The left circumflex artery supplies which myocardial regions?

• A. Lateral segments (and sometimes apex)
• B. Anterior segments
• C. Inferior segments
• D. Basal septal segments

Answer: (A)

The left circumflex artery mainly perfuses the lateral wall of the left ventricle through its obtuse marginal branches. In some hearts, particularly with left-d dominant circulation, these branches can extend toward the apex, so the apex may receive blood from the LCX as well. The anterior wall and septum are supplied mainly by the LAD, while the inferior wall is typically supplied by the RCA (in right-dominant circulation) or LCX via the PDA in left-dominant hearts. So the LCX’s territory is the lateral segments, and it can reach the apex in some individuals.