Atrial Septal Defects
Atrial septal defect (ASD), is a congenital defect of the heart, or one present at birth. It is an abnormal opening in the wall that separates the two upper chambers of the heart.
What is going on in the body?
The heart has four chambers. The two upper chambers are called the atria. An ASD is a defect or hole in the wall between these chambers. The hole allows blood to flow abnormally between the chambers. ASD is a relatively common cause of congenital heart disease.
What are the causes and risks of the condition?
The exact cause of ASD is often unknown. The heart develops abnormally before the person is born. Some factors that increase the risk of ASD are:
- alcohol ingested by the mother during her pregnancy
- chromosomal abnormalities, such as Down syndrome or Turner''s syndrome
- an infection, such as rubella, within the womb
- medicines and drugs, such as retinoic acid, taken by the mother during pregnancy
What can be done to prevent the condition?
An atrial septal defect is often not preventable. Pregnant women should avoid alcohol. A woman who may get pregnant should make sure all her vaccines are up to date, to lower her risk of contracting an infection that can be passed on to her unborn child.
How is the condition diagnosed?
Diagnosis of ASD begins with a medical history and physical exam. An ECG (heart tracing), may show certain abnormalities. A chest X-ray may show enlargement of the heart or certain blood vessels. Often, an echocardiogram, or ultrasound of the heart, is used to diagnose the defect. A special X-ray test called a cardiac catheterization is generally used to confirm the diagnosis.
Long Term Effects
What are the long-term effects of the condition?
The effects of an ASD depend on the size and location of the defect. Breathing problems and congestive heart failure can occur with serious unrepaired defects. An ASD may also cause arrhythmias and infections of the heart or lungs. The ASD may occur together with other congenital heart defects, such as ventricular septal defect. This combination is more serious than ASD alone.
What are the risks to others?
An ASD is not contagious and poses no risk to others.
What are the treatments for the condition?
If the ASD is small, the person may not need treatment. Congestive heart failure and arrhythmias may be treated with medicines.
Large defects must usually be repaired using open heart surgery. This helps prevent further heart and lung problems. As open heart procedures go, ASD repair is simple, effective, and quite safe.
People with heart and lung problems from their defect may need medical treatment before they can have surgery.
Sometimes ASD's can be repaired using a device delivered on a catheter.
What are the side effects of the treatments?
Surgery carries a risk of bleeding, infection, and allergic reaction to the anesthetic. Rarely, arrhythmias or death occur because of the surgery. Medicines used for congestive heart failure or arrhythmias may cause allergic reactions or salt imbalances.
What happens after treatment for the condition?
In uncomplicated cases, people can usually return to normal activity after recovery. Some people may require further treatment if heart or lung damage was severe before surgery.
How is the condition monitored?
In some cases, the individual may need regular visits to the healthcare provider. Periodic ECGs and echocardiograms may be ordered. Any new or worsening symptoms should be reported to the healthcare provider.
Merck Manual 1999
Current Medical Diagnosis and Treatment, 1996
Harrisons Principles of Internal Medicine, 1991