Prevalence of abnormal electrocardiographic findings in a brazilian cohort of young football players: B-pro foot ECG pilot study

Type of funding sources: Foundation. Main funding source(s): Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Hospital de Clínicas de Porto Alegre Research and Event Incentive Fund (FIPE-HCPA)

The 12-lead resting electrocardiogram is a useful tool for diagnosing pathological conditions in athletes. The prevalence of electrocardiographic abnormalities in Brazilian soccer players are unknown.

To describe the prevalence of abnormal electrocardiographic findings in young Brazilian soccer players based on the "2017 International Criteria for Electrocardiographic Interpretation in Athletes".

Continuous variables were displayed as mean and standard deviation or median and interquartile range, while prevalence’s with 95% confidence intervals, and stratified by race. Intra-group differences were estimated by linear models or binomial and multinomial logistic regressions. Type I error was set to set a at 0.05. An additional margin of 0.025 was considered at the discretion of the statistician conditioned to the quality of the model. All analysis were running in Stata version 16.0.0.

2,581 young Brazilian soccer players from 27 clubs (mainly first division), aged 15-35 years (median: 18 years) were evaluated. 1,268 (49.1%) were Caucasians, 796 (30.8%) Mixed-Race (MR) and 517 (20.1%) Afro-Brazilians (AB). T-wave inversion (TWI) in the inferior leads (3.0%), high lateral leads (DI/aVL) (0.6%), V5 (2.3%), V6 (1.8%), and V5-V6 (1.7%) were present. Six Caucasians (0.5%) presented TWI in V1-V4. Prolonged corrected QT interval (QTc) (0.5%), QRS ≥140 ms (0.2%), "pathological" anterior Q waves (0.2%), lateral ST-segment depression (0.07%), premature ventricular contractions (0.5%), Mobitz type II atrioventricular block (0.03%), and a Wolff-Parkinson-White pattern (0.04%) were also observed. There were no athletes with short QTc interval, epsilon waves, profound sinus bradycardia (<30 beats per minute), complete left bundle branch block, third-degree atrioventricular block, or Brugada pattern (1, 2 or 3). Overall, 111/2,581 (4.3%) soccer players had electrocardiographic changes considered to be abnormal (4.4% in Caucasians, 4.5% in MR and 6.4% in AB). There was no difference between the abnormal findings among races, except for the prevalence of TWI in V6, which was higher in AB compared to Caucasians (3.1% versus 1.2%, respectively; P = 0.01).

To the best of our knowledge, this is the first large electrocardiographic cohort of Brazilian young soccer players to be described. In this sample, we evidence a prevalence <5% of abnormal findings according to the "2017 International Criteria for Electrocardiographic Interpretation in Athletes". Additional evaluation in all these cases is indicated.