FAILURE OF HIGH CONCENTRATIONS OF CIRCULATING FREE FATTY ACIDS TO PROVOKE ARRHYTHMIAS IN EXPERIMENTAL MYOCARDIAL INFARCTION

The hypothesis that high circulating free-fatty-acid (F.F.A.) concentrations may be arrhythmogenic to the ischæmic myocardium has important implications for the treatment of patients with acute myocardial infarction. Direct evidence for this hypothesis has been obtained by other workers using the ischæmic dog-heart preparation. The possible arrhythmogenic effect of high plasma-F.F.A. concentrations has now been re-examined in experimental occlusion of the anterior descending coronary artery (or one of its branches) in 30 dogs. In no case was it clear that high plasma-F.F.A. concentrations by themselves provoked or exaggerated ectopic activity, even though the site and size of arterial ligations, multiple ligations, and adrenaline infusion were designed to lead to arrhythmias. However, when combined with adrenaline infusion, elevation of plasma-F.F.A. concentrations provoked ectopic activity in 3 of 4 dogs. Of all 30 dogs, ventricular tachycardia occurred in only 2 and ventricular fibrillation in another 2. These results argue against a major role for high plasma-F.F.A. concentrations in the genesis of serious arrhythmias after coronary-artery occlusion. © 1971.