Experimental coxsackie B viral myocarditis in cynomolgus monkeys.

In 11 of 13 cynomolgus monkeys inoculated with coxsackievirus B3 and/or B4, myocarditis was proved histologically. Myocarditis was evident the first 10 days after inoculation and left chronic sequelae; moderate myocardial cellular hypertrophy with an increase of connective tissue with focal distribution, and some residual inflammatory foci were found 5 months after viral inoculation. Virus was recovered from the heart on the 4th day but not on the 10th day, while serum neutralizing antibody rose significantly over 2 or 3 weeks in most of the inoculated monkeys. Electrocardiographic abnormalities were found in all 11 monkeys in which the myocarditis was proved histologically. These abnormalities were usually transient and were detected most often in the ST-T segment of the right-side chest leads, corresponding to the anatomical distribution of the myocarditis.