Disease Profile

Ostium secundum atrial septal defect

Prevalence ?
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


Age of Onset





Autosomal dominant ?A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease


Autosomal recessive ?Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype


X-linked dominant ?X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


X-linked recessive ?Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder


Mitochondrial or multigenic ?Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor ?Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other Names (AKA)

ASD ostium secundum type; Ostium secundum ASD; osASD


Congenital and Genetic Diseases; Heart Diseases


An ostium secundum atrial septal defect is a type of congenital heart defect called an atrial septal defect (ASD). An ASD is a hole in the wall (septum) between the two upper chambers of the heart (the atria). ASDs can be classified by location. An ostium secundum ASD is a hole in the center of the atrial septum.[1]

Normally, the right side of the heart pumps oxygen-poor blood to the lungs, while the left side pumps oxygen-rich blood to the body. An ASD allows blood from both sides to mix, causing the heart to work less efficiently.[2]

A small hole may not cause any symptoms or problems. A larger hole can eventually cause symptoms such as shortness of breath, respiratory infections, fainting, irregular heart rhythms or fatigue after mild activity.[2][3] Larger ASDs can also ultimately lead to pulmonary artery hypertension, right ventricular hypertrophy (enlargement); SVT, or heart failure.[1]

Most cases of ASD are not inherited and occur by chance. Some cases appear to have autosomal dominant inheritance.[4]

Treatment may not be needed for small ASDs, which often close on their own.[1] Larger ASDs are typically closed during childhood with open heart surgery or by cardiac catheterization.[3]


This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Left-to-right shunt
30%-79% of people have these symptoms
Exercise intolerance
Decreased ability to exercise
Inability to exercise

[ more ]

Exertional dyspnea

[ more ]

Missed heart beat
Skipped heart beat

[ more ]

Right atrial enlargement
Systolic heart murmur
5%-29% of people have these symptoms
Abnormal left ventricular function
Abnormal mitral valve morphology
Atrial fibrillation
Quivering upper heart chambers resulting in irregular heartbeat
Atrial flutter
Breathing dysregulation
Bundle branch block
Congestive heart failure
Cardiac failure
Cardiac failures
Heart failure

[ more ]

First degree atrioventricular block
Mitral regurgitation
Pedal edema
Fluid accumulation in lower limbs
Lower leg swelling

[ more ]

Pulmonary arterial hypertension
Increased blood pressure in blood vessels of lungs
Right ventricular dilatation
ST segment depression
Supraventricular tachycardia
Tricuspid regurgitation
1%-4% of people have these symptoms
Blue discoloration of the skin
Increased pulmonary vascular resistance
Pulmonary obstruction
Obstructive lung disease
Recurrent bacterial infections
Bacterial infections, recurrent
Frequent bacterial infections
Increased susceptibility to bacterial infections
Recurrent major bacterial infections

[ more ]

Right ventricular failure
Fainting spell
Transient ischemic attack
Mini stroke
Percent of people who have these symptoms is not available through HPO
Aortic valve stenosis
Narrowing of aortic valve
Atrial septal dilatation
Autosomal dominant inheritance
Bicuspid aortic valve
Aortic valve has two leaflets rather than three
Persistent left superior vena cava
Second degree atrioventricular block
Secundum atrial septal defect
Subvalvular aortic stenosis
Narrowing of blood vessel below aortic heart valve
Tetralogy of Fallot with pulmonary atresia
Ventricular septal defect
Hole in heart wall separating two lower heart chambers


Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Organizations Providing General Support

      Learn More

      These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

      Where to Start

      • You can obtain information on this topic from the Centers for Disease Control and Prevention (CDC). The CDC is recognized as the lead federal agency for developing and applying disease prevention and control, environmental health, and health promotion and education activities designed to improve the health of the people of the United States.
      • Mayo Clinic has an information page on Ostium secundum atrial septal defect.
      • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
      • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

        In-Depth Information

        • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
        • The Merck Manual for health care professionals provides information on Ostium secundum atrial septal defect.
        • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
        • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
        • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
        • PubMed is a searchable database of medical literature and lists journal articles that discuss Ostium secundum atrial septal defect. Click on the link to view a sample search on this topic.


          1. Jeanne Marie Baffa. Atrial Septal Defect (ASD). Merck Manual. January, 2014; https://www.merckmanuals.com/professional/pediatrics/congenital-cardiovascular-anomalies/atrial-septal-defect-asd.
          2. Atrial Septal Defect. Cleveland Clinic. 2016; https://my.clevelandclinic.org/services/heart/disorders/congenital-heart/atrial-septal-defect-asd.
          3. Atrial Septal Defect (ASD). American Heart Association. March 23, 2013; https://www.heart.org/HEARTORG/Conditions/CongenitalHeartDefects/AboutCongenitalHeartDefects/Atrial-Septal-Defect-ASD_UCM_307021_Article.jsp#.V6NqR_krJD8.
          4. Marla J. F. O'Neill. ATRIAL SEPTAL DEFECT 1; ASD1. OMIM. February 9, 2012; https://www.omim.org/entry/108800.
          5. Heidi M Connolly. Indications for closure and medical management of atrial septal defects in adults. UpToDate. Waltham, MA: UpToDate; July, 2016;