Ostium primum atrial septal defect

Ostium primum atrial septal defect
Classification and external resources
Schemating drawing showing the location of different types of ASD, the view is into an opened right atrium. HV: right ventricle; VCS: superior caval vein; VCI: inferior caval vein; 1: upper sinus venosus defect; 2: lower sinus venosus defect; 3: secundum defect; 4: defect involving coronary sinus; 5; primum defect.
ICD-10	Q21.2
ICD-9	745.6
DiseasesDB	1090
eMedicine	ped/1685

The ostium primum atrial septal defect (also known as an endocardial cushion defect) is a defect in the atrial septum at the level of the tricuspid and mitral valves. This is sometimes known as an endocardial cushion defect because it often involves the endocardial cushion, which is the portion of the heart where the atrial septum meets the ventricular septum and the mitral valve meets the tricuspid valve.

Endocardial cushion defects are associated with abnormalities of the atrioventricular valves (the mitral valve and the tricuspid valve). These include the cleft mitral valve, and the single atrioventricular valve (a single large, deformed valve that flows into both the right ventricle and the left ventricle).

Endocardial cushion defects are the most common congenital heart defect that is associated with Down's syndrome.

Classification

A defect in the ostium primum is occasionally classified as an atrial septal defect,^[1] but it is more commonly classified as an atrioventricular septal defect^[2][3]

References

1. ^ "Atrial Septal Defect Types - Mayo Clinic". http://www.mayoclinic.org/atrial-septal-defect/types.html. Retrieved 2007-10-14. 
2. ^ Fix, James D.; Dudek, Ronald W. (1998). Embryology. Baltimore: Williams & Wilkins. pp. 52. ISBN 0-683-30272-8. 
3. ^ Q21.2

External links

• Down's Heart Group UK National charity related to heart conditions associated with Down's Syndrome.