Analysis of formalin-fixed and frozen myocardial autopsy samples for viral genome in childhood myocarditis and dilated cardiomyopathy with endocardial fibroelastosis using polymerase chain reaction (PCR)

Viral infection of the myocardium is implicated in the pathogenesis of myocarditis and dilated cardiomyopathy (DCM). Enteroviruses have been considered the most common viral etiologic agents, based on peripheral culture and serologic methods. Recently, polymerase chain reaction (PCR) has been shown to be useful in the detection of viral genomes from various infected organs and body fluids. In this study, myocardial samples from autopsy specimens (formalin fixed and fresh frozen) were examined for enteroviral and DNA viral (adenovirus, herpes simplex virus [HSV], and cytomegalovirus (CMV]) genome by PCR. The specimens studied were from 58 patients with myocarditis, 28 patients with DCM and endocardial fibroelastosis [EFE], and 22 controls. Viral genome was detectable in 34 of the 58 (59%) autopsy-proven myocarditis samples (18 adenovirus, 12 enterovirus, 2 CMV, 2 HSV) and 6 of the 28 samples from patients with DCM and EFE (6 adenovirus). We conclude that PCR is effective in the rapid amplification of virus from frozen and formalin-fixed myocardial samples and that adenovirus is an important etiologic agent in viral myocarditis as well as DCM with EFE.