Myocardial ischaemic/ reperfusion injury in the anaesthetized rabbit: comparative effects of halothane and isoflurane

The effects of halothane and isoflurane anaesthesia on myocardial injury in rabbits subjected to coronary artery ligation and subsequent reperfusion were analyzed. Although halothane and isoflurane (at inspired concentrations of 1.0 and 1.5 per cent, respectively) exerted comparable effects on cardiovascular status during ischaemic and reperfusion phases, greater preservation of subcellular integrity (as assessed by mitochondrial and sarcoplasmic reticular ATPase activities and myocardial ionic alterations) and a lower incidence of ventricular fibrillation and severe hypotension occurred with halothane. Our results indicate that in studies of experimental myocardial ischaemia anaesthetics may, independently of cardiovascular actions, influence the nature and extent of resulting injury, possibly by virtue of their differing effects on subcellular membrane systems.