Intraoperative defbrillation threshold testing and postoperative long-term effcacy of cardioverter-defbrillator implantation

Abstract

T he a i m of th is st udy was to deter m ine the defbr i l la-tion threshold (DFT) of implantable cardioverter-defbrillators (ICDs) and outcomes of treatment. Sixty-four patients received cardioverter-defbrillator implantation.During implantation, the DFT was determined by the defbrillation safety margin (DSM). All patients were followed up for 12-48 months after the implantation. The overall DFT was 14.27±2.56 J and the DSM was 18.40±1.89 J. Malignant ventricular arrhythmias occurred in 42 patients following cardioverter-defbrillator implantation including 500 episodes of non-sustained ventricular tachycardia (VT) and 289 episodes of persistent VT. VT was treated using antitachycardia pacing (ATP); 265 episodes were treated successfully by a single ATP treatment (91.69%) and 12 episodes were treated successfully by two ATP treatments (4.15%). Twelve episodes were converted by low-energy electrical cardioversion (4.15%). A total of 175 ventricular fbrillation (VF) episodes were identifed, of which 18 episodes automatically terminated prior to treatment. In total, 146 episodes were converted by a single cardioversion with a defbrillation energy of 13.21±2.58 J and 11 episodes were converted by two cardioversions with a defbrillation energy of 16.19±2.48 J. It is safe and feasible to determine the DFT by DSM measurement during cardioverter-defbrillator implantation.