The purpose of the study was to evaluate the changes of respiratory rate, systemic blood pressure and heart rate variability parameters (HRV during orthostasis in anaesthetized rabbits. Furthermore, these changes were influenced by affecting the renin-angiotensin-aldosterone (RAA system and autonomic nervous system (ANS to study the mechanisms participating in activity of spectral frequency bands of HRV in rabbits. Ten adult rabbits (Chinchilla were anaesthetized by ketamine and flunitrazepam. The systemic blood pressure, tidal volume and respiratory rate were measured. HRV was evaluated by microcomputer system VariaPulse TF3E. The R-R intervals were derived from the electrocardiogram signal from subcutaneous needle electrodes. The evaluation of HRV in very low (VLF; 0.01-0.05 Hz, low (LF; 0.05-0.15 Hz and high frequency bands (HF; 0.15-2.0 Hz was made and parameters of frequency and time analysis were calculated. The measurements were made in horizontal (supine position, in orthostasis (the angle of 60 ° and again in supine position before and after enalapril (0.5 mg/kg b.w., metipranolol (0.2 mg/kg b.w., and after subsequent bilateral cervical vagotomy. The orthostasis in anaesthetized rabbits is accompanied by depression of respiratory rate reversed only by vagotomy. Furthermore, decrease of systemic blood pressure, unchanged heart rate and increased characteristics of heart rate variability were found, with predominant increase of spectral power in LF and VLF bands. This elevation can be eliminated only by complete blockade of ANS. Although the participation of ANS or RAA system in modification of individual HRV frequency bands is not as specific as in humans, we confirmed the participation of RAA system in determination of the VLF band.

  9. Do mobile phones pose a potential risk to autonomic modulation of the heart?

    Science.gov (United States)

    Barutcu, Irfan; Esen, Ali Metin; Kaya, Dayimi; Turkmen, Muhsin; Karakaya, Osman; Saglam, Mustafa; Melek, Mehmet; Çelik, Ataç; Kilit, Celal; Onrat, Ersel; Kirma, Cevat

    2011-11-01

    It has long been speculated that mobile phones may interact with the cardiac devices and thereby cardiovascular system may be a potential target for the electromagnetic fields emitted by the mobile phones. Therefore, the present study was designed to test possible effects of radiofrequency waves emitted by digital mobile phones on cardiac autonomic modulation by short-time heart rate variability (HRV) analysis. A total of 20 healthy young subjects were included to the study. All participants were rested in supine position at least for 15 minutes on a comfortable bed, and then time and frequency domain HRV parameters were recorded at baseline in supine position for 5 minutes. After completion of baseline records, by using a mobile GSM (Global System for Mobile Communication) phone, HRV parameters were recorded at turned off mode, at turned on mode, and at calling mode over 5 minutes periods for each stage. Neither time nor frequency domain HRV parameters altered significantly during off mode compare to their baseline values. Also, neither time nor frequency domain HRV parameters altered significantly during turned on and calling mode compared to their baseline values. Short-time exposure to electromagnetic fields emitted by mobile phone does not affect cardiac autonomic modulation in healthy subjects.

  10. The Performance of Short-Term Heart Rate Variability in the Detection of Congestive Heart Failure

    Directory of Open Access Journals (Sweden)

    Fausto Lucena

    2016-01-01

    Full Text Available Congestive heart failure (CHF is a cardiac disease associated with the decreasing capacity of the cardiac output. It has been shown that the CHF is the main cause of the cardiac death around the world. Some works proposed to discriminate CHF subjects from healthy subjects using either electrocardiogram (ECG or heart rate variability (HRV from long-term recordings. In this work, we propose an alternative framework to discriminate CHF from healthy subjects by using HRV short-term intervals based on 256 RR continuous samples. Our framework uses a matching pursuit algorithm based on Gabor functions. From the selected Gabor functions, we derived a set of features that are inputted into a hybrid framework which uses a genetic algorithm and k-nearest neighbour classifier to select a subset of features that has the best classification performance. The performance of the framework is analyzed using both Fantasia and CHF database from Physionet archives which are, respectively, composed of 40 healthy volunteers and 29 subjects. From a set of nonstandard 16 features, the proposed framework reaches an overall accuracy of 100% with five features. Our results suggest that the application of hybrid frameworks whose classifier algorithms are based on genetic algorithms has outperformed well-known classifier methods.

  11. The Effect of Valsartan on Heart Rate Variability and Heart Rate Recovery in Patients with Mild to Moderate Mitral Stenosis

    Directory of Open Access Journals (Sweden)

    Ali Metin Esen

    2010-04-01

    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.

  12. Effects of prenatal visual stimulation on growth and heart rate in bobwhite quail (Colinus virginianus).

    Science.gov (United States)

    Sleigh, Merry J; Birchard, Geoffrey

    2006-05-01

    This study examined the effects of prenatal visual stimulation on bobwhite quail embryos' growth and heart rate. No differences in growth rate were found between embryos exposed to visual stimulation during the late prenatal period and control embryos. Embryos exposed to visual stimulation throughout incubation maintained lower heart rates in response to visual stimulation than did naïve embryos. In a subsequent experiment, naïve embryos that underwent an egg-opening procedure exhibited heart rates that were lower than embryos measured in intact eggshells. Embryos in opened eggs maintained lower heart rates than comparison embryos across time; however, a less invasive egg-opening procedure led to a quicker heart rate recovery than did a more invasive egg-opening procedure. These findings indicate that prenatal heart rate responses may be mediated by multiple features of the organism's developmental context, including intensity and duration of sensory stimulation. (c) 2006 Wiley Periodicals, Inc.

  13. False Heart Rate Feedback and the Perception of Heart Symptoms in Patients with Congenital Heart Disease and Anxiety

    NARCIS (Netherlands)

    Karsdorp, Petra A.; Kindt, Merel; Rietveld, Simon; Everaerd, Walter; Mulder, Barbara J. M.

    2009-01-01

    Background Little is known about the mechanisms explaining an increased perception of heart symptoms in congenital heart disease (ConHD). In the present study, it was suggested that a combination of high trait anxiety and disease history increases the perception of heart symptoms. Purpose It was

  14. False heart rate feedback and the perception of heart symptoms in patients with congenital heart disease and anxiety

    NARCIS (Netherlands)

    Karsdorp, P.A.; Kindt, M.; Rietveld, S.; Everaerd, W.; Mulder, B.J.M.

    2009-01-01

    Background: Little is known about the mechanisms explaining an increased perception of heart symptoms in congenital heart disease (ConHD). In the present study, it was suggested that a combination of high trait anxiety and disease history increases the perception of heart symptoms. Purpose: It was

  15. Short- and long-term variations in non-linear dynamics of heart rate variability

    DEFF Research Database (Denmark)

    Kanters, J K; Højgaard, M V; Agner, E

    1996-01-01

    OBJECTIVES: The purpose of the study was to investigate the short- and long-term variations in the non-linear dynamics of heart rate variability, and to determine the relationships between conventional time and frequency domain methods and the newer non-linear methods of characterizing heart rate...... rate and describes mainly linear correlations. Non-linear predictability is correlated with heart rate variability measured as the standard deviation of the R-R intervals and the respiratory activity expressed as power of the high-frequency band. The dynamics of heart rate variability changes suddenly...

  16. Reliability of heart rate mobile apps in young healthy adults: exploratory study and research directions

    Directory of Open Access Journals (Sweden)

    Maria Parpinel

    2017-06-01

    Full Text Available Background: Recently, a number of smartphone apps appeared that allow for heart rate measurements basing on the photoplethysmography principle. In fact, almost every smartphone now has a camera with flash that could be used for that. Some studies appeared on the reliability of some of those apps, with heterogeneous results. Objectives: The present study aims at adding up evidence in particular during physical activity, by comparing 3 apps on two different platforms (IOs and Android, on a broad range of heart rates. As gold standard, heart rate has been measured with a traditional heart rate monitor. Results: The results suggest that heart rate apps might be used for measuring heart rate for fitness aims for many individuals, but further research is needed to i analyse influence of smartphone features; ii identify personal factors hindering measurements, and iii verify reliability on different measurement sites.

  17. Approximate entropy and point correlation dimension of heart rate variability in healthy subjects

    DEFF Research Database (Denmark)

    Storella, R J; Wood, H W; Mills, K M

    1999-01-01

    The contribution of nonlinear dynamics to heart rate variability in healthy humans was examined using surrogate data analysis. Several measures of heart rate variability were used and compared. Heart rates were recorded for three hours and original data sets of 8192 R-R intervals created. For each...... original data set (n = 34), three surrogate data sets were made by shuffling the order of the R-R intervals while retaining their linear correlations. The difference in heart rate variability between the original and surrogate data sets reflects the amount of nonlinear structure in the original data set....... Heart rate variability was analyzed by two different nonlinear methods, point correlation dimension and approximate entropy. Nonlinearity, though under 10 percent, could be detected with both types of heart rate variability measures. More importantly, not only were the correlations between...

  18. Heart rate variability is severely impaired among type 2 diabetic patients with hypertension.

    Science.gov (United States)

    Istenes, Ildikó; Körei, Anna Erzsébet; Putz, Zsuzsanna; Németh, Nóra; Martos, Timea; Keresztes, Katalin; Kempler, Miklós Soma; Erzsébet, Vági Orsolya; Vargha, Péter; Kempler, Péter

    2014-05-01

    The aim of our study was to evaluate the relative effect of diabetes and hypertension on heart rate variability. Four age-matched groups including type 2 diabetic patients with and without hypertension, non-diabetic patients with essential hypertension and healthy control subjects were studied. Autonomic function was evaluated by the standard cardiovascular reflex tests and 24-hour heart rate variability measurement. Heart rate variability was characterized by the triangular index value and by the spectral components of the frequency domain analysis. According to the two-way analysis of variance on ranks, all parameters were influenced negatively by diabetes (heart rate variability triangular index: p heart rate variability parameters are additive. Beat-to-beat variation upon deep breathing, the most sensitive cardiovascular reflex test was also negatively influenced by both diabetes (p heart rate variability. Early assessment of the autonomic nerve function is suggested in diabetic patients with hypertension. Copyright © 2013 John Wiley & Sons, Ltd.

  19. Effects of a swimming program on infants' heart rate response.

    Science.gov (United States)

    Costa, Mario J; Barbosa, Tiago M; Ramos, Alberto; Marinho, Daniel A

    2016-04-01

    The physiological response has been used to characterize or estimate physical demands while exercising. The aim of this study was to analyze the infant's physiological adaptations over an intervention water program. Fourteen infants (36±5.08 months old) were tested before (M1) and 4 months after (M2) a well-designed swimming program aiming to develop aquatic readiness, cognitive behavior and social interaction. The physiological response was assessed based on heart rate measurements (HR, bpm) at a sampling rate of 1 Hz during several basic aquatic motor skills: 1) individual displacement in ventral position (HR@InD); 2) Individual displacement in vertical position (HR@VD); 3) immersion (HR@Im); 4) voluntary underwater displacement (HR@UnD); 5) jump from the deck (HR@JD); 6) jump from the swimming mat (HR@JM); 7) from a swimming slider (HR@Sli). The HR@Im showed the lowest values (~119 bpm) at the end of the program. Main trend was for a HR decreased over time (HR@Im: -14.17±17.76%; HR@InD: -8.16±9.16%; HR@JD: -10.36±12.70%; HR@Sli: -3.48±6.40%. In all other skills, HR remained unchanged. Our findings suggest that infants experience significant hear rate adaptations while participating on a swimming program. The HR decreases suggests a higher capability to perform the basic aquatic motor skills and a less stressful behavior through the lessons.

  20. Interaction of prostaglandins and angiotensin II in the modulation of renal function in congestive heart failure.

    Science.gov (United States)

    Packer, M

    1988-06-01

    Despite a dramatic fall in renal blood flow, glomerular filtration rate is usually preserved in patients with congestive heart failure until the terminal stages of the disease. This maintenance of renal function appears to be achieved in part by the synthesis of two vasoactive factors within the kidney--angiotensin II and prostaglandins--which are rapidly released whenever renal perfusion is compromised or sympathetic nerve traffic to the kidneys is increased. Although these two hormonal systems exert opposite effects on systemic and renal blood flow and sodium and water excretion, both act to preserve glomerular filtration rate: prostaglandins by a vasodilator action exerted primarily on the afferent arteriole and angiotensin II by a vasoconstrictor effect on the efferent arteriole. Consequently, when the synthesis of these hormones is experimentally blocked, renal function deteriorates, especially in subjects with marked renal hypoperfusion and sodium depletion; these two factors interact to determine the importance of intrarenal hormonal release in the modulation of renal function. Clinically, four specific factors have been identified that predispose patients with heart failure to the development of functional renal insufficiency after treatment with converting-enzyme or cyclo-oxygenase inhibitors: (1) marked renal hypoperfusion, (2) vigorous diuretic therapy, (3) diabetes mellitus, and (4) intensity of hormonal inhibition within the kidney. This last risk factor may provide the basis for differentiating among enzyme-inhibitory drugs and suggests that renal insufficiency in low-output states may be minimized by the development of therapeutic agents that block hormonal synthesis selectively at sites that are critical to the disease process but spare the homeostatic tissue-based enzyme systems that exist within the kidney.

  1. Interest of analyses of heart rate variability in the prevention of fatigue states in senior runners.

    Science.gov (United States)

    Leti, Thomas; Bricout, Véronique A

    2013-01-01

    The use of heart rate variability (HRV) in the management of sport training is a practice which tends to spread, especially in order to prevent the occurrence of fatigue states. To estimate the HRV parameters obtained using a heart rate recording, according to different exercise impacts, and to make the link with the appearance of subjective fatigue. Ten senior runners, aged 51±5 years, were each monitored over a period of 12 weeks in different conditions: (i) after a resting period, (ii) after a day with training, (iii) after a day of competition and (iv) after a rest day. They also completed three questionnaires, to assess fatigue (SFMS), profile of mood states (POMS) and quality of sleep. The HRV indices (heart rate, LF (n.u.), HF (n.u.) and LF/HF) were significantly altered with the competitive impact, shifting toward a sympathetic predominance. After rest and recovery nights, the LF (n.u.) increased significantly with the competitive impact (62.1±15.2 and 66.9±11.6 vs. 76.0±10.7; p<0.05 respectively) whereas the HF (n.u.) decreased significantly (37.9±15.2 and 33.1±11.6 vs. 24.0±10.7; p<0.05 respectively). Positive correlations were found between fatigue and frequency domain indices and between fatigue and training impact. Autonomic nervous system modulation-fatigue relationships were significant, suggesting the potential use of HRV in follow-up and control of training. Furthermore, the addition of questionnaires constitutes complementary tools that allow to achieve a greater relevance and accuracy of the athletes' fitness and results. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Abnormal heart rate recovery and deficient chronotropic response after submaximal exercise in young Marfan syndrome patients.

    Science.gov (United States)

    Peres, Paulo; Carvalho, Antônio C; Perez, Ana Beatriz A; Medeiros, Wladimir M

    2016-10-01

    Marfan syndrome patients present important cardiac structural changes, ventricular dysfunction, and electrocardiographic changes. An abnormal heart rate response during or after exercise is an independent predictor of mortality and autonomic dysfunction. The aim of the present study was to compare heart rate recovery and chronotropic response obtained by cardiac reserve in patients with Marfan syndrome subjected to submaximal exercise. A total of 12 patients on β-blocker therapy and 13 off β-blocker therapy were compared with 12 healthy controls. They were subjected to submaximal exercise with lactate measurements. The heart rate recovery was obtained in the first minute of recovery and corrected for cardiac reserve and peak lactate concentration. Peak heart rate (141±16 versus 155±17 versus 174±8 bpm; p=0.001), heart rate reserve (58.7±9.4 versus 67.6±14.3 versus 82.6±4.8 bpm; p=0.001), heart rate recovery (22±6 versus 22±8 versus 34±9 bpm; p=0.001), and heart rate recovery/lactate (3±1 versus 3±1 versus 5±1 bpm/mmol/L; p=0.003) were different between Marfan groups and controls, respectively. All the patients with Marfan syndrome had heart rate recovery values below the mean observed in the control group. The absolute values of heart rate recovery were strongly correlated with the heart rate reserve (r=0.76; p=0.001). Marfan syndrome patients have reduced heart rate recovery and chronotropic deficit after submaximal exercise, and the chronotropic deficit is a strong determinant of heart rate recovery. These changes are suggestive of autonomic dysfunction.

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

    DEFF Research Database (Denmark)

    Alamili, M.; Rosenberg, J; Gögenur, I

    2015-01-01

    and parasympathetic activity can be estimated by measuring heart rate variability (HRV). Based on the intimate link between ANS and the inflammatory response, we hypothesized, that HRV changes seen during endotoxaemia would be different based on time of the day the endotoxaemia is initiated. We investigated day....../HF and mean heart rate significantly increased by endotoxaemia (Pheart rate (P

  4. Relationship between heart rate and quiescent interval of the cardiac cycle in children using MRI

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei [Texas Children' s Hospital, E. B. Singleton Department of Pediatric Radiology, Houston, TX (United States); Bogale, Saivivek [Baylor University Medical Center, Department of Radiology, Dallas, TX (United States); Golriz, Farahnaz [Baylor College of Medicine, Department of Radiology, Houston, TX (United States); Krishnamurthy, Rajesh [Nationwide Children' s Hospital, Department of Diagnostic Radiology, Columbus, OH (United States)

    2017-11-15

    Imaging the heart in children comes with the challenge of constant cardiac motion. A prospective electrocardiography-triggered CT scan allows for scanning during a predetermined phase of the cardiac cycle with least motion. This technique requires knowing the optimal quiescent intervals of cardiac cycles in a pediatric population. To evaluate high-temporal-resolution cine MRI of the heart in children to determine the relationship of heart rate to the optimal quiescent interval within the cardiac cycle. We included a total of 225 consecutive patients ages 0-18 years who had high-temporal-resolution cine steady-state free-precession sequence performed as part of a magnetic resonance imaging (MRI) or magnetic resonance angiography study of the heart. We determined the location and duration of the quiescent interval in systole and diastole for heart rates ranging 40-178 beats per minute (bpm). We performed the Wilcoxon signed rank test to compare the duration of quiescent interval in systole and diastole for each heart rate group. The duration of the quiescent interval at heart rates <80 bpm and >90 bpm was significantly longer in diastole and systole, respectively (P<.0001 for all ranges, except for 90-99 bpm [P=.02]). For heart rates 80-89 bpm, diastolic interval was longer than systolic interval, but the difference was not statistically significant (P=.06). We created a chart depicting optimal quiescent intervals across a range of heart rates that could be applied for prospective electrocardiography-triggered CT imaging of the heart. The optimal quiescent interval at heart rates <80 bpm is in diastole and at heart rates ≥90 bpm is in systole. The period of quiescence at heart rates 80-89 bpm is uniformly short in systole and diastole. (orig.)

  5. Kubios HRV--heart rate variability analysis software.

    Science.gov (United States)

    Tarvainen, Mika P; Niskanen, Juha-Pekka; Lipponen, Jukka A; Ranta-Aho, Perttu O; Karjalainen, Pasi A

    2014-01-01

    Kubios HRV is an advanced and easy to use software for heart rate variability (HRV) analysis. The software supports several input data formats for electrocardiogram (ECG) data and beat-to-beat RR interval data. It includes an adaptive QRS detection algorithm and tools for artifact correction, trend removal and analysis sample selection. The software computes all the commonly used time-domain and frequency-domain HRV parameters and several nonlinear parameters. There are several adjustable analysis settings through which the analysis methods can be optimized for different data. The ECG derived respiratory frequency is also computed, which is important for reliable interpretation of the analysis results. The analysis results can be saved as an ASCII text file (easy to import into MS Excel or SPSS), Matlab MAT-file, or as a PDF report. The software is easy to use through its compact graphical user interface. The software is available free of charge for Windows and Linux operating systems at http://kubios.uef.fi. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  6. Determining cardiac vagal threshold from short term heart rate complexity

    Directory of Open Access Journals (Sweden)

    Hamdan Rami Abou

    2016-09-01

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

  7. Heart rate variability is reduced during acute uncomplicated diverticulitis.

    Science.gov (United States)

    Huang, Chenxi; Alamili, Mahdi; Rosenberg, Jacob; Gögenur, Ismail

    2016-04-01

    The aim of the present study was to report the trajectory of heart rate variability (HRV) indices during a low-grade acute inflammation and their associations to biomarkers for infection. Twelve patients with uncomplicated acute diverticulitis completed this observational study, which composed of 3 sessions of continuous HRV recording from 9 PM to 8 AM during ongoing diverticulitis and at complete remission (baseline). The blood samples were collected at each study session measuring C-reactive protein (CRP) and leukocytes. This study showed that the trajectories of the HRV indices were decreased both in time and frequency domains during acute diverticulitis compared to baseline. In particular, the indices reflecting the balance of sympathetic and parasympathetic activities were affected: standard deviation of normal-to-normal beats (P = .003), low-frequency power (P diverticulitis suggesting inflammatory involvement in the observed HRV alterations. We found substantial HRV depression in relation to acute uncomplicated diverticulitis, and this was associated with the elevated CRP levels. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Digital Heart-Rate Variability Parameter Monitoring and Assessment ASIC.

    Science.gov (United States)

    Massagram, W; Hafner, N; Mingqi Chen; Macchiarulo, L; Lubecke, V M; Boric-Lubecke, O

    2010-02-01

    This paper describes experimental results for an application-specific integrated circuit (ASIC), designed for digital heart rate variability (HRV) parameter monitoring and assessment. This ASIC chip measures beat-to-beat (RR) intervals and stores HRV parameters into its internal memory in real time. A wide range of short-term and long-term ECG signals obtained from Physionet was used for testing. The system detects R peaks with millisecond accuracy, and stores up to 2 min of continuous RR interval data and up to 4 min of RR interval histogram. The prototype chip was fabricated in a 0.5 ¿m complementary metal-oxide semiconductor technology on a 3×3 mm(2) die area, with a measured dynamic power consumption of 10 ¿W and measured leakage current of 2.62 nA. The HRV monitoring system including this HRV ASIC, an analog-to-digital converter, and a low complexity microcontroller was estimated to consume 32.5 ¿V, which is seven times lower power than a stand-alone microcontroller performing the same functions. Compact size, low cost, and low power consumption make this chip suitable for a miniaturized portable HRV monitoring system.

  9. Heart Rate Variability Discriminates Competitive Levels in Professional Soccer Players.

    Science.gov (United States)

    Proietti, Riccardo; di Fronso, Selenia; Pereira, Lucas A; Bortoli, Laura; Robazza, Claudio; Nakamura, Fabio Y; Bertollo, Maurizio

    2017-06-01

    Heart rate variability (HRV) has been increasingly used to monitor team sports athletes. Besides the traditional time domain indices (i.e., the SD of successive RR intervals [SDNN] and the root mean square difference of successive normal RR intervals [RMSSD]), recently the use of the stress score (SS), which is an inverse function of the SD2 index derived from the Poincaré plot, and the sympathetic/parasympathetic ratio (S/PS) to monitor soccer players has been proposed. However, the reliability of these new indices and the ability of HRV to differentiate between soccer competitive levels are unknown. The aim of this study was to analyze the reliability of the different HRV-derived indices in professional soccer players during the competitive period and to compare HRV of professional soccer players from 3 teams of distinct competitive levels (i.e., Italian Second Division [2D], European League [EL], and Champions League [CL]). Fifty-four male professional soccer players from 3 different teams of 2 European countries (Italy and Germany) participated in the study. The intraclass correlation coefficient values of the HRV indices varied from 0.78 (very large) to 0.90 (near perfect). The coefficient of variation (CV) values for RMSSD and SDNN were all soccer players and is able to differentiate between international- and national-level players.

  10. Heart Rate Recovery after Cognitive Challenge is Preserved with Age

    Science.gov (United States)

    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.

    2010-01-01

    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

  11. Feature selection using genetic algorithms for fetal heart rate analysis

    International Nuclear Information System (INIS)

    Xu, Liang; Redman, Christopher W G; Georgieva, Antoniya; Payne, Stephen J

    2014-01-01

    The fetal heart rate (FHR) is monitored on a paper strip (cardiotocogram) during labour to assess fetal health. If necessary, clinicians can intervene and assist with a prompt delivery of the baby. Data-driven computerized FHR analysis could help clinicians in the decision-making process. However, selecting the best computerized FHR features that relate to labour outcome is a pressing research problem. The objective of this study is to apply genetic algorithms (GA) as a feature selection method to select the best feature subset from 64 FHR features and to integrate these best features to recognize unfavourable FHR patterns. The GA was trained on 404 cases and tested on 106 cases (both balanced datasets) using three classifiers, respectively. Regularization methods and backward selection were used to optimize the GA. Reasonable classification performance is shown on the testing set for the best feature subset (Cohen's kappa values of 0.45 to 0.49 using different classifiers). This is, to our knowledge, the first time that a feature selection method for FHR analysis has been developed on a database of this size. This study indicates that different FHR features, when integrated, can show good performance in predicting labour outcome. It also gives the importance of each feature, which will be a valuable reference point for further studies. (paper)

  12. Heart rate variability interventions for concussion and rehabilitation.

    Science.gov (United States)

    Conder, Robert L; Conder, Alanna A

    2014-01-01

    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 HRV implies cardiopathology, morbidity, reduced quality-of-life, and precipitous mortality. On the positive, optimal HRV 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 HRV 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.

  13. Heart rate never lies: interventional cardiologist and Braude's quote revised.

    Science.gov (United States)

    Cook, Stéphane; Stauffer, Jean-Christophe; Goy, Jean-Jacques; Graf, Denis; Puricel, Serban; Frobert, Aurélien; Muller, Olivier; Togni, Mario; Arroyo, Diego

    2016-01-01

    Interventional cardiologists may be immune to stress, allowing them to perform complex percutaneous interventions under pressure. To assess heart rate (HR) variations as a surrogate marker of stress of interventional cardiologists during percutaneous cardiac procedures and in every-day life. This is a single-centre observational study including a total of six male interventional cardiologists performing coronary interventions and pacemaker implantations. Participants were asked to record their HR with the Apple Watch Device during procedures, every-day life and control activities such as outpatient consultations, sport, marital conflicts and sexual intercourse. Average daily HR was 88±17 bpm. During work days, HR increased significantly during procedures (90±17 bpm) compared with days outside the cathlab (87±17 bpm, p=0.02). The average HR was higher during a regular week working (88±16 bpm) compared with weekends off (84±18 bpm, p=0.002). Complex cardiac procedures were associated with higher HR up to 122 bpm. Peak HR were higher during physical exertion. Of note, participants complained of hypersexuality and mania after night shifts. Work and especially percutaneous cardiac procedures increase HR independently of physical exertion suggesting that interventional cardiologists experience mental stress and emotions.

  14. Clinical Application of Heart Rate Variability after Acute Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Heikki Veli Huikuri

    2012-02-01

    Full Text Available AbstractHeart rate (HR variability has been extensively studied in patients surviving an acute myocardial infarction (AMI. The majority of studies have shown that patients with reduced or abnormal HR variability/turbulence have an increased risk of mortality within few years after an AMI. Various measures of HR dynamics, such as time-domain, spectral, and non-linear measures of HR variability, as well as HR turbulence, have been used in risk stratification of post-AMI patients. The prognostic power of various measures, except of those reflecting rapid R-R interval oscillations, has been almost identical, albeit some non-linear HR variability measures, such as short-term fractal scaling exponent, and HR turbulence, have provided somewhat better prognostic information than the others. Abnormal HR variability predicts both sudden and non-sudden cardiac death after AMI. Because of remodeling of the arrhythmia substrate after AMI, early measurement of HR variability to identify those at high risk should likely be repeated later in order to assess the risk of fatal arrhythmia events. Future randomized trials using HR variability/turbulence as one of the pre-defined inclusion criteria will show whether routine measurement of HR variability/turbulence will become a routine clinical tool for risk stratification of post-AMI patients.

  15. Body mass index is related to autonomic nervous system activity as measured by heart rate variability.

    Science.gov (United States)

    Molfino, A; Fiorentini, A; Tubani, L; Martuscelli, M; Rossi Fanelli, F; Laviano, A

    2009-10-01

    Autonomic nervous system activity is involved in body weight regulation. We assessed whether the body mass index (BMI) is related to the autonomic nervous system activity as assessed by heart rate variability (HRV). Twenty-five adult normotensive, euglycemic healthy males (M) and females (F) were studied (M/F=13/12). BMI was assessed in each individual. HRV was assessed and the domains of low frequencies (LF, index of the sympathetic modulation) and high frequencies (HF, index of the parasympathetic modulation) were measured. Data were statistically analyzed and are presented as mean+/-s.d. Mean BMI did not correlate with either HF or LF. It inversely related to HF (r=-0.50, P<0.01), whereas its relationship with LF was marginally significant (r=-0.39, P=0.05). The HF in individuals with BMI <20 kg/m(2) was significantly higher from those measured in the remaining subjects (P<0.05). The results support the role of parasympathetic activity in influencing BMI through likely modulation of body weight.

  16. Effects of exercise intensity and duration on nocturnal heart rate variability and sleep quality.

    Science.gov (United States)

    Myllymäki, Tero; Rusko, Heikki; Syväoja, Heidi; Juuti, Tanja; Kinnunen, Marja-Liisa; Kyröläinen, Heikki

    2012-03-01

    Acute physical exercise may affect cardiac autonomic modulation hours or even days during the recovery phase. Although sleep is an essential recovery period, the information on nocturnal autonomic modulation indicated by heart rate variability (HRV) after different exercises is mostly lacking. Therefore, this study investigated the effects of exercise intensity and duration on nocturnal HR, HRV, HR, and HRV-based relaxation, as well as on actigraphic and subjective sleep quality. Fourteen healthy male subjects (age 36 ± 4 years, maximal oxygen uptake 49 ± 4 ml/kg/min) performed five different running exercises on separate occasions starting at 6 p.m. with HR guidance at home. The effect of intensity was studied with 30 min of exercises at intensities corresponding to HR level at 45% (easy), 60% (moderate) and 75% (vigorous) of their maximal oxygen uptake. The effect of duration was studied with 30, 60, and 90 min of moderate exercises. Increased exercise intensity elevated nocturnal HR compared to control day (p exercises (p exercise day compared to control day (p exercise intensity nor duration had any impact on actigraphic or subjective sleep quality. The results suggest that increased exercise intensity and/or duration cause delayed recovery of nocturnal cardiac autonomic modulation, although long exercise duration was needed to induce changes in nocturnal HRV. Increased exercise intensity or duration does not seem to disrupt sleep quality.

  17. Wearable Sensing of In-Ear Pressure for Heart Rate Monitoring with a Piezoelectric Sensor

    Directory of Open Access Journals (Sweden)

    Jang-Ho Park

    2015-09-01

    Full Text Available In this study, we developed a novel heart rate (HR monitoring approach in which we measure the pressure variance of the surface of the ear canal. A scissor-shaped apparatus equipped with a piezoelectric film sensor and a hardware circuit module was designed for high wearability and to obtain stable measurement. In the proposed device, the film sensor converts in-ear pulse waves (EPW into electrical current, and the circuit module enhances the EPW and suppresses noise. A real-time algorithm embedded in the circuit module performs morphological conversions to make the EPW more distinct and knowledge-based rules are used to detect EPW peaks. In a clinical experiment conducted using a reference electrocardiogram (ECG device, EPW and ECG were concurrently recorded from 58 healthy subjects. The EPW intervals between successive peaks and their corresponding ECG intervals were then compared to each other. Promising results were obtained from the samples, specifically, a sensitivity of 97.25%, positive predictive value of 97.17%, and mean absolute difference of 0.62. Thus, highly accurate HR was obtained from in-ear pressure variance. Consequently, we believe that our proposed approach could be used to monitor vital signs and also utilized in diverse applications in the near future.

  18. N-terminal-pro-B-type natriuretic peptide during pharmacological heart rate reduction in hyperthyroidism

    DEFF Research Database (Denmark)

    Schultz, M; Kistorp, C; Corell, P

    2009-01-01

    of pharmacologically induced heart rate reduction in untreated hyperthyroidism. We designed a noncontrolled interventional study. Eighteen women with newly diagnosed hyperthyroidism were evaluated (including an echocardiography) before and after pharmacological heart rate reduction with 360 mg verapamil daily for 6......; resting heart rate [from mean 97 to 80 beats per min (17.5%), p...-index decreased from median 319 to 315 arbitrary units (p=0.039) and free triiodothyronine-index increased from 8.6 to 9.9 arbitrary units (p=0.010). No changes in echocardiographic parameters were observed. A decrease in resting heart rate in untreated hyperthyroidism due to verapamil treatment did not result...

  19. Sleep Apnoea Detection in Single Channel ECGs by Analyzing Heart Rate Dynamics

    National Research Council Canada - National Science Library

    Zywietz, C

    2001-01-01

    .... Our analysis is based on spectral components of heart rate variability. Frequency analysis was performed using Fourier and wavelet transformation with appropriate application of the Hilbert transform...

  20. Correlation of heart rate and radionuclide index of left ventricular contraction and relaxation

    International Nuclear Information System (INIS)

    Adachi, Haruhiko; Sugihara, Hiroki; Nakagawa, Hiroaki; Inagaki, Suetsugu; Kubota, Yasushi; Nakagawa, Masao

    1990-01-01

    Since the cardiac function indices derived from radionuclide ventriculography (RNV) are considered to depend on the heart rate, we studied the relationship between systolic or diastolic indices and heart rates in patients with normal RNV and devised a method of correcting these indices according to the heart rate. For the systolic indices, the heart rate showed significant correlation with ET (r=-0.640), PER (r=0.791) and TPE (r=-0.401) but not with EF, 1/3 EF, MNSER or 1/3 MNSER. For the diastolic indices, the heart rate correlated well with FT (r=-0.938), RFT (r=-0.736), SFT (r=-0.803), 1/3 FF (r=-0.758), PFR (r=0.759), 1/3 PFR (r=0.742) and TPF (r=-0.389) but not with AFT, 1/3 MNDFR or AFF. These results indicate that many systolic and diastolic indices derived from RNV are affected by the heart rate, So when cardiac function is evaluated with the use of radionuclide indices, those which are independent of the heart rate should be used, or they should be corrected for the heart rate. As a method of correction, we proposed a rotating method obtained by manipulation of the regression equation of heart rates and indices. This new method is certain and easier to use when the correcting equations are set into a computer program. (author)

  1. Changes in Heart Rate Variability after Coronary Artery Bypass Grafting and Clinical Importance of These Findings.

    Science.gov (United States)

    Lakusic, Nenad; Mahovic, Darija; Kruzliak, Peter; Cerkez Habek, Jasna; Novak, Miroslav; Cerovec, Dusko

    2015-01-01

    Heart rate variability is a physiological feature indicating the influence of the autonomic nervous system on the heart rate. Association of the reduced heart rate variability due to myocardial infarction and the increased postinfarction mortality was first described more than thirty years ago. Many studies have unequivocally demonstrated that coronary artery bypass grafting surgery generally leads to significant reduction in heart rate variability, which is even more pronounced than after myocardial infarction. Pathophysiologically, however, the mechanisms of heart rate variability reduction associated with acute myocardial infarction and coronary artery bypass grafting are different. Generally, heart rate variability gradually recovers to the preoperative values within six months of the procedure. Unlike the reduced heart rate variability in patients having sustained myocardial infarction, a finding of reduced heart rate variability after coronary artery bypass surgery is not considered relevant in predicting mortality. Current knowledge about changes in heart rate variability in coronary patients and clinical relevance of such a finding in patients undergoing coronary artery bypass grafting are presented.

  2. THE ANALYSIS OF HEART RATE VARIABILITY IN ELITE ATHLETES DURING NON STATION NARY PROCESSES

    Directory of Open Access Journals (Sweden)

    G. V. Korobeynikov

    2016-06-01

    Full Text Available The heart rate variability during non stationary processes in athletes was studied. The 29 elite athletes were examined. The parameters of scattergram for analysis of non stationnary processes of heart rate regulation were used. The results are shows about of tendency for decrease of periodic and non periodic variations of cardiac intervals depending from characters of reaction of heart rate. The obtained result showed the aging increasing of tension of autonomic regulation of heart rate of athletes as fatigue or non adequate performance.

  3. [Heart rate as a therapeutic target after acute coronary syndrome and in chronic coronary heart disease].

    Science.gov (United States)

    Ambrosetti, Marco; Scardina, Giuseppe; Favretto, Giuseppe; Temporelli, Pier Luigi; Faggiano, Pompilio Massimo; Greco, Cesare; Pedretti, Roberto Franco

    2017-03-01

    For patients with stable coronary artery disease (SCAD), either after hospitalization for acute cardiac events or in the chronic phase, comprehensive treatment programs should be devoted to: (i) reducing mortality and major adverse cardiovascular events, (ii) reducing the ischemic burden and related symptoms, and (iii) increasing exercise capacity and quality of life.Heart rate (HR) has demonstrated to have prognostic value and patients beyond the limit of 70 bpm display increased risk of all the above adverse outcomes, even after adjustment for parameters such as the extension of myocardial infarction and the presence of heart failure. It is well known that a sustained HR elevation may contribute to the pathogenesis of SCAD, being the likelihood of developing ischemia, plaque instability, trigger for arrhythmias, increased vascular oxidative stress, and endothelial dysfunction the mechanisms resulting in this effect. Moreover, high HR could promote chronotropic incompetence, leading to functional disability and reduced quality of life.Despite the strong relationship between HR and prognosis, there is heterogeneity among current guidelines in considering HR as a formal therapeutic target for secondary prevention in SCAD, as far as the cut-off limit. This expert opinion document considered major trials and observational registries in the modern treatment era with beta-blockers and ivabradine, suggesting that an adequate HR control could represent a target for (i), (ii), and (iii) therapeutic goals in SCAD patients with systolic dysfunction (with major evidence for reduced left ventricular ejection fraction SCAD patients with preserved left ventricular ejection fraction. The defined cut-off limit is 70 bpm. To date, there is room for improvement of HR control, since in contemporary SCAD patients HR values <70 bpm are present in less than half of cases, even in the vulnerable phase after an acute coronary syndrome.

  4. Effects of Exercise Training on Heart Rate Variability in Chagas Heart Disease

    Directory of Open Access Journals (Sweden)

    Bruno Ramos Nascimento

    2014-09-01

    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.

  5. Interaction between age and aerobic fitness in determining heart rate dynamics.

    Science.gov (United States)

    McNarry, M A; Lewis, M J

    2012-06-01

    Heart rate variability (HRV) and phase-rectified signal averaging (PRSA) estimates of heart rate dynamics are diminished in older people compared with younger people. However, it is not fully elucidated whether these differences are related to age per se or to the concomitant influence of aerobic fitness. Aerobic fitness (peak oxygen uptake, gas exchange threshold, oxygen uptake kinetics, exercise economy) was assessed in 70 healthy adults (41 male) aged 18-57 years. Participants also underwent a 24 h, ambulatory ECG for the derivation of HRV and PRSA variables. HRV was most sensitive to age and aerobic fitness when measured during the morning period (6 am-12 pm). HRV and PRSA were both diminished with age and were higher in aerobically superior participants. The decline in HRV with age was predominantly attributable to age itself (33%), with aerobic fitness representing an additional modulating factor. The present study also provides tentative evidence that assessment of the influence of aerobic fitness should not rely on [Formula: see text]O(2peak) alone. These findings demonstrate that age per se is an important factor in determining HRV. However, given the clinical importance of diminished HRV and the immutable nature of aging, the potential significance of physical activity/training to enhance cardiac regulatory function should not be underestimated.

  6. Heart rate during conflicts predicts post-conflict stress-related behavior in greylag geese.

    Directory of Open Access Journals (Sweden)

    Claudia A F Wascher

    Full Text Available BACKGROUND: Social stressors are known to be among the most potent stressors in group-living animals. This is not only manifested in individual physiology (heart rate, glucocorticoids, but also in how individuals behave directly after a conflict. Certain 'stress-related behaviors' such as autopreening, body shaking, scratching and vigilance have been suggested to indicate an individual's emotional state. Such behaviors may also alleviate stress, but the behavioral context and physiological basis of those behaviors is still poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: We recorded beat-to-beat heart rates (HR of 22 greylag geese in response to agonistic encounters using fully implanted sensor-transmitter packages. Additionally, for 143 major events we analyzed the behavior shown by our focal animals in the first two minutes after an interaction. Our results show that the HR during encounters and characteristics of the interaction predicted the frequency and duration of behaviors shown after a conflict. CONCLUSIONS/SIGNIFICANCE: To our knowledge this is the first study to quantify the physiological and behavioral responses to single agonistic encounters and to link this to post conflict behavior. Our results demonstrate that 'stress-related behaviors' are flexibly modulated by the characteristics of the preceding aggressive interaction and reflect the individual's emotional strain, which is linked to autonomic arousal. We found no support for the stress-alleviating hypothesis, but we propose that stress-related behaviors may play a role in communication with other group members, particularly with pair-partners.

  7. Heart rate during conflicts predicts post-conflict stress-related behavior in greylag geese.

    Science.gov (United States)

    Wascher, Claudia A F; Fraser, Orlaith N; Kotrschal, Kurt

    2010-12-20

    Social stressors are known to be among the most potent stressors in group-living animals. This is not only manifested in individual physiology (heart rate, glucocorticoids), but also in how individuals behave directly after a conflict. Certain 'stress-related behaviors' such as autopreening, body shaking, scratching and vigilance have been suggested to indicate an individual's emotional state. Such behaviors may also alleviate stress, but the behavioral context and physiological basis of those behaviors is still poorly understood. We recorded beat-to-beat heart rates (HR) of 22 greylag geese in response to agonistic encounters using fully implanted sensor-transmitter packages. Additionally, for 143 major events we analyzed the behavior shown by our focal animals in the first two minutes after an interaction. Our results show that the HR during encounters and characteristics of the interaction predicted the frequency and duration of behaviors shown after a conflict. To our knowledge this is the first study to quantify the physiological and behavioral responses to single agonistic encounters and to link this to post conflict behavior. Our results demonstrate that 'stress-related behaviors' are flexibly modulated by the characteristics of the preceding aggressive interaction and reflect the individual's emotional strain, which is linked to autonomic arousal. We found no support for the stress-alleviating hypothesis, but we propose that stress-related behaviors may play a role in communication with other group members, particularly with pair-partners.

  8. Interaction between age and aerobic fitness in determining heart rate dynamics

    International Nuclear Information System (INIS)

    McNarry, M A; Lewis, M J

    2012-01-01

    Heart rate variability (HRV) and phase-rectified signal averaging (PRSA) estimates of heart rate dynamics are diminished in older people compared with younger people. However, it is not fully elucidated whether these differences are related to age per se or to the concomitant influence of aerobic fitness. Aerobic fitness (peak oxygen uptake, gas exchange threshold, oxygen uptake kinetics, exercise economy) was assessed in 70 healthy adults (41 male) aged 18–57 years. Participants also underwent a 24 h, ambulatory ECG for the derivation of HRV and PRSA variables. HRV was most sensitive to age and aerobic fitness when measured during the morning period (6 am–12 pm). HRV and PRSA were both diminished with age and were higher in aerobically superior participants. The decline in HRV with age was predominantly attributable to age itself (33%), with aerobic fitness representing an additional modulating factor. The present study also provides tentative evidence that assessment of the influence of aerobic fitness should not rely on .VO 2peak alone. These findings demonstrate that age per se is an important factor in determining HRV. However, given the clinical importance of diminished HRV and the immutable nature of aging, the potential significance of physical activity/training to enhance cardiac regulatory function should not be underestimated. (paper)

  9. Do physiological and pathological stresses produce different changes in heart rate variability?

    Directory of Open Access Journals (Sweden)

    Andrea eBravi

    2013-07-01

    Full Text Available Although physiological (e.g. exercise and pathological (e.g. infection stress affecting the cardiovascular system have both been documented to be associated with a reduction in overall heart rate variability (HRV, it remains unclear if loss of HRV is ubiquitously similar across different domains of variability analysis or if distinct patterns of altered HRV exist depending on the stressor. Using Continuous Individualized Multiorgan Variability Analysis (CIMVATM software, heart rate (HR and four selected measures of variability were measured over time (windowed analysis from two datasets, a set (n=13 of patients who developed systemic infection (i.e. sepsis after bone marrow transplant, and a matched set of healthy subjects undergoing physical exercise under controlled conditions. HR and the four HRV measures showed similar trends in both sepsis and exercise. The comparison through Wilcoxon sign-rank test of the levels of variability at baseline and during the stress (i.e. exercise or after days of sepsis development showed similar changes, except for LF/HF, ratio of power at low and high frequencies (associated with sympathovagal modulation, which was affected by exercise but did not show any change during sepsis. Furthermore, HRV measures during sepsis showed a lower level of correlation with each other, as compared to HRV during exercise. In conclusion, this exploratory study highlights similar responses during both exercise and infection, with differences in terms of correlation and inter-subject fluctuations, whose physiologic significance merits further investigation.

  10. Breathing exercise combined with cognitive behavioural intervention improves sleep quality and heart rate variability in major depression.

    Science.gov (United States)

    Chien, Hui-Ching; Chung, Yu-Chu; Yeh, Mei-Ling; Lee, Jia-Fu

    2015-11-01

    , participants could modulate their heart rate variability and share feeling about good sleep as well relaxation. © 2015 John Wiley & Sons Ltd.

  11. The effect of metaprolol alone and metaprolol plus bromazepam on heart rate and heart rate variability during multislice computed tomography angiography

    International Nuclear Information System (INIS)

    Tuyyab, F.; Naeem, M.Y.; Maken, G.R.; Najfi, M.H.; Hassan, F.

    2012-01-01

    Objective: The purpose of this study was to determine the effect of metaprolol alone and metaprolol plus bromazepam on heart rate and heart rate variability during multi slice computed tomography (MSCT) angiography. Methodology: This was a Double blind randomized controlled trial was conducted at AFIC/NIHD, Rawalpindi, from May 2011 to November 2011. Patients undergoing first MSCT angiography meeting inclusion criteria with heart rates (HR) more than 80 beats/min were included. Patients were randomized in to two groups using random numbers table. Group 1 was administered metaprolol plus placebo while group 2 was administered metaprolol plus bromazepam one hour before the scan. Both groups had scans under strictly similar conditions. HR before and during scan along with heart rate variability (HRV) were recorded. Results: A total of 80 patients were included. Patients mean age was 49 + 13, 57 % were males while 43 % were females. Risk factor profile was similar in both groups. HR reduction in group 1 was 15+ 6.0 and in group 2, was 21+9.0 (p= 0.002). HRV in group 1 was 3.9 + 1.32 and in group 2 was 2.3 + 1.0 (p= 0.003). Group 2 had significantly lower HR and significantly less HRV as compared with group 1. Conclusion: Combination of bromazepam and metaprolol results in significant and further reduction in heart rate and heart rate variability than metaprolol alone. Both drugs can be used together for a better control of heart rate and heart rate variability during MSCT angiography for improving the quality of images. (author)

  12. Vagally-Mediated Heart Rate Variability and Indices of Wellbeing: Results of a Nationally Representative Study

    Science.gov (United States)

    Sloan, Richard P; Schwarz, Emilie; McKinley, Paula S; Weinstein, Maxine; Love, Gayle; Ryff, Carol; Mroczek, Daniel; Choo, Tse; Lee, Seonjoo; Seeman, Teresa

    2016-01-01

    Objective High frequency (HF) heart rate variability (HRV) has long been accepted as an index of cardiac vagal control. Recent studies report relationships between HF-HRV and indices of positive and negative affect, personality traits and wellbeing but these studies generally are based on small and selective samples. Method These relationships were examined using data from 967 participants in the second Midlife in the US (MIDUS II) study. Participants completed survey questionnaires on wellbeing and affect. HF-HRV was measured at rest. A hierarchical series of regression analyses examined relationships between these various indices and HF-HRV before and after adjustment for relevant demographic and biomedical factors. Results Significant inverse relationships were found only between indices of negative affect and HF-HRV. Relationships between indices of psychological and hedonic wellbeing and positive affect failed to reach significance. Conclusions These findings raise questions about relationships between cardiac parasympathetic modulation, emotion regulation, and indices of wellbeing. PMID:27570892

  13. Automatic stress-relieving music recommendation system based on photoplethysmography-derived heart rate variability analysis.

    Science.gov (United States)

    Shin, Il-Hyung; Cha, Jaepyeong; Cheon, Gyeong Woo; Lee, Choonghee; Lee, Seung Yup; Yoon, Hyung-Jin; Kim, Hee Chan

    2014-01-01

    This paper presents an automatic stress-relieving music recommendation system (ASMRS) for individual music listeners. The ASMRS uses a portable, wireless photoplethysmography module with a finger-type sensor, and a program that translates heartbeat signals from the sensor to the stress index. The sympathovagal balance index (SVI) was calculated from heart rate variability to assess the user's stress levels while listening to music. Twenty-two healthy volunteers participated in the experiment. The results have shown that the participants' SVI values are highly correlated with their prespecified music preferences. The sensitivity and specificity of the favorable music classification also improved as the number of music repetitions increased to 20 times. Based on the SVI values, the system automatically recommends favorable music lists to relieve stress for individuals.

  14. Heart rate variability in male shift workers in automobile manufacturing factories in South Korea.

    Science.gov (United States)

    Lee, Sangyoon; Kim, Ho; Kim, Dae-Hwan; Yum, Myunggul; Son, Mia

    2015-10-01

    The aim of this study was to determine the effect of circadian rhythm disruption on cardiovascular autonomic regulation by examining potential differences in heart rate variability (HRV) between day- and night-shift workers. The study population consisted of 162 workers who worked both day and night shifts in two automobile manufacturing companies who underwent ambulatory 24-h electrocardiogram recording and completed questionnaires and sleep diaries. Both time and frequency domain indices of HRV were compared. HRV parameters (mean RR, SDNN, RMSSD, pNN50, TP, HF, LF, LF/HF ratio) reflecting sympathetic and parasympathetic modulation varied less with activity in night-shift workers. Circadian rhythm-mediated changes in autonomic regulation of the cardiovascular system were blunted in night-shift workers, which could contribute to an increased risk for cardiovascular disease in overnight workers.

  15. Estimating respiratory and heart rates from the correntropy spectral density of the photoplethysmogram.

    Directory of Open Access Journals (Sweden)

    Ainara Garde

    Full Text Available The photoplethysmogram (PPG obtained from pulse oximetry measures local variations of blood volume in tissues, reflecting the peripheral pulse modulated by heart activity, respiration and other physiological effects. We propose an algorithm based on the correntropy spectral density (CSD as a novel way to estimate respiratory rate (RR and heart rate (HR from the PPG. Time-varying CSD, a technique particularly well-suited for modulated signal patterns, is applied to the PPG. The respiratory and cardiac frequency peaks detected at extended respiratory (8 to 60 breaths/min and cardiac (30 to 180 beats/min frequency bands provide RR and HR estimations. The CSD-based algorithm was tested against the Capnobase benchmark dataset, a dataset from 42 subjects containing PPG and capnometric signals and expert labeled reference RR and HR. The RR and HR estimation accuracy was assessed using the unnormalized root mean square (RMS error. We investigated two window sizes (60 and 120 s on the Capnobase calibration dataset to explore the time resolution of the CSD-based algorithm. A longer window decreases the RR error, for 120-s windows, the median RMS error (quartiles obtained for RR was 0.95 (0.27, 6.20 breaths/min and for HR was 0.76 (0.34, 1.45 beats/min. Our experiments show that in addition to a high degree of accuracy and robustness, the CSD facilitates simultaneous and efficient estimation of RR and HR. Providing RR every minute, expands the functionality of pulse oximeters and provides additional diagnostic power to this non-invasive monitoring tool.

  16. Estimating respiratory and heart rates from the correntropy spectral density of the photoplethysmogram.

    Science.gov (United States)

    Garde, Ainara; Karlen, Walter; Ansermino, J Mark; Dumont, Guy A

    2014-01-01

    The photoplethysmogram (PPG) obtained from pulse oximetry measures local variations of blood volume in tissues, reflecting the peripheral pulse modulated by heart activity, respiration and other physiological effects. We propose an algorithm based on the correntropy spectral density (CSD) as a novel way to estimate respiratory rate (RR) and heart rate (HR) from the PPG. Time-varying CSD, a technique particularly well-suited for modulated signal patterns, is applied to the PPG. The respiratory and cardiac frequency peaks detected at extended respiratory (8 to 60 breaths/min) and cardiac (30 to 180 beats/min) frequency bands provide RR and HR estimations. The CSD-based algorithm was tested against the Capnobase benchmark dataset, a dataset from 42 subjects containing PPG and capnometric signals and expert labeled reference RR and HR. The RR and HR estimation accuracy was assessed using the unnormalized root mean square (RMS) error. We investigated two window sizes (60 and 120 s) on the Capnobase calibration dataset to explore the time resolution of the CSD-based algorithm. A longer window decreases the RR error, for 120-s windows, the median RMS error (quartiles) obtained for RR was 0.95 (0.27, 6.20) breaths/min and for HR was 0.76 (0.34, 1.45) beats/min. Our experiments show that in addition to a high degree of accuracy and robustness, the CSD facilitates simultaneous and efficient estimation of RR and HR. Providing RR every minute, expands the functionality of pulse oximeters and provides additional diagnostic power to this non-invasive monitoring tool.

  17. Discovery of novel heart rate-associated loci using the Exome Chip

    Science.gov (United States)

    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.; Müller-Nurasyid, Martina; Lin, Honghuang; Mei, Hao; Smith, Albert V.; Lyytikäinen, 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, Renée; 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; Kähönen, Mika; Kanters, Jørgen 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.; Orrú, 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, André; Vaartjes, Ilonca; Hoes, Arno W.; van der Meer, Peter; Völker, Uwe; Waldenberger, Melanie; Xie, Zhijun; Zoledziewska, Magdalena; Tinker, Andrew; Polasek, Ozren; Rosand, Jonathan; Jamshidi, Yalda; van Duijn, Cornelia M.; Zeggini, Eleftheria; Jukema, J. Wouter; Asselbergs, Folkert W.; Samani, Nilesh J.; Lehtimäki, Terho; Gudnason, Vilmundur; Wilson, James; Lubitz, Steven A.; Kääb, Stefan; Sotoodehnia, Nona; Caulfield, Mark J.; Palmer, Colin N. A.; Sanna, Serena; Mook-Kanamori, Dennis O.; Deloukas, Panos; Pedersen, Oluf; Rotter, Jerome I.; Dörr, Marcus; O'Donnell, Chris J.; Hayward, Caroline; Arking, Dan E.; Kooperberg, Charles; van der Harst, Pim; Eijgelsheim, Mark; Stricker, Bruno H.; Munroe, Patricia B.

    2017-01-01

    Abstract 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 discover new genetic loci associated with heart rate from Exome Chip meta-analyses. Heart rate was measured from either elecrtrocardiograms or pulse recordings. We meta-analysed heart rate association results from 104 452 European-ancestry individuals from 30 cohorts, genotyped using the Exome Chip. Twenty-four variants were selected for follow-up in an independent dataset (UK Biobank, N = 134 251). Conditional and gene-based testing was undertaken, and variants were investigated with bioinformatics methods. We discovered five novel heart rate loci, and one new independent low-frequency non-synonymous variant in an established heart rate locus (KIAA1755). Lead variants in four of the novel loci are non-synonymous variants in the genes C10orf71, DALDR3, TESK2 and SEC31B. The variant at SEC31B is significantly associated with SEC31B expression in heart and tibial nerve tissue. Further candidate genes were detected from long-range regulatory chromatin interactions in heart tissue (SCD, SLF2 and MAPK8). We observed significant enrichment in DNase I hypersensitive sites in fetal heart and lung. Moreover, enrichment was seen for the first time in human neuronal progenitor cells (derived from embryonic stem cells) and fetal muscle samples by including our novel variants. Our findings advance the knowledge of the genetic architecture of heart rate, and indicate new candidate genes for follow-up functional studies. PMID:28379579

  18. Modulation of cGMP in Heart Failure

    Science.gov (United States)

    Boerrigter, Guido; Lapp, Harald; Burnett, John C.

    2009-01-01

    Heart failure (HF) is a common disease that continues to be associated with high morbidity and mortality warranting novel therapeutic strategies. Cyclic guanosine monophosphate (cGMP) is the second messenger of several important signaling pathways based on distinct guanylate cyclases (GCs) in the cardiovascular system. Both the nitric oxide/soluble GC (NO/sGC) as well as the natriuretic peptide/GC-A (NP/GC-A) systems are disordered in HF, providing a rationale for their therapeutic augmentation. Soluble GC activation with conventional nitrovasodilators has been used for more than a century but is associated with cGMP-independent actions and the development of tolerance, actions which novel NO-independent sGC activators now in clinical development lack. Activation of GC-A by administration of naturally occurring or designer natriuretic peptides is an emerging field, as is the inhibition of enzymes that degrade endogenous NPs. Finally, inhibition of cGMP-degrading phosphodiesterases, particularly phosphodiesterase 5 provides an additional strategy to augment cGMP-signaling. PMID:19089342

  19. Heart rate recovery in elite Spanish male athletes.

    Science.gov (United States)

    Peinado, A B; Benito, P J; Barriopedro, M; Lorenzo, I; Maffulli, N; Calderón, F J

    2014-06-01

    During postexercise recovery, heart rate (HR) initially falls rapidly, followed by a period of slower decrease, until resting values are reached. The aim of the present work was to examine the differences in the recovery heart rate (RHR) between athletes engaged in static and dynamic sports. The study subjects were 294 federated sportsmen competing at the national and international level in sports classified using the criteria of Mitchell et al. as either prevalently static (N.=89) or prevalently dynamic (N.=205). Within the dynamic group, the subjects who practised the most dynamic sports were assigned to further subgroups: triathlon (N.=20), long distance running (N.=58), cycling (N.=28) and swimming (N.=12). All athletes were subjected to a maximum exertion stress test and their HR recorded at 1, 2, 3 and 4 min (RHR1,2,3,4) into the HR recovery period. The following indices of recovery (IR) were then calculated: IR1=(HRpeak-RHR1,2,3,4)/(HRmax-HRrest)*100, IR2=(HRpeak-RHR1,2,3,4)/(HRmax/HRpeak), and IR3=HRpeak-RHR1,2,3,4. The differences in the RHR and IR for the static and dynamic groups were examined using two way ANOVA. The RHR at minutes 2 (138.7±15.2 vs. 134.8±14.4 beats·min⁻¹) and 3 (128.5±15.2 vs. 123.3±14.4 beats·min⁻¹) were significantly higher for the static group (Group S) than the dynamic group (Group D), respectively. Significant differences were seen between Group D and S with respect to IR1 at minutes 1 (26.4±8.7 vs. 24.8±8.4%), 2 (43.8±8.1 vs. 41.5±7.8%), 3 (52.1±8.3 vs. 49.1±8%) and 4 (56.8±8.6 vs. 55.4±7.4%) of recovery. For IR2, significant differences were seen between the same groups at minutes 2 (59.7±12.5 vs. 55.9±10.8 beats·min⁻¹) and 3 (71.0±13.5 vs. 66.1±11.4 beats·min⁻¹) of recovery. Finally, for IR3, the only significant difference between Group D and S was recorded at minute 3 of recovery (72.2±12.5 vs. 66.2±11.5 beats·min⁻¹). This work provides information on RHR of a large population of elite

  20. Association of blood pressure and heart rate response during exercise with cardiovascular events in the Heart and Soul Study.

    Science.gov (United States)

    Habibzadeh, Mohammad R; Farzaneh-Far, Ramin; Sarna, Punit; Na, Beeya; Schiller, Nelson B; Whooley, Mary A

    2010-11-01

    We sought to evaluate the association of blood pressure and heart rate response during exercise with myocardial infarction (MI), heart failure, stroke, transient ischemic attack (TIA) and death in ambulatory adults with coronary artery disease. A study population of 937 patients with stable coronary artery disease underwent treadmill exercise stress testing and was followed for 5 years. Participants were divided into quartiles based on peak SBP change, peak SBP and heart rate. We used multivariable Cox proportional hazards models to evaluate the association of change in SBP and heart rate with subsequent cardiovascular events. The participants with SBP increases in the highest quartile had a decreased rate of hospitalization for heart failure [hazard ratio 0.38, 95% confidence interval (CI), 0.21-0.7; P = 0.002], MI (hazard ratio 0.3, 95% CI 0.15-0.58; P = 0.0004), stroke or TIA (hazard ratio 0.39, 95% CI 0.15-0.98; P = 0.04), and all cause mortality (hazard ratio 0.5, 95% CI 0.33-0.76; P = 0.001). After adjusting for age, history of MI and HTN, use of β blockers, statins and calcium channel blockers, resting heart rate, and SBP, participants with SBP change in the highest quartile remained at lowest risk of MI (hazard ratio 0.31, 95% CI 0.15-0.66, P = 0.002), hospitalization for heart failure (hazard ratio 0.46, 95% CI 0.22-0.97, P = 0.04) and death (hazard ratio 0.52, 95% CI 0.32-0.86, P = 0.01). This association was largely explained by greater exercise capacity in those with the highest SBP change. Change in heart rate had a similar association with cardiovascular events. In ambulatory patients with coronary artery disease, the group with the greatest blood pressure and heart rate increase had the lowest risk of MI, heart failure, stroke or TIA and death. These findings support the notion that a robust blood pressure response predicts favorable outcomes.

  1. VASCULAR REMODELING AND HEART RATE VARIABILITY IN DIFFERENT ANTIHYPERTENSIVE THERAPIES

    Directory of Open Access Journals (Sweden)

    E. D. Golovanova

    2008-01-01

    Full Text Available Aim. To study the effect of the long-term antihypertensive monotherapy with indapamide (Arifon Retard, 1,5 mg/d, metoprolol tartrate (Egilok Retard, 50 mg/d and combined therapy with indapamide and perindopril (Noliprel Forte, 1 tab/d: perindopril 4 mg and indapamide 1,25 mg on pulse wave velocity (PWV, cardio-ankle vascular index (CAVI and the sympathetic system activity.Material and methods. 88 patients, aged 30-59 y.o. (32 normotensive patients, 56 with arterial hypertension [HT] of 1-2 grades were examined. Biological age (BA was determined by the linear regression and the vascular wall age (VWA was estimated with the use of volume sphygmography (“VaSera-1000”, “Fucuda Denshi”, Japan. 39 patients with HT were randomized into 3 parallel groups with studied therapies lasted for 6 months. PWV, CAVI of the vessels of elastic, muscular and mixed types, blood pressure, measured in upper and lower extremities and heart rate variability (HRV were determined before and at the end of the therapies.Results. BA and VWA were elevated in all of patients with HT as compared with normotensive patients. The reduction in PWV and CAVI of the vessels of elastic and mixed types, HRV increase were found in patients with Arifon Retard monotherapy. Monotherapy with metoprolol significantly improved HVR without any influence on the vascular remodeling. Noliprel Forte significantly decreased in blood pressure in the upper and lower extremities, PWV and CAVI of the vessels of all types, decreased in VWA and increased in parasympathetic drive.Conclusion. Long-term therapy with Arifon Retard and Noliprel Forte resulted in decrease in vascular remodeling and increase in HRV simultaneously with significant antihypertensive effect in patients with HT. Metoprolol low doses therapy resulted in normalization of autonomic drive independently on antihypertensive action.

  2. Heart rate variability (HRV): an indicator of stress

    Science.gov (United States)

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

    2014-05-01

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

  3. Heart Rate Response of Professional Musicians When Playing Music.

    Science.gov (United States)

    Vellers, Heather L; Irwin, Conor; Lightfoot, J T

    2015-06-01

    The primary aim was to determine the level of physiological stress evoked while playing music in a standing position as indicated by heart rate (HR) response. A secondary aim was to analyze the effect of music genre (classic rock, western, contemporary Christian, and metal rock) on the relative HR response. Lastly, we considered potential physiological initiators of the music-playing-induced HR response. HR response was monitored in 27 professional musicians (3 women, 24 men) between the ages of 21 and 67 yrs old during rehearsal and public performances. The percent maximal HR (%MHR) evoked was determined by taking a percentage of the age-predicted maximal HR for each musician and comparing the average %MHR in each genre during public and rehearsal events. The role of the potential initiators of these responses (e.g., number of years playing in public, event type, instrument type, tempo, etc.) was determined using multiple regression analyses. The overall average %MHR responses were 52 ± 5% and 59 ± 5% during rehearsal and public performances, respectively, with genre type having a significant effect on the HR response (p=0.01). Body mass index and tempo were each found to be significant contributors to the HR response while playing music (r²=0.506, p=0.001). Playing music professionally evokes considerable increases in HR response, with music genre influencing the level of the physiological response. We concluded that 50% of the HR response while playing music was associated with body mass index, music tempo, and instrument type.

  4. Estimating mental fatigue based on electroencephalogram and heart rate variability

    Science.gov (United States)

    Zhang, Chong; Yu, Xiaolin

    2010-01-01

    The effects of long term mental arithmetic task on psychology are investigated by subjective self-reporting measures and action performance test. Based on electroencephalogram (EEG) and heart rate variability (HRV), the impacts of prolonged cognitive activity on central nervous system and autonomic nervous system are observed and analyzed. Wavelet packet parameters of EEG and power spectral indices of HRV are combined to estimate the change of mental fatigue. Then wavelet packet parameters of EEG which change significantly are extracted as the features of brain activity in different mental fatigue state, support vector machine (SVM) algorithm is applied to differentiate two mental fatigue states. The experimental results show that long term mental arithmetic task induces the mental fatigue. The wavelet packet parameters of EEG and power spectral indices of HRV are strongly correlated with mental fatigue. The predominant activity of autonomic nervous system of subjects turns to the sympathetic activity from parasympathetic activity after the task. Moreover, the slow waves of EEG increase, the fast waves of EEG and the degree of disorder of brain decrease compared with the pre-task. The SVM algorithm can effectively differentiate two mental fatigue states, which achieves the maximum classification accuracy (91%). The SVM algorithm could be a promising tool for the evaluation of mental fatigue. Fatigue, especially mental fatigue, is a common phenomenon in modern life, is a persistent occupational hazard for professional. Mental fatigue is usually accompanied with a sense of weariness, reduced alertness, and reduced mental performance, which would lead the accidents in life, decrease productivity in workplace and harm the health. Therefore, the evaluation of mental fatigue is important for the occupational risk protection, productivity, and occupational health.

  5. Interpreting category II fetal heart rate tracings: does meconium matter?

    Science.gov (United States)

    Frey, Heather A; Tuuli, Methodius G; Shanks, Anthony L; Macones, George A; Cahill, Alison G

    2014-12-01

    Category II fetal heart rate (FHR) tracings are considered indeterminate; thus, improved risk stratification of category II FHR tracings is needed. We estimated whether the presence of meconium increased the risk of adverse neonatal outcomes. This study was conducted within a prospective cohort of 5000 women with singleton pregnancies who were admitted in labor at term. Pregnancies with category II FHR in the 60 minutes before delivery were included. FHR data were extracted by trained nurses who were blinded to clinical outcome. The exposure was the presence of meconium. The primary outcome was a composite neonatal morbidity defined as ≥1 of the following: neonatal death, neurologic morbidity, respiratory morbidity, hypotension that required treatment, and sepsis. Secondary outcomes were nursery admission, cord pH, 5-minute Apgar score, and components of the composite. Logistic regression was used to adjust for confounders. Of the 3257 women with category II FHR tracings, 693 women (21.3%) had meconium, and 2564 women (78.7%) did not. Meconium was associated with higher risk of the composite morbidity (adjusted odds ratio, 2.49; 95% confidence interval, 1.78-3.48) and increased risks of the secondary outcomes. The associations remained significant when infants with meconium aspiration syndrome were excluded. Thick meconium was associated significantly with the composite morbidity. The presence of meconium is associated with an increased risk of neonatal morbidity in women with category II FHR pattern. This clinical factor may assist clinicians in managing category II FHR patterns in labor. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Heart Rate Variability in Men with Erectile dysfunction

    Directory of Open Access Journals (Sweden)

    Ji Yong Lee

    2011-06-01

    Full Text Available Purpose The objective of this study is to investigate alteration of autonomic nervous system (ANS activity in patients suffering from erectile dysfunction (ED by comparing parameters of heart rate variability (HRV between men with ED and healthy subjects. Methods A retrospective review was performed on 40 ED patients (mean age, 46.0±8.49 years without any disease and 180 healthy control people (mean age, 44.4±7.83 years without ED in our institution from June 2008 to July 2010. And electrocardiographic signals were obtained to measure HRV parameters for both patients and controls in a resting state. Results For the time domain analysis, square root of the mean differences between successive RR intervals (RMSSD representing parasympathetic activity was lower in patients than controls although P-value was not statistically significant (P=0.060. For the frequency domain analysis, high frequency (HF representing parasympathetic activity was lower in patients than controls (P=0.232 and low frequency (LF representing mainly sympathetic activity was higher in patients than controls (P=0.416. Lastly, LF/HF ratio reflecting sympathetic/parasympathetic activity ratio was statistically higher in patients than controls (P=0.027. Conclusions Patients with ED exhibited different HRV parameters compared with normal controls. This suggests that the patients with ED may have some kind of imbalance in the ANS and it may be possible that general imbalance of the ANS is one of the causes of ED. Thus, HRV analysis may give valuable diagnostic information and serve as a rapid screening tool to evaluate altered ANS activity in patients with ED.

  7. Acute effects of flexible pole exercise on heart rate dynamics.

    Science.gov (United States)

    de Oliveira, Letícia Santana; Moreira, Patrícia S; Antonio, Ana M; Cardoso, Marco A; de Abreu, Luiz Carlos; Navega, Marcelo T; Raimundo, Rodrigo D; Valenti, Vitor E

    2015-01-01

    Exercise with flexible poles provides fast eccentric and concentric muscle contractions. Although the literature reports significant muscle chain activity during this exercise, it is not clear if a single bout of exercise induces cardiac changes. In this study we assessed the acute effects of flexible pole exercise on cardiac autonomic regulation. The study was performed on 22 women between 18 and 26 years old. We assessed heart rate variability (HRV) in the time (SDNN, RMSSD and pNN50) and frequency (HF, LF and LF/HF ratio) domains and geometric indices of HRV (RRTri, TINN, SD1, SD2 and SD1/SD2 ratio). The subjects remained at rest for 10 min and then performed the exercises with the flexible poles. Immediately after the exercise protocol, the volunteers remained seated at rest for 60 min and HRV was analyzed. We observed no significant changes in time domain (SDNN: p=0.72; RMSSD: p=0.94 and pNN50: p=0.92) or frequency domain indices (LF [nu]: p=0.98; LF [ms(2)]: p=0.72; HF [nu]: p=0.98; HF [ms(2)]: p=0.82 and LF/HF ratio: p=0.7) or in geometric indices (RRTri: p=0.54; TINN: p=0.77; SD1: p=0.94; SD2: p=0.67 and SD/SD2: p=0.42) before and after a single bout of flexible pole exercise. A single bout of flexible pole exercise did not induce significant changes in cardiac autonomic regulation in healthy women. Copyright © 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  8. Heart rates and swim speeds of emperor penguins diving under sea ice.

    Science.gov (United States)

    Kooyman, G L; Ponganis, P J; Castellini, M A; Ponganis, E P; Ponganis, K V; Thorson, P H; Eckert, S A; LeMaho, Y

    1992-04-01

    Heart rate during overnight rest and while diving were recorded from five emperor penguins with a microprocessor-controlled submersible recorder. Heart rate, cardiac output and stroke volume were also measured in two resting emperor penguins using standard electrocardiography and thermodilution measurements. Swim velocities from eight birds were obtained with the submersible recorder. The resting average of the mean heart rates was 72 beats min-1. Diving heart rates were about 15% lower than resting rates. Cardiac outputs of 1.9-2.9 ml kg-1 s-1 and stroke volumes of 1.6-2.7 ml kg-1 were similar to values recorded from mammals of the same body mass. Swim velocities averaged 3 m s-1. The swim speeds and heart rates suggest that muscle O2 depletion must occur frequently: therefore, many dives require a significant energy contribution from anaerobic glycolysis.

  9. Effect of mibefradil on heart rate variability in patients with chronic heart failure

    NARCIS (Netherlands)

    Brouwer, J; de Kam, PJ; Haaksma, J; Crijns, HJGM; van Veldhuisen, DJ

    2000-01-01

    Background: Mibefradil was recently withdrawn from the market because of an unfavorable clinical profile in patients with chronic heart failure. Although drug interactions appear to play a role, other mechanisms such as proarrhythmia and autonomic deterioration could also be relevant. Chronic heart

  10. Association between the Rating Perceived Exertion, Heart Rate and Blood Lactate in Successive Judo Fights (Randori)

    Science.gov (United States)

    Branco, Braulio H.M.; Massuça, Luis M.; Andreato, Leonardo V.; Marinho, Bruno F.; Miarka, Bianca; Monteiro, Luis; Franchini, Emerson

    2013-01-01

    Purpose This study aims to investigate the association between the rating of perceived exertion (RPE), heart rate (HR) and the blood lactate concentration ([La]) in successive judo fight simulations (randori). Methods Ten athletes participated in the study (age: 25.6±2.1 years; stature: 1.75±0.07 m; body mass: 75.6±14.9kg; %BF: 11.5±7.8%; practice: 14.5±6.2 years) and completed 4 judo fight simulations (T1 to T4) with duration of 5 min separated by 5 min passive recovery periods. Before each randori, [La] and HR were collected, and after each randori, the same measures and the RPE (CR-10 scale) were collected. Results Significant correlations were observed between: (1) CR-10 and HR (T2: r =0.70; T3: r =0.64; both, Pjudo fight simulations (Pjudo, should be done with caution. PMID:23802054

  11. Absence of arterial baroreflex modulation of skin sympathetic activity and sweat rate during whole-body heating in humans

    Science.gov (United States)

    Wilson, T. E.; Cui, J.; Crandall, C. G.

    2001-01-01

    1. Prior findings suggest that baroreflexes are capable of modulating skin blood flow, but the effects of baroreceptor loading/unloading on sweating are less clear. Therefore, this project tested the hypothesis that pharmacologically induced alterations in arterial blood pressure in heated humans would lead to baroreflex-mediated changes in both skin sympathetic nerve activity (SSNA) and sweat rate. 2. In seven subjects mean arterial blood pressure was lowered (approximately 8 mmHg) and then raised (approximately 13 mmHg) by bolus injections of sodium nitroprusside and phenylephrine, respectively. Moreover, in a separate protocol, arterial blood pressure was reduced via steady-state administration of sodium nitroprusside. In both normothermia and heat-stress conditions the following responses were monitored: sublingual and mean skin temperatures, heart rate, beat-by-beat blood pressure, skin blood flow (laser-Doppler flowmetry), local sweat rate and SSNA (microneurography from peroneal nerve). 3. Whole-body heating increased skin and sublingual temperatures, heart rate, cutaneous blood flow, sweat rate and SSNA, but did not change arterial blood pressure. Heart rate was significantly elevated (from 74 +/- 3 to 92 +/- 4 beats x min(-1); P baroreflex function in these subjects. 4. Neither SSNA nor sweat rate was altered by rapid (bolus infusion) or sustained (steady-state infusion) changes in blood pressure regardless of the thermal condition. 5. These data suggest that SSNA and sweat rate are not modulated by arterial baroreflexes in normothermic or moderately heated individuals.

  12. Heart Rate Variability and the Efficacy of Biofeedback in Heroin Users with Depressive Symptoms.

    Science.gov (United States)

    Lin, I-Mei; Ko, Jiun-Min; Fan, Sheng-Yu; Yen, Cheng-Fang

    2016-05-31

    Low heart rate variability (HRV) has been confirmed in heroin users, but the effects of heart-rate-variability-biofeedback in heroin users remain unknown. This study examined (1) correlations between depression and HRV indices; (2) group differences in HRV indices among a heroin-user group, a group with major depressive disorder but no heroin use, and healthy controls; and (3) the effects of heart-rate-variability-biofeedback on depressive symptoms, HRV indices, and respiratory rates within the heroin group. All participants completed a depression questionnaire and underwent electrocardiogram measurements, and group differences in baseline HRV indices were examined. The heroin group underwent electrocardiogram and respiration rate measurements at baseline, during a depressive condition, and during a happiness condition, before and after which they took part in the heart-rate-variability-biofeedback program. The effects of heart-rate-variability-biofeedback on depressive symptoms, HRV indices, and respiration rates were examined. There was a negative correlation between depression and high frequency of HRV, and a positive correlation between depression and low frequency to high frequency ratio of HRV. The heroin group had a lower overall and high frequency of HRV, and a higher low frequency/high frequency ratio than healthy controls. The heart-rate-variability-biofeedback intervention increased HRV indices and decreased respiratory rates from pre-intervention to post-intervention. Reduced parasympathetic and increased sympathetic activations were found in heroin users. Heart-rate-variability- biofeedback was an effective non-pharmacological intervention to restore autonomic balance.

  13. Heart rate variability in conscious neonatal swine: spectral features and responses to short-term intermittent hypoxia

    Directory of Open Access Journals (Sweden)

    Zhao Ning

    2006-06-01

    Full Text Available Abstract Background Spectral analysis of the cardiac time series has been used as a tool for assessing levels of parasympathetic and sympathetic modulation of the sinoatrial node. In the present investigation we evaluated daily changes in heart rate variability spectra in conscious neonatal piglets that were either neurally intact (n = 5 or had undergone right stellate ganglionectomy (n = 5. The partial stellectomized animals and their intact litter mates were exposed to four days of intermittent hypoxia, each day comprising nine episodes of hypoxia alternating with nine episodes of normoxia. A time control group (n = 7 comprised animals from different litters that were not exposed to intermittent hypoxia. We hypothesized that exposure to intermittent hypoxia would increase sympathetic efferent neuronal modulation of heart rate variability spectra in neurally intact animals and in those with right stellate ganglionectomy, and that his effect would be observed in heart rate variability spectra computed from baseline recordings. Results Overall, heart rate variability spectra during baseline conditions were dominated by high frequency activity, a reflection of parasympathetic efferent neuronal innervation and linkage to the ventilatory cycle manifested as respiratory sinus arrhythmia. Exposure to intermittent hypoxia did not alter daily baseline spectral features that would indicate an increase of sympathetic cardiac activity: low frequency (0.05 – 0.15 Hz activity was unaffected and the ratio of low- to -high frequency activity remained less than unity indicating a predominance of high frequency activity. The resultant spectra were remarkably similar despite differences in cardiac sympathetic efferent neuronal innervation and experimental treatment. When spectra were computed from cardiac time series during representative hypoxic episodes, significant increases in activity across the low frequency region (0.05 – 0.15 Hz of heart rate

  14. Decreased nighttime heart rate variability is associated with increased stroke risk

    DEFF Research Database (Denmark)

    Binici, Zeynep; Mouridsen, Mette Rauhe; Køber, Lars

    2011-01-01

    Prediction of stroke in healthy individuals is challenging and there is a diurnal variation of stroke onset. We hypothesized that heart rate variability with a focus on nighttime heart rate variability will predict the risk of stroke in apparently healthy middle-age and elderly subjects....

  15. Variation in heart rate during submaximal exercise: Implications for monitoring training : Implications for monitoring training

    NARCIS (Netherlands)

    Lamberts, R.P.; Lemmink, K.A.P.M.; Durandt, J.J.; Lambert, M.I.

    2004-01-01

    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

  16. Identification of heart rate-associated loci and their effects on cardiac conduction and rhythm disorders

    NARCIS (Netherlands)

    den Hoed, Marcel; Eijgelsheim, Mark; Esko, Tonu; Brundel, Bianca J. J. M.; Peal, David S.; Evans, David M.; Nolte, Ilja M.; Segre, 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, Zoltan; Luan, Jian'an; Kemp, John P.; Kristiansson, Kati; Ladenvall, Claes; Lorentzon, Mattias; Montasser, May E.; Njajou, Omer T.; O'Reilly, Paul F.; Padmanabhan, Sandosh; Pourcain, Beate St.; 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, Soren; Chanock, Stephen J.; Chines, Peter S.; Chung, Mina; Darbar, Dawood; Dina, Christian; Doerr, 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; Kaeaeb, Stefan; Kanon, Bart; Ketkar, Shamika; Khaw, Kay-Tee; Knowles, Joshua W.; Kooner, Angrad S.; Kors, Jan A.; Kumari, Meena; Milani, Lili; Laiho, Paeivi; 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.; Mueller-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, Andre 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; Kahonen, Mika; Kiemeney, Lambertus A.; van der Klauw, Melanie M.; Kooner, Jaspal S.; Kraft, Peter; Iacoviello, Licia; Lehtimaki, 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, Gerard; 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

  17. Identifying genetic variants for heart rate variability in the acetylcholine pathway

    NARCIS (Netherlands)

    Riese, Harriëtte; Muñoz Venegas, Loretto; Hartman, Catharina A; Ding, Xiuhua; Su, Shaoyong; Oldehinkel, Albertine J; van Roon, Arie M; van der Most, Peter J; Lefrandt, Joop; Gansevoort, Ronald; van der Harst, Pim; Verweij, Niek; Licht, Carmilla M M; Boomsma, Dorret I; Hottenga, Jouke-Jan; Willemsen, Gonneke; Penninx, Brenda W J H; Nolte, Ilja M; de Geus, Eco J C; Wang, Xiaoling; Snieder, Harold

    2014-01-01

    Heart rate variability is an important risk factor for cardiovascular disease and all-causemortality. 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,

  18. Resemblances of Parents and Twins in Sport Participation and Heart Rate

    NARCIS (Netherlands)

    Boomsma, D.I.; van den Bree, M.B.; Orlebeke, J.F.; Molenaar, P.C.M.

    1989-01-01

    A model to analyze resemblances of twins and parents using LISREL is outlined and applied to sports participation and heart-rate data. Sports participation and heart rate were measured in 44 monozygotic and 46 dizygotic adolescent twin pairs and in their parents. Genetic factors influence variation

  19. Heart rate variability and the metabolic syndrome: a systematic review of the literature.

    Science.gov (United States)

    Stuckey, Melanie I; Tulppo, Mikko P; Kiviniemi, Antti M; Petrella, Robert J

    2014-11-01

    A number of cross-sectional studies have examined associations between heart rate variability and metabolic syndrome, but differences in study populations, data collection and analysis methodologies make synthesis difficult. The purpose of this study was to systematically review published primary research examining associations between heart rate variability and metabolic syndrome or its individual risk factors. A systematic literature search of PubMed and EMBASE was conducted to identify relevant articles published from January 1999 to December 2012. Studies were included if they examined associations between heart rate variability analysed by standard protocols and metabolic syndrome risk factors according to published definitions. All papers were scored with a modified Downs and Black instrument, and data were extracted. Fourteen studies were included. Heart rate variability generally was reduced in women with metabolic syndrome compared to those without, while results in men were inconsistent. Time and frequency domain heart rate variability parameters were associated with individual metabolic syndrome risk factors, though sex differences exist. Only two studies considered nonlinear and Poincaré plot heart rate variability parameters, which were reduced in metabolic syndrome. Heart rate variability is altered differently in men and women with metabolic syndrome. Future studies should follow consistent heart rate variability analysis protocols and metabolic syndrome definitions and include more comprehensive analyses to investigate potential mechanisms. Copyright © 2014 John Wiley & Sons, Ltd.

  20. [Heart rate variability is significantly reduced in non-diabetic patients with hypertension].

    Science.gov (United States)

    Nagy, Krisztina; Sipos, Evelin; El Hadj Othmane, Taha

    2014-06-01

    Heart rate variability is reduced among patients with hypertension and/or with diabetes mellitus. Hypertension and diabetes show frequent co-morbidity, but it is still not entirely clear whether heart rate variability is reduced in non-diabetic patients with hypertension. The aim of the authors was to evaluate the heart rate variability in hypertensive patients with and without diabetes and in control subjects. 130 patients with hypertension, 48 patients with hypertension and type 2 diabetes mellitus, and 87 control subjects were involved in the study. Minimum, mean and maximum heart rate, and parameters of heart rate variability were measured. The mean of minimum heart rate did not differ significantly between the three groups. However, all other parameters were significantly reduced in patients with hypertension with and without diabetes as compared to the control group. No significant differences were observed between hypertensive patients with and without diabetes mellitus. Heart rate variability is significantly reduced in non-diabetic patients with hypertension. It seems that type 2 diabetes results in no further significant reduction of heart rate variability in patients with hypertension.

  1. Elevated resting heart rate, physical fitness and all-cause mortality

    DEFF Research Database (Denmark)

    Jensen, Magnus Thorsten; Suadicani, Poul; Hein, Hans Ole

    2013-01-01

    To examine whether elevated resting heart rate (RHR) is an independent risk factor for mortality or a mere marker of physical fitness (VO2Max).......To examine whether elevated resting heart rate (RHR) is an independent risk factor for mortality or a mere marker of physical fitness (VO2Max)....

  2. Heart Rates of Elementary Physical Education Students during the Dancing Classrooms Program

    Science.gov (United States)

    Nelson, Larry; Evans, Melissa; Guess, Wendy; Morris, Mary; Olson, Terry; Buckwalter, John

    2011-01-01

    We examined how different types of dance activities, along with their duration, influenced heart rate responses among fifth-grade physical education students (N = 96) who participated in the Dancing Classrooms program. Results indicated that the overall Dancing Classrooms program elicits a moderate cardiovascular heart rate response (M = 124.4…

  3. Neighborhood blight, stress, and health: a walking trial of urban greening and ambulatory heart rate

    Science.gov (United States)

    Eugenia C. South; Michelle C. Kondo; Rose A. Cheney; Charles C. Branas

    2015-01-01

    We measured dynamic stress responses using ambulatory heart rate monitoring as participants in Philadelphia, Pennsylvania walked past vacant lots before and after a greening remediation treatment of randomly selected lots. Being in view of a greened vacant lot decreased heart rate significantly more than did being in view of a nongreened vacant lot or not in view of...

  4. Rate control management of atrial fibrillation: may a mathematical model suggest an ideal heart rate?

    Directory of Open Access Journals (Sweden)

    Matteo Anselmino

    Full Text Available 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.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.Left ventricular pressure increased by 57%, from 33.92±37.56 mmHg to 53.15±47.56 mmHg, and mean systemic arterial pressure increased by 27%, from 82.66±14.04 mmHg to 105.3±7.6 mmHg, at the 50 and 130 bpm simulations, respectively. Stroke volume (from 77.45±8.50 to 39.09±8.08 mL, ejection fraction (from 61.10±4.40 to 39.32±5.42% and stroke work (SW, from 0.88±0.04 to 0.58±0.09 J decreased by 50, 36 and 34%, at the 50 and 130 bpm simulations, respectively. In addition, oxygen consumption indexes (rate pressure product - RPP, tension time index per minute - TTI/min, and pressure volume area per minute - PVA/min increased from the 50 to the 130 bpm simulation, respectively, by 186% (from 5598±1939 to 15995±3219 mmHg/min, 56% (from 2094±265 to 3257±301 mmHg s/min and 102% (from 57.99±17.90 to 117.4±26.0 J/min. In fact, left ventricular efficiency (SW/PVA decreased from 80.91±2.91% at 50 bpm to 66.43±3.72% at the 130 bpm HR simulation.Awaiting compulsory direct clinical evidences, the present mathematical model suggests that lower HRs during permanent AF relates to improved hemodynamic parameters, cardiac efficiency, and lower oxygen consumption.

  5. Rate control management of atrial fibrillation: may a mathematical model suggest an ideal heart rate?

    Science.gov (United States)

    Anselmino, Matteo; Scarsoglio, Stefania; Camporeale, Carlo; Saglietto, Andrea; Gaita, Fiorenzo; Ridolfi, Luca

    2015-01-01

    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. 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. Left ventricular pressure increased by 57%, from 33.92±37.56 mmHg to 53.15±47.56 mmHg, and mean systemic arterial pressure increased by 27%, from 82.66±14.04 mmHg to 105.3±7.6 mmHg, at the 50 and 130 bpm simulations, respectively. Stroke volume (from 77.45±8.50 to 39.09±8.08 mL), ejection fraction (from 61.10±4.40 to 39.32±5.42%) and stroke work (SW, from 0.88±0.04 to 0.58±0.09 J) decreased by 50, 36 and 34%, at the 50 and 130 bpm simulations, respectively. In addition, oxygen consumption indexes (rate pressure product - RPP, tension time index per minute - TTI/min, and pressure volume area per minute - PVA/min) increased from the 50 to the 130 bpm simulation, respectively, by 186% (from 5598±1939 to 15995±3219 mmHg/min), 56% (from 2094±265 to 3257±301 mmHg s/min) and 102% (from 57.99±17.90 to 117.4±26.0 J/min). In fact, left ventricular efficiency (SW/PVA) decreased from 80.91±2.91% at 50 bpm to 66.43±3.72% at the 130 bpm HR simulation. Awaiting compulsory direct clinical evidences, the present mathematical model suggests that lower HRs during permanent AF relates to improved hemodynamic parameters, cardiac efficiency, and lower oxygen consumption.

  6. Effects of active and passive tobacco cigarette smoking on heart rate variability.

    Science.gov (United States)

    Dinas, Petros C; Koutedakis, Yiannis; Flouris, Andreas D

    2013-02-20

    Given the widespread incidence of smoking as well as its deleterious health effects, it is crucial to examine practical and cost effective prognostic markers assessing its health impact. Heart rate variability (HRV) is a straightforward and cost effective technique to foresee health problems of cardiovascular nature and may be used to predict in advance smoking-induced health effects. In this review we evaluate the existing biological evidence regarding the effects of smoking on HRV and their associated cardiovascular consequences. In addition, we summarize fundamental information on the various HRV indicators and their diagnostic significance in relation to heart failure. An in depth analysis of the various HRV indices characterizing changes in the activation of the autonomic nervous system is provided together with a critical evaluation of all evidence published to date on the influence of chronic and acute active and passive smoking on HRV. Overall, the vast majority of published evidence suggests that acute and chronic active and passive smoking generate marked disruptions in the normal autonomic nervous system functioning characterized by increased sympathetic drive and reduced HRV and parasympathetic modulation. The proposed mechanisms that may generate this smoke-induced HRV reduction as well as its clinical implications are thoroughly evaluated. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. Non-linear indices of heart rate variability during endodontic treatment.

    Science.gov (United States)

    Santana, Milana Drumond Ramos; Pita Neto, Ivo Cavalcante; Martiniano, Eli Carlos; Monteiro, Larissa Raylane Lucas; Ramos, José Lucas Souza; Garner, David M; Valenti, Vitor Engácia; Abreu, Luiz Carlos de

    2016-01-01

    Dental treatment promotes psychosomatic change that can influence the procedure and compromise the general well-being of the patient. In this context, it highlights the importance of evaluating the function of the autonomic nervous system in individuals undergoing endodontic treatment. Thus, this manuscript aimed to analyse cardiac autonomic modulation, through non-linear indices of heart rate variability (HRV) during endodontic treatment. Analysis of 50 subjects of either sex aged between 18 and 40 years diagnosed with irreversible pulp necrosis of lower molars undergoing endodontic treatment was undertaken. We carried out fractal and symbolic analysis of HRV, which was recorded in the first session of the endodontic treatment at four intervals: T1: 0-10 min before the onset of the treatment session; T2: 0-10 min after the application of anaesthesia; T3: throughout the period of treatment; and T4: 0-30 min after the end of the treatment session. There was reduction of α1 in T2 compared to T1 and T4 (p endodontic treatment, and after applying local anaesthetic the parasympathetic component of HRV increases. These data indicate that endodontic treatment acutely overcharges the heart, supporting the stress involved in this situation.

  8. Relationships between heart rate and age, bodyweight and breed in 10,849 dogs.

    Science.gov (United States)

    Hezzell, M J; Dennis, S G; Humm, K; Agee, L; Boswood, A

    2013-06-01

    To evaluate relationships between heart rate and clinical variables in healthy dogs and dogs examined at a referral hospital. Clinical data were extracted from the electronic patient records of a first opinion group (5000 healthy dogs) and a referral hospital (5849 dogs). Univariable and multi-variable general linear models were used to assess associations between heart rate and clinical characteristics. Separate multi-variable models were constructed for first opinion and referral populations. In healthy dogs, heart rate was negatively associated with bodyweight (Pborder collie, golden retriever, Labrador retriever, springer spaniel and West Highland white terrier and positively associated with age, admitting service (emergency and critical care, emergency first opinion and cardiology) and the following breeds; Cavalier King Charles spaniel, Staffordshire bull terrier and Yorkshire terrier. Bodyweight, age, breed and disease status all influence heart rate in dogs, although these factors account for a relatively small proportion of the overall variability in heart rate. © 2013 British Small Animal Veterinary Association.

  9. Aggressive behavior: an alternative model of resting heart rate and sensation seeking.

    Science.gov (United States)

    Wilson, Laura C; Scarpa, Angela

    2014-01-01

    Low resting heart rate is a well-replicated biological correlate of aggression, and sensation seeking is frequently cited as the underlying causal explanation. However, little empirical evidence supports this mediating relationship. Furthermore, the biosocial model of violence and social push theory suggest sensation seeking may moderate the relationship between heart rate and aggression. In a sample of 128 college students (82.0% White; 73.4% female), the current study tested a moderation model as an alternative relationship between resting heart rate and sensation seeking in regard to aggression. Overall, the findings partially supported an interaction effect, whereby the relationship between heart rate and aggression was moderated by sensation seeking. Specifically, the oft-noted relationship between low resting heart rate and increased aggression was found, but only for individuals with low levels of sensation seeking. If replication supports this finding, the results may better inform prevention and intervention work. © 2013 Wiley Periodicals, Inc.

  10. Heart rate variability in leucine-rich repeat kinase 2-associated Parkinson's disease.

    Science.gov (United States)

    Visanji, Naomi P; Bhudhikanok, Grace S; Mestre, Tiago A; Ghate, Taneera; Udupa, Kaviraj; AlDakheel, Amaal; Connolly, Barbara S; Gasca-Salas, Carmen; Kern, Drew S; Jain, Jennifer; Slow, Elizabeth J; Faust-Socher, Achinoam; Kim, Sam; Azhu Valappil, Ruksana; Kausar, Farah; Rogaeva, Ekaterina; William Langston, J; Tanner, Caroline M; Schüle, Birgitt; Lang, Anthony E; Goldman, Samuel M; Marras, Connie

    2017-04-01

    Heart rate variability is reduced in idiopathic PD, indicating cardiac autonomic dysfunction likely resulting from peripheral autonomic synucleinopathy. Little is known about heart rate variability in leucine-rich repeat kinase 2-associated PD. This study investigated heart rate variability in LRRK2-associated PD. Resting electrocardiograms were obtained from 20 individuals with LRRK2-associated PD, 37 nonmanifesting carriers, 48 related noncarriers, 26 idiopathic PD patients, and 32 controls. Linear regression modelling compared time and frequency domain values, adjusting for age, sex, heart rate, and disease duration. Low-frequency power and the ratio of low-high frequency power were reduced in idiopathic PD versus controls (P Heart rate variability may remain intact in LRRK2-associated PD, adding to a growing literature supporting clinical-pathologic differences between LRRK2-associated and idiopathic PD. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

  11. Impact of QRS morphology on heart rate turbulence and heart rate variability after cardiac resynchronization therapy in patients with heart failure.

    Science.gov (United States)

    Soylu, M O; Altun, I; Basaran, O; Uzun, Y; Dogan, V; Ergun, G; Akin, F; Biteker, M

    2016-01-01

    Impairment of heart rate turbulence (HRT) and heart rate variability (HRV) are associated with poor prognosis in chronic heart failure (CHF). Although previous studies have demonstrated that patients with a left bundle branch block (LBBB) have a better outcome with cardiac resynchronization therapy (CRT), the effect of QRS morphology on HRV and HRT is not known. We aimed to evaluate the effect of QRS morphology on HRV and HRT after CRT implantation in patients with CHF. Patients who had been implanted a CRT device with cardioversion-defibrillation feature were included to the study. Forty-three patients with LBBB (group 1) were compared with 21 patients without LBBB (group 2). HRV and HRT parameters were compared before and one month after CRT implantation. We compared the echocardiographic and electrocardiographic changes in both groups after CRT. Cardiac output (CO) was found to be significantly much more increased in group 1 (1.1 ± 0.4 vs. 0.6 ± 0.4, p = 0.001). Similarly, except SDNN and LF, all HRT and HRV parameters were significantly changed in the patients with LBBB (TO 1.4 ± 0.3 vs. 1.2 ± 0.2, p = 0.001; TS -1.8 ± 0.7 vs. -0.9 ± 0.7, p = 0.001; RMSSD -15.7 ± 9.9 vs. -6.3 ± 6.2, p = 0.001; PNN50 -7.0 ± 4.6 vs. -1.7 ± 1.1, p = 0.001; HF -13.3 ± 6.7 vs. -4.3 ± 3.5, p = 0.001; LF/HF 1.9 ± 0.4 vs. 1.5 ± 0.2, p = 0.001) compared to those without LBBB. Lineer regression analysis showed that the CO (β = 0.2, t = 2.8, p = 0.007) and QRS configuration (β = 0.6, t = 0.5, p = 0.001) were independent parameters affecting TO. HRV and HRT are improved after CRT but these improvements are more remarkable in patients with LBBB. CO, QRS configuration (but not duration) were two independent parameters affecting TO, LF and LF/HF ratio after CRT.

  12. Generating pulsatility by pump speed modulation with continuous-flow total artificial heart in awake calves.

    Science.gov (United States)

    Fukamachi, Kiyotaka; Karimov, Jamshid H; Sunagawa, Gengo; Horvath, David J; Byram, Nicole; Kuban, Barry D; Dessoffy, Raymond; Sale, Shiva; Golding, Leonard A R; Moazami, Nader

    2017-12-01

    The purpose of this study was to evaluate the effects of sinusoidal pump speed modulation of the Cleveland Clinic continuous-flow total artificial heart (CFTAH) on hemodynamics and pump flow in an awake chronic calf model. The sinusoidal pump speed modulations, performed on the day of elective sacrifice, were set at ±15 and ± 25% of mean pump speed at 80 bpm in four awake calves with a CFTAH. The systemic and pulmonary arterial pulse pressures increased to 12.0 and 12.3 mmHg (±15% modulation) and to 15.9 and 15.7 mmHg (±25% modulation), respectively. The pulsatility index and surplus hemodynamic energy significantly increased, respectively, to 1.05 and 1346 ergs/cm at ±15% speed modulation and to 1.51 and 3381 ergs/cm at ±25% speed modulation. This study showed that it is feasible to generate pressure pulsatility with pump speed modulation; the platform is suitable for evaluating the physiologic impact of pulsatility and allows determination of the best speed modulations in terms of magnitude, frequency, and profiles.

  13. Introduction to Controversial Topics in Nonlinear Science: Is the Normal Heart Rate Chaotic?

    Science.gov (United States)

    Glass, Leon

    2009-06-01

    In June 2008, the editors of Chaos decided to institute a new section to appear from time to time that addresses timely and controversial topics related to nonlinear science. The first of these deals with the dynamical characterization of human heart rate variability. We asked authors to respond to the following questions: Is the normal heart rate chaotic? If the normal heart rate is not chaotic, is there some more appropriate term to characterize the fluctuations (e.g., scaling, fractal, multifractal)? How does the analysis of heart rate variability elucidate the underlying mechanisms controlling the heart rate? Do any analyses of heart rate variability provide clinical information that can be useful in medical assessment (e.g., in helping to assess the risk of sudden cardiac death)? If so, please indicate what additional clinical studies would be useful for measures of heart rate variability to be more broadly accepted by the medical community. In addition, as a challenge for analysis methods, PhysioNet [A. L. Goldberger et al., "PhysioBank, PhysioToolkit, and PhysioNet: Components of a new research resource for complex physiologic signals," Circulation 101, e215-e220 (2000)] provided data sets from 15 patients of whom five were normal, five had heart failure, and five had atrial fibrillation (http://www.physionet.org/challenge/chaos/). This introductory essay summarizes the main issues and introduces the essays that respond to these questions.

  14. Impact of Narrative Expressive Writing on Heart Rate, Heart Rate Variability, and Blood Pressure After Marital Separation.

    Science.gov (United States)

    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.

  15. Rate adaptive multilevel coded modulation with high coding gain in intensity modulation direct detection optical communication

    Science.gov (United States)

    Xiao, Fei; Liu, Bo; Zhang, Lijia; Xin, Xiangjun; Zhang, Qi; Tian, Qinghua; Tian, Feng; Wang, Yongjun; Rao, Lan; Ullah, Rahat; Zhao, Feng; Li, Deng'ao

    2018-02-01

    A rate-adaptive multilevel coded modulation (RA-MLC) scheme based on fixed code length and a corresponding decoding scheme is proposed. RA-MLC scheme combines the multilevel coded and modulation technology with the binary linear block code at the transmitter. Bits division, coding, optional interleaving, and modulation are carried out by the preset rule, then transmitted through standard single mode fiber span equal to 100 km. The receiver improves the accuracy of decoding by means of soft information passing through different layers, which enhances the performance. Simulations are carried out in an intensity modulation-direct detection optical communication system using MATLAB®. Results show that the RA-MLC scheme can achieve bit error rate of 1E-5 when optical signal-to-noise ratio is 20.7 dB. It also reduced the number of decoders by 72% and realized 22 rate adaptation without significantly increasing the computing time. The coding gain is increased by 7.3 dB at BER=1E-3.

  16. Gender- and age-related differences in heart rate dynamics: are women more complex than men?

    Science.gov (United States)

    Ryan, S. M.; Goldberger, A. L.; Pincus, S. M.; Mietus, J.; Lipsitz, L. A.

    1994-01-01

    OBJECTIVES. This study aimed to quantify the complex dynamics of beat-to-beat sinus rhythm heart rate fluctuations and to determine their differences as a function of gender and age. BACKGROUND. Recently, measures of heart rate variability and the nonlinear "complexity" of heart rate dynamics have been used as indicators of cardiovascular health. Because women have lower cardiovascular risk and greater longevity than men, we postulated that there are important gender-related differences in beat-to-beat heart rate dynamics. METHODS. We analyzed heart rate dynamics during 8-min segments of continuous electrocardiographic recording in healthy young (20 to 39 years old), middle-aged (40 to 64 years old) and elderly (65 to 90 years old) men (n = 40) and women (n = 27) while they performed spontaneous and metronomic (15 breaths/min) breathing. Relatively high (0.15 to 0.40 Hz) and low (0.01 to 0.15 Hz) frequency components of heart rate variability were computed using spectral analysis. The overall "complexity" of each heart rate time series was quantified by its approximate entropy, a measure of regularity derived from nonlinear dynamics ("chaos" theory). RESULTS. Mean heart rate did not differ between the age groups or genders. High frequency heart rate power and the high/low frequency power ratio decreased with age in both men and women (p gender-as well as age-related differences in heart rate dynamics. Whether these gender differences are related to lower cardiovascular disease risk and greater longevity in women requires further study.

  17. Heart Disease Death Rates in Low Versus High Land Elevation Counties in the U.S

    OpenAIRE

    Hart, John

    2015-01-01

    Previous research on land elevation and cancer death rates in the U.S. revealed lower cancer death rates in higher elevations. The present study further tests the possible effect of land elevation on a diffident health outcome, namely, heart disease death rates. U.S. counties not overlapping in their land elevations according to their lowest and highest elevation points were identified. Using an ecological design, heart disease death rates for two races (black and white) corresponding to lowe...

  18. A healthy heart is not a metronome: An integrative review of the heart’s anatomy and heart rate variability

    Directory of Open Access Journals (Sweden)

    Fredric Bruce Shaffer

    2014-09-01

    Full Text Available 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, Vaschillo, and Vaschillo’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.

  19. DYNAMIC CHANGES IN SPECTRAL HEART RATE VARIABILITY PARAMETERS IN PACED BREATHING TEST IN PATIENT WITH UNCONTROLLED ARTERIAL HYPERTENSION AND POLYMORBIDITY

    Directory of Open Access Journals (Sweden)

    L. Oyeleye

    2016-12-01

    Full Text Available A clinical case of a patient with uncontrolled hypertension and polymorbidity. The paced breathing test was made, was found prevalence of low frequency influences at the initial stage and its intensification at the resting stage, growth of the total power of heart rate variability spectrum (TP with respiratory modulation. The course of the disease worsened the appearance of new-onset atrial fibrillation (registered paroxysm on Holter monitoring; the general deterioration of the patient’s state reflected HRV changes on sinus rhythm tracing - significantly reduced TP growth in response to paced breathing, an increase in LF/HF (ratio of low frequency to high frequency waves, as well as switching to the neurohormonal level of heart rate regulation at the resting stage. After the treatment the growth of TP in response to the test has increased and LF/HF level has decreased.

  20. Neuro-Cardiac-Guided TMS (NCG-TMS) : Probing DLPFC-sgACC-vagus nerve connectivity using heart rate - First results

    NARCIS (Netherlands)

    Iseger, Tabitha A.; Padberg, Frank; Kenemans, J Leon; Gevirtz, Richard; Arns, Martijn

    2017-01-01

    BACKGROUND: Given that many studies suggest a role of DLPFC-sgACC connectivity in depression and prior research demonstrating that neuromodulation of either of these nodes modulates parasympathetic activity and results in a heart rate deceleration, a new method is proposed to individualize

  1. The intubating laryngeal mask produces less heart rate response to ...

    African Journals Online (AJOL)

    Blind intubation through the ILM using a straight silicone tracheal tube manufactured for specific use with the ILM; 2. Intubation with a size 3 macintosh laryngoscope ... such as in patients with ischaemic heart disease. Key Words: Equipment:intubating laryngeal mask airway; Airway,complications: haemodynamic response ...

  2. Effects of maternal breathing rate, psychiatric status, and cortisol on fetal heart rate.

    Science.gov (United States)

    Monk, Catherine; Fifer, William P; Myers, Michael M; Bagiella, Emilia; Duong, Jimmy K; Chen, Ivy S; Leotti, Lauren; Altincatal, Arman

    2011-04-01

    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 psychobiology. Copyright © 2010 Wiley Periodicals, Inc.

  3. Validation of heart rate extraction through an iPhone accelerometer.

    Science.gov (United States)

    Kwon, Sungjun; Lee, Jeongsu; Chung, Gih Sung; Park, Kwang Suk

    2011-01-01

    Ubiquitous medical technology may provide advanced utility for evaluating the status of the patient beyond the clinical environment. The iPhone provides the capacity to measure the heart rate, as the iPhone consists of a 3-axis accelerometer that is sufficiently sensitive to perceive tiny body movements caused by heart pumping. In this preliminary study, an iPhone was tested and evaluated as the reliable heart rate extractor to use for medical purpose by comparing with reference electrocardiogram. By comparing the extracted heart rate from acquired acceleration data with the extracted one from ECG reference signal, iPhone functioning as the reliable heart rate extractor has demonstrated sufficient accuracy and consistency.

  4. Gender- and age-related differences in heart rate dynamics: are women more complex than men?

    Science.gov (United States)

    Ryan, S. M.; Goldberger, A. L.; Pincus, S. M.; Mietus, J.; Lipsitz, L. A.

    1994-01-01

    OBJECTIVES. This study aimed to quantify the complex dynamics of beat-to-beat sinus rhythm heart rate fluctuations and to determine their differences as a function of gender and age. BACKGROUND. Recently, measures of heart rate variability and the nonlinear "complexity" of heart rate dynamics have been used as indicators of cardiovascular health. Because women have lower cardiovascular risk and greater longevity than men, we postulated that there are important gender-related differences in beat-to-beat heart rate dynamics. METHODS. We analyzed heart rate dynamics during 8-min segments of continuous electrocardiographic recording in healthy young (20 to 39 years old), middle-aged (40 to 64 years old) and elderly (65 to 90 years old) men (n = 40) and women (n = 27) while they performed spontaneous and metronomic (15 breaths/min) breathing. Relatively high (0.15 to 0.40 Hz) and low (0.01 to 0.15 Hz) frequency components of heart rate variability were computed using spectral analysis. The overall "complexity" of each heart rate time series was quantified by its approximate entropy, a measure of regularity derived from nonlinear dynamics ("chaos" theory). RESULTS. Mean heart rate did not differ between the age groups or genders. High frequency heart rate power and the high/low frequency power ratio decreased with age in both men and women (p < 0.05). The high/low frequency power ratio during spontaneous and metronomic breathing was greater in women than men (p < 0.05). Heart rate approximate entropy decreased with age and was higher in women than men (p < 0.05). CONCLUSIONS. High frequency heart rate spectral power (associated with parasympathetic activity) and the overall complexity of heart rate dynamics are higher in women than men. These complementary findings indicate the need to account for gender-as well as age-related differences in heart rate dynamics. Whether these gender differences are related to lower cardiovascular disease risk and greater longevity in

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

    Science.gov (United States)

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

    2007-01-01

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

  6. The low frequency power of heart rate variability is neither a measure of cardiac sympathetic tone nor of baroreflex sensitivity.

    Science.gov (United States)

    Martelli, Davide; Silvani, Alessandro; McAllen, Robin M; May, Clive N; Ramchandra, Rohit

    2014-10-01

    The lack of noninvasive approaches to measure cardiac sympathetic nerve activity (CSNA) has driven the development of indirect estimates such as the low-frequency (LF) power of heart rate variability (HRV). Recently, it has been suggested that LF HRV can be used to estimate the baroreflex modulation of heart period (HP) rather than cardiac sympathetic tone. To test this hypothesis, we measured CSNA, HP, blood pressure (BP), and baroreflex sensitivity (BRS) of HP, estimated with the modified Oxford technique, in conscious sheep with pacing-induced heart failure and in healthy control sheep. We found that CSNA was higher and systolic BP and HP were lower in sheep with heart failure than in control sheep. Cross-correlation analysis showed that in each group, the beat-to-beat changes in HP correlated with those in CSNA and in BP, but LF HRV did not correlate significantly with either CSNA or BRS. However, when control sheep and sheep with heart failure were considered together, CSNA correlated negatively with HP and BRS. There was also a negative correlation between CSNA and BRS in control sheep when considered alone. In conclusion, we demonstrate that in conscious sheep, LF HRV is neither a robust index of CSNA nor of BRS and is outperformed by HP and BRS in tracking CSNA. These results do not support the use of LF HRV as a noninvasive estimate of either CSNA or baroreflex function, but they highlight a link between CSNA and BRS. Copyright © 2014 the American Physiological Society.

  7. Cycling before and after Exhaustion Differently Affects Cardiac Autonomic Control during Heart Rate Matched Exercise.

    Science.gov (United States)

    Weippert, Matthias; Behrens, Martin; Mau-Moeller, Anett; Bruhn, Sven; Behrens, Kristin

    2017-01-01

    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.

  8. Opportunity for information search and the effect of false heart rate feedback.

    Science.gov (United States)

    Barefoot, John C; Straub, Ronald B

    2005-01-01

    The role of information search in the attribution of physiological states was investigated by manipulating the subject's opportunity for information search following the presentation of false information about his heart-rate reactions to photographs of female nudes. Consistent with the self-persuasion hypothesis proposed by Valins, the rated attractiveness of the slides was not affected by the false heart-rate feedback for those subjects who were prevented from visually searching the slides. Those subjects who had ample opportunity to view the slides rated those slides accompanied by false information of a heart-rate change as more attractive than those slides which were not paired with a change in heart rate.

  9. Visibility graph analysis of heart rate time series and bio-marker of congestive heart failure

    Science.gov (United States)

    Bhaduri, Anirban; Bhaduri, Susmita; Ghosh, Dipak

    2017-09-01

    Study of RR interval time series for Congestive Heart Failure had been an area of study with different methods including non-linear methods. In this article the cardiac dynamics of heart beat are explored in the light of complex network analysis, viz. visibility graph method. Heart beat (RR Interval) time series data taken from Physionet database [46, 47] belonging to two groups of subjects, diseased (congestive heart failure) (29 in number) and normal (54 in number) are analyzed with the technique. The overall results show that a quantitative parameter can significantly differentiate between the diseased subjects and the normal subjects as well as different stages of the disease. Further, the data when split into periods of around 1 hour each and analyzed separately, also shows the same consistent differences. This quantitative parameter obtained using the visibility graph analysis thereby can be used as a potential bio-marker as well as a subsequent alarm generation mechanism for predicting the onset of Congestive Heart Failure.

  10. Design of heart rate monitor based on piezoelectric sensor using an Arduino

    Science.gov (United States)

    Setyowati, Veni; Muninggar, Jodelin; Shanti. N. A, Made R. S.

    2017-01-01

    Reading of result heart rate using an acoustic stethoscope needs a particular skill, quiet environment, and hearing sensitivity. This project had the purpose design of a user-friendly automatic heart rate monitor and especially in a noisy area which to eliminate problems and incorrect reading of result. The liquid crystal display shows a heart rate as a result of measurements. The design of the heart rate monitor has two main parts; the signal recorder that a piezoelectric sensor, a filter, and an amplifier as recorder. The second parts was Arduino microcontroller with reinforced. Besides, three supporting buttons provided as the manual switches, the ‘on’, the ‘start’, and ‘reset’ buttons. The values acquired from the heart rate monitor indicate that those were on the Vernier BPS-BTA value range. The measurement error factor of the heart rate monitor then compared to the Vernier BPS-BTA test device was 3.15%. Besides, the value of statistical independent-test indicates that there is no significant difference (P = 0.971) between the heart rate monitor device and the Vernier BPS-BTA. In conclusion, this device was ready to be used because it has almost the same accuracy with the standart device.

  11. Daily physical activity and heart rate response in people with a unilateral traumatic transtibial amputation.

    Science.gov (United States)

    Bussmann, Johannes B; Schrauwen, Hannelore J; Stam, Henk J

    2008-03-01

    To test the hypothesis that people with a unilateral traumatic transtibial amputation are less active than people without an amputation, and to explore whether both groups have a similar heart rate response while walking. A case-comparison study. General community. Nine subjects with a unilateral traumatic transtibial amputation and 9 matched subjects without known impairments. Not applicable. Percentage of dynamic activities in 48 hours (expressing activity level). Additionally, we examined heart rate and percentage heart rate reserve during walking (expressing heart rate response) and body motility during walking (expressing walking speed). These parameters were objectively measured at participants' homes on 2 consecutive days. Subjects with an amputation showed a lower percentage of dynamic activities (6.0% vs 11.7% in a 48-h period, P=.02). No significant differences were found between the 2 groups in heart rate (91.1 bpm vs 89.5 bpm, P=.86) and percentage heart rate reserve during walking (28.2% vs 27.5%, P=1.0). Body motility during walking was lower in the amputation group (.14 g vs .18 g, Ptraumatic transtibial amputation are considerably less active than persons without known impairments. The results indicate that heart rate response during walking is similar in both groups, and is probably regulated by adapting one's walking speed.

  12. Variation in heart rate influences the assessment of transient ischemic dilation in myocardial perfusion scintigraphy

    International Nuclear Information System (INIS)

    Leslie, William D; Levin, Daniel P; Demeter, Sandor J

    2007-01-01

    Transient arrhythmias can affect transient ischemic dilation (TID) ratios. This study was initiated to evaluate the frequency and effect of normal heart rate change on TID measures in routine clinical practice. Consecutive patients undergoing stress/rest sestamibi gated myocardial perfusion scintigraphy were studied (N = 407). Heart rate at the time of stress and rest imaging were recorded. TID ratios were analyzed in relation to absolute change in heart rate (stress minus rest) for subjects with normal perfusion and systolic function (Group 1, N = 169) and those with abnormalities in perfusion and/or function (Group 2, N = 238). In Group 1, mean TID ratio was inversely correlated with the change in heart rate (r = -0.47, P < 0.0001). For every increase of 10 BPM in heart rate change, the TID ratio decreased by approximately 0.06 (95% confidence interval 0.04–0.07). In Group 2, multiple linear regression demonstrated that the change in heart rate (beta = -0.25, P < 0.0001) and the summed difference score (beta = 0.36, P < 0.0001) were independent predictors of the TID ratio. Normal variation in heart rate between the stress and rest components of myocardial perfusion scans is common and can influence TID ratios in patients with normal and abnormal cardiac scans

  13. Changes in Heart Rate Variability in a Premature Infant with Hydrocephalus

    Directory of Open Access Journals (Sweden)

    Zuzana Uhrikova

    2012-11-01

    Full Text Available Objective - To define changes of heart rate variability in premature infant with hydrocephalus before and after drainage procedure. Study Design - The authors report a case of a premature infant with hydrocephalus with analysis of heart rate variability before and after drainage procedure. Three subsequent recordings of the electrocardiography and heart rate variability were done: the first at the age of 22 days before insertion of ventriculoperitoneal shunt, the second at the age of 36 days with functional shunt, the third at the age of 71 days (before discharge. Results - Before drainage operation, there was reduced heart rate variability in time and spectral domains, and sympathetic activity was dominant. After surgery, an increase in heart rate variability parameters was found, particularly with spectral analysis. The ratio of low-frequency/high-frequency band and relative power of the low-frequency band decreased, reflecting enhanced parasympathetic activity. Conclusion - Results of the heart rate variability analysis in a preterm infant with hydrocephalus before and after drainage procedure showed marked improvement in chronotropic cardiac regulation. Evaluation of heart rate variability in premature infants with hydrocephalus with increased intracranial pressure can be an additional method for monitoring of cardiac dysregulation and improvement of the cardiovascular control after successful drainage procedure.

  14. Change of Diurnal Heart Rate Patterns During Pregnancy and Lactation in Dogs (Canis familiaris

    Directory of Open Access Journals (Sweden)

    Häggström J

    2003-09-01

    Full Text Available Pregnancy and lactation involve great demands on the cardiovascular system. The purpose of this study was to investigate how the heart rate and diurnal heart rate pattern change when dogs become pregnant or lactate. Five clinically healthy female beagle dogs were mated, and delivered three to seven healthy puppies. The heart rate was investigated with 24-h ECG (Holter once during anoestrus, at 3, 5, 7 and 9 weeks of pregnancy, and at week 4 postpartum (lactation. However, at 9 weeks, the ECG could not be recorded for the fully 24 h in 4 of 5 dogs, because labour started and the dogs then appeared disturbed by the recordings. The results at this date are not included in the statistical comparison. The heart rate increased progressively during pregnancy and was still elevated at 4 weeks of lactation. During late pregnancy the difference in heart rates between daytime and nighttime became smaller, but the heart rate was significantly higher in daytime in all periods. In conclusion, the increased heart rates during pregnancy and lactation reflect increased demands on the cardiovascular system and may be important to consider in clinical practice.

  15. Minimal changes in heart rate of incubating American Oystercatchers (Haematopus palliatus) in response to human activity

    Science.gov (United States)

    Borneman, Tracy E.; Rose, Eli T.; Simons, Theodore R.

    2014-01-01

    An organism's heart rate is commonly used as an indicator of physiological stress due to environmental stimuli. We used heart rate to monitor the physiological response of American Oystercatchers (Haematopus palliatus) to human activity in their nesting environment. We placed artificial eggs with embedded microphones in 42 oystercatcher nests to record the heart rate of incubating oystercatchers continuously for up to 27 days. We used continuous video and audio recordings collected simultaneously at the nests to relate physiological response of birds (heart rate) to various types of human activity. We observed military and civilian aircraft, off-road vehicles, and pedestrians around nests. With the exception of high-speed, low-altitude military overflights, we found little evidence that oystercatcher heart rates were influenced by most types of human activity. The low-altitude flights were the only human activity to significantly increase average heart rates of incubating oystercatchers (12% above baseline). Although statistically significant, we do not consider the increase in heart rate during high-speed, low-altitude military overflights to be of biological significance. This noninvasive technique may be appropriate for other studies of stress in nesting birds.

  16. The relationship between heart rate as an indicator of work hardness and results of dynamometry.

    Science.gov (United States)

    Sadeghi, Nasrin; Tolide-ie, Hamidreza; Ghaderi, Fatemeh

    2012-01-01

    Heart rate is associated with work hardness and increase linearly with its increasing. In the average of energy consumption, heart rate measurement is simple but non-accurate method for calculation of work hardness. Our purpose in this research was to evaluate the relationship between heart rate and dynamometry results with hypothesis of work hardness effectiveness on the human power. This study was conducted on 102 porcelain workers. Participants were selected randomly. The research tools include stethoscope, the dynamometer. Heart rate, and pinch, grip, and back-leg-chest force were measured and relationships between variables were analyzed with Pearson correlation test and independent T-test using Spss 16 software. The average heart rate of participants were 4.11 ± 1.79 with minimum 60 and maximum 120. The average force of pinch, grip, and back-leg-chest were 8.9 ± 3.20, 4.2 ± 4.5 and 9.36 ± 6.55, respectively. Work hardness for 3.86% of workers were light, 7.12% were moderate and 1% were heavy. Pinch, grip, and back-leg-chest force relation with heart rate were not significant (r=0.01, p=0.85), (r=-0.03, p=0.74), and (r=0.05, p= 0.59), respectively. There was no correlation between heart rate and work hardness. So we can't use the dynamometry results to determine of work hardness.

  17. Altered heart rate and blood pressure variability in mice lacking the Mas protooncogene

    Directory of Open Access Journals (Sweden)

    T. Walther

    2000-01-01

    Full Text Available Heart rate variability is a relevant predictor of cardiovascular risk in humans. A significant genetic influence on heart rate variability is suggested, although the genes involved are ill-defined. The Mas-protooncogene encodes a G-protein-coupled receptor with seven transmembrane domains highly expressed in testis and brain. Since this receptor is supposed to interact with the signaling of angiotensin II, which is an important regulator of cardiovascular homeostasis, heart rate and blood pressure were analyzed in Mas-deficient mice. Using a femoral catheter the blood pressure of mice was measured for a period of 30 min and 250 data values per second were recorded. The mean values and range of heart rate and blood pressure were then calculated. Neither heart rate nor blood pressure were significantly different between knockout mice and controls. However, high resolution recording of these parameters and analysis of the data by non-linear dynamics revealed significant alterations in cardiovascular variability in Mas-deficient animals. In particular, females showed a strong reduction of heart rate variability. Furthermore, the data showed an increased sympathetic tone in knockout animals of both genders. The marked alterations detected in Mas-deficient mice of both genders suggest that the Mas-protooncogene is an important determinant of heart rate and blood pressure variability.

  18. Autonomic modulation of arterial pressure and heart rate variability in hypertensive diabetic rats Modulação autonômica da pressão arterial e variabilidade da freqüência cardíaca em ratos hipertensos e diabéticos

    Directory of Open Access Journals (Sweden)

    Vera de Moura Azevedo Farah

    2007-01-01

    Full Text Available OBJECTIVE: The aim of the present study was to evaluate the autonomic modulation of the cardiovascular system in streptozotocin (STZ-induced diabetic spontaneously hypertensive rats (SHR, evaluating baroreflex sensitivity and arterial pressure and heart rate variability. METHODS: Male SHR were divided in control (SHR and diabetic (SHR+DM, 5 days after STZ groups. Arterial pressure (AP and baroreflex sensitivity (evaluated by tachycardic and bradycardic responses to changes in AP were monitored. Autoregressive spectral estimation was performed for systolic AP (SAP and pulse interval (PI with oscillatory components quantified as low (LF:0.2-0.6Hz and high (HF:0.6-3.0Hz frequency ranges. RESULTS: Mean AP and heart rate in SHR+DM (131±3 mmHg and 276±6 bpm were lower than in SHR (160±7 mmHg and 330±8 bpm. Baroreflex bradycardia was lower in SHR+DM as compared to SHR (0.55±0.1 vs. 0.97±0.1 bpm/mmHg. Overall SAP variability in the time domain (standard deviation of beat-by-beat time series of SAP was lower in SHR+DM (3.1±0.2 mmHg than in SHR (5.7±0.6 mmHg. The standard deviation of the PI was similar between groups. Diabetes reduced the LF of SAP (3.3±0.8 vs. 28.7±7.6 mmHg2 in SHR, while HF of SAP were unchanged. The power of oscillatory components of PI did not differ between groups. CONCLUSIONS: These results show that the association of hypertension and diabetes causes an impairment of the peripheral cardiovascular sympathetic modulation that could be, at least in part, responsible for the reduction in AP levels. Moreover, this study demonstrates that diabetes might actually impair the reduced buffer function of the baroreceptors while reducing blood pressure.OBJETIVO: O objetivo do presente estudo foi investigar a modulação autonômica do sistema cardiovascular em ratos espontâneamente hipertensos (SHR e diabéticos por estreptozotocina (STZ, avaliando a sensibilidade do reflexo barorreceptor e a variabilidade da pressão arterial e da

  19. Determinants of heart rate turbulence in individuals without apparent heart disease and in patients with stable coronary artery disease.

    Science.gov (United States)

    Pinnacchio, Gaetano; Lanza, Gaetano Antonio; Stazi, Alessandra; Careri, Giulia; Coviello, Ilaria; Mollo, Roberto; Crea, Filippo

    2015-12-01

    To assess the characteristics and determinants of heart rate turbulence (HRT) in individuals without any apparent heart disease and in patients with coronary artery disease (CAD). Heart rate turbulence parameters, turbulence onset (TO), and turbulence slope (TS) were calculated on 24 h electrocardiogram recordings in 209 individuals without any heart disease (group 1) and in 157 CAD patients (group 2). In group 1, only age independently predicted abnormal TO (≥0%) [odds ratio (OR), 1.05; PCoronary artery disease group, however, did not predict abnormal HRT parameters in multivariable analyses, both in the whole population and when comparing two subgroups matched for age and gender. Age and (for TS) LVEF, indeed, were the only independent predictors of abnormal HRT. Age is a major HRT determinant both in subjects without any apparent heart disease and in stable CAD patients. Hypertension and LVEF contribute independently to HRT in these two groups, respectively. Coronary artery disease group was not by itself associated with abnormal HRT parameters in multivariable analyses. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  20. Differences in heart rate profile during exercise among subjects with subclinical thyroid disease.

    Science.gov (United States)

    Maor, Elad; Kivity, Shaye; Kopel, Eran; Segev, Shlomo; Sidi, Yechezkel; Goldenberg, Ilan; Olchovsky, David

    2013-10-01

    Clinical thyroid disease is associated with changes in the cardiovascular system, including changes in heart rate during exercise. However, data on the relation between subclinical thyroid disease (SCTD) and heart rate during exercise are limited. We investigated 3799 apparently healthy subjects who were evaluated in the Institute for Preventive Medicine at the Sheba Medical Center. All subjects answered standard health questionnaires; were examined by a physician; completed routine blood tests including thyrotropin, free triiodothyronine, and free thyroxine levels; and underwent a treadmill exercise according to the Bruce protocol. Subjects with known thyroid disease or those who were taking thyroid-related drugs were excluded from the analysis. Heart rate profile was compared between patients with subclinical hypothyroidism (SCHypoT), patients with normal thyroid function, and patients with subclinical hyperthyroidism (SCHyperT) using propensity score matching. Seventy patients had SCHyperT and 273 had SCHypoT. Compared with age- and sex-matched normal subjects, SCHyperT subjects had a higher resting heart rate (83±17 vs. 76±12 beats per minute [bpm], p=0.006), a significantly higher recovery heart rate (94±12 vs. 90±12 bpm, p=0.045), and a significantly lower heart rate reserve (80±20 vs. 87±18 bpm, p=0.006). Subjects with SCHypoT showed a trend toward a lower resting heart rate (75±13 vs. 77±15 bpm, p=0.09) and had a significantly lower recovery heart rate (88±12 vs. 90±13 bpm, p=0.035). There was no significant difference in exercise duration or blood pressure between subjects with SCTD and their matched normal controls. Subjects with SCTD have a significantly different heart rate profile during rest, exercise, and recovery.

  1. Heart Rate and Energy Expenditure in Division I Field Hockey Players During Competitive Play.

    Science.gov (United States)

    Sell, Katie M; Ledesma, Allison B

    2016-08-01

    Sell, KM and Ledesma, AB. Heart rate and energy expenditure in Division I field hockey players during competitive play. J Strength Cond Res 30(8): 2122-2128, 2016-The purpose of this study was to quantify energy expenditure and heart rate data for Division I female field hockey players during competitive play. Ten female Division I collegiate field hockey athletes (19.8 ± 1.6 years; 166.4 ± 6.1 cm; 58.2 ± 5.3 kg) completed the Yo-Yo intermittent endurance test to determine maximal heart rate. One week later, all subjects wore a heart rate monitor during a series of 3 matches in an off-season competition. Average heart rate (AvHR), average percentage of maximal heart rate (AvHR%), peak exercise heart rate (PExHR), and percentage of maximal heart rate (PExHR%), time spent in each of the predetermined heart rate zones, and caloric expenditure per minute of exercise (kcalM) were determined for all players. Differences between positions (backs, midfielders, and forwards) were assessed. No significant differences in AvHR, AvHR%, PExHR, PExHR%, and %TM were observed between playing positions. The AvHR% and PExHR% for each position fell into zones 4 (77-93% HRmax) and 5 (>93% HRmax), respectively, and significantly more time was spent in zone 4 compared with zones 1, 2, 3, and 5 across all players (p ≤ 0.05). The kcalM reflected very heavy intensity exercise. The results of this study will contribute toward understanding the sport-specific physiological demands of women's field hockey and has specific implications for the duration and schedule of training regimens.

  2. Effect of Exercise Testing on Short-term Heart Rate Variability in Patients with Coronary Heart Disease

    DEFF Research Database (Denmark)

    Niu, Hui-Yan; Zhang, Dai-Fu; Liang, Bo

    2005-01-01

    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...

  3. Real-time Continuous Assessment Method for Mental and Physiological Condition using Heart Rate Variability

    Science.gov (United States)

    Yoshida, Yutaka; Yokoyama, Kiyoko; Ishii, Naohiro

    It is necessary to monitor the daily health condition for preventing stress syndrome. In this study, it was proposed the method assessing the mental and physiological condition, such as the work stress or the relaxation, using heart rate variability at real time and continuously. The instantanuous heart rate (HR), and the ratio of the number of extreme points (NEP) and the number of heart beats were calculated for assessing mental and physiological condition. In this method, 20 beats heart rate were used to calculate these indexes. These were calculated in one beat interval. Three conditions, which are sitting rest, performing mental arithmetic and watching relaxation movie, were assessed using our proposed algorithm. The assessment accuracies were 71.9% and 55.8%, when performing mental arithmetic and watching relaxation movie respectively. In this method, the mental and physiological condition was assessed using only 20 regressive heart beats, so this method is considered as the real time assessment method.

  4. Heart rate changes during the Valsalva maneuver in patients with isolated aortic insufficiency

    Directory of Open Access Journals (Sweden)

    Navarro A.E.

    1997-01-01

    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

  5. Prolonged Sitting is Associated with Attenuated Heart Rate Variability during Sleep in Blue-Collar Workers

    Directory of Open Access Journals (Sweden)

    David M Hallman

    2015-11-01

    Full Text Available Prolonged sitting is associated with increased risk for cardiovascular diseases and mortality. However, research into the physiological determinants underlying this relationship is still in its infancy. The aim of the study was to determine the extent to which occupational and leisure-time sitting are associated with nocturnal heart rate variability (HRV in blue-collar workers. The study included 138 blue-collar workers (mean age 45.5 (SD 9.4 years. Sitting-time was measured objectively for four days using tri-axial accelerometers (Actigraph GT3X+ worn on the thigh and trunk. During the same period, a heart rate monitor (Actiheart was used to sample R-R intervals from the electrocardiogram. Time and frequency domain indices of HRV were only derived during nighttime sleep, and used as markers of cardiac autonomic modulation. Regression analyses with multiple adjustments (age, gender, body mass index, smoking, job-seniority, physical work-load, influence at work, and moderate-to-vigorous physical activity were used to investigate the association between sitting time and nocturnal HRV. We found that occupational sitting-time was negatively associated (p < 0.05 with time and frequency domain HRV indices. Sitting-time explained up to 6% of the variance in HRV, independent of the covariates. Leisure-time sitting was not significantly associated with any HRV indices (p > 0.05. In conclusion, objectively measured occupational sitting-time was associated with reduced nocturnal HRV in blue-collar workers. This indicates an attenuated cardiac autonomic regulation with increasing sitting-time at work regardless of moderate-to-vigorous physical activity. The implications of this association for cardiovascular disease risk warrant further investigation via long-term prospective studies and intervention studies.

  6. Blood pressure and heart rate variability analysis of orthostatic challenge in normal human pregnancies.

    Science.gov (United States)

    Heiskanen, Nonna; Saarelainen, Heli; Valtonen, Pirjo; Lyyra-Laitinen, Tiina; Laitinen, Tomi; Vanninen, Esko; Heinonen, Seppo

    2008-11-01

    The aim of the present study was to evaluate pregnancy-related changes in autonomic regulatory functions in healthy subjects. We studied cardiovascular autonomic responses to head-up tilt (HUT) in 28 pregnant women during the third trimester of pregnancy and 3 months after parturition. The maternal ECG and non-invasive beat-to-beat blood pressure were recorded in the horizontal position (left-lateral position) and during HUT in the upright position. Stroke volume was assessed from blood pressure signal by using the arterial pulse contour method. Heart rate variability (HRV) was analysed in frequency domain, and baroreflex sensitivity by the cross-spectral and the sequence methods. In the horizontal position, all frequency components of HRV were lower during pregnancy than 3 months after parturition (P pregnancy had no influence on normalized low frequency and high frequency powers. During pregnancy haemodynamics was well balanced with only minor changes in response to postural change while haemodynamic responses to HUT were more remarkable after parturition. In pregnant women HRV and especially its very low frequency component increased in response to HUT, whereas at 3 months after parturition the direction of these changes was opposite. Parasympathetic deactivation towards term is likely to contribute to increased heart rate and cardiac output at rest, whereas restored sympathetic modulation with modest responses may contribute stable peripheral resistance and sufficient placental blood supply under stimulated conditions. It is important to understand cardiovascular autonomic nervous system and haemodynamic control in normal pregnancy before being able to judge whether they are dysregulated in complicated pregnancies.

  7. External Counterpulsation Increases Beat-to-Beat Heart Rate Variability in Patients with Ischemic Stroke.

    Science.gov (United States)

    Xiong, Li; Tian, Ge; Wang, Li; Lin, Wenhua; Chen, Xiangyan; Leung, Thomas Wai Hong; Soo, Yannie Oi Yan; Wong, Lawrence Ka Sing

    2017-07-01

    External counterpulsation (ECP) is a noninvasive method used to augment cerebral perfusion in ischemic stroke. However, the response of beat-to-beat heart rate variability (HRV) in patients with ischemic stroke during ECP remains unknown. Forty-eight patients with unilateral ischemic stroke at the subacute stage and 14 healthy controls were recruited. Beat-to-beat heart rate before, during, and after ECP was monitored. The frequency components of HRV were calculated using power spectral analysis. Very low frequency (VLF; <.04 Hz), low frequency (LF; .04-.15 Hz), high frequency (HF; .15-.40 Hz), total power spectral density (TP; <.40 Hz), and LF/HF ratio were calculated. In stroke patients, although there were no statistical differences in all of the HRV components, the HRV at VLF showed a trend of increase during ECP compared with baseline in the left-sided stroke patients (P = .083). After ECP, the HRV at LF and TP remained higher than baseline in the right-sided stroke patients (LF, 209.4 versus 117.9, P = .050; TP, 1275.6 versus 390.2, P = .017, respectively). Besides, the HRV at TP also increased after ECP compared with baseline in the left-sided stroke patients (563.0 versus 298.3, P = .029). Irrespective of the side of the ischemia, patients showed an increased beat-to-beat HRV after ECP. Additionally, sympathetic and parasympathetic cardiac modulations were increased after ECP in patients after right-sided subacute stroke. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  8. Diagnostic quality of dual-source coronary CT exams performed without heart rate control: importance of obesity and heart rate on image quality

    Science.gov (United States)

    Zimmerman, Stefan L.; Kral, Brian G.; Fishman, Elliot K.

    2014-01-01

    Objectives For dual source cardiac CTs without heart rate control, the influence of body habitus on quality is uncertain. We evaluated study quality across a range of heart rates (HR) and body size. Methods 160 subjects were randomly selected for four HR groups [quality was scored on a 3 point scale (1=non-diagnostic, 2=diagnostic, 3=excellent). Results 99% of coronaries were diagnostic quality. Six vessels were non-diagnostic, mostly due to motion. Nondiagnostic or diagnostic scores (quality but 6% of vessels in overweight and 17% in obese subjects had diagnostic scores quality cardiac CT exams can be obtained without premedication regardless of body size. PMID:25032805

  9. Skeletal muscle signaling and the heart rate and blood pressure response to exercise

    DEFF Research Database (Denmark)

    Mortensen, Stefan P; Svendsen, Jesper H; Ersbøll, Mads

    2013-01-01

    Endurance training lowers heart rate and blood pressure responses to exercise, but the mechanisms and consequences remain unclear. To determine the role of skeletal muscle for the cardioventilatory response to exercise, 8 healthy young men were studied before and after 5 weeks of 1-legged knee......-extensor training and 2 weeks of deconditioning of the other leg (leg cast). Hemodynamics and muscle interstitial nucleotides were determined during exercise with the (1) deconditioned leg, (2) trained leg, and (3) trained leg with atrial pacing to the heart rate obtained with the deconditioned leg. Heart rate...

  10. A handle electrode system for measuring heart rate while riding a bicycle.

    Science.gov (United States)

    Watanabe, Masutaka; Tsukamoto, Sosuke; Hoshino, Hiroshi

    2008-01-01

    In this paper, a handle-electrode system is proposed for obtaining the heart rate of a user while riding a bicycle. The system was designed to measure the user's heart rate by only gripping the handle of a bicycle. Three electrodes made from conductive cloth were adhered to the handle. A method detecting heart-rate from the obtained electrocardiogram was also proposed. To assess the applicability of the proposed system, a simple experiment was performed. The experiment was performed in four conditions of road surfaces; lawn, asphalt, a tiled, and an uneven road. Experimental result suggests that the proposed system can be useful for obtaining R waves while riding a bicycle.

  11. Heart Rate and Treatment Effect in Children with Disruptive Behavior Disorders

    Science.gov (United States)

    Stadler, Christina; Grasmann, Dorte; Fegert, Jorg M.; Holtmann, Martin; Poustka, Fritz; Schmeck, Klaus

    2008-01-01

    Objective: To examine whether children with disruptive behavior disorders (DBDs; hyperkinetic conduct disorder, conduct disorder, hyperkinetic disorder) characterized by low heart rate profit less from an intensive cognitive behavioral intervention aimed at reducing impulsive, oppositional and aggressive behavior problems. Method: Basal heart rate…

  12. Nonlinear analysis of heart rate variability in patients with eating disorders

    NARCIS (Netherlands)

    Vigo, Daniel E.; Castro, Mariana N.; Dorpinghaus, Andrea; Weidema, Hylke; Cardinali, Daniel P.; Siri, Leonardo Nicola; Rovira, Bernardo; Fahrer, Rodolfo D.; Nogues, Martin; Leiguarda, Ramon C.; Guinjoan, Salvador M.

    2008-01-01

    Patients with anorexia nervosa or bulimia nervosa often have signs of autonomic dysfunction potentially deleterious to the heart. The aim of this study was to ascertain the nonlinear properties of heart rate variability in patients with eating disorders. A group of 33 women with eating disorders (14

  13. Spectral analysis of time series of events: effect of respiration on heart rate in neonates

    International Nuclear Information System (INIS)

    Van Drongelen, Wim; Williams, Amber L; Lasky, Robert E

    2009-01-01

    Certain types of biomedical processes such as the heart rate generator can be considered as signals that are sampled by the occurring events, i.e. QRS complexes. This sampling property generates problems for the evaluation of spectral parameters of such signals. First, the irregular occurrence of heart beats creates an unevenly sampled data set which must either be pre-processed (e.g. by using trace binning or interpolation) prior to spectral analysis, or analyzed with specialized methods (e.g. Lomb's algorithm). Second, the average occurrence of events determines the Nyquist limit for the sampled time series. Here we evaluate different types of spectral analysis of recordings of neonatal heart rate. Coupling between respiration and heart rate and the detection of heart rate itself are emphasized. We examine both standard and data adaptive frequency bands of heart rate signals generated by models of coupled oscillators and recorded data sets from neonates. We find that an important spectral artifact occurs due to a mirror effect around the Nyquist limit of half the average heart rate. Further we conclude that the presence of respiratory coupling can only be detected under low noise conditions and if a data-adaptive respiratory band is used

  14. Exposure to Fine Particulate Matter Leads to Rapid Heart Rate Variability Changes

    Directory of Open Access Journals (Sweden)

    Michael Riediker

    2018-01-01

    Full Text Available Introduction: Heart Rate Variability (HRV reflects the adaptability of the heart to internal and external stimuli. Reduced HRV is a predictor of post-infarction mortality. We previously found in road maintenance workers HRV-increases several hours after exposure to fine particulate matter (PM2.5. This seemed to conflict with studies where PM-exposure acutely reduced HRV. We therefore assessed whether time from exposure to HRV-assessment could explain the differences observed.Methods: On five non-consecutive days, workers carried nephelometers providing 1-min-interval PM2.5-exposure. Five-min HRV-intervals of SDNN (Standard Deviation of Normal to Normal beat intervals and pNN50 (Percentage of the interval differences exceeding 50 ms were extracted from 24-h electrocardiograms (ECGs. Following 60 min PM2.5-exposure, changes in HRV-parameters were assessed during 120-min visually and by regression analysis with control for time at work, at home, and during the night using autoregressive integrating moving average (ARIMA models to account for autocorrelation of the time-series. Additional controls included changing the time windows and including body mass index (BMI and age in the models.Result: Pattern analysis of 12,669 data points showed high modulation of mean, standard deviation (SD, and time trend of HRV (SDNN and pNN50 at low, and much reduced modulation at high PM2.5-exposures. The time trend following exposure was highly symmetrical, resembling a funnel plot. Regression analysis showed significant associations of decreasing SDNN and pNN50 (average, SD, and absolute value of time trend with increasing PM2.5-exposure, which remained significant when controlling for activity phases. Changing time windows did not change the pattern of response. Including BMI and age did not change the results.Conclusions: The reduced modulation of HRV following PM2.5-exposure is striking. It suggests strong interference with homeostatic controls. Such an

  15. Embryos in the fast lane: high-temperature heart rates of turtles decline after hatching.

    Directory of Open Access Journals (Sweden)

    Wei-Guo Du

    Full Text Available In ectotherms such as turtles, the relationship between cardiovascular function and temperature may be subject to different selective pressures in different life-history stages. Because embryos benefit by developing as rapidly as possible, and can "afford" to expend energy to do so (because they have access to the yolk for nutrition, they benefit from rapid heart (and thus, developmental rates. In contrast, hatchlings do not have a guaranteed food supply, and maximal growth rates may not enhance fitness--and so, we might expect a lower heart rate, especially at high temperatures where metabolic costs are greatest. Our data on two species of emydid turtles, Chrysemys picta, and Graptemys pseudogeographica kohnii, support these predictions. Heart rates of embryos and hatchlings were similar at low temperatures, but heart rates at higher temperatures were much greater before than after hatching.

  16. Assessment of autonomic function after acute spinal cord injury using heart rate variability analyses

    DEFF Research Database (Denmark)

    Malmqvist, Lasse; Biering-Sørensen, Tor; Bartholdy, Kim

    2015-01-01

    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 rate....... CONCLUSIONS: The rise in SDANN in the incomplete C1-T5 patients could be due to spontaneous functional recovery caused by synaptic plasticity or remodelling of damaged axons. That the autonomic nervous system function differs between C1-C8, T1-T5 and T6-T12 patients suggest that the sympathovagal balance...

  17. Fast Simulation of Mechanical Heterogeneity in the Electrically Asynchronous Heart Using the MultiPatch Module.

    Directory of Open Access Journals (Sweden)

    John Walmsley

    2015-07-01

    Full Text Available Cardiac electrical asynchrony occurs as a result of cardiac pacing or conduction disorders such as left bundle-branch block (LBBB. Electrically asynchronous activation causes myocardial contraction heterogeneity that can be detrimental for cardiac function. Computational models provide a tool for understanding pathological consequences of dyssynchronous contraction. Simulations of mechanical dyssynchrony within the heart are typically performed using the finite element method, whose computational intensity may present an obstacle to clinical deployment of patient-specific models. We present an alternative based on the CircAdapt lumped-parameter model of the heart and circulatory system, called the MultiPatch module. Cardiac walls are subdivided into an arbitrary number of patches of homogeneous tissue. Tissue properties and activation time can differ between patches. All patches within a wall share a common wall tension and curvature. Consequently, spatial location within the wall is not required to calculate deformation in a patch. We test the hypothesis that activation time is more important than tissue location for determining mechanical deformation in asynchronous hearts. We perform simulations representing an experimental study of myocardial deformation induced by ventricular pacing, and a patient with LBBB and heart failure using endocardial recordings of electrical activation, wall volumes, and end-diastolic volumes. Direct comparison between simulated and experimental strain patterns shows both qualitative and quantitative agreement between model fibre strain and experimental circumferential strain in terms of shortening and rebound stretch during ejection. Local myofibre strain in the patient simulation shows qualitative agreement with circumferential strain patterns observed in the patient using tagged MRI. We conclude that the MultiPatch module produces realistic regional deformation patterns in the asynchronous heart and that

  18. Performance limits of ICA-based heart rate identification techniques in imaging photoplethysmography

    International Nuclear Information System (INIS)

    Mannapperuma, Kavan; Holton, Benjamin D; Lesniewski, Peter J; Thomas, John C

    2015-01-01

    Imaging photoplethysmography is a relatively new technique for extracting biometric information from video images of faces. This is useful in non-invasive monitoring of patients including neonates or the aged, with respect to sudden infant death syndrome, sleep apnoea, pulmonary disease, physical or mental stress and other cardio-vascular conditions. In this paper, we investigate the limits of detection of the heart rate (HR) while reducing the video quality. We compare the performance of three independent component analysis (ICA) methods (JADE, FastICA, RADICAL), autocorrelation with signal conditioning techniques and identify the most robust approach. We discuss sources of increasing error and other limiting conditions in three situations of reduced signal-to-noise ratio: one where the area of the analyzed face is decreased from 100 to 5%, another where the face area is progressively re-sampled down to a single RGB pixel and one where the HR signal is severely reduced with respect to the boundary noise. In most cases, the cardiac pulse rate can be reliably and accurately detected from videos containing only 5% facial area or from a face occupying just 4 pixels or containing only 5% of the facial HR modulation. (paper)

  19. Effects of heart rate on myocardial thallium-201 uptake and clearance

    International Nuclear Information System (INIS)

    Nordrehaug, J.E.; Danielsen, R.; Vik-Mo, H.

    1989-01-01

    The effects of heart rate on the myocardial uptake and clearance of 201 Tl were studied prospectively in seven healthy men, mean age 43 +/- 7 (s.d.) yr. Initial and delayed (3 hr) thallium images were obtained in three views after three bicycle exercise tests: to maximal, 80% and 60% of predicted maximal heart rate. The mean of three views initial myocardial 201 Tl uptake was higher at maximal than at both 80% and 60% of predicted maximal heart rate, being 81% (p less than 0.01) and 60% (p less than 0.01) of maximal activity, respectively. The myocardial activity in the delayed images was identical. There was a linear relationship between heart rate and the initial myocardial activity, r = 0.86 (p less than 0.001). The mean (range) 201 Tl clearance was 58% (51-65), 47% (34-56), and 34% (22-49) (all differences p less than 0.01), respectively. Concordance among the three individual views in estimating clearance was best for the highest exercise level. There was a linear relationship between heart rate and clearance, r = 0.80 (p less than 0.001). Clearance was altered by only 1.67 x 10%/heart bpm (0.024 hr/heart beat). Clearance in the liver, spleen and lungs increased at submaximal exercise levels. Thus, a linear relationship between heart rate and clearance is the result of changes in the initial exercise myocardial 201 Tl activity. Submaximal exercise may reduce reproducibility of clearance estimation, and the change of myocardial clearance with heart rate seems less than previously suggested

  20. Heart rate and rate of oxygen consumption of exercising macaroni penguins.

    Science.gov (United States)

    Green, J A; Butler, P J; Woakes, A J; Boyd, I L; Holder, R L

    2001-02-01

    Twenty-four macaroni penguins (Eudyptes chrysolophus) from three groups, breeding males (N=9), breeding females (N=9) and moulting females (N=6), were exercised on a variable-speed treadmill. Heart rate (fH) and mass-specific rate of oxygen consumption (sVO2) were recorded from the animals, and both fh and sVO2 were found to increase linearly with increasing treadmill speed. A linear regression equation described the relationship between fh and sVO2 for each individual. There were no significant differences in these regressions between breeding and moulting females. There were significant differences in these relationships between all females and breeding males. fH and s VO2 were recorded from five of these animals for a total of 24 h. When fh was used to predict sVO2 for the 24 h period using the derived regressions, the estimate was not significantly different from the measured values, with an average error of -2.1 %. When fh was used to predict sVO2 for the 5 min intervals used for the calibration in all 24 birds, the estimate was not significantly different from the observed values, and the average error was only +0.47 %. Since the fH/sVO2 relationship was the same during periods of the annual cycle when the animals were inactive/fasting and active/foraging, it seems reasonable that, as long as sex differences are taken into account, fh can be used to predict the metabolic rates of free-ranging macaroni penguins all year round.

  1. Rate of coronary flow adaptation in response to changes in heart rate before and during anesthesia for coronary artery surgery

    NARCIS (Netherlands)

    van Wezel, H. B.; Kal, J. E.; Vergroesen, I.; Vroom, M. B.; de Graaf, R.; Dankelman, J.; Porsius, M.; Spaan, J. A.

    1996-01-01

    BACKGROUND: The rate of adaptation of coronary blood flow in response to stepwise changes in heart rate (HR) has been extensively studied in dogs and goats to improve our understanding of the dynamics of coronary regulation processes and their pathophysiology and to obtain time constants for

  2. The Effects of Musical Auditory Stimulation of Different Intensities on Geometric Indices of Heart Rate Variability.

    Science.gov (United States)

    do Amaral, Joice Anaize Tonon; Guida, Heraldo Lorena; Vanderlei, Franciele Marques; Garner, David Matthew; de Abreu, Luiz Carlos; Valenti, Vitor Engracia

    2015-01-01

    Music has been proven to promote changes in cardiac autonomic modulation. However, it is not clear whether the effects of the auditory stimulation on heart rate variability (HRV) are dependent on its intensity. The study intended to investigate the acute effects on the geometric HRV indices of auditory stimulation with heavy metal and baroque music using different intensities of auditory stimulation. The study was a nonrandomized, clinical trial. The study was conducted at the facility of the Faculty of Sciences of the São Paulo State University, on the campus in Marilia, Brazil. Participants were 24 healthy women aged between 18 and 27 y. HRV was recorded for each participant for 10 min at rest. Subsequently, participants were exposed to baroque or heavy metal music through an earphone. They were exposed to 3 equivalent sound levels-60-70 decibels (dB), 70-80 dB, and 80-90 dB-for 5 min in each intensity range. After the first session of baroque or heavy metal music, participants rested for an additional 5 min. Then they were exposed to the other musical style. The first style played for each musical period was randomly selected for all individuals and then the other style would be played automatically for the second session. The HRV analysis was performed using the following geometrical methods: (1) the triangular index (RRtri), (2) the triangular interpolation of the RR interval histogram (TINN), and (3) the Poincaré plot, using SD1-the standard deviation of the instantaneous variability of the beat-to beat heart rate (HR), SD2-the standard deviation of the long-term, continuous, RR interval variability, and the SD1/SD2 ratio-the ratio between the short- and long-term variations among the RR intervals. The classic baroque music by Johann Pachelbel, "Canon in D Major," did not induce significant changes in the geometric indices of HRV at 60-70 dB, 70-80 dB, or 80-90 dB. However, auditory stimulation with heavy metal music, using "Heavy Metal Universe" by Gamma

  3. Respiratory muscle strength effect on linear and nonlinear heart rate variability parameters in COPD patients

    Directory of Open Access Journals (Sweden)

    Goulart CL

    2016-07-01

    Full Text Available Cássia Da Luz Goulart,1 Julio Cristiano Simon,1 Paloma De Borba Schneiders,1 Elisabete Antunes San Martin,1 Ramona Cabiddu,2 Audrey Borghi-Silva,2 Renata Trimer,2 Andréa Lúcia Gonçalves da Silva1 1Course of Physiotherapy, Department of Health and Physical Education, University of Santa Cruz do Sul (UNISC, Santa Cruz do Sul, Rio Grande do Sul, Brazil; 2Cardiopulmonary Physiotherapy Laboratory, Nucleus of Research in Physical Exercise, Federal University of São Carlos (UFSCar, São Carlos, São Paulo, Brazil Introduction: Chronic obstructive pulmonary disease (COPD is recognized as a multisystemic inflammatory disease associated with extrapulmonary comorbidities, including respiratory muscle weakness and cardiovascular and cardiac autonomic regulation disorders. We investigated whether alterations in respiratory muscle strength (RMS would affect cardiac autonomic modulation in COPD patients. Methods: This study was a cross-sectional study done in ten COPD patients affected by moderate to very severe disease. The heart rate variability (HRV signal was recorded using a Polar cardiofrequencimeter at rest in the sitting position (10 minutes and during a respiratory sinus arrhythmia maneuver (RSA-M; 4 minutes. Linear analysis in the time and frequency domains and nonlinear analysis were performed on the recorded signals. RMS was assessed using a digital manometer, which provided the maximum inspiratory pressure (Pimax and the maximum expiratory pressure (Pemax. Results: During the RSA-M, patients presented an HRV power increase in the low-frequency band (LFnu (46.9±23.7 vs 75.8±27.2; P=0.01 and a decrease in the high-frequency band (HFnu (52.8±23.5 vs 24.0±27.0; P=0.01 when compared to the resting condition. Significant associations were found between RMS and HRV spectral indices: Pimax and LFnu (r=-0.74; P=0.01; Pimax and HFnu (r=0.74; P=0.01; Pemax and LFnu (r=-0.66; P=0.01; Pemax and HFnu (r=0.66; P=0.03; between Pemax and sample entropy (r

  4. Heart rate variability and Omega-3 Index in euthymic patients with bipolar disorders.

    Science.gov (United States)

    Voggt, A; Berger, M; Obermeier, M; Löw, A; Seemueller, F; Riedel, M; Moeller, H J; Zimmermann, R; Kirchberg, F; Von Schacky, C; Severus, E

    2015-02-01

    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; Pheart 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.

  5. An EEMD-PCA approach to extract heart rate, respiratory rate and respiratory activity from PPG signal.

    Science.gov (United States)

    Motin, Mohammod Abdul; Karmakar, Chandan Kumar; Palaniswami, Marimuthu

    2016-08-01

    The pulse oximeter's photoplethysmographic (PPG) signals, measure the local variations of blood volume in tissues, reflecting the peripheral pulse modulated by cardiac activity, respiration and other physiological effects. Therefore, PPG can be used to extract the vital cardiorespiratory signals like heart rate (HR), respiratory rate (RR) and respiratory activity (RA) and this will reduce the number of sensors connected to the patient's body for recording vital signs. In this paper, we propose an algorithm based on ensemble empirical mode decomposition with principal component analysis (EEMD-PCA) as a novel approach to estimate HR, RR and RA simultaneously from PPG signal. To examine the performance of the proposed algorithm, we used 45 epochs of PPG, electrocardiogram (ECG) and respiratory signal extracted from the MIMIC database (Physionet ATM data bank). The ECG and capnograph based respiratory signal were used as the ground truth and several metrics such as magnitude squared coherence (MSC), correlation coefficients (CC) and root mean square (RMS) error were used to compare the performance of EEMD-PCA algorithm with most of the existing methods in the literature. Results of EEMD-PCA based extraction of HR, RR and RA from PPG signal showed that the median RMS error (quartiles) obtained for RR was 0 (0, 0.89) breaths/min, for HR was 0.62 (0.56, 0.66) beats/min and for RA the average value of MSC and CC was 0.95 and 0.89 respectively. These results illustrated that the proposed EEMD-PCA approach is more accurate in estimating HR, RR and RA than other existing methods.

  6. Heart rate variability predicts 30-day all-cause mortality in intensive ...

    African Journals Online (AJOL)

    HRV), has shown promise in predicting clinically important outcomes in the critical care setting; however, there is debate concerning its utility. ... Keywords: APACHE II, autonomic nervous system, critical care, heart rate variability, mortality ...

  7. Effects of mindfulness on perceived stress levels and heart rate variability

    OpenAIRE

    Rolph, Gwyneth Wesley

    2017-01-01

    Mindfulness has become increasingly popular as a method for building resilience against stress in both clinical and healthy populations. This study sought to investigate the effects of mindfulness training on perceived levels of stress and heart rate variability in students.

  8. Risk Assessment of Diabetes Mellitus by Chaotic Globals to Heart Rate Variability via Six Power Spectra

    Directory of Open Access Journals (Sweden)

    Garner David M.

    2017-09-01

    Full Text Available Background: The priniciple objective here is to analyze cardiovascular dynamics in diabetic subjects by actions related to heart rate variability (HRV. The correlation of chaotic globals is vital to evaluate the probability of dynamical diseases.

  9. Time-Frequency Analysis of Terahertz Radar Signals for Rapid Heart and Breath Rate Detection

    National Research Council Canada - National Science Library

    Massar, Melody L

    2008-01-01

    We develop new time-frequency analytic techniques which facilitate the detection of a person's heart and breath rates from the Doppler shift the movement of their body induces in a terahertz radar signal...

  10. Inhibition of pericranial muscle activity, respiration, and heart rate enhances auditory sensitivity

    NARCIS (Netherlands)

    Stekelenburg, J.J.; van Boxtel, A.

    2001-01-01

    We investigated whether previously observed inhibition of pericranial electromyographic (EMG) activity, respiration, and heart rate during sensory intake processes improves auditory sensitivity. Participants had to detect weak auditory stimuli. We found that EMG activity in masticatory and lower

  11. Attenuated heart rate response in REM sleep behavior disorder and Parkinson's disease

    DEFF Research Database (Denmark)

    Sorensen, Gertrud Laura; Kempfner, Jacob; Zoetmulder, Marielle

    2012-01-01

    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...... sleep compared with healthy controls. Fourteen and 16 Parkinson's patients with and without rapid‐eye‐movement sleep behavior disorder, respectively, 11 idiopathic rapid‐eye‐movement sleep behavior disorder patients, and 17 control subjects underwent 1 night of polysomnography. The heart rate response...... and the idiopathic rapid‐eye‐movement sleep behavior disorder group. The heart rate response to leg movement was significantly lower in both Parkinson's groups and in the idiopathic rapid‐eye‐movement sleep behavior disorder group compared with the control group. The heart rate response for the idiopathic rapid...

  12. Development and validation of an improved smartphone heart rate acquisition system

    Science.gov (United States)

    Karapetyan, G.; Barseghyan, R.; Sarukhanyan, H.; Agaian, S.

    2015-03-01

    In this paper we propose a robust system for touchless heart rate (HR) acquisition on mobile devices. The application allows monitor heart rate signal during usual mobile device usage such as video watching, games playing, article reading etc. The system is based on algorithm of acquiring heart rate via recording of skin color variations with built-in cameras of mobile device. The signal is acquired from different ROIs of human face, which make it more clear and the amplification of the signal improve the robustness in low lightening conditions. The effectiveness and robustness of the developed system has been demonstrated under different distances from camera source and illumination conditions. The experiments have been done with different mobile devices HRs were collected from 10 subjects, ages 22 to 65, by using the 3 devices. Moreover, we compared the developed method with Food and Drug Administration (FDA) approved sensors and related commercial applications of remote heart rate measurements on mobile devices.

  13. New descriptors of T-wave morphology are independent of heart rate

    DEFF Research Database (Denmark)

    Andersen, Mads Peter; Xue, Joel Q; Graff, Claus

    2008-01-01

    from daytime Holter recordings. Duration parameters (QT, ToTe, TpTe, and others), a number of basic T-wave morphology parameters (amplitude, area, and others) as well as advanced morphology descriptors (asymmetry, flatness, and others) were measured automatically. Heart rate dependence was examined...... by means of analysis of covariance. The results showed clear heart rate dependence for the QT interval (R(2) = 0.53-0.57) and a moderate degree of heart rate dependence for the basic morphology parameters (amplitude, area, and others) (R(2) = 0.17-0.42). Both the advanced T-wave descriptors (asymmetry......T-wave morphology descriptors are sensitive to drug-induced changes and may be a useful addition to the QT interval in cardiac safety trials. Intrasubject heart rate dependence of T-wave morphology was investigated in a sample of 39 healthy individuals. Ten-second electrocardiograms were obtained...

  14. Factors that affect the variability in heart rate during endoscopic retrograde cholangiopancreatography

    DEFF Research Database (Denmark)

    Christensen, Merete; Reinert, Rebekka; Rasmussen, Verner

    2002-01-01

    OBJECTIVE: To find out if drugs, position, and endoscopic manipulation during endoscopic retrograde cholangiopancreatography (ERCP) influence the changes in the variability of heart rate. DESIGN: Single-blind randomised trial. SUBJECTS: 10 volunteers given butyscopolamine, glucagon, or saline...

  15. Effect of pre operative heart rate on post spinal hypotension in obsteric patients

    International Nuclear Information System (INIS)

    Khan, S.; Zahoor, M.U.; Zaid, A.Y.; Buland, K.

    2010-01-01

    The purpose of the study was to determine the association between of preoperative heart rate and post spinal hypotension in women undergoing cesarean section, Two hundred patients undergoing caesarean were included in the study selected on non probability convenience sampling technique, The patients were divided into two groups depending upon their pre operative heart rate. Spinal anesthesia was administered and number of patients developing hypotension was noted. Among 200 patients, who were included in the study; 112 were placed in group A and 88 were placed in group B depending on mean heart rate of 90 beats per minute or less or 91 beats per minute or more respectively. In group A 14 (11.86%) patients developed hypotension where as in group B 28 (31,82%) patients developed hypotension. Pre operative heart rate is significantly associated with post spinal hypotension in obstetric patients undergoing cesarean section. (author)

  16. Modulation of Cardiac Contractility – a New Method in the Treatment of Heart Failure

    Directory of Open Access Journals (Sweden)

    A. A. Petrukhina

    2016-01-01

    Full Text Available The review analyzes new treatment for patients with chronic heart failure (CHF with low ejection fraction – cardiac contractility modulation (CCM. CCM is carried out by supplying electric signals to an absolutely refractory ventricular myocardium, to elicit a positive inotropic effect without increasing myocardial oxygen consumption. These effects are independent on QRS duration; consequently, the therapy might be beneficial for patients who are not candidates for cardiac resynchronization therapy (CRT. It should be noted that the use of CCM treatment of CHF should begin only with maximum active therapy when its efficacy is not enough. It is not an alternative, but complement to the most active treatment of patients. Clinical studies primarily focused on patients with normal QRS duration because the CPT is optimal treatment of patients with prolonged QRS. The article focuses on the prerequisites for the development of the method and discusses the results obtained when evaluating the clinical efficacy and safety of treatment of patients with CHF in randomized clinical trials FIX-HF-3 (n=25, FIX-HF-4 (n=164, FIX-HF-5 (n=428. The total number of patients included into these studies was 617 people. Baseline patient characteristics were similar for all 3 studies. All participants received optimal medical therapy, had a normal QRS duration. All patients were II and III functional class (by NYHA. The studies analyzed the changes in NYHA class, ejection fraction, peak oxygen consumption (VO2, the precursor of brain natriuretic peptide (NT-proBNP level. Quality of life was assessed by the Minnesota questionnaire; the mortality rate was compared with that predicted by MAGGIC scale. CCM therapy had beneficial effect on the survival and quality of life in patients with CHF. However, more data is needed to assess long-term effects of the CCM therapy.

  17. EFFECT OF FUROSEMIDE AND TORASEMIDE ON HEART RATE VARIABILITY AND VENTRICULAR RHYTHM DISORDERS IN PATIENTS WITH CHRONIC HEART FAILURE COMPLICATING ISCHEMIC HEART DISEASE: COMPARATIVE NONRANDOMIZED STUDY

    Directory of Open Access Journals (Sweden)

    H. H. Shugushev

    2010-01-01

    Full Text Available Aim. To study effect of diuretic therapy with furosemide and torasemide on heart rate variability (HRV and frequency of ventriclar rhythm disorders in patients with chronic heart failure (CHF complicating ischemic heart disease (IHD.Material and methods. Patients (n=107 with CHF III-IV functional class (NYHA complicating IHD were examined. The first group of patients received furosemide, 20-60 mg QD (n=52, the second group received torasemide, 5-20 mg QD (n=55. Analysis of heart rhythm disorders and the basic HRV indicators was performed by ECG 10-minute recordings initially and after 10 days of therapy.Results. Decrease in time and spectral HRV parameters and increase in daily number of ventricular extrasystoles was found in furosemide treated patients. Improvement of HRV parameters and reduction of daily number of ventricular rhythm disorders was found torasemide treated patients.Conclusion. Torasemide therapy improves an autonomic regulation of heart rhythm and leads to the reduction of ventricular heart rhythm disorders in patients with CHF complicating IHD.

  18. A prospective study of heart rate and externalising behaviours in young children.

    Science.gov (United States)

    Dierckx, Bram; Kok, Rianne; Tulen, Joke H M; Jaddoe, Vincent W; Hofman, Albert; Verhulst, Frank C; Bakermans-Kranenburg, Marian J; van Ijzendoorn, Marinus H; Tiemeier, Henning

    2014-04-01

    Low heart rate predicts externalising and delinquent behaviour in adults, adolescents and school-age children. In younger children the evidence is less clear. Moreover, the specificity of the relation between the autonomic nervous system and different forms of externalising behaviour is uncertain. We investigated the longitudinal relation between resting mean heart rate and different externalising behaviours. In 412 children of the Generation R Study, we measured resting mean heart rate at 14 months. At 3 years, child problem behaviour was assessed by the mother with the Child Behavior Checklist. In a gift delay task, we observed whether children were compliant and whether they lied about their noncompliance. The association of heart rate with behaviour was contrasted with the effect of harsh parenting. In our main analysis, we examined the association between heart rate and reported and observed child behaviour. For comparison, the association of heart rate with behaviour was contrasted with the effect of harsh parenting. Mean heart rate was positively associated with Anxious/Depressed scale scores (β = .1, 95% CI = 0.01; 0.2, p = .04), but not with Aggressive Behaviour (β = .02; 95% CI = −0.1; 0.1, p = .8) nor Attention Problem scale scores (β = .08, 95% CI = −0.3; 0.5, p = .8). We could not demonstrate an association between mean heart rate and noncompliance during the gift delay task (OR = 1.14, 95% CI = 0.9; 1.1, p = .2), but lower heart rate predicted higher odds of the child lying (OR = 0.56, 95% CI = 0.3; 0.9, p = .03). In contrast, harsh parenting was associated with mother-reported Aggressive Behaviour (β = .7, 95% CI = 0.4; 0.9, p Problems (β = .2, 95% CI = 0.1; 0.3, p < .001), but not with observed lying (OR = 1.03, 95% CI = 0.8; 1.4, p = .8). Lower resting mean heart rate at age 14 months predicts low anxiety symptoms and higher odds of lying at age 3 years. Low resting mean heart rate may be less an indicator of early childhood aggression

  19. Nocturnal variations in peripheral blood flow, systemic blood pressure, and heart rate in humans

    DEFF Research Database (Denmark)

    Sindrup, J H; Kastrup, J; Christensen, H

    1991-01-01

    Subcutaneous adipose tissue blood flow rate, together with systemic arterial blood pressure and heart rate under ambulatory conditions, was measured in the lower legs of 15 normal human subjects for 12-20 h. The 133Xe-washout technique, portable CdTe(Cl) detectors, and a portable data storage unit...... were used for measurement of blood flow rates. An automatic portable blood pressure recorder and processor unit was used for measurement of systolic blood pressure, diastolic blood pressure, and heart rate every 15 min. The change from upright to supine position at the beginning of the night period...... was associated with a 30-40% increase in blood flow rate and a highly significant decrease in mean arterial blood pressure and heart rate (P less than 0.001 for all). Approximately 100 min after the subjects went to sleep an additional blood flow rate increment (mean 56%) and a simultaneous significant decrease...

  20. Changes of heart rate variability and baroreflex sensitivity in patients soon after orthotopic heart transplantation

    Czech Academy of Sciences Publication Activity Database

    Fráňa, P.; Kára, T.; Souček, M.; Halámek, Josef; Řiháček, I.; Orban, O.; Toman, J.; Bartosikova, L.; Nečas, J.; Dzurova, J.

    2002-01-01

    Roč. 20, č. 4 (2002), s. S293 ISSN 0263-6352. [Scientific meeting of the international society of hypertension - european meeting on hypertension. 23.06.2002-27.06.2002, Praha] R&D Projects: GA ČR GA102/00/1262; GA ČR GA102/02/1339 Institutional research plan: CEZ:AV0Z2065902 Keywords : baroreflex * heart transplantation * ANS Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  1. Diurnal variations in arousal: a naturalistic heart rate study in children with ADHD.

    Science.gov (United States)

    Imeraj, Lindita; Antrop, Inge; Roeyers, Herbert; Deschepper, Ellen; Bal, Sarah; Deboutte, Dirk

    2011-08-01

    Previous studies suggest an altered circadian regulation of arousal in children with attention-deficit hyperactivity disorder (ADHD) as measured by activity, circadian preference, and sleep-wake patterns. Although heart rate is an important measure to evaluate arousal profiles, to date it is unknown whether 24-h heart rate patterns differentiate between children with and without ADHD. In this study, 24-h heart rate data were collected in 30 non-medicated children with ADHD (aged 6-11) and 30 sex-, class-, and age-matched normal controls in their naturalistic home and school setting, during 5 days. Simultaneously, 24-h activity patterns were registered. Confounding effects of demographic variables (e.g., age, sex, BMI, pubertal stage) and comorbid internalizing and externalizing problems on heart rate levels were additionally assessed. Longitudinal analysis showed that heart rate levels were overall higher in the ADHD group (p < 0.01)--with the largest effects during afternoon and night--in a model controlling for age. Other factors did not significantly contribute to variations in heart rate levels. Compared to controls, children with ADHD showed higher activity levels during daytime (especially early afternoon), but not during nighttime (p < 0.05). Post hoc analyses showed that environmental effects might influence daytime variations. Findings suggest an autonomic imbalance in children with ADHD as compared to controls, with higher heart rate levels in the ADHD group. Nighttime tachycardia in this group could not be explained by nighttime activity levels or comorbid externalizing/internalizing problems. Further research on autonomic functioning in ADHD is recommended because of the major impact of higher resting heart rate on health outcomes.

  2. Effect of heart rate and myocardial contractile force on coronary resistance.

    OpenAIRE

    Saito, Daiji; Ueeda, Masayuki; Hina, Kazuyoshi; Watanabe, Hirofumi; Mima, Tsutomu; Hasui, Masahiro; Yamada, Nobuyuki; Haraoka, Shoichi; Tsuji, Takao

    1988-01-01

    The effect of the heart rate and myocardial contractile force on the extravascular resistance to blood flow of the left anterior descending coronary artery (LAD) was evaluated in 15 mongrel dogs anesthetized with sodium pentobarbital. The LAD was maximally dilated by intracoronary infusion of adenosine, which precluded the influence of vasomotor tone. Increases in the heart rate and myocardial contractile force decreased coronary blood flow in the absence of a change in coronary perfusion pre...

  3. Parasympathetic neural activity accounts for the lowering of exercise heart rate at high altitude

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Calbet, J A; Rådegran, G

    2001-01-01

    In chronic hypoxia, both heart rate (HR) and cardiac output (Q) are reduced during exercise. The role of parasympathetic neural activity in lowering HR is unresolved, and its influence on Q and oxygen transport at high altitude has never been studied.......In chronic hypoxia, both heart rate (HR) and cardiac output (Q) are reduced during exercise. The role of parasympathetic neural activity in lowering HR is unresolved, and its influence on Q and oxygen transport at high altitude has never been studied....

  4. Design of a heart rate controller for treadmill exercise using a recurrent fuzzy neural network.

    Science.gov (United States)

    Lu, Chun-Hao; Wang, Wei-Cheng; Tai, Cheng-Chi; Chen, Tien-Chi

    2016-05-01

    In this study, we developed a computer controlled treadmill system using a recurrent fuzzy neural network heart rate controller (RFNNHRC). Treadmill speeds and inclines were controlled by corresponding control servo motors. The RFNNHRC was used to generate the control signals to automatically control treadmill speed and incline to minimize the user heart rate deviations from a preset profile. The RFNNHRC combines a fuzzy reasoning capability to accommodate uncertain information and an artificial recurrent neural network learning process that corrects for treadmill system nonlinearities and uncertainties. Treadmill speeds and inclines are controlled by the RFNNHRC to achieve minimal heart rate deviation from a pre-set profile using adjustable parameters and an on-line learning algorithm that provides robust performance against parameter variations. The on-line learning algorithm of RFNNHRC was developed and implemented using a dsPIC 30F4011 DSP. Application of the proposed control scheme to heart rate responses of runners resulted in smaller fluctuations than those produced by using proportional integra control, and treadmill speeds and inclines were smoother. The present experiments demonstrate improved heart rate tracking performance with the proposed control scheme. The RFNNHRC scheme with adjustable parameters and an on-line learning algorithm was applied to a computer controlled treadmill system with heart rate control during treadmill exercise. Novel RFNNHRC structure and controller stability analyses were introduced. The RFNNHRC were tuned using a Lyapunov function to ensure system stability. The superior heart rate control with the proposed RFNNHRC scheme was demonstrated with various pre-set heart rates. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. Serum testosterone and heart rate response to short-term intense ...

    African Journals Online (AJOL)

    The serum testosterone and heart rate responses to short strenuous physical exercise were studied in twenty-one non-athletic male students. The body mass index was also determined. Serum testosterone rose significantly (p<0.05) from 0.8±0.2 ng/ml to 1.7±0.2 ng/ml (273.5±100.2%, p<0.05). Likewise, the heart rate rose ...

  6. Time domain parameters of heart rate variability in children born as small-for-gestational age.

    Science.gov (United States)

    Zamecznik, Agata; Stańczyk, Jerzy; Wosiak, Agnieszka; Niewiadomska-Jarosik, Katarzyna

    2017-05-01

    According to metabolic programming theory, small-for-gestational age patients are at high risk of cardiovascular diseases also because of the possible malfunction of the autonomic nervous system. Autonomic disorders can be assessed by heart rate variability. The aims of this study were to compare time domain parameters of heart rate variability in children born as small-for-gestational age and appropriate-for-gestational age and to assess the correlation of the postnatal and current somatic parameters with the time domain parameters. The small-for-gestational age group consisted of 68 children aged 5-10 years who were born with birth weight below the 10th percentile. The appropriate-for-gestational age group consisted of 30 healthy peers, matched in terms of gender and age. On the basis of Holter monitoring, slightly higher average heart rate was observed in the small-for-gestational age group than in the appropriate-for-gestational age group. It was found that all the time domain parameters (SDNN, SDNNi, SDANNi, rMSSD, pNN50) were lower in the small-for-gestational age group than in the appropriate-for-gestational age group. In the small-for-gestational age group, girls had lower heart rate and some of the heart rate variability parameters (SDNN, SDNNi, SDANNi) in comparison with boys. Children born as small-for-gestational age have impaired function of the autonomic nervous system. Moreover, in the small-for-gestational age group, autonomic balance moved towards the sympathetic component, which was evidenced by higher heart rate. Children with faster heart rate and lower heart rate variability parameters may be at risk of cardiovascular disease.

  7. Heart rate recovery after submaximal exercise in four different recovery protocols in male athletes and non-athletes.

    Science.gov (United States)

    Barak, Otto F; Ovcin, Zoran B; Jakovljevic, Djordje G; Lozanov-Crvenkovic, Zagorka; Brodie, David A; Grujic, Nikola G

    2011-01-01

    The effects of different recovery protocols on heart rate recovery (HRR) trend through fitted heart rate (HR) decay curves were assessed. Twenty one trained male athletes and 19 sedentary male students performed a submaximal cycle exercise test on four occasions followed by 5 min: 1) inactive recovery in the upright seated position, 2) active (cycling) recovery in the upright seated position, 3) supine position, and 4) supine position with elevated legs. The HRR was assessed as the difference between the peak exercise HR and the HR recorded following 60 seconds of recovery (HRR60). Additionally the time constant decay was obtained by fitting the 5 minute post-exercise HRR into a first-order exponential curve. Within- subject differences of HRR60 for all recovery protocols in both groups were significant (p 0.05). Values of HRR60 were larger in the group of athletes for all conditions (p recovery conditions in both groups (p 0.05). Between group difference was found for active recovery in the seated position and the supine position with elevated legs (p Active recovery in the seated upright position was associated with slower HRR compared with inactive recovery in the same position. The HRR in athletes was accelerated in the supine position with elevated legs and with active recovery in the seated position compared with non-athletes. Key pointsIn order to return to a pre-exercise value following exercise, heart rate (HR) is mediated by changes in the autonomic nervous system but the underlying mechanisms governing these changes are not well understood.Even though HRR is slower with active recovery, lactate elimination after high intensity exercise might be more important for athletes than the de-cline of heart rate.Lying supine during recovery after exercise may be an effective means of transiently restoring HR and vagal modulation and a safe position for prevention of syncope.

  8. Heart rate, multiple body temperature, long-range and long-life telemetry system for free-ranging animals

    Science.gov (United States)

    Lund, G. F.; Westbrook, R. M.; Fryer, T. B.

    1980-01-01

    The design details and rationale for a versatile, long-range, long-life telemetry data acquisition system for heart rates and body temperatures at multiple locations from free-ranging animals are presented. The design comprises an implantable transmitter for short to medium range transmission, a receiver retransmitter collar to be worn for long-range transmission, and a signal conditioner interface circuit to assist in signal discrimination and demodulation of receiver or tape-recorded audio outputs. Implanted electrodes are used to obtain an ECG, from which R-wave characteristics are selected to trigger a short RF pulse. Pulses carrying heart rate information are interrupted periodically by a series of pulse interval modulated RF pulses conveying temperature information sensed at desired locations by thermistors. Pulse duration and pulse sequencing are used to discriminate between heart rate and temperature pulses as well as radio frequency interference. The implanted transmitter may be used alone for medium and short-range tracking, or with a receiver-transmitter collar that employs commercial tracking equipment for transmissions of up to 12 km. A system prototype has been tested on a dog.

  9. Cardiac resynchronization therapy modulation of exercise left ventricular function and pulmonary O₂ uptake in heart failure.

    Science.gov (United States)

    Tomczak, Corey R; Paterson, Ian; Haykowsky, Mark J; Lawrance, Richard; Martellotto, Andres; Pantano, Alfredo; Gulamhusein, Sajad; Haennel, Robert G

    2012-06-15

    To better understand the mechanisms contributing to improved exercise capacity with cardiac resynchronization therapy (CRT), we studied the effects of 6 mo of CRT on pulmonary O(2) uptake (Vo(2)) kinetics, exercise left ventricular (LV) function, and peak Vo(2) in 12 subjects (age: 56 ± 15 yr, peak Vo(2): 12.9 ± 3.2 ml·kg(-1)·min(-1), ejection fraction: 18 ± 3%) with heart failure. We hypothesized that CRT would speed Vo(2) kinetics due to an increase in stroke volume secondary to a reduction in LV end-systolic volume (ESV) and that the increase in peak Vo(2) would be related to an increase in cardiac output reserve. We found that Vo(2) kinetics were faster during the transition to moderate-intensity exercise after CRT (pre-CRT: 69 ± 21 s vs. post-CRT: 54 ± 17 s, P 0.05). CRT improved heart rate, measured as a lower resting and steady-state exercise heart rate and as faster heart rate kinetics after CRT (pre-CRT: 89 ± 12 s vs. post-CRT: 69 ± 21 s, P cardiac output reserve increased significantly post-CRT and was 22% higher at peak exercise post-CRT (both P cardiac output was due to both a significant increase in peak and reserve stroke volume and to a nonsignificant increase in heart rate reserve. Similar patterns in LV volumes as moderate-intensity exercise were observed at peak exercise. Cardiac output reserve was related to peak Vo(2) (r = 0.48, P chronic CRT-mediated cardiac factors that contribute, in part, to the speeding in Vo(2) kinetics and increase in peak Vo(2) in clinically stable heart failure patients.

  10. Aerobic exercise during pregnancy and presence of fetal-maternal heart rate synchronization.

    Directory of Open Access Journals (Sweden)

    Peter Van Leeuwen

    Full Text Available It has been shown that short-term direct interaction between maternal and fetal heart rates may take place and that this interaction is affected by the rate of maternal respiration. The aim of this study was to determine the effect of maternal aerobic exercise during pregnancy on the occurrence of fetal-maternal heart rate synchronization.In 40 pregnant women at the 36th week of gestation, 21 of whom exercised regularly, we acquired 18 min. RR interval time series obtained simultaneously in the mothers and their fetuses from magnetocardiographic recordings. The time series of the two groups were examined with respect to their heart rate variability, the maternal respiratory rate and the presence of synchronization epochs as determined on the basis of synchrograms. Surrogate data were used to assess whether the occurrence of synchronization was due to chance.In the original data, we found synchronization occurred less often in pregnancies in which the mothers had exercised regularly. These subjects also displayed higher combined fetal-maternal heart rate variability and lower maternal respiratory rates. Analysis of the surrogate data showed shorter epochs of synchronization and a lack of the phase coordination found between maternal and fetal beat timing in the original data.The results suggest that fetal-maternal heart rate coupling is present but generally weak. Maternal exercise has a damping effect on its occurrence, most likely due to an increase in beat-to-beat differences, higher vagal tone and slower breathing rates.

  11. The effect of Noise on blood pressure and heart rate in an automotive industry

    Directory of Open Access Journals (Sweden)

    Iraj Alimohammadi

    2017-06-01

    Full Text Available Introduction: One of the possible effects of occupational exposure to high noise is high blood pressure and cardiovascular disease. Aim of this study was to investigate the association between noise with blood pressure and heart rate in an automotive industry. Methods: 78 male workers who worked in an automobile factory, were participated. Blood pressure and heart rate were measured in the morning and in the middle of the day. All measurements were performed at three noise levels: 85-95, 75-85 and 65-75 dB. All data were analyzed using SPSS and MATLAB. Results: Post Hoc test showed that noise has the same effect on the average systolic and diastolic blood pressure (p= 0.733 but Box-whisker plot showed that after exposure, the variation range of blood pressure and heart rate are much more than the other groups. However, this project didn’t show any a specific correlation between the increase in noise level with heart rate but variance analysis showed that the noise level increase lead to changes in heart rate (p= 0.049.  Conclusions: Noise level in 75-85dB as same as 85-95 dB caused the changes in blood pressure and heart rate. Due to cardiovascular disease, it is recommended training programs for workers, reduced noise level and periodic monitoring of blood pressure of workers, especially with a history of hypertension.

  12. Activity and heart rate in semi-domesticated reindeer during adaptation to emergency feeding.

    Science.gov (United States)

    Nilsson, A; Ahman, B; Norberg, H; Redbo, I; Eloranta, E; Olsson, K

    2006-06-15

    Although reindeer are well adapted to limited food resources during winter, semi-domesticated reindeer are regularly fed when snow conditions are bad in order to prevent starvation. Feeding sometimes results in health problems and loss of animals. This study was made to assess if activity pattern in reindeer could be used as a tool for the reindeer herder in early detection of animals that are not adapting to feeding. The frequency of 10 behavioural categories was recorded in five groups of penned, eight-month-old, female semi-domesticated reindeer. Three reindeer per group were fitted with heart rate monitors. Lying was the most frequent behaviour, whilst there were few cases of agonistic behaviour. Heart rate varied during the day, with peaks during feeding and low heart rates in the early morning. Restricted feed intake resulted in more locomotion and seeking but less ruminating compared to feeding ad libitum. This was followed by a generally lower heart rate in reindeer in the restricted groups compared to controls. Subsequent feeding with different combinations of lichens, silage and pellets ad libitum resulted initially in significantly more of the animals lying curled up, compared to controls, combined with increased heart rates. As the experiment continued the general activity pattern, as well as the heart rate, gradually became more similar in all groups. Lying curled was the behavioural indicator most consistently affected by feed deprivation and adaptation to feeding and may thus be a useful indicator to distinguish individual reindeer that are not adjusting to feeding.

  13. Heart Rate Response in Spectators of the Montreal Canadiens Hockey Team.

    Science.gov (United States)

    Khairy, Leia T; Barin, Roxana; Demonière, Fabrice; Villemaire, Christine; Billo, Marie-Josée; Tardif, Jean-Claude; Macle, Laurent; Khairy, Paul

    2017-12-01

    To our knowledge, heart rate responses have not previously been assessed in hockey fans. We quantified heart rate increases in spectators of the Montreal Canadiens, compared televised with live games, explored features associated with peak heart rates, and assessed whether increases correlate with a fan passion score. Healthy adults were enrolled, with half attending live games and half viewing televised games. All subjects completed questionnaires and had continuous Holter monitoring. Intensity of the physical stress response was defined according to previously published heart rate index thresholds as mild ( 1.83). In 20 participants, 35% women, age 46 ± 10 years, the heart rate increased by a median of 92% during the hockey game, from 60 (interquartile range, 54-65) beats per minute at rest to 114 (interquartile range, 103-129) beats per minute (P hockey game is associated with a heart rate response equivalent to vigorous physical stress and a televised game to moderate physical stress. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  14. The effect of competition on heart rate during kart driving: A field study

    Science.gov (United States)

    2011-01-01

    Background Both the act of competing, which can create a kind of mental stress, and participation in motor sports, which induces physical stress from intense g-forces, are known to increase heart rate dramatically. However, little is known about the specific effect of competition on heart rate during motor sports, particularly during four-wheel car driving. The goal of this preliminary study, therefore, was to investigate whether competition increases heart rate under such situations. Findings The participants drove an entry-level formula kart during two competitive races and during solo driving against the clock while heart rate and g-forces were measured. Analyses showed that heart rate values during the races (168.8 beats/min) were significantly higher than those during solo driving (140.9 beats/min) and rest (75.1 beats/min). Conclusions The results of this preliminary study indicate that competition heightens heart rate during four-wheel car driving. Kart drivers should be concerned about maintaining good health and developing physical strength. PMID:21906298

  15. Estimation of heart rate variability using a compact radiofrequency motion sensor.

    Science.gov (United States)

    Sugita, Norihiro; Matsuoka, Narumi; Yoshizawa, Makoto; Abe, Makoto; Homma, Noriyasu; Otake, Hideharu; Kim, Junghyun; Ohtaki, Yukio

    2015-12-01

    Physiological indices that reflect autonomic nervous activity are considered useful for monitoring peoples' health on a daily basis. A number of such indices are derived from heart rate variability, which is obtained by a radiofrequency (RF) motion sensor without making physical contact with the user's body. However, the bulkiness of RF motion sensors used in previous studies makes them unsuitable for home use. In this study, a new method to measure heart rate variability using a compact RF motion sensor that is sufficiently small to fit in a user's shirt pocket is proposed. To extract a heart rate related component from the sensor signal, an algorithm that optimizes a digital filter based on the power spectral density of the signal is proposed. The signals of the RF motion sensor were measured for 29 subjects during the resting state and their heart rate variability was estimated from the measured signals using the proposed method and a conventional method. A correlation coefficient between true heart rate and heart rate estimated from the proposed method was 0.69. Further, the experimental results showed the viability of the RF sensor for monitoring autonomic nervous activity. However, some improvements such as controlling the direction of sensing were necessary for stable measurement. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  16. Effect of Temperature on Heart Rate Variability in Neonatal ICU Patients With Hypoxic-Ischemic Encephalopathy.

    Science.gov (United States)

    Massaro, An N; Campbell, Heather E; Metzler, Marina; Al-Shargabi, Tareq; Wang, Yunfei; du Plessis, Adre; Govindan, Rathinaswamy B

    2017-04-01

    To determine whether measures of heart rate variability are related to changes in temperature during rewarming after therapeutic hypothermia for hypoxic-ischemic encephalopathy. Prospective observational study. Level 4 neonatal ICU in a free-standing academic children's hospital. Forty-four infants with moderate to severe hypoxic-ischemic encephalopathy treated with therapeutic hypothermia. Continuous electrocardiogram data from 2 hours prior to rewarming through 2 hours after completion of rewarming (up to 10 hr) were analyzed. Median beat-to-beat interval and measures of heart rate variability were quantified including beat-to-beat interval SD, low and high frequency relative spectral power, detrended fluctuation analysis short and long α exponents (αS and αL), and root mean square short and long time scales. The relationships between heart rate variability measures and esophageal/axillary temperatures were evaluated. Heart rate variability measures low frequency, αS, and root mean square short and long time scales were negatively associated, whereas αL was positively associated, with temperature (p variability as temperature increased toward normothermia. Measures of heart rate variability are temperature dependent in the range of therapeutic hypothermia to normothermia. Core body temperature needs to be considered when evaluating heart rate variability metrics as potential physiologic biomarkers of illness severity in hypoxic-ischemic encephalopathy infants undergoing therapeutic hypothermia.

  17. The effect of orthostatic stress on multiscale entropy of heart rate and blood pressure

    International Nuclear Information System (INIS)

    Turianikova, Zuzana; Javorka, Kamil; Calkovska, Andrea; Javorka, Michal; Baumert, Mathias

    2011-01-01

    Cardiovascular control acts over multiple time scales, which introduces a significant amount of complexity to heart rate and blood pressure time series. Multiscale entropy (MSE) analysis has been developed to quantify the complexity of a time series over multiple time scales. In previous studies, MSE analyses identified impaired cardiovascular control and increased cardiovascular risk in various pathological conditions. Despite the increasing acceptance of the MSE technique in clinical research, information underpinning the involvement of the autonomic nervous system in the MSE of heart rate and blood pressure is lacking. The objective of this study is to investigate the effect of orthostatic challenge on the MSE of heart rate and blood pressure variability (HRV, BPV) and the correlation between MSE (complexity measures) and traditional linear (time and frequency domain) measures. MSE analysis of HRV and BPV was performed in 28 healthy young subjects on 1000 consecutive heart beats in the supine and standing positions. Sample entropy values were assessed on scales of 1–10. We found that MSE of heart rate and blood pressure signals is sensitive to changes in autonomic balance caused by postural change from the supine to the standing position. The effect of orthostatic challenge on heart rate and blood pressure complexity depended on the time scale under investigation. Entropy values did not correlate with the mean values of heart rate and blood pressure and showed only weak correlations with linear HRV and BPV measures. In conclusion, the MSE analysis of heart rate and blood pressure provides a sensitive tool to detect changes in autonomic balance as induced by postural change

  18. [Body composition and heart rate variability in patients with chronic obstructive pulmonary disease pulmonary rehabilitation candidates].

    Science.gov (United States)

    Curilem Gatica, Cristian; Almagià Flores, Atilio; Yuing Farías, Tuillang; Rodríguez Rodríguez, Fernando

    2014-07-01

    Body composition is a non-invasive method, which gives us information about the distribution of tissues in the body structure, it is also an indicator of the risk of mortality in patients with chronic obstructive pulmonary disease. The heart rate variability is a technique that gives us information of autonomic physiological condition, being recognized as an indicator which is decreased in a number of diseases. The purpose of this study was to assess body composition and heart rate variability. The methodology used is that of Debora Kerr (1988) endorsed by the International Society for advances in Cineantropometría for body composition and heart rate variability of the guidelines described by the American Heart Association (1996). Roscraff equipment, caliper Slimguide and watch Polar RS 800CX was used. , BMI 26.7 ± 3.9 kg / m²; Muscle Mass 26.1 ± 6.3 kg ; Bone Mass 1.3 kg ± 8.1 76 ± 9.9 years Age : 14 candidates for pulmonary rehabilitation patients were evaluated , Adipose mass 16.4 ± 3.6 kg ; FEV1 54 ± 14%. Increased waist circumference and waist hip ratio was associated with a lower overall heart rate variability. The bone component was positively related to the variability of heart rate and patients with higher forced expiratory volume in one second had lower high frequency component in heart rate variability. In these patients, the heart rate variability is reduced globally and is associated with cardiovascular risk parameters. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  19. Changes in total death rate and in ischaemic heart disease death ...

    African Journals Online (AJOL)

    Changes in total death rate and in ischaemic heart disease death rate in interethnic South African populations, 1978 - 1989. ... While knowledge of the reasons for the rises and falls in IHD rates reInains incomplete, whites have none the less taken some preventive action, although Asians and coloureds apparently little.

  20. Heart Rate and Oxygen Uptake Recovery and the Level of Aerobic Capacity in Mountain Bikers

    Directory of Open Access Journals (Sweden)

    Michalik Kamil

    2017-12-01

    Full Text Available Introduction. Since mountain biking involves exercise of varying intensity, competitive performance may be affected by the rate of recovery. The aim of the current study was to determine whether maximal oxygen uptake is associated with the rate of heart rate and oxygen uptake recovery in mountain bike athletes.

  1. Effects of hot-iron branding on heart rate, breathing rate and behaviour of anaesthetised Steller sea lions.

    Science.gov (United States)

    Walker, K A; Mellish, J E; Weary, D M

    2011-10-01

    This study assessed the heart rate, breathing rate and behavioural responses of 12 juvenile Steller sea lions during hot-iron branding under isoflurane anaesthesia. Physiological and behavioural measures were recorded in four periods: baseline (five minutes), sham branding (one minute), branding (approximately 2.7 minutes) and postbranding (five minutes). No difference in heart rate was noted from baseline to sham branding, but heart rate increased from mean (sem) 78.3 (2.4) bpm in the baseline period to 85.6 (2.5) bpm in the branding period. Heart rate remained elevated in the postbranding period, averaging 84.7 (2.5) bpm. Breathing rate averaged 2.5 (1.0) breaths/minute in the baseline and sham branding periods increased to 8.9 (1.0) breaths/minute during branding, but returned to baseline by the postbranding period. Behaviourally, half of the sea lions exhibited trembling and head and shoulder movements during branding.

  2. Reliability of the Parabola Approximation Method in Heart Rate Variability Analysis Using Low-Sampling-Rate Photoplethysmography.

    Science.gov (United States)

    Baek, Hyun Jae; Shin, JaeWook; Jin, Gunwoo; Cho, Jaegeol

    2017-10-24

    Photoplethysmographic signals are useful for heart rate variability analysis in practical ambulatory applications. While reducing the sampling rate of signals is an important consideration for modern wearable devices that enable 24/7 continuous monitoring, there have not been many studies that have investigated how to compensate the low timing resolution of low-sampling-rate signals for accurate heart rate variability analysis. In this study, we utilized the parabola approximation method and measured it against the conventional cubic spline interpolation method for the time, frequency, and nonlinear domain variables of heart rate variability. For each parameter, the intra-class correlation, standard error of measurement, Bland-Altman 95% limits of agreement and root mean squared relative error were presented. Also, elapsed time taken to compute each interpolation algorithm was investigated. The results indicated that parabola approximation is a simple, fast, and accurate algorithm-based method for compensating the low timing resolution of pulse beat intervals. In addition, the method showed comparable performance with the conventional cubic spline interpolation method. Even though the absolute value of the heart rate variability variables calculated using a signal sampled at 20 Hz were not exactly matched with those calculated using a reference signal sampled at 250 Hz, the parabola approximation method remains a good interpolation method for assessing trends in HRV measurements for low-power wearable applications.

  3. Design and evaluation of a handheld impedance plethysmograph for measuring heart rate variability

    DEFF Research Database (Denmark)

    Kristiansen, N. K.; Fleischer, J.; Jensen, M. S.

    2005-01-01

    Heart rate variability (HRV) analysis from 10s ECGs has been shown to be reliable. However, the short examination time warrants a user-friendly system that can be used for ad-hoc examinations without normal preparation, unlike ECG. A handheld device has been developed that can measure ultra...... as the reference method. Agreement between the two methods in measuring heart rate and root mean square of successive differences in the heart beat interval (RMSSD) was analysed using correlation coefficients (Pearson's R-2), mean differences with 95% confidence intervals and 95% limits of agreement, and Bland......-Altman plots. The correlation between the two methods was R-2 = 1.00 and R-2 = 0.99 when heart rate and RMSSD were measured, respectively. The Bland-Altman plots showed suitable agreement between the novel device and standard 10 s ECGs, which was substantiated by 95% limits of agreement of the difference...

  4. Power optimisation for wearable heart rate measurement device with wireless charging.

    Science.gov (United States)

    Kiruthiga, G; Sharmila, A; Mahalakshmi, P; Muruganandam, M

    2017-05-01

    Continuous measurement of heart rate is necessary for monitoring the patients with heart ailments. A wearable which continuously measures heart rate of an individual by a method called reflectance-based photoplethysmography (PPG) computes the heart rate of an individual according to the volumetric changes in blood flowing through the body is developed. In order to make the device more compact as well as with IP67 and IP68 standard, wireless charging technique is employed because it helps to get rid of wires while charging. Following the Qi standard for designing wireless power receiver circuits makes the device interoperable and work with greater efficiency with reduced losses. Impedance matching and designing the circuit to operate under resonance condition increases coupling efficiency in case of inductive coupling.

  5. Comparison of cardiac time intervals between echocardiography and impedance cardiography at various heart rates

    Directory of Open Access Journals (Sweden)

    Maureen A.J.M. van Eijnatten

    2014-04-01

    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.

  6. C-reactive protein, heart rate variability and prognosis in community subjects with no apparent heart disease

    DEFF Research Database (Denmark)

    Sajadieh, A; Nielsen, OW; Rasmussen, Verner

    2006-01-01

    OBJECTIVES: Increased C-reactive protein (CRP) and reduced heart rate variability (HRV) both indicate poor prognosis. An inverse association between HRV and CRP has been reported, suggesting an interaction between inflammatory and autonomic systems. However, the prognostic impact...... of this interaction has not been studied. We thus investigated the prognostic impact of CRP, HRV and their combinations. DESIGN: Population-based study. SUBJECTS: A total of 638 middle-aged and elderly subjects with no apparent heart disease from community. METHODS: All were studied by clinical and laboratory...... of four HRV measures were significantly associated with increased rate of death or myocardial infarction. In a Cox model with CRP >or=2.5 microg mL(-1), standard deviation for the mean value of the time between normal complexes...

  7. Heart-rate reduction by If-channel inhibition with ivabradine restores collateral artery growth in hypercholesterolemic atherosclerosis.

    Science.gov (United States)

    Schirmer, Stephan H; Degen, Achim; Baumhäkel, Magnus; Custodis, Florian; Schuh, Lisa; Kohlhaas, Michael; Friedrich, Erik; Bahlmann, Ferdinand; Kappl, Reinhard; Maack, Christoph; Böhm, Michael; Laufs, Ulrich

    2012-05-01

    Collateral arteries protect tissue from ischaemia. Heart rate correlates with vascular events in patients with arterial obstructive disease. Here, we tested the effect of heart-rate reduction (HRR) on collateral artery growth. The I(f)-channel inhibitor ivabradine reduced heart rate by 11% in wild-type and 15% in apolipoprotein E (ApoE)(-/-) mice and restored endothelium-dependent relaxation in aortic rings of ApoE(-/-) mice. Microsphere perfusion and angiographies demonstrated that ivabradine did not change hindlimb perfusion in wild-type mice but improved perfusion in ApoE(-/-) mice from 40.5 ± 15.8-60.2 ± 18.5% ligated/unligated hindlimb. Heart rate reduction (13%) with metoprolol failed to improve endothelial function and perfusion. Protein expression of endothelial nitric oxide synthase (eNOS), phosphorylated eNOS, and eNOS activity were increased in collateral tissue following ivabradine treatment of ApoE(-/-) mice. Co-treatment with nitric oxide-inhibitor N (G)-nitro-L-arginine methyl ester abolished the effects of ivabradine on arteriogenesis. Following ivabradine, classical inflammatory cytokine expression was lowered in ApoE(-/-) circulating mononuclear cells and in plasma, but unaltered in collateral-containing hindlimb tissue, where numbers of perivascular macrophages also remained unchanged. However, ivabradine reduced expression of anti-arteriogenic cytokines CXCL10and CXCL11 and of smooth muscle cell markers smoothelin and desmin in ApoE(-/-) hindlimb tissue. Endothelial nitric oxide synthase and inflammatory cytokine expression were unchanged in wild-type mice. Ivabradine did not affect cytokine production in HUVECs and THP1 mononuclear cells and had no effect on the membrane potential of HUVECs in patch-clamp experiments. Ivabradine-induced HRR stimulates adaptive collateral artery growth. Important contributing mechanisms include improved endothelial function, eNOS activity, and modulation of inflammatory cytokine gene expression.

  8. Contrast material injection protocol with the flow rate adjusted to the heart rate for dual source CT coronary angiography.

    Science.gov (United States)

    Zhu, Xiaomei; Chen, Wenping; Li, Mei; Xu, Yi; Xu, Hai; Zhu, Yinsu; Wang, Dehang; Tang, Lijun

    2012-08-01

    To investigate the effect on coronary arterial attenuations of contrast material flow rate adjusted to a patient's heart rate during dual source CT coronary angiography (DSCT-CCTA). A total of 296 consecutive patients (mean age: 58.7 years) undergoing DSCT-CCTA without previous coronary stent placement, bypass surgery, congenital or valvular heart disease were included. The image acquisition protocol was standardized (120 kV, 380 mAs) and retrospective electrocardiograph (ECG) gating was used. Patients were randomly assigned to one of three groups [flow rate: G1: dosage/16, G2: dosage/(scan time +8), G3: fixed flow rate]. The groups were compared with respect to the attenuations of the ascending aorta (AA) above coronary ostia, the left main coronary artery (LM), the proximal right coronary artery (RCA), the left anterior descending artery (LAD), the left circumflex artery (LCX), and the contrast to noise ratio of the LM (LM(CNR)) and the proximal RCA (RCA(CNR)). Correlations between heart rate and attenuation of the coronary arteries were evaluated in three groups with linear regression. There was no significant difference in the three groups among the mean attenuations of AA (P = 0.141), LM (P = 0.068), RCA (P = 0.284), LM(CNR) (P = 0.598) and RCA(CNR) (P = 0.546). The attenuations of the LAD and the LCX in group 1 were slightly higher than those in group 2 and 3 (P material flow rate adjusted to heart rate can diminish the influence of heart rate on attenuations of the coronary arteries in DSCT-CCTA.

  9. Effects of Chronic Pelvic Pain on Heart Rate Variability in Women.

    Science.gov (United States)

    Williams, DeWayne P; Chelimsky, Gisela; McCabe, N Patrick; Koenig, Julian; Singh, Partik; Janata, Jeffrey; Thayer, Julian F; Buffington, C A Tony; Chelimsky, Thomas

    2015-11-01

    Interstitial cystitis/bladder pain syndrome and myofascial pelvic pain are frequently comorbid chronic pelvic pain disorders. Differences in bladder function between interstitial cystitis/bladder pain syndrome and myofascial pelvic pain suggest that efferent autonomic function may differentiate these syndromes. Heart rate variability, defined as the difference in duration of successive heartbeats, serves as an index of autonomic function by measuring its ability to modify heart rate in response to neurophysiological changes. High frequency heart rate variability was used as a reflection of more rapid vagally mediated (parasympathetic) changes. Low frequency heart rate variability signified slower fluctuations related to the baroreflex and sympathetic outflow. Heart rate va