What characterizes an ST elevated myocardial infarction (STEMI)?

An ST elevated myocardial infarction (STEMI) is characterized by a full thickness infarct with complete blockage of a coronary artery. This type of myocardial infarction occurs when there is a significant blockage, often due to a thrombus (blood clot) formed on a ruptured atherosclerotic plaque, which prevents blood flow through the artery. As a result of this complete blockage, the myocardium (heart muscle) supplied by that artery becomes ischemic and can suffer damage, leading to necrosis (death of the heart tissue).

The presence of ST elevation on an electrocardiogram (ECG) is indicative of this type of infarction, as it demonstrates that there is ongoing myocardial injury. The extent of the damage can involve the entire thickness of the heart muscle wall (transmural infarction), which has significant implications for treatment and prognosis. Prompt recognition and intervention are crucial to restore blood flow, minimize heart damage, and reduce complications associated with a STEMI.