An Experimental Model for Myocarditis and Congestive Heart Failure after Rabbit Coronavirus Infection

In a model for virus-induced myocarditis and congestive heart failure, rabbit coronavirus infec-tion was divided into acute (days 2-5) and subacute (days 6-12) phases on the basis of day of death and pathologic findings. During the acute phase, the principal histologic lesions were degeneration and necrosis of myocytes, myocytolysis, interstitial edema, and hemorrhage. The severity of these changes increased in the subacute phase. Pleural effusion and congestion of the lungs and liver were also present at this time. Myocarditis was detected by day 9 and peaked by day 12. Heart weights and heart weight-to-body weight ratios were increased, and dilation of the right ventricular cavity became prominent early in infection and persisted. In contrast, dilation of the left ventricle occurred late in the subacute stage. Virus was isolated from infected hearts between days 2 and 12. These data suggest that rabbit coronavirus infection progresses to myo-carditis and congestive heart failure. Viruses have long been recognized as important etiologic agents of heart disease in humans and experimental animals [1-3). Epidemiologic evidence suggests that after viral infec-tion, 2%-5 % ofa human population experience some degre