Identification of patients at increased risk for potentially malignant arrhythmias.

This review discusses the substrate and triggers of ventricular tachyarrhythmias or fibrillation and highlights the concepts that underlie risk stratification. Topics covered include the risks posed by arrhythmias in patients with: a) postinfarction, b) cardiomyopathy c) mitral valve prolapse, d) Wolff-Parkinson-White syndrome, and e) the long QT syndrome. Appropriate identification of patients at high risk for malignant ventricular arrhythmias requires subclassification by disease entity, historic information about syncopal episodes, noninvasive testing, and invasive electrophysiologic studies in selected patients.