Objective:To investigate the protective effects of thoracic epidural anesthesia on myocardial infarction by observing the hemodynamics

cardial function and the size of infarcted area.Methods:Thirty-two rabbits were anesthetized with 20% urethane (1.0g/kg

i.v.).Following treacheal intubation

epidural catheter was put into at T 6～7 with the anterior end of the catheter reaching at T 2～3

and femoral artery was cannulated for determination of MAP.Cardiac catheter was placed via left carotid artery.After the epidural anesthesia was made sure to be effective

the anterior descending branches of left coronary artery (LAD) were ligated and myocardial infarction was confirmed by ST elevation>0.1 mv.The rabbits were randomly divided into two groups(n=16):group I was the control;in group Ⅱ

1% lidocaine 2～3 mg/kg was infused to epidural space.Hemodynamics such as MAP

HR

left ventricular systolic pressure(LVSP)

left ventricular end-diastolic pressure(LVEDP) and ±dp/dt max were monitored pre- and 30min post-ligation.The extent of infarct area was determined by TTC staining.Results:After ligation

LVEDP increased and LVSP、±dp/dt max decreased in the control group.TEA significantly repressed the increasing of LVEDP and the decreasing of LVSP

±dp/dt max caused by LAD ligation.TEA could reduce the size of infarcted area while there was no significant difference in 4h

8h after ligation.Conclusion:TEA can significantly protect myocardium from injury in rabbits with experimental myocardial infarction.