Thumbnail image of: Atrial Septal Defect: Illustration

Atrial Septal Defect

What is an atrial septal defect?

An atrial septal defect is a hole between the upper 2 chambers of the heart. The size of the hole can be very small or it may be more than an inch in diameter. It is a birth defect, also called a congenital heart defect.

The heart has 4 sections, or chambers. The upper chambers are called atria, and the lower chambers are called ventricles. The wall between the right and left atria is called the atrial septum. Normally, blood flows from the right atrium into the right ventricle, and the right ventricle pumps it to the lungs. When there is a hole in the atrial septum, the left atrium pushes blood into the right atrium. The extra blood increases the heart’s workload. It also increases the flow of blood to the lungs.

What is the cause?

There are different types of atrial septal defects. They can be in different places on the atrial wall, and they can be different sizes:

  • Babies normally have a small hole in the atrial septum (called a foramen ovale) that allows blood to flow between the atria before birth. Before birth, a baby’s blood does not need to go through the lungs to pick up oxygen because the baby gets oxygen-rich blood from the mother. After birth, increased blood pressure on the left side of the heart normally forces a flap to close over the hole to seal it. If the flap does not seal, it is called a patent foramen ovale. It is not known why PFOs do not seal after birth in some people.
  • Other holes in the atrial wall may happen because the baby’s heart does not form properly.

Heart defects may be inherited, which means that that they are passed from parents to children through their genes. Genes are inside each cell of your body. They contain the information that tells your body how to develop and work.

What are the symptoms?

If the defect is mild, there may be no symptoms. Many people live their entire lives with a small atrial septal defect and do not know they have it. It may be found only when they are being tested for something else. Many defects cause a whooshing sound, called a murmur, as blood moves through the heart. Healthcare providers can hear the murmur with a stethoscope.

Large defects may cause symptoms. The extra blood flow through the lungs may increase the blood pressure in the lungs. Over time, this may cause heart failure. Symptoms may include:

  • Shortness of breath
  • Faster breathing rate
  • Cough
  • Feeling tired all the time
  • Swollen legs or ankles
  • Fast or irregular heartbeat
  • Fever or coughing up mucus

Sometimes blood clots form inside the blood vessels. Clots can break into pieces and float in the bloodstream and through the hole in the heart. If they block a blood vessel, the result can be a heart attack, stroke, loss of vision, or other problems.

How is it diagnosed?

Your healthcare provider will ask about your symptoms and medical history and examine you.

Tests may include:

  • Chest X-ray
  • An ECG (also called an EKG or electrocardiogram), which measures and records the heartbeat
  • Echocardiogram, which uses sound waves (ultrasound) to see how well the heart is pumping

You may have other tests to check for possible causes of your symptoms.

How is it treated?

Your healthcare provider will advise treatment based on the symptoms and size of the defect.

A small defect may never cause any symptoms or problems. It may close on its own during the first years of a child’s life. If a very small amount of blood flows through the hole, there may be no benefit to having the hole closed.

In general, it is best to close large defects at a younger age before the heart or lungs are damaged.

Two types of surgery may be done to close the defect:

  • Heart catheterization, which uses a small tube called a catheter inserted into a blood vessel, dye, and X-rays to look at the blood vessels and heart. The healthcare provider will use tools put through the catheter to repair the defect. The hole may be closed by sewing it, patching it with a small piece of tissue from another part of the heart, or by plugging the hole with a small metal or plastic device.
  • Open heart surgery to close the defect may be needed if it is large or if there are other heart defects.

How can I take care of myself?

If you have an atrial septal defect and no symptoms, get regular checkups with your healthcare provider. Your provider may want you to have regular follow-up visits with a specialist in congenital heart disease.

Ask your healthcare provider if you should take antibiotics to prevent infection when you are going to have dental work or procedures that involve the rectum, bladder, or vagina.

Ask your healthcare provider:

  • How and when you will hear your test results
  • How long it will take to recover
  • If there are activities you should avoid
  • How to take care of yourself at home
  • What symptoms or problems you should watch for and what to do if you have them

Make sure you know when you should come back for a checkup. Keep all appointments for provider visits or tests.

Developed by RelayHealth.
Adult Advisor 2015.1 published by RelayHealth.
Last modified: 2014-12-08
Last reviewed: 2014-12-08
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright ©1986-2015 McKesson Corporation and/or one of its subsidiaries. All rights reserved.

Patient Portal

myTuftsMed is our new online patient portal that provides you with access to your medical information in one place. MyTuftsMed can be accessed online or from your mobile device providing a convenient way to manage your health care needs from wherever you are.

With myTuftsMed, you can:

  1. View your health information including your medications, test results, scheduled appointments, medical bills even if you have multiple doctors in different locations.
  2. Make appointments at your convenience, complete pre-visit forms and medical questionnaires and find care or an emergency room.
  3. Connect with a doctor no matter where you are.
  4. Keep track of your children’s and family members’ medical care, view upcoming appointments, book visits and review test results.
  5. Check in on family members who need extra help, all from your private account.


Your privacy is important to us. Learn more about ourwebsite privacy policy. X