QT dispersion in athletic left ventricular hypertrophy,

Objective To assess whether physiologic left ventricular hypertrophy as a result of physical training is associated with an increased QT length or dispersion. Methods Thirty-three subjects were assessed. These consisted of a group of international endurance athletes (including 8 rowers, 2 cyclists, and 1 triathlete), a group of 12 professional soccer players, and a further group of 10 control subjects. Each underwent 2-dimensional echocardiography and 12-lead electrocardiographic examination. Results Left ventricular mass index was considerably greater in both the endurance athlete (163.3 ± 14.4 g/m2; P < .01) and soccer player groups (144.2 ± 5.5 g/m 2; P < .05) compared with the controls (109.2 ± 6.3 g/m2). In spite of these large differences in cardiac structure there were no significant differences in QT parameters between the groups (QT dispersion 56.9 ± 5.5, 68.5 ± 9.5, and 67.2 ± 12.6 ms; QTc dispersion 61.4 ± 9.2, 69.4 ± 13.3, and 54.2 ± 6.5 ms; maximum QT 402 ± 10.3, 404 ± 9.6, and 392 ± 14.0 ms; and maximum QTc 404 ± 7.0, 413 ± 9.3, and 399 ± 9.9 ms among endurance athletes, soccer players, and controls, respectively). Conclusion Left ventricular hypertrophy occurring as a consequence of athletic training does not appear to be associated with a major increase in QT length or QT dispersion. (Am Heart J 1999;137:678-81.)