see also:

• thoracic outlet syndrome

• subclavian steal syndrome is an uncommon condition characterised reduced arterial supply to the opposite arm or carotids/vertebrals when the affected arm is exercised
• this occurs when the subclavian artery is impinged or occluded and supply to the arm is retrograde down the ipsilateral vertebral artery which “steals” it from the controlateral vertebral artery

• signs of arterial insufficiency of affected arm may be present
• BP lower in affected arm compared to contraleral arm
• may cause:
  • syncope
  • vertigo
  • other neurology

• cervical rib
• atherosclerosis
• Takayasu's arteritis