Mechanisms of ventricular arrhythmias: a dynamical systems-based perspective

Abstract

Cherry EM, Fenton FH, Gilmour RF Jr. Mechanisms of ventricular arrhythmias: a dynamical systems-based perspective. Am J Physiol Heart Circ Physiol 302: H2451-H2463, 2012. First published March 30, 2012 doi:10.1152/ajpheart.00770.2011Defining the cellular electrophysiological mechanisms for ventricular tachyarrhythmias is difficult, given the wide array of potential mechanisms, ranging from abnormal automaticity to various types of reentry and kk activity. The degree of difficulty is increased further by the fact that any particular mechanism may be influenced by the evolving ionic and anatomic environments associated with many forms of heart disease. Consequently, static measures of a single electrophysiological characteristic are unlikely to be useful in establishing mechanisms. Rather, the dynamics of the electrophysiological triggers and substrates that predispose to arrhythmia development need to be considered. Moreover, the dynamics need to be considered in the context of a system, one that displays certain predictable behaviors, but also one that may contain seemingly stochastic elements. It also is essential to recognize that even the predictable behaviors of this complex nonlinear system are subject to small changes in the state of the system at any given time. Here we briefly review some of the short-, medium-, and long-term alterations of the electrophysiological substrate that accompany myocardial disease and their potential impact on the initiation and maintenance of ventricular arrhythmias. We also provide examples of cases in which small changes in the electrophysiological substrate can result in rather large differences in arrhythmia outcome. These results suggest that an interrogation of cardiac electrical dynamics is required to provide a meaningful assessment of the immediate risk for arrhythmia development and for evaluating the effects of putative antiarrhythmic interventions.alternans; dynamics; spiral waves; ventricle THIS REVIEW ARTICLE is part of a collection on Electrophysiology and Excitation-Contraction Coupling. Other articles appearing in this collection, as well as a full archive of all Review collections, can be found online at http://ajpheart. physiology.org/.

Control of electrical turbulence by periodic excitation of cardiac tissue

“…abnormal or irregular heart rhythms) including atrial fibrillation (AF), ventricular fibrillation (VF), and ventricular tachycardia (VT). The nonlinear dynamics of electrical excitation waves in cardiac tissue has been studied extensively in experiment and simulation for more than two decades, for recent reviews see e. g. [1][2][3][4][5] . VF represents a particularly dangerous malfunction of the heart, in which synchronous excitation and contraction of different parts of the ventricles is lost, potentially causing sudden death if left untreated for more than a few minutes.…”

Na/K pump regulation of cardiac repolarization: insights from a systems biology approach

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Development of Time- and Voltage-Domain Mapping (V-T-Mapping) to Localize Ventricular Tachycardia Channels During Sinus Rhythm

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