Abstract: Objective  To investigate the changes of mitral valve configuration in patients with ischemic mitral regurgitation(IMR) in different infarct sites by transthoracic real-time three-dimensional echocardiography, and to analyze the influencing factors of the degree of regurgitation, so as to provide reference for clinical treatment.
Methods  A total of 64 patients with myocardial infarction(MI) and IMR were included as the case group. According to the location of MI, the patients were divided into anterior MI subgroup(n=40) and inferior MI subgroup(n=24), and 45 healthy volunteers were included as the control group.The ultrasonic quantitative parameters included left ventricular end-diastolic volume(LVEDV), left ventricular end-systolic volume(LVESV), left ventricular ejection fraction(LVEF), anterior-to-posterior diameter(DAP), annular height(AH), commissural diameter(CD), three-dimensional annular area(A3D ), non-planar angle(NPA), tenting volume(VTent), tenting height(HTent), three-dimensional annular circumference(AC), and posterior leaflet angle(θPost). The changes of mitral valve configuration between each group were compared and the influencing factors of the degree of IMR were analyzed by multinomial Logistic regression.
Results  LVESV and LVEDV in anterior MI subgroup and inferior MI subgroup were all higher than those in the control group, while LVEF was significantly lower than that in the control group; LVESV and LVEDV in anterior MI subgroup were larger than those in the inferior MI subgroup, while LVEF was smaller than that in the inferior MI subgroup, and the differences were statistically significant(P＜0.05). DAP, CD, A3D, HTent, VTent, AC, NPA and θPost in anterior MI subgroup and inferior MI subgroup were all higher than those in the control group, while AH was lower than that in the control group, and the differences were statistically significant(P＜0.05). CD, A3D, VTent and HTent in anterior MI subgroup were larger than those in the inferior MI subgroup, while θPost was smaller than that in the inferior MI subgroup, and the differences were statistically significant(P＜0.05). No significant difference was found in DAP, AH, NPA and AC between anterior MI subgroup and inferior MI subgroup(P＞0.05). The incidence of severe IMR in the inferior MI subgroup was higher than that in the anterior MI subgroup, and the difference was statistically significant(P＜0.05). Multinomial Logistic regression analysis showed that VTent and θPost were risk factors for severe IMR.
Conclusion  The formation mechanism of IMR in anterior MI subgroup and inferior MI subgroup is different. VTent and θPost are risk factors for severe IMR. This result is beneficial to the choice of surgical procedure in clinical practice.

Key words: mitral valve insufficiency, myocardial infarction, echocardiography, three-dimensional