How Does An Atrial Septal Defect Affect The Heart? Symptoms, Diagnosis, And Treatment For ASD

An atrial septal defect — ASD for short — is a congenital disease in which a baby is born with a hole in the wall separating the heart's two upper chambers. The severity of an atrial septal defect varies from person to person. Some patients with small defects will never experience symptoms, and their defects will be discovered only found accidently. Small defects may even close on their own early in childhood. On the other hand, patients with large atrial septal defects can experience significant damage to the heart and the lungs, to a point where it can shorten the patient’s life span due to heart failure or high blood pressure. If the defect is large, surgery is likely necessary to be able to repair the damage as well as prevent complications.

What are the symptoms of atrial septal defects?

In many cases, children born with small atrial septal defects don’t present with any symptoms. These patients may not develop symptoms until the age of 30 or even much later. Generally, the symptoms associated with atrial septal defects include:

• Being short of breath, particularly during exercise
• Being fatigued
• Experiencing swelling of legs
• Having heart palpitations
• Suffering a stroke
• Having a heart murmur, which is an abnormal sound your heart makes when its moving blood.

What is the cause of atrial septal defects?

Unfortunately, the cause of atrial septal defects is not entirely clear. Congenital heart defects often develop as a result of random errors that occur early on in fetal development. Scientists believe that both genetics and environmental factors likely play a role in the development of this disease.

How does an atrial septal defect affect the heart?

The heart is separated into four distinct regions, among which two regions have oxygenated blood destined to go to the rest of the body, while the remaining two regions house deoxygenated blood meant to go the lungs to receive oxygen.

An atrial septal defect means the oxygenated and deoxygenated blood get mixed together, and both are taken to the lungs. This leads to excess volumes of blood in the lungs, and causes the right side of the heart to work much harder. When an atrial septal defect is not treated, the right side of the heart becomes large and weak, leading to hypertension.

What are the risk factors for an atrial septal defect?

The risk factors for an atrial septal defect include:

• Genetics, as congenital heart defects are known to run in families and often develop alongside other genetic disorders including Down’s syndrome.
• A maternal rubella infection (German measles) during pregnancy, particularly during the first trimester, can increase the risk a child develops heart defects.
• Use of drugs, alcohol, tobacco or other substances during pregnancy can cause damage to the fetus and increase the risk a heart defect in the fetus.
• Having diabetes or lupus during pregnancy increase your risk of a baby with a heart defect.
• Being obese during pregnancy heightens the odds, too.
• Having phenylketonuria during pregnancy and not following the appropriate meal plan increases the risk of your baby having a heart defect.

What are some complications that can result from atrial septal defects?

Generally, a small atrial septal defect will not cause major problems and the defect tends to close during childhood. However, patients with larger defects can experience a multitude of problems, including:

• Right-sided heart failure
• Arrhythmias, which refer to abnormal heart rhythm
• Higher risk of a stroke
• Shortened life span
• Pulmonary hypertension, in which the large volumes of blood flow to your lungs cause an increase in blood pressure in the blood vessels of your lung.
• Eisenmenger syndrome, permanent lung damage caused by pulmonary hypertension.

Thankfully, modern medicine can help manage these complications.

Diagnosis of atrial septal defects

Your doctor may initially suspect that your child has a heart defect when they hear a murmur in the heart through a stethoscope. If so, the doctor will order one or more of several tests, such as:

• An echocardiogram, in which sound waves are used to produce a moving picture of the heart.
• A chest X-ray to develop an image of the structures in your chest, such as your lungs and heart.
• An electrocardiogram (ECG) to measure the heart’s electrical activity.
• Cardiac catheterization, in which a small tube is inserted into the blood vessels and guided to the hear to create a detailed picture, as well as to determine how well the heart is pumping.
• Magnetic resonance imaging (MRI), which creates a 3-D images of the heart and other organs.
• A computerized tomography (CT) scan, which uses X-rays to make a very detailed image of the heart.

What is the treatment for atrial septal defects?

In most cases, atrial septal defects repair themselves during childhood. However, some atrial septal defects don’t close and will require treatment. There are several ways to go about this.

Medical monitoring

If the child has a small septal defect, the doctor may choose to just monitor the defect as they tend to close themselves over time.

Medications

While medications can’t help close the hole in the heart, they can help manage the symptoms associated with atrial septal defects. Medications include those that can keep a regular heartbeat (such as beta blockers) or decrease the risk of blood clots (anticoagulants).

Surgery

Surgery is generally recommended for people with medium or large atrial septal defects, though it is not recommended for patients with pulmonary hypertension as it can worsen the condition. Surgery will usually involve closing or patching up the abnormal hole.