Variant of subclavian steal syndrome: unusual anatomical relationship between left subclavian artery and left vertebral artery.

A woman in her 70s presented to her general practitioner (GP) with a 3-month history of left upper arm pain and weakness. A significant difference in bilateral blood pressures was noted and a further history elicited coolness in her left arm without functional compromise. A CT angiography revealed variant subclavian steal syndrome with a subclavian arterial stenosis, which was proximal to both the internal mammary and thyrocervical trunk and her left vertebral artery originating from the aortic arch.