Atrial Septal Defects
National Organization for Rare Disorders, Inc.
It is possible that the main title of the report Atrial Septal Defects is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.
Atrial septal defects (ASDs) are a group of rare disorders of the heart that are present at birth (congenital) and involve a hole in the wall (septum) that separates the two upper-chambers (atria) of the heart.
Normally the heart has four chambers: two upper chambers known as atria that are separated from each other by a fibrous partition known as the atrial septum and two lower chambers known as ventricles that are separated from each other by the ventricular septum. Valves connect the atria (left and right) to their respective ventricles. A small opening between the two atria (foramen ovale) is present at birth. Shortly after birth, the atrial septum gradually grows and seals this opening. In infants with atrial septal defects, the atrial septum may not close properly or may be malformed during fetal development. In these disorders, the opening (called patent foramen ovale) between the atria persists long after it should be closed, resulting in an increase in the workload on the right side of the heart and excessive blood flow to the lungs.
Initially, the symptoms associated with atrial septal defects may be absent or so mild that they may go unnoticed. Frequently this disorder is not recognized until school age or even adulthood. In adults with undetected atrial septal defects, various respiratory problems and/or heart failure may develop.
Several forms of atrial septal defects are recognized. They are classified according to their location in the septum. The term primum refers to defects that are in the lower part of the septum. The term secundum refers to defects that are located in the middle of the septum, and the term sinus venosus refers to defects in the upper part of the septum.
March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
American Heart Association
7272 Greenville Avenue
Dallas, TX 75231
American Lung Association
1301 Pennsylvania Ave NW
Washington, DC 20004
NIH/National Heart, Lung and Blood Institute
P.O. Box 30105
Bethesda, MD 20892-0105
Kids With Heart ~ National Association for Children's Heart Disorders, Inc.
1578 Careful Dr.
Green Bay, WI 54304
Little Hearts, Inc.
P.O. Box 171
110 Court Street, Suite 3A
Cromwell, CT 06416
Congenital Heart Information Network (C.H.I.N.)
P.O. Box 3397
Margate City, NJ 08402-0397
Genetic and Rare Diseases (GARD) Information Center
PO Box 8126
Gaithersburg, MD 20898-8126
PO Box 241956
Los Angeles, CA 90024
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It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report
This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.
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Last Updated: 3/12/2008
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