SHM Converge Scientific Abstract ePoster Gallery-A Case of Coronary Subclavian Steal Syndrome

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Coronary subclavian steal syndrome (CSSS) is an important cause of chest pain in patients with prior CABG using a left internal mammary artery (LIMA) to LAD graft. It occurs when hemodynamically significant proximal left subclavian artery stenosis reduces blood flow into the LIMA graft, and blood may flow retrograde to supply the arm, “stealing” blood from the coronary circulation.<br /><br />This case describes a 75-year-old man with coronary artery disease and remote CABG (LIMA-LAD, SVG-OM, SVG-RCA) who presented with positional and exertional chest pain plus dizziness. Evaluation showed a marked blood pressure difference of about 40 mmHg between the right and left arms. CT angiography demonstrated severe stenosis at the ostium of the left subclavian artery, proximal to the LIMA origin. Catheterization confirmed a 40 mmHg pressure gradient between the left subclavian artery and the aorta.<br /><br />Because the lesion was not suitable for percutaneous stenting, vascular surgery performed a carotid-subclavian bypass. After surgery, the inter-arm blood pressure difference fell to less than 5 mmHg, and the patient’s anginal and dizziness symptoms resolved.<br /><br />The report emphasizes that subclavian artery stenosis can compromise coronary blood flow and may lead to ischemia, myocardial infarction, or sudden cardiac death. CSSS affects an estimated 0.2%–6.8% of patients with LIMA-LAD grafts. A systolic blood pressure difference of 20 mmHg or more between arms may be the first clue, supporting routine bilateral brachial blood pressure checks after CABG. ESC guidelines recommend endovascular treatment first for symptomatic CSSS when feasible.<br /><br />Key learning points: maintain a high index of suspicion for noncoronary causes of post-CABG chest pain, screen with bilateral arm blood pressures, and recognize that blood pressure should be measured on the side distal to stenosis because it may read lowest there.

Asset Subtitle

Prasanti A. Kotta

Meta Tag

Author List Ali E Denktas, Joshua R Hirsch, Maria Lee, Mirza U Khalid, Patrick T Lynch, Prasanti A. Kotta, Priscilla Liem

Category Clinical Vignettes

Concept Coronary Subclavian Steal Syndrome

Concept Left Internal Mammary Artery Graft

Concept Proximal Subclavian Artery Stenosis

Concept Inter-Arm Blood Pressure Difference

Concept Myocardial Ischemia

Distinguished Non-Finalist

Presenter Organization Baylor College of Medicine

Presenting Author Prasanti A. Kotta

Track Adult

Keywords

coronary subclavian steal syndrome

LIMA-LAD graft

subclavian artery stenosis

CABG

chest pain

inter-arm blood pressure difference

carotid-subclavian bypass

myocardial ischemia

CT angiography

retrograde blood flow

Coronary Subclavian Steal Syndrome

Left Internal Mammary Artery Graft

Proximal Subclavian Artery Stenosis

Inter-Arm Blood Pressure Difference

Myocardial Ischemia