Endocardial Cushion Defects Flashcards
Endocardial Cushion defects are a result of what?
Growth failure in the development of the atrioventricular endocardial cushions.
What is another name for endocardial cushion defect?
Partial or Complete AV canal defect
How do the endocardial cushions grow?
Convex towards the atria and IAS
Concave towards the ventricles and IVS
Endocardial cushion defects, ASD’s, and VSD’s are common in babies born with _____ ________.
Down’s Syndrome (Trisomy 21)
The endocardial cushions help form ____, ____, ____, ____, and ____.
Interatrial septum, Interventricular septum, anterior leaflet of Tricuspid valve, part of septal leaflet of Tricuspid valve, and anterior leaflet of Mitral valve.
A complete AV canal involves ______________.
All 4 valves and chambers.
A complete AV canal may also have a ________ and a ________.
Large membranous VSD and a large primum ASD.
With a complete AV canal, the ____ and ____ can be merged so there is _____________.
Mitral valve
Tricuspid valve
Just one valve
With complete AV canal, there can be _______, the __________ is usually incompetent, and there can be _____________.
Shunting at both levels
Aortic valve
Aortic insufficiency
Some associated defects with complete AV canal are: (6 examples)
Primum ASD, fenestrations, sinus venosus ASD, VSD, cleft Mitral valve
What is a partial AV canal?
When the endocardial cushions partially fuse resulting in the division of the av canal into R/L atrioventricular ostia.
Associated with partial AV canals are: a)____ b)____ c)____ d)____
a) R/L ostium b) Primum ASD c) cleft in anterior leaflet of MV d) RV volume overload
What type of shunting is there with complete AV canal?
Shunting at both levels. 4 chamber mixing.
In complete AV canal defects, the aortic valve is usually _______ and there can be _____ _______.
Incompetent
Aortic Insufficiency
Due to the 4 chamber mixing, O2 sats are probably in the ___ and baby may be a bit _______.
80’s
Cyanotic
With complete AV canal defects the ____ ____ and _____ _____ may be malformed or not formed at all.
Mitral valve
Tricuspid valve
Associated defects with complete AV canal defects:
Other types of ASD or fenestrations, VSD, cleft mitral valve
How are partial AV canal defects formed?
Endocardial cushions partially fuse resulting in the division of the AV canal leaving a right and left ostium.
Associated defects of partial AV canal are:
Primum ASD, cleft in anterior leaflet of mitral valve, possibly VSD.
What happens to the RV in partial AV canal defects?
There is an RV volume overload due to the RA volume overload.
How does a volume overload affect the RV?
The RV chamber will dilate over time, become hyperdynamic, and pressures will increase.
Why is there a fixed/split S2?
It’s all the same. Pressures are the same throughout.
The time interval between the A2 and P2 are fixed unlike the variable physiologic split found in a healthy heart.
What would produce a thrill?
High volume going out the PA can produce a palpable thrill.
Clinical findings for ECD’s: (10 examples)
Fixed/split S2, thrill, failure to thrive, fatigue, dyspnea, PHTN, growth retardation, CHF, decreased O2 sats, difficulty maintaining a stable BP
What does the 4 chamber mixing lead to?
RAE, LVE, RVE, RV volume overload
If a baby has ECD’s but is not ready for surgery, what palliative measure can be taken and why?
PA banding. This will reduce flow rate to the lungs, protecting them from risk of increased pulmonary vascular resistance.
Is the fixed/split S2 the only murmur?
There can be regurgitant murmurs as well. But with all of the swirling of flow, heart sounds may be difficult to distinguish.
Why do small defects sometimes go unnoticed?
No big changes in O2 sats. Baby can grow normally showing few symptoms. EKG and chest xray can look normal. Murmur may be mild.
What is the baby’s prognosis if ECD is not repaired (usually) within the first year?
Mortality rate is high. About 80% at 2 years due to increasing CHF and pulmonary vascular disease.
What is the goal of surgical repair?
To restore normal circulation by closing the ASD or VSD with patches. (these are too large for occluder devices)
Some surgical repairs for ECD’s include: (4 examples)
Reconstruct or replace TV and MV.
Remove PA band and any other palliative measures. Replace Ao valve if abnormal or incompetent.
Repair any other defects, ex:coarctation or RVOT obstruction.
Why would it be beneficial to postpone surgery if baby is stable enough?
It gives the pericardium time to thicken and strengthen for use in repairing defects.
What might be used to repair ECD’s?
Baby’s own pericardium or gortex grafts
