If you have coronary artery disease (CAD), in which one or more of the main blood vessels feeding your heart is blocked, you may be facing coronary artery bypass surgery. A desire to improve outcomes after surgery and advances in technology have led surgeons to perform coronary artery bypass surgery without cardiopulmonary bypass, called off-pump bypass or "beating heart" surgery. Traditionally, coronary artery bypass surgery is performed with the assistance of cardiopulmonary bypass. The heart-lung machine allows the heart’s beating to be stopped, so that the surgeon can operate on a surface which is blood-free and still.

The heart-lung machine maintains life despite the lack of a heartbeat, removing carbon dioxide from the blood and replacing it with oxygen before pumping it around the body. The heart-lung machine has saved countless lives. Off-pump coronary arterybypass surgery differs from traditional coronary artery bypass surgery, because the heart-lung machine is not used. Rather than stopping the heart, technological advances and new kinds of operating equipment now allow the surgeon to hold stabilize portions of the heart during surgery. With a particular area of the heart stabilized, the surgeon can go ahead and bypass the blocked artery in a highly controlled operative environment. Meanwhile, the rest of the heart keeps pumping and circulating blood to the body. Off-pump coronary artery bypass surgery may be performed in certain patients with coronary artery disease. With present technology, all arteries on the heart can be bypassed off-pump.

It may be ideal for certain patients who are at increased risk for complications from cardiopulmonary bypass, such as those who have heavy aortic calcification, carotid artery stenosis, prior stroke, or compromised pulmonary or renal function. Not all patients are a candidate. The selection of patients who undergo off-pump surgery is made at the time of surgery when the patient's heart and arteries are evaluated more closely. The aims of off-pump bypass surgery is to decrease the morbidity of coronary artery bypass surgery, such as stroke, renal failure and need for blood transfusion. Also of great interest is the possibility that the off-pump approach may lessen the risk of what are called cognitive changes that have been seen in many patients who underwent CABG with cardiopulmonary bypass. These short-term changes include memory loss, difficulty thinking clearly and problems concentrating for lengthy periods. They usually improve over the months following surgery`