Selective conduction differences in children with isolated bicuspid aortic valve

Objective: Bicuspid aortic valve (BAV) is one of the most common congenital heart defects, yet the electrocardiographic features of isolated BAV in children have not been well characterized. We aimed to evaluate electrocardiographic parameters in pediatric patients with isolated BAV and to investigate whether early electrical changes are detectable before overt valve dysfunction. Materials and Methods: In this retrospective case-control study, 30 children with isolated and hemodynamically uncomplicated BAV were compared with 32 age- and sex-matched healthy controls. Via 12-lead surface electrocardiography, P wave parameters, QT and QTc intervals, QRS duration, axis measurements, and the QRS-T angle were assessed by two blinded investigators. For the ECG parameters, correction for multiple comparisons was applied with the Benjamini-Hochberg method. Results: The study included 30 children with BAV and 32 controls; median age was 142.5 versus 141.5 months, and male sex was present in 70.0% versus 75.0%, respectively. After correction for multiple comparisons, only the minimum duration of the P wave (q=0.005) and the dispersion of the P wave (q=0.008) showed significant differences between the groups; P minimum duration was higher and P wave dispersion was lower in the BAV group. No difference was found between the groups in the PR interval, QRS duration, the parameters of repolarization, and axis measurements. In the BAV group, aortic Z-scores were higher despite preserved systolic function of the left ventricle, and the left ventricular mass index did not reach statistical significance (p=0.058). Conclusion: Isolated pediatric BAV is associated with selective electrocardiographic changes at the level of atrial conduction, in the absence of a hemodynamic burden, while ventricular conduction and repolarization are not affected at this stage.