Atrial Septal Defect Flashcards
What is an atrial septal defect (ASD)?
L>R
(LA - RA)
What are the two main types of ASD?
- Secundum ASD
- Partial atrioventricular septal defects (AVSD or primum ASD)
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Ostium secondum, where the septum secondum fails to fully close, leaving a hole in the wall.
Ostium primum, where the septum primum fails to fully close, leaving a hole in the wall. This tends to lead to atrioventricular valve defects making it an atrioventricular septal defect.
What is the more common type of ASD?
Ostium secondum, where the septum secondum fails to fully close, leaving a hole in the wall.
Secundum ASD accounts for what percentage of ASD’s?
80%
What is a secundum ASD?
A defect of the atrioventricular septum involving the foramen ovale
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Ostium secondum, where the septum secondum fails to fully close, leaving a hole in the wall.
What is the foramen ovale?
Foramen ovale: This shunt connects the right atrium with the left atrium and allows blood to bypass the right ventricle and pulmonary circulation.
What may cause a secundum ASD?
?IGNORE?
- Failure of the septum secundum to develop
- Enlarged foramen ovale
What is a partial AVSD?
?IGNORE?
A defect in the inferior atrial septum (septum primum) and a regurgitant left atrioventricular valve leading to left to right communication
What are the risk factors for ASD?
- Female
- Family history
- Maternal alcohol consumption
- Down’s Syndrome
What is the common presentation of an ASD?
Commonly no symptoms
If symptoms are present, what might they be?
- Recurrent chest infections
- Wheeze
- Arrhythmias
What are the physical signs of an ASD?
- Ejection systolic murmur
- Fixed and widely split second heart sound
What sound is specifically heard in a partial AVSD?
Apical pansystolic murmur
Where is the ejection systolic murmur best heard?
Upper left sternal edge
What causes the ejection systolic murmur in ASD?
Increased flow across the pulmonary valve
