The Efficacy Of Implantable Cardioverter Defibrillator Avoiding Defibrillation Threshold Testing During Its Implantation

Objective: The efficacy and safety of implantable cardioverter defibrillator(ICD) treating ventricular tachycardia(VT) or ventricular fibrillation(VF) were evaluated which avoided defibrillation threshold testing(DFT) during ICD or cardiac resynchronization therapy-defibrillators(CRT-D) implantationMetheds: We analyzed a continuous database of 23 patients who have avoid DFT during ICD implantation from Oct. 1999 to Apr. 2009. follow-up data were completed and analyzed in 21 patients with ICD implantation.Results: ICDs were implanted successfully in 19 patients with VT or VF, and CRT-Ds were implanted successfully in 4 myocardiopathy patients with sereve heart failure which avoided DFT during ICD or CRT-D implantation. 3 patients accepted DFT 1 week later, but VT or VF was not induced in 1 patients (33.3%). During the mean follow-up of 4.2±1.9(1～10) years, malignant ventricular arrythmia were not recorded in 5 patients, while episodes of VTs or VFs occured 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 (50.8%) and 22 by low engery cardioversion (59.1%).11 patients were prepared to undergo DFT testing but VT or VF was not induced in 2 patients (18.1%). During the follow-up, malignant ventricular arrythmia was not recorded in 3 patients, while episodes of VTs or VFs occured in 8 patients. Among them, 28 episodes were successfully terminated by the first defbrillation (92.5%), 66 VT events were terminated by the first run of antitachycardia pacing (51.5%) and 12 by low engery cardioversion (58.3%). 1 shock was mistakenly delivered in 1 patient during atrial fibrillation with rapid ventricular response. All paitents took antiarrhycardia drugs after ICD or CRT-D implantation. No patient died from malignant ventricular arrythmia during follow-up period. The rates of successful termination of VT/VF episodes by ICD shocks were the same for both patient groups.Conclusions: No DFT may aviod complications associated with DFT during ICD or CRT-D implantation, ICD implantation may effectively treat the fatal ventricular tachyarrhythmias and prevent sudden cardiac death even if no DFT routinely during ICD implantation.