[The relation of myocarditis to the development of cardiomyopathy]

Dilated cardiomyopathy is a degenerative disease of the myocardium of unknown etiology. Evidence was provided in experiments on mice that it may develop as a late consequence of viral myocarditis. In experiments on mice it was also found that the damaging factor in the pathogenesis of myocarditis may be a reaction of the immune system rather than an infective agent. Research into myocarditis and dilated cardiomyopathy in humans is faced with the difficulty of accurate assessment of the diagnosis; frequently there is no sharp borderline between the two conditions. The possible pathogenetic role of immune reactions is apparent from several publications--the finding of cytotoxic antibodies against myocyte structures, evidence of a reduced function of suppressor T-lymphocytes, impaired function of NK cells. The assembled findings do not provide so far an unequivocal picture of the disease and do not make causal therapy possible.