犬急性心肌梗死早期冠状动脉旁路移植术对左室壁运动的影响

Effect of early coronary artery bypass grafting to the left ventricular wall motion state in dogs with acute myocardial infarction

目的探讨犬急性心肌梗死早期冠状动脉旁路移植术对室壁运动的影响及其在唤醒冬眠心肌中的意义。方法结扎犬冠状动脉前降支制备心肌梗死模型（30只）。按手术日期随机分组，分别在心肌梗死后1、2、4、6周行冠状动脉旁路移植术作为实验组，其中第2周4只，其余每组6只；对每个实验组分别设立心肌梗死对照组（不进行冠状动脉旁路移植术），每组2只。实验组在冠状动脉旁路移植术前及冠状动脉旁路移植术8周后开胸利用多巴酚丁胺超声负荷试验结合组织多普勒成像技术标记冬眠心肌，并测定室壁运动记分；对照组在相同时间点同样的方法标记冬眠心肌并测定室壁运动记分。每只犬处死后分别测定心肌梗死面积。结果每个实验组各存活4只，对照组均存活。1、2周实验组较4、6周实验组及对照组梗死区心肌室壁运动记分的变化明显减小（0．03±0．06，0．05±0．09，0．23±0．08，0．27±0．06，0．32±0．05，P〈0．05），所有实验组较对照组心肌室壁运动记分的变化明显减小（1．195±0．09，1．25±0．18，1．30±0．18，1．36±0．11，1．65±0．17，P〈0．05），所有实验组较对照组唤醒更多的冬眠心肌（0．27±0．12，0．22±0．04，0．31±0．09，0．23±0．03，0．03±0．04，P〈0．05）。1、2周实验组较4、6周实验组及对照组心肌梗死范围明显减小[（20．75±2．63）％，（21．25±2．5）％，（27．25±1．71）％，（27．75±2．22）％，（26．50±0．71）％，（29．00±1．41）％，（27．00±1．41）％，（28．50±0．71）％，P〈0．05）]。结论犬急性心肌梗死早期冠状动脉旁路移植可以明显改善心肌室壁运动，唤醒更多的冬眠心肌，尤其2周内行冠状动脉旁路移植术可以最大限度地减少梗死心肌对室壁运动的影响，并可以减少心肌梗死范围。

Objective To investigate the effect of early coronary artery bypass grafting （CABG）to the left ventricular wall motion state and the significance of CABG to awake hibernating myocardial in dogs with acute myocardial infarction. Methods The anterior descending coronary of all thirty dogs were ligated into MI model. According to the operation date, the experimental groups included the 1 st week （ n = 6） , the 2nd week （ n = 4） , the 4th week （ n = 6） and the 6th week （ n = 6） CABG, and established control group （ n = 2 ） for every experimental group. Operators marked hibernate myocardial and determined the room wall motion score by means of dobutamine ultrasound load test （DSE） combining with tissue doppler imaging （DTI） technology before CABG and after eight weeks CABG through thoracotomy surgery for the experimental group and the control group. Every dog was executed and detected the area of MI. Results Four dogs of experimental group and all dogs of control group survived to the end of the study. The change of ventrieular room wall motion score in the 1st and the 2nd week CABG was smaller than that in the 4th and the 6th week CABG and MI group（0.03 ±0.06, 0.05±0.09, 0.23 ±0.08, 0.27 ±0.06, 0.32 ±0.05,P 〈0.05）.The change of room wall motion score in all CABG groups was smaller than that in MI group（ 1. 195 ±0.09, 1.25 ±0.18, 1.30 ±0.18, 1.36 ±0.11, 1.65 ±0.17,P 〈0.05）. The hibernate myocardial were more a- waken in all CABG groups than that in MI group （0.27 ± 0.12, 0.22 ± 0.04, 0.31 ± 0.09, 0.23 ± 0.03, 0. 03 ± 0. 04, P 〈 0.05 ）. The area of MI became smaller in 1 and 2 weeks CABG than that in 4 and 6 weeks CABG and MI group （20.75 ± 2.63, 21.25 ± 2.5, 27.25 ± 1.71, 27.75 ± 2.22, P 〈 0. 05）. Conclusions Early CABG surgery for dogs acute MI could improve the ventricular room wall motion obviously and wake up more hibernate myocardial. Especially, CABG surgery among two weeks could lessen the effect of MI to the ventricular room wall motion and reduce the scope of myocardial infarction maximatily.