Hara Tetsuya
Department of Anesthesia, Nagasaki University Hospital, Nagasaki 852-8501.
Masui. 2006 May;55(5):552-9.
Perioperative myocardial ischemia is one of the most important complications associated with significant risk of perioperative cardiac event. Ischemic preconditioning is a phenomenon in which single or multiple brief periods of ischemia have been shown to protect the myocardium against a more prolonged ischemic insult, the result of which is a marked reduction in myocardial infarct size, severity of myocardial stunning, or incidence of cardiac arrhythmias. Myocardial stunning is a clinically important ischemia-reperfusion injury described as a prolonged postischemic contractile dysfunction of myocardium salvaged by reperfusion. Experimental data indicate that general anesthetics protect the myocardium against ischemia-reperfusion injury, as shown by decreased infarct size and a more rapid recovery of contractile function on myocardial stunning. This phenomenon is called anesthetic preconditioning. Volatile anesthetics and morphine have a strong preconditioning like effect. The cardioprotective effect of volatile anesthetics has been supported by some clinical studies. Although the cellular mechanism of anesthetic preconditioning is not fully investigated, possible mechanism involves adenosine, adenosine receptors, the ATP-dependent potassium (K(ATP)) channels, protein kinase C, reactive oxygen species and other mediators or substances. Further, mitochondrial K(ATP) channels play the central role in anesthetic preconditioning.
围手术期心肌缺血是与围手术期心脏事件重大风险相关的最重要并发症之一。缺血预处理是一种现象，其中单次或多次短暂缺血已被证明可保护心肌免受更长时间的缺血性损伤，其结果是心肌梗死面积显著减小、心肌顿抑严重程度降低或心律失常发生率降低。心肌顿抑是一种临床上重要的缺血再灌注损伤，被描述为经再灌注挽救的心肌缺血后收缩功能障碍的延长。实验数据表明，全身麻醉药可保护心肌免受缺血再灌注损伤，表现为梗死面积减小以及心肌顿抑时收缩功能恢复更快。这种现象称为麻醉预处理。挥发性麻醉药和吗啡具有很强的类似预处理的作用。一些临床研究支持了挥发性麻醉药的心脏保护作用。尽管麻醉预处理的细胞机制尚未完全研究清楚，但可能的机制涉及腺苷、腺苷受体、ATP依赖性钾（K(ATP)）通道、蛋白激酶C、活性氧以及其他介质或物质。此外，线粒体K(ATP)通道在麻醉预处理中起核心作用。
