As a cardiac specialist with extensive experience in diagnosing and treating heart conditions, I can explain the differences between a STEMI and a non-STEMI. A STEMI, which stands for ST-elevation myocardial infarction, is a type of heart attack that occurs when a coronary artery is completely blocked by a blood clot. This blockage leads to a significant amount of heart muscle dying, which is why it's considered a medical emergency requiring immediate treatment. The "ST-elevation" in the name refers to a specific pattern seen on an electrocardiogram (ECG) that indicates the presence of this type of heart attack. On the other hand, a non-STEMI, also known as a non-ST-segment elevation myocardial infarction, is a heart attack that happens when there is a severe narrowing of a coronary artery, but the artery is not completely blocked. This means that some blood flow is still possible, although it's reduced. The damage to the heart muscle is generally less severe than in a STEMI, and the symptoms may be less dramatic. The ECG pattern for a non-STEMI does not show the same ST-segment elevation as in a STEMI. Both conditions require medical attention, but the urgency and treatment approach can differ based on the type of heart attack. read more >>

A STEMI or ST-elevation myocardial infarction is caused by a sudden complete (100%) blockage of a heart artery (coronary artery). A non-STEMI is usually caused by a severely narrowed artery but the artery is usually not completely blocked. The diagnosis is initially made by an electrocardiogram (ECG or EKG).read more >>