Myocarditis causes distinctive histological changes of the myocardium
and is most commonly caused by enterovirus infection. Enterovirus RNA
has been detected in tissue samples obtained from patients with myocar
ditis by endomyocardial biopsy. Similar findings in dilated cardiomyop
athy support the hypothesis that it results from myocarditis in some c
ases and that enterovirus infection plays a pathogenetic role in the d
isease process.