Research on cardiomyopathy in Japan.

Many experimental and clinical studies have been performed in Japan, since the Idiopathic Cardiomyopathy Research Committee sponsored by the Ministry of Health and Welfare of Japan was organized in 1974. Much interest has been focused on myocarditis as a possible pathogenesis of dilated cardiomyopathy and extensive experimental studies have been performed as well as histopathologic assessment at autopsy or biopsy. In the clinical field, suspected cases of myocarditis are not uncommon, but determination of etiological viruses is quite difficult in most patients except at the acute stage. Therefore, endomyocardial biopsy has been recently introduced in more than 13 institutes in Japan in an effort to obtain more accurate diagnosis. In 1983, the Idiopathic Cardiomyopathy Research Committee performed a study on the prognosis of cardiomyopathy in 1255 patients (786 hypertrophic and 469 dilated). The prognosis of dilated cardiomyopathy was poor, with a 5-year survival rate of only 54.3%. This figure contrasted with the better prognosis in those with hypertrophic cardiomyopathy (92%).