[Activation of hemostasis and perioperative ischemia].

The prevention of perioperative myocardial ischemia is one of the cornerstones of anesthetic techniques. From the perspective of anesthesiologists, the traditional relation between oxygen supply and demand is improved mainly by reducing demand. Cardiologists, however, look at the problem from the other side of the equation. For the cardiologist, myocardial infarction is an entirely thrombotic event caused by changes in procoagulants, regardless of increased demand for oxygen. It is conceivable that signs of perioperative myocardial ischemia, which are related to increased oxygen demand, are equivalent to stable angina. Rarely do they cause myocardial infarction. However, transient occlusion or embolization from an unstable plaque can cause ischemia unrelated to increased demand. Cardiac morbidity during the perioperative period is insufficiently explained by the traditional concept of increased myocardial oxygen demand during surgery. On the contrary, evidence suggests that infarction depends on changes in oxygen supply secondary to transient or permanent episodes of thrombotic vascular occlusion. Our data suggest that these thrombotic events are dependent on hypercoagulability. It may be that anesthesiologists should focus on preventing rupture of the atherosclerotic plaque or on examining changes in coagulation, given that such events might facilitate the appearance of thrombosis in coronary arteries with unstable plaques.