subclavian steal syndrome
Pronunciation: sub-KLAY-vee-an steal SIN-drome
Vascular condition where proximal subclavian artery stenosis causes retrograde flow in the ipsilateral vertebral artery, 'stealing' blood from the posterior cerebral circulation.
Full Definition
Subclavian steal syndrome occurs when significant stenosis or occlusion of the proximal subclavian artery, typically proximal to the vertebral artery origin, creates a pressure differential that results in retrograde flow through the ipsilateral vertebral artery. This reversal of flow direction effectively 'steals' blood from the posterior cerebral circulation to supply the affected upper extremity, particularly during exercise. The syndrome can manifest as vertebrobasilar insufficiency symptoms including dizziness, ataxia, or visual disturbances, often precipitated by upper extremity exertion. Imaging evaluation includes duplex ultrasound to demonstrate flow reversal, and cross-sectional angiography to assess the degree of subclavian stenosis.
Usage
Usage note: Syndrome vs. phenomenon: use 'syndrome' when referring to the clinical condition, 'phenomenon' for the hemodynamic observation.
In Context
- "Duplex ultrasound confirmed subclavian steal syndrome with complete flow reversal in the left vertebral artery." — Vascular ultrasound report