The problem of refractory life-threatening ventricular tachyarrhythmias in elderly patients has not been previously studied. To determine if clinical, anatomic, or electrophysiologic variables and prognosis are significantly different in elderly subjects, 49 elderly (68 to 84 years) and 44 younger (44 to 53 years) survivors of refractory symptomatic ventricular tachycardia and/or ventricular fibrillation secondary to coronary artery disease were studied. Elderly patients displayed more extensive anatomic coronary artery disease, with 80 percent having three-vessel disease in comparison with 30 percent of the younger patients (p less than 0.001). Prior myocardial infarction, heart failure, and cardiomegaly were more common in the elderly group (p less than 0.01, p less than 0.001, and p less than 0.034, respectively), whereas angina was more common in the younger group (p less than 0.001). In 55 percent of the elderly patients and 58 percent of the younger patients, electrophysiologic testing demonstrated inducible sustained ventricular tachycardia that required treatment with an investigative antiarrhythmic drug and/or cardiac surgery, including implantation of an automatic defibrillator. Elderly patients tolerated aggressive evaluation as well as did younger patients, and despite the difference in clinical and anatomic findings, long-term survival curves were similar, although the probability of survival at 20 months was 62 percent in the elderly and 80 percent in the younger patients. This difference in early survival is explained by eight surgical deaths in the elderly group, compared with two in the younger group.