BACKGROUND Previous studies have suggested that coronary artery bypass surgery is sufficient to prevent recurrence of sudden death in patients with critical coronary artery stenosis presenting with ventricular fibrillation or polymorphic ventricular tachycardia. We present our experience in patients with one or more episodes of sudden death associated with documented ventricular fibrillation or polymorphic ventricular tachycardia and severe operable coronary artery disease who underwent defibrillator implant at the time of bypass surgery. RESULTS Fifty-eight consecutive patients (age 63 +/- 8 years) were included in this study. Eighteen of the 58 patients had no evidence of previous myocardial infarction. The mean ejection fraction was 37 +/- 13%. All patients underwent electrophysiologic study before and after revascularization. At the time of first defibrillator discharge, each patient was reevaluated to exclude the presence of ischemia. The benefits of defibrillator implant were estimated comparing the projected survival based upon defibrillator discharge preceded by syncope or presyncope with survival curves generated including total death and sudden plus cardiac death. After a mean follow-up of 4.6 +/- 2 years, 22 patients received appropriate shocks preceded by syncope or presyncope, and an additional 19 patients received asymptomatic shocks. At 4 years, survival free of total death was 71.2%, and the projected survival was 58.8% (P < 0.05). Multivariate analysis showed that ejection fraction lower than 30% and induction of arrhythmia with one or two extrastimuli (S2, S3) were independent predictors for defibrillator discharge. None of the remaining variables including age, gender, number of bypasses, history of myocardial infarction, and type of arrhythmias induced were predictive for death and occurrence of shocks. CONCLUSIONS In patients with ventricular fibrillation and polymorphic ventricular tachycardia, bypass surgery does not protect from recurrence of life-threatening arrhythmias, and, as in our population, defibrillator implant may have significant impact on survival.