Subclavian Steal Syndrome
A 90-year-old woman who underwent coronary artery bypass graft surgery 15 years ago was brought to the Emergency Department from her assisted living facility after developing chest pain, dyspnea, and diaphoresis. On arrival, she continued to have chest pain and exhibited signs of congestive heart failure. Her ECG revealed 2-mm ST-segment depressions across the precordium associated with 2-mm ST-elevations in aVR (Figure 1). Given this clinical picture, she was urgently brought to the cardiac catheterization laboratory, where angiography revealed totally occluded native coronaries and an occluded saphenous vein graft to an obtuse marginal artery. The saphenous vein graft to the right coronary circulation was patent as was the left internal mammary artery (IMA) bypass to the left anterior descending artery. However, there was a severe (99%) left subclavian artery stenosis (Movie I in the online-only Data Supplement). Stenting of the left subclavian artery resulted in the resolution of the patient’s chest pain and electrocardiographic abnormalities. She was discharged to home 9 days later.
“Subclavian steal” refers to a phenomenon of flow reversal in a branch of the subclavian artery that is the result of an ipsilateral hemodynamically significant lesion of the proximal subclavian artery.1,2 Subclavian stenoses, however, are most often asymptomatic and therefore do not require specific therapy other than that directed at the underlying etiology. “Subclavian steal syndrome” can become manifest in some patients with symptoms of arterial insufficiency afflicting the brain,1–3 the upper extremity,2 or even the heart if part of the coronary circulation is supplied via an IMA graft,4 as was the case in this patient.
Pathophysiology of Subclavian Steal
A subclavian steal syndrome may occur when a significant stenosis in the subclavian artery compromises …