An atrial septal defect (ASD) is a hole in the septum, which is the muscular wall that separates the heart’s two upper chambers. An ASD is a congenital heart defect that happens when the septum does not form properly.

If an ASD is larger than 2cm, patients have a greater risk of problems such as:

• Right heart enlargement, which leads to heart failure
• Abnormal heart rhythms, including atrial fibrillation or atrial flutter
• Stroke
• Pulmonary hypertension
• Leaking tricuspid and mitral valves caused by an enlarged heart

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Signs & Symptoms

Many people have no idea they have an ASD because they do not have symptoms. Some patients find out about the defect when a chest X-ray for another problem shows that the right side of the heart is bigger than normal.

By age 50, an ASD can cause symptoms like:

• Shortness of breath
• Fainting
• Irregular heart rhythms
• Fatigue after mild activity or exercise

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Diagnosis

Tests to check for an ASD include:

• Electrocardiogram (ECG/EKG)
• Transthoracic echocardiography
• Transesophageal echocardiography (TEE)
• Intracardiac echocardiography (ICE)
• Right heart catheterization
• Left heart catheterization