The Significance Of Common Biochemical And Molecular Biology Markers For Cardiac Injury And Cardiac Function In The Diagnosis Of Sudden Cardiac Death

Objective: According to the epidemiological survey in China,the incidence of sudden death is 10%,which sudden cardiac death(SCD)accounts for about 50%-60%,ranking first in the incidence of sudden death.Common causes of SCD include acute myocardial ischemia,acute myocardial infarction,cardiomyopathy,myocarditis and so on.Currently in the forensic identification of SCD rely mainly on pathological diagnosis,the lack of demonstration of the correctness of the above diagnostic methods of objective technology.In addition,sudden cardiac death often requires identification of heart disease(morbidity)associated with non-cardiac causes.In recent years,some scholars have proposed using postmortem biochemical detection and quantitative m RNA analysis to detect early myocardial ischemia,necrosis and cardiac dysfunction,providing a possibility for the study of SCD heart disease(pathology),and also provide an objective basis for forensic pathology in the identification objective diagnosis of SCD and other causes of death caused by heart disease(pathological).Some studies have shown that biochemical indicators such as cardiac troponin I(c Tn I),creatine kinase(CK)and N-terminal pro BNP(NT-pro BNP)in the forensic identification of SCD has important ancillary role,and provides an important basis for the identification and diagnosis of SCD.Our previous study also found that hypoxia-inducible factor-1α(HIF-1α),vascular endothelial growth factor(VEGF),brain natriuretic peptide(BNP)have different expression changes in different causes of SCD myocardial tissue.So it is signifiant to looking for objectivity and specificity of biochemical detection indicators and molecular biological indicators to explore the corresponding SCD heart disease(pathological).In order to provide a basis for forensic pathology diagnosis and differential diagnosis of SCD and to explain the mechanism of SCD death due to different causes,we examined the expression of c Tn I,CK-MB and NT-pro BNP in pericardial fluid of SCD deceased by biochemical detection method.q RT-PCR was used to detect the expression of HIF-1α,VEGF-A and BNP m RNA in myocardial tissue in this study.Methods: In this experiment,82 cases(male / female: 71/11)of autopsy cases from2007 to 2017 were selected as the experimental specimens from the forensic center of China Medical University.The selected experimental specimens were both dead time<30 min,post-death elapsed time <72 hours or early post-mortem(within 24 hours)cryopreservation(freezing time <2 weeks)forensic pathological identification of anatomical cases.The cause of death was diagnosed on the basis of a systematic autopsy,histopathology,alcohol test,toxicology test and biochemical test.Cases involving other systemic diseases or injuries unrelated to the cause of death were removed to the experimental group.The expression of c Tn I,CK-MB and NT-pro BNP in pericardial fluid of deceased SCD patients with different causes were detected by biochemical methods.The expression of HIF-1α,VEGF and VEGF in SCD were detected by immunohistochemistry(IHC)and q RT-PCR.Data are expressed as mean ±standard deviation(x ± s).PRISM 6.0 software was used for nonparametric test analysis,p <0.05 was considered statistically significant.Result: 1.The results of biochemical test showed that the cTnI concentration was higher in the myocardial infarction group than the control group,while the concentration of CK-MB and NT-pro BNP in the pericardial fluid were higher in some cases.The concentration of CK-MB were higher in the acute myocardial ischemia group than the control group.The concentration of NT-pro BNP was higher than the control group;The NT-pro BNP concentration was higher in the cardiomyopathy &others than the control group.2.The results of IHC showed that diffuse expression of c Tn I,CK-MB,BNP,HIF-1alpha and VEGF-A was found in IHC staining of all groups,but no positive expression was found in blank control(PBS instead of antibody).There was no significant difference in the expression of c Tn I,CK-MB,BNP,HIF-1α and VEGF-A in the myocardium of SCD patients.3.Real-time PCR results showed that the expression of HIF-1α and VEGF-A m RNA in the myocardial tissue was higher than that of the control group in 68.3% of the deceased IHD patients,and 90% of them died with left ventricular ischemia or global ischemia,while 72.1% of the deceased patients with high BNP m RNA levels expression than the control group,all of them is accompanied by left ventricular failure or heart failure performance,and the expression of BNP m RNA in the myocardial tissue was higher than that of the control group in90.9% of the cardiac dysfunction group,all of them are left heart failure or heart failure performance,and the expression were higher than the control group in 63.6% of the cardiac dysfunction group,all of them were left ventricular ischemia or global ischemia performance..Conclusion: 1.Biochemical indicators of c Tn I,CK-MB and NT-pro BNP plays an important role in the forensic identification of sudden cardiac death.2.Molecular biological indicators of HIF-1α,VEGF-A and BNP combined the biochemical indicators can explain the death mechanism of sudden cardiac death.