Hypertrophic cardiomyopathy (HCM) is the main cause of sudden unexpected death 
in the young and especially in young athletes with an incidence up to 2.3 per 
100,000 athletes and year. Risk stratification models including patient history 
(syncope, familial risk of sudden death) and findings in noninvasive tests 
(nonsustained ventricular tachycardia, abnormal blood pressure response during 
exercise, maximum left ventricular wall thickness > or = 30 mm) have been 
developed in order to estimate the risk of individual patients. 
Echocardiographic parameters are helpful in distinguishing HCM from athlete's 
heart. Definitive diagnosis of HCM implicates disqualification from competitive 
sports resulting in a significant reduction of sudden cardiac death due to HCM 
during sports competition. This positive development should lead to a widespread 
preparticipation screening of athletes including historical, clinical, and 
electrocardiographic examination. At least in borderline findings and 
symptomatic athletes, an additional echocardiogram should be performed in order 
to minimize or better exclude the risk of sudden cardiac death.