Inter-arterial course of the right coronary artery

Dr Craig Hacking et al.

Inter-arterial course of the right coronary artery (RCA), also known as a malignant variant, may occur if the right coronary artery has an aberrant origin from the the left coronary sinus. It is an uncommon anomaly with potential risk of cardiac ischaemia.

When the right coronary artery arises aberrantly in this manner, there are three possible courses it may take:

  • inter-arterial with intramural segments: highest risk
  • inter-arterial and extramural
  • inter-atrial

An inter-arterial course occurs when the artery passes between the ascending aorta and the pulmonary trunk.

Treatment and prognosis

Some consider this anomaly malignant, indicating that it has an increased risk of cardiac ischaemia, myocardial infarction, and possibly sudden death. Others consider the aberrant course of the right coronary artery to be less concerning than an aberrant course of the left coronary artery. Repair strategies vary depending on the institution's level of concern.

The cause of ischaemia from this the anomaly is not completely understood. Classically, extrinsic compression of the coronary artery between the aortic root and the right ventricular outflow tract was considered to be the primary problem, but there is increasing evidence that risk may be mostly due to the anomalous coronary's flow-limiting 'slit'-like orifice.

The highest risk situation is considered to be the inter-arterial course with segments that course through the wall of the aorta.

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Article Information

rID: 36573
Systems: Cardiac, Vascular
Section: Anatomy
Tags: variants, rca, ctca
Synonyms or Alternate Spellings:
  • Inter-arterial course of the RCA
  • Inter-arterial course of right coronary artery
  • Malignant variant inter-arterial course of right coronary artery

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Cases and Figures

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    Case 1: malignant inter-arterial course of RCA
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    Case 2: inter-arterial course of RCA
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    Case 3
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