[Cardioprotection by anesthetics].

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.