Effect of Postoperative Arrhythmia in Children Less Than 18 Years of Age Following Congenital Cardiac Surgery: A Prospective Study

Background Postoperative arrhythmias are common among children after congenital cardiac surgery, potentially compromising hemodynamic stability and postoperative recovery. This study aimed to assess the impact of arrhythmias on hemodynamics and clinical outcomes. Material and Methods Three hundred and twenty-nine children under 18 years of age undergoing congenital cardiac surgery were studied prospectively. In addition to standard postoperative hemodynamic monitoring, electrical cardiometry (ICON ® ) was used to assess hemodynamic parameters across time points (prearrhythmia, during arrhythmia, and postarrhythmia). Repeated measures were analyzed using Friedman test followed by Wilcoxon signed-rank test with Bonferroni correction for pairwise comparisons. Poisson regression with robust variance estimation was used to identify independent predictors and calculate incidence rate ratios (IRR). Results Postoperative arrhythmias occurred in 53/329 patients (16.1%). Junctional ectopic tachycardia (34%, [18/53]) and supraventricular tachycardia (30.2%, [16/53]) were the most common. Arrhythmias were associated with low cardiac output (IRR 3.43; 95% confidence interval [CI] 2.27-5.17; P < .001), ventricular dysfunction (IRR 2.55; P < .001), acute kidney injury (IRR 2.01; P = .006), and liver dysfunction (IRR 4.56; P = .002) on unadjusted analysis. However, these associations were attenuated after adjustment for prearrhythmia hemodynamic variables like central venous pressure (CVP) and vasoactive-inotropic score (VIS) on multivariable analysis. Elevated CVP, VIS, and hypokalemia were predictors of arrhythmia. Conclusions Arrhythmias occurred in approximately one-sixth of children following congenital cardiac surgery and were associated with adverse hemodynamic changes, organ function, and recovery. However, these associations were attenuated after adjustment for prearrhythmia hemodynamic variables (CVP and VIS), suggesting that arrhythmia may reflect underlying instability rather than a primary causal factor.