Which coronary vessel is commonly referred to as the primary supplier to the left ventricle?

• A. Circumflex artery
• B. Left anterior descending artery (LAD)
• C. Right coronary artery
• D. Posterior descending artery

Answer: (B)

The left anterior descending artery is the main supplier to the left ventricle. It runs along the anterior interventricular sulcus and provides the majority of the blood to the anterior wall of the left ventricle and to most of the interventricular septum through its septal perforators, with diagonal branches nourishing the anterior LV as well. Because so much LV muscle depends on it, occlusion here often causes a large anterior-wall heart attack (the classic “widowmaker” scenario).

The circumflex artery mainly nourishes the lateral wall of the left ventricle and, in some hearts, parts of the posterior wall, but it is not the primary LV supplier. The right coronary artery supplies the right heart and, depending on coronary dominance, can contribute to the inferior/posterior left ventricle, but again, it is not the principal source for the LV. The posterior descending artery supplies the posterior interventricular septum and diaphragmatic surface in specific dominance patterns, not the primary LV mass.