Ectopic Origin of Right Coronary Artery

Axial CT image shows an ectopic origin of the right coronary artery (arrow) arising from the left cusp and passes between the ascending aorta and the right ventricular outflow tract in the "intraseptal" course.

Coronary Artery Anomalies

• 1% of all patients undergoing cardiac catheterization
• Three types: ectopic origin from a coronary cusp (like our case), absent coronary artery, ectopic origin from a main pulmonary artery
• 20% causes life threatening symptoms such as arrhythmias, syncope, myocardial infarction or sudden death
• MDCT can clearly show the origin and course of several forms of anomalous coronary artery.

Anomalous Coronary Crossing Between Aorta and Main Pulmonary Artery/RV Outflow

• Either left coronary originating from the right cusp (sinus) or right coronary arising from the left cusp (sinus), if it courses between the aorta and MPA -- it is called "intervascular course" and is associated with poor outcome.
• If it courses between the aorta and RV outflow tract inferior to the plane of the pulmonic valve, it is "intraseptal course" and considered "comparatively benign"

Reference:

Datta J, White CS, Gilkeson RC, et al. Anomalous coronary arteries in adults: depiction at multi-detector row CT angiography. Radiology 2005;235:812-818.

Follow RiTradiology on Facebook, Twitter or Google Friend Connect