AVSD Flashcards
How are atrioventricular septal defects classified?
Can be complete or partial
Describe the anatomy of a complete AVSD
- Basically there is a hole in the centre of the heart
- This creates a passage between both artia and a passage between both ventricles
- This leads to obileration of valves so that there is only one valve on each side of the heart (between the atrium and ventricle) but this is often very leaky
How does a complete AVSD affect the blood flow within the heart?
How does it affect the anatomy?
- Since the left side of the heart is at a high pressure this causes blood to move from the left atrium and ventricle into the right atrium and ventricle
- This causes pulmonary hypertension
There is an increase in right ventricular compliance so the right atrium enlarges and the left atrium may too
Describe the anatomy of a partial AVSD
In partial AVSD there is only an atrial component and there are two leaky valves
What are the murmer characteristics of an AVSD?
- Systolic ejection murmer (increase flow through pulmonary valve and splitting of S2)
- Mid-diastolic murmer (LLSE - increased flow through mitral valve)
- Apical holosystolic murmer (radiating to the left axilla due to mitral insufficiency)
How does a neonate present with AVSD?
May be clear on antenatal screening
OR
With cyanosis at birth/heart failure at 2-3 weeks of life
How do you manage a neonate with an AVSD?
- Management to treat heart failure medically (diuretics)
- Sugical repair of the defect at 3-6 months
What increases your chances of AVSD?
DOWN’S SYNDROME
- 15-20% of children with down’s have AVSD
- 45% of children with down’s will have some form of congential heart disease
What will be seen on an ECG for a child with an AVSD?
- Left axis deviation
- Right atrial enlargement
- Bi-ventricular hypertrophy
- An incomplete RBBB
- A prolonged PR interval (1st degree heart block) - likely due to an abnormal AV node
