RESUMO
BACKGROUND: Sports activity has become extremely popular among amateurs. Electrocardiography is a useful tool in screening for cardiac pathologies in athletes; however, there is little data on electrocardiographic abnormalities in the group of amateur athletes. OBJECTIVES: The aim of this study was to analyze the abnormalities in resting and exercise electrocardiograms (ECGs) in a group of amateur athletes, and try to determine whether the criteria applied for the general population or for athletes' ECGs should be implemented in this group. MATERIAL AND METHODS: In 40 amateur male marathon runners, 3 consecutive 12-lead ECGs were performed: 2-3 weeks before (stage 1), just after the run (stage 2) and 2-3 weeks after the marathon (stage 3). Resting (stage 1) and exercise (stage 2) ECGs were analyzed following the refined criteria for the assessment of athlete's ECG (changes classified as training-related, borderline or training-unrelated). RESULTS: In resting ECGs, at least 1 abnormality was found in 92.5% of the subjects and the most common was sinus bradycardia (62.5%). In post-exercise ECGs, at least 1 abnormality was present in 77.5% of the subjects and the most common was right atrium enlargement (RAE) (42.5%). Training-related ECG variants were more frequent at rest (82.5% vs 42.5%; p = 0.0008), while borderline variants - after the run (22.5% vs 57.5%; p = 0.0004). Training-unrelated abnormalities were found in 15% and 10% of the subjects, respectively (p-value - nonsignificant), and the most common was T-wave inversion. CONCLUSIONS: Even if the refined criteria rather than the criteria used for normal sedentary population were applied, the vast majority of amateur runners showed at least 1 abnormality in resting ECGs, which were mainly training-related variants. However, at rest, in 15% of the subjects, pathologic training-unrelated abnormalities were found. The most frequent post-exercise abnormality was right atrial enlargement. General electrocardiographic screening in amateur athletes should be taken into consideration.