Diseases & Conditions


Atrial Septal Defects

Synonyms of Atrial Septal Defects
  • ASD
  • Atrioseptal Defects

Disorder Subdivisions

  • Ostium Primum Defect (endocardial cushion defects included)
  • Ostium Secundum Defect
  • Sinus Venosus

General Discussion
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.

Organizations related to Atrial Septal Defects
  • American Heart Association
    National Center
    Dallas TX 75231-4596
    Phone #: 214-373-6300
    800 #: 800-242-8721
    e-mail: [email protected]
    Home page: http://www.americanheart.org
  • American Lung Association
    61 Broadway, 6th Floor
    New York NY 10006
    Phone #: 212-315-8700
    800 #: 800-586-4872
    e-mail: N/A
    Home page: http://www.lungusa.org
  • Congenital Heart Anomalies, Support, Education, & Resources
    2112 North Wilkins Road
    Swanton OH 43558
    Phone #: 419-825-5575
    800 #: --
    e-mail: [email protected]
    Home page: http://www.csun.edu/~hcmth011/chaser/chaser-news.html
  • Congenital Heart Information Network
    1561 Clark Dr
    Yardley PA 19067
    Phone #: 215-493-3068
    800 #: --
    e-mail: [email protected]
    Home page: http://www.tchin.org
  • Kids With Heart National Association for Children's Heart Disorders, Inc.
    1578 Careful Dr
    Green Bay WI 54304-2941
    Phone #: 920-498-0058
    800 #: 800-538-5390
    e-mail: [email protected]
    Home page: http://www.kidswithheart.org
  • Little Hearts, Inc.
    P.O. Box 171
    Cromwell CT 06416
    Phone #: 860-635-0006
    800 #: 866-435-4673
    e-mail: [email protected]
    Home page: http://www.littlehearts.org
  • MUMS (Mothers United for Moral Support, Inc) National Parent-to-Parent Network
    150 Custer Court
    Green Bay WI 54301-1243
    Phone #: 920-336-5333
    800 #: 877-336-5333
    e-mail: [email protected]
    Home page: http://www.netnet.net/mums/
  • Madisons Foundation
    PO Box 241956
    Los Angeles CA 90024
    Phone #: 310-264-0826
    800 #: N/A
    e-mail: [email protected]
    Home page: http://www.madisonsfoundation.org
  • March of Dimes Birth Defects Foundation
    1275 Mamaroneck Avenue
    White Plains NY 10605
    Phone #: 914-428-7100
    800 #: 888-663-4637
    e-mail: [email protected]
    Home page: http://www.marchofdimes.com
  • NIH/National Heart, Lung and Blood Institute Information Center
    P.O. Box 30105
    Bethesda MD 20824-0105
    Phone #: 301-592-8573
    800 #: --
    e-mail: [email protected]
    Home page: N/A

For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders, Inc. ? (NORD). A copy of the complete report can be obtained for a small fee by visiting the NORD website. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational treatments (if available), and references from medical literature. For a full-text version of this topic, see http://www.rarediseases.org/search/rdblist.html