A Rare Case of Exertional Angina in an Adult Due to Anomalous Origin of the Circumflex Artery from the Right Main Pulmonary Arte

Anomalous coronary arteries occur in less than 2% of the general population.¹ Anomalous origin of the left circumflex artery (LCx) from the right coronary artery or the right sinus of valsalva is the most common coronary anomaly reported in angiographic series and necropsy studies.² The LCx origin from the pulmonary artery is a very rare anomaly. As an isolated lesion, anomalous origin of the LCx from the pulmonary artery as a cause of classic angina in adults is extremely uncommon. Case Report. A 51-year-old patient was referred to our clinic for evaluation of chest pain and an abnormal stress test. She was experiencing frequent exertion-related episodes of chest pain described as pressure or fullness in the left chest without associated symptoms. The symptoms were considered classic for new-onset angina. The patient had no significant personal or family history. Her pulse and blood pressure were normal. There was no evidence of any hyperdynamic circulation. A localized pansystolic murmur was heard at the base of the heart. The resting electrocardiogram (ECG) was normal. The patient underwent stress Cardiolite testing which revealed a moderate-sized area of ischemia in the lateral and posterolateral wall with no evidence of previous myocardial infarction. She subsequently underwent diagnostic left heart catheterization. The left coronary injection filled the left anterior descending (LAD) artery and showed early filling of a tortuous and dilated vessel in the atrioventricular groove. Subsequent larger-volume injections filled up the LCx, which on fluoroscopy drained behind the aorta into the right pulmonary artery (RPA). The right caudal and left lateral views exhibited large tortuous obtuse marginal filling up from the LAD collaterals to the LCx and draining into the RPA. The anatomy presented a true arteriovenous fistula with coronary steal from the LAD, with an aberrant LCx acting as a conduit to the pulmonary artery. There were no other lesions in the LAD or LCx. Right-sided hemodynamics showed normal pressures and cardiac output. Selective sampling of oximetry from the RPA did not exhibit any step-up in oxygen saturations (Figures 1–3). Discussion Anomalous left circumflex coronary origin from the pulmonary artery is a rare finding. It is usually noted incidentally on angiography in patients being evaluated for ischemic heart disease.³ The majority of the patients with this anomaly develop congestive heart failure or die within two years of the onset of ischemic symptoms.⁴ Survival is usually dependent upon the development of collateral vessels. The presentation in adults may be in the form of new-onset angina, shortness of breath, abnormal ischemic changes on ECG, abnormal stress electrocardiography, a continuous murmur or sudden cardiac death.^4,5 The mainstay of treatment is surgical legation of the LCX at the origin alone, ligation with aorta-coronary bypass or reimplantation of the LCx to the aorta. The various surgical options are equally effective in younger patients, however, data are limited for adults. Only one reported case of LCx ligation with a saphenous vein graft to the obtuse marginal branch has been reported in an adult.⁶ Our recommendation for the patient described here included surgical ligation of the LCx with vein grafting to the obtuse marginal artery.

1. Baltaxe HA, Wixson D. The incidence of congenital anomalies of the coronary arteries in adult population. Radiology 1977;122:47–52. 2. Page HL, Engel HJ, Cambell WB, Thomas CS Jr. Anomalous origin of the left circumflex coronary artery: Recognition, angiographic demonstration and clinical significance. Circulation 1974;50:768–773. 3. Roberts WC. Major anomalies of coronary artery origin seen in adulthood. Am Heart J 1986;111:941–963. 4. Levin DC, Fellows KE, Abrams HL. Hemodynamically significant primary anomalies of the coronary arteries: Angiographic aspects. Circulation 1978;58:25–34. 5. Vesturland T, Thomsen PEB, Hensen OK. Anomalous origin of the left coronary artery from the pulmonary artery in an adult. Br Heart J 1985;54:110–112. 6. Mirkhani SH, Delavarkhan M, Bayat H, Sanatkar M. Anomalous connection of left circumflex artery to pulmonary artery. Asian Cardiovasc Thorac Ann 2002;10:334–335.