I would like to share this interesting case from couple of days ago.
A 63-year-old African American lady with acute coronary syndrome. During her catheterization, when injecting the left main coronary artery, the catheter slid and jumped into another vessel. That turned out to be the RCA originating just very close to the left main. A repeat cranial view, (angiogram 2.) Clarifies the relationship between to the separate ostia in the left coronary cusp.
CX was occluded and RCA has two proximal tandem lesions.
We elected to perform intervention on both vessels. Finding a guide catheter for the apparent RCA was a bit challenging, however we used a JR4 guide catheter but needed to engage the ostium with an interventional wire of the cusp and then advanced the JR4 guide catheter to the ostium of the aberrant RCA. The rest was straight forward.
I wonder, if we did not luckily jump in to the RCA from the left coronary cusp injection, we could have wasted long time trying to search for the RCA on the right coronary cusp. Rare anomaly, but keep it in mind!