Idiopathic right ventricular outflow tract arrhythmia: gender difference in the origin of ventricular arrhythmia and influence factors of ablation results

Objective The purpose of this study was to analyze the clinical feature, electrophysiological characteristics and results of radiofrequency catheter ablation of 468 patients with idiopathic right ventricular outflow tract arrhythmia (IRVOTA) , and to explore the gender differences in ventricular arrhythmia originating from the right ventricular outflow tract (RVOT) and factors affecting the results of radiofrequency ablation. Methods We retrospectively reviewed 468 consecutive patients who underwent endocardiac electrophysiologic study and radiofrequency catheter ablation due to IRVOTA ventricular arrhythmia in Fuwai Hospital from February 2009 to January 2013. There were 185 male and 283 female patients. The electrophysiological characteristics and the incidence and the results of radiofrequency catheter ablation of ventricular arrhythmias originated from six different sites were analyzed. The multivariate Logistic regression analysis were used to analyze gender difference in factors affecting the results of radiofrequency catheter ablation. Results In our study, female patients (283) were more common than male patients (185, 60.5% vs.39.5%) . The sex distribution in each origin of ventricular arrhythmia was different. There were significantly more male patients than female patients in free wall origin (11.4% vs.6.0%, P=0.04) . In the case of epicardial origin, the percentage of male patients were also significantly higher than that of female patients (8.6% vs.4.2%, P=0.02) . There were little more female patients in the septal origin without significant difference (56.9% vs. 48.6%, P=0.057) . The acute success rate of ablation in female patients was significantly higher than that in male patients (92.2% vs. 84.9%, P=0.01) . Gender differences also existed in factors affecting the results of ablation. For female, epicardia origin (OR 6.41, 95%CI: 1.26-32.70, P=0.017) and RVOT-AO origin (OR 8.88, 95%CI: 2.15-36.67, P=0.002) were the independent factors of ablation failure. However, for male, epicardia origin (OR 12.17, 95%CI: 3.19-46.39, P<0.001) was the only independent factor of ablation failure. Conclusion There were gender differences in different origins of ventricular arrhythmia in IRVOTA and results of radiofrequency ablation have gender differences. Key words: Ventricular arrhythmia; Right ventricular outflow tract; Gender; Radiofrequency catheter ablation