小型猪急性心肌梗死模型的建立及血流评价

Establishment and hemodynamics assessment on acute myocardial infarction model in pigs

目的探索结扎小型猪冠状动脉左前降支(LAD)建立急性心肌梗死(MI)模型及进行血流评价的方法。方法小型猪20头,全麻下开胸暴露心脏,预阻断冠状动脉左前降支(第2对角支)15 min后予以结扎。术中进行心电图动态监测,术后进行冠状动脉造影及检测血清心肌酶谱以确定模型建立的情况。以冠状动脉造影评价MI溶栓治疗的血流分级(TIMI-FG);13氮-氨正电子发射断层显像(13N-NH3PET)测定心肌血流评价手术后血流的改变。结果在小型猪20头中有16头存活4周,成活率80%。开胸手术中1头因麻醉意外死亡,3头死于术后呼吸不畅。结扎后,心电图呈动态变化,24 h后血清心肌酶谱(肌酸激酶、肌酸激酶同工酶、肌钙蛋白I)的水平较术前明显增高(P<0.01)。冠状动脉造影显示,LAD血流中断证实MI模型建立成功。术后3 d,冠脉造影血流TIMI分级及13N-NH3PET测定心肌血流量较术前有明显变化。结论开胸手术成功率高,术后血流评价方法可用于手术前后冠脉血流和心肌血流的比较,以及对MI后治疗的效果进行评价。

AIM To explore the method to establish an animal model of myocardial infarction with ligation of the left anterior descending coronary artery （LAD） and the method to evaluate it. METHODS Twenty normal Chinese miniswine underwent thoracotomy under general anesthesia. The LAD was obstructed for 15 minutes and then was ligated at the opening of the second diagonal branch. Acute myocardial infarc- tion was confirmed by electrocardiogram, angiography and serum myocardial zymogram examination. Hemodynamics was assessed by TIMI-FG and 13N-NH3 PET. RESULTS Of the 20 animals, 16 sur- vived for 4 weeks, one died of anesthesia accident and three died of aspiration failure after operation. EKG displayed continuous elevated ST and pathologic Q wave after ligation. Serum myocardial zymogram showed that creatine kinase （CK）, ereatine kinase isoenzyme MB （CK-MB） and cardiac troponin-I （CTn-I） increased 24 hours after operation and were significantly different compared with those before operation （P 〈0. 01 ）. CAG showed that the blood flow under the second branch of LAD was interrupted. TIMI-FG and D/E （%） after operation was significantly different compared with that before operation. CONCLUSION The surgical procedure has a high success rate. The hymodynamics assessment can be used to measure the blood flow of the coronary artery and to evaluate the treatment effect of myocardial infarction.