Effects of Acute Myocardial Ischaemia on Platelet Aggregation in the Coronary Sinus and Aorta in Dogs

Abstract

Effect of an acute myocardial ischemia on circulating platelet aggregates (CPA) in the coronary sinus and aorta was studied in open chest dogs. Even before induction of myocardial ischemia, significantly more CPA were found in the coronary sinus than in the aorta. Acute myocardial ischemia produced by a non-thrombotic coronary artery occlusion increased CPA in coronary sinus but not in the aorta. Administration of acetylsalicylic acid (ASA) reduced extent of myocardial ischemia as evidenced by reduced ST-segment elevations in the epicardial ECG. Before induction of myocardial ischemia, ASA significantly reduced CPA in the coronary sinus, but no significant effect was observed during myocardial ischemia. No effect of ASA on CPA was found in the aorta.