Electrocardiographic (ECG) signs of acute myocardial ischemia were observed to improve following induction of anesthesia in 28 of 32 patients with impending myocardial infarction who were about to undergo emergency coronary artery surgery. The ECG signs of ischemia improved after induction of anesthesia and controlled ventilation with enriched oxygen (02) mixtures. Moreover, cardiac irritability was much decreased in those patients with cardiac arrhythmias prior to induction of anesthesia. The authors attribute this to many factors, among which are increased availability of O2 to the myocardium, decreased afterload, and reduced cardiac work. When pain and anxiety are relieved by anesthesia, catecholamine release, with all its untoward effects, will be decreased.