RESUMO
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 ventricular 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 ±40.06,0.32 ±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 awaken 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.