ELECTROCARDIOGRAPHIC FINDINGS OF REPOLARIZATION IN ATHLETIC STUDENTS AND CONTROL SUBJECTS

We have investigated resting electrocardiograms in 1,299 athletic stud ents and 151 sedentary control subjects. ST elevations were more frequ ent and pronounced in athletes compared to controls, whereas there was no difference in ST depressions. Athletes with ST elevation above 2 m m were characterized by lower heart rate, increased PQ duration, incre ased indices of left, right and septal hypertrophy and T wave amplitud e. Negative T waves in 3 of 6 precordial leads, V-3-6, were found in 1 .5% of athletes and 0.7% of controls, and in V-5-6 in 0.4% of athletes and none of controls, the differences not being significant. Athletes had significantly more often a T wave axis between +30 and -180 degre es and less often a frontal T wave axis between +30 and +180 degrees. The mean QRS-T angle was significantly greater in athletes, and U wave s were more prominent. Analyzing athletes with QT(c) below and above 0 .430 s, we found an increased heart rate, RS duration, ST depression a nd a more pronounced left QRS axis in the group with QT(c) above 0.430 s. There was a positive correlation between QT(c) and heart rate whic h indicates that the use of Bazett's formula leads to an underestimati on of QT(c) at lower heart rates and to an overestimation at higher he art rates. Bazett's formula does not provide an adequate correction fo r heart rate and should be used with caution. Our finding of a prolong ed QT(c) in athletes compared to control subjects in spite of lower he art rate in the athletic group demonstrates that a real QT(c) prolonga tion exists in athletes.