Left Ventricular Function Before And After Coronary Artery Bypass Grafting As Assessed By Speckle Tracking Imaging In Patients With Coronary Heart Disease

ObjectiveSpeckle Tracking Imaging (STI) can evaluate the myocardial function more quickly,with the characteristic of sensitivity, noninvasive and no angle dependence. Coronaryatherosclerotic heart disease (CHD) is ischemia and hypoxia of heart muscle because ofstenosis or occlusion of coronary artery caused by atherosclerosis or functional change(spasm). Coronary artery bypass grafting (CABG) is an effective coronaryrevascularization method, which can reconstruct blood supply and improve oxygensupply of ischemia of heart muscle. It plays an important clinical role in the diagnosis,treatment and judgment of prognosis that how to evaluate LV function. The presentstudy was to assess left ventricular（LV）movement between CHD group and normalgroup using STI. The purpose of this study were:1. To evaluate the difference ofregional and global LV function between patients with CHD and normal people.2. Toevaluate the difference of regional and global LV function between patients with CHDbefore and after CABG.3. To study the correlation between left ventricular ejectionfraction(LVEF) and average global strain(GLS-Avg). MethodsThirty normal adults were included as the control group and thirty-two adults with CHDas CHD group. Transthoracic echocardiography (TTE) was performed in CHD grouppreoperative and3months after CABG. The two-dimensional data were obtained inapical4-chamble,2-chamble and long axis view. Simpson method was used to measureLVEF. Q-lab software was used to measure peak systolic longitudinal strain (SLs),systolic longitudinal strain rate (SrLs), early diastolic longitudinal strain rate (SrLe),global longitudinal systolic strain (GLS) and average global strain(GLS-Avg).Results1．There were no significant differences in age, sex and HR (P>0.05) between controlgroup and CHD group. Compared with preoperative, LVEDd, LVEDv, LVESv at threemonths after CABG were significant decreased (P<0.01), however, LVEF wassignificant improved (P<0.01).2. Left ventricular peak systolic longitudinal strain curve of control group is inerraticregular. SLs of basal segment is less than that of middle segment, and SLs of middlesegment is also less than that of apex segment. The above rule could push the bloodflow to the aorta valve.3．In comparison with control group, the SLs and SrLs of myocardial ischemic segmentspreoperative were decreased in CHD group (P<0.05). SLs, SrLs in the correspondingsegments of patients3months postoperative showed significantly improved than thosecomparing to preoperative (P<0.05).4．Compared to control group, the SrLe of myocardial ischemic segments preoperotivewas decreased in CHD group (P<0.05). SrLe in the corresponding segments of patients3months postoperative showed significantly improved than those comparing to preoperative (P<0.05).5. The GLS of apical4-chamble,2-chamble and long axis view and GLS-Avg of CHDgroup preoperative were significantly lower than those of control group（P<0.05）. AfterCABG, the above values were improved (P<0.05). There was good relationship betweenGSL-Avg and LVEF (r=0.85).Conclusion1. STI technology can be used to evaluate the change of regional and global leftventricular function objectively and quantitatively. Therefore, it provides a quantitative,simple, fast, accurate, repeatability and no angle method for measuring LV function forclinical.2. Left ventricular peak systolic longitudinal strain curve of control group is inerraticregular. SLs of basal segment is less than that of middle segment, and SLs of middlesegment is also less than that of apex segment.3. Left ventricular peak systolic longitudinal strain curve of CHD is confused, regionaland global left ventricular function decreased.4. After CABG, the strain data have improved significantly. Therefore, CABG couldameliorate LV function.5. There was good relationship between GSL-Avg and LVEF...