Ramus intermedius artery
Citation, DOI and article data
The ramus intermedius is a variant coronary artery resulting from trifurcation of the left main coronary artery 1. It is present in ~20% (range 15-30%) 2-3 of the population.
It can have a course similar to the obtuse marginal branches of the left circumflex artery or the diagonal branches of the left anterior descending artery and thus can supply either the anterior or medial aspect of the heart 1.
The peculiarity of this vessel is it does not run along an anatomical groove and imply slides over the free surface of left ventricle instead.
In practice, even if there is not a true trifurcation, some cardiologists may term a prominent early branching (high origin) obtuse marginal artery a ramus branch if it supplies the territory of small diagonal branches since there is an inverse relationship between the size of the ramus intermedius and the size and distribution of the diagonal branches.
- 1. Kini S, Bis KG, Weaver L. Normal and variant coronary arterial and venous anatomy on high-resolution CT angiography. AJR Am J Roentgenol. 2007;188 (6): 1665-74. doi:10.2214/AJR.06.1295 - Pubmed citation
- 2. Koşar P, Ergun E, Oztürk C et-al. Anatomic variations and anomalies of the coronary arteries: 64-slice CT angiographic appearance. Diagn Interv Radiol. 2009;15 (4): 275-83. doi:10.4261/1305-3825.DIR.2550-09.1 - Pubmed citation
- 3. O'Brien JP, Srichai MB, Hecht EM et-al. Anatomy of the heart at multidetector CT: what the radiologist needs to know. Radiographics. 2007;27 (6): 1569-82. Radiographics (full text) - doi:10.1148/rg.276065747 - Pubmed citation
- 4. Paolillo V, Gastaldo D, Vaudano G. An unusual course of the ramus intermedius: shown by multislice computed tomographic coronary angiography. (2006) Texas Heart Institute journal. 33 (3): 406-7. Pubmed
- 5. Paolillo V, Gastaldo D, Vaudano G. An unusual course of the ramus intermedius: shown by multislice computed tomographic coronary angiography. (2006) Texas Heart Institute journal. 33 (3): 406-7. Pubmed