Surgical Outcomes of Congenital Heart Disease in Down Syndrome: Tertiary Center Experience-Focus on the Electrical Conduction System.

To document outcomes of cardiac surgical repair in Down syndrome (DS) patients with specific focus on the associated electrical conduction morbidities, ultimately leading to a higher incidence of pacemaker implantation (PMI). A retrospective study conducted between 2011 and 2020. A total of 167 DS patients undergoing 204 surgeries were included. The mean gestational age (GA) and mean weight were 37.3 weeks and 5.5 kg, respectively. Complete atrioventricular septal defect (AVSD) was the most common diagnosis. Pre-operative ECG revealed superior axis deviation (SAD) in 92 and 32% of patients with AVSD and isolated perimembranous ventricular septal defect (VSD), respectively (p < 0.01). Postoperative right bundle branch block (RBBB) was observed in 83 and 55% of patients with AVSD and following perimembranous VSD repair, respectively (p = 0.04). Ten patients underwent post-operative pacemaker implantation (PMI). Reintervention rate was around 8.9%. Three mortalities were encountered throughout the study period, 2 of which were in-hospital deaths. Low mortality was observed, however, a higher rate of PMI requirements noted with risk factors including lower age and weight.