Failure of Free Fatty Acids to Influence Degree of Myocardial Injury Following Acute Coronary Artery Occlusion in Pigs

Abstract

Elevation of circulating free fatty acids (FFA) has been implicated as a deleterious influence during conditions of myocardial ischemia. To further explore this question, acute coronary artery occlusion was produced in closed-chest, anesthetized pigs. FFA levels were elevated by injecting heparin and then infusing a lipid emulsion at 1 or 2 h following occlusion. Precordial ECG mapping was used to assess the degree of myocardial injury. At both 1 and 2 h following occlusion the lipid infusion elevated the mean FFA level to over 2,500 muM. ST segment levels failed to indicate any concomitant increase in degree of myocardial injury. By contrast, an isoproterenol infusion (30 min, 4-8 mug/min) under similar conditions did result in ST segment changes suggestive of extended myocardial injury. Augmented arterial FFA levels do not influence the degree of myocardial injury following acute coronary artery occlusion.