The Feature Of Heart Rate Variability In Patients With Type 2 Diabetes Mellitus And Coronary Heart Disease And The Relationship Between Heart Rate Variability And Cardiac Structure Function Indexes

1 Background and Objectives Heart rate variability can reflect the state of autonomic nervous function,its decrease can be a independent risk factor for arrhythmia events and death after myocardial infarction.This situation indicates poor prognosis include congestive heart failure,diabetes neurosis and so on.Through analysing four groups(type 2 diabetes mellitus group,Coronary heart disease(CHD)group,type 2 diabetes mellitus and coronary heart disease group and normal control group)’ indexes include general clinical data,blood biochemical indicators,heart rate variability index and cardiac structure function index to observe the correlation of type 2 diabetes,the influence of CHD on heart rate variability,index of correlation of heart rate variability and cardiac structure function index.2 Object and MethodsTo reach the research object,choose the complete data of 128 patients from The Second Affiliated Hospital of Zhengzhou University between September 2014 and September 2016.They are divided into the following four groups:control group,T2 DM group,CHD group,T2 DM with CHD group.The number of patients in coronary group and T2 DM with CHD group is 65.Based on the degree of coronary artery stenosis,the 65 patients are divided into two groups: completely blocking group(at least 1 complete occlusion of coronary artery)and the lesion group(at least one branch of coronary artery lesions,but not completely blocked).According to how many branch of coronary artery lesion,divided into 1,2,3.According to the presence of collateral circulation,divide into yes and no.According to their lesion position,divided into the left anterior descending branch,left circumflex branch and right coronary artery.Collect general clinical data.Record biochemical examination data including glycated hemoglobin(Hb Alc)(%),serum triglyceride(TG),serum levels of total cholesterol(TC),serum high-density lipoprotein cholesterol(HDL-C)and so on.Record coronary angiography results include the name of lesion blood vessel,number of branch,degree of stenosis(%)and if there were any collateral circulation.Record heart rate variability index include SDNN,SDANN,ASDNN,r MSSD,and p NN50.Using SPSS17.0 to analyze type 2 diabetes,coronary heart disease,type 2 diabetes mellitus with coronary heart disease(CHD),the changes of heart rate variability index in patients with type 2 diabetes mellitus and coronary heart disease,the relationship between coronary lesions and heart rate variability index,the correlation of heart rate variability index and cardiac structure function index,etc.3 Research Results 3.1 General clinical data comparison For the control group,the T2 DM group,CHD group and T2 DM with CHD group,there is no significant difference between the four groups of age and gender(p>0.05).3.2 Comparison of blood biochemical indexes The difference of each index include Hb Alc,TC,TG,HDL,LDL has statistical significance(p<0.05)by comparing the four groups.T2 DM group’s indexes of Hb Alc,TC,TG and LDL are higher than the control group,its difference has statistical significance(p<0.05),but its index of HDL is lower than the control group and the difference has no statistical significance(p>0.05).T2 DM with CHD group has higher indexes of Hb Alc,TC,TG and lower index HDL than the control group and the difference have statistical significance(p<0.05),index of LDL has no statistical significance(p>0.05).CHD group’s HDL is lower than the control group,and the difference has statistical significance(p<0.05),but the higher indexes of Hb A1C、TC、TG、LDL have no statistical significance(p>0.05).CHD group has lower indexes of HBAlc,TC and TG than T2 DM group and the difference has statistical significance(p<0.05),but the indexes of HDL and LDL has no statistical significance(p>0.05).T2 DM with CHD group’s indexes of HDL and LDL is lower than T2 DM group and the difference have statistical significance(p<0.05),its indexes of Hb Alc and TG is higher,TC is lower,and their difference have no statistical significance(p>0.05).Compared to CHD group,T2 DM with CHD group has higher indexes of Hb Alc and TG and the difference have statistical significance(p<0.05),but its higher indexes of TC and HDL and lower index of LDL have no statistical significance(p>0.05).3.3 Comparison of four groups of heart rate variability in time domain To analyze HRV’s index of 24 h SDNN,generally the normal value is ≥100ms,<100ms is modestly reduced value,<50ms is obviously decreased value.There are 3,10,11,18 cases have decreased HRV in control group,T2 DM group,CHD group,T2 DM with CHD group respectively.The incidence is 9.68%、31.25%、34.38%、54.55% respectively.Comparison between four groups,T2 DM with CHD group has the highest HRV decrease incidence.3.4 Circadian rhythm analysis of T2 DM with CHD group For Type 2 diabetes mellitus with coronary heart disease group,compare waking state with sleep state,indexes of heart rate variability,SDNN,SDANN,ASDNN,r MSSD and p NN50 have no significant differences(P>0.05).But for healthy control group,indexes under sleep state are significantly higher than waking state(P<0.05).3.5 Change of the cardiac structure function and correlation analysis of heart rate variability LVEF,E/A: type 2 diabetes mellitus with coronary heart disease group is lower than T2 DM group and coronary heart disease group.LVEDD,LA: type 2 diabetes mellitus with coronary heart disease group is higher than T2 DM group and coronary heart disease group(P<0.05).3.6 The correlation analysis between cardiac structure function indexes and heart rate variability Correlation analysis of the index of heart rate variability and the index of cardiac structure function: SDNN is negatively correlated with LA and LVEDD,but positively correlated with LVEF,E/A.SDANN is negatively correlated with LVEDD,but positively related with LVEF and E/A.ASDNN is positively correlated with LVEF.r MSSD is positively related with LVEF and E/A(P<0.05).3.7 Comparison of the results of coronary angiography Compared to CHD group,T2 DM with CHD group has significant increase in the ratio of vascular lesions and serious vascular stenosis.The differences have statistical significant(p<0.05).3.8 The relationship between type of coronary artery lesions and heart rate variability Comparing the lesion group with completely blocking group,SDNN,SDANN and ASDNN decrease obviously(P<0.05),but r MSSD and ASDNN do not(P>0.05).With the increase of coronary artery lesion counts,SDNN and SDANN have gradually decline,but the decline is obviously(P<0.05)only when the count is three.ASDNN decline obviously(P<0.05)when the lesion count is two.There is no statistically significant difference comparing r MSSD group and p NN50 group(P>0.05).Presence of coronary collateral circulation or not forms subgroups comparison,and the heart rate variability has no obvious change.LAD and LCX lesion,SDNN and SDANN decline obviously(P<0.05),but the other indexes have no obviously decrease(P>0.05).4 Conclusion 4.1 The type 2 diabetes mellitus with coronary heart disease group has the most serious damage in autonomic nerve,and its circadian rhythm of heart rate variation vanishes.4.2 HRV measurement is not only valuble but also noninvasive when used in the evaluation of coronary heart disease state.If HRV of coronary heart disease(CHD)patients significantly reduces,it is probable that their narrowed coronary arteries are heavy,Lesions are in the left coronary artery and the lesions are wide.4.3 HRV can reflect the severity of the cardiac remodeling and cardiac function damage.