Reduction of postischemic contractile dysfunction of the isolated rat heart by sevoflurane: Comparison with halothane

Our aims were to evaluate the effect of sevoflurane on postcardioplegic fun ctional recovery of the isolated rat heart including the role of the adenos ine triphosphate regulated potassium (K-ATP) channels and to compare the ca rdioprotective effects of equipotent concentrations of halothane and sevofl urane. Isolated perfused rat hearts were subjected to 45 or 60 min normothe rmic cardioplegic arrest and 30 min reperfusion. Sevoflurane (0.9% and 1.7% ), halothane (0.4% and 0.8%), or sevoflurane (0.9%) plus glibenclamide (10 mu M) (a K-ATP channel blocker) were administered at different time interva ls. Measurements of mechanical activity were made before and after arrest. Function during reperfusion after cardioplegic arrest was significantly dep ressed in both untreated and treated hearts. However, sevoflurane administe red both before and after arrest, or before only, significantly improved fu nctional recovery after 45 min of cardioplegia. This protective effect was abolished by simultaneous administration of glibenclamide, suggesting a rol e of the K-ATP channel. Sevoflurane was as effective as halothane in improv ing postcardioplegic functional performance. After 45 min of arrest, hearts exposed to either anesthetic at both concentrations had a significantly hi gher work performance on discontinuation of their administration than untre ated controls. After 60 min of arrest, neither anesthetic elicited protecti on.