Treatment strategies and prognosis of complete left bundle branch block after transcatheter closure of ventricular septal defect in pediatrics

Complete left bundle branch block (CLBBB) is a serious complication associated with transcatheter closure of perimembranous ventricular septal defect (pmVSD). The aim of the study was to evaluate various treatment strategies and prognosis of CLBBB after transcatheter closure of pmVSD in pediatric patients. Twenty five pediatric patients with CLBBB after transcatheter closure of pmVSD in our institution were retrospectively reviewed. Over a median follow-up of 6.7 (1.1–12.8) years, 14 cases were defined as early-onset CLBBB. Seven underwent early surgical device removal withing 1 month, 6 restored normal QRS interval, and 1 reverted to incomplete right bundle branch block. 3 underwent late surgical device removal (after 1 month of CLBBB discovery), 2 of them eventually underwent permanent pacemaker implantation, and 1 restored normal QRS interval. 4 cases received corticosteriod therapy, 2 restored normal QRS interval, 1 reverted to left anterior fascicular block, and 1 died of heart failure. 11 cases were defined as late-onset CLBBB and were given corticosteroid therapy as initial treatment. 2 restored normal QRS interval, 1 underwent surgical device removal and restored normal QRS interval, and 8 had persistent CLBBB (1 underwent cardiac transplantation, 1 underwent permanent pacemaker implantation, 4 had left ventricular enlargement with reduced ejection fraction, 2 maintained normal left ventricular size and function). Compared with patients who did not receive early device removal, patients who underwent early device removal were less likely to experience adverse events [0% (0/8) vs.53% (9/17), P = 0.022]. For patients who only received corticosteroid therapy, patients who were free from adverse events had significantly shorter QRS index [(7.90 ± 0.80) vs. (9.40 ± 1.23) ms/(kg/m2), P = 0.032]. Early surgical device removal was associated with favorable prognosis of CLBBB after pmVSD device closure. Corticosteroid therapy might be an alternative treatment strategy for CLBBB with relatively narrow QRS interval.