Autonomic function and ventricular tachyarrhythmias during acute myocardial infarction

Abstract

Most cases of sudden cardiac death are attributed to sustained ventricular tachyarrhythmias (VTs), triggered by acute coronary occlusion. Autonomic dysfunction, an important arrhythmogenic mechanism in this setting, is being actively investigated, aiming at the advent of preventive strategies. Recent experimental studies have shown vagal withdrawal after anterior myocardial infarction, coinciding with high incidence of VTs, followed by more gradual sympathetic activation coinciding with a second arrhythmia peak. This article summarizes recent knowledge on this intriguing topic, generating hypotheses that can be investigated in future experimental and clinical studies.

Keywords: Sudden cardiac death; Acute myocardial infarction; Ventricular tachyarrhythmias; Ventricular fibrillation; Delayed arrhythmogenesis; Ventricular tachycardia; Early arrhythmogenesis; Vagal activity; Sympathetic activity; Arrhythmogenic mechanisms

Core tip: Autonomic dysfunction in response to acute myocardial infarction is subject of continuous investigation. Recent experimental data indicated vagal withdrawal, followed by more gradual sympathetic activation, coinciding with early and delayed arrhythmogenesis, respectively. These findings call for further research on the pathophysiologic role of the autonomic nervous system on the ischemic ventricular myocardium.