Coronary subclavian steal syndrome in the emergency department - A case report

Coronary Subclavian Steal Syndrome (CSSS) is a rare condition of blood flow reversal, in patients who have undergone Coronary Arterial Bypass Graft (CABG) with a Left Internal Mammary Artery (LIMA) to Left anterior descending (LAD) graft, who have concomitant left subclavian artery stenosis. The left subclavian artery stenosis results in retrograde blood flow from the coronary circulation through the LIMA- LAD graft to the left subclavian artery, causing cardiac ischemia.

We report a case of a 77-year-old Female with previous CABG (LIMA to LAD graft) who presented to the Emergency department (ED) with chest pain. Her Electrocardiogram (ECG) showed ST elevations in aVR and widespread ST depressions in the anterior, lateral and inferior leads with a raised high sensitivity Troponin. A diagnosis of Non-ST Elevation Myocardial Infarction (NSTEMI) was made, and she underwent Coronary Angiogram which revealed relatively patent grafts that could not explain her presentation. She was found to have left subclavian artery stenosis and subclavian artery angioplasty was performed successfully.

Coronary Subclavian Steal Syndrome is a rare but significant pathology. It is important for Emergency physicians to consider it as a differential in patients with history of CABG and suggestive clinical features. A Computed Tomography (CT) Angiogram or Aortogram should be performed, and Vascular Surgery should be activated early for timely intervention.