Atrioventricular septal defect (AVSD)

What is AVSD?

Atrioventricular septal defect, also known as AVSD, is a large hole or holes in the wall between the chambers of the heart. There is only one valve, instead of two, between the upper and lower chambers. It can also be called atrioventricular canal (AVC) defect or endocardial cushion defect.

AVSD is a type of congenital heart disease, which means it’s something you’re born with. Most people with a small or repaired AVSD can live a normal healthy life.

There are two types of AVSD. One is a complete AVSD and the other is a partial AVSD.

If you have an AVSD, your heart needs to work much harder to pump blood around your body, causing the heart muscle to get bigger and weaker. If left untreated, AVSD can cause heart failure and high blood pressure in the lungs.

AVSD usually causes problems with your heart valves as it lets blood flow in the wrong direction. It can help to learn more about heart valves and how they work.

• Read more on how a healthy heart works.

Causes of AVSD

In most cases, we do not know why the heart has not developed normally. Research is looking at the causes of congenital heart disease. You may have an increased risk of AVSD if you have Down’s Syndrome.

• Read more information on congenital heart disease and causes.

Types of AVSD

There are different types of AVSD. The most common types are:

Complete AVSD

A complete AVSD is a hole between the right and left side of the heart. The hole occurs in the middle of the heart between the two upper pumping chambers (called atria) and the two lower pumping chambers (called ventricles). It also affects the valves that direct blood flow through the heart.

Partial AVSD

A partial AVSD is a hole that affects only the two upper chambers of the heart (called atria). It also affects the valves of the heart.

Usually there are two valves between the upper and lower chambers of the heart, one on the right and one on the left. In both types of AVSD, the heart valves do not form properly which leads to one ‘common valve’ instead of two. This is also called an atrioventricular valve. It is shared between the left and right sides of the heart.

Because the valves have not formed properly, this can cause the ‘common valve’ to not close fully, so blood can flow back (or leak) into the chambers. The heart has to work harder to pump blood around your body.

Signs and symptoms of AVSD

Babies with a complete AVSD usually show signs within the first weeks after birth. These include;

• breathing problems
• heart murmur (an extra, unusual sound in the heartbeat)
• weak pulse
• excessive sweating
• cyanosis (where the skin or lips turn blue or grey)
• poor appetite
• slow weight gain or weight loss
• tiring easily
• swelling of the legs or belly.

In partial AVSDs, symptoms may not show for months or even years. When they occur, they include;

• arrhythmia
• heart murmur (an extra, unusual sound in your heartbeat)
• weakness
• feeling sick
• lack of appetite
• finding it difficult to exercise
• shortness of breath
• swelling in the legs, ankles and feet
• chest pressure or pain.

Speak to your doctor if you have any of these symptoms.

Diagnosis of AVSD

AVSD might be diagnosed during pregnancy, soon after a baby is born, or in early childhood. Some people may be diagnosed with a partial AVSD in adulthood.

During pregnancy

An AVSD can be diagnosed with an ultrasound during pregnancy. However, an ultrasound can miss the AVSD if it is small.

After birth

During a routine check on a baby, the doctor might hear a whooshing sound through a stethoscope. This is called a heart murmur.

Seek medical help immediately if you notice any symptoms in a baby.

Treatment of AVSD

Surgery

An AVSD can only be repaired with surgery. When you will have surgery and what type depends on the type of AVSD, and your individual circumstances. Most repairs are done in childhood, but heart surgery in adulthood is common.

An AVSD repair involves working directly on your heart (also known as open heart surgery) to close the hole or holes in the heart. The common valve will be divided into separate right and left parts. It is common for one of the valves to allow some blood to flow back in the wrong direction (or leak) after repair. This will be monitored and treated if needed.

Following a repair, many people do not need any further medicines or surgeries. However, you may develop problems with the repaired hole or heart valves later in life. You may need surgery but your specialist team will discuss your options with you.

People who have had an AVSD repair may also experience abnormal heart rhythms (also known as arrhythmias). A pacemaker or other treatments might be needed.

Life with AVSD

If you have a repaired AVSD and are not showing any symptoms, you should be able to live a normal life. You will need to see your specialist team to check your if heart is working well. They will let you know how often they need to see you. It is very important to go to follow-up appointments, even if you feel fine.

Exercise

Most people with a repaired AVSD can exercise. However, you should speak to your doctor or nurse before starting or making changes to your exercise routine.

You should seek medical help immediately if you experience any symptoms like chest pain, breathlessness, palpitations or dizziness.

Endocarditis

This is a rare infection that causes inflammation of the valves and inner lining of the heart. People with congenital heart disease, such as an AVSD, have an increased risk of endocarditis. To reduce the risk of developing endocarditis, your doctor might recommend antibiotics after surgery.

You may need to take antibiotics before your dental appointments to reduce your risk of endocarditis. Speak to your doctor and dentist to see if you need to do this.

Family planning

If you have or had an AVSD, speak to your doctor about your risk for heart problems during pregnancy. For most women with a small or repaired AVSD, the risk of complications is low.

It's important to talk to your doctor before getting pregnant if you have a heart condition. If you are expecting a baby, ask your midwife or doctor about any concerns you have.

• If you have been told your child may have congenital heart disease, Tiny Tickers has more useful information.
  

Help and support

Your healthcare team are here to support you. You can ask them anything. It might feel uncomfortable or embarrassing to ask questions but most people feel much better once they do.

Here are some other ways you can get support.

• Read about the most commonly asked questions about congenital heart diseases. We talk about things like alcohol, mental health, preparing for surgery, and more.

• If you still have more questions, speak to our cardiac nurses on our Heart Helpline by phone, callback, email or online chat (Monday to Friday, 9am to 5pm).

• You can also speak to others with heart conditions by joining a support group or online community.