In a patient with subclavian steel syndrome true is

(B) The BP is decreased on the ipsilateral side # Subclavian steal syndrome. If the first part at the subclavian artery is obstructed, the vertebral artery may provide a collateral circulation into the arm by reversing its direction of flow.> This may cause periods of cerebral ischaemia.> The classic syndrome of syncopal attack and visual disturbance associated with arm exercise and a diminished blood pressure in the affected limb is rather rare.> Asymptomatic reversal of flow in the vertebral artery, recognized either by duplex scanning or angiography, is much commoner.> In symptomatic patients, percutaneous transluminal angioplasty may relieve the problem, or the situation may be corrected by endarterectomy or a bypass from the ipsilateral common carotid artery to the third part of the subclavian artery.