Automatic defibrillation in man: is it feasible?

Twenty-eight patients who survived multiple arrhythmic cardiac arrest refractory to medical therapy underwent implantation of the automatic defibrillator without additional antiarrhythmic surgery. Lateral thoracotomy was used for implantation in 14 patients and the subxiphoid technique was used in 14. There was no operative mortality and surgical complications were minimal. The longest follow-up was 29 months and the average was 14 months. The implanted device correctly identified and reverted 50 episodes of spontaneous malignant ventricular tachyarrhythmias in six hospitalized patients. After discharge, 20 episodes of automatic out-of-hospital resuscitations occurred in eight patients. Kaplan-Meier survival curves, based on the assumption that out-of-hospital defibrillations would otherwise have been lethal, indicated an expected 1 year mortality of 60 percent. Seven deaths were in fact observed in this period for an actual mortality rate of 30 percent. We conclude that automatic defibrillation is clearly feasible in man and appears to increase survival in selected high-risk patients.