Reversed flow in internal mammary artery conduit and vertebral artery with left subclavian artery occlusion causing angina and vertigo: The coronary–subclavian steal syndrome

Abstract

Coronary subclavian steal syndrome (CSS) is the phenomenon of retrograde flow (steal) through the left internal mammary artery (LIMA) after coronary bypass grafting with concurrent proximal stenosis or occlusion of the ipsilateral subclavian artery. The pathophysiology parallels that of a classical subclavian steal (SS) phenomenon. In the presence of a severe subclavian artery stenosis, steal phenomenon from the LIMA to the left subclavian artery may cause ischaemia in the grafted arterial bed (LAD), especially during physical activity related to the left upper extremity. In addition classical subclavian steal with retrograde filling of the left vertebral artery may be seen. Symptomatic CSS is a recognised but uncommon cause of residual angina.