Navigating the Unexpected: Right Aortic Arch Unveiled During Left Heart Catheterization.

A right aortic arch (RAA) is an extremely rare congenital anomaly with seven identified variants. While most variants are asymptomatic, those with a vascular ring can be associated with severe symptoms. We present an incidental RAA finding during left heart catheterization (LHC) in a 68-year-old female with multiple morbidities presented with worsening angina. Her echocardiogram was significant for inferolateral wall akinesia, prompting LHC. The procedure was challenging with an unexpected course of the guide wire distally behind the cardiac shadow. Pressure tracing confirmed arterial access and contrast injection revealed RAA. A subsequent aortic computed tomography angiography (CTA) confirmed RAA with mirror-image branching. Abnormal origin and angle of aortic arch branches pose challenges in choosing the proper access. We used the right radial artery approach, but the left radial approach may be superior in providing a more proximal access and avoiding the abnormal origin of the right subclavian artery (RSA). Choosing the appropriate angiographic view is also of utmost importance, and the right anterior oblique view provided better visualization in our case. Aortic arch anomalies are confirmed by a CTA or magnetic resonance angiography (MRA) of the aorta. This case underscores the importance of identifying the aortic arch anomalies and the imposed challenges during the LHC.