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

We present the case of a 39-year-old physically active maleamateur hockey player with a history of preductal coarc-tation of the aorta repaired at the age of 10 years with an ascending-to-descending aortic conduit. He presented with neuro-logical 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) dem