摘要目的 探讨低龄低体质量小鼠心肌梗死模型的建立方法.方法 小鼠3.3％水合氯醛腹腔麻醉,经口气管插管,呼吸机辅助,左侧开胸结扎左冠状动脉前降支,术中监测心电图变化.术前、术后第5天和第17天行心脏超声检查；术后第8周心脏病理检查.结果 结扎瞬间可见心电图ST段呈弓背形向上抬高,结扎点周围心肌颜色变白.心脏超声可见左心室收缩期及舒张期前、后壁变薄,窒壁运动减弱,心室内径增大,左窒舒张末直径由(3.42±0.36) mm扩大至(5.92±0.66) mm(P ＜0.05),收缩末直径由(2.15±0.32) mm扩大至(5.46±0.77) mm(P＜0.05).病理检查可见左心窒心腔明显增大,心肌变薄；心肌纤维卷曲、断裂、坏死.结论 迅速、准确的气管插管；良好的手术视野暴露；左冠脉前降支的正确识别和结扎；气胸的预防、鉴别和甲期处理,是成功建立低龄低体质量小鼠心肌梗死模型的关键.

abstractsObjective To investigate the method of establishing myocardial infarction model in young mice of low body weight.Methods After being anaesthetized with 3.3％ chloral hydrate,the mice was intubated through oral tracheal and breathed with the assistance of ventilator.Then a left anterior thoraeotomy was performed to ligate the left anterior descending (LAD) coronary artery.During the surgery,changes in the ECG were monitored.The mice were examined by transthoracic echocardiography before and 5,17 days after the surgery.At the 8th week,the heart was detected by pathological examination.Results ECG showed elevated ST segment instantly when the LAD coronary artery was ligated and the myocardium became pale around the ligation points.Heart ultrasound showed there was progressive decline in the thickness of left cardiac ventricle and increase in the left ventricular diameter,and the wall motion was weakened.The end dilation dimensio and end systolic dimensio were increased significantly [ ( 3.42 ± 0.36) mm and (2.15 ± 0.32 ) mm vs (5.92 ± 0.66) mm and ( 5.46 ± 0.77 ) mm,P ＜ 0.05 ].Pathologic examination revealed the size of the left ventricular cavity was increased obviously and the myocardium thickness was decreased; The myocardial fibers became frizzy,fractured and necrotic.Conclusion Intubating quickly and correctly,exposing surgical field clearly,identifying and ligating LAD coronary artery correctly,and preventing,identifying and treating pneumothorax early were the keys in establishing a successful myocardial infarction model in young mice of low body weight.