Electrocardiographic repolarization parameters in children with arrhythmias and excessive body weight

In clinical diagnosis, electrocardiographic repolarization abnormalities with prolongation of QT and especially TpTe intervals are important for assessing the risk of malignant ventricular arrhythmias. The aim of the study was to compare the electrocardiological values of repolarization parameters in children with and without arrhythmias, according to body weight.

Repolarization parameters were compared in a group of children with excessive and normal body weight (BMI, Cole's index) with ventricular and supraventricular arrhythmias and in another group of children (matched for age and sex, with no arrhythmia and with normal weight) as the control group. The repolarization parameters TpTe, QTp and QT interval corrected Bazett (QTcB) and Fridericia (QTcF) formulas were measured in lead V5 of the 12-lead ECG.

The durations of TpTe and QTcF intervals were significantly longer in children with ventricular arrhythmias with abnormal body weight compared to children with supraventricular arrhythmias with abnormal body weight. Comparing children with normal weight between the ventricular and supraventricular groups, significant prolongation of only the TpTe interval was observed. Moreover, there were statistically significant differences (p < 0.0001) in the TpTe interval among the 5 groups: children with ventricular and supraventricular arrhythmia with abnormal and normal weight, as well as the control group depending on BMI and Cole's index.

In children with ventricular arrhythmia, only the TpTe parameter was significantly longer compared to children with supraventricular arrhythmia and children without arrhythmia, regardless of body weight. In children with arrhythmia, regardless of body weight, the TpTe parameter should be measured in addition to routine QT. Further studies on a larger scale are needed to assess the clinical importance of the TpTe interval in children with arrhythmias and excessive body weight.