Common heart valve diseases

Some of the more common diseases affecting the heart valves include:

Aortic stenosis (AS)

This is caused when the aortic valve hardens, making the valve narrower and reducing the flow of blood. This means that the heart needs to work harder to pump blood around the body. Due to this extra workload, the muscle of the lower left chamber of the heart thickens, and the chamber may eventually become enlarged. If not treated, this can lead to heart failure and other health problems.

Mitral valve regurgitation (MR) or prolapse

This is where the mitral valve becomes weak and stretches out, which can mean blood flows in the wrong direction. Often the amount of blood that flows back is small, and so may not cause any symptoms. If the condition is more serious, blood can’t move through your heart or to the rest of your body properly, which can make you feel tired or out of breath.

Tricuspid valve disease (TS or TR)

The tricuspid valve can become diseased, causing blood flow to decrease or flow back in the wrong direction. Two types of tricuspid valve disease include:

• Tricuspid regurgitation, where the valve is leaky or doesn’t close properly. This can allow blood to leak backwards through the valve.
• Tricuspid stenosis, where the valve becomes stiff and does not open enough. This can cause the flow of blood to decrease.

Bicuspid aortic valve (BAV)

This is the most common congenital (ie. present from birth) heart abnormality. It affects 1-2% of the population. Some people may not experience any symptoms, while for others it can be a serious condition. Heart valves have flaps of tissue called cusps, which open and close when the heart beats. These ensure that the blood flows in the right direction. The aortic valve normally has three cusps, but a bicuspid valve has only two. A bicuspid aortic valve can cause problems including:

• Narrowing of the aortic valve (aortic valve stenosis)
• Backward flow of blood through the valve (aortic valve regurgitation)
• An enlarged aorta, which increases the risk of a tear in the lining of the aorta

Endocarditis

This is an infection of the lining of the heart, which can lead to valve damage. It is usually caused by bacteria, but can also be caused by fungi or other germs. These can come from another part of the body, such as the mouth, travel through the bloodstream and attach to damaged areas of the heart. If not treated, endocarditis can damage the heart valves. People with heart valve disease, or with a replacement valve, may be at higher risk.