Aortic valve facts for kids

Quick facts for kids Aortic valve
A front view of the heart showing the aortic valve.
A closer look at the aortic valve.
Latin	valva aortae

The aortic valve is a very important part of your heart. Think of it as a one-way door between the heart's main pumping chamber (the left ventricle) and the body's biggest artery, the aorta. It is one of the four valves in the heart that control how blood flows.

The aortic valve's job is to open wide to let blood out to the rest of your body and then snap shut to stop it from flowing backward into the heart. Most people have an aortic valve with three little flaps, called cusps. However, about 1–2% of people are born with a valve that has only two flaps (bicuspid aortic valve).

How the Aortic Valve is Built

The aortic valve is made of three strong, thin flaps of tissue. These flaps are also called cusps or leaflets. Because of their shape, they are sometimes called semilunar valves, which means "half-moon shaped."

When the valve is closed, these three cusps fit together perfectly. This stops blood from leaking back into the heart after it has been pumped out.

Behind each cusp is a small pocket called an aortic sinus. Two of these sinuses are very special because they are the starting point for the coronary arteries. The coronary arteries are the blood vessels that supply the heart muscle itself with the oxygen-rich blood it needs to keep pumping.

This drawing shows the heart's valves from above. The aortic valve ("Ao") is behind the pulmonary valve ("PA").

What Does the Aortic Valve Do?

This video shows a real aortic valve opening and closing in a pig's heart.

Your heart beats in a rhythm of squeezing and relaxing to pump blood.

• When your heart's left ventricle squeezes (this is called systole), the pressure inside it builds up. Once the pressure is higher than in the aorta, the aortic valve pushes open. This allows a big rush of oxygen-rich blood to flow out into the aorta and travel to every part of your body.

• When the ventricle finishes squeezing and starts to relax, the pressure inside it drops quickly. The blood in the aorta naturally tries to flow backward, but this movement pushes the valve's cusps shut. This closing action makes part of the "dub" sound you hear in a heartbeat. This sound is known as the A₂ component of the second heart sound (S₂).

When the Valve Doesn't Work Right

A healthy aortic valve is key to a healthy body. If it doesn't work properly, the heart has to work much harder, which can lead to problems. This can make a person feel tired, weak, or out of breath when they are active.

A Leaky Valve (Aortic Regurgitation)

Sometimes, the valve doesn't close tightly. This is called aortic regurgitation or insufficiency. It means that after the heart pumps, some blood leaks backward into the left ventricle. This forces the heart to pump the same blood twice, making it work overtime. Over a long time, this can cause the heart to get bigger and weaker.

A Narrow Valve (Aortic Stenosis)

Another problem is when the valve becomes stiff and narrow, a condition called aortic stenosis. This can happen if calcium builds up on the valve over many years. A narrow valve doesn't open all the way, so the heart muscle has to squeeze much harder to push blood through the small opening. This can also cause the heart muscle to become too thick.

A microscope view of an aortic valve that has become thick and weak.

Causes of Valve Problems

Valve problems can be caused by different things. Some people are born with a valve that has only two cusps instead of three (a bicuspid aortic valve), which can wear out faster. Other causes include infections like rheumatic fever or damage that happens slowly over a person's life.

How Doctors Fix Aortic Valves

When an aortic valve is not working well, doctors have ways to fix it. The two main choices are to repair the valve or replace it with a new one.

Aortic Valve Repair

If possible, doctors will try to repair a person's own valve. This involves carefully reshaping the valve's flaps so they can open and close properly again. This is often done for leaky valves.

Aortic Valve Replacement

If the valve is too damaged to be repaired, it can be replaced. Doctors remove the old valve and put a new one in its place.

• Surgical Aortic Valve Replacement (SAVR) is a type of open-heart surgery to replace the valve.
• Transcatheter Aortic Valve Replacement (TAVR) is a less invasive method. A new valve is guided through a thin tube, called a catheter, through a blood vessel to the heart.

Types of New Valves

There are two main kinds of artificial heart valves:

• Mechanical valves are made of strong materials like carbon and metal. They are very durable and can last a lifetime. People with these valves usually need to take medicine to prevent blood clots.
• Tissue valves are usually made from animal tissue (often from a pig or cow). They work very much like a natural valve. They may not last as long as mechanical valves but often don't require the same long-term medicine.

In some cases, a donated human valve (homograft) or even the patient's own pulmonary valve (in a surgery called the Ross procedure) can be used.

Checking the Valve's Health

To find out if an aortic valve is working correctly, doctors use several tools:

• Listening with a Stethoscope: A doctor can listen to the heart. Unusual sounds, like a "murmur," can be a sign of a valve problem.
• Echocardiogram: This is the most common test. It's like an ultrasound for the heart. It uses sound waves to create a moving picture of the heart and valves. This shows doctors exactly how well the valve is opening and closing.
• Other Scans: Sometimes, doctors might use other imaging tests like an MRI or CT scan to get a more detailed look at the valve and the aorta.

Additional images

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  A model of a replacement heart valve made from biological tissue.

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  A diagram of the chest showing the location of the heart's valves. "A" marks the aortic valve.

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  A close-up view of an aortic valve.