ABSTRACT
Sudden death, often as a consequence of lethal ventricular arrhythmias, is an important
cause of cardiovascular mortality, accounting for 300,000-400,000 deaths annually in the
United States (1). Nearly 80% of individuals who die suddenly from cardiac causes have
evidence of underlying coronary artery disease or prior myocardial infarction (2,3).
The risk of sudden death increases with worsening left ventricular function and heart
failure symptoms (4,5). As a consequence, patients with advanced heart failure are at
particularly high risk for sudden cardiac death (SCD). In the Framingham Heart Study, the
age-adjusted sudden death rate for patients with heart failure was nine times that of
the general population (6). Despite marked advances in medical therapy, it is estimated
that roughly one-half of patients with depressed left ventricular ejection fraction (LVEF)
and congestive heart failure (CHF) will die suddenly or require resuscitation from
a cardiac arrest (7).
