Relative QT interval prolongation and electrical inhomogeneity of cardiac repolarization in childhood obesity

Abstract

ObjectiveStudies in adults demonstrated an association of obesity with prolongation of cardiac repolarization and an increased risk of ventricular arrhythmia and sudden cardiac death. The aim of this study was to evaluate potential alterations in cardiac repolarization in obese children. Methods83 lean and 132 obese consecutive healthy pediatric volunteers from the LIFE Child Study cohort were prospectively enrolled and their ECGs were analyzed. ResultsThere was a significant prolongation of corrected QT interval (p=0.001), T peak-to-end (p=0.001) and QT dispersion (p=0.001) in obese compared to lean children. The QT interval prolongation was more pronounced in girls than in boys (p=0.002), whereas there were no significant sex dependent differences in QT dispersion (p=0.18) or T peak-to-end (p=0.39). ConclusionChildhood obesity seems to be associated with a cardiac electrical inhomogeneity with the hypothetical potential for an increased arrhythmogenic risk. Furthermore, it causes a relative prolongation of the QTc interval compared to lean children with a more evident effect in females, yet without prolongation beyond the upper limits of normal.