ABSTRACT
<p><b>OBJECTIVE</b>To investigate the prognostic impact of heart block during the transcatheter closure of ventricular septal defect (VSD).</p><p><b>METHODS</b>Forty three patients developed complete left or right bundle branch block (CLBBB, CRBBB), incomplete left or right bundle branch block (ILBBB, IRBBB), and atrioventricular block (AVB) during and within 1 week post procedure were followuped at 1, 6, 12, 24, 36, 48 and 60 months post procedure. Electrocardiogram, dynamic electrocardiogram and transthoracic echocardiography were made.</p><p><b>RESULTS</b>Bundle branch block and atrioventricular block were detected in 26 patients (CLBBB n = 4, CRBBB n = 5, ILBBB n = 2, IRBBB n = 10 and third-degree AVB n = 5) during the transcatheter closure of VSD, and in 17 patients (CLBBB n = 5, CRBBB n = 2, first-degree AVB n = 3, second-degree I-type AVB n = 1 and third-degree AVB n = 6) within 1 week post procedure. Heart block disappeared in 33 patients (76.7%) before discharge, in 37 patients (86.1%) at 1 month and in 41 patients (95.4%) at 6 months post procedure. CLBBB or CRBBB was seen in two cases at 24 months after closure. There was no heart failure and serious cardiac dilatation during follow up.</p><p><b>CONCLUSION</b>The heart block occurred during the periprocedure period of transcatheter closure of VSD was a benign phenomenon without prognostic importance.</p>