Reading: Sinoatrial Nodal Artery Arising from the Right Posterolateral Artery: A Rare Anatomical Variant

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Sinoatrial Nodal Artery Arising from the Right Posterolateral Artery: A Rare Anatomical Variant



We discuss a case report of a 66-year-old male with no prior cardiac history who presented to the hospital with persistent hiccups and shortness of breath. Following a positive nuclear stress test and cardiac catheterization, a rare anatomical variant of a sinoatrial nodal artery originating from the right posterolateral artery was revealed.


Coronary vesselsAnatomical variationCoronary circulationNSTEMI
  • Year: 2022
  • Volume: 18 Issue: 4
  • Page/Article: 86-88
  • DOI: 10.14797/mdcvj.1109
  • Submitted on 20 Mar 2022
  • Accepted on 1 Aug 2022
  • Published on 6 Sep 2022
  • Peer Reviewed

A 66-year-old male with no prior cardiac history presented to the hospital with persistent hiccups, causing shortness of breath. A nuclear stress test showed a fixed perfusion defect involving the inferior wall, possibly due to diaphragmatic attenuation artifact with no evidence of stress-induced myocardial ischemia, and a mildly decreased left ventricular ejection fraction of 44% (Figure 1). Coronary angiography revealed two-vessel coronary artery disease, 80% stenosis of the middle right coronary artery (RCA), diffuse heavy calcification of the left anterior descending artery (LAD) involving the proximal and mid-portions with 80% maximal stenosis, a small caliber left marginal, and a sinoatrial (SA) nodal branch originating from the right posterolateral artery (RPLA) (Figure 2 A, B).

Figure 1 

Nuclear stress test showing fixed perfusion defect in the inferior wall possibly due to diaphragmatic motion artifact.

Figure 2 

(A, B) Coronary artery angiography left anterior oblique view of the SA nodal artery arising from the right posterolateral artery. SA: sinoatrial

The SA nodal artery, a branch of the main coronary arteries, supplies blood to the SA node. The SA node is also known as the natural pacemaker of the heart. In 60% to 70% of cases, its blood supply originates from the RCA, and in 20% to 30% from the LAD and left circumflex coronary artery (LCX). The SA nodal artery provides vital oxygen and nutrients to the SA node, which is a key component in heart contraction that originates the initial electrical signal for atrial contraction.1 When originating from the RCA, the SA nodal artery most frequently arises at a mean distance of 1.2 cm (range 0.2–2.2 cm) from its beginning.2 In less than 1% of cases, the artery originates from the distal RCA.3 The posterolateral artery, also known as the posterior left ventricular artery, arises from the RCA in a typical dominant circulation. It is a terminal branch that supplies the inferior portion of the heart along with the posterior descending artery (PDA). It can also arise from the LAD or LCX.4 Based on available data, this the first documented case of an SA nodal artery originating from the RPLA.

Competing interests

The authors have no competing interests to declare.


  1. StatPearls [Internet]. Bethesda, MD: National Library of Medicine; c2022. Nordick K, Tedder BL, Zemaitis MR. Anatomy, Thorax, Sinoatrial Nodal Artery; 2021 Jul [cited 2022 Aug 14]. Available from: 

  2. Pejkovic B, Krajnc I, Anderhuber F, Kosutic D. Anatomical aspects of the arterial blood supply to the sinoatrial and atrioventricular nodes of the human heart. J Int Med Res. Jul-Aug 2008;36(4):691–8. doi: 

  3. Saremi F, Channual S, Abolhoda A, et al. MDCT of the S-shaped sinoatrial node artery. AJR Am J Roentgenol. Jun 2008;190(6):1569–75. doi: 

  4. Radiopaedia [Internet]. Grand Rapids, MI: Advanced Radiology Services Foundation; c2022. Weerakkody Y, Feger J. Posterior left ventricular artery; s2021 Jan [cited 2022 Aug 14]. Available from: 

  • E-ISSN: 1947-6108
  • Published by Houston Methodist DeBakey Heart & Vascular Center
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