Evaluation of papillary muscles function in myocardial infarction patients using 2D speckle tracking imaging

Abstract

Objective To investigate papillary muscle function and construction in myocardial infarction(MI) patients by two-dimensional speckles tracking imaging(2D-STI), and to analyze the influence factors of ischemic mitral regurgitation. Methods Fifty myocardial infarction with ischemic mitral regurgitation(IMR) patients were brought into case group. The patients were divided into two groups: Ant-MI group and Inf-Pos-MI group. Forty-five health volunteers were involved as control group. Anterior, posterior papillary muscle longitudinal strain (ALS, PLS), delay time(DT), fractional shortening (FS), length between the posterior or anterior papillary muscle tips and the contralateral anterior mitral annualr(APM-AMA, PPM-AMA), mitral leaflet closure(MLC), inter distance papillary muscle(IPMD) were aquired respectively. Papillary muscle function and construction among the groups were compared, and the effective factors of IMR were evaluated. Results Between the control group and Ant-MI group, the left ventricular end-diastolic diameter(LVEDD), left ventricular end-diastolic and end-systolic volume(LVEDV, LVESV), left ventricular ejection fraction(LVEF), ALS, delay time(DT), A-FS, IPMD, MLC, APM-AMA, PPM-AMA were significantly different(all P<0.05). Between the control group and Inf-Pos-MI group the LVEDD, LVEDV, LVESV, EF, DT, PPM-AMA, MLC, PLS, P-FS were significantly different(P<0.05). Between the Ant-MI group and Inf-Pos-MI group, the LVEDD, LVEDV, LVESV, EF, MLC, ALS, PPM-AMA, PLS were significantly different(all P<0.05). In the Ant-MI group, LVEDV, ALS, MLC were significantly correated with Gensini score(r=0.71, -0.65, 0.56; P<0.05). In the Inf-Pos-MI group, PPM-AMA, PLS were significantly correated with Gensini score(r=0.65, -0.76; P<0.05). In the Ant-MI group and Inf-Pos-MI group, the ALS, PLS, PPM-AMA were significantly different(P<0.05). Its correlates in Logistic analysis of Ant-MI group included LVEDV, MLC, DT with OR 1.48, 1.72, 1.54(P<0.05), respectively.Its correlates in logistic analysis of Inf-Pos-MI group included PLS, PPM-AMA, DT with OR 1.78, 1.57, 1.56(P<0.05), respectively. Conclusions There are different extent of damage of papillary muscle function and construction in Ant-MI group and Inf-Pos-MI group. The increases of LVEDV and MLC and desynchronization of PMs are risk factors of IMR in Ant-MI group. The increases of PMP-AMA, decrease PLS and desynchronization of PMs are risk factors of IMR inInf-Pos-MI group. Key words: Echocardiography; Mitral vavel regurgitation; Myocardial infarction; Speckle tracking imaging; Papillary muscle function