Flashcards in Defects in Cardio Embryo Deck (14):
What is the abnormality of folding that essentially produces a mirror image of a normal
How does flow (shunting) occur in terms of compliance?
From a less compliant to a more compliant system
What common action of the baby can raise pulmonary pressure?
Which ventricle is typically more compliant? What would this result in?
RV; left to right shunting
Review the steps in creating the ventricular septum
1. Right and left bulbar ridges spiral down dividing the conus
2. Muscular septum “grows upwards”
3. Endocardial cushions fuse dividing the AV canal
4. Inferior endocardial cushion grows to fill the boundary
In an interventricular defect, which way is blood likely to flow? What is the
complication with this? Will the baby be blue?
Interventricular defect - blood more likely to go from left-right to go down pressure
gradient. Blood entering the lungs is slightly more oxygenated
PROBLEM -overcirculation of lungs
*But babies are not blue because oxygenated blood is mixing with deoxygenated blood
Shunting in a VSD occurs predominantly in _____.
Volume loads what in ASD? What does the volume load in VSD?
RA, RV, lungs;;; LA, LV, lungs
What are the basic elements of the Tetralogy of Fallot?
(1) Pulmonary stenosis (2) Aortic Override (3) VSD (4) Right Ventricular Hypertrophy
Explain development of the Tetralogy of Fallot
In other words-- during spiral division, division is not perfectly in midline, and pulmonary
artery doesn’t get as much space -- pulmonary stenosis.
VSD results from pulmonary septum not coming down in the right place
Lack of membranous septum results in aortic override
Blood from right ventricle typically pumps into pulmonary artery, but there is stenosis and
need to build up more pressure so don’t go into aorta so you get right ventricular
Right to left shunt - because there is so much more pressure on the right side since right ventricle is struggling hard to push against small pulmonary artery, and blue blood in
ventricle is going to start going into aorta
Why are babies with tetralogy of Fallot bluer at rest?
Low systemic resistance
How do Tet. of Fallot kids often adapt to fix?
Squat to try and increase systemic resistance and decrease shunting
What does a lack of spiraling/twisting in development of the AP septum result in?
What must a baby with this defect have to live after birth?
Transposition of the vessels. pulmonary artery coming off left ventricle. aorta coming off right ventricle
Blue blood is recycled w/o getting oxygenated
Red blood is recycled to lungs
Baby must have mixing of blood through patent foramen ovale, patent ductus arteriosus