Ischaemic periods which lust only several minutes can result in a reversible reduction in cardiac contractility known as cardiac stunning. This is a potentially dangerous condition since arrhythmias and left ventricular failure are common in the stunned heart. The anaesthetics fentanyl, halothane and isoflurane have been shown to improve recovery from cardiac stunning (1,2). In this project the electrophysiological effects of these anaesthetics on guinea-pig isolated ventricular myocytes were investigated to determine the mechanisms underlying their cardioprotective effect.