Study On Longitudinal And Circumferential Strain Of Ischemic Myocardium

Objective:vestigating the peak systolic longitudinal and circumferential strain of ischemic myocardium at segmental and territorial level.Methods:According to coronary angiograms,83 patients were divided into two groups: the control group (with normal coronary arteries or diameter decrease of <50% in the coronary arteries) and the ischemic group (with diameter decrease of≥70% ). Peak systolic longitudinal and circumferential strain of each left ventricle segment was measured at rest using two-dimensional speckle-tracking echocardiography, and segmental values were averaged to territorial values according to the coronary distribution areas. The difference of strain between two groups was analysed statistically at segmental and territorial level.Results:1. Of 83 patients , 49 had≥70% stenosis (ischemic) and 34 had normal coronary anatomy or < 50% stenosis (control). Of the ischemic group, 1-vessel disease was present in 32, 2-vessel disease in 14, and 3-vessel disease in 3 patients. There was significant left anterior descending artery stenosis in 35, circumflex artery stenosis in 15, and right coronary artery stenosis in 19 patients. Mean stenosis severity by coronary angiography was (77.3±6.9)% in the left anterior descending coronary artery, (76.7±7.0)% in the left circumflex artery, and (77.1±7.3)% in the right coronary artery. 2.①Compared with control group, the longitudinal strain of left ventricle segments in ischemic group were significantly decreased (P<0.05) at segmental level except the segment of basal inferolateral, basal inferior, basal inferoseptal , med inferolateral and med inferior.②As for circumferential strain, except the segment of med anterolateral, med inferolateral and apical lateral, there were no statistically significant (P > 0.05) difference between two groups at segmental level. 3. The 3 territorial longitudinal strain of left ventricle in ischemic group were significantly decreased (P<0.01) compared with control group.②The territorial circumferential strain of left circumflex artery perfusion area was significantly decreased (P<0.05) compared with control group, but two other territorial circumferential strain were not significantly different (P>0.05) between two groups.③The value of territorial strain had less discrete scale than segmental strain.Conclusion:1.The longitudinal strain of ischemic myocardium were significantly decreased both at segmental and territorial level. 2.Except few segment and territory, there were not significant difference between circumferential strain of two groups. 3.Territorial strain is a preferable parameter for evaluating ischemic myocardium because of its containing more information and less numeric discrete scale.