Retrograde vertebral artery flow on duplex ultrasound

The duplex ultrasound is from a 68-year-old female, who is an active smoker and who has a history of peripheral artery disease and coronary heart disease. She was known to have asymptomatic moderate bilateral carotid artery stenosis and on examination had differential bilateral arm pressures (50 mmHg gradient) but had no symptoms suggestive of subclavian steal or other symptoms of upper extremity ischemia.