应用高频超声评价小鼠缺血性心肌病左室重塑的实验研究

目的应用15MHz线阵超声探头评价小鼠缺血性心肌病左室重塑的发生规律，探讨缺血性心肌病左室形态功能障碍的发生机制。 方法60只昆明小鼠随机分为两组，其中一组45只小鼠行开胸左冠状动脉高位结扎术为手术组，另一组15只仅开胸不结扎左冠状动脉为假手术组。两组应用15MHz高频线阵探头分别于术前、术后1、2、4、6周行经胸心脏超声检查。并于术后6周时行微导管血流动力学及病理学检查。 结果超声观察到缺血性心肌病左室重塑开始于模型制作成功后第1周，并于第6周最为显著，表现为：早期梗死区的过度伸展，左室舒、缩末内径，左室舒张末外径，左室质量显著增加（P均〈0．05），左室前壁厚度、左心室短轴缩短率和血流动力学指标的显著降低（P均〈0．05）。 结论高频超声是一种可靠无创的连续评价手段，小鼠心肌缺血后梗死区的早期伸展是左室发生心肌病样重塑的主要原因。

Serial Echocardiographic Assessment of Left Ventricular Remodeling in Murine Ischemic Cardiomyopathy Model with High Frequency Ultrasound

Objective To use serial echocardiography assessment of left ventricular (LV)remodeling in Kun Ming mice(KM) with ischemic cardiomyopathy with a high frequency ultrasound(HFU).Methods Sixty KM mice underwent open-chest surgery to induce left coronary artery occlusion or sham-operation (SH).Echocardiography was performed with a 15 MHz HF linear array transducer before and at 1,2,4 and 6 weeks after surgery.Hemodynamics were determined at 6th week via LV catheterization and hearts were examined morphologically.Results In survival ischemic mice,LV dilatation and decreased in fractional shortening(FS)were detected with HF transducer at 1 week.LV dimension,LV mass were progressively increased and FS were declined during the 2-6 week period.Infarcted mice had worse hemodynamics compared with that SH did. Conclusions Echocardiography with 15 MHz HF transducer was a reliable means to serially assess LV remodeling and to accuralely evaluate LV dysfunction.