Electrocardiographic abnormalities in Syrian golden hamsters with coxsackievirus B1 myocarditis

Serial electrocardiograms of acute viral myocarditis were recorded from Syrian golden hamsters inoculated with Coxsackievirus B1 (CVB1). Various electrocardiographic abnormalities similar to those reported in human viral myocarditis were observed. The reciprocal ST displacement and/or T wave flattening were most frequently found, and were detected in 80% of the animals. Occasionally, other abnormalities such as atrioventricular (AV) block, left bundle branch block (LBBB) pattern or extrasystoles were recorded. A histopathological examination disclosed the most prominent lesions of myocarditis in the endocardial third of the myocardium, particularly in the interventricular septum. These lesions were more widespread in the left ventricule than in the right. A close correlation between the electrocardiographic manifestations and distribution of the lesions in the myocardium was observed. Since electrocardiography is widely used in clinical medicine, its application to experimental viral myocarditis will promote the study of viral myocarditis and the analysis of myocardial fibrosis as its sequelae.