Definition An atrial septal defect is an abnormal opening in the wall of the heart that separates the right from the left atrium.
What is going on in the body? The heart has 4 chambers. Two of the chambers are called atria. There is the right atrium and the left atrium. A defect or hole in the wall, or septum, causes blood to flow abnormally between these 2 chambers. The defect is generally present at birth.
What are the signs and symptoms of the condition? Symptoms depend on how large and where in the wall the defect is. People with small defects may not have any symptoms. Symptoms can occur during infancy and childhood if there is a large defect. Many times symptoms do not appear until adolescence or adulthood. The wall defect may cause:
difficulty breathing and shortness of breath, often made worse by activity
abnormal heart sounds or "murmurs" that a doctor can hear with a stethoscope
weakening or failure of the heart
What are the causes and risks of the condition? The exact cause of this condition is often unknown. The heart develops abnormally before the person is born. Certain infections while a person is in the womb and inherited conditions can increase the risk of this condition. For example, Down syndrome increases the risk. Alcohol abuse by pregnant women may cause some cases.
The risks of this condition often depend on the size and location of the defect. Breathing problems and weakening or failure of the heart can occur with more severe defects. Irregular heartbeats may occur in affected people. This condition may cause an increased risk of certain lung and heart infections in some cases. Other heart defects are also present in certain cases, making treatment more complex.
What can be done to prevent the condition? Most cases of this condition are not preventable. Alcohol should not be used during pregnancy. Women who may get pregnant should make sure all their vaccines are up to date, which may help prevent some cases.
How is the condition diagnosed? The history and physical examination may lead a doctor to suspect this condition. An ECG or heart tracing may show certain abnormalities. A chest x-ray may show enlargement of the heart or certain blood vessels. An echocardiogram, or ultrasound of the heart and its blood flow, is used to diagnose this defect. A special x-ray test called a cardiac catheterisation may be used to confirm the diagnosis.
What are the long-term effects of the condition? Long-term effects depend on the size and location of the wall defect. Larger defects may cause trouble breathing and heart weakening or failure.
What are the risks to others? There are no risks to others
What are the treatments for the condition? People with small defects may not need treatment. People with large defects usually need surgery. This helps prevent further heart and lung problems. Surgery is generally very effective in closing the defect and is quite safe. People who already have heart and lung problems from their wall defect may need medical treatment before they can have surgery. An ASD closure device can also be used. This is a metallic instrument inserted under local anaesthetic from the right groin artery
What are the side effects of the treatments? All surgery carries a risk of bleeding, infection and reaction to the anaesthetic. Rarely, irregular heartbeats or death occur because of the surgery. Medications used for heart failure or irregular heartbeats may cause side effects. These include allergic reactions, salt imbalances, and other side effects. Other side effects depend on the medication used.
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? Repeat doctor visits are needed to make sure the heart has healed and is working properly.
Author: Eric Berlin, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
