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What Is an Atrial Septal Defect (ASD)?

An atrial septal defect is an opening or hole in the wall that sits between the heart’s two upper chambers. The heart’s upper chambers are called the right and left atria. Some people refer to atrial septal defect as "having a hole in your heart."

Atrial septal defect (ASD) is a congenital disease. This means that children and babies who have ASD have it as soon as they’re born. ASD doesn’t develop later in life. If you have a hole in the wall of the lower two chambers of your heart, you have a ventricular septal defect.

Some babies have an ASD but don’t have any other heart problems. Other babies with ASDs have other congenital heart defects. Girls are two times more likely to have ASDs than boys, but doctors don’t know why.

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Types of Atrial Septal Defects

There are a few different kinds of ASDs. The type of ASD your baby has will depend on where the hole inside her heart is located:

  • Secundum ASD is when your baby has a hole in the middle of her atrial septum (the wall that separates the right and left atria inside the heart).
  • Primum ASD is when your baby has a hole in the lower part of her atrial septum (wall). The lower part of the atrial septum is close to the tricuspid and mitral valves.
  • Sinus venosis is when your baby has a hole in the upper part of her atrial septum (wall). The upper part of the atrial septum is between the heart’s coronary sinus and left atrium (chamber).
  • Coronary sinus ASD is when your baby has a hole in the wall that’s between the coronary sinus and left chamber (atrium).

Patent Foramen Ovale (PFO)

Many people confuse ASDs with another kind of heart defect called patent foramen ovale (PFO). A PFO is an opening between your heart’s right and left atria (or chambers). But a PFO is not a type of ASD. This is because people who have PFOs aren’t missing any of their septal tissue. (Septal tissue is a type of tissue that makes up the inside of the heart wall). Instead, their septal tissue just didn’t close properly when their heart was developing.

What Causes ASD?

Babies start to develop hearts during the first eight weeks of pregnancy. In a developing embryo, the heart starts out as a hollow tube that splits into four chambers. Walls called septa separate each of these chambers. These walls often have openings as a fetus grows. But the openings usually close just before or after birth. If these openings don’t close, this means the septum has a hole in it. Having a hole inside your heart is called an ASD.

Some congenital heart problems are passed down in families through genes. Most ASDs are caused by random mutations in a baby’s genes. In other words, ADS happen by chance. Doctors don’t know why ASD happens.

Symptoms of Atrial Septal Defects

Luckily, many children with ASDs have no symptoms and are healthy. If the hole inside your baby’s heart is large, she may have symptoms. These can include the following:

  • getting tired easily
  • growing slowly
  • having fast breathing
  • having shortness of breath
  • getting respiratory infections often
  • having abnormal heart rhythms (arrhythmias)

Because these symptoms are common to lots of other diseases, many people confuse ASD symptoms with other conditions. Be sure to take your child to a doctor for a correct diagnosis.

Atrial Septal Defects, Migraines, & Strokes

Some older children and adults who have ASDs get migraine headaches. But doctors don’t know if ASDs cause these migraines.

Older children and adults with ASD may also have a higher chance of getting strokes. However, doctors don’t fully understand the relationship between ASD and strokes. Doctors don’t think that closing the hole or taking anticoagulants (blood thinners) will lower adults’ chances of getting strokes.

How Is ASD Diagnosed?

Many doctors will listen to your child’s heart using a stethoscope. One of the first signs of ASD is having a heart murmur. Heart murmurs sound different from a normal heartbeat. This is because blood is flowing abnormally through the heart.

Your child may also need to visit a pediatric cardiologist (heart doctor) to find out exactly what’s wrong. A pediatric cardiologist has special training in caring for children with heart problems.

Doctors can also use special tests to find out if your child has ASD. These tests include:

  • Chest X-ray. Chest X-rays show pictures of your child’s heart and lungs. Doctors sometimes use chest X-rays to diagnose ASD because an X-ray will show if your child’s heart is larger than normal (an enlarged heart). Chest X-rays can also show changes in your child's lungs. This is because ASD causes blood to flow differently than it normally does.
  • Electrocardiogram (ECG). An electrocardiogram (or ECG) shows electrical activity inside your child’s heart. ECGs can also find abnormal heartbeats (called arrhythmias) and can also see if your child’s heart muscle is stressed. ASDs can cause both arrhythmias and heart stress.
  • Echocardiogram (echo). An echocardiogram (or echo) uses sound waves to show a picture of your child’s heart and heart valves while they’re moving. Echo tests can diagnose ASDs because they show how much blood flows through the hole in your child’s atrial septum. Echo tests can also see how big this hole is.
  • Cardiac catheterization. In this test, doctors use a thin, flexible tube called a catheter and place it close to your child’s heart. Doctors use contrast dye to get very clear pictures of your child’s heart. In some children, doctors also use cardiac catheterization to close your child’s ASD.


After a doctor diagnoses your child with ASD, your child’s doctor will check to see if the hole is closing on its own. If the hole hasn’t closed by the time your child starts school, your child will usually need treatment. Doctors will look at the size of the hole to help you decide whether or not your child needs treatment.

Treatments for ASD can include the following:

  • Medicine. Many children with ASD don’t have symptoms and don’t need medication. But it still might be a good idea for some children to take it. Medicine can help some children's hearts work better. For example, water pills (diuretics) help a child’s heart work better by flushing extra fluid out of a child’s body through their kidneys.
  • Surgery. Your child may need surgery to fix their ASD. Surgeons use stitches or a special patch to close the hole inside your child’s heart wall. Your child will be asleep under general anesthesia. Our surgeons may use robotic surgery techniques to perform an ASD closure.
  • Device closure. Doctors use a small, flexible tube called a catheter along with another tool called a septal occluder. The doctor will carefully push the catheter through your child’s blood vessels all the way into her heart. Then, your doctor will use the septal occluder to stop blood from flowing through the ASD hole.

Atrial Septal Defects & Long-Term Health Problems

Over time, large ASDs can cause lung problems if the ASD isn’t treated. Extra blood passes through the hole in your child’s heart and then into your child’s lungs. This extra blood may hurt the tiny, delicate blood vessels inside your child’s lungs.

How Can I Help My Child With ASD?

All children who have ASD need to be under the care and supervision of a pediatric cardiologist. Most children who have the hole in their heart closed will live healthy lives. After your child’s hole is closed, the doctor may ask your child to take antibiotics. Taking antibiotics will help prevent your child from getting an infection inside her heart lining (bacterial endocarditis).

Children with ASDs usually stay very healthy if their hole is diagnosed and closed when they’re young. In these cases, children usually don’t need a lot of follow-up care.

If children with ASDs have health problems, it’s usually because doctors didn’t diagnose the ASD until the child was older. Older children and adults with ASD can also have health problems if their ASD was never closed. Older children can also have health problems if they had complications after the hole inside their heart was closed.

Some children get high blood pressure in their lungs. This is called pulmonary hypertension. If your child has pulmonary hypertension, she should get follow-up care at a hospital that specializes in congenital heart disease.

Talk with your child's doctor about any long-term health problems your child may have.

When Should I Call My Child’s Doctor?

You should call your child’s doctor if your child is showing new symptoms, or if her symptoms are getting worse. Symptoms to watch for include the following:

  • Your child is getting more and more tired.
  • Your child’s breathing is fast.
  • It’s hard for your child to breathe.
  • Your child has racing heartbeats or palpitations.

Important Things to Know About Atrial Septal Defects

  • An atrial septal defect is a hole or opening inside the heart. The hole is located in the wall that separates the heart’s two upper chambers (called the septum).
  • Symptoms of ASD can including getting tired easily, breathing quickly, feeling short of breath, growing poorly, having irregular heartbeats (arrhythmias), or getting respiratory infections often.
  • Atrial septum defects (holes inside the heart) can be large or small.
  • Some atrial septum defects (holes inside the heart) close on their own.
  • Doctors can treat and fix large atrial septum defects. They can also treat atrial septum defects that cause symptoms.
  • Most children who have their atrial septum defect treated will live long, healthy lives.

Next Steps

Finding out that your child has an atrial septal defect can be scary and overwhelming. Before you visit a doctor to talk about your child’s condition, keep these tips in mind:

  • Before your appointment, write down any questions you’d like your doctor to answer.
  • Know why you’re making the appointment and what you want to gain from the appointment.
  • After your child’s appointment is over, write down the names any new diagnoses the doctor gave your child. Also, write down the names of any new medications, tests, or treatments the doctor recommends.
  • If your doctor is prescribing a new medicine or treatment, know why. How will this medicine or treatment help your child? Be sure you know if the medicine has any side effects.
  • Ask if your child can get other types of treatment for ASD.
  • If your doctor is recommending a special test or procedure, know why. Be sure to learn about what the test results will tell you.
  • Know what could happen if your child doesn’t take medicine or get the test or procedure your doctor is recommending.
  • If your child will have a follow-up appointment, be sure to write down when and where the appointment will be. Write down the reason your child needs that follow-up appointment.
  • Know how to contact your doctor’s office after business hours. It’ll be important to contact your child’s doctor after hours if your child gets sick and you have questions or need help.