PURPOSE: To evaluate the prevalence of structural cardiac lesions using 
echocardiography in apparently healthy boys referred for pre-participation 
screening (PPS).
SUBJECTS AND METHODS: 3100 male soccer players were evaluated by 
echocardiography in addition to the standard PPS.
RESULTS: In 56 subjects (1.8%), a structural cardiac lesion with potential 
future complication was detected. Specifically, hypertrophic cardiomyopathy 
(HCM) was found in two boys; bicuspid aortic valve (BAV) in 24; mitral valve 
prolapse in 10 and atrial septal defects (ASDs) in 20. Resting physical 
examination (PE) failed to identify any abnormalities in the majority of the 
subjects. All the boys presented an uncomplicated echocardiography, except two 
boys with HCM, one with BAV associated with aortic dilatation and one with a 
large ASD.
CONCLUSION: Asymptomatic young athletes may have a structural cardiac alteration 
with the potential of present or future haemodynamic and arrhythmic 
consequences. A majority of mild cardiac lesions are difficult to diagnose or 
suspect by the current screening based on medical history, PE and ECG. 
Transthoracic echocardiography significantly improves the diagnostic power of 
screening in the detection of both mild and serious cardiac conditions in the 
athletic population.