【摘要】 目的探讨构建心肌梗死模型的大鼠左冠状动脉结扎位置及心电图特点。方法 SD大鼠经麻醉后,气管切开插管及连通呼吸机,打开左侧胸腔后分别在距离左心耳尖端约2 mm水平处(低位结扎组)与在距主动脉根部约3 mm处(高位结扎组)结扎左冠动脉,假手术组除不结扎冠脉外步骤同低位结扎组,术前术后分别行心电图检查,且4周后取出心脏行病理学检查及测定心肌梗死面积。结果高位结扎组大鼠心肌梗死面积约55.5%,总存活率13.3%;低位结扎组大鼠心肌梗死面积约36.2%,总存活率66.7%;假手术组大鼠无心肌梗死,存活率100%。大鼠体表心电图在非心肌梗死者QRS-T波群呈成"M"型波,在心肌梗死者R波与T波融合成高大的帐篷状单波,无明显ST段。4周后心肌组织形态学特点符合心肌梗死的病理改变。结论距大鼠主动脉根部约3 mm结扎左冠状动脉,不能满足实验需要;距离左心耳尖端约2 mm水平结扎左冠状动脉,能满足实验需要;大鼠的体表心电图无明显ST段。更多还原

【Abstract】 Objective To explore the site of left coronary artery ligation on establishing myocardial infarction model and the electrocardiographic features in those rat models.Methods After the Sprague-Dawley(SD) rats were anaesthetized and put on chine-assisted respiration,an occluding suture was placed at one of two distinct sites along the left coronary artery.The suture was placed about 3 mm distal to the aortic root(high) and about 2 mm distal to the horizontal line of left atrial appendage tip(low),respectively,and underwent the same procedure as the low suture group except left coronary artery ligation(sham),monitored by electrocardiography(ECG) before and after operation,respectively.At 4 weeks after operation they were sacrificed for histopathological analysis and measurement of the infarct area.Results The infarct area was about 55.5% and 36.2%,and the total survival rate was 13.3% and 66.7% in the high and low suture groups,respectively.There was no myocardial infarction and the survival rate was 100% in the sham operation group.ECG: QRS-T wave displayed an intersection "M" shape in the sham group and before left coronary artery ligation.The R wave and T wave fused into one large tent-like single wave after the left coronary artery ligation,and without visible ST segment.Histopathological changes of myocardial infarction were seen at 4 weeks after operation.Conclusions It is a novel method to establish myocardial infarct model that the suture is placed about 2 mm distal to the horizontal line of left atrial appendage tip,and all ECG showed no visible ST segment in the rats.更多还原