CausesBy Mayo Clinic staff
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 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. In some cases, the blood pressure in your lungs increases as well, leading to pulmonary hypertension.
- What are holes in the heart? National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/health-topics/topics/holes/. Accessed Oct. 26, 2011.
- Facts about atrial septal defect. Centers for Disease Control and Prevention. http://www.cdc.gov/ncbddd/heartdefects/AtrialSeptalDefect.html. Accessed Oct. 26, 2011.
- Cohen S, et al. Atrial septal defect. In: Ferri FF. Ferri's Clinical Advisor 2012: 5 Books in 1. Philadelphia, Pa.: Mosby Elsevier; 2012. http://www.mdconsult.com/books/about.do?about=true&eid=4-u1.0-B978-0-323-05611-3..C2009-0-38601-8--TOP&isbn=978-0-323-05611-3&uniqId=291436269-101. Accessed Oct. 26, 2011.
- Bernstein D. Acyanotic congenital heart disease: The left-to-right shunt lesions. In: Kliegman RM, et al. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa.: Saunders Elsevier; 2011. http://www.mdconsult.com/das/book/body/208746819-6/0/1608/0.html. Accessed Oct. 26, 2011.
- Vick GW, et al. Management and outcome of isolated atrial septal defects in children. http://www.uptodate.com/home/index.html. Accessed Oct. 26, 2011.
- Atrial septal defect. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merckmanuals.com/professional/print/pediatrics/congenital_cardiovascular_anomalies/atrial_septal_defect_asd.html. Accessed Oct. 26, 2011.
- Wiegers SE, et al. Management of atrial septal defects in adults. http://www.uptodate.com/home/index.html. Accessed Oct. 26, 2011.
- Wiegers SE, et al. Pathophysiology and clinical features of atrial septal defects in adults. http://www.uptodate.com/home/index.html. Accessed Oct. 26, 2011.
- Birth defects. March of Dimes. http://www.marchofdimes.com/baby/birthdefects_congenitalheart.html. Accessed Oct. 26, 2011.
- Questions and answers on the 2010 dietary guidelines advisory committee report. U.S. Department of Agriculture. http://www.cnpp.usda.gov/Publications/DietaryGuidelines/2010/DGAC/Report/QandA-DGACReport.pdf. Accessed Oct. 26, 2011.
- Grogan M (expert opinion). Mayo Clinic, Rochester, Minn. Nov. 8, 2011.