Anomalous origin of LMCA off RCA with malignant course

Case contributed by Craig Hacking


Severe AS for AVR. Coronary angio shows anomalous anatomy.

Patient Data

Age: 65 years
Gender: Male

Coronary arteries

Anomalous coronary anatomy is demonstrated, with both the right and left coronary arteries arising from a large common trunk of the right coronary cusp.

The right coronary artery is large, with minor proximal tortuosity prior to otherwise a normal course along the right AV groove. Moderately large posterolateral branch. Moderate PDA to the apex. Minor calcific plaque at the proximal RCA and proximal PDA. Minor non-calcified plaque at the distal RCA prior to its bifurcation. None of these is stenotic (>50%)

The left coronary artery does not have an acute angle take off but has an acute angle turn soon after its origin, where it takes an anomalous course between the pulmonary outflow tract and aortic root. After giving rise to some septal branches, it courses posterior to the anterior interventricular groove, gives off a moderate size branch that courses along the interventricular groove LAD before bifurcating an anterior branch that gives rise to 2 large diagonal branches, and a posterior branch that becomes the circumflex after giving off another large diagonal branch. The circumflex after giving off the OM1 becomes very small.

Non-stenosing (<50%) mixed plaque at the distal LCA prior to its terminal bifurcation. Non-calcific nonstenosing plaque at the proximal circumflex. Minor calcific plaque at the circumflex just prior to OM1.

Tiny arterial branch arises from the left cusp with a short course between the left atrial appendage and right pulmonary outflow tract.


Heavy calcification of the aortic valve, possibly bicuspid. The LV wall appears thickened.

Other findings



Anomalous coronary anatomy with a right coronary cusp common trunk origin of the RCA and LCA, with LCA having a malignant inter-arterial course between the pulmonary outflow tract and aortic root.

Case Discussion

The malignant inter-arterial course of the anomalous LMCA off RCA is a known cause of sudden cardiac death.

Treatment involves surgical reimplantation of the coronary artery.

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