Heart valve disease
Valvular heart disease is any condition that disrupts the proper function of the valve. There are four valves in the heart which help keep blood flowing in a forward direction as the various chambers of the heart squeeze or fill. Normal heart valves open fully to allow blood to flow in a forward direction through the heart and close tightly to prevent blood from flowing backward.
There are two general types of valve disease. If the valve does not open properly, the forward flow is restricted. This is called stenosis. If the valve fails to close properly, backward flow is not prevented when the heart pumps. This is called regurgitation or insufficiency.
In either case, forward flow is reduced and symptoms such as breathlessness, weakness, dizziness and fainting can occur.