Symbolic Dynamics of Heart Rate Variability
- 26 July 2005
- journal article
- research article
- Published by Ovid Technologies (Wolters Kluwer Health) in Circulation
- Vol. 112 (4), 465-470
- https://doi.org/10.1161/circulationaha.104.518449
Abstract
Background— Sympathetic and parasympathetic systems are considered the principal rapidly reacting systems that control heart rate. Methods and Results— We propose a symbolic analysis series to quantify the prevalence of sympathetic or parasympathetic cardiac modulation. This analysis decomposes the heart rate variability series in patterns lasting 3 beats and classifies them into 3 categories: nonvariable, variable, and very variable patterns referred to as 0V, 1V, and 2V patterns. First, we applied this method to experimental and pharmacological conditions characterized by sympathetic activation (tilt test, handgrip, nitroprusside, and high-dose atropine administration) or parasympathetic activation (phenylephrine and low-dose atropine administration) in 60 healthy subjects. An increase in sympathetic modulation and a vagal withdrawal elicited a significant increase in 0V patterns and a decrease in 2V patterns, whereas parasympathetic dominance induced the opposite, reflecting a reciprocal sympathovagal balance. The second part of the study considered a series of 300 beats before the onset of major arrhythmic events in patients with an implantable cardioverter-defibrillator. Symbolic analysis detected an increase in the percentage of 0V patterns before the onset of major arrhythmias compared with baseline (41.6±3.9% and 24.4±2.9%, respectively; P Conclusions— Symbolic analysis of 3 beat sequences takes into account the different time course of sympathetic and parasympathetic cardiac modulations and seems appropriate for elucidating the neural pathophysiological mechanisms occurring during the short periods that precede acute cardiac events.Keywords
This publication has 20 references indexed in Scilit:
- Prediction of Sudden Cardiac DeathCirculation, 2003
- Autonomic nervous system activity and the spontaneous initiation of ventricular tachycardiaJournal of the American College of Cardiology, 1998
- Relation between heart rate variability and spontaneous and induced ventricular arrhythmias in patients with coronary artery diseaseJournal of the American College of Cardiology, 1995
- Electrical Alternans and Vulnerability to Ventricular ArrhythmiasThe New England Journal of Medicine, 1994
- The role of the autonomic nervous system in sudden cardiac deathTrends in Cardiovascular Medicine, 1992
- Power Spectrum Analysis of Heart Rate Fluctuation: A Quantitative Probe of Beat-to-Beat Cardiovascular ControlScience, 1981
- Neural mechanisms in life-threatening arrhythmiasAmerican Heart Journal, 1980
- Reciprocal and non-reciprocal action of the vagal and sympathetic nerves innervating the heartJournal of the Autonomic Nervous System, 1979
- Electrical alternation of the T-wave: Clinical and experimental evidence of its relationship with the sympathetic nervous system and with the long Q-T syndromeAmerican Heart Journal, 1975
- Estimation of the conduction time of the baroreceptor-cardiac reflex in manCardiovascular Research, 1973