Clinical experience with transvenous implantable cardioverter-defibrillators for treatment of malignant ventricular arrhythmias.

The need for thoracotomy has previously limited the use of the implantable cardioverter-defibrillator. Prior investigators have shown the efficacy and reduced risk of the transvenous implantable cardioverter-defibrillator. In this study, we report our experience with the transvenous implantable cardioverter-defibrillator as a first-line system. Thirty-four patients with mean age 63.2 +/- 10.3 years and mean ejection fraction 32.6 +/- 11.4% underwent implantation of a transvenous cardioverter-defibrillator using an Endotak lead with or without a subcutaneous patch. Twenty-one patients received a biphasic device and the remainder a monophasic device. Thirty-three of 34 patients (97%) were successfully implanted. The mean defibrillation threshold was than < or = 15.3 +/- 3.6J. Overall, 25 of 34 (74%) patients were implanted with a single endocardial lead alone. In the group receiving a biphasic device 19 of 21 (90%) were successfully implanted with a single endocardial lead alone whereas in the group receiving a monophasic device only 6 of 12 (50%) were successfully implanted with single endocardial lead alone (p < 0.05). There were no serious complications. One postoperative death was a result of end-staged congestive heart failure. We conclude that the transvenous implantable cardioverter-defibrillator is safe and efficacious and that incorporation of biphasic waveform may lead to higher rates of implantation of single transvenous lead alone without the need for subcutaneous patch.