中文摘要：

目的：探讨压力负荷诱导大鼠心肌肥厚和左室舒张功能的评价方法。方法：采用横向主动脉缩窄法（TAC）建立压力负荷诱导大鼠心肌重塑模型,应用超声心动图、有创血流动力学检测及心肌组织中羟脯氨酸含量测定等方法评价左室结构和舒张功能。结果：（1）超声心动图测定的TAC组术后3周大鼠左室壁厚度显著大于假手术组[前壁：（1.71±0.11）mm vs（1.43±0.06）mm,P〈0.01;后壁（1.78±0.03）mm vs（1.44±0.02）mm,P〈0.01];TAC组术后3周左室后壁心肌舒张早期运动速度（E＇）与假手术组相比显著下降[（52.1±0.8）mm.s-1vs（63.8±1.5）mm.s-1,P〈0.01],术后6周进一步降低。（2）解剖称重左室重量/胫骨长度在TAC组显著高于假手术组[3周：（19.6±1.1）mg.mm-1 vs（14.8±0.6）mg.mm-1,P〈0.01;6周：（23.2±0.9）mg.mm-1 vs（15.6±0.7）mg.mm-1,P〈0.01]。（3）TAC组校正的左室内压力最大下降速度（dp/dtmin/LVSP）在术后3周有下降趋势（48.9±5.9 vs 63.5±9.9）,术后6周下降显著（35.4±4.0 vs 54.4±2.9,P〈0.01）。（4）天狼猩红染色可见TAC组血管周围胶原沉积明显多于假手术组,术后6周TAC组心肌组织中羟脯氨酸含量显著高于假手术组[（465.3±17.3）μg vs（351.4±8.2）μg,P〈0.05]。结论：超声心动图组织多普勒测定左室后壁心肌运动速度是评价压力负荷心肌重塑大鼠早期左室舒张功能异常的可靠指标。

英文摘要：

AIM： To investigate the evaluation method of left ventricular diastolic function and myocardial hypertrophy induced by pressure overload in rats.METHODS： Male Sprague-Dawley rats were subject to left ventricular pressure overload by transverse aortic constriction（TAC）.Cardiac structure and diastolic function were evaluated by echocardiography,hemodynamic analysis and examination of hydroxyproline concentration in the myocardial tissues.RESULTS： Compared with the sham-operated controls,left ventricular wall dimension in diastole significantly increased in the rats 3 weeks after TAC [anterior wall：（1.71±0.11） mm vs（1.43±0.06） mm,P0.01;posterior wall：（1.78±0.03） mm vs（1.44±0.02） mm,P0.01].Left ventricular early diastolic posterior wall motion velocity（E′） significantly decreased in the rats 3 weeks after TAC[（52.1±0.8） mm·s-1 vs（63.8±1.5） mm·s1,P0.01],and was much lower than that in the rats 6 weeks after TAC.Left ventricular mass to tibia length in TAC rats was much higher than that in sham-operated controls [3 weeks after TAC：（19.6±1.1） mg·mm-1 vs（14.8±0.6） mg·mm-1,P0.01;6 weeks after TAC：（23.2±0.9） mg·mm-1 vs（15.6±0.7） mg·mm-1,P0.01].The ratio of maximum rate of degression of left ventricular pressure（dp/dtmin） to left ventricular systolic pressure（dp/dtmin/LVSP） started to decrease in TAC rats in the 3rd week（48.9±5.9 vs 63.5±9.9） and significantly decreased in TAC rats in the 6th week as compared with sham-operated controls（35.4±4.0 vs 54.4±2.9,P0.01）.Sirius red-stained collagen in cardiac interstitium,especially around the blood vessels,was increased in TAC rats.Six weeks after TAC,a significant increase in the content of myocardial hydroxyproline[（465.3±17.3） μg vs（351.4±8.2） μg,P0.05] was observed.CONCLUSION： The early diastolic posterior wall motion velocity（E′） detected by tissue Doppler imaging is a sensitive indicator of diastolic dysfunction at the early stage of myocardial remodeling