Our primary aims were to describe the contemporary epidemiology of postoperative high-grade atrioventricular block (AVB), the timing of recovery and permanent pacemaker (PPM) placement, and to determine predictors for development of and recovery from AVB.

Patients who underwent congenital heart surgery from August 2014 to June 2017 were analyzed for AVB using the Pediatric Cardiac Critical Care Consortium registry. Predictors of AVB with or without PPM were identified using multinomial logistic regression. We used these predictors to model the probability of PPM for the subgroup of patients with intraoperative complete AVB.

We analyzed 15,901 surgical hospitalizations; 422 (2.7%) were complicated by AVB and 162 (1.0%) patients underwent PPM placement. In patients with transient AVB, 50% resolved by 2 days, and 94% resolved by 10 days. In patients who received a PPM, 50% were placed by 8 days and 62% were placed by 10 days. Independent risk factors associated with PPM compared with resolution of AVB were longer duration of cardiopulmonary bypass (relative risk ratio, 1.04; P = .023) and a high-risk operation (relative risk ratio, 2.59; P < .001). Among patients with complete AVB originating in the operating room, those with the highest predicted probability of PPM had a PPM placed only 77% of the time.

In this cohort, postoperative AVB complicated almost 3% of congenital heart surgery cases and 1% of patients underwent PPM placement. Because almost all patients (94%) with transient AVB had resolution by 10 days, our results suggest there is limited benefit to delaying PPM placement beyond that time frame.