We prospectively evaluated patients (n = 73) with biopsy-proven viral HHV-6 A and B infection
in endomyocardial biopsies (EMBs), followed up by reanalysis of EMBs and left ventricular ejection
fraction (LV-EF) measurements after a median period of 8.8 months (range 4–73 months). Beyond, we
studied HHV-6 prevalence in isolated peripheral blood cells (PBCs) and HHV-6 species in EMBs. HHV-6
species-specific cellular infection sites within the myocardium were identified by immunohistochemistry
(IHC