Idiopathic dilated cardiomyopathy is an often fatal cause of heart failure in young adults which is characterized by dilatation of the ventricles, increased myocardial mass, and impairment of systolic function. Dilated cardiomyopathy is more common than hypertrophic and restrictive cardiomyopathy, and the symptoms and physical signs are those of left-sided and eventually right-sided heart failure. Histologic findings in the condition include nonspecific interstitial myocardial fibrosis and myocyte hypertrophy. Despite the large number of systemic or generalized disease processes which have been associated with secondary dilated cardiomyopathy, the majority of cases are idiopathic. Mortality rates from cardiomyopathy have increased dramatically since 1970, and in 1990 over 10,000 deaths annually were attributed to cardiomyopathy in the United States.