The most common causes of myocardial ischemia and myocardial infarction early after coronary artery bypass grafting surgery are early graft occlusion/thrombosis or occlusion/ thrombosis of coronary arteries due to advanced coronary heart disease. We describe a case of postoperative myocardial ischemia due to an uncommon and quickly reversible cause: mechanical compression of a vein graft by a 19F flexible silicone mediastinal drainage tube.