Total Left Subclavian Artery Occlusion Causing Coronary Subclavian Steal Syndrome and Reversible Left Ventricular...

Coronary subclavian steal syndrome (CSSS) is a rare phenomenon that occurs due to severe stenosis of the subclavian artery, resulting in retrograde vertebral and left internal mammary artery (LIMA) flow. We present a 60-year-old man with severe peripheral artery disease (PAD) and coronary artery bypass graft (CABG) involving the LIMA-left anterior descending artery (LAD) who presented with left arm claudication, vertigo, angina, and heart failure. This case highlights a patient with a complex set of symptoms across multiple organs with one unifying culprit in the left subclavian artery. Prompt identification and treatment of a total subclavian occlusion resulted in restoration of vertebral and LIMA-LAD flow with resolution of angina, vertigo, and left ventricular systolic dysfunction. Coronary subclavian steal syndrome is an underrecognized diagnosis that should be on the differential for patients with inter-arm pressure differences and a history of CABG involving the LIMA-LAD. Routine surveillance should be pursued in high-risk patients. Early detection and treatment may improve symptoms and potentially contribute to recovery of left ventricular systolic dysfunction in select patients.