Vik-Mo H, Ottesen S, Renck H
Scand J Clin Lab Invest. 1978 Dec;38(8):737-46. doi: 10.1080/00365517809104881.
The effects of thoracic epidural analgesia (TEA) on myocardial performance and metabolism and on the severity of an acute myocardial ischaemia, were studied in eight anesthetized open-chest dogs. TEA reduced mean arterial blood pressure (AP) by 26%, heart rate (HR) by 20%, left ventricular dP/dt by 37%, and myocardial oxygen consumption by 27%. Although arterial concentrations of free fatty acids, glucose and lactate were unchanged, their myocardial uptake was reduced in proportion to the reduction in mechanical activity of the heart. Acute ischaemic injury was estimated from epicardial ECG recordings 10 min after occlusion of a branch of the left anterior descending coronary artery. In seven of eight dogs TEA caused a substantial reduction in the severity of the acute myocardial ischaemic injury. In the eight dogs investigated, the sum of ST segment elevations in epicardial ECG recordings was reduced from 34.0 +/- 3.4 to 23.3 +/- 2.8 mV (mean +/- SEM, P less than 0.01). After restoration of AP and HR to control values with phenylephrine and atrial pacing, the favourable effect of TEA on myocardial ischaemic injury was abolished. It is concluded that TEA effected a reduction in the severity of myocardial ischaemia in open-chest dogs, mainly through reduction of myocardial mechanical activity with consequent reduction of myocardial metabolism.
在八只麻醉开胸犬中研究了胸段硬膜外镇痛（TEA）对心肌性能和代谢以及急性心肌缺血严重程度的影响。TEA使平均动脉血压（AP）降低26%，心率（HR）降低20%，左心室dP/dt降低37%，心肌耗氧量降低27%。尽管动脉血中游离脂肪酸、葡萄糖和乳酸的浓度未变，但它们的心肌摄取量与心脏机械活动的降低成比例减少。在左前降支冠状动脉分支闭塞10分钟后，根据心外膜心电图记录评估急性缺血损伤。在八只犬中的七只，TEA使急性心肌缺血损伤的严重程度大幅降低。在所研究的八只犬中，心外膜心电图记录中ST段抬高总和从34.0±3.4降低至23.3±2.8mV（平均值±标准误，P<0.01）。在用去氧肾上腺素和心房起搏使AP和HR恢复至对照值后，TEA对心肌缺血损伤的有利作用消失。得出的结论是，TEA使开胸犬心肌缺血的严重程度降低，主要是通过降低心肌机械活动从而降低心肌代谢来实现的。
