Determining functional significance of subclavian artery stenosis using exercise thallium-201 stress imaging

Subclavian artery stenosis (SAS) is a rare lesion accounting for nearly 2.5% of all extracranial arterial occlusions. Symptoms from SAS usually relate to subclavian steal, and include syncope, vertigo, ataxia, and, rarely, upper limb paralysis or hemipareses. Upper extremity ischemia may result in intermittent or constant arm pain. The majority of patients with SAS are asymptomatic. Upper extremity ischemia is particularly unusual. More commonly, patients with significant SAS have symptoms of cerebral ischemia, which are usually triggered by vigorous motion of the arm on the side of the severe proximal subclavian obstruction. Stress exercise radionuclide imaging appears to be a valuable modality in determining the functional significance of SAS. We describe a case in which radionuclide imaging with thallium-201 after stress of the upper extremities was used for risk stratification of subclavian stenosis, and to help decide treatment options.