About our e-newsletters
- Free e-newsletters
- Mayo Clinic expertise
- We do not share your e-mail address
Housecall, our weekly general-interest e-newsletter, keeps you up to date on a wide variety of health topics with timely, reliable, practical information, recipes, blogs, questions and answers with Mayo Clinic experts and more. Our biweekly topic-specific e-newsletters also include blogs, questions and answers with Mayo Clinic experts, and other useful information that will help you manage your health.
Housecall Archives
Mayo Clinic Housecall
Stay up to date on the latest health information.
What you get
- Free weekly e-newsletter
- Mayo Clinic expertise
- Recipes, tools and other helpful information
- We do not share your e-mail address
Causes
By Mayo Clinic staff
Transposition of the great arteries occurs during fetal growth when your baby's heart is developing. Why this defect occurs is unknown in most cases.
Normally, the pulmonary artery — which carries blood from your heart to your lungs to receive oxygen — is attached to the lower right chamber (right ventricle). From your lungs, the oxygen-rich blood goes to your heart's upper left chamber (left atrium), through the mitral valve into the lower left chamber (left ventricle). The aorta is normally attached to the left ventricle. It carries oxygen-rich blood out of your heart back to the rest of your body.
In transposition of the great arteries, the positions of the pulmonary artery and the aorta are switched. The pulmonary artery is connected to the left ventricle, and the aorta is connected to the right ventricle. Oxygen-poor blood circulates through the right side of the heart and back to the body without passing through the lungs. Oxygen-rich blood circulates through the left side of the heart and right back into the lungs without being circulated to the rest of the body.
Circulation of oxygen-poor blood through the body causes the skin to have a blue tint (cyanosis). Because of this, transposition of the great arteries is called a congenital cyanotic heart defect.
Although some factors, such as rubella or other viral illnesses during pregnancy, maternal age over 40, or maternal diabetes, may increase the risk of this condition, in most cases the cause is unknown.
- Transposition of the great arteries. Centers for Disease Control and Prevention. http://www.cdc.gov/ncbddd/birthdefects/TranspositionGreatArteries.htm. Accessed Feb. 9, 2010.
- d-Transposition of the great arteries. American Heart Association. http://www.americanheart.org/presenter.jhtml?identifier=11074. Accessed Feb. 9, 2010.
- Transposition of the great arteries. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merck.com/mmpe/print/sec19/ch287/ch287h.html. Accessed Feb. 9, 2010.
- Congenital heart defects. The March of Dimes. http://www.marchofdimes.com/professionals/14332_1212.asp. Accessed Feb. 9, 2010.
- Aboulhosn JA, et al. Congenital heart disease in adults. In: Fuster V, et al. Hurst's The Heart. 12th ed. New York, N.Y.: McGraw-Hill Medical; 2008. http://www.accessmedicine.com/content.aspx?aID=3073065. Accessed Feb. 11, 2010.
- Grogan M (expert opinion). Mayo Clinic, Rochester, Minn. Feb. 16, 2010.
Find Mayo Clinic on