To understand why you need surgery and what the surgeon will be doing, it is helpful to understand how your heart works and what happens when heart arteries become clogged.

The Healthy Heart
The heart is about the size of both of your fists put together. It constantly pumps blood through your body. Because it never stops working, the heart muscle must have lots of oxygen-rich blood. Your heart gets this blood from your coronary arteries.

You have two coronary arteries: the right coronary artery and the left coronary artery. The left divides again into the left anterior descending artery and the circumflex artery. These branches continue to divide into smaller arteries, supplying every portion of the heart muscle with oxygen-rich blood.

In the healthy heart, blood flows through these arteries smoothly, providing the heart muscle with all the oxygen and nutrients it needs. Even during activity, when the heart needs more oxygen, healthy arteries are able to deliver it.

Blocked Arteries
If fat and calcium collect in the artery walls (this is called "plaque"), blood flow will decrease because the arteries get narrower. If an artery becomes too narrow, the heart muscle may not be able to get the oxygen it needs. This can result in a "heart attack".

Coronary Artery Bypass Surgery
You are having coronary artery bypass surgery because one or more of your coronary arteries is narrowed or blocked. In this surgery, another blood vessel ("graft") is used to go around, or bypass, the block in your artery, providing your heart muscle with new blood flow.

These blood vessel grafts are usually taken from the veins in your legs (saphenous veins), one of the arteries in your chest wall (usually the internal mammary artery) or from an artery in your arm. If leg grafts are used, an incision will be made down the inside of your leg (calf, thigh, or both) to obtain the veins. The removal of these blood vessels does not usually affect blood flow. Depending on a variety of factors, our surgical team may use a minimally invasive technique to remove this vein.

During the surgery, an incision is made down the middle of your breastbone (sternum), to expose the heart. Then your heart is cooled and stopped. While your heart is stopped, the normal work of the heart and lungs is done by the heart-lung bypass machine.

The blocks in your arteries are then "bypassed" using the removed vessels as new pathways for blood flow. After the surgeon is sure the new vessels are working, your heart is allowed to restart and the heart-lung bypass machine removed. Then, your chest will be closed.

Some operations are performed without the use of the heart-lung bypass machine. Medical conditions dictate the use of the heart-lung bypass machine and are made at the surgeon’s discretion.

The surgery usually takes about three to five hours.

What Are Heart Valves?
Your heart has four compartments, two on the right and two on the left. The compartments on the right side of your heart pump blood to the lungs. The compartments on the left side pump blood to your body. Each of these compartments has a "gate," or valve, that keeps blood flowing in the right direction.

On the right side are the tricuspid and pulmonic valves. On the left are the mitral and aortic valves. As the heart muscle pumps, blood flows from compartment to compartment. The valves open, allowing blood to flow into the next compartment and then they close in order to prevent blood from going back the wrong way.

Problems with Heart Valves
Problems with one of these valves may disrupt blood flow not only through the heart but also through the lungs and body. There are many possible causes for problems with valves. A valve defect may be present at birth. Certain diseases can cause damage or destruction of the valves. Normal aging can also cause valves to weaken or to get too hard.

A valve may have become so stiff (or hard) that instead of opening easily it makes it harder for blood to flow forward. This is called stenosis. The valve may also have become weakened or stretched so that instead of closing, blood is able to flow backwards. This is called regurgitation.

In either case, your heart has to work a lot harder to pump the same amount of blood to the body. Whether or not you need surgery depends on how badly your valve is damaged and how ill you are.

Correcting Heart Valve Problems

Depending on the type of problem, your valve may either be repaired or replaced.

Repairs
A stiff (stenotic) valve may be repaired by separating the stiff parts of the valve to make it open more easily.

A leaky (regurgitant) valve may need some strengthening or tightening up.

Replacement
Your valve may be replaced with either a mechanical valve or a tissue valve.

A mechanical valve is made from artificial materials. If you have a mechanical valve placed, you will need to take daily medicine to prevent clots.

A tissue valve is a valve taken from either human donors or one that is made from animal tissue. Tissue valves do not last as long as mechanical valves, but may not require daily medicine to prevent clots.

Discuss with your doctor what type of valve is recommended for you. Be sure to ask any questions you may have about it.

Valve Surgery
During valve surgery, an incision is made down the middle of your breastbone (sternum). Once your chest is open, your heart is cooled and stopped. During this time, the normal work of the heart and lungs is taken over by the heart-lung bypass machine.

Your valve is then replaced or repaired. After the surgeon is sure the new valve is working, your heart will be restarted and you will be removed from the heart-lung bypass machine. Your chest will then be closed using wire to close the bone and regular stitches to close your skin.

The surgery usually takes about three to five hours.