Sudden death in dilated cardiomyopathy

The purpose of this review is to examine the potential contribution of arrh ythmia to the occurrence of sudden death in dilated cardiomyopathy (DCM) an d to discuss current treatment options. We performed a search of the MEDLIN E database from 1985 to the present and the reference citations of selected articles pertaining to the prognostic significance, management, and pathop hysiology of arrhythmias in DCM. A large proportion of patients with DCM di e suddenly, most secondary to ventricular arrhythmia and a smaller proporti on due to bradyarrhythmia. The presence and severity of ventricular ectopy may predict risk for sudden death, but the role of electrophysiologic study and signal-averaged electrocardiography in further risk stratifying patien ts remains uncertain. Abnormalities of the autonomic nervous system and ren in-angiotensin-aldosterone axis appear to promote the occurrence of ventric ular arrhythmias. Angiotensin-converting enzyme inhibitors improve overall mortality in congestive heart failure, and the use of direct angiotensin-re ceptor antagonists is currently being studied. In addition, beta-receptor a ntagonists appear to improve morbidity and may prove to improve mortality i n heart failure as well. Other interventions still under investigation incl ude amiodarone and the implantable cardioverter-defibrillator. The underlyi ng pathophysiology of sudden death in DCM involves primarily ventricular ta chyarrhythmia. Angiotensin-converting enzyme inhibitors remain a mainstay o f improving overall mortality, while further study on the roles for newer d rugs and devices is ongoing.