Quantitative Assessment Of Left Ventricle Segment Function In Patient With Ischemic Mitral Regurgitation By2-Dimensional Speckle Tracking Imaging

Background:Mitral regurgitation is a common clinical cardiovascular disease. It is still increasing with the incidence of coronary heart disease. Functional mitral regurgitation caused by myocardial ischemia is also very common. Ischemic mitral regurgitation (IMR) usually occurs as a result of mitral annulas dilatation and papillary muscle displacement secondary to global left ventricle dysfunction and remodeling. The mechanism of IMR is very complex, in which left ventricle segment dysfunction is one of the reasons. We evaluated the segment function of left ventricle in patient with IMR by2-Dimensional Speckle Tracking Imaging (2D-STI) to assess the relationship between IMR and left ventricle segment function.Objective1. To evaluate the left ventricle segment function of the patient after myocardial infarction (MI) with2-Dimensional Speckle tracking imaging.2. To assess the relationship between IMR and left ventricle segment function.3. To assess the influence of IMR on different sites of MI.Methods:2D-STI was performed in59patients with prior MI or regional wall motion abnormality found in routine echocardiography, and in21healthy subjects (Control group). The imaging was analyzed offline with Q-Lab TMQA software to measure the parameters of left ventricle segment function, including the peak systolic circumferential strain (CS)、radial strain (RS)、longitudinal strain (LS)and transverse strain (TS). The parameters of patients with IMR are compared with those of patients without IMR. In addition, the anterior myocardial infarction data are compared with the non-anterior myocardial infarction data.Results: 1. There is regularity of the peak systolic circumferential strain (CS)、radial strain (RS)、longitudinal strain (LS)and transverse strain (TS) in healthy people.2. Patients were divided into2groups according to the degree of MR:No IMR group(MR≤2, n=30) and IMR group(MR>2, n=29). In most of the segments, the peak systolic CS、RS、LS and TS in healthy people is higher than those of the patients (P<0.05).3. Left atrial diameter(LAD)、left ventricle end-diastolic diameter(LVEDd) of patients with IMR is much lager than patients without IMR(P<0.01). Left ventricular ejection fraction (LVEF) of patients with IMR is much lower than that of patients without IMR (P<0.01).4. The left ventricle segment is divided into three areas, including left anterior descending artery perfusion areas, circumflex artery perfusion areas and right coronary artery perfusion areas. In the circumflex artery perfusion areas and right coronary artery perfusion areas, all the parameters of strains in patients with IMR is lower than patients without IMR (P<0.05). But in left anterior descending artery perfusion areas, there is no difference between patients with IMR and patients without IMR.5. Patients were divided into2groups according to the position of MI:anterior MI group and NO-anterior MI group. LVEF of anterior MI group is much lower than that of NO-anterior MI group (P<0.05).But the degree of MR in two groups shows no difference.Conclusion:1. There is a significant decline of left ventricle segment function in patient with MI. The segment dysfunction in patients with IMR is more extensive than patients without IMR. In IMR group all the strains decline significantly in circumflex artery perfusion areas and right coronary artery perfusion areas. Pathological changes of circumflex artery and right coronary artery may cause IMR.2. Anterior MI has more influence on global left ventricle dysfunction and remodeling, but maybe not has the inevitable relationship between IMR.3.2D-STI could be used to quantify LV segment function of MI patient, help us to further define the mechanism of IMR.