= Circumflex artery
The \b[circumflex artery] is a major branch of the <left coronary artery> that follows the <coronary sulcus> around the left side of the <heart>. It gives branches including a <left marginal branch>.<Anatomy and Physiology 2e by J. Gordon Betts and others>[Section 19.1, left-coronary branches and Figure 19.15]{ref} It is distinct from the <left anterior descending artery>, the other typical major left-coronary branch.
Its route can also be relevant to posterior supply. When the <posterior descending artery> originates through the circumflex system, that connection contributes to a left-dominant <coronary dominance> pattern. A posterior branch name therefore does not uniquely identify a right-coronary origin.
The network distinction helps interpret where a finding lies. A segment before the left-coronary bifurcation is upstream of both major branches. A segment within the circumflex route is downstream of that split. These are different anatomical positions even though both may be described broadly as left-coronary findings.
An original two-outlet model assigns left-coronary flow $Q_L=Q_A+Q_C$, where $Q_A$ is anterior-branch flow and $Q_C$ circumflex flow. Knowing $Q_L=180\,\mathrm{mL\,min^{-1}}$ does not determine $Q_C$: pairs $(Q_A,Q_C)=(110,70)$ and $(90,90)$ produce the same total. An additional branch-sensitive observation is required.
Actual arterial mapping can be examined by selective contrast imaging. The primary Judkins method used selective catheterization with serial and cine recording.<Selective Coronary Arteriography: Part I: A Percutaneous Transfemoral Technic by Melvin P. Judkins>[Material and Technic]{ref} Such observation identifies a route and its geometry; interpreting <coronary blood flow> or oxygen supply also requires the relevant physiological measurements.
Back to article page
