Long-term follow-up of patients with relatively high effective defibrillation threshold during cardioverter defibrillator implantation with endocardial leads.

OBJECTIVE: We evaluated the 15-year outcome of patients with an implantable cardioverter defibrillator (ICD) and a relatively high defibrillation threshold (DFT). METHODS: After ICD implantation, patients were allocated to 3 groups: DFT 24-25 J (16 patients), effective defibrillation with 18-20 J (20 patients) and DFT <15 J (118 patients). An abbreviated DFT test was used during the implantation. The follow-up duration was 15.5 years. RESULTS: There was no significant difference between the survivals of the 3 groups, with a mean survival of 7.30 +/- 4.51 years. In the ventricular fibrillation zone, 99.69, 100 and 100% of the episodes were successfully defibrillated in the 3 groups, respectively. In the ventricular tachycardia zone, 83.24, 92.86 and 95.39% of the episodes were terminated with pacing therapy. The small differences between the groups were not statistically significant. The testing method did not have an impact on survival or therapy success rate. CONCLUSIONS: A 24-joule DFT with a 10-joule safety window is safe during 15 years of follow-up.