| Background and ObjectivesAt present, the world each year,17million people die of cardiovascular disease,more than half of them died of acute myocardial infarction (AMI). In recent10years, ourcountry increased the incidence of AMI, is close to the international average level. AMI asa severe type of coronary heart disease, often can be life-threatening, early heart functionin patients with myocardial infarction, to conduct a comprehensive and accurateevaluation, to guide clinical diagnosis and treatment, judgment after has importantapplication value. Anterior wall myocardial infarction occupies large proportion in theincidence of myocardial infarction, prone to left ventricular（LV） remodeling after AMI,had the greatest influence on left ventricular ejection function (LVEF), much larger impacton cardiac function LV posterior wall (PW) or inferior wall (IW) myocardial infarction. Therefore this study for acute anterior wall myocardial infarction cardiac functionevaluation research. The main method of current clinical cardiac function evaluation isstill the traditional two-dimensional echocardiography, this method relies mainly on thediagnosis of the doctor’s eye identification and experience judgment, subjectivedependence is bigger. In addition currently accepted clinical cardiac function evaluationindex, there are also shortcomings. In view of the above problem, this study applies thetracking of mitral annular displacement （TMAD） and strain rate imaging,(SRI) bothtechniques for evaluation of cardiac function research, focus on the whole LV systolicfunction and regional myocardial systolic and diastolic function in patients with AMI, inorder to make up for the inadequacy of conventional cardiac function evaluation methods.Mitral annular displacement (MAD) as an important mechanism to participate in thepumping process, is considered to reflect the overall index of LV systolic function. TMADis based on the speckle tracking technology, the semi-automatic method to trackmovement of mitral annular relative to the ventricular apex department to evaluate LVfunction. This new method to the quantitative analysis of mitral annular motionparameters can evaluate LV overall systolic function, the method is simple and reliable.SRI is developed based on doppler tissue imaging (DTI), intuitively, and a precisequantitative analysis of ventricular regional myocardial function change to evaluate thecardiac local function providing an important quantitative index. SRI detection isrelatively unaffected by myocardium and heart whole moving around. Time and spatialresolution is very high, which can accurately evaluate the local myocardial systolic anddiastolic movement. This method and be used to evaluate the local myocardial systolicand diastolic function, can early detect of cardiac function in patients with acute anteriorwall myocardial infarction. Myocardial infarction is one of the main causes of death incardiovascular disease. TMAD can early and sensitively determine heart LV globalsystolic function in patients with AMI. SRI can evaluate LV and right ventricular（RV） inpatients with AMI regional myocardial systolic and diastolic function. Acute anterior wallmyocardial infarction with RV involvement, and its clinical manifestations can be LV function dysfunction cover up. Improper treatment may induce severe hemodynamicdisorders and even death, so early detection of LV and RV function after myocardialinfarction has important guiding significance for clinical diagnosis and treatment andprognosis. This study aims to:1. Application TMAD in patients with AMI evaluated LVsystolic function as a whole.2. To evaluate AMI patient’s LV regional myocardial systolicand diastolic function using SRI.3. Evaluation of RV function in acute left ventricularanterior myocardial infarction by use of SRI.Methods and results:Application TMAD and SRI technology, respectively evaluation of patients withAMI, LV global function in patients with AMI,LV and RV regional myocardialcontraction, diastolic function. In20patients with AMI group, all of the patients bymedical history, clinical presentation, myocardial enzymes, electrocardiogram andcoronary artery angiography confirmed diagnosis for acute anterior wall myocardialinfarction.20patients of single lesions in6cases,2lesions in10cases,4cases werelesions in3, myocardial bridge in2cases, concurrent thrombosis in2cases and30casesof normal control group. Take apex fourth chamber view, two chamber view and long axisview for shaft section six sites in three groups of mitral annular MAD were determined.Assessment of LV systolic function as a whole was performed. Based on the abovesection, we measured LV and RV wall the basal parts of the wall, middle, apex of systolicand diastolic early, atrium contraction peak strain rate (SRS, SRE, SRA), evaluation ofpatients with AMI of left and right ventricular regional myocardial function. SRI data werecompared with coronary angiography results and analysis in patients with AMI of the LVand RV regional myocardial function.The result shows that:1. TMAD in patients with acute anterior wall myocardial infarction of whole LVsystolic function assessment: AMI group of MAD respectively than control groupsignificantly reduced.2. Application of strain rate imaging in patients with AMI assessment LV region myocardial contraction and diastolic function.SRs:all LV walls (Base, middle level) and those of other walls except for IW of apicallevel significantly decreased in AMI group;SRE：all levels of LV wall in AMI group were significantly lower than those of thecontrol group;SRA: basal level of AS、PW、AW、IW, middle level of post septal (PS)、PW、AW andapex level of PS、AW、IW in AMI group were also significantly decreased compared withcontrol group.3. Evaluation of RV function in acute left ventricular anterior myocardial infarction byuse of SRI. Results SRs:all levels of PS (Base, middle and apical) and base RV wallsignificantly decreased in AMI group; SRE：all levels of PS and base and middle levels ofRV in AMI group were significantly lower than those of the control group; SRA: middleand apex level of PS in AMI group were also significantly decreased compared withcontrol group.Conclusion:1. Evaluation of LV overall systolic function in patients with acute anterior wallmyocardial by TMAD technology, AMI group of MAD than normal subjects significantlyreduced. TMAD method can be performed by measuring of six sites of MAD evaluationLV systolic function as a whole in patients with AMI.2. Application of SRI technology of quantitative evaluation of patient with AMI eachLV local myocardial systolic and diastolic function.AMI and normal control group leftventricular wall of different segments of the longitudinal SR, observed the AMI groupcompared with normal control group, different levels of LV SRs and SREeach wall weresignificantly reduced. SRI change and reflect the overall systolic and diastolic function ofthe index changes agree with. From each section of the AMI myocardium of measuringvalue analysis, the influence on left ventricular myocardial infarction in addition to themyocardial infarction wall because most of the selected cases with multiple lesions, butalso affect the other wall section.. 3. SRs、SRE, of RV wall in significantly decreased in AMI group.In LV acute ischemia,LV function change at the same time, there is a change right heart function also change.TMAD technology of image quality is low, no angle dependence, especially inmeasuring LVEF are more clinical significance are in trouble, but it can only be used forevaluation of whole LV systolic function, unable to evaluation of regional myocardialfunction. For this reason, SRI technology was applied to local myocardial contraction anddiastolic function to do in order to evaluate, the method can early, sensitively determineAMI patients with LV and RV myocardium local contraction and diastolic function.Combining the above two kinds of new technology will noninvasive,quantitative thecomprehensive assessment of cardiac function in patients with AMI, especially in theanterior wall myocardial infarction with RV involvement, early detection of left and rightventricular function after myocardial infarction on clinical diagnosis and treatment andjudge the positive value of application. |
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