Abstract: Objective In order to improve accuracy and reliability of forensic diagnosis of sudden cardiac death, pathogenesis and relationship between the viral myocarditis（VMC） and dilated cardiomyopathy（DCM） were investigated. Methods Improved immunohistochemical technique was used to detect the expression of the CAR in myocardium samples， including 22 deceased with VMC, 20 deceased with DCM and 16 control deceased. Results The brown staining on the cell membrane of myocardium showed positive result. There was a prominent CAR expression in VMC group and DCM group , which were statistically significant difference compared with control group（P<0.05）. Conclusion The CAR expression showed significantly higher in VMC and DCM groups. The viral infection can result in myocardial necrosis and impaired cardiac functions. These abnormalities can trigger a cascade of events that contributed to the progress of VMC to DCM.

Key words: forensic pathology, death, sudden, cardiac, cardiomyopathy, dilated, viral myocarditis, coxsackie-adenovirus receptor