A mouse model of dilated-type cardiomyopathy due to coxsackievirus B3.

Myocardial scarring was induced in 111 mice (group 3) inoculated at 14 days of age with coxsackievirus B3 and forced to swim for 30 min daily during the initial nine days of infection. The animals were observed until age 15 months. Control animals included mice infected but not forced to swim (group 2), neither infected nor forced to swim (group 1), and not infected but forced to swim (group 4). The cumulative mortality was 45% among mice in group 3 but was significantly lower in the control animals. At 15 months, mice in group 3 showed heavy deposits of calcium in the injured myocardium, atrial hypertrophy with thrombi, and myocardial fiber disintegration with replacement by fibrous scar. Mononuclear infiltration was no longer present. Pathologic changes were concentrated in the left ventricle, interventricular septum, and atrioventricular junction. Titers of type-specific neutralizing antibodies had declined to one-fifth the level present at one month. These findings represent a model of dilated-type cardiomyopathy.