Coronary artery bypass surgery is a procedure that detours (or bypasses) blood around a blocked section of one or more coronary arteries. It is also called coronary artery bypass grafting or CABG (pronounced "cabbage").
Coronary arteries are the blood vessels that supply the heart with oxygen and nutrients. You have several coronary arteries. They are named for their location. For example, your doctor may speak of the left main coronary artery, left anterior descending artery or the right coronary artery.
Coronary artery disease is any illness that damages these arteries. Coronary artery disease is often called "coronary atherosclerosis." Atherosclerosis is the narrowing of arteries caused by the buildup of fat and cholesterol. This buildup is called plaque. Plaque can decrease the amount of blood that reaches the heart. The plaque can tear and cause a blood clot. The clot can block your artery and stop the flow of blood to your heart. This can cause a heart attack.