What is the expected EKG pattern when a thrombus in a coronary artery lodges permanently in the vessel?

When a thrombus lodges permanently in a coronary artery, it typically leads to a myocardial infarction (MI), which is characterized by specific changes in the electrocardiogram (EKG). The expected EKG pattern in this scenario includes ST elevation, which indicates that there is an active myocardial injury occurring as a result of prolonged ischemia due to insufficient blood flow to the heart muscle.

ST elevation signifies that a significant portion of the heart muscle is affected, often resulting from the complete blockage of a coronary artery. This elevation occurs because the damaged cardiac muscle cells become depolarized due to the lack of oxygen, fundamentally altering the electrical activity that is reflected in the EKG tracing. The presence of ST elevation is classically associated with ST-Elevation Myocardial Infarction (STEMI), denoting a more serious condition that requires immediate medical intervention for restoration of blood flow to avert further myocardial damage.

In contrast, the other EKG patterns are associated with different conditions or less severe stages of cardiac ischemia. For instance, ST depression is typically indicative of subendocardial ischemia or angina rather than a full-thickness myocardial infarction. Non-ST elevation can suggest unstable angina or non-ST elevation myocardial infarction (