[Clinical and prognostic analysis of accessory pathway-induced dilated cardiomyopathy after catheter ablation in children].

Objective: To investigate the clinical characteristics and prognostic factors after catheter ablation of accessory pathway (AP)-induced dilated cardiomyopathy (DCM) in children. Methods: Data were collected and analyzed on 147 consecutive pediatric patients (81males and 66 females), who hospitalized in our pediatric heart center between January 2009 and August 2018 and received catheter ablation for ventricular pre-excitation (right AP). Thirty-one children were diagnosed as AP-induced DCM and 116 children with normal cardiac function served as control. Data including clinical characteristics, electrocardiogram (ECG), echocardiography, electrophysiological examination (EPS), successful ablation and follow up were analyzed. Results: The median age at first examination was 3.07 (0.09, 5.83) years. The pre-hospital misdiagnosis rate was 87.1% (27/31). The incidence of the AP-induced DCM was 21.1% (31/147) and the rate of right anterior free wall accessory pathway (AP) was the highest (50.0%, 10/20). AP-induced DCM was more common in right free wall Aps (41.9%, 13/31) and right anterior free wall (32.3%, 10/31). 48.4% (15/31) cases had no supraventricular tachycardia (SVT). EPS showed that 29% (9/31) of the AP did not have retrograde conduction. The median follow-up time after successful catheter ablation was 8 (2, 36) months of AP-induced DCM group, LVDd was significantly decreased ((41.6±12.8)mm vs. (45.6±13.9)mm, P< 0.01) and LVEF ((56.2±11.8)% vs. (40.8±12.5)%, P< 0.01) was significantly increased after ablation. Cox regression analysis showed that LVEF was the predictor of the duration of cardiac function recovery ( HR =1.08, 95 %CI 1.01-1.15, P= 0.03). Conclusions: Misdiagnosis rate is high for children with AP-induced DCM, leading to the delayed treatment. All of the AP-induced DCM occurred in right APs and right anterior free wall APs is the highest. Right free wall APs and right anterior free wall are most common in AP-induced DCM. Catheter ablation is a safe and effective treatment option for these patients. The lower the LVEF, the longer the cardiac function recovery.