A 48-year-old patient with hyperlipidaemia and a long term history of stable angina pectoris was admitted to the emergency department with symptoms of acute chest pain and dyspnoea. Initial ECG showed sinus bradycardia with no signs of ischaemia and the patient was admitted for further tests. Cardiac catheterisation and a cardiac CT were performed which revealed a rare coronary anomaly.
Initially the calcium scoring showed no evidence of coronary calcifications, with a resulting Agatson score of 0.
CT angiography performed subsequently revealed a common origin of both right coronary artery (RCA) and left main trunk (LM), with both arising from the right sinus of Valsalva. There was an anomalous course of the LM to the left between the aorta and the pulmonary trunk (interarterial course). After the bifurcation of unusually long LM into its branches, the left anterior descending artery (LAD) and the circumflex artery (CX) were found in their correct anatomical locations, namely the anterior interventricular groove (LAD) and the left sulcus atrioventricularis (CX). The right coronary artery (RCA) showed a normal course and calliper, and represented the dominant artery (right coronary dominance). All the coronary arteries were free of any stenosis or other signs for coronary artery disease (CAD).
The incidence of coronary anatomy anomalies in general is reported to be about 1%, and the incidence of interarterial course of the left coronary artery is estimated at 1.3% of all coronary anomalies. [1,2]
The large group of coronary anomalies can be divided into anomalies of origin and distribution and are usually asymptomatic and not clinically significant . In symptomatic patients with coronary anomalies the most common symptom is angina pectoris, particularly in patients with an interarterial course.  For visualisation of the origin and course of the coronary arteries the method of choice is cardiac CT, because cardiac catheterisation has inherent limitations to accurately study coronary anomalies, because of its two dimensional display and the non-visualisation of adjacent vascular structures. 
In most of the cases the coronary arteries have a benign course, but there is also an interarterial or malignant course of coronary arteries which is a rare. It is however an important cause of myocardial infarction and sudden death, particularly in children and competitive athletes.  There are two variants of this anomaly, the malignant course of RCA or of LM. The benign anomalies of the course which are more common include: retroaortic course, prepulmonic course and a septal (subpulmonic) course. Risk factors for myocardial ischaemia in anomalous artery patients can be smoking, hypercholesterolemia, a past history of diabetes mellitus, dyslipidaemia, obesity, retrosternal chest pain, and a positive family history of premature coronary artery disease. 
Left coronary artery arising from the right sinus of Valsalva is a serious abnormality, and patients require treatment, which is usually surgical, but also dependent on several factors such as age, symptoms and signs of myocardial ischaemia.  The patients with benign courses of coronary arteries are at low risk and do not require surgery.
The patient in this case report was discharged from the hospital, but was scheduled for an elective cardiosurgical procedure.
Written informed patient consent for publication has been obtained.
 José María Pérez-Pomares, José Luis de la Pompa, Diego Franco, Deborah Henderson, Siew Yen Ho, Lucile Houyel, Robert G. Kelly, David Sedmera, Mary Sheppard, Silke Sperling, Gaetano Thiene, Maurice van den Hoff, Cristina Basso, Congenital coronary artery anomalies: a bridge from embryology to anatomy and pathophysiology—a position statement of the development, anatomy, and pathology ESC Working Group, Cardiovascular Research, Volume 109, Issue 2, 1 February 2016, Pages 204–216, (PMID: 26811390)
 Angelini P, Villason S, Chan AV. Coronary artery anomalies: a comprehensive approach. In: Angelini P, editor. Normal and Anomalous Coronary Arteries in Humans. Philadelphia: Lippincott Williams & Wilkins; 1999:42.
 Abdulshakour, Bothaina & Saeed, Muhammad & Mohiuddin, Taher. (2019). Anomalous coronary artery anatomy with a single coronary ostium arising from the right coronary: a case report and literature review. International Medical Case Reports Journal. Volume 12. 135-141. 10.2147/IMCRJ.S194029. (PMID: 31118833)
 Kacmaz F. Isiksalan Ozbulbul. N. Alyan O. Maden O. Demir A. D. Atak R. Senen K. Erbay A. R. Balbay Y. Olcer T. Ilkay E. 2008Imaging of coronary artery fistulas by multidetector computed tomography: is multidetector computed tomography sensitive? Clin Cardiol. 31, 1, (Jan. 2008), 41-47. (PMID: 18203118)
 Carrel T. Surgical treatment of anomalous aortic origin of coronary arteries: the reimplantation technique and its modifications. Operative Tech Thoracic Cardiovasc Surg. 2016 Autumn;21(3):178–201. (PMID: 30505744)