Left circumflex artery
Main artery
Curves from the left main into the left atrioventricular groove beneath the left auricle, rounds the obtuse margin and ends on the posterior surface; in the 5 to 10% who are left dominant it continues to the crux and gives the posterior descending and AV nodal arteries.
Traced from the start
- Left (posterior) aortic sinus and left main stem
- Left circumflex artery
Detail
- Branches
- Obtuse marginals, left atrial branches, SA nodal in 40%, posterior descending and AV nodal when left dominant
- Supplies
- Lateral and posterior (inferobasal) LV wall, left atrium, part of the anterolateral papillary muscle
- Runs with
- Great cardiac vein in the left atrioventricular groove
When it goes wrong
Circumflex occlusion
Lateral STEMI in I, aVL, V5 and V6, or isolated posterior MI seen only as ST depression in V1 to V3
Circumflex occlusion with a standard 12-lead ECG
No ST elevation in about a third of cases, so a normal ECG does not exclude it; record V7 to V9
Practise this structure
1 question in the bank tagged Coronary Circulation.