SUDDEN CARDIAC DEATH IN HEART-FAILURE - THE ROLE OF ABNORMAL REPOLARIZATION

Congestive heart failure is a common, highly lethal cardiovascular dis order claiming over 200 000 lives a year in the United States alone. S ome 50% of the deaths in heart failure patients are sudden, and most o f these are probably the result of ventricular tachyarrhythmias. Metho ds designed to identify patients at risk have been remarkably unreward ing, as have attempts to intervene and prevent sudden death in these p atients. The failure to impact favorably on the incidence of sudden de ath in heart failure patients stems largely from a lack of understandi ng of the underlying mechanisms of arrhythmogenesis. This article expl ores the role of abnormalities of ventricular repolarization in heart failure patients. We will examine evidence for the hypothesis that alt eration of repolarizing K+ channel expression in failing myocardium pr edisposes to abnormalities in repolarization that are arrhythmogenic. The possible utility of novel electrophysiological and ECG measures of altered ventricular repolarization will be explored. Understanding th e mechanism of sudden death in heart failure may lead to effective the rapy and more accurate identification of patients at greatest risk.