Zhang Yan, Takagawa Junya, Sievers Richard E, Khan Muhammad F, Viswanathan Mohan N, Springer Matthew L, Foster Elyse, Yeghiazarians Yerem
Division of Cardiology, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143-0124, USA.
Am J Physiol Heart Circ Physiol. 2007 Feb;292(2):H1187-92. doi: 10.1152/ajpheart.00895.2006. Epub 2006 Oct 6.
The aim of this study was to determine the feasibility and accuracy of wall motion score index (WMSI) and myocardial performance index (MPI) for measuring regional and global left ventricular (LV) function with use of high-resolution echocardiography after myocardial infarction (MI) in mice. In 48 mice, myocardial infarction was induced by ligation in the middle of the left anterior descending coronary artery. Echocardiography was performed under anesthesia at baseline and 1 mo after MI. WMSI was analyzed by a 16-segment model on short-axis views, and wall motion was scored as 1 for normal, 2 for hypokinetic, 3 for akinetic, 4 for dyskinetic, and 5 for aneurysmal. WMSI was calculated as the sum of scores divided by the total number of segments. MPI was calculated on the basis of isovolumetric contraction time (IVCT), isovolumetric relaxation time (IVRT), and ejection time (ET): MPI = (IVCT + IVRT)/ET. We measured LV ejection fraction (LVEF), end-systolic and end-diastolic volumes (ESV and EDV), fractional shortening (FS), and infarct size (IS). LVEF at 4 wk after MI was reduced at 32.8 +/- 9.0%. Linear correlation analyses showed that WMSI (1.6 +/- 0.3) correlated with LVEF (r = -0.84, P < 0.0005), FS (r = -0.43, P = 0.003), and IS (34.3 +/- 15.3%, r = 0.86, P < 0.0005). MPI (0.67 +/- 0.09) correlated with LVEF (r = -0.67, P < 0.0005) and IS (r = 0.72, P < 0.0005). MPI also correlated with mitral inflow velocity (r = -0.68, P < 0.0005) and deceleration time (r = -0.42, P = 0.003). Stepwise regression analysis revealed that WMSI was independently associated with IS. IS, FS, mitral inflow velocity, and deceleration time were independent determinants of MPI. In conclusion, echocardiographic assessments of WMSI and MPI in mice are feasible and correlate strongly with two-dimensional measurement of LV function and IS. These novel parameters provide additional noninvasive assessment of regional and global LV function in mice after MI.
本研究的目的是确定在小鼠心肌梗死（MI）后使用高分辨率超声心动图测量局部和整体左心室（LV）功能时，室壁运动评分指数（WMSI）和心肌性能指数（MPI）的可行性和准确性。在48只小鼠中，通过结扎左前降支冠状动脉中部诱导心肌梗死。在基线和MI后1个月时，在麻醉状态下进行超声心动图检查。通过短轴视图上的16节段模型分析WMSI，室壁运动评分如下：正常为1分，运动减弱为2分，运动消失为3分，运动障碍为4分，室壁瘤为5分。WMSI计算为评分总和除以节段总数。MPI根据等容收缩时间（IVCT）、等容舒张时间（IVRT）和射血时间（ET）计算：MPI =（IVCT + IVRT）/ET。我们测量了左心室射血分数（LVEF）、收缩末期和舒张末期容积（ESV和EDV）、缩短分数（FS）以及梗死面积（IS）。MI后4周时LVEF降低至32.8±9.0%。线性相关分析显示，WMSI（1.6±0.3）与LVEF（r = -0.84，P < 0.0005）、FS（r = -0.43，P = 0.003）和IS（34.3±15.3%，r = 0.86，P < 0.0005）相关。MPI（0.67±0.09）与LVEF（r = -0.67，P < 0.0005）和IS（r = 0.72，P < 0.0005）相关。MPI还与二尖瓣流入速度（r = -0.68，P < 0.0005）和减速时间（r = -0.42，P = 0.003）相关。逐步回归分析显示，WMSI与IS独立相关。IS、FS、二尖瓣流入速度和减速时间是MPI的独立决定因素。总之，对小鼠进行WMSI和MPI的超声心动图评估是可行的，并且与LV功能和IS的二维测量密切相关。这些新参数为MI后小鼠局部和整体LV功能提供了额外的非侵入性评估。
