Dizziness due to Subclavian Steal

Timothy C. Hain, MD . Page last modified: February 8, 2011

In the subclavian steal syndrome, due to stenosis of the subclavian artery, blood may be supplied to the arm via retrograde flow in the vertebral artery. This causes brainstem symptoms due to low blood flow in the vertebral. Symptoms may be provoked by arm exercise.

In A is a normal patient ultrasound (subclavian and Right vertebral artery) in B: sublavian stenosis patient (high velocity: 252 cm/sec) and the right vertebral artery with flow reversal.


Patient B: had bilateral fluctuating hearing loss, recurrent vertigo, and asymmetry in the radial pulse and blood pressure between both sides.

Higher resolution tif image is here -subclavian steal (robo subclavio)
(images are courtesy of Dr. Dario Yacovino)