Mild Myocardial Stunning Affects Platelet Aggregation and Certain Hemostatic Factors in Swine

Summary: Myocardial stunning is characterized by transient contractile dysfunction occurring subsequent to an episode of ischemia followed by reperfusion. Platelet activation and he-mostatic abnormalities have been described in patients with unstable angina and acute myocardial infarction, however, their role in the pathogenesis of myocardial stunning is unknown. The purpose of this study was to determine if platelet aggre-gation and certain hemostatic factors change during myocardial stunning following brief coronary arterial occlusion. Nine Yorkshire swine underwent left anterior descending coronary artery occlusion for 8 minutes followed by 90 minutes of reper-fusion. Blood samples were obtained at baseline, at 4 and 8 minutes of occlusion, and at 60 and 90 minutes of reperfusion. Platelet aggregability and concentrations of antithrombin III, protein C, protein S, fibronectin, endothelin 1, and the stabl