Estimation Of Left Ventricular Global Function By The Doppler Tei Index In The Early Phase Of Acute Myocardial Infarction

Aims To study the change of left ventricular function in the early phase of AMI patients by Tei index and left ventricular ejection fraction (LVEF, measured by biplane Simpson methed), and to make a analysis about the associativity between the two indices. To investigate the effect of identifying CHF and evaluating prognosis in patients of AMI, and to discuss the relation between the degree of coronary artery's stenosis of AMI and Tei Index.Methods 64 patients with Acute Myocardial Infarction from 2005 to 2007 were selected in a consecutive manner as AMI group,and 65 normal person matched with AMI group in age, gender were selected as control group.38 patients accepted coronary angiography and successful PCI(13 immediate PCI, 25 delayed PCI), 13 patients underwent successful urokinase thrombolytic therapy, 13 patients underwent no reperfusion therapy. During inhospital period,64 AMI patient's ventriCular function were divided into 4 grades by Killip grade, include Killip gradeⅠ(n=33), Killip gradeⅡ(n=18), Killip gradeⅢ(n=10),Killip gradeⅣ(n=3). Incorporate Killip gradeⅡ-Ⅳinto one group of with congestive heart failure(CHF),and take Killip grade I as the other group of without CHF. Coronary angiography of 38 patients accepted PCI suggested 14 patients did with one vessel disease, 16 patients with two vessel disease and 8 patients with three vessel disease,and suggested 15 patients with mild stenosis, 16 patients with moderate stenosis and 7 patients with severe stenosis. The first Echocardiography examinations were performed within 6-48 (mean 12.8±8.4)hours of patient's arrival at the hospital. The second Echocardiography examinations were performed about30 (mean 29±1.5)days after therapy. From standard parasternal long axis view, IVS,LVPWD,LVDd,LVSd were measured by M-mode. From apex four chanmber view and two chanmber view, LVEDV,LVESV were measured and LVEF was calculated by apex biplane Simpson method. Tei index was measured by pulse blood Doppler, and was calculated by the follow formula, Tei index=(IRT+ICT)/ET=(a-b)/b. a was the interval between end and onset of the mitral inflow, and b was the ejection time of aorta..Results LVDd,LVDs,LVEDV and LVESV were increased in AMI group compared with control group. The mean value of the Tei Index and LVEF were significantly different between the AMI group and the control group, respectively. In all involved, there was a significant correlation between Tei index and LVEF(control group: r=-0.83,p＜0.001;AMI group: r=-0.79 P＜0.001).Tei index was significantly increased from Killip grades≥Ⅱ, and Killip grades was midrange correlated with Tei index and LVEF (Tei index r=0.41,p＜0.01 LVEF r=-0.32, p＜0.01), respectively。Using Tei Index≥0.52 as the best cutpoint of CHF identified, Tei Index did with a sensitivity of 72％,a specificity of 92％and a accuracy of 75％. Tei index's sensitivity, specificity and accuracy was beter than LVEF,.respectively.The mean Tei-Index of mild stenosis was significantly different compared with moderate stenosis's and severe stenosis's, but there wasn't different in Tei index between moderate stenosis and sever stenosis.Through the comparison of two-time result of Echocardiography for 58 survivor of AMI group, found that Tei index and LVEF improved obviously after a period of time of in-hospital therapy, but Tei index and LVEF of the second Echocardiography of AMI group were still abnormal compared with control group's. The rangeability of Tei index and LVEF of PCI group and thrombolytic therapy group took obviously difference with no reperfusion therapy group's. There was significant difference in Tei index, but no difference in LVEF in the rangeability between PCI group and thrombolytic therapy group before and 30 days after therapy. Conclusions: (1) Both Tei index and LVEF could accurately reflect the change of the left ventricular function at the time of attack and after a period of time of therapy, and Tel index was better than LVEF for estimating left ventricular function,because which reflected overall left ventricular function.(2) Tei index was better than LVEF in the sensitivity, the specificity and the accuracy of identifying CHF.(3) Tei index was also able to reflect the degree of coronary artery's stenosis of AMI, the higher Tel index was, the more severe coronary artery's stenosis of AMI possibly was.(4) This simple and reproducible Doppler Tei index was a reliable and practical method and was also a new expansion of method for Echocardiography estimating left ventricular systolic and diastolic functions.