Abstract: Objective To investigate the changes of collagen fibers and the expression of osteopontin in the left ventricle in cases of hypertrophic cardiomyopathy（HCM）, along with the significance of their potential forensic application. Methods Fifteen cases of HCM, 15 cases of coronary heart disease with cardiac hypertrophy and 20 cases of traffic accidents were selected as HCM group, coronary heart disease group and control group, respectively. Collagen volume fraction and osteopontin expression were observed and compared by HE staining, Masson trichrome staining and immunohistochemistry methods. Imaging and statistical methods were used for quantitative analysis. Results Collagen volume fraction in left ventricle of HCM and coronary heart disease were significantly higher than that in the control group（P<0.05）, which was not significantly different between the HCM group and the coronary heart disease group. The integral light density value of osteopontin in left ventricular cardiomyocytes of the HCM group and the coronary heart disease group were significantly higher than that of the control group（P<0.05）, and the value of the HCM group was also significantly higher than that of coronary heart disease group（P<0.05）. Conclusion The increased contents of collagen fibers and the overexpression of osteopontin may play an important role in myocardial fibrosis, and they can be used as markers in aid of diagnosing sudden death due to HCM.

Key words: forensic pathology, cardiomyopathy, hypertrophic, fibrosis, osteopontin