Types of Cyanotic Congenital Heart Disease that Present in the First Week of Life,
by Dr. Michael Freed.
The first type is transposition of the great arteries
with an intact ventricular septum.
And these kids have relatively normal parts.
But instead of the pulmonary artery coming off
the right ventricle, the aorta comes off the right ventricle,
and the pulmonary artery comes off the left ventricle.
So blood from the body goes right atrium, right ventricle,
out the aorta, back to the body.
Blood from the lungs-- left atrium, left ventricle,
out to the pulmonary artery.
And these kids, to survive, need some kind
of mixing, usually at the ductile level
and the atrial level.
But these kids come in very sick in the first few days of life.
The second is total anomalous pulmonary venous connection.
These are kids who the pulmonary veins never
get back to the left atrium.
So they do okay in utero, because there is usually
some connection from the common pulmonary vein behind the heart
to the right superior vena cava or left superior vena cava
or umblical vitelline system.
When they're born, all of a sudden,
they can't get blood out of the lungs.
The blood backs up into the lungs.
They get very high pulmonary venous pressure and go
into pulmonary edema.
Ebstein's, which is an abnormality
of the tricuspid valve.
So they get severe tricuspid regurgitation,
elevating their right atrial pressure.
And they shunt right to left at the atrial level.
Tricuspid atresia-- so in tricuspid atresia,
the tricuspid valve never forms.
The right ventricle is either very small or nonexistent.
Blood comes back to the body into the right atrium,
can't get through here, goes across the foramen ovale
into the left atrium, left ventricle,
out the aorta to the body.
Some of it goes through the ductus arteriosis,
out to the lungs, where it gets oxygenated, and comes
back again.
So in utero, this is not a problem.
And after birth, this isn't a problem.
But when the ductus arteriosis starts closing,
then the amount of blood going through here diminishes.
The blood going to the lungs to get oxygen is reduced.
And gradually, the arterial saturation will decrease.
There will be more hypoxemia.
Pulmonary atresia, intact ventricular septum.
So these kids have no outlet to the right ventricle.
Usually, right ventricle doesn't grow very much.
So these kids, blood comes back from the body, right atrium,
can't get out this way, goes out this way, out this way.
And again, these kids are dependent on their ductus
arteriosus for their blood flow.
And when the ductus arteriosus closes,
they get into difficulty.
Pulmonary stenosis-- we talked about before.
If you look at pulmonary stenosis,
these kids have severe right ventricle outflow tract
obstruction.
The right ventricle has to generate a higher pressure
to pump blood out.
And if it starts having difficulty generating
that higher pressure, by Starling's law,
it increases preload.
If you increase the preload in the ventricle,
the atrial pressure goes up.
And in the newborn period, if the right atrial pressure
exceeds the left atrial pressure,
you start shunting right-to-left and you end up with cyanosis.
Tetralogy of Fallot with pulmonary stenosis,
or Tetralogy of Fallot with pulmonary atresia.
So with these kids with a ventricular septal
defect and pulmonary stenosis, blood coming back
from the body, right atrium, right
ventricle, difficulty going out here.
So some goes out to the body.
Some goes through here to the lungs and back again.
With pulmonary atresia, nothing goes out this way.
And they're dependent on the ductus arteriosus.
So as mentioned before they get into difficulty when the ductus closes.