Subclavian artery steals blood from the vertebral artery causing posterior circulation syndromes
- Compromises vertebral arterial blood supply
- The subclavian vein is a continuation of the axillary vein, beginning at the lateral border of the first rib. It passes anterior to scalenus anterior.
- The subclavian and internal jugular vein unite to form the brachiocephalic vein, subsequently, the left and right brachiocephalic veins unite to form the superior vena cava.
- Obstruction usually atheromatous of the subclavian artery proximal to the origin of the vertebral
- Ischaemia when there is ipsilateral upper limb exercise as there is then reverse flow down the vertebral.
- Dizziness, ataxia, loss of consciousness, visual loss
- Angina with left arm exercise when there is a LIMA graft (CABG)
- Doppler shows reverse vertebral blood flow
- Aortic Angiography will show a stenotic lesion
- Antiplatelets, statins, smoking cessation, manage vascular risks
- Consider surgery or angioplasty or vascular bypass