Clinical Predictors of Successful Anti-tachycardia Pacing for Ventricular Arrhythmia Termination

Background: Anti-tachycardia pacing (ATP) is a fast and safe method for terminating ventricular tachycardia (VT). Implantable cardioverter defibrillator (ICD) shocks are unpleasant, stressful experiences that have been associated with higher mortality rates than ATP. Determining the factors enhancing the efficacy of ATP therapies can minimize the appropriate ICD shocks. Objectives: In this study, we investigated the factors anticipating the success rate of ATP. Methods: This descriptive cross-sectional study was carried out among 60 patients referring to our center for regular ICD device analysis. These patients had at least one episode of appropriate ATP therapy in their analysis. The VT morphologic characteristics were obtained from stored far-field intracardiac electrogram (EGM). The VT episodes and native QRS were classified into non-Q or Q categories based on their EGM morphologies. Results: ATP was successful in 38 (63.3%) cases. Age, sex, history of ischemic heart disease and diabetes, type of device and cardiomyopathy (ischemic or dilated), antiarrhythmic drugs, left ventricular ejection fraction, and EGM characteristics did not predict ATP success. Conclusions: It seems that neither the demographic factors nor the morphologic characteristics of VT EGMs can predict the efficacy of ATP therapy.