Your choice: Hypertrophic obstructive cardiomyopathy
Hypertrophic cardiomyopathy with or without obstruction in an 18-year-old may remain asymptomatic. When symptomatic, dyspnea, anginal chest pain and presyncope or syncope are typical. The disease may be familial, with a family history of sudden death an indicator. The combination of presyncope / syncope and a family history of sudden death are particularly ominous.