Regulation Of Heart Rate Variability Research Articles

Derangement of autonomic nerve control in rat with right ventricular failure

The effects of right ventricular hypertrophy and eventual right ventricular failure on autonomic nerve regulation of heart rate variability were investigated using rats with monocrotaline (MCT)-induced pulmonary hypertension. ECG signals were obtained from a radio transmitter placed into the subcutaneous pouch in the back of the male MCT-treated and control rats for 30 min every 6 h at a sample rate of 5 kHz with or without injection of atropine (2 mg/kg I.P.) or propranolol (4 mg/kg I.P.), in a room equipped with a climate controller. Heart rate (HR) and HR variability (HRV) were analyzed in each group by power spectrograms obtained by the fast-Fourier transform algorithm. The RR interval, total power (TP), low-frequency (LF) power (0.04–0.73 Hz), high-frequency (HF) power (0.73–2 Hz) and LF/HF ( L/ H) ratio were measured. HR was significantly increased in the MCT-treated rats ( P<0.001), which also presented lower HRV than that of the control Wistar rats; TP ( P<0.05) and HF ( P<0.05) power, but not the L/ H ratio, were significantly lower than that of the control rats. Responses of these parameters to a muscarinic antagonist (atropine: 2 mg/kg) and a β-adrenergic antagonist (propranolol: 4 mg/kg), however, remained intact in the MCT-treated rats. Only the parasympathetic component of autonomic nervous controls of HRV was deranged in rats with MCT-induced right ventricular failure.

Relationship of aggression and anxiety to autonomic regulation of heart rate variability in adolescent males.

Annals of the New York Academy of SciencesVolume 794, Issue 1 p. 376-379 Relationship of Aggression and Anxiety to Autonomic Regulation of Heart Rate Variability in Adolescent Males ENRICO MEZZACAPPA, Corresponding Author ENRICO MEZZACAPPA Judge Baker Children's Center Harvard University Boston, MassachusettsAddress for correspondence: The Judge Baker Children's Center, 295 Longwood Avenue, Boston, MA 02115. Tel: (617) 232-8390, ext. 2603. Fax: (617) 232-8399; e-mail: [email protected]Search for more papers by this authorRICHARD E. TREMBLAY, RICHARD E. TREMBLAY Research Unit on Children's Psychosocial Maladjustment University of Montreal Montreal, CanadaSearch for more papers by this authorDANIEL KINDLON, DANIEL KINDLON Division of Maternal and Child Health Harvard School of Public Health Harvard University Boston, MassachusettsSearch for more papers by this authorJ. PHILIP SAUL, J. PHILIP SAUL Division of Cardiology The Children's Hospital Harvard University Boston, MassachusettsSearch for more papers by this authorLOUISE ARSENEAULT, LOUISE ARSENEAULT Research Unit on Children's Psychosocial Maladjustment University of Montreal Montreal, CanadaSearch for more papers by this authorROBERT O. PIHL AND, ROBERT O. PIHL AND Research Unit on Children's Psychosocial Maladjustment University of Montreal Montreal, Canada Department of Psychology McGill University Montreal, CanadaSearch for more papers by this authorFELTON EARLS, FELTON EARLS Division of Maternal and Child Health Harvard School of Public Health Harvard University Boston, MassachusettsSearch for more papers by this author ENRICO MEZZACAPPA, Corresponding Author ENRICO MEZZACAPPA Judge Baker Children's Center Harvard University Boston, MassachusettsAddress for correspondence: The Judge Baker Children's Center, 295 Longwood Avenue, Boston, MA 02115. Tel: (617) 232-8390, ext. 2603. Fax: (617) 232-8399; e-mail: [email protected]Search for more papers by this authorRICHARD E. TREMBLAY, RICHARD E. TREMBLAY Research Unit on Children's Psychosocial Maladjustment University of Montreal Montreal, CanadaSearch for more papers by this authorDANIEL KINDLON, DANIEL KINDLON Division of Maternal and Child Health Harvard School of Public Health Harvard University Boston, MassachusettsSearch for more papers by this authorJ. PHILIP SAUL, J. PHILIP SAUL Division of Cardiology The Children's Hospital Harvard University Boston, MassachusettsSearch for more papers by this authorLOUISE ARSENEAULT, LOUISE ARSENEAULT Research Unit on Children's Psychosocial Maladjustment University of Montreal Montreal, CanadaSearch for more papers by this authorROBERT O. PIHL AND, ROBERT O. PIHL AND Research Unit on Children's Psychosocial Maladjustment University of Montreal Montreal, Canada Department of Psychology McGill University Montreal, CanadaSearch for more papers by this authorFELTON EARLS, FELTON EARLS Division of Maternal and Child Health Harvard School of Public Health Harvard University Boston, MassachusettsSearch for more papers by this author First published: September 1996 https://doi.org/10.1111/j.1749-6632.1996.tb32547.xCitations: 17AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume794, Issue1Understanding Aggressive Behavior in ChildrenSeptember 1996Pages 376-379 RelatedInformation

Chaos-related deterministic regulation of heart rate variability in time- and frequency domains: effects of autonomic blockade and exercise

Chaos-related deterministic regulation of heart rate variability in time- and frequency domains: effects of autonomic blockade and exercise

Chaos-related deterministic regulation of heart rate variability in time- and frequency domains: effects of autonomic blockade and exercise

To study non-linear complexity or chaotic behaviour of heart rate in short time series and its dependence on autonomic tone. Ten healthy individuals (5 men, mean age 44 years) were investigated at rest, after intravenous injections of propranolol (0.15 mg/kg), followed by atropine (0.03 mg/kg). On another occasion, investigation was made during exercise on a bicycle ergometer at 40% and at 70% of maximal working capacity. Heart rate variability was assessed by: local sensitive dependence on initial conditions as quantitated by the dominant Lyapunov exponent, coefficient of variation of heart rate, power spectral analysis of high- and low-frequency bands and the 1/f-slope of the very-low-frequency band and time domain analysis. The approximate dominant Lyapunov exponent was positive at rest and remained positive during autonomic blockade and during exercise. The exponent decreased significantly with propranolol+atropine and even more so during exercise but did not attain zero. At baseline approximate predictability was lost after about 30 s whereas after autonomic blockade or exercise it was lost after about 60 s. The 1/f-slope remained unaltered around -1. As expected, power in high- and low-frequency bands as well as time domain index decreased significantly with autonomic blockade. The low-frequency band and time domain index were affected by exercise. Heart rate variability of sinus rhythm in healthy individuals has characteristics suggestive of low-dimensional chaos-like determinism which is modulated but not eliminated by inhibition of autonomic tone or by exercise. The dominant Lyapunov exponent characterises heart rate variability independent or the other investigated measures.

Neural regulation of heart rate variability in endurance athletes and sedentary controls

The aim was to examine the cardiac autonomic responses to orthostatic stress and recovery from steady state exercise in endurance trained athletes and sedentary subjects. The power spectrum of heart rate variability was measured before and after exercise in 10 male long distance runners and 14 male sedentary control subjects. Both groups were comparable in sex, age, and body mass index. Continuous ECG recordings were obtained during the following physiological manoeuvres: 45 min supine rest state; 10 min standing; 15 min steady state exercise at 50% maximum workload, and 15 min while supine during post-exercise recovery. The resting heart rate of athletes was lower than controls, at 52(SD 4.9) v 67(8.7) beats.min-1, p < 0.001. Power spectrum analysis was performed using autoregressive modelling. The resting high frequency (HF) vagal component was higher in athletes than controls, at 62 (10.7) v 44(22.4) beats.min-1.Hz-1, p < 0.05. The resting low frequency (LF) peak power was significantly reduced in athletes, at 54(9.9) v 70(19.5) in control, p < 0.05. Although no group differences were observed during upright posture or exercise, the LF:HF area ratio had already returned to pre-exercise levels within 5 min of recovery in athletes. Conversely, it required up to 15 min of recovery before a noticeable decrease in the LF:HF area ratio was seen in controls. These data support the hypothesis that endurance training modifies heart rate control in whole or in part through neurocardiac mechanisms.

Assessment of autonomic regulation of heart rate variability by the method of complex demodulation.

Complex demodulation was used to examine the effect of both divisions of the autonomic nervous system (sympathetic and parasympathetic) on heart rate. Data were analyzed from dogs during classical conditioning procedures which caused different changes in the autonomic regulation of heart rate. Two significant peaks in the heart rate variability spectrum were examined by this technique. The amplitude of the peak at the respiration frequency showed parasympathetic changes, while the amplitude of the low frequency peak (0-0.124 Hz) showed both sympathetic and parasympathetic effects. Complex demodulation results at these frequencies clearly showed the activities of both branches of the autonomic nervous system in regulating heart rate. During the CS+ period, when trained dogs were presented with a tone predicting a subsequent shock, the observed tachycardia was due to decreased parasympathetic activity and a transient increase in sympathetic activity. During the CS- period where a different tone predicts no shock, parasympathetic and sympathetic activities were unchanged from the baseline condition. The use of complex demodulation enables us to examine autonomic contributions to heart rate regulation in conditioning and a variety of other physiological and environmental conditions where autonomic input can be expected to change rapidly.