Abstract: Abstract Objective:To evaluate the effectiveness and safety of radiofrequency catheter ablation (RFCA) of accessory pathways (APs) in infants. Methods:Infants younger than 1 year old were evaluated retrospectively, who underwent RFCA in our institution between January 1, 2015 and June 30, 2019. Indications for RFCA included drug-refractory atrioventricular reentrant tachycardia (AVRT) or cardiomyopathy induced by APs. All procedures were performed using a modified low dose imaging protocol of fluoroscopy. Results:A total of eight infants were included, with median age of 6.5 months and weight of 7.7kg. The electrophysiology study confirmed 1 AP in each 7 patients and 2 APs in 1 patient, of which 5 were right lateral; 3 were left lateral and 1 was left posteroseptal. The AP was manifested in 4 patients with Wolff-Parkinson-White syndrome and concealed in another 4 patients. Median fluoroscopy time was 11.2 minutes and dose-area product was 15.7 μGy. m2. The acute success rate was 100%. After the median follow-up period of 15 months, no tachycardia recurred. One patient developed late mitral valve perforation, which was successfully repaired by surgery and no other complications occurred. Conclusion:RFCA could effectively cure infants with drug-refractory arrhythmias induced by APs, however, the indications should be taken seriously and proper procedural modifications might be needed to avoid ablation complications as far as possible.