Congenital Heart Disease II Flashcards
What is the most common congenital heart defect?
VSD. 20% of all congential heart defects.
There are four endocardial cushions. After fusion of the superior and _____ cushions you get a __________.
inferior
right and left atrioventricular canal
What is the most common type of VSD? Where in the heart do you get it?
perimembranous VSD
get it in the membranous portion of the intraventricular septum.
There are many kinds of muscular VSDs but muscular VSDs are the worst. T of F?
F. Well… depends. One small muscular VSD is almost never a problem. Its just a little hole. If you have a bunch of muscular VSDs then you could get issues.
What are the four endocardial cushions and what do they form parts of?
superior, inferior, Right, Left
They form parts of the mitral valve, tricuspid valve, and intraventricular septum (might want to go over this is more detail from the embryology lecture but wasn’t emphasized here).
How do you define a large defect VSD? Why can a large defect be problematic?
- large defects are the same diameter as the aortic orifice.
- Large defects are often unrestrictive meaning that there is often equalization of pressure between right and left ventricles.
T or F. PVR is usually lower than SVR
True. This is why, barring other complications, a VSD usually shunts L–>R.
In ASD we usually see dilation of the ______ while in VSD we usually see dilation of the ______. Explain.
Right ventricle
Left ventricle.
In VSD the blood is getting shunted to the right ventricle but it immediately goes into the lungs and then comes back to the LA. Then blood will build up in the LV and cause dilation. In ASD, the blood flows into the RA and then into the RV and causes RV dilation. Doesn’t make a ton of sense but just run with it.
Fetuses with VSD are______ until PVR falls at birth (even with large defects). How does a fall in PVR relate to altitude?
asymptomatic
fall in PVR is delayed at high altitude.
People with VSD present with a holosystolic murmur that is loudest where?
Left lower sternal border
T or F larger VSDs are louder.
F. think of it like putting your thumb over a garden hose. The smaller the hole you make the more pressure that results and the louder it is. smaller hole=louder murmur. This means that sometimes really big VSDs don’t show up on physical exam. It also means that a murmur that gets louder isn’t necessarily a bad thing.
What can a murmur which gets louder mean in VSD?
closing of the VSD and low PVR (meaning that there is also low pulmonary pressure). These are good things. See last card. This also means that a murmur which goes away can be a bad thing (hole getting bigger).
Gold standard for diagnosing VSD?
Echo (same as ASD).
How can VSD cause aortic insufficiency?
The aortic valve can get sucked into the VSD and cause aortic regurgitation.
How do you treat VSD?
- if asymptomatic don’t worry about it.
- In infancy just treat symptoms– diuretics to keep lungs clear and avoid PE from excessive pulmonary blood flow.
- Device closure is available (percutaneous) if the hole is small enough.
- secondary changes (aortic regurg.), persistent symptoms, and pulmonary vascular changes are all indications for surgery.
At what stage of getting eisenmengers syndrome does VSD become pretty much irreversible.
muscularization of the pulmonary arterioles.
summary
VSD
- magnitude and direction of shunt depend on ______.
- PVR is ____ than SVR.
- Murmur is caused by _______.
- small defects can have _____ murmurs than large defects.
- size of defect and difference in pulmonary and systemic resistance.
- lower (L–>R shunt)
- flow across the defect (pressure difference between RV and LV– this is different from ASD).
- louder
embryological basis of TOF is __________. This results in what four things?
anterior and rightward deviation of infundibular septum.
- right ventricular outflow tract obstruction
- right ventricular hypertrophy
- dextraposition of aorta over VSD
- VSD
TOF is the most common what?
cyanotic congenital heart lesion.
What dictates urgency of surgical repair?
amount of RV outflow tract (RVOT) obstruction.
Severe RVOT may necessitate what?
prostaglandin infusion and neonatal repair. Otherwise you can manage as an outpatient and repair at 2-4 months.
If outflow obstruction is sever in TOF where is most pulmonary blood flow derived from?
ductus arteriosus. This is why we sometimes give the baby PGs–> keep DA open until we can decide how to treat the baby.
- R–>L shunt occurs when _______ and results in ______.
2. L–>R shunt occurs when _______ and results in ______.
- -RV outflow resistance is higher than systemic vascular resistance. results in cyanosis (blue baby).
- RV outflow resistance is less than systemic vascular resistance. Results in no cyanosis (pink baby).
What is the classic presentation of TOF.
blue baby with loud murmur.
Why do people with TOF squat during gym class?
attempting to increase SVR and improve pulmonary blood flow.
What are 2 physical exam findings that are highly suggestive of coarctation of aorta?
- decreased femoral pulses
- upper and lower extremity BP discrepancy
these two things were mentioned a bunch. This will probably be on the test.
Also recognize that poor lower extremity blood flow can lead to leg pain and decreased flow to bowel (necrotizing enterocolitis).
Why will newborns with coarc. sometimes be asymptomatic?
patent DA allows adequate post-coarc. flow. as ductus closes get tachypnea, diaphoresis, and poor feeding.
DA makes diagnosing coarc. difficult but can save the child.
What does treatment of coarc. depend on? What are the classic treatments for various age groups?
depends on anatomy of coarc.
- infants/young children= surgery
- older children/adults=balloon angioplasty/stent
