This report describes clinical, hemodynamic, and electrophysiologic characteristics of 18 consecutive survivors of sudden cardiac arrest due to idiopathic ventricular fibrillation (VF) between 1986 and 1996. Long-term data in relation to the prescribed therapy are presented. The mean age of the 18 patients was 48 +/- 14 years (median 49). Electrophysiologic studies showed a low inducibility of sustained ventricular tachyarrhythmias in 4 patients (22%). Treatment consisted of class III agents, beta blockers, or implantable cardioverter-defibrillators. Two patients were discharged without any therapy. Therapy control was undertaken either by serial drug testing or by the empirical approach. Serious complications of therapy occurred in 2 patients: 1 patient experienced a proarrhythmic effect of antiarrhythmic drug therapy, and the other patient received multiple inadequate defibrillator discharges due to a defect in the transvenous lead. All but 1 patient (94%) remained free of recurrences of sudden cardiac arrest during a follow-up time of 45 +/- 29 months (median 41). One patient died 2 weeks after surviving cardiac arrest due to intractable VF while receiving sotalol treatment. Therapy guided by electrophysiologic studies did not have any impact on survival. Adverse effects or noncompliance led to discontinuation of drug therapy in 7 patients after a mean period of 31 +/- 30 months. Without any treatment 9 patients remained without recurrences over 45 +/- 33 months. Because of the absence of risk factors for arrhythmia recurrence and criteria to select therapy, randomized prospective studies are warranted to assess the optimal therapies in these young, ostensibly healthy patients.