A 58 year old woman with hypertension, hypercholesterolaemia, and family history of coronary heart disease presented with a five year history of exertional chest discomfort, relieved by rest and nitrate administration.
Coronary angiography demonstrated a single left coronary ostium (aortography confirmed absence of right coronary artery), left circumflex artery was dominant, and the right coronary artery arose from an unusual location, just after the first septal branch of the left anterior descending artery (LAD), passing anteriorly to the pulmonary trunk and crossing to the right side of the heart. According to the Lipton classification, this anomaly could be classified as LII-A (panels A and B).
Interestingly, although the coronary tree was generally free of atheroma, a significant stenosis was demonstrated within the abnormal artery (panels A and B, arrowheads). This was wired and stented directly with a 2.75 × 8 mm stent, but resulted in some impingement in the main LAD, perhaps due to “snow-plough” (panel C, arrowhead). After preinflation of both branches, a “kissing balloon” inflation was performed in the LAD and in the aberrant vessel, with good angiographic final appearance (panel D).
Coronary artery anomalies occurs in 0.64–5.6% of patients undergoing coronary angiography. They have been associated with increased risk of sudden death, mainly when an aberrant branch is compressed between the great vessels. In our case the unusual anatomy may have played a role in determining the location of this single lesion, as an almost right angle takeoff is associated with decreased mechanical shear stress, and could predispose to atheroma formation.