Malignant right coronary artery. Image findings in 64-slices CT coronary angiography

Clinical History

The authors present a case of an aberrant right coronary artery (RCA) (interarterial or malignant type) at a 64-years-old patient, presented with symptoms of unstable angina. Image findings at 64-multidetector CT coronary angiography are described.

Imaging Findings

A 64-year-old male patient was presented to our department for a 64-slices CT coronary angiography examination due to unstable angina. The patient was thoroughly informed about the examination technique and gave oral consent. A 64-multislice CT scanner (Aquilion, Toshiba Co) and a Vitrea 2 version 3.9 workstation (Toshiba Co) were used for the examination and image post-processing respectively. Right coronary artery originated from the left aortic sinus, from separate ostium from the left coronary artery (image 1), showing a course between the aorta and pulmonary artery (interarterial type or malignant RCA) (image 2). No decrease of the vessel lumen was demonstrated (image 1).

Discussion

Coronary anomalies are identified incidentally and constitute 1-3% of all congenital malformations of the heart. (1) The majority of these lesions are of benign course. However, a study in 33.735 young athletes showed that 12% of sudden deaths in this group were the result of a congenital coronary anomaly. (2) Therefore, is mandatory to exclude such an anomaly in a young patient when he presents with a history of exertional syncope or chest pain. The etiology of coronary anomalies is still unidentified. Maternal transmission, familiar predispositions, Klinefelter’s or trisomy 18 syndromes and other causes have been proposed. However, most of the patients with coronary anomalies do not present any of the above predisposing factors. (1 book) Malignant RCA or interarterial type of RCA is the anomaly where the RCA originates from the left aortic sinus with a course between the aorta and the pulmonary artery. This type of aberrant origin of the RCA can also take two more different anomalous courses: ventral to the pulmonary artery and dorsal to the aorta. (3) This type of coronary anomaly is responsible for myocardial ischemia and sudden death and this is the reason why it is called “malignant”. Various mechanisms have been proposed for the decreased blood flow in the RCA, such as: (α) compression of the RCA between aorta and pulmonary artery, especially during exercise, where blood pressure and volume increase and cause pulmonary outflow tract and aortic root dilatation, as well as increased coronary blood flow, (β) a sharp kink of the vessel lumen at its origin or a true stenosis of the vessel ostium, (ψ) a spasm at the proximal segment of the aberrant RCA due to decreased blood flow at the coronary arteries (3,4,5) Therapeutically, surgical treatment is nowadays amenable and therefore early recognition of this possible fatal anomaly is crucial. 64-multidetector coronary angiography is easy, fast, and non invasive examination, and plays an important role in the diagnosis and treatment of coronary congenital anomalies, especially in symptomatic children and young adults.

Differential Diagnosis List

Final Diagnosis

Malignant or interarterial right coronary artery

URL:	https://eurorad.org/case/5946
DOI:	10.1594/EURORAD/CASE.5946
ISSN:	1563-4086