The study of QT and QTc intervals dispersion in sporting teenagers

Introduction Highlighting increasing of dispersion QT. QTc intervals can be a useful indicator for the risk of for the ventricular arrhythmias at young athletes. Objective to evaluate the QT interval dispersion in adolescent athletes regarding on the type of physical effort. Methods Subjects: 51 sporting teenagers (14–17 years old) organized in 2 lots: lot I: 25 endurance-trained athletes (runners, football-players); lot II: 26 strength-trained athletes (wrestlers, boxers). Control lot: 20 teenagers in the same age group, without any sign of cardiac suffering. ECGs were assessed on all the teenagers, athletes and non-athletes: in three successive cardiac ECG cycles,were calculated the QT interval dispersion (QTD) (the difference between maximum and minimum value of QT interval) and the QTc interval dispersion (QTcD)(Bazzet's formula). Results The average values of QTD and QTcD in the lots I and II were superior than the values in the control group but the difference is not statistic significant. Lot I: QTD: 43.54 ± 21,03 msec; QTcD: 50.81 ± 19.34 msec; Lot II: QTD: 48.23 ± 12.56 msec; QTcD:53.59 ± 17.21 msec; Control lot = QTD: 35.88 ± 10.22 msec; QTcD: 39.23 ± 14.81 msec. The highest values of QTinterval were found in strength-trained sporting teenagers. The highest values of QTD and QTcD were found in sporting teenagers from the second lot that it might be possible to have a higher ventricular arrhythmia risk. There was not any case with QT interval value longer than the normal. Conclusions At side of other parameters ECG, it is useful research screening of the QT interval and QTc interval dispersion during periodic controls, like indicator of the risk of the ventricular arrhythmias at sporting teenagers.