Morphological abnormalities related to the surgical treatment of ischemic heart disease are discussed. Catheterization, angioplasty, or intraarterial thrombolysis may lead to perforation, endothelial injury, thrombosis, or dissection of the artery; endothelial injury results in intimal thickening. Laser angioplasty produces a localized area of thermal and acoustic injury that may heal without luminal compromise. Endarterectomy may be followed by thrombosis or exuberant muscular proliferation. Changes in saphenous veins used as coronary artery bypass grafts are mainly thrombotic in the early postoperative period; years after operation failure usually is due to some combination of fibromuscular intimal thickening, atherosclerosis, thrombosis, and dissection. Surgically resected areas of myocardial dysfunction show one or more abnormalities of hypertrophy, myocytolysis, fibrosis, and endocardial thickening. Perioperative ischemic injury is manifested by contraction band necrosis or coagulation necrosis. Excised arrhythmogenic foci have mixtures of normal and abnormal myocytes. The pathological features of pacemakers and circulatory assist devices include thrombosis, embolism, infection, dissection, and mechanical failures.