A coronary angiogram shows that the posterior interventricular (posterior descending) artery arises from the left circumflex artery. How should this coronary circulation be classified?

• A Left dominant ✓
• B Right dominant
• C Codominant (balanced)
• D Normal right-dominant pattern

Explanation

Coronary dominance is defined by which artery gives rise to the posterior interventricular artery. In about 85 percent of people it arises from the right coronary artery (right dominant). When it arises from the left circumflex, as here, the circulation is left dominant, seen in roughly 8 percent. B balanced pattern means both the right coronary and circumflex give posterior interventricular branches reaching toward the crux, so neither single origin applies.

Reference: Gray's Anatomy for Students, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.