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Disease Profile

Cor triatriatum

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.


US Estimated

Europe Estimated

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.


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.


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)

Triatrial heart


Cor triatriatum is an extremely rare congenital (present at birth) heart defect. The human heart normally has four chambers, two ventricles and two atria. The two atria are normally separated from each other by a partition called the atrial septum and the two ventricles by the ventricle septum. In cor triatriatum there is a small extra chamber above the left atrium (cor triatriatum sinistrum) or right atrium (cor triatriatum dextrum). The presence of this extra atrial chamber can cause slowed passage of the blood from the lungs to the heart and, over time, lead to features of congestive heart failure and obstruction.[1][2] In children, cor triatriatum may be associated with major congenital cardiac problems. In adults, it is often an isolated finding.[2] Treatment depends upon the symptoms present and may include medical or surgical approaches.[3]

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

  • 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 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.
  • 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 Cor triatriatum. Click on the link to view a sample search on this topic.


  1. Cor Triatriatum. National Organization for Rare Disorders (NORD). 2003; https://www.rarediseases.org/rare-disease-information/rare-diseases/byID/136/viewAbstract. Accessed 3/21/2013.
  2. Shirani J, Acharya YR, Kalyanasundaram A, Pourmoghadam KK. Cor Triatriatum. Medscape Reference. June 2012; https://emedicine.medscape.com/article/154168-overview. Accessed 3/21/2013.
  3. Pierre Nagib Nassar, Righab Haidar Hamdan. Cor Triatriatum Sinistrum: Classification and Imaging Modalities. Eur J Cardiovasc Med. January 2011; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3286827/. Accessed 3/21/2013.