Atrial septal defect (ASDs) is a type of congenital heart disease where there is a hole in the wall that separates the two upper chambers (atria) of the heart, called the atrial septum.

The hole present allows oxygenated blood from the left atrium to mix with deoxygenated blood from the right atrium, leading to a reduction in the amount of oxygenated blood that reaches the rest of the body. The consequence is an increased workload on the right side of the heart and eventually, a heart failure.

Atrial septal defect (ASD) is a type of congenital heart defect that affects a large number of people worldwide. Small ASDs usually don’t need treatment. Larger ones may require percutaneous (nonsurgical) repair or surgery to lower the risk of serious complications.

What are the causes of atrial septal Defects?
This results in blood flowing from one atrium to the other, leading to an increased volume of blood in the right atrium and lungs.

Causes of atrial septal defects are generally divided into two categories: genetic and environmental.

Genetic causes include:

Chromosomal abnormalities such as Down syndrome, Turner syndrome, and Patau syndrome.
Inherited genetic conditions such as Marfan syndrome, Loeys-Dietz syndrome, and Ehlers-Danlos syndrome.
Mutations in specific genes such as TBX5 and GATA4
Environmental causes include:

Exposure to certain medications or chemicals during pregnancy, such as alcohol, tobacco, and certain prescription drugs.
Maternal illnesses such as rubella, lupus, and diabetes.
Low birth weight or premature birth

What are the symptoms of an Atrial Septal Defect?
Usually, babies born with atrial septal defects (ASDs) do not show signs or symptoms. When signs and symptoms do appear, a heart murmur is a very common one. Other symptoms include;

Fatigue (tiredness)
Easily getting tired during physical activity
Shortness of breath
A collection of blood and fluid in the lungs
The presence of accumulated fluid in the feet, ankles, and legs

How are atrial septal defects diagnosed?
A physical examination is done to check the heart’s structure and function. Additionally, some series of tests are conducted. These tests to diagnose atrial septal defects include:

Electrocardiography (ECG/EKG): An ECG shows your heart’s electrical activity. It can reveal if you have an arrhythmia or other problems related to your heart’s electrical system.

Chest X-ray: This test will show if your right atrium and right ventricle are enlarged. It’ll also show if the blood vessels in your lungs are affected.

Transthoracic echocardiography (TTE): This test shows how the left-to-right shunting of blood (caused by ASD) affects your heart. It can also show details related to pulmonary hypertension.

Transesophageal echocardiography (TEE): A TEE is an ultrasound taken through your oesophagus. It shows the size, shape and location of an ASD. It can also check your heart valves. TEE is often used during ASD surgery and percutaneous repair.

Intracardiac echocardiography (ICE): This is an ultrasound taken inside your heart. A tiny camera (echo probe) is sent to your heart through a peripheral vein. This test shows the size and shape of the ASD and the direction of the blood flow across it. It’s often used during percutaneous (nonsurgical) repair of ASD.

How is Atrial Septal Defect treated?
Regular checkups are performed to see if an Atrial Septal Defect (ASD) closes on its own. About half of all ASDs close on their own with time, and about 20 percent close within the first year of life.

There are several treatment options for ASDs, depending on the size and severity of the defect, as well as the patient's overall health and age.

Watchful waiting: For smaller ASDs that cause no symptoms or only mild symptoms, a wait-and-see approach may be appropriate. In these cases, regular check-ups with a cardiologist can monitor the defect and ensure it is not getting worse.
Medications: In some cases, medications may be prescribed to manage symptoms such as fatigue, shortness of breath, or rapid heartbeat.
Catheter-based closure: This is a minimally invasive procedure that uses a catheter to close the defect. A small device is inserted through a vein in the leg and guided to the heart to seal the ASD.
Open-heart surgery: For larger or more complex ASDs, open-heart surgery may be necessary. During this procedure, the surgeon will make an incision in the chest and repair the defect directly.

Open-Heart Surgery in Nigeria
Open-heart surgery generally is performed to repair primum or sinus venosus ASDs. This procedure is performed under general anesthesia and typically takes 2 to 4 hours to complete. During the surgery, a large incision is made in the chest, and the heart is temporarily stopped to allow the surgeon to access the septum and repair the hole.

What happens during open heart surgery

The specific method to repair atrial septal defects during open heart surgery depends on the size and location of the hole. For small defects, the surgeon may simply sew the hole closed. For larger defects, a patch may be used to cover the hole. After the repair is complete, the heart is restarted and the incision is closed.

What is the recovery process after atrial septal defects surgery?
The outlook for children after ASD procedure is excellent. Typically, children spend 3 to 4 days in the hospital before going home. Complications, such as bleeding and infection, from ASD surgery are very uncommon.

Some children may notice inflammation of the outer lining of the heart, a condition called pericarditis (PER-i-kar-DI-tis). This leads to fluid collection around the heart in the weeks after surgery. This complication of heart surgery normally resolves with medicine.

While in the hospital, your child will be given medicines as required to reduce pain or anxiety. The doctors and nurses at the hospital will show you how to care for your child at home.

They will discuss preventing blows to the chest as the incision heals, reducing activity while your child recovers, bathing, scheduling follow-up medical appointments, and deciding when your child can return to his or her normal activities.

Living With atrial septal defects (ASDs)
The outlook for children who have atrial septal defects (ASDs) is excellent. Advances in treatment allow most children who have these heart defects to live normal, active, and productive lives with no decrease in lifespan.

Most children who have these defects need no special care or only periodic checkups with a cardiologist (a heart specialist) as they go through life.

Frequently Asked Questions (FAQs)
How can atrial septal defects be prevented?

Atrial septal defects cannot be prevented as it is a congenital heart condition, meaning it is present at birth and cannot be prevented by any means. However, early detection and proper management can help reduce the risk of complications and improve the quality of life for those with the condition.

Is Atrial Septal Defect a common heart condition in Nigeria?

ASD is one of the most common congenital heart defects worldwide, including in Nigeria. It is often diagnosed in childhood, but some cases may go undetected until adulthood.

Is Atrial Septal Defect treatment always necessary?

The necessity of treatment for ASD depends on the size of the defect and the presence of symptoms. Small Atrial septal defects may close on their own, but moderate to large defects or those causing symptoms often require intervention.

Is Atrial Septal Defect treatment safe in Nigeria?

Atrial septal defect treatment, typically through cardiac catheterization or open-heart surgery, is well-established and considered safe when performed by experienced pediatric or adult cardiac surgeons in Nigeria.

Can adults have Atrial Septal Defects?

Yes, adults can have undiagnosed ASDs that are discovered later in life. These cases are typically managed by adult congenital heart specialists.

What is the prognosis for individuals with ASD?

The prognosis for individuals with ASD is generally good, especially when diagnosed and treated early. Many people with treated ASDs go on to lead healthy lives.