Behavior of repolarization variables during exercise test in the athlete's heart

Abstract

Background: T peak-T end, QT peak/QT ratio and T peak-T end/QT ratio are markers able to test myocardial repolarization homogeneity, their increase has been related to a higher risk of ventricular tachyarrhythmias. These parameters have not yet been studied in left ventricular hypertrophy due to training. Aim of the research was to test the behavior of these variables in the athlete's heart during exercise. Methods: We examined 70 athletes, all males, divided into two groups according to the absence or the presence of a left ventricular mass index over 49 g/m 2.7 and a control group composed of 35 healthy, untrained males. All study participants underwent electrocardiogram at rest, transthoracic echocardiogram, and ergometric test. Repolarization markers (QT, corrected QT, QT dispersion, T peak-T end, QT peak/QT, T peak-T end/QT) were calculated at rest, at peak exercise and during recovery. Results: There was no statistically significant difference among the groups regarding all the parameters studied, except for corrected QT at rest between athletes with left ventricular hypertrophy and control group. The behavior of repolarization markers during exercise was not dissimilar in the three groups. Conclusions: Athlete's heart is not associated to any alteration in ventricular repolarization homogeneity, neither at rest nor during physical activity nor during recovery. Training-induced left ventricular hypertrophy does not affect relationship QT parameters/RR interval. © 2012, Wiley Periodicals, Inc.