Pharmacological salvage of myocardium

During the past decade, efforts to limit the extent of myocardium exhibiting infarction once ischemia has been initiated have focused on manipulation of myocardial oxygen supply and demand as well as the process of injury itself. Interventions of promise range from the conventional, moderate increase in inspired oxygen content, to administration of hyaluronidase or intracoronary thrombolysis to augment oxygen supply; use of beta-adrenergic blocking drugs and nitroglycerin to diminish demand; and administration of calcium antagonists and prostaglandin synthesis inhibitors to limit the injury process. The ultimate effects on infarct size and long-term mortality have yet to be established unequivocally for any of these approaches in the clinical setting of acute myocardial infarction, but significant preservation of ischemic myocardium with hypothermia and with administration of nifedipine during coronary-artery bypass surgery have been documented. Several prospective, large-scale, blinded, and random sample selection clinical trials are currently in progress. Their results should definitively elucidate the clinical utility of specific interventions under defined conditions and should help to further improve the management of patients with ischemic heart disease.