What is the significance of the left anterior descending artery (LAD) in myocardial infarction?

• A. It supplies blood to the anterior wall of the heart and is commonly affected in anterior MIs
• B. It supplies blood to the posterior wall of the heart
• C. It supplies the inferior wall of the heart
• D. It supplies the right ventricle

Answer: (C)

The main point is that the left anterior descending artery nourishes the anterior wall of the left ventricle and most of the interventricular septum. Because it supplies a large, high‑risk portion of the heart muscle, occlusion of the LAD—especially proximally—causes a large anterior (and often septal) myocardial infarction. This leads to significant loss of contractile function, potential heart failure, and a higher risk of life‑threatening arrhythmias. Clinically, anterior MI is flagged by ST elevations in the front chest leads (V1–V4) and can be particularly dangerous, which is why LAD infarctions are viewed with great concern and urgency. The inferior wall is typically supplied by the right coronary artery (in most people) or the left circumflex in left‑dominant hearts, and the right ventricle is mainly supplied by the RCA, so those regions are not primarily fed by the LAD.