circumflex artery (Cx) near the origin

For the treatment of stenosis near the origin of either the left anterior descending artery or the left circumflex artery, one autoperfusion catheter was used to dilate the lesion while another was used to maintain perfusion of the nonstenosed vessel, which would normally suffer from a decrease in blood flow.
http://www3.interscience.wiley.com/journal/112136475/abstrac...



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Note added at 1 hr (2010-03-11 09:39:31 GMT)
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It occurs at specific “vulnerable sites”: (1) in the proximal portion of the left anterior descending coronary artery, (2) in the right coronary artery near the origin of its marginal branch, & (3) in the left circumflex at the origin of its first obtuse marginal branch1.
http://wichita.kumc.edu/hastings/dyslipidemias.pdf

Also possible:
close to the origin
e.g.:
14 years after a mitral valve replacement procedure, Mulpur and colleagues5 documented by coronary angiography a lesion that was similar to hemangioma, close to the origin of the Cx
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2435437/

In 30 patients the first marginal arose so close to the origin of the proximal circumflex and LAD that the conventional and axial views could not determine its true origin.
http://radiology.rsna.org/content/139/1/39.full.pdf