Catheter ablation of ventricular tachycardia is a procedure of last resort in critically ill patients. The Percutaneous Cardiac Mapping and Ablation Registry was able to collect data on 88 patients undergoing ablation of ventricular tachycardia foci. The mean following interval for the group was 10 +/- 8 months. Results were divided into three categories: Group I patients remained asymptomatic and were on no antiarrhythmic medications (33%); Group II remained asymptomatic and took antiarrhythmic agents (38%); Group III patients were considered unsuccessful and consisted of 29 percent of the total. More than one-third of patients received two shocks; the remainder received from one to five shocks. Overall mortality included four procedure-related deaths and total follow-up mortality was 25 percent. Catheter ablation for ventricular tachycardia should be undertaken only in highly specialized centers with an expert and experienced electrophysiologist with immediate surgical back-up available.