Quantitative Assessment Of Left Ventricular Myocardial Function Prior And Post To Percuteaneous Coronary Intervention In Patients With Coronary Heart Disease By Two Dimensional Speckle Tracking Imaging

Objective To investigate the clinical value of identifying early ischemic myocardium and evaluating the effects after percutaneous coronary intervention(PCI) by two dimensional speckle tracking imaging (2DSTI)for patients with coronary heart disease(CHD).Methods Sixty patients without myocardial infarction were divided into 4 groups based on the extent of left anterior descending(LAD)branch stenosis by coronary angiography(CAG).that was normal group (no stenosis),mild group (stenosis<50%),moderate group (stenosis 50%～75%) and severe group (stenosis>75%).High frame rate two-dimensional echocardiography images were recorded from the left ventricular(LV) short-axis views at the levels of mitral annulus,papillary muscle and apex,and the apical four-chamber view,two-chamber view and long-axis view of the LV one week before PCI and three months after PCI respectively.The LV peak systolic longitudinal, radial, circumferential strain ,the basal and apical rotation and the LV torsion of all cases were measured by STI software.Results 1 .Before PCI: The outlines of strain-time curves of normal group were neat and had a higher wave peak,but those of severe stenosis group were disorderly,the peaks of curves in different segments were low and calm;The peak systolic longitudinal strain of different segments of severe stenosis group and some segments of moderate stenosis group were significantly reduced when compared with that of the normal group(P<0.05, P<0.01), that of some segments in severe stenosis group were significantly lower than that in mild stenosis group (P<0.05);however, There was no statistical significant difference in the peak systolic radial strain and circumferential strain of most segments between stenosis groups and normal group(P>0.05); The basal and apical LV rotation and the LV torsion were significantly lower in the severe stenosis group than in the normal group (P<0.05, P<0.01), Compared with the mild stenosis group,the apical LV rotation and the LV torsion were decreased significantly(P<0.05), Compared with moderate stenosis group, only the LV torsion was significantly reduced(P<0.05);The apical LV rotation and the LV torsion in the moderate stenosis group were significantly lower than in the normal group(P<0.05). 2 .After PCI: Three months after treatment,the outlines of strain-time curves of ischemic segments trended to be regular and the peaks elevated markedly;The peak systolic longitudinal strain of most segments in the severe stenosis group increased significantly after three months than that of before PCI (P<0.05); The peak systolic radial strain ,circumferential strain had no significantly improvement in all groups(P>0.05).The LV apical rotation and torsion in the moderate and severe stenosis group were significantly higher than that of before PCI(P<0.05).Conclusion 1.2DSTI could quantitatively evaluate the regional and global function of LV myocardium;2.2DSTI could identify early ischemic myocardium of patients with CHD,and reflect the degree of coronary artery stenosis;3.In a comprehensive analysis of LV longitudinal, radial, circumferential and twist movement of reflecting myocardial function, the longitudinal strain, rotation and torsion would be more sensitive than radial, circumferential strain ; 4.2DSTI provided an economical, convenient, noninvasive method for evaluating the therapeutic efficacy of PCI in patients with CHD.