What is ASD?
An atrial septal defect (ASD) is a hole in the wall separating the two upper chambers of the heart (atria). Normally, this wall completely divides the right and left atria. When a defect is present, oxygenated blood from the left atrium flows into the right, placing extra strain on the lungs.
ASD accounts for 6–10% of all congenital heart defects. It occurs twice as often in girls as in boys. In many cases it goes unnoticed for years — children appear healthy well into school age.
"One of the insidious things about ASD is that children have no complaints for years. Then at 30 or 40 they show up with pulmonary hypertension. Early detection literally changes the entire trajectory."
Symptoms in Children
Small ASDs often produce no symptoms at all. With moderate or large defects the following may be observed:
- Frequent bronchitis, pneumonia, and pulmonary infections
- Shortness of breath during physical activity
- Easy fatigue and reduced activity levels
- Delayed growth and weight gain
- Heart murmur (detected by a paediatrician)
- Arrhythmia (in older patients)
When is Surgery Needed?
Not every ASD requires intervention. Small defects (under 5 mm) often close on their own — especially within the first two years of life. Moderate (6–15 mm) and large (over 15 mm) defects, however, require treatment.
Important: Leaving an ASD untreated in the hope it will "go away on its own" can have serious consequences. A large defect leads to pulmonary hypertension, right-sided heart enlargement, and arrhythmia. After age 40, closing the defect may no longer be effective.
How is Surgery Performed?
1. Catheter-based (endovascular) closure
A catheter is introduced through a vessel in the groin. A special occluder device closes the defect from inside. The chest is not opened and there is no surgical incision. This is the most widely used modern approach — hospital stay is 1–2 days.
2. Open-heart surgery
Open-heart surgery with cardiopulmonary bypass. The defect is closed with a patch. Used for large or complex defects not amenable to catheter closure.
The choice of method is made individually based on defect size, anatomy, and the child's condition.
Treatment Outcomes
An ASD treated in time means complete recovery. The child leads a normal life, can participate in sports, and is fit for military service. The success rate of elective catheter closure is 97–99%.
Can ASD be seen on echocardiography?
Yes — echocardiography (echo) is the primary diagnostic method for ASD. Colour-Doppler echo accurately shows defect size, direction of blood flow, and the degree of pulmonary loading.
How long does a child stay in hospital after catheter closure?
Typically 2–3 days. One day of observation to confirm device position, then discharge home. Antithrombotic medication is taken for 3–6 months afterwards.
Can a child with ASD play sport?
Children with a small ASD can generally be fully active without restriction. With moderate or large defects, intense exercise is not recommended until the defect is treated. After treatment the child returns to full activity.
Is ASD hereditary?
There is a genetic predisposition — the risk is somewhat higher in a child whose parent has ASD. However, it is not inevitable. Foetal echocardiographic screening is recommended during pregnancy.