Implantation of a Cardioverter-Defibrillator After Coronary Artery Bypass Surgery

The implantable cardioverter-defibrillator (ICD) has been used in conjunction with surgical coronary revascularization for prevention of postoperative malignant arrhythmias. However, there is no consensus regarding which patient should receive concomitant insertion of the ICD system in a one stage (patches and generator) or two stage (patches, and subsequent implantation of the generator) procedure. To assess differences in hospital course and outcome, the authors studied 8 survivors of sudden death syndrome and 17 patients with preoperative ventricular tachycardia refractory to conventional antiarrhythmic therapy who underwent coronary revascularization and prophylactic implantation of an ICD system in either one or two stages. Patients with advanced coronary disease, poor ventricular function, and silent ischemia received the ICD system in one stage. Those with good ventricular function and well defined coronary pathology received only patches concomitant with myocardial revascularization. Seventy-nine percent of the patients with patches needed subsequent implantation of the ICD generator, as determined by postoperative electrophysiologic studies. There were three postoperative deaths unrelated to arrhythmias. There was no difference between the groups regarding the number of ICD discharges. It was concluded that the prophylactic use of the ICD system is an important adjuvant in the treatment of postoperative malignant arrhythmias for patients undergoing myocardial revascularization. The insertion of the ICD, however, should be based on pathophysiologic considerations and postoperative electrophysiologic findings. This may result in important savings in terms of unnecessary cost and operative procedures.