Sinoatrial nodal artery

The sinoatrial nodal artery (or sinuatrial nodal artery or sinoatrial artery) is an artery of the heart which supplies the sinoatrial node, the natural pacemaker center of the heart, and arises from the right coronary artery in around 60% of people. In about 40% of cases, the sinoatrial artery is a branch of the left circumflex coronary artery.[1] In less than 1% of humans, the artery has an anomalous origin directly from the coronary sinus, descending aorta, or distal right coronary artery.

Sinoatrial nodal artery
Low magnification micrograph of a sinoatrial node (central on image), surrounding the sinuatrial nodal artery (on lumen in the image). H&E stain.
RCA = right coronary
AB = atrial branches
SANB = sinuatrial nodal
RMA = right marginal
LCA = left coronary
CB = circumflex branch
LAD/AIB = anterior interventricular
LMA = left marginal
PIA/PDA = posterior descending
MARG = left marginal
AVN = atrioventricular nodal

SCV = small cardiac
ACV = anterior cardiac
AIV/GCV = great cardiac
MCV = middle cardiac
CS = coronary sinus
LatinRamus nodi sinuatrialis arteriae coronariae dextrae
Anatomical terminology

In more than 50% of human hearts, the artery actually courses close to the superior posterior aspect of the interatrial septum.[2] The origin of the sinoatrial node artery is not related to coronary artery dominance, which means the side (right or left) that provides the circulation to the back of the heart. In contrast, the atrioventricular nodal branch, that is the artery that brings blood to the atrioventricular node, depends on coronary artery dominance.

The sinoatrial node surrounds the sinoatrial artery, which can run centrally (in 70% of individuals) or off center within the node.[3]

A left S-shaped sinoatrial artery, originating from the proximal left circumflex or LCx artery, has been described as a common variant in approximately 10% of human hearts.[4] This artery is larger than normal and supplies a good part of the left atrium, but also right sided structures like part of the sinoatrial node and the atrioventricular nodal areas. In this variant, the artery courses in the sulcus between the left superior pulmonary vein and the left atrial appendage where it could be susceptible to injury during catheter or surgical ablation procedures on the left atrium, especially for atrial fibrillation ablation or open heart cardiac surgery.

Additional images


  1. Pejković B, Krajnc I, Anderhuber F, Kosutić D (July 2008). "Anatomical aspects of the arterial blood supply to the sinoatrial and atrioventricular nodes of the human heart". Journal of International Medical Research. 36 (4): 691–8. doi:10.1177/147323000803600410. PMID 18652764.
  2. Click RL, Holmes DR Jr, Vliestra RE et al. Anomalous coronary arteries: Location, degree of atherosclerosis and effect on survival-A report from the coronary artery surgery study. J Am Coll Cardiol 1989; 13:531-537.
  3. Sanchez-Quintana D, Anderson RH, Cabrera JA, et al. The terminal crest: morphological features relevant to electrophysiology. Heart 2002;88: 406–411.
  4. Saremi F, Channual S, Abolhoda A et al. MDCT of the S-shaped sinoatrial node artery. Am J Roentgenol 2008; 190:1569-1575.
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