Which statement best differentiates STEMI from NSTEMI on telemetry?

• A. STEMI shows ST elevation in contiguous leads; NSTEMI shows ST depression or T-wave changes without ST elevation
• B. NSTEMI shows ST elevation
• C. STEMI shows Q waves only
• D. NSTEMI shows inverted P waves

Answer: (A)

On telemetry, the key difference between STEMI and NSTEMI is the ST segment pattern. ST-segment elevation in two or more contiguous leads indicates STEMI, reflecting a full-thickness (transmural) myocardial injury from an acute occlusion. NSTEMI, by contrast, does not show ST-segment elevation; instead you commonly see ST-segment depression or T-wave inversion, which signal subendocardial ischemia. The idea of “contiguous leads” matters because elevations in leads that view the same region of the heart confirm a real ischemic event in that territory. This distinction guides urgent management, with STEMI requiring emergent reperfusion, while NSTEMI is treated with anti-ischemic strategies and risk assessment without immediate reperfusion.