Recent studies have shown that the Tp-e interval, which on an electrocardiogram (ECG) is the interval between the peak and the end of the T wave, can be used as an index of transmural dispersion of ventricular repolarisation (TDR). Both Tp-e/QT and Tp-e/QTc ratios have also been used in that capacity. However, these novel repolarisation indices have not previously been studied in children with acute rheumaticcarditis (ARC).
A hundred and thirty-nine children who were diagnosed with ARC and 153 age- and gender-matched healthy controls were retrospectively reviewed. Twelve-lead ECGs were used to evaluate P-wave, QT and QTc dispersions, Tp-e interval, and Tp-e/QT and Tp-e/QT ratios.
The mean age of the patients was 10.9 ± 2.4 years. The P-wave, QT and QTc dispersions were significantly higher in patients compared to the healthy control subjects. The Tp-e interval, and Tp-e/QT and Tp-e/QTc ratios were also significantly increased in patients compared to the controls. When the patients were compared in terms of either one- or two-valve involvement, we found no difference between the groups regarding P-wave, QTd and QTc dispersions, Tp-e interval, and Tp-e/QT and Tp-e/QT c ratios. There was no correlation between acute-phase reactants, white blood cell count and these repolarisation parameters.
This study showed that the new transmural dispersion of ventricular repolarisation parameters, Tp-e interval, Tp-e/QT ratios and QTd were increased in children with ARC. Prolongation of the Tp-e interval and an increased Tp-e/QT ratio might be useful markers for predicting myocardial involvement in children with ARC.