Fatal parvovirus B19-associated myocarditis clinically mimicking ischemic heart disease: An endothelial cell-mediated disease

We report the case of a 34-year-old female patient who died 4 days after hospital admission of acute heart failure clinically mimicking ischemic heart disease. Microscopic examination of the heart showed severe myocarditis. Polymerase chain reaction (PCR), including quantitative real-time PCR, disclosed exclusively parvovirus B19 (PVB19), with a high viral load of 4.3x10(5) PVB19 viral genome equivalents per mug myocardial nucleic acid. Radioactive in situ hybridization detected viral genomes in endothelial cells (ECs) predominantly in the venular compartment and (to a lesser degree) in small arteries and arterioles of the heart, but not in cardiac myocytes or other tissue components. Concomitant with EC infection, marked expression of the adhesion molecule E-selectin was noted, accompanied by margination, adherence, penetration, and perivascular infiltration of T lymphocytes. We speculate that, due to the high viral load in cardiac ECs, PVB19 infection of endothelial cells was sufficient to induce impaired coronary microcirculation with secondary cardiac myocyte necrosis.