An Experimental Model for Dilated Cardiomyopathy after Rabbit Coronavirus Infection

Alexander, Lorraine K.; Small, J. David; Edwards, Suzanne; Baric, Ralph S.

A rabbit model for coronavirus-induced dilated cardiomyopathy is described. Acute rabbit coronavirus infection results in virus-induced myocarditis and congestive heart failure. Of the survivors of rabbit coronavirus infection, 41% had increased heart weight and heart weight-to-body weight ratios, biventricular dilation, myocyte hypertrophy, myocardial fibrosis, and myocarditis consistent with the development of dilated cardiomyopathy. These changes were also seen in the remaining 59% of the survivors, except that the degree of myocyte hypertrophy was reduced and only right ventricular dilation was present. In most survivors, myocarditis was usually mild (1–5 foci/transverse section), but in some cases it was severe (>20 foci/transverse section). Interstitial and replacement fibrosis was more pronounced in the papillary muscles. These data suggest that rabbit coronavirus infection may progress to dilated cardiomyopathy.