Layer-specific strain in assessment of systolic function of segments supplied by coronary artery with varying degrees of stenosis in coronary heart disease patients

Objective To analyze layer-specific strain of left ventricular segments by two-dimensional speckle tracking imaging(2D-STI)in coronary heart disease(CHD)patients,and to evaluate the regional systolic function of left ventricle(LV).Methods Fifty patients were enrolled with suspected CHD.According to the results of selective coronary arteriography(SCA),all patients were divided into coronary heart group(severe stenosis subgroup and mild stenosis subgroup)and control group.All longitudinal strain and circumferential strain of the endo-myocardium,mid-myocardium and epimyoccardium(LSendo,LSmid,LSepi,CSendo,CSmid and CSepi)were attained.The transmural gradient of LS(△LS)and transmural gradient of CS(△CS)were calculated.The statistical analysis was performed.Results With or without corresponding blood-supply coronary artery stenosis,LSendo,LSmid,LSepi,CSendo,CSmid and CSepi showed a gradient decrease.There was no significant difference in △LS among the three groups.Compared with control group,△CS of severe and mild stenosis subgroup decreased significantly(both P0.05).Moreover,compared with control group,LSendo,LSmid,LSepi of severe stenosis subgroup and LSmid,LSepi of mild stenosis subgroup decreased significantly(all P0.05),while there was no significant difference between mild and severe stenosis subgroup in the longitudinal of layer strain(all P0.05).Compared with control group,CSendo,CSmid,CSepi of severe stenosis subgroup decreased significantly(all P0.05),CSendo of mild subgroup decreased significantly(P0.05).There was no significant difference of circumferential layer strain between mild stenosis and severe stenosis group(all P0.05).Conclusion Layer-specific strain of 2D-STI can evaluate the longitudinal and circumferential strain in all left ventricular layers in patients with CHD accurately.Systolic dysfunction is happened through all layers in segments supplied by severe coronary artery stenosis in CHD patients,especially worst in the endocardial myocadium.