ST elevation in leads II, III, and aVF localizes an infarct to which wall?

• A. Anterior wall
• B. Lateral wall
• C. Inferior wall
• D. Septal wall

Answer: (C)

ST elevation in the inferior leads indicates an infarction of the inferior wall of the left ventricle. Leads II, III, and aVF view the heart from the inferior aspect, so when a transmural infarct occurs there, the injury current raises the ST segment in these leads. This pattern specifically localizes the problem to the inferior wall. The anterior wall is seen in the precordial leads V1–V4, the lateral wall in I, aVL, V5–V6, and the septal wall in V1–V2, so elevations in those regions point to those walls. Clinically, inferior wall MI is commonly due to occlusion of the right coronary artery (especially in a right-dominant circulation), though left circumflex can supply the inferior region in left-dominant hearts.