Search results
Results from the WOW.Com Content Network
Atrial septal defect (ASD) is a congenital heart defect in which blood flows between the atria (upper chambers) of the heart.Some flow is a normal condition both pre-birth and immediately post-birth via the foramen ovale; however, when this does not naturally close after birth it is referred to as a patent (open) foramen ovale (PFO).
Most ASD cases are due to the ostium secundum which can happen when the secundum septum doesn’t grow enough during development This actually accounts for about 10-15% of all congenital heart defects and is the most common congenital heart defect in adults.
For the septum secundum, its inadequate growth can cause atrial septal defect since it is supposed to grow and eventually overlap the foramen secundum so as to form the oval foramen. As the right atrial pressure is normally lower than the mean left atrial pressure, a persisting ostium secundum causes usually a left-to-right shunt (meaning that ...
An Atrial septal defect is a relatively common heart malformation that occurs when the interatrial septum fails to develop properly. Persistence of the ostium secundum is the most common atrial septal defect. [3] Additionally, in a subset of the population, the foramen ovale is not overtly patent but the two septa have not fused.
The ostium primum atrial septal 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.
Coalescence of these perforations will form the ostium secundum (second opening), which allows blood to flow freely from the right atrium to the left. When the right of the atrium expands due to the incorporation of the pole of the sinus, a new fold appears, called the septum secundum. At its right side it is fused with the left venous valve ...
The gap below it is known as the ostium primum (from Latin 'first opening'), and becomes increasingly small. The septum primum eventually fuses with the endocardial cushion, closing the ostium primum off completely. Meanwhile, perforations appear in the superior part of the septum primum, forming the ostium secundum (from Latin 'second opening').
The septum secundum is a muscular flap that is important in heart development. It is semilunar in shape, and grows downward from the upper wall of the atrium immediately to the right of the septum primum and ostium secundum. It is important in the closure of the foramen ovale after birth.