Sinoatrial nodal artery

Last revised by Yuranga Weerakkody on 12 Feb 2022

The sinoatrial (SA) nodal artery is the small artery that supplies the sinoatrial (SA) node of the heart (the pacemaker). 

Gross anatomy


Right coronary artery in 60% of cases and the left coronary artery in 40% of cases.


The artery turns posteriorly below the superior vena caval opening.

Variant anatomy

The SA node can arise from its own opening in the anterior aortic sinus. 

A study of 516 SA nodal arteries using MDCT found 96.4% of arteries were single whilst 3.6% were double. In this study only 53.4% of SA nodal arteries originated from the right coronary artery with 43% originating from the left circumflex artery

Other variants include

  • S-shaped variant 4

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Cases and figures

  • Case 1: normal coronary angiogram (DSA)
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  • Case 2: normal CTCA
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  • Case 3
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