目的  通过不同方法缩窄大鼠腹主动脉，比较构建心肌肥厚模型，探讨改良腹主动脉缩窄法（AAC）较传统AAC的优势。   方法  实验大鼠45只，分3组，每组15只。假手术组,在左肾上方分离腹主动脉，不做处理；传统组，经腹正中线切口缩窄腹主动脉直径至 0.70 mm，持续4周；改良组，在左肾上方缩窄腹主动脉直径至 0.45 mm， 持续1周。术后测量大鼠收缩末期室间隔厚度(IVSs) 、收缩末期左室后壁厚度(LVPWs)。取心脏标本测量心脏指数（HW/BW)及左心室指数（LVW/BW)；经HE染色、Masson染色的病理切片，测量心肌细胞横截面积、心肌胶原面积及心肌胶原面积分数。Western blotting检测脑钠肽(BNP)表达水平。   结果  相比假手术组，改良组和传统组大鼠IVSs、LVPWs、心脏指数、左心室指数、心肌细胞横截面积、心肌胶原面积、心肌胶原面积分数和BNP表达水平差异均显著（P<0.05）。在改良组和传统组组间，这些指标差异无统计学意义。   结论  与传统方法相比，改良腹主动脉缩窄法用时短，稳定，模型均一，易复制，心肌肥厚相关指标水平表型相似，可作为建立压力负荷性心肌肥厚模型更为理想的术式。

Objective  To compare effectiveness between the modified and traditional pressure-overload myocardial hypertrophy(POMH) model by abdominal aorta coarctation(AAC) method.    Methods  Totally 45 rats were divided into three groups(n=15 per group), sham group, traditional group, and modified group. In the traditional group, the diameter of the abdominal aorta was narrowed to 0.70 mm through a midline incision for 4 weeks; in the modified group, the diameter of the abdominal aorta was narrowed above the left kidney to 0.45 mm for 1 week, and then the narrowing was lifted postoperatively. The cardiac index, heart weight(HW)/body weight (BW) and left ventricular index, left ventricular weight(LVW)/BW were measured from the heart specimens, and the cross-sectional area of cardiac myocytes, myocardial collagen area, and myocardial collagen area fraction were measured in the pathological sections by HE staining and Masson staining.    Results  Compared with the sham group, the differences in end-systolic interventricular septum thickness(IVSs), left ventricular end-systolic posterior wall thickness (LVPWs), HW/BW, LVW/BW, cardiomyocyte cross-sectional area, myocardial collagen area, myocardial collagen area fraction, and brain natriuretic peptide (BNP) expression levels were statistically significant (P<0.05) in the modified and traditional groups of rats. The differences in these indices were not statistically significant between the modified and traditional groups (P>0.05).    Conclusion  The modified abdominal aortic constriction method  used in this experiment is time-saving, stable, homogeneous and easy to replicate, and is a more ideal approach to establish a rat model of POMH.