Keshan disease-an endemic cardiomyopathy in China.

Keshan disease, an endemic cardiomyopathy in China, was prevalent in rural areas located in a long belt region where the selenium content was low in foods. Intervention studies with well controlled subjects revealed a prophylactic effect of sodium selenite. Multifocal necrosis and fibrous replacement of the myocardium characterized the histopathological features and myocytolysis was present in most cases. Ultrastructural observations on twelve postmortem cases revealed remarkable changes in many organelles of which mitochondria appeared to be most important in the development of myocardial lesions. Three kinds of specific granules, which have not been found in other reports on cardiomyopathies, were represented and other factors which might also contribute to the aetiology are discussed.