Atrioventricular nodal artery

Branch

A small branch given off by the dominant artery at the crux, so from the RCA in about 90% and the circumflex in 10%; it passes forward to the AV node and the proximal bundle of His.

Traced from the start

  1. Right (anterior) aortic sinus
  2. Left (posterior) aortic sinus and left main stem
  3. Right coronary arteryLeft circumflex artery
  4. Atrioventricular nodal artery

Detail

Origin
Dominant artery at the crux: RCA 90%, circumflex 10%
Supplies
AV node and proximal His bundle

When it goes wrong

RCA occlusion proximal to the AV nodal branch

Second- or third-degree AV block in up to 20% of inferior MIs; block is in the node, so the escape is narrow-complex at 40 to 60/min, usually transient and atropine-responsive

Practise this structure

1 question in the bank tagged Atrioventricular Node.