The left coronary artery supplies which walls of the left ventricle?

• A. Anterior, Posterior and Lateral walls
• B. Right ventricular wall
• C. Interventricular septum only
• D. Pulmonary arteries

Answer: (A)

Understanding coronary blood supply helps explain which LV walls get fed by the left coronary artery. The left coronary artery branches into the left anterior descending (LAD) and the left circumflex (LCx). The LAD runs along the anterior interventricular groove and supplies the anterior wall of the left ventricle (and much of the anterior septum). The LCx travels in the left atrioventricular groove and supplies the lateral wall of the left ventricle. The posterior wall’s perfusion depends on coronary dominance: in left-dominant hearts, branches from the left coronary system can feed the posterior wall, while in right-dominant hearts the posterior wall is typically supplied by a branch from the right coronary artery. Putting it together, the left coronary artery can supply the anterior, lateral, and, in certain anatomies, the posterior walls of the left ventricle. The other options don’t align with how the left coronary system distributes blood: the right ventricular wall is mainly supplied by the right coronary artery, the interventricular septum is predominantly fed by the LAD, and the pulmonary arteries aren’t supplied by coronary arteries.