How is NSTEMI distinguished from STEMI?

How is NSTEMI distinguished from STEMI?

• A. ST segment elevation on ECG
• B. Troponin level greater than threshold
• C. Chest pain duration
• D. Blood pressure

Answer: (A)

The key feature that separates STEMI from NSTEMI is what shows up on the ECG. STEMI produces new ST-segment elevation in the leads that correspond to the affected area of the heart, reflecting a full-thickness (transmural) infarct from a complete occlusion. NSTEMI, on the other hand, does not show ST-segment elevation; it usually has other ECG changes such as ST depression or T-wave inversion, even though troponin is elevated and indicates myocardial injury. Troponin levels confirm an MI in both conditions, so they don’t distinguish between STEMI and NSTEMI. Chest pain duration and blood pressure aren’t reliable discriminators for the type of myocardial infarction.

The key feature that separates STEMI from NSTEMI is what shows up on the ECG. STEMI produces new ST-segment elevation in the leads that correspond to the affected area of the heart, reflecting a full-thickness (transmural) infarct from a complete occlusion. NSTEMI, on the other hand, does not show ST-segment elevation; it usually has other ECG changes such as ST depression or T-wave inversion, even though troponin is elevated and indicates myocardial injury. Troponin levels confirm an MI in both conditions, so they don’t distinguish between STEMI and NSTEMI. Chest pain duration and blood pressure aren’t reliable discriminators for the type of myocardial infarction.