Overview
An Atrial Septal Defect (ASD) is a congenital (present at birth) heart defect. In this condition, there is a hole in the septum (wall) that divides the atria (two upper chambers) of the heart. This hole leads to an increased blood flow to the lungs. The hole varies in size, may require surgery or may very rarely close on its own.
Associated Anatomy of ASD
Heart and lungs
Alternate Name of Atrial Septal Defect
ASD, hole in the heart
Atrial Septal Defect Causes
The exact cause of atrial septal defect remains unknown. This structure problem occurs during the development of the heart while the baby is still in the mother’s womb. However, a few factors that can cause this defect are:
- Genetic defects
- Use of certain medications
- Certain medical conditions
- Smoking and drinking habits
- Diseases such as rubella, lupus, and diabetes
- Environmental or lifestyle factors.
Atrial Septal Defect Symptoms
Not all babies born with atrial septal defects show any signs or symptoms. Many symptoms may be gauged only in adulthood. Some patients get to know about their condition when a doctor sees them and an OT chest X-ray is taken for another problem and the report shows a bigger size of the right side of the heart. Some of the common signs and symptoms of atrial septal defect include:
- Shortness of breath (especially when indulging in physical activities like exercising)
- Frequent fainting episodes
- Fatigue
- Arrhythmias (irregular heartbeats)
- Irregular heart rhythms (sensation of a rapid heartbeat or skipped beats)
- Heart murmur (the whooshing sound heard through a stethoscope).
Atrial Septal Defect Diagnosis
Tests carried out to diagnose ASD include:
Echocardiogram
An echocardiogram depicts the movement of blood through the heart valves and the heart. The test uses sound waves to picture the heart in motion. It shows the hole, the condition of chambers, heart function and shunt calculation across while and most importantly. The adequacy of making for device closure. Sometimes TEE is required to answer these questions.
Chest X-ray
This X-ray displays the condition of the lungs and heart.
Electrocardiogram (ECG ) & RSR Pattern
Carried out to test the heart’s electrical activity, an ECG is a quick and painless method to identify arrhythmias.
Cardiac magnetic resonance imaging scan (MRI scan)
This scan is carried out when echocardiography fails to provide a decisive diagnosis. With the help of an imaging test that uses radio waves and magnetic fields, cardiac MRI gives detailed images of the heart.
Computed tomography (CT) scan
CT scans are used to diagnose congenital heart defects including the atrial septal defect. The scan creates thorough images of the heart by using a series of X-rays.
Atrial Septal Defect Treatment
The treatment for atrial septal defect is determined by several factors such as the size of the hole, and whether your child or you suffer from any other congenital heart conditions. Your options for the treatments are:
Surgery or other procedures
To prevent future complications, cardiologists recommend surgical processes to repair an atrial septal defect that is medium to large. The procedure can be done two ways (for both children and adults):
Catheter-based repair
A catheter (thin, flexible tube) is put into a blood vessel (usually in the groin) and directed towards the heart with the help of imaging techniques. A Device patch is sent via the catheter that closes the hole. The hole is further closed down permanently with the growth of heart tissue around the seal.
Open-heart surgery
Open heart Surgery is required for very large holes or with associated conditions or where a device is not possible due to incomplete margins or for device failure or migration. This surgery requires direct access to the heart and is done by making an incision through the chest walls. The hole is closed by applying patches directly to it. Surgery is nowadays possible through small incisions and use of robots in selected cases.
Risk Factors of Atrial Septal Defect
Certain conditions increase the risk of the development of atrial septal defect among babies. These things include:
- Rubella infection during early months of pregnancy
- Alcohol or tobacco use
- Diabetes
- Lupus
- Illegal drug use (for instance cocaine)
- Use of anti-seizure medications
- Drugs to treat mood disorders.
Complications of Atrial Septal Defect
Small atrial septal defects might not create any concern and close during infancy. But the larger atrial septal defects can pose serious threats like stroke, right-sided heart failure, arrhythmia early death, and pulmonary hypertension, which can cause permanent lung damage.
Atrial Septal Defect Prevention
As the cause of atrial septal defect remains unknown, preventing it is not possible. You can, however, get good prenatal care. If you are suffering from an atrial septal defect and are planning to have a baby, talk to your doctor about:
Your medications and health conditions
Your doctor will analyze certain health conditions, such as lupus or diabetes, during pregnancy. He/she might also stop or adjust certain medications before you conceive.
Studying family medical history
A genetic counselor can determine your risks if your family has a history of genetic conditions or congenital heart defects.
Immunity test for rubella (German measles)
Rubella in expecting mothers has been linked to various congenital heart defects in the baby. Your doctor can recommend vaccination for the same.
Epidemiology of Atrial Septal Defect
- Atrial septal defect is a common and frequent type of congenital heart disease among children.
- The disease has an incidence rate of 56 per 100,000 live births in the world and is prevalent in 1.6 per 1000 live births.
Expected Prognosis of Atrial Septal Defect
A repaired atrial septal defect in childhood shows better results and has an excellent prognosis with a survival rate close to the general population. Moreover, when atrial septal defects are repaired after the age of 40 years, it improves prognosis, with a reduction in mortality and morbidity with little improvement in exercise capacity.
Natural Progression of Atrial Septal Defect
People who do not undergo surgery to close large atrial septal defects have worse long-term effects. They have reduced functional capacity (difficulty in performing daily chores) and are at greater risk of pulmonary hypertension and arrhythmias.
Pathophysiology of Atrial Septal Defect
Atrial septal defects permit communication between the pulmonary and systemic circulations. The size of the defect and relative atrial pressure between the left and right ventricles impact the nature of the shunt and also influences the magnitude of blood flow. Thus, the intracardiac pressures or hemodynamic condition controlling the ventricular compliances impacts the interatrial shunt. In case the interatrial shunt is significant and longstanding, it would lead to an overload on the chronic right-sided cavities and can pose a serious threat to survival and morbidity.