Normal coronary artery anatomy is characterised by two ostia centrally placed in the right and left sinus of Valsalva. The main left coronary artery (LCA) originates from the left ostium, branching into the left anterior descending artery and circumflex artery, which courses around the left atrioventricular groove; the right coronary artery (RCA) arises from the right ostium, providing an infundibular branch to the anterior side of the heart, and then courses backward in the atrioventricular groove. The three main coronary arteries branch superiorly to the atria and inferiorly to the ventricles; they end in broom-like arborisations, which penetrate the myocardium.¹ Because of ventricular contraction myocardial perfusion of the left ventricle occurs mainly in diastole, while the myocardium of the right ventricle is perfused during both heart cycles.^2–4

Clinical suspicion that a patient’s problems may be the result of coronary anomalies remains an important challenge in diagnosis, especially in children. Haemodynamically significant congenital anomalies of coronary arteries occur as isolated or primary forms and as secondary forms in association with congenital heart disease (CHD) (pulmonary atresia with intact interventricular septum or hypoplastic left heart syndrome with aortic atresia and severe mitral stenosis) (table 1). In this article only isolated/primary forms will be discussed.

INCIDENCE

Overall, anomalies of the coronary arteries are rather rare and the incidence of primary congenital coronary anomalies varies from 0.3% in a necropsy series reported by Alexander and Griffith to 1.6% of patients undergoing cardiac catheterisation in a series of more than 38 000 patients.⁵ Although these anomalies are rare, they may be seen with haemodynamic or myocardial perfusion abnormalities or high risk anatomy for accelerated atherosclerosis; they may result in symptoms varying from dyspnoea to sudden death. The milder forms escape detection both during life …