First experience with a new nonthoracotomy defibrillation lead system

The clinical efficacy and safety of a new nonthoracotomy defibrillation lead system (TVL lead system, Ventritex, Inc., Sunnyvale, Calif.) was studied in patients with ventricular tachycardia or fibrillation. Implantation of the TVL lead system and a Cadence pulse generator (Ventritex, Inc.) was attempted in 27 patients. A subcutaneous patch lead was added if required to achieve adequate defibrillation energy. Patients were monitored for an average of 6 ± 4 months (range 1 week to 14 months). Implantation was successful in 26 patients (96%). Twenty-three of those patients (88%) were implanted in a lead-alone configuration; the remaining three (12%) required a subcutaneous patch lead. The mean defibrillation threshold was 401 ± 120 V (12 ± 7 J) at implantation, 467 ± 134 V (15 ± 8 J) at predischarge testing, and 452 ± 151 V (14 ± 9 J) at 4-month follow-up. The mean defibrillation threshold at 4 months was not significantly different from that at implant. No deaths, sensing anomalies, infections, lead fractures, or lead dislodgments occurred. One patient required addition of a subcutaneous patch 4 months after device implantation because of an elevated defibrillation threshold. Eight patients (31%) experienced 545 spontaneous arrhythmic episodes, and all episodes were successfully terminated by the device. In conclusion, the TVL lead system combined with Cadence tiered-therapy defibrillator has a high success rate and low complication rate, and it can be recommended for treatment of patients with life-threatening ventricular tachyarrhythmias.