Pathogenesis of chronic myocarditis in mice infected with coxsackie B3 viruses.

Infection of 300 mice of the Swiss race with Coxsackie B3 viruses gave rise to chronic myocarditis and endocarditis. The virus was cultured from the heart muscle 9 days post infection. Between days 18 and 108 post infection, virtually all mice showed evidence of an active inflammatory process in the myocardium, and in one half there was proliferation of endothelial cells, and infitration and fibrosis in the endocardium. Immunomorphologic studies demonstrated the precence of antiheart antibodies in the blood serum, and Coxsackie B3 antigen and immunoglobulin deposits in the myocardium and endocardium. Highest levels of antivirus antibodies were observed 18 days post infection.