Atrial Septal Defect

What is an Atrial Septal Defect?

An atrial septal defect is a hole in the atrial septum. The atrial septum is the wall between the upper two chambers of the heart, the right and left atria. Atrial septal defects are congenital heart defects - heart defects that are present at birth.

Atrial septal defects can happen on their own or they can occur in children born with other congenital heart defects. Studies have shown that girls are twice as likely to have an atrial septal defect as boys. Doctors don't know why this is.

For more information regarding atrial septal defect services in St. Louis or to make an appointment, please call 314.454.5437 or 800.678.5437
or email us.

Types of Atrial Septal Defects

There are four major types of atrial septal defects, each classified by their location in the heart and the development of the defect:

• Secundum atrial septal defects are an opening in the middle part of the atrial septum. These are the most common type of atrial septal defect and they occur when a part of the atrial septum does not close when the heart is developing.
• Primum atrial septal defects occur in the lower part of the atrial septum close to the tricuspid and mitral valves.
• Sinus venosis atrial septal defects occur in the upper part of the atrial septum near the veins that drain into the right atrium, resulting in abnormal drainage of one or more of the pulmonary veins.
• Coronary sinus atrial septal defects occur when there is a defect in the wall between the coronary sinus and the left atrium. This is the rarest type of atrial septal defect and affects the blood flow from the heart’s own vein.

What Causes an Atrial Septal Defect?

The heart forms during the first 8 weeks of pregnancy. It starts as a hollow tube that divides into 4 chambers. These chambers are separated by walls called septa. It is normal for the walls of the heart to have openings as the fetus grows. These openings usually close shortly before or just after birth. If they don't close, the atrial septum will have a hole in it. This is called an atrial septal defect.

Some congenital heart defects have genetic links and are passed down in certain families. Most atrial septal defects, however, occur by chance. Doctors can find no clear reason why atrial septal defects occur.

Symptoms of Atrial Septal Defects

Many children with an atrial septal defect experience no obvious symptoms and seem healthy, especially if the hole in the heart is small. If the atrial septal defect is large, however, your child may experience more noticeable symptoms, such as tiring easily, shortness of breath, fast breathing, slow growth, respiratory infections or heart arrhythmias. Be sure to talk with your child’s healthcare professional if your child is exhibiting any of these symptoms.

Older children and adults with atrial septal defects may experience migraine headaches, but it is unclear if the hole in the heart is the cause. A small blood clot in the blood stream that causes a stroke can also be associated with atrial septal defects in older children and adults. However, it does not currently appear that closing the opening in the heart or taking anticoagulants (blood thinners) decreases the risk of blood clots or stroke.

For more information regarding atrial septal defect services in St. Louis or to make an appointment, please call 314.454.5437 or 800.678.5437 or email us.

How is an Atrial Septal Defect Diagnosed?

Your child's doctor may have heard a heart murmur when listening to your child's heart with a stethoscope. The heart murmur is from the abnormal flow of blood through the heart.

Your child may need to see a pediatric cardiologist for a diagnosis. This is a doctor with special training to treat heart problems in children. The doctor will examine your child and listen to your child's heart and lungs. The doctor will find out where the murmur is best heard and how loud it is. Your child may have some tests, such as:

• Chest X-ray. This test may show an enlarged heart or it may show changes in your child's lungs because of the blood flow changes caused by an atrial septal defect. 
• Electrocardiogram (ECG). This test records the electrical activity of the heart. It shows abnormal rhythms (arrhythmias) that may be caused by an atrial septal defect. It can also find heart muscle stress caused by an atrial septal defect.
• Echocardiogram. This test uses sound waves to make a moving picture of the heart and heart valves. An echo can show the blood flow through the atrial septal opening and find out how big the opening is.
• Cardiac catheterization. This tests uses a thin, flexible tube called a catheter put near the heart. Contrast dye is used during a cardiac catheterization to get even clearer pictures. In some children, this procedure may be used to close the atrial septal defect.

Treatment for Atrial Septal Defects

Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is. Once an atrial septal defect is diagnosed, your child's cardiologist will check to see if the defect is closing on its own. A secundum atrial septal defect, the most common type of atrial septal defect, often closes on its own as your child grows.

Treatment may include:

• Medicine. Many children have no symptoms and don't need medicine. But medicine can help some children's hearts work better. For example, diuretics (water pills) help the kidneys get rid of extra fluid from the body, which may occur when the heart is not functioning properly.
• Surgery. An atrial septal defect will often be corrected with surgery if it has not closed by the time a child starts school or if the hole in the heart is large. The surgery is done under general anesthesia and the hole in the heart is closed with stitches or a special patch. After the surgery, your child’s doctor may prescribe antibiotics to prevent bacterial endocarditis, an infection of the lining of the heart.
• Device closure. During a cardiac catheterization, a special device called a septal occlude is put into the atrial septal defect. The septal occlude device stops blood from flowing through the hole in the heart.

Living with Atrial Septal Defects

All children with an atrial septal defect need to be cared for by a pediatric cardiologist. Most children who have had an atrial septal defect that closed on its own, was surgically repaired or closed using a septal occlude device will live healthy lives. With early diagnosis and repair of an atrial septal defect, children usually do very well and do not require ongoing follow-up care.

If an atrial septal defect is diagnosed later in life or never repaired, children are more likely to have problems, or they may have complications after the hole is closed. Large atrial septal defects may cause lung problems over time if not treated. This is because the extra blood passing through the defect and then into the lungs may harm the vessels in the lungs.

For more information regarding atrial septal defect services in St. Louis or to make an appointment, please call 314.454.5437 or 800.678.5437 or email us.