[Dilated cardiomyopathy--heart muscle disease of unknown origin or an autoimmune disease? New aspects of etiology, pathogenesis and clinical practice]

Abstract

Recent evidence suggests that the most common form of idiopathic cardiomyopathy in our altitudes, the dilated cardiomyopathy (DCM), is a post-infectious autoimmune disease which is triggered by virus infections. In animal experiments, the development of the coxsackie virus B3 myocarditis to a congestive cardiac insufficiency resembling the clinical picture of DCM was demonstrated. In mice, species-dependent varying disease courses could be observed, which point to a genetically different behaviour of the animals' immunological reactions, either humoral or T-cell mediated immune reactions being responsible. In comparison with non-DCM patients, patients with DCM and chronic myocarditis exhibit significantly higher coxsackie virus antibody titres. Obviously, also a differently long viral persistency in the cardiac muscle plays a role, as enterovirus-specific RNA was detected in myocardial biopsies from patients with DCM. Along with myocardial fibroses, endomyocardial biopsies in DCM frequently reveal mononuclear cellular infiltrates, which, however, only in 20-25% of the cases may be regarded as chronic persisting myocarditis. The clinical and paraclinical findings in DCM and in the so-called latent cardiomyopathy are presented. In congestive heart failure, the best therapeutic results are achieved by the ACE inhibitors, along with vasodilator agents, digitalis glycosides and diuretics. Ultima ratio is the orthotopic heart transplantation, as it is only this intervention that will be able to improve the primarily bad prognosis decisively. Whether the treatment with immunosuppressive drugs exerts an influence upon the prognosis, has thus far remained an open question.