The obtuse marginal branch is a branch of which coronary artery?

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Last updated: May 7, 2026 • View editorial policy

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Obtuse Marginal Branch Origin

The obtuse marginal (OM) branch is a branch of the left circumflex coronary artery (LCX). 1

Anatomical Context

The left circumflex artery arises from the left main coronary artery and courses along the left atrioventricular groove. As documented in the 2022 CAD-RADS guidelines, standardized coronary CTA reporting explicitly describes that "the left circumflex artery has no evidence of plaque or stenosis. It gives off patent obtuse marginal branches." 1

Key Anatomical Points:

  • Parent vessel: Left circumflex coronary artery (LCX)
  • Territory supplied: Lateral wall of the left ventricle 2
  • Clinical significance: The obtuse marginal artery is a key branch supplying the lateral left ventricular wall, and its occlusion can result in myocardial ischemia and serious cardiac events 2

Clinical Relevance

The obtuse marginal branches are consistently referenced in contemporary cardiovascular imaging guidelines as standard branches of the LCX system. Multiple case reports confirm this anatomy, describing pathology involving "the first obtuse marginal branch of the left circumflex artery" in various clinical scenarios including coronary dissection 3, fistulae 4, and acute occlusions 2.

In rare anatomical variants, an obtuse marginal branch may be unusually large and supply atypical territories (such as the left ventricular apex), but it remains a branch of the left circumflex artery regardless of its distribution pattern 5.

References

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.