The four valves that control the one-way ?ow of blood through the chambers of your heart open and close with your every heartbeat. These delicate structures deep inside your heart are critical to the meas- ured passage of about 100 gallons of blood every hour. Responding to pressure changes behind and ahead of them, the lea?ets (or cusps) of each valve must open fully and close tightly to keep blood moving
properly.
If the valves are malformed or not fully functioning, two types of problems can interfere with the one-way ?ow. If a valve fails to open fully, impeding the forward ?ow of blood, the condition is called steno- sis. Since the narrowed heart valve may limit blood ?ow, this can cause symptoms from inadequate circulation. Stenosis is usually the result of the lea?ets thickening, stiffening, or even fusing together. Over time, the heart has to work harder to push blood through the valve, which can damage the heart muscle and enlarge the heart chamber.
If a valve cannot close completely to seal off back-?ow, the problem is called regurgitation (also known as insuf?ciency or incompetence). Because blood is leaking backward, the heart chamber behind the valve tends to enlarge and may pump less ef?ciently.
Your heart has remarkable ability to adapt to and compensate for valve problems. Often a doctor can detect an abnormality in one of your valves by listening to your heart sounds through a stethoscope. The dis- ruption in ?ow causes some audible blood turbulence, called a heart murmur. Because the heart has adapted, you may not have any symptoms and your heart may function quite normally for decades. But if, over time, your heart can no longer compensate, then symptoms such as shortness of breath can develop. It is important to have the problem diag- nosed so it can be treated before permanent damage is done to heart muscle.