定量组织速度成像评价强力霉素对扩张型心肌病大鼠左心室收缩功能的影响

目的　应用定量组织速度成像技术(QTVI)评价基质金属蛋白酶抑制剂强力霉素对扩张型心肌病(DCM)大鼠模型左心室收缩功能的影响。方法　QTVI技术测量健康大鼠、DCM大鼠和强力霉素早期干预治疗后DCM大鼠二尖瓣环两个位点(后间隔和左室侧壁)的收缩期长轴方向峰值运动速度 (Vs),M型超声测量健康大鼠和DCM大鼠的左室舒张末期内径(LVEDd)、短轴缩短率 (FS)及射血分数 (LVEF)。结果　DCM大鼠超声测量值与正常大鼠之间差异具有显著性意义(P<0. 05);强力霉素治疗后DCM大鼠的LVEF、FS及Vs均高于未行干预治疗的DCM大鼠(P<0. 05),LVEDd小于未干预治疗的DCM大鼠(P<0. 05);所有大鼠的二尖瓣环两个位点Vs的平均值与LVEF(r=0. 86,P<0. 001)、FS(r=0. 83, P<0. 001)分别高度相关。结论　QTVI技术能无创性定量评价强力霉素有效限制DCM大鼠左室重构、改善左室收缩功能的作用。

Effects of matrix metalloproteinase inhibitor doxycycline on left ventricular systolic function in rats with dilated cardiomyopathy evaluated by quantitative tissue velocity imaging

Objective To assess the regional systolic function of the left ventricle in rats with dilated cardiomyopathy (DCM) after administration of matrix metalloprotease (MMPs) inhibitor doxycycline by quantitative tissue velocity imaging (QTVI).Methods Eleven healthy rats,6 rats with DCM and 7 rats with DCM administered with doxycycline in early stage were studied.The longitudinal velocity during systole(Vs) of the two points at the mitral annulus (posterior inter-ventricular septum and left ventricular lateral wall ) was measured by QTVI.Left ventricular end-diastolic dimension (LVEDd),fractional shortening (FS),and left ventricular ejection fraction (LVEF) were obtained by M-mode echocardiography.Results The echocardiographic data were significantly different between healthy and DCM rats (P<(0.05)).LVEF,FS and Vs in DCM rats treated with doxycycline were significantly higher than those of the untreated DCM rats,except lower LVEDd.Mean Vs of the two points mentioned above were closely correlated with LVEF (r=(0.86),P<(0.001)) and FS (r=(0.83),P<(0.001)).Conclusions QTVI can be used to non-invasively and accurately assess the effects of MMPs inhibitor doxycycline on preventing the left ventricle from remodeling and on improving the ventricular systolic function in DCM rats.