It was not that long ago that the phrase "open-heart surgery" would spark fear in most people.

Now coronary artery bypass graft surgery is one of the most common surgical procedures carried out in North America. Well over half a million bypass operations are performed on the continent every year. It remains one of the gold standard surgical treatments for coronary artery disease.

Bypass surgery is performed on patients to improve the flow of blood to the heart. That flow can be severely restricted by atherosclerosis — the buildup of plaque in the arteries leading to the heart.

Coronary arteries deliver a constant supply of blood and oxygen to your heart muscle. When one or more of these arteries becomes narrowed or blocked, the flow of blood and oxygen is reduced, which damages the heart muscle.

What causes coronary artery disease?

If you eat high-fat foods, don't exercise and smoke a lot, your risk of developing coronary artery disease will be higher than most people. But that doesn't necessarily mean you will get it. You could appear to be super fit, like running guru Jim Fixx and still develop heart disease.

Lifestyle is a contributing factor. So is your genetic makeup.

How do I know if I am a candidate for bypass surgery?

You may need bypass surgery if:

• You experience chest pains during light exercise or while at rest.
• You have more than one diseased artery that carries blood and oxygen to the heart.
• Your left ventricle — the heart's main pump — is not working properly.
• A previously treated artery has narrowed again.

Is bypass surgery my only option?

No. You could be a candidate for angioplasty — temporarily inserting and expanding a tiny balloon into your blocked artery in an attempt to widen it. Angioplasty is usually combined with the implantation of a small metal coil called a stent in the clogged artery. The goal is to help prop it open and reduce the chance of the artery narrowing again.

Angioplasty is also used during a heart attack to quickly open a blocked artery, which can limit damage to the heart muscle.

How is bypass surgery done?

You are put under a general anesthetic and your chest is opened up. Surgeons will bypass the blocked arteries by harvesting healthy veins from your leg, arm, chest or abdomen and connecting them to the other arteries in your heart. This allows the blood to bypass the diseased or blocked area.

The incision is normally about 15 centimetres long, leaving a very noticeable scar on your chest. However, new developments in robotic technology are allowing surgeons to perform minimally invasive coronary bypass surgery. On May 4, 2007, surgeons in London, Ont., used a da Vinci surgical robot to perform a bypass operation without opening up the patient's chest. The surgeons were able to do the procedure by making four one-centimetre long incisions.

Minimally invasive surgery reduces the time a patient has to stay in hospital from up to seven days to one or two. It also reduces recuperation time.

What happens during surgery?

Usually, your heart is stopped while surgeons work on it. You are hooked up to a heart-lung machine for much of the three to six hours that you are under the knife.

Surgeons attach a section of healthy blood vessel above and below the blocked artery. They do this for each of the blocked arteries. When the heart is restarted, the blood flows through the new vessel, bypassing the diseased artery.

Some patients are candidates for off-pump or beating-heart surgery. Your heart is not stopped during this procedure. Instead, surgeons use special equipment to stabilize the region of the heart they are working on. The benefits of off-pump surgery include less stress to the heart because you are not hooked up to the heart-lung machine, a quicker recovery and less time in the hospital.

It is a fairly new procedure — the first off-pump bypass operation was carried out in 1996 at the Cleveland Clinic in the U.S.

Whether you undergo traditional bypass surgery or off-pump bypass surgery, you will wake up in the recovery room or the intensive care unit.

Does bypass surgery cure coronary artery disease?

No. It treats the underlying condition — but if you don't alter your lifestyle, your chances of re-clogging your arteries are fairly high. The older you are, the higher your risk of recurrence.

What can I expect after surgery?

You can expect to feel a lot better. Most people report significant improvement in their symptoms. You will have more energy and will likely remain symptom-free for several years. However if you don't take your medication, quit smoking, reduce your cholesterol levels, maintain a healthy weight, control your blood pressure, manage your diabetes and exercise, your chances of re-clogging your arteries will increase.

You may also experience mood swings after heart surgery as well as a loss of appetite and constipation. You will likely feel some muscle pain or tightness in the shoulders or upper back and swelling in the area from which the healthy vessels were harvested. These side effects should go away in four to six weeks.