coronary artery bypass graft (CABG), open heart surgery in which a prosthesis or a section of a vein or internal mammary artery is grafted from the aorta onto one of the coronary arteries, bypassing a narrowing or blockage in the coronary artery. The operation is performed in coronary artery disease to improve the blood supply to the heart muscle and to relieve anginal pain. Coronary arteriography pinpoints the areas of obstruction before surgery. Under general anesthesia and with the use of a cardiopulmonary bypass machine, one end of a 15- to 20-cm prosthesis or a segment of saphenous vein from the patient’s leg is grafted to the ascending aorta. The other end is sutured to the clogged coronary artery at a point distal to the stoppage. The internal mammary artery may also be used as graft tissue. Usually double or triple grafts are done for multiple areas of blockage. After surgery, close observation in an intensive care unit is essential to ensure adequate ventilation and cardiac output. The systolic blood pressure is not allowed to drop significantly below the preoperative baseline, nor is it allowed to rise significantly, because hypertension can rupture a graft site. Arrhythmias are treated with medications or by electrical cardioversion. The patient is usually discharged within 5 to 8 days, unless complications occur.
