Prevalence of abnormal electrocardiograms in a large, unselected population undergoing pre-participation cardiovascular screening

AIMS: The implementation of 12-lead ECG in the pre-participation screening of young athletes is still controversial and number of issues are largely debated, including the prevalence and spectrum of ECG abnormalities found in individuals undergoing pre-participation screening. METHODS AND RESULTS: We assessed a large, unselected population of 32,652 subjects [26 050 (80%) males], prospectively examined in 19 clinics associated to Italian Sports Medicine Federation. Most were young amateur athletes, aged 8-78 years (median 17), predominantly students (68%), engaged predominantly in soccer (39%), volleyball or basketball (8% each), athletics (6%), cycling (5%), swimming (4%). The ECG patterns were evaluated according to commonly used clinical criteria. The 12-lead ECG patterns were considered normal in 28 799 of the 32 652 athletes (88.2%) and abnormal in 3853 (11.8%). The most frequent abnormalities included prolonged PR interval, incomplete right bundle branch block (RBBB) and early repolarization pattern (total 2280, 7.0%). Distinct ECG abnormalities included deeply inverted T-waves in > 2 precordial and/or standard leads (751, 2.3%), increased R/S wave voltages suggestive of LV hypertrophy (247, 0.8%), conduction disorders, i.e. RBBB (351, 1.0%), left anterior fascicular block (162, 0.5%), and left bundle branch block (19, 0.1%). Rarely, cardiac pre-excitation pattern (42, 0.1%) and prolonged QTc interval (1, 0.03%) were found. CONCLUSION: In a large, unselected population of young athletes undergoing pre-participation screening, the prevalence of markedly abnormal ECG patterns, suggestive for structural cardiac disease, is low (<5% of the overall population) and should not represent obstacle for implementation of 12-lead ECG in the pre-participation screening program.