RESUMO
INTRODUCTION: The 12-lead electrocardiogram (ECG-12) is a useful tool in the assessment of athletes. The prevalence of normal electrocardiographic findings in elite Brazilian football players (EBFP) of different ethnicities is not well described. PURPOSE: To compare the prevalence of normal ECG-12 findings in Caucasian, Mixed-race (MR), and Afro-Brazilian (AB) EBFP. METHODS: A multicenter cross-sectional descriptive study was conducted with exams performed on EBFP as a pre-participation assessment from February 18, 2002, through October 20, 2022. RESULTS: 4,363 EBFP from 51 professional clubs (from all five regions of Brazil; 15 states, and 21 cities), aged 15-35 years (median: 19 years; IQR: 16-23) were evaluated. 2,027 were Caucasians, 1,324 were MRs, and 1,012 were ABs. In general, we recorded 4,155 ECG-12 with normal variations (95.2%). Positive Sokolow-Lyon criteria for left ventricular hypertrophy was more prevalent in ABs (41.8%) than in Caucasians (33.4%), or MRs (32.7%). The prevalence of early repolarization in ABs (41.5%) was higher than in Caucasians (34.6%), or MRs (35.5%). The PR interval was longer in ABs (157.1 ms) than in Caucasians (151.4 ms), or MRs (153.3 ms), and the first-degree atrioventricular block was more frequent in ABs compared to MRs (4.2% vs. 2.3%, respectively). On the other hand, Caucasians had a higher prevalence of incomplete right bundle branch block (14.2%) than MRs (11.2%), or ABs (9.7%). In our sample, only three EBFP showed second-degree atrioventricular block Mobitz type I (0.07%; one Caucasian and two AB athletes). CONCLUSIONS: This is the first large study to compare the prevalence of ECG-12 findings in EBFP from different ethnic groups. Those of AB origin have a significantly higher prevalence of ECG-12 findings compatible with the athlete's heart than Caucasians and MRs.
