[Epidemiology-etiology of Dilated Cardiomyopathy]

Among the cardiomyopathies,--dilated cardiomyopathy (dcm), hypertrophic cardiomyopathy, restrictive cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy--, dcm is the most frequent entity. Its prevalence in the United States amounts to 36 cases per 100,000 inhabitants, men being almost 3-fold more involved than women. The etiology of dcm is very heterogenous; 50% of the cases are due to idiopathic dcm whereas the other half comprises a broad spectrum of various etiologies such as myocarditis, ischemic heart disease, peripartal cardiomyopathy, hypertension, HIV infection, toxic cardiomyopathy and others. In 20 to 30% of the cases of idiopathic dcm a genetic transmission of the disease has been found. Another 20 to 30% of idiopathic dcm are associated with inflammatory and immunological phenomena. Infectious myocarditis with enteroviruses, especially with coxsackie-virus type B has been suggested to be an important trigger for an immune-mediated dcm. In both, familiar dcm and infection with coxsackie-virus B, an impairment of constituents of the myocardial cytoskeleton has been shown. This is regarded as a possible pathogenetic mechanism in the development of dcm.