Saraiva R M, Kanashiro-Takeuchi R M, Antonio E L, Campos O, P J F Tucci, Moisés V A
Disciplina de Cardiologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São PauloSão Paulo, SP, Brasil.
Braz J Med Biol Res. 2007 Nov;40(11):1557-65. doi: 10.1590/s0100-879x2007001100016.
The severity of left ventricular (LV) dysfunction in rats with myocardial infarction (MI) varies widely. Because homogeneity in baseline parameters is essential for experimental investigations, a study was conducted to establish whether Doppler echocardiography (DE) could accurately identify animals with high LV end-diastolic pressure as a marker of LV dysfunction soon after MI. Direct measurements of LV end-diastolic pressure were made and DE was performed simultaneously 1 week after surgically induced MI (N = 16) or sham-operation (N = 17) in female Wistar rats (200 to 250 g). The ratio of peak early (E) to late (A) diastolic LV filling velocities and the ratio of E velocity to peak early (Em) diastolic myocardial velocity were the best predictors of high LV end-diastolic pressure (>12 mmHg) soon after MI. Cut-off values of 1.77 for the E/A ratio (P = 0.001) identified rats with elevated LV end-diastolic pressure with 90% sensitivity and 80% specificity. Cut-off values of 20.4 for the E/Em ratio (P = 0.0001) identified rats with elevated LV end-diastolic pressure with 81.8% sensitivity and 80% specificity. Moreover, E/A and E/Em ratios were the only echocardiographic parameters independently associated with LV end-diastolic pressure in multiple linear regression analysis. Therefore, DE identifies rats with high LV end-diastolic pressure soon after MI. These findings have implications for using serial DE in animal selection and in the assessment of their response to experimental therapies.
心肌梗死（MI）大鼠左心室（LV）功能障碍的严重程度差异很大。由于基线参数的同质性对于实验研究至关重要，因此开展了一项研究，以确定多普勒超声心动图（DE）能否准确识别左心室舒张末期压力高的动物，作为心肌梗死后不久左心室功能障碍的标志物。在雌性Wistar大鼠（200至250克）中，手术诱导心肌梗死后1周（N = 16）或假手术后1周（N = 17），直接测量左心室舒张末期压力并同时进行DE检查。舒张早期（E）与晚期（A）左心室充盈速度之比以及E速度与舒张早期心肌速度峰值（Em）之比是心肌梗死后不久左心室舒张末期压力高（>12 mmHg）的最佳预测指标。E/A比值的截断值为1.77（P = 0.001），可识别左心室舒张末期压力升高的大鼠，敏感性为90%，特异性为80%。E/Em比值 的截断值为20.4（P = 0.0001），可识别左心室舒张末期压力升高的大鼠，敏感性为81.8%，特异性为80%。此外，在多元线性回归分析中，E/A和E/Em比值是与左心室舒张末期压力独立相关的唯一超声心动图参数。因此，DE可识别心肌梗死后不久左心室舒张末期压力高的大鼠。这些发现对于在动物选择中使用连续DE以及评估它们对实验性治疗的反应具有重要意义。
