Ischemia induced by coronary steal through a patent mammary artery side branch: a role for embolization.

Non-occlusion of the internal mammary artery side branches may cause ischemia due to flow diversion after coronary artery bypass grafting. The authors present the case of a 67-year-old man with recurrent angina after undergoing myocardial revascularization with a left internal mammary artery to left anterior descending bypass. He presented with impaired anterior wall myocardial perfusion in the setting of a patent left internal mammary artery side branch. Effective percutaneous treatment was carried out through coil embolization, with improved flow and clinical symptoms, confirmed through ischemia testing. Coronary steal through a patent mammary artery side branch is a controversial phenomenon and this type of intervention should be considered only in carefully selected patients.