Prevalence of abnormal electrocardiograms in Swiss elite athletes detected with modern screening criteria.

Abstract

Sudden cardiac arrest in athletes is a rare but dramatic event. The value of a routine electrocardiogram (ECG) during preparticipation screening (PPS) remains controversial, partly because of the relatively high number of false positive findings. Our study aimed to evaluate the prevalence of abnormal ECGs in consecutive Swiss elite athletes, overall and with regard to different sports classes, using modern screening criteria. We analysed the 12-lead resting ECGs of high-level elite athletes (age ≥14 years) recorded at the Swiss Olympic Medical Centre Magglingen between 2013 and 2016 during routine PPS. The overall prevalence of abnormal ECGs was evaluated and compared in accordance with the original and revised Seattle criteria. Sports disciplines were categorised according to their static (estimated percentage of maximal voluntary contraction, I-III) and dynamic (estimated percentage of maximal oxygen uptake, A-C) components, and the prevalence of abnormal ECGs compared between sports classes by Fisher's exact test (with alpha set at 0.05). ECGs from 287 consecutive athletes were analysed (64.1% male; 99.7% Caucasian; median age 20.4 ± 4.9 years; median weekly training volume 17.7 ± 7.1 hours). Based on original Seattle criteria, eight (2.8%) ECGs were classified as abnormal: three T-wave inversion (TWI), one Q-wave duration >40 ms, two QRS left axis deviation, two Q-wave amplitude >3 mm. The use of the revised Seattle criteria reduced the number of abnormal ECGs to four (1.4%): three TWI, one Q-wave duration >40 ms. Further cardiological work-up revealed an underlying structural heart disease in only one of these four athletes (inferolateral TWI on ECG), consisting of very localised mid-wall fibrosis suggestive of former myocarditis. There was a significant difference in occurrence of abnormal ECGs between the different sports categories (p = 0.018). All four abnormal ECGs according to the revised Seattle criteria occurred in the high dynamic sport classes (IIC and IIIC); three out of the four were found in the high dynamic high static class (IIIC). In our cohort of high-level elite athletes, the prevalence of abnormal ECGs according to modern screening criteria was very low. All athletes with an abnormal ECG performed high dynamic sports. Less than one percent of our athletes had a new relevant cardiac diagnosis.