ST elevations in leads V1, V2, V3 indicate occlusion of which vessel?

• A. Left Anterior Descending Artery
• B. Right Coronary Artery
• C. Left Circumflex Artery
• D. Posterior Descending Artery

Answer: (A)

ST elevations in the anterior chest leads point to injury of the anterior wall of the left ventricle, which is supplied predominantly by the left anterior descending artery. When the LAD is occluded, blood flow to the septal and anterior wall is compromised, manifesting as ST elevation in the anterior leads V1 through V3 (often extending to V4). The other arteries produce different patterns: right coronary artery occlusion tends to cause inferior changes in II, III, and aVF; left circumflex artery occlusion often causes lateral changes in I, aVL, V5–V6; a posterior MI typically shows ST depression in the anterior leads with reciprocal ST elevation in posterior leads. Therefore, ST elevations in V1–V3 most strongly indicate LAD occlusion.