The commonest approach to preventing sudden cardiac death has been by the use of drugs that suppress ventricular ectopy. The rational for this approach is based upon an association between the presence or frequency of ventricular arrhythmia and subsequent mortality in several studies. None of the randomized controlled studies of numerous 'classical' antiarrhythmic agents (other than beta-blockers, which have only a modest effect on arrhythmia suppression) have demonstrated a reduction in sudden or non-sudden cardiac mortality. Indeed, in the recent Cardiac Arrhythmia Suppression Trial (CAST), two class Ic anti-arrhythmic agents demonstrated a 2.5 fold increase in the risk of sudden and non-sudden cardiac deaths despite excellent suppression of ventricular arrhythmia.