Efficacy and safety of implantable cardioverter defibrillator avoiding routine defibrillation threshold testing

Abstract

Objective To evaluate the efficacy and safety of implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy-defibrillators (CRT-D) avoiding defibrillation threshold (DFT) testing when treating ventricular tachycardia (VT) or ventricular fibrillation (VF). Methods We analyzed a continuous database of the 21 patients who had avoided DFT during ICD implantation from Oct. 1999 to Aug. 2008. Follow-up data were completed and analyzed in the 21 patients with ICD implantation. Results ICDs were implanted successfully in 17 patients with VT or VF, and CRT-D were implanted successfully in 4 myocardiopathy patients with severe heart failure who avoided DFT during ICD or CRT-D implantation. Eight patients accepted DFT 1 week later, VT or VF was not induced in 3 patients (37.5%). During the mean follow-up of 1 ∼ 7 (4.2 ± 1.9) years, malignant ventricular arrythmia was recorded in 16 patients. Among them, 89 episodes were successfully terminated by defbrillation (100%), 120 VT events were terminated by the first run of antitachycardia pacing (51.1%) and 22 by low engery cardioversion (59.2%). All paitents took antiarrhycardia drugs after ICD or CRT-D implantation. No patient died from malignant ventricular arrythmia during the follow-up. Conclusion No application of routine DFT may aviod complications associated with DFT during ICD or CRT-D implantation. ICD or CRT-D implantation may effectively treat fatal ventricular tachyarrhythmias and prevent sudden cardiac death.