P1060Predictors of successful catheter ablation of ventricular arrhythmias in pediatric patients: 12 years experience in 532 pediatric patients

The aim: to determine the efficacy of catheter ablation based on comprehensive evaluation of the endocardial mapping results, arrhythmia substrate localization, and prediction of treatment success in children with ventricular arrhythmias (VA). Methods: The study comprised 532 pts with idiopathic ventricular arrhythmias who received catheter ablation of the arrhythmogenic focus in one hospital from 2003 to 2014. Patients were divided into two groups for validation of novel protocol of endocardial mapping. Group 1 comprised 119 patients aged 8–17 years: 65 (54.6%) male and 54 (45.4%) female. In this group, choice of a site for radiofrequency catheter ablation (RFA) was based on the conventional criteria for endocardial mapping. Group 2 comprised 413 patients aged 5–18 years: 254 (61.5%) male and 159 (38.5%) female. In these patients, a site for RFA was chosen according to the method based on the calculation of the probability for successful treatment. Results: Implementation of novel endocardial mapping protocol in our study increased the efficacy of catheter ablation for ventricular arrhythmias in children. We revealed that the efficacy of catheter ablation was 73.11% and 89.83% in Groups 1 and 2, respectively (χ2 = 21.57, df = 1, p < 0.00001, Cramer’s V = 0.197). Conclusions: An optimal protocol of the endocardial mapping for VA in children should include calculation of the probability of successful CA based on the comprehensive evaluation of EM results. Implementation of the approach to RFA of the VA based on a comprehensive evaluation of the EM results and prediction of the probability of successful intervention may increase the efficacy of treatment for VA in children.