Atrial Septal Defect (ASD)
An atrial septal defect (ASD) is a hole in the wall that separates the heart’s upper chambers, known as the atria. This opening allows additional blood to pass from the left side of the heart to the right, increasing the volume entering the lungs. Over time, this extra flow can place added pressure on the right side of the heart. While small ASDs may not have noticeable effects, larger defects can influence how efficiently the heart and lungs work. Identifying an ASD early helps guide appropriate monitoring and treatment.
Why does it happen?
An ASD is a congenital condition, meaning it is present from birth. It occurs when the septum—the wall between the atria—does not fully develop during early heart formation in the womb. The size and position of the defect can vary from person to person, influencing how much extra blood flows through it. Although the exact reason the wall does not close completely is often unknown, ASDs are recognised as one of the more common congenital heart defects. Many are detected during childhood, but some are only identified later in adulthood.
What are the symptoms?
Small ASDs may remain unnoticed for many years and may not cause any symptoms at all. Larger defects, however, can lead to symptoms as the right side of the heart and lungs handle increased blood flow. These symptoms may appear gradually or during exertion and include:
- Shortness of breath
- Fatigue
- Palpitations
- Swelling in the legs
If symptoms develop or worsen, a specialist assessment is recommended to evaluate the impact on the heart.
How is it diagnosed?
A significant ASD can place persistent strain on the right chambers of the heart and the blood vessels leading to the lungs. Over time, this increased workload may enlarge the right side of the heart and potentially contribute to elevated pressure in the lungs.
If left unaddressed, it can also increase the risk of developing abnormal heart rhythms, particularly atrial fibrillation. Recognising and treating a sizeable ASD helps protect long-term heart and lung function and reduces the likelihood of complications later in life.
How is it treated?
Treatment depends on the size of the defect, its location, and how it affects the heart and lungs. Many ASDs can be closed using a small device inserted through a catheter in a leg vein, avoiding the need for open-heart surgery.
This minimally invasive approach is often well-tolerated and allows a quick recovery. Some defects, depending on their shape or position, are better treated with surgical closure. Repairing the defect generally helps restore normal heart function and significantly reduces the risk of long-term complications.
frequently asked questions
Can an ASD close on its own?
Small ASDs may close naturally during infancy or early childhood. Larger defects usually require medical intervention to prevent long-term heart complications.
How is an ASD diagnosed?
ASDs are typically diagnosed using an echocardiogram, which shows the size and position of the hole and how it affects blood flow. Other tests, like an ECG or chest X-ray, may provide additional information.
What are the treatment options for an ASD?
Many ASDs can be closed using a catheter-based device, avoiding surgery. Larger or more complex defects may need surgical repair to restore normal heart function.
Results and Next Steps
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You can contact us to book an appointment, discuss our services, or request further information about your condition or treatment options. We aim to make every step of your journey as straightforward and reassuring as possible.