A 65-year-old previously asymptomatic woman with a history of tobacco use presented after experiencing an hour of chest pain and syncope. A 12-lead electrocardiogram revealed an inferior ST-elevation myocardial infarction. Coronary angiography revealed an acute thrombotic occlusion of the right coronary artery (Fig. 1); however, there was difficulty in maneuvering diagnostic catheters to the coronary ostia. Subsequent aortography revealed a double aortic arch (Fig. 2). After revascularization, 64-slice computed tomography (CT) of the aorta (Fig. 3) showed a dominant right aortic arch (Fig. 4A) to the right of the trachea, with separate ostia of the right subclavian and common carotid arteries. A more inferiorly located left aortic arch (Fig. 4B) connected the ascending and descending aorta at the left of the trachea, with separate ostia of the left subclavian and common carotid arteries. No vascular ring was seen. The aorta was also right sided (Fig. 4C).
A double aortic arch is a variant of vascular ring, occurring in 0.05% to 0.3% of the general population.1 It can encircle the trachea and esophagus via connected segments of aortic arch, causing symptoms of dyspnea, stridor, or dysphagia in infancy or early childhood2,3 ; rarely, these symptoms develop in adulthood.4–,6 Double aortic arch is the result of persistence of both the left and right embryonic 4th arches and dorsal aortas.7 Aortic arch “sidedness” is the side of the trachea that the arch passes as it crosses a mainstem bronchus.8 Cardiovascular CT can provide definitive evaluation of the course and orientation of these aortic arch variants and of associated cardiac anomalies. This case illustrates the supplementary role of CT with invasive aortography in diagnosing a rare aortic anatomic variant.
Section Editor: Raymond F. Stainback, MD, Department of Adult Cardiology, Texas Heart Institute, 6624 Fannin St., Suite 2480, Houston, TX 77030
From: Division of Cardiology, Department of Medicine (Drs. Akhondi, Tabibiazar, and Yang) and Cardiovascular Imaging Section, Department of Radiology (Dr. Ruehm), University of California at Los Angeles, Los Angeles, California 90095