Quantitative Evaluation Of Stratified Myocardial Systolic Function In Patients With Coronary Artery Disease By Speckle Tracking Imaging

Objectives The three-layer systolic function of ischemic myocardium in patients with coronary artery disease(CAD)was evaluated quantitatively by two-dimensional speckle tracking imaging(2D-STI)technique,which provided a more accurate,simple and objective basis for the early diagnosis of CAD.Methods From September 2017 to September 2018,this study selected patients with suspected CAD were admitted to the Department of Cardiovascular Medicine,affiliated Hospital of North China University of Technology,due to paroxysmal chest pain.Determination of ischemic myocardial segments according to the results of coronary angiography(CAG),CAG showed no stenosis in the normal control group(n=702),the corresponding myocardial segments with 0 to 50% of coronary artery stenosis were group A(n=540),the corresponding myocardial segments with 50% to 75% of coronary artery stenosis were group B(n=486),and the corresponding myocardial segments with 75% to 99% coronary artery stenosis were group C(n=518).The longitudinal,circumferential and radial whole layer strain parameters(Gls,Gcs,Grs,ls,cs,rs)and longitudinal,circumferential layered strain parameters(Endo-Gls,Mid-Gls,Epi-Gls,Endo-Gcs,MidGcs,Epi-Gcs,Endo-cs,Mid-cs,Epi-cs,Endo-ls,Mid-ls,Epi-ls)of the whole and each cross section horizontal are obtained by software analysis.The ratio of endocardium to epicardium(Endo/Epi),was calculated as the transmural gradient between endocardium and epicardium.Establish the database and use SPSS 22.0 for statistical analysis.All normality measurement data used by mean±standard deviation(),and one-way ANOVA was used for all groups and intra-group comparisons.The counting data were expressed as frequency or rate,pearson card-square test was used to compare the data among each group.The strain parameters in one-way ANOVA were used as test variables,and the results of coronary angiography were used as state variables.The ROC curves of each strain parameter were drawn to predict moderate and severe coronary artery stenosis.The difference was statistically significant(P<0.05).Results 1 Comparison of the whole layer strain parameters of each group,compared with the control group,the parameters of Gls,Basal-ls,Mid-ls,Apex-ls in group C were lower(P<0.05),there was no significant difference in parameters Gcs,Basal-cs,Mid-cs,Apex-cs and Grs,Basal-rs,Mid-rs,Apex-rs among groups(P>0.05).2 Comparison of stratified strain parameters in each group,1)comparison of longitudinal delamination strain parameters,(1)in the strain parameters of global longitudinal delamination,compared with the control group,Endo-Gls and Endo/Epi Gls in group B decreased significantly(P<0.05),Endo-Gls,Mid-Gls,Epi-Gls and Endo/Epi Gls in group C decreased significantly(P<0.05),and the Endo-Gls,Mid-Gls,Epi-Gls of group C was lower than that of group A and B(P<0.05).(2)Comparison of longitudinal delamination strain parameters of each cross section horizontal,compared with the control group,the Endo-ls of the basal segment,the Endo-ls and Endo/Epi ls of the middle segment and the Endo/Epi ls of the apex segment in group B were significantly lower(P<0.05).In group C,the Endo-ls,Mid-ls Endo/Epi ls in basal segment levels,the Endo-ls,Mid-ls,Endo/Epi ls in the middle segment levels and Endo-ls,Mid-ls,Epi-ls in apex segment levels in ischemic segment were lower than control group(P<0.05).(3)Comparison among three layers of myocardium at the global and cross-sectional levels in the control group,EndoGls>Mid-Gls>Epi-Gls,Endo-ls>Mid-ls>Epi-ls,the differences are statistically significant (P<0.05).The results indicate that there is a gradient difference in longitudinal strain between three layers of myocardium in normal adults.Comparison among three layers of myocardium in stenosis group,there was no significant difference among Endo-ls,Mid-ls and Epi-ls in group B and group C at basal level(P>0.05),and there was no significant difference among Endo-ls,Mid-ls and Epi-ls in group B and group C at middle level(P>0.05).It is suggested that the difference of longitudinal strain gradient between three layers of myocardium in partial ischemic segment disappears in moderate and severe coronary artery stenosis.2)Comparison of circumferential delamination strain parameters,(1)in the strain parameters of global circumferential delamination,the Endo-Gcs and Gcs-Endo/Epi in group C were lower than those in control group,group A and group B(P<0.05).(2)In the strain parameters of circumferential delamination of each cross section horizontal,compared with the control group,the Endo-cs of myocardial basal segment of ischemic segment in group C was lower(P<0.05),the parameters Endo-cs and Endo/Epi cs of middle segment and apex segment in group C were lower(P<0.05).(3)Comparison among three layers of myocardium at the global and cross-sectional levels in each group,Endo-Gcs>Mid-Gcs>Epi-Gcs,Endo-cs>Midcs>Epi-cs,the differences are statistically significant(P<0.05).The results showed that there was a gradient difference in the circumferential strain between the three layers of myocardium in normal adults.There was no significant difference between Mid-cs and Epi-cs in stenosis group C at apical segment level(P>0.05).It is suggested that the difference of circumferential strain gradient between three layers of myocardium in partial ischemic segment disappears during severe coronary artery stenosis.3 When the ROC curve was used to predict severe coronary stenosis,it was found that the area under the curve for predicting severe coronary stenosis by parameter Endo-ls was the largest at each cross-sectional level,and the diagnostic efficiency was the best.Conclusions The systolic function of different layers myocardium and segments of coronary artery stenosis patients with normal LVEF can be quantitatively evaluated by 2D-STI technique,it can provide objective basis for myocardial localization of ischemic segment and assessment of coronary artery stenosis degree in coronary heart disease.Figure 7;Table 18;Reference 141...