ST-segment elevation criteria for STEMI include?

• A. ST depression thresholds
• B. ≥1 mm in two contiguous limb leads or ≥2 mm in two contiguous precordial leads
• C. ≥3 mm in all leads
• D. Elevation in only one lead

Answer: (B)

ST-segment elevation signaling STEMI is identified when the ST segment rises at the J point in leads that view the same region of the heart, and this elevation is present in adjacent leads that cover the same territory. This pattern indicates transmural ischemia in that myocardial region and points to an acute infarction needing urgent reperfusion. The emphasis is on elevation appearing in more than one neighboring lead that corresponds to a single area of the heart, not in a single isolated lead. ST depression reflects ischemia without full-thickness injury, and elevation in only one lead can be an artifact or a non-STEMI pattern, so they do not meet the STEMI criteria.