Background: Coxsackievirus is a member of the picornavirus family that can infect the heart and induce acute myocarditis. It may also contribute to some forms of idiopathic dilated cardiomyopathy. In the present study, we evaluated the direct cytopathic effect of coxsackievirus B3 (CVB3) infection in cardiac myocytes, and the molecular mechanisms responsible for the effect. Methods and Results: Immunofluorescent staining with anti-CVB3 and anti-myomesin antibodies showed that CVB3 infection of neonatal rat ventricular myocytes disrupts the myofilament architecture. The presence of internucleosomal cleavage of DNA and chromatin condensation in the infected cells indicates that CVB3 can induce markers of apoptosis in infected cardiac myocytes. In addition, we demonstrate that cardiotrophin-1 (CT-1) that is expressed at high levels in the heart is able to promote survival and inhibit apoptosis of CVB3 infected cultured myocytes. Other cytokines/growth factors such as IL-6, TGF-beta had no significant effect on myocyte survival following infection with CVB3. Conclusion: In conclusion, these data demonstrate that CVB3 can infect neonatal rat ventricular myocytes and induces a direct cytopathic effect by activating apoptosis in the cells. This cytopathic effect is inhibited by CT-1 suggesting that CT-1 may have an important autocrine or paracrine effect on the pathogenesis of viral heart disease.