Viral Myocarditis: From Experimental Models to Diagnosis in Patients

Abstract

Infectious agents, and especially viruses, can induce severe forms of acute and chronic lymphocytic myocarditis which may progress to heart failure. The diagnosis of infectious myocarditis in endomyocardial biopsies (EMB) is guided by the detection of viral RNA and DNA using molecular tools such as quantitative (RT-) polymerase chain reaction and in situ hybridization in association with acute and chronic cardiac inflammation. Enteroviruses, parvovirus B19 (B19V), and herpesviruses, i.e., Epstein–Barr virus (EBV), human herpesvirus-6 (HHV6), are most often detected in EMB of patients with myocarditis and dilated cardiomyopathy. Meanwhile it is known that the outcome and course of myocarditis are influenced by genetic host factors as well as by the viral pathogenicity which considerably differs in the various infections. A considerable portion of our knowledge about the etiopathogenetic mechanisms in viral heart disease is derived from animal studies. By investigation of immunocompetent and gene-targeted mice valuable new insights into host and virus factors relevant for the control of cardiac viral infection and inflammation were gained which are reviewed in this paper.