The heart is generally thought of as having a right and left side. In reality, the heart is one organ and not divided into two separate organs. The heart is made up of four chambers, two on the right and two on the left. The chambers are known as atria and ventricles. Each side of the heart is composed of one atrium and one ventricle. The atria are the receiving chambers of the heart, receiving blood flowing back to the heart. The ventricles are the chambers of the heart that pump the blood out of the heart.
The valves of the heart are located within the chambers of the heart and are critical to the proper flow of blood through the heart. All of the valves, when functioning normally, act as one-way valves, allowing blood to flow either from one chamber to another, or allowing blood to flow out of the heart, in only one direction. The valves control the flow of blood through the heart by opening and closing during the contractions of the heart. The opening and closing functions of the valves are controlled by pressure differences generated within the heart, as well as some muscles located within the heart.
Heart valve disease occurs when a valve doesn’t work right. A valve may not open all the way. Or, a valve may have problems closing. If this happens, blood doesn’t move through the heart’s chambers the way it should.
If a valve doesn’t open all the way, less blood moves through to the next chamber. If a valve doesn’t close tightly, blood may leak backward. These problems may mean that the heart must work harder to pump the same amount of blood. Or, blood may back up in the lungs or body because it’s not moving through the heart as it should.
Stenosis occurs when a valve doesn’t open fully. The valve may have become hardened or stiff with calcium deposits or scarring. So, it’s hard to push open. Blood has to flow through a smaller opening, so less blood gets through the valve into the next chamber.
Insufficiency (also called regurgitation) results when the valve doesn’t close tightly. The valve’s supportive structures may be loose or torn. Or, the valve itself may have stretched or thinned. Blood may then leak back the wrong way through the valve.
During heart valve surgery, one or more valves are repaired or replaced. Repair means that the valve is mended to help it work better. Replacement means your diseased valve is removed and a new valve is inserted in its place. Whether a valve will be repaired or replaced can only be decided once surgery has begun. Your surgeon will talk with you about his or her plans for surgery and any other procedures you may need.
During valve repair, a ring may be sewn around the opening of the valve to tighten it. Other parts of the valve may be cut, shortened, separated, or made stronger to help the valve open and close right.
If a valve can’t be repaired, it may be replaced with a prosthetic valve. Two kinds of prosthetic heart valves are available:
Mechanical valves are created from man-made materials. Lifetime therapy with an anticoagulant (sometimes called a “blood thinner”) is needed when these types of valves are used. This medication prevents blood clots from forming on or around the valve.
Biological (tissue) valves are taken from pig, cow, or human donors. These valves don’t last as long as mechanical valves. But when tissue valves are used, long-term use of an anticoagulant often isn’t needed.
Your doctor will talk with you about choosing the best valve for you. Factors weighed include your age, your occupation, the size of your valve, how well your heart is working, your heart’s rhythm, your ability to take an anticoagulant, and how many new valves you need.
To get to your heart, one or more incisions must be made in your chest. For minimally invasive valve surgery, these incisions are most often much smaller than those made for traditional valve surgery. One of two types of incisions may be used. Which type your surgeon chooses depends on the location of the valve and the method of surgery used. Your surgeon will talk with you about which incision you will receive.
During valve surgery, your heart must not beat. To keep your blood flowing, it is passed through a heart-lung machine. This machine gives oxygen to your blood and pumps the blood back through your body. Your surgeon may choose to connect your body to the machine through the vessels in your heart or through vessels in your groin. Once the valve surgery is done, your heart and lungs take over again.
To reach the valve, an incision is made in your heart or aorta. If the valve can be mended, the needed repairs are done. If the valve must be replaced, part or all of the damaged valve and its supportive structures may be removed. The right-sized replacement valve is selected, positioned in the valve opening, and sewn firmly into place. The incision in your heart or aorta is closed. Your heart is then started so it beats on its own again.