How the heart works
The heart is divided into four hollow chambers, two on the right and two on the left. In performing its basic job — pumping blood throughout the body — the heart uses its left and right sides for different tasks.
The right side of the heart moves blood to the lungs through vessels called pulmonary arteries. In the lungs, blood picks up oxygen and then returns to the heart's left side through the pulmonary veins. The left side of the heart then pumps the blood through the aorta and out to the rest of the body.
How heart defects develop
Most heart defects develop when a baby is still in the womb. During the first month of gestation, the fetal heart begins beating. At this point, the heart is just a vaguely heart-shaped tube. Soon the structures that will form into the heart's two sides and the large blood vessels that carry blood in and out of them develop.
It's usually at this point in a baby's development that heart defects may begin to develop. Researchers aren't sure exactly what causes defects to begin, but they think some medical conditions, medications and genetics may play a role.
Why congenital heart disease resurfaces in adulthood
Some adults may find that problems with their heart defects arise later in life, even if their defects were treated in childhood. This is because heart defects are seldom cured — they are often repaired, so your heart function is improved, but it's often not completely normal.
There are many reasons why heart defects re-emerge in adults. In some cases, the treatment you received in childhood may have been successful then, but the problem worsens later in life. It's also possible that problems in your heart, which weren't serious enough to repair when you were a child, have worsened and now require treatment.
There are other complications of childhood surgeries to correct congenital heart disease that can occur later in life. Many treatments to repair heart defects may leave scar tissue behind in your heart that causes an increased chance of abnormal heart rhythm (arrhythmia).
May 08, 2014
- Bonow RO, et al. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, Pa.: Saunders Elsevier; 2012. http://www.clinicalkey.com. Accessed Dec. 20, 2013.
- Kempny A, et al. Meeting the challenge: The evolving global landscape of adult congenital heart disease. International Journal of Cardiology. 2013;168:5182.
- Zomer AC, et al. Adult congenital heart disease: New challenges. International Journal of Cardiology. 2013;168:105.
- What are congenital heart defects? National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/health-topics/topics/chd/. Accessed Dec. 20, 2013.
- Before pregnancy. American Diabetes Association. http://www.diabetes.org/living-with-diabetes/women/pregnant-women/before-pregnancy.html. Accessed Dec. 20, 2013.
- Overview of congenital cardiovascular anomalies. The Merck Manuals: The Merck Manual for Health Care Professionals. http://www.merckmanuals.com/professional/pediatrics/congenital_cardiovascular_anomalies/overview_of_congenital_cardiovascular_anomalies.html. Accessed Dec. 22, 2013.
- Lifestyle changes for heart failure. American Heart Association. http://www.heart.org/HEARTORG/Conditions/HeartFailure/PreventionTreatmentofHeartFailure/Lifestyle-Changes-for-Heart-Failure_UCM_306341_Article.jsp. Accessed Dec. 26, 2013.
- Goldman L, et al. Goldman's Cecil Medicine. 24th ed. Philadelphia, Pa.: Saunders Elsevier; 2012. http://www.clinicalkey.com. Accessed Dec. 20, 2013.
- Riggin EA. Decision Support System. Mayo Clinic, Rochester, Minn. Jan. 9, 2014.