Coronary Subclavian Steal Syndrome in a 73-Year-Old Woman Presenting with Angiographically Confirmed Subclavian Artery Stenosis Proximal to the Left Internal Mammary.

BACKGROUND Coronary subclavian steal syndrome (CSSS) is an uncommon condition in which a high-grade stenosis of the subclavian artery proximal to an internal mammary artery bypass graft results in retrograde blood flow of the bypass graft. This report is of CSSS in a 73-year-old woman who presented with ventricular tachycardia and angiographically confirmed subclavian artery stenosis proximal to the left internal mammary artery (LIMA) bypass graft 3 years following coronary artery bypass grafting (CABG). CASE REPORT The patient was a 73-year-old woman with a past medical history of multivessel coronary artery disease, found on preoperative evaluation. She underwent 2 vessel CABG in 2018. She was found to have ischemic cardiomyopathy, ejection fraction of 30% to 35% despite revascularization, and an implantable cardiac defibrillator (ICD). Three years following uncomplicated CABG, the patient presented with angina and sustained ventricular tachycardia; ICD therapy was unsuccessful. Ischemia was the etiology of the sustained ventricular tachycardia, and the patient underwent cardiac catheterization, demonstrating high-grade subclavian artery stenosis proximal to the LIMA bypass graft. Intervention of the 80% lesion of the native left anterior descending artery was done with placement of a 2.75×16-mm drug-eluting stent. The patient responded well to treatment, with no subsequent ventricular tachycardia on outpatient follow-up. CONCLUSIONS This report has shown that in patients who present with symptoms of acute coronary syndrome and a history of CABG involving the LIMA, the possibility of CSSS should be considered and investigated by coronary artery imaging so that diagnosis and management are not delayed.