Abstract: Objective To explore etiology and pathogenesis of viral myocarditis(VMC) and dilated cardiomyopathy(DCM).Methods The expression of Coxsackie B virus and adenovirus receptors(CAR) were detected with modified immunohistochemical(IHC) technique in myocardium of left ventricle,right ventricle,interventricular septum,and septal papillary muscle from 28 patients with viral myocarditis,31 patients with dilated cardiomyopathy and 17 control patients(including normal,hypertension heart disease,myocardial infarction and coronary atherosclerotic heart disease).Results The brown staining on the cell membrane of myocardium represents positive result.100%(28 of 28) of VMC patients(IHC surface integral: 4.397 5±0.036 5) and 84%(26 of 31) of DCM patients(4.206 4±0.052 6) had prevalent CAR expression compared to 0%(0 of 19) control patients(0.073 1±0.036 2).There were statistically significant differences between VMC/DCM and control patients(P<0.05).Conclusion The prevalence of CAR expression was significantly higher in VMC and DCM patients(100% and 84% VS 0% in control).In contrast,there was no difference found between VMC and DCM patients.These results suggest that both VMC and DCM involve viral etiology and could share a similar pathogenesis.

Key words: sudden cardiac death, viral myocarditis, dilated cardiomyopathy, coxsackie bvirus-adenovirus receptor, immunohistochemistry