In multivariate analysis, preoperative digoxin exposure (odds ratio [OR] 2.4, 95% confidence interval [CI] 1.3-4.4), aortic cross-clamp time (OR 1.08, 95% CI 1.04-1.11), ventricular septal defect closure (OR 2.2, 95% CI 1.2-4.1), and a common polymorphism in the gene encoding connexin-40 (GJA5 rs10465885 TT genotype; OR 2.1, 95% CI 1.2-3.8) were independently associated with postoperative CHB.