How Serious Is Atrial Septal Defect (ASD)?

The heart is divided into four chambers. The right two chambers move blood to the lungs where it picks up oxygen and moves it to the left two chambers of the heart. From here, the oxygen-rich blood is transported to all the parts of the body via the aorta. 

As a fetus' heart develops during pregnancy, there are usually several openings in the wall dividing the upper chambers of the heart atria. These typically close during pregnancy or soon after birth. However, if one of these openings does not close, a hole is left, and atrial septal defect ASD occurs. As a result, the opening increases the amount of blood that flows through the lungs and may gradually cause damage to the blood vessels in the lungs.

There is no specific cause for ASD. Most congenital heart defects are caused by a combination of genetic factors and certain conditions in the mother while she is pregnant, for example:

• Alcohol consumption
• Recreational drug use
• Illnesses such as diabetes or lupus
• Infections (TORCH complex, or toxoplasmosis, rubella, cytomegalovirus, herpes)

1. Secundum: Occurs in the wall between the atria (atrial septum).
2. Primum: Occurs in the lower part of the atrial septum and occurs along with other congenital heart problems.
3. Sinus venosus: Occurs in the upper atrial septum and is associated with other congenital heart problems.
4. Coronary sinus: Most severe and rare type of ASD in which a part of the wall between the coronary sinus and the left atrium is missing.

Children with ASD experience no obvious symptoms and appear to be healthy, especially if the hole in the heart is small. If the ASD is large, the child may show symptoms such as:

• Easily fatigued
• Fast breathing
• Slow development
• Respiratory diseases 
• Heart arrhythmias

Older children and adults with ASD may experience severe migraines and tiny blood clots in the circulation system that can lead to a stroke.

In order to diagnose ASD, the doctor will first check for abnormal heart murmurs with a stethoscope and then order a few tests:

• Chest X-ray: May show a defect in the heart or changes in the child’s lungs due to the blood changes caused by ASD.
• Electrocardiogram (ECG): Records the electrical activity of the heart and shows arrhythmias that may be caused by ASD.
• Echocardiogram: Uses sound waves to make a moving image of the heart and heart valves. The test can show how the blood flows through the atrial septal opening and reveal how big the hole is.
• Cardiovascular catheterization: Contrast dye is used during heart catheterization to obtain a clearer picture of the heart.

Atrial septal defect typically closes on its own during early childhood. However, ASD that does not resolve and are large may require treatment:

• Clinical monitoring: Observation may be recommended to check to see whether it closes on its own.
• Medication: While medications will not heal or repair the hole, it may help reduce symptoms. Prescribed medications may include beta-blockers to keep the heartbeat normal or anticoagulants to decrease the risk of blood clots.
• Surgery: Many doctors recommend surgery for medium to large-sized ASD to prevent future complications.
  • Cardiovascular catheterization: A catheter is inserted into a vein in the groin and guided to the heart. Through the catheter, a cross-section patch or plug is placed close to the opening. Heart tissue grows around the cross-section, fixing the opening.
  • Open-heart surgery: This type of surgery is done under sedation and requires the use of a heart-lung machine. Through an incision in the chest, patches are used to close the opening. This is the best way to fix primum, sinus venosus, and coronary sinus atrial defects.