CLINICAL-EXPERIENCE WITH TRANSVENOUS IMPLANTABLE CARDIOVERTER-DEFIBRILLATORS FOR TREATMENT OF MALIGNANT VENTRICULAR ARRHYTHMIAS

The need for thoracotomy has previously limited the use of the implant able cardioverter-defibrillator. Prior investigators have shown the ef ficacy and reduced risk of the transvenous implantable cardioverter-de fibrillator. In this study, we report our experience with the transven ous implantable cardioverter-defibrillator as a first-line system. Thi rty-four patients with mean age 63.2 +/- 10.3 years and mean ejection fraction 32.6 +/- 11.4 % underwent implantation of a transvenous cardi overter-defibrillator using an Endotak(TM) lead with or without a subc utaneous 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 le ss than or equal to 15.3 +/- 3.6J. Overall, 25 of 34 (74%) patients we re implanted with a single endocardial lead alone. In the group receiv ing a biphasic device 19 of 21 (90%) were successfully implanted with a single endocardial lead alone whereas in the group receiving a monop hasic device only 6 of 12 (50%) were successfully implanted with singl e 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-def ibrillator is safe and efficacious and that incorporation of biphasic waveform may lead to higher rates of implantation of single transvenou s lead alone without the need for subcutaneous patch..