Abstract: Objective To explore the efficacy and safety of radiofrequency catheter ablation for ventricular arrhythmias originated from the right ventricular outflow tract(RVOT-VAs)and its influencing factors.Methods According to the success of a single operation or not,256 patients with RVOT-VAs undergoing radiofrequency catheter ablation were divided into successful single operation group(196 cases)and unsuccessful single operation group(60 cases),then general data and operational data of them were compared.Binary logistic regression analysis was performed to evaluate factors that affect the efficacy and safety of operation.Results In 256 patients,immediate success rate,single operation success rate and recurrence rate were 88.3%,76.6% and 13.2% respectively.Proportion of patients combined with hypertension and organic heart disease,QRS waves with various forms,surgical complications and pericardial tamponade in successful single operation group were lower than those in unsuccessful single operation group（P<0.05）.Results of binary logistic regression analysis showed that combining organic heart disease,lack of experience for operators and target site of catheter ablation locating in free wall were independent risk factors for failure of single operation（P<0.05）.Persistent ventricular tachycardial and target site of catheter ablation locating in free wall were independent risk factors for immediate failure of the first operation（P<0.05）.Combining organic heart disease,lack of experience for operators,target site of catheter ablation locating in free wall and QRS waves with various forms were independent risk factors for recurrence after the first operation（P<0.05）.Advanced age and lack of experience for operators were independent risk factors for complications during the first operation（P<0.05）.Conclusion There is high success rate and safety of radiofrequency catheter ablation treating RVOT-VAs.Combining organic heart disease,target site of catheter ablation locating in free wall and the operator’s experience are important factors which affect the efficacy and safety.

Key words: Right ventricular outflow tract, Ventricular arrhythmia, Radiofrequency catheter ablation, Efficacy, Safety