Spontaneous reversible spasm in an internal mammary artery graft causing acute myocardial infarction

Spontaneous spasm occurring in native coronary arteries in the absence of fixed atherosclerotic disease carries a generally favorable prognosis¹; only occasionally does it result in myocardial infarction. Spasm of saphenous vein and left internal mammary artery grafts has been demonstrated in the immediate postoperative period, and can result in hemodynamic collapse.^2,3 In addition, although rare, spasm of both saphenous vein and left internal mammary artery grafts presenting with recurrent angina pectoris several years postoperatively has been angiographically documented.^4,5 To our knowledge, late postoperative spasm in a bypass conduit has never been linked to transmural myocardial infarction. We recently studied a patient who sustained a transmural anterior myocardial infarction related to spontaneous reversible spasm of a left internal mammary artery graft.