Doctors know that heart defects present at birth (congenital) arise from errors early in the heart's development, but there's often no clear cause. Genetics and environmental factors may play a role.
An atrial septal defect (ASD) allows freshly oxygenated blood to flow from the left upper chamber of the heart (left atrium) into the right upper chamber of the heart (right atrium). There, it mixes with deoxygenated blood and is pumped to the lungs, even though it's already refreshed with oxygen.
If the atrial septal defect is large, this extra blood volume can overfill the lungs and overwork the heart. If not treated, the right side of the heart eventually enlarges and weakens. If this process continues, the blood pressure in your lungs increases as well, leading to pulmonary hypertension.
Atrial septal defects can be several types, including:
Dec. 11, 2014
- Secundum. This is the most common type of ASD, and occurs in the middle of the wall between the atria (atrial septum).
- Primum. This defect occurs in the lower part of the atrial septum, and may occur with other congenital heart problems.
- Sinus venosus. This rare defect occurs in the upper part of the atrial septum.
- Coronary sinus. In this rare defect, part of the wall between the coronary sinus — which is part of the vein system of the heart — and the left atrium is missing.
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- St. John Sutton MG. Clinical manifestations and diagnosis of atrial septal defects in adults. http://www.uptodate.com/home. Accessed Aug. 27, 2014.
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- Congenital heart defects and CCHD. March of Dimes. http://www.marchofdimes.org/baby/congenital-heart-defects.aspx. Accessed Aug. 27, 2014.
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- Ferri FF. Ferri's Clinical Advisor 2015: 5 Books in 1. Philadelphia, Pa.: Mosby Elsevier; 2015. https://www.clinicalkey.com. Accessed Sept. 18, 2014.
- Connolly HM. Medical management of Eisenmenger syndrome. http://www.uptodate.com/home. Accessed Sept. 19, 2014.
- St. John Sutton MG. Identification and assessment of atrial septal defects in adults. http://www.uptodate.com/home. Accessed Sept. 19, 2014.
- Vick GW, et al. Management and outcome of isolated atrial septal defects in children. http://www.uptodate.com/home. Accessed Aug. 27, 2014.
- The American Heart Association's diet and lifestyle recommendations. American Heart Association. http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HealthyEating/The-American-Heart-Associations-Diet-and-Lifestyle-Recommendations_UCM_305855_Article.jsp. Accessed Sept. 23, 2014.
- Riggin EA. Decision Support System. Mayo Clinic, Rochester, Minn. Accessed July 10, 2014.
- Mankad R (expert opinion). Mayo Clinic, Rochester, Minn. Nov. 10, 2014.
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