Life-threatening arrhythmias and therapy

Abstract

Considerable attention has been paid in recent years to the outcomes of clinical trials of implantable cardioverter defibrillators (ICDs). Some of these studies have shown a significant benefit of ICDs on the survival rates within specific sub-groups. However, the broader picture shows that, of the total numbers of sudden cardiac deaths (SCDs) that occur each year (about 300 000 in the USA), the vast majority do not occur in patients who are at very high risk — the type of patients that tend to form the populations of ICD trials [1,2] (Fig. 1). Thus, while the defibrillator trials can be regarded as successful, they have not addressed the larger part of the SCD problem. To make a major impact on the overall incidence of SCD, those patients who comprise the major at-risk population need to be identified, and a prophylactic treatment strategy implemented.