Human Parvovirus B19–Associated Myocarditis

To the Editor: 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 . . .