Trials of the automatic implantable defibrillator in man. A three-year program report

Since February, 1980, 65 survivors of multiple arrhythmic cardiac arrests unresponsive to therapy were referred for implantation of the automatic defibrillator. In 37 patients (Group I), automatic defibrillator implantation alone was performed by subxiphoid insertion (20 patients) or thoracotomy (17 patients). In another 28 patients (Group II), implantation was combined with definitive cardiac procedures - coronary artery bypass grafting in seven patients, bypass grafting and mitral valve replacement in four patients, and left ventricular aneurysmectomy with endocardial resection in 17 patients. There were no surgical deaths in Group I; four operative deaths occurred in Group II. The longest follow-up has been 34 months, average 15.6 months. Following hospital discharge, 44 episodes of automatic out-of-hospital resuscitation were observed in 11 Group I patients. Similarly, four resuscitations were observed in two Group II patients. Hypothetical survival curves based on the assumption that these out-of-hospital resuscitations were lifesaving indicated expected 1 year survival rates of 45% in Group I and 85% in Group II. Excluding the perioperative deaths that were unrelated to the defibrillator, the actual 1 year survival rates observed were 75% and 95% in Groups I and II, respectively. Although definitive operation markedly reduced the number of out-of hospital arrhythmic episodes, the automatic defibrillator appears to increase survival both when implanted alone and when used in combination with cardiac procedures.