Coronary artery bypass surgery is an operation to improve the flow of blood to the heart muscle in people whose coronary arteries are severely narrowed or blocked.
Coronary arteries are blood vessels that carry oxygen and nutrients to the heart.
The operation involves taking blood vessels from other parts of your body and attaching them to the coronary arteries beyond the blockage. If more than one artery is blocked, you may need more than one bypass. The location and degree of coronary artery blockages are determined before surgery by using a procedure called heart catheterization, or coronary angiogram. This procedure provides an outline, like a road map, of the arteries of the heart. If you smoke, quit.