Retrospective Analysis Of Sudden Death Cases And The Expression And Significance Of SCN5A Gene In Hypertrophic Cardiomyopathy

Objective: We reviewed and analyzed the cases of sudden death in Qingdao in recent 10 years.This aim of the study was to investigate the expression of SCN5 A protein in cardiomyocytes from patients with cardiomyopathy,and to explore the mechanism of SCN5 A gene in cardiomyopathy such as hypertrophic cardiomyopathy and dilated cardiomyopathy,and discuss the ion channel disease in the process of cardiomyopathy,and further improve the definition and classification of cardiomyopathy.Methods: We chosen autopsy of sudden death in Qingdao Municipal Hospital from January 2006 to December 2016,and we retrospective analysis the cases which conforming to the sudden cardiac death.And we chosen24 cases from all cases: 8 cases died from hypertrophic cardiomyopathy of the HCM group,10 cases died from Dilated cardiomyopathy of the DCM group and 8 cases died from traffic accidents or other unrelated to heart disease of the health group.We observed the staining of HE slices and used immunohistochemical method to compare the expression of SCN5 A,p53,Ki67,Bcl2 and Bcl6 in three groups.We used q RT-PCR to analyze the expression of SCN5 A gene RNA in myocardial tissue.We used SPSS19.0 and the data were expressed by `x±s,and P<0.05 were considered to be statistically significant.Results: 1.Among the 621 cases of sudden death,341 cases were caused by cardiovascular diseases(54.91%),and the most common disease of pulmonary embolism and cardiomyopathy.According to age composition and sex ratio,the group of 31-60 year old age is the most frequent age,and the male is much more than the female.2.HE staining: HCM group visible myocardial fiber hypertrophy,myocardial cell disorder,big and deep staining,abnormal,myocardial interstitial fibrous tissue increased performance;DCM group showed myocardial fiber corrugated,myocardial nuclei,deformity,perinuclear visible lipofuscin deposition;The health group only visible minority myocardial hypertrophy,vascular dilatation and congestion part etc.SCN5 A immunohistochemical results: HCM group of SCN5 A IOD(221006±45239)higher than that of normal group(12643±3251),P=0.034(P<0.05),the difference was statistically significant,but there is no difference between with DCM's IOD(221006±45239),P>0.05,no statistical significance.The immunohistochemical results of p53,Ki67,Bcl2 and Bcl6 showed that in the HCM group,the IOD of the four groups were negative compared with those in DCM group and healthy group,and the difference was not statistically significant.PT-PCR results: In group of HCM and DCM,the expression of RNA in the SCN5 A gene were significantly higher than that in healthy group,P=0.0023(P<0.05),the difference was statistically significant.Further analysis showed that there was no correlation between SCN5 A and sex,age and myocardial thickness.Conclusion: Sudden death is still one of the most common causes in forensic pathology.And the main reason for cardiac sudden death is coronary heart disease,pulmonary embolism and cardiomyopathy.Therefore,the in-depth study of this disease has great practical value.In the study of cardiomyopathy,the over-expression of SCN5 A gene protein may lead to HCM.It is further clear that SCN5 A plays an important role in the development of HCM and DCM.We should include ion-channel cardiomyopathy in the category of cardiomyopathy.Regular HE staining section and p53,Ki67,Bcl2 and Bcl6 are lack of specificity in the diagnosis of cardiomyopathy and they cannot be used as a diagnostic indicator.