Summary: A 31-year-old female presents to the emergency department with chest pain.
Malignant variant of anomalous RCA
Axial maximum-intensity projection (MIP) and parasagittal images from a computed
tomography angiography (CTA) examination are provided. The axial MIP image
demonstrates the right coronary artery (RCA) arising from the left coronary cusp
just anterior to the origin of the left coronary artery (LCA). The parasagittal
image demonstrates the RCA passing between the ascending aorta and the right
ventricular outflow tract.
Congenital anomalies of the coronary arteries are rare,
occurring in approximately 1% of patients. Approximately 90% of these anomalies
involve the origins of the coronary arteries with the remaining 10%
representing coronary artery fistulas. The aortic valve normally has 3 cusps,
including the left coronary cusp, which gives rise to the left main coronary
artery, the right coronary cusp, which gives rise to the RCA, and the
non-coronary cusp, which does not have an associated coronary artery. The LCA usually
divides proximally into the left anterior descending coronary artery and the
circumflex coronary artery. The origins of the coronary arteries should be
perpendicular to the lumen of the aorta.
Many anomalies of the coronary arteries are incidental and
of no clinical significance, but some may be symptomatic and can result in
sudden cardiac death. There are 2 variants of an anomalous origin of the RCA,
benign and malignant. The malignant variant is much more common with the RCA
typically arising from the anterior aspect of the left coronary cusp between
the origin of the LCA and the anterior commissure. The RCA then courses between
the aorta and the pulmonary artery. The malignant nature of this variant is due
to the fact that the artery travels between 2 high-pressure systems, which may
compress the coronary artery, as well as the abnormal slit-like ostium of the
RCA as it arises from the aorta at an abnormal angle. It is postulated that
dilation of the aorta with exercise may result in further narrowing of the
ostium. The benign course of the RCA travels posterior and inferior to the
Patients with the malignant variant of anomalous RCA may be asymptomatic or present with angina,
myocardial infarction, or sudden death. Treatment consists of reimplantation of
the anomalous vessel to the right coronary cusp in young patients. Older
patients who have been asymptomatic may not need surgical treatment as the risk
of sudden cardiac death appears to decrease with age.
- Dodd JD, Ferencik M, Liberthson RR, et al. Congenital
anomalies of coronary artery origin in adults: 64-MDCT appearance. AJR Am J Roentgenol. 2007;188:W138-146.
- Datta J, White CS, Gilkenson RC, et al. Anomalous coronary
arteries in adults: Depiction at multi-detector row CT angiography. Radiology. 2005;235:812-818.