Coronary Subclavian Steal Syndrome Causing Myocardial Infarction

Coronary subclavian steal syndrome (CSSS) is a rare complication of the internal mammary artery (IMA) grafting in coronary artery bypass surgery. The technical definition is myocardial ischemia due to the reduced flow of blood, or flow reversal in the IMA graft. This in most cases results from hemodynamically significant proximal subclavian artery stenosis. The clinical presentation is variable and ranges from unstable angina to myocardial infarction, and in some cases, sudden cardiac arrest. CSSS is an entity that is hard to diagnose if one is not actively looking for it. The clinical diagnosis is often complicated, and the prevalence of the disorder is frequently underestimated. In this case presentation, we report a case of myocardial infarction that resulted from significant proximal subclavian artery stenosis.