Impact of Subpectoral Implantation of the Implantable Cardioverter Defibrillators on Defibrillation Threshold

Abstract

Aims: the aim of this study is to find out the effect of subpectoral implantation of unipolar active case Implantable Cardioverter Defibrillators (ICD), on defibrillation threshold (DFT), compared to the conventional subcutaneous approach. Methods: unipolar, active case ICDs were implanted subcutaneously in 7 patients (group I), and subpectoraly in another 7 patients (group II); all patients were diagnosed with ischemic cardiomyopathy. DFT, shock lead impedance, R wave amplitude, slew rate, pacing lead threshold and pacing lead impedance were compared between the two groups. Results: DFT was significantly lower in group II, 14.8±5.5 vs 7.29±5.1 J (P=0. 017) in groups I and II respectively. Other parameters were comparable in the two groups. One patient with high DFT on subcutaneous ICD implantation showed an acceptable reduction of DFT when the device was implanted subpectoraly. Conclusion: reduction in DFT with subpectoral implantation of ICDs is among the benefits of this approach, which is an easy and workable approach to high DFT patients.