Human Parvovirus B19–Associated Myocarditis

Abstract

Viral and postviral myocarditis are the major causes of acute and chronic dilated cardiomyopathy.¹ To gain insight into the pathogenesis of parvovirus B19–associated myocarditis as an endothelial-cell–mediated disease ( Figure 1A ), we measured viral loads in endomyocardial biopsy specimens obtained from 498 patients (341 men and 157 women; mean [±SD] age, 46.93±15.85 years) with myocarditis² or chronic dilated cardiomyopathy who were positive for parvovirus B19 on immunohistologic analysis. A total of 91 noninflamed normal hearts obtained from autopsies served as controls. We found that parvovirus B19 genomes were significantly more likely to be detected in the endomyocardial biopsy specimens of patients with myocarditis (in 322 of 498 patients [64.7%]) and dilated cardiomyopathy (in 176 of 498 patients [35.3%]) than in noninflamed control hearts (in 7 of 91 patients [7.7%]) (P<0.01).