[Clinical characteristics of 42 children with focal atrial tachycardia originated from the right atrial appendage].

Objective: To investigate the feature and treatment of atrial tachycardia (AT) originated from right atrial appendage (RAA) in children. Methods: The data of 42 children with AT originated from RAA, who were admitted the First Hospital of Tsinghua University from January 2010 to September 2022 were analyzed retrospectively.The clinical characteristics, treatment and efficacy were analyzed. The children were divided into tachycardia cardiomyopathy group and normal cardiac function group. The differences in the ablation age and the heart rate during AT between two groups were compared by independent sample t-test. Results: Among 42 children, there were 20 males and 22 females. The age of onset was 2.7 (0.6, 5.1) years. Their age at radiofrequency ablation was (6.5±3.6) years, and the weight was (23.4±10.0) kg. Thirty-two children (76%) had sustained AT. The incidence of tachycardia cardiomyopathy was 43% (18/42). Compared to that of the normal cardiac function group, the ablation age and the heart rate at atrial tachycardia of the tachycardia cardiomyopathy group were higher ((8.1±3.8) vs. (5.3±3.1) years, t=-2.63, P=0.012; (173±41) vs. (150±30) beats per minute, t=-2.05, P=0.047. Thirty-eight children (90%) responded poorly to two or more antiarrhythmic drugs. The immediate success rate of radiofrequency ablation (RFCA) was 57% (24/42), and the AT recurrence rate was 17% (4/24). Twenty-two children underwent RAA resection, and their AT were all converted to sinus rhythm after the surgery. During the RAA resection, 10 cases of right atrial appendage aneurysm were found, 9/18 of which failed the RFCA. Conclusions: The AT originated from the RAA in children tend to present with sustained AT, respond poorly to antiarrhythmic drugs, and has a low success rate of RFCA as well as high recurrence rate. Resection of the RAA is a safe and effective complementary treatment.