Triggering of acute myocardial infarction.

The mechanisms of acute coronary artery disease onset are receiving increasing attention. Study of these mechanisms has been stimulated by the finding that the onset of acute myocardial infarction is more likely during the morning hours after awakening, suggesting that activities of the patient often trigger the event. Triggering may occur when stressors placed on the body produce hemodynamic, vasoconstrictive, and prothrombotic forces-acute risk factors-that can cause disruption of a vulnerable atherosclerotic plaque leading to thrombosis. Insight into triggering and plaque vulnerability may lead to a new approach in the prevention of acute myocardial infarction.