Postoperative atrioventricular block after surgery for congenital heart disease: incidence, recovery and risks

We aimed to determine the incidence of postoperative complete atrioventricular block, the time to recovery or permanent pacemaker implantation and the predictors for postoperative atrioventricular block after congenital heart surgery.

Patients who underwent open-heart surgery from January 2001 to January 2024 were analysed and predictors of atrioventricular block were identified using a logistic regression model.

Among 9765 congenital heart surgeries, 333 (3.4%) were complicated by atrioventricular block, and 193 patients (1.9%) underwent permanent pacemaker implantation. The highest rates of atrioventricular block were found in patients who underwent repair of congenitally corrected transposition of the great arteries (27.3%), followed by Konno procedure (20.0%), mitral valve replacement (16.0%) and arterial switch with closure of ventricular septal defect and arch repair (15.0%). In 134 (1.4%) patients with transient atrioventricular block, the median time to resolution was 4 days (interquartile range: 2-8 days). After 7 postoperative days, 75% had resolved, and after 12 postoperative days, 90% had resolved. Risk factors for the development of atrioventricular block were older age at operation (odds ratio: 1.012, P = 0.001), preoperative endocarditis (2.422, P < 0.001), longer aortic cross-clamp time (1.018, P < 0.001) and high-risk procedures (1.397, P = 0.012).

Postoperative atrioventricular block is not rare after congenital heart surgery, with more than half of them needing permanent pacemaker implantation. Older age at operation, preoperative endocarditis, longer aortic cross-clamp time and high-risk procedures were risks for the development of atrioventricular block. Pacemaker implantation should be delayed to the 12th postoperative day, when 90% of transient blocks have resolved.