Cardiology Flashcards
O2 sat in chambers of fetal circulation.
Where is O2 sat highest? Lowest?
PBF ~ 7 - 15% 2nd trimester
30% 3rd trimester (lung growth so increased PBF)
20% around 38 weeks (more O2 so constricts?)
66% CO RV vs 33% LV
Left - because receiving DV blood flow (from UVC oxygenated blood) primarily without mixing in much “used” deoxygenated blood + little bit of blood from lungs
Increase ductus venosus - dilates.
Decrease HR, RR, CO
Fetus goes in hibernation mode - relies on maternal thermoregulation, decrease GI absorption, decreased RR, decrease renal tubular absorption
Preferentially sends blood to head, heart, adrenal glands (by dilating ductus venosus to increase blood to RA -> LA via FO). Abd circumference decrease in FGR fetuses (b/c less BF to those organs) and elevated MCA (diastolic flow increased as more BF to brain)
Note-tricuspid valve very sensitive to hypoxemia (therefore, babies with HIE can have TR)
- Increase PBF via breathing RA (dilates pulm vessels and decrease PVR)
- Closure of FO (increase LA pressure due to increase pulm BF and PV return so then closes; also distal SVR will increase LA pressure)
- Closure of DA (oxygen exposure of ductal tissue with constrict it, decrease PGE production (detached from placenta) and metabolism (from lung that is working more), decrease bradykinin (helps vasoconstrict)
UV constricts - because decrease blood flow
UA constricts - because increase O2 content
How does DCC work?
- continued blood flow from UV to LA/LV so continued preload while 1) lungs are aeration and increasing pulm BF and 2) not an acute drop in SVR so myocardium has time to start to handle a larger blood volume load
What influences ventricular wall stress?
Conceptualize Frank Starling curve
Frank starling curve - effect of increased and decreased preload
Frank starling curve - effect of increased and decreased afterload
PS, hypertelorism, downward slanting palpebral fissures, low at ears, short stature, short webbed neck, Percy’s excavation, cryotorchidism, cognitive delays, lymphedema
Noonan - most common cause of HOCM kids < 4 although most common cardiac defect with Noonan is PS
1 cyanotic congenital heart disease in infancy/childhood
ToF
1 cyanotic CHD in first week of life
TGA
describe early formation of cardiac tube
early cardiac embryology
mediator of cardiac development
mediators of septation
mediators of L-R differentiation
when does cardiac septation occur?
8 weeks
heterotaxy - what occurs
L atrial isomerism
- describe
- complications
R atrial isomerism
- describe
- complications
Reverse differential - infant pre ductal is 50% an post-ductal is 70%. Describe the scenario.
d-TGA with inadequate atrial or ventricular mixing and elevated PVR or LVOT (eg CoA).
Most common type of VSD. Which VSD types are more likely to close?
perimembranous
those with a muscular region (perimembranous or muscular)
Congenital heart disease - XR described as egg on a string
Scimitar syndrome X ray
- describe Scimitar syndrome
- complications
PAVPR (an anomalous pulm vein to RV)
Can develop pphn, can have some R pulm hypoplasia
Other associated anomalies