Heart block after transcatheter septal defect closure in infants under 10 kg: clinical outcomes and management options

Introduction and objectives: This study reviewed the management of heart block following transcatheter device closure of perimembranous ventricular septal defects in pediatric patients. Methods: We evaluated the follow-up and treatment of 1 patient who developed complete atrioventricular block and 5 patients who developed left bundle branch block (LBBB) from January 2019 through December 2023 after transcatheter ventricular septal defect closure in our clinic. Results: All patients who developed heart block weighed less than 10 kg. The only patient who developed complete atrioventricular block was successfully treated with temporary pacing, returning to sinus rhythm. In 2 of the 5 patients with LBBB, conduction disturbances were observed during the procedure, leading to termination without device release. One patient with postoperative LBBB returned to sinus rhythm following steroid therapy, and another one required surgical device removal. The patient with late-onset LBBB is still under close follow-up with serial ECG and echocardiography. Conclusions: Heart block after transcatheter closure of perimembranous ventricular septal defect is a serious complication, particularly in young patients with low body weight. Early detection and appropriate management, including procedural interruption, steroid therapy, and surgery when necessary, can lead to favorable outcomes. Careful patient selection and close follow-up are essential to minimize the risk of conduction disturbances.