Atrial Septal Defect

What happens when oxygen-rich and oxygen-poor blood mix?

An atrial septal defect (ASD) is a hole in your heart’s wall separating the two upper chambers (the atria). This is a birth defect that allows oxygen-rich blood from the left atrium to flow into the oxygen-poor blood of the right atrium instead of into the left ventricle as it should. This means that oxygen-rich blood gets pumped back to the lungs, where it has just been, instead of going to the body. And this causes more work for the right side of the heart.

Adults with an undetected ASD may have a shortened lifespan from heart failure or high blood pressure within the lungs.

If an atrial septal defect is small, it may close on its own during infancy or early childhood and never be an issue. If the atrial septal defect is large, the extra blood volume can overfill the lungs and overwork the heart. This is a disease often detected in early adulthood. If not detected and treated, the right side of the heart eventually enlarges and weakens, which can lead to pulmonary hypertension (a type of high blood pressure) or heart failure. In some cases, surgery may be necessary for repairing the hole and preventing complications.

Symptoms may include:
• Fatigue
• Shortness of breath (especially after physical activity)
• Heart murmur or palpitations
• Swelling in the legs, feet, or abdomen region
• Frequent lung infections
• Stroke

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