Antitachycardia pacing in patients with implanted cardioverter defibrillators

Efficacy and safety of the use of antitachycardia pacing (ATP) function in 54 patients (age 18-54, mean age 62,2±11,5 years, 6 women) with cardioverter defibrillators implanted for prevention of sudden death. Duration of follow-up was 6-64 months (mean 27.3±8.6 months). Ischemic heart disease (IHD) was etiopathogenetic basis for development of ventricular rhythm disturbances in 38 (70.4%) patients. Arrhythmogenic right ventricular dysplasia (ARVD) was diagnosed in 8 (14.8%), hypertrophic cardiomyopathy - in 3, dilated cardiomyopathy - in 2, the Brugada syndrome - in 2 patients, and long QT syndrome - in 1 patient. Three regimens of ATP were studied - burst, ramp, ramp+ - which were activated in 22 patients (17 with IHD and 5 with ARVD). We registered 776 episodes of ATP occurring because of ventricular tachycardia (VT) in 20 of 22 patients with activated ATP. Overall efficacy of burst ATP was 49.1%; VT was not terminated or was accelerated in 43.2 and 7.6% of cases, respectively. Ramp ATP was effective in 44.3, ineffective - in 33.9, and caused VT acceleration in 21.8% of cases, what called forth fulfillment as a next step of shock therapy (cardioversion or defibrillation). ATP led to successful termination of VT in 67.5% of patients with IHD and to acceleration of arrhythmia - in 6% of episodes. Most effective type was ramp ATP which effectively terminated VT in 76.3% of cases, while efficacy of burst ATP was 61.4% (p<0.01). In patients with ARVD total efficacy of ATP was 25%, acceleration of VT during ATP was observed in 24% of cases; optimal was burst ATP, which efficacy was 33.9% - significantly higher than efficacy of ramp and ramp+ ATP (19.4 and 24.4%, respectively, p<0.005).