If you recollect the anatomy of the heart, you will see that the left and the right side of the heart are separated by muscle tissue. This muscle tissue is called the ‘septum’.
The muscle tissue that separates the left and the right atrium is called the atrial septum. A hole in this septum is called an atrial septal defect. Here we shall take a look at this condition in a little more detail.
What is an atrial septal defect?
An atrial septal defect is a hole in the septum that separates the left and right atrium. It is sometimes referred to as an ASD.
ASD is present from birth, meaning it is a birth defect. Most small ASDs may close during childhood, while a small proportion will remain open till adulthood.
Large atrial septal defects can cause problems.
Causes of atrial septal defect
Many a times, there is no clear cause that is found. Atrial septal defects are birth defects, and there may be some role for genetics.
There are certain risk factors though. Atrial septal defects can be seen in children with Down syndrome. Mothers who are affected by Rubella infection during pregnancy may have children with ASD. Using drugs and alcohol during pregnancy can also increase the risk.
What happens in atrial septal defect?
If you look at the circulation of blood through the heart, there is no connection between the left and the right heart through the septum.
However, in an ASD, the blood that is rich in oxygen (on the left side of the heart) flows across the hole into the right side of the heart that has blood poor in oxygen.
This means that more blood will start to flow to the lungs (the lungs are directly connected to the right heart). Over time, the right heart can become bigger due to the increasing amount of blood entering it. The pressure in the lungs can also increase, leading to pulmonary hypertension (high blood pressure in the lungs).
What are the symptoms of ASD?
A large number of children with ASD do not have any symptoms till they are grown adults. Patients may start to notice symptoms only in their 30’s.
The common symptoms include –
- Breathing difficulty – This is particularly worse when exercising
- The presence of a murmur on examination of the patient – This is an extra sound that the doctor will hear when he/she places the stethoscope on the chest.
- Palpitations or missed heart beats
- Swelling of the legs
- Constant infections in the chest
- Blue fingers and toes (seen in advanced cases)
If you or your child have any of these symptoms or signs, it is strongly recommended that you see your doctor.
Diagnosis of an atrial septal defect
The best way to diagnose an ASD is through echocardiography. The images can clearly show a hole in the heart, and can also estimate how much stress the heart is under.
Patients with an ASD may need additional tests such as –
- Chest xray
- Coronary angiogram
- Magnetic resonance imaging (MRI scan)
On every visit to your doctor, a detailed clinical examination will be conducted. Oxygen levels will be measured using a pulse oximeter. This can help determine how much oxygen rich blood is circulating in the body.
Treatment of atrial septal defect
Most patients who have an ASD will not require treatment in childhood. This is because the defect tends to close by itself.
If the defect does not close, certain treatments will be offered to the patient.
1. Medical treatment
Medical treatment does not close the defect. It can however help keep the heart rate regular, and can reduce the chances of formation of blood clots within the heart.
Medication that may be prescribed include beta blockers and digoxin. Blood thinners such as Acetrom, Aspirin or Warfarin may be prescribed.
2. Surgical treatment
There has been a lot of research that has been conduced in atrial septal defect management. Closing the hole can be achieved through insertion of a small device called an Amplatzer device or through open heart surgery. The hole can also be closed by a patch of tissue.
The Amplatzer device is a small mesh that sits on either side of the hole, closing it completely.
Th decision whether or not to close an ASD depends on the patient’s symptoms and the corresponding findings on an echocardiogram.
What you can and cannot do
Firstly, follow the advice your doctor gives you. Advice is different for different patients, and the information below may not apply to everyone.
1. Eat a healthy diet rich in fruits and vegetables. Keep the fat content of the food low.
2. Exercise regularly. The presence of an ASD should not stop you from enjoying activities that you are passionate about. Please do consult your doctor first.
There is not much one can do to prevent their child from developing an ASD. If an ASD is detected, make sure you follow the advice of your cardiologist.
Information for parents of children with ASD
If your child has been born with an atrial septal defect, the following points might be useful –
1. Most children do not have any symptoms or any problems with a small ASD. No surgery or intervention is needed.
2. Large ASDs may cause symptoms as described above, and you should make sure you see a pediatric cardiologist as soon as possible.
3. Small atrial septal defects do not require treatment. Simple observation is sufficient. Keep your appointments with your doctor.
4. Large defects can cause breathing problems, and it is a good idea to get them closed. Closing them can prevent long term problems in the future. Procedures are safe and have good long term outcomes. Patients can have a good quality of life after. Once again, go by what your pediatric cardiologist is advising you.
5. Your child will have a good quality of life after the defect is closed. During the time that they have an open defect, the doctor may advise certain activity restrictions. Once the hole is closed, children can resume normal activity after a short period of recovery.
Once surgery is done, children will not need any medication. They may require annual follow up with the cardiologist.