Atrial Septal Defect (ASD)

What is Atrial Septal Defect (ASD)

An atrial septal defect is a hole in the heart. This hole is located in the thin tissue (septum) that separates the two upper chambers of the heart (right atrium and left atrium).

This hole is present at birth (congenital). A few minutes after birth, this hole normally closes so that blood is not able to go between the right atrium and left atrium.

Normally, blood from the right side of the heart is pumped to the lungs, where the blood has oxygen added to it (is oxygenated). The oxygenated blood from the lungs is then pumped to the left side of the heart.

From the left side of the heart, blood is pumped out to the rest of the body. When an ASD occurs, blood from the left atrium mixes with blood in the right atrium. The blood is then recirculated to the lungs and left side of the heart. In other words, the blood makes the trip twice.

An ASD makes the heart work harder by increasing the amount of blood in the right side of the heart. This causes heart overload and eventually weakens the heart’s ability to pump.

3 Interesting Facts of Atrial Septal Defect

1. Usually presents with exertional dyspnea, fatigue, cyanosis, and clubbing
2. Increased jugular venous pressure, pansystolic murmur that is best heard at apex, wide fixed split of S₂, ejection systolic flow murmur, and visible and palpable pulmonary artery pulsations
3. Differentiated with echocardiography, which allows identification of atrial septal defect

What are the causes?

The cause of this congenital condition is not known.

What are the symptoms of Atrial Septal Defect?

Symptoms of Atrial Septal Defect include:

• Tiredness or fatigue.
• Trouble breathing or shortness of breath.
• Irregular heartbeats (arrhythmias).
• An extra “swishing” or “whooshing” sound (heart murmur) that is heard when listening to the heart.

How is Atrial Septal Defect diagnosed?

Atrial Septal Defect is diagnosed based on the results of one or more of the following tests:

• Electrocardiogram, ECG. This records the electrical activity of your heart and traces the patterns of your heartbeat.
• Chest X-ray exam.
• Echocardiogram. There are two types that may be used:
  • Transthoracic echocardiogram (TTE). A TTE is very effective in detecting the two most common types of ASD, ostium primum or ostium secundum. It is not as sensitive in detecting a less common form of ASD, sinus venosus.
  • Transesophageal echocardiogram (TEE). A TEE is especially helpful in patients who have a thin or easily movable (mobile) septum, making ASD detection more accurate.
• MRI or CT scan.
• Cardiac catheterization. In this procedure:
  • A small tube (catheter) is passed through a large vein in your neck, groin, or arm.
  • Your cardiologist visualizes your heart defect, checks how well your heart is pumping, and checks the function of your heart valves.

How is this treated?

Treatment for Atrial Septal Defect depends on the size of the hole and the amount of blood that goes into the right atrium.

• No treatment is required if only a small amount of blood is moving back and forth (shunting) from the left to right atrium.
• Minimally invasive closure may be done depending on the type and location of the ASD. This treatment is done in a cardiac catheterization lab.
  • A catheter is inserted into a large blood vessel.
  • The catheter is advanced to the ASD in the heart.
  • A patch resembling an umbrella is threaded up the catheter and placed in the ASD hole.
  • The patch is then “opened up” to close off the hole.
• Open heart surgery may be necessary if minimally invasive closure cannot be done. In open heart surgery:
  • If the ASD is small, the hole can be closed with stitches.
  • If the ASD is large, a patch is sewn over the defect so the hole is closed.

Get help right away if:

• You experience unusual fatigue when you exert yourself.
• You have chest pain at rest or with exertion.
• You notice your fingertips or lips turning pale or blue.

Atrial Septal Defect in Children

An atrial septal defect (ASD) is a hole in the heart. This hole is located in the thin tissue (septum) that separates the two upper chambers of the heart, the right and left atrium. This hole is present at birth (congenital). A few minutes after birth, this hole normally closes so that blood is not able to go between the right and left atrium.

Normally, blood from the right side of the heart is pumped to the lungs, where the blood is combined with oxygen (is oxygenated). Then, the oxygenated blood from the lungs is pumped to the left side of the heart. From the left side of the heart, blood is pumped out to the rest of the body. When an ASD is present, blood from the left atrium mixes with blood in the right atrium. Then, the blood flows to the lungs and the left side of the heart, which means that the blood makes the trip twice. An ASD makes the heart work harder by increasing the amount of blood in the right side of the heart. This causes heart overload and eventually weakens the heart’s ability to pump.

What are the causes?

The cause of this congenital condition is not known.

What are the signs or symptoms?

Symptoms of this condition include:

• Mild to extreme tiredness (fatigue).
• Trouble breathing or shortness of breath.
• Sensations of fluttering in the chest due to irregular heartbeat (arrhythmias).
• An extra “swishing” or “whooshing” type sound (heart murmur) heard when listening to the heart.

How is this diagnosed?

This condition is diagnosed based on the results of one or more of the following tests:

• Electrocardiogram (ECG). This records the electrical activity of your child’s heart and traces the patterns of his or her heartbeat onto paper.
• Chest X-ray exam.
• Echocardiogram. One of two types may be used:
  • Transthoracic echocardiogram (TTE). This test uses sound waves to view images of your child’s heart and blood vessels by placing a wand-like tool on your child’s chest.
  • Transesophageal echocardiogram (TEE). This test uses sound waves to view more detailed images of your child’s heart and blood vessels by passing a flexible tube down the esophagus. The esophagus is the tube in your child’s body that connects the mouth and the stomach.
• MRI or CT scan.
• Cardiac catheterization. In this test:
  • A small, thin tube (catheter) is passed through a large vein in your child’s neck, groin, or arm.
  • Your child’s heart specialist (cardiologist) looks at the heart defect, checks how well the heart is pumping, and checks the function of the heart valves.

How is this treated?

Treatment for this condition depends on the size of the hole and the amount of blood that goes into the right atrium. Small ASDs often cause no symptoms, so they may not require treatment. Larger ASDs may cause symptoms that require medical treatment.

• Treatment may not be needed if your child has a small ASD. In this case, only a small amount of blood is moving back and forth (shunting) from the left to right atrium.
• Depending on the type and location of the defect, ASD closure may be done with a small incision. This treatment is done in a cardiac catheterization lab.
  • A catheter is inserted into a large blood vessel.
  • The catheter is gradually sent through the vessel to the ASD.
  • A patch that looks like a small umbrella is threaded up the catheter and placed in the ASD hole.
  • The patch is then “opened up” to close off the hole.
• Open heart surgery may be necessary if the catheter procedure cannot be done. In open heart surgery:
  • If the ASD is small, the hole can be closed with stitches.
  • If the ASD is large, a patch is sewn over the defect so the hole is closed.

Get help right away if:

• Your child appears unusually tired when playing, taking part in sports, or doing other high-energy activities.
• Your child has chest pain when resting or with activity.
• Your child’s fingertips or lips appear pale or blue.