Four-Dimensional Magnetic Resonance Flow Analysis Clarifies Paradoxical Symptoms in a Patient With Aortic Bypass and Retrograde Flow Mimicking Subclavian Steal

Abstract

We present the case of a 39-year-old physically active male amateur hockey player with a history of preductal coarctation of the aorta repaired at the age of 10 years with an ascending-to-descending aortic conduit. He presented with neurological symptoms, which were present at rest but paradoxically resolved with physical exertion, including left upper extremity weakness, dizziness, visual changes, and facial tingling. A 2008 echocardiogram demonstrated a bicuspid aortic valve with moderate regurgitation and a mildly to moderately dilated and hypertrophied left ventricle with ejection fraction of 50%. A 2009 carotid Doppler ultrasound examination demonstrated high-velocity retrograde flow in the left vertebral artery, which reduced on exertion. Stenosis of the subclavian artery, and thus subclavian steal, which has been shown to cause neurological symptoms, was ruled out by a 2010 arteriogram.1 A recent magnetic resonance imaging (MRI) evaluation (in 2011) demonstrated worsening (moderate to severe) aortic insufficiency with a clearly visible asymmetrical diastolic flow jet (Figure 1, white arrows), mild decrease of left ventricular ejection fraction, and a patent aortic bypass conduit. Figure 1. Cardiac magnetic resonance angiography demonstrating aortic valve insufficiency and a clearly visible asymmetrical flow jet (white arrows, regions with signal void in the left ventricle). The individual images represent …