Evidence of a Selective Increase in Cardiac Sympathetic Activity in Patients with Sustained Ventricular Arrhythmias

SUDDEN cardiac death due to a ventricular tachyarrhythmia is a major component of cardiovascular mortality. The immediate precipitants are unknown, but it is clear that the majority of patients have underlying organic heart disease, most often coronary artery disease 1 , 2 and poor left ventricular function. 3 4 5 Patients with left ventricular impairment and ischemic heart disease have a high prevalence of ventricular arrhythmias on ambulatory electrocardiographic monitoring and also have a high incidence of sudden cardiac death. 5 , 6 Although associations between ventricular arrhythmias, impaired left ventricular function, and sudden death are well established, the precise mechanisms involved are unclear. The level of cardiac sympathetic . . .