sinuatrial nodal artery (heart, anatomy)
Last reviewed 01/2018
The sinuatrial nodal artery may arise as a branch of one or both of two larger arteries:
- the right coronary artery:
- present in 55% of the population
- originates proximally in the course of the right coronary artery just after it has emerged from the right coronary sinus
- the circumflex branch of the left coronary artery:
- present in 45% of the population
- originates just after the circumflex artery has diverged from the left coronary artery
- passes superiorly and to the right, posterior to the aorta and superior to the upper, left pulmonary vein
Often, the artery forms an arterial ring around the structures it supplies:
- right atrium
- right auricle
- sinuatrial node
Rarely, the sinuatrial artery may arise directly from the right coronary sinus separately from the right coronary artery.