2009 年 30 巻 2 号 p. 88-94
The effects of sevoflurane on myocardial ischemia and reperfusion injury have not been well studied, especially in in vivo model. The present study aimed to investigate the effect of timing and duration of sevoflurane exposure on the intensity of myocardial response, and ischemia/reperfusion arrhythmias.
All anesthetized open-chest rabbits underwent 30 min of left anterior descending coronary artery(LAD) occlusion followed by 3 hrs of reperfusion. In the control group(C), and sevoflurane group(S), rabbits were subjected to 30 min of LAD occlusion and 3 hrs of reperfusion under ketamine/xylazine(k/x) or sevoflurane anesthesia respectively. The ischemia-preconditioned rabbits underwent 5 min of LAD occlusion followed by 10 min of reperfusion under k/x anesthesia(C-IP), or sevoflurane(S-IP). In the sevoflurane-preconditioned group(C-SP), 30 min of sevoflurane exposure at a 1.5% end-tidal concentration was followed by 15 min of washout before 30 min of LAD occlusion and 3 hrs of reperfusion under k/x anesthesia. At the end of 3-hrs reperfusion period, area at risk was delineated by Evans blue and infarct size determined by triphenyltetrazolium chloride(TTC) staining. The rate pressure product did not alter significantly at any point among all the groups. Compared with group C, myocardial protective effect was observed in groups of S, C-IP, S-IP and C-SP. However, infarct size in sevoflurane-preconditioned group was significantly larger than those of S and S-IP groups. Also, infarct limiting effect of S-IP group was significantly intensified compared with C-IP and S. Continuous exposure of sevoflurane reduced arrhythmias during not only ischemia but reperfusion period in rabbit hearts.
These results suggested that continuous sevoflurane exposure might confer additive infarct limiting effect on ischemic preconditioning. We found that ischemic preconditioning and sevoflurane preconditioning do not have anti-arrhythmic effect, though sevoflurane exposure has anti-arrhythmic effects against ischemia and reperfusion-induced arrhythmia.
