101714 congenital heart disease cases Flashcards
hypoplastic left heart syndrome
left ventricle hypoplasia with mitral/aortic atresia
why do fetuses with hypoplastic left heart syndrome do well?
because of the ductus arteriosus
after birth, doesn’t do well–needs surgery
when would cardiogenic shock present in a pt with hypoplastic left heart syndrome
when the PDA is nearly fully closed
pathophysiology of aortic coarctation
obstruction to flow causes increased LV afterload, resulting in increased wall stress leading to compensatory ventricular hypertrophy leading to congestive heart failure leading to shock/metabolic acidosis/organ failure
fetal flow pattern for aortic coarctation
blood flow through aortic isthmus is only 10% of the total CO in FETAL period
ductal flow is right to left
R heart carries 2/3 of the volume load of total CO
even if isthmus was completely atretic, there would be blood supply to all tissues, so the fetus does well
genetic influences for aortic coarctation?
Turner XO syndrome
Noonan syndrome
what intracardiac lesion can aortic coarctation be associated with?
bicuspid aortic valve
common presentations of aortic coarctation
fetal cardiac abrnomalities
infant with CHF
child with arterial systolic HTN
child with murmur
how does aortic valve develop?
from 3 swellings of subendocardial mesenchyme
albnormal cavitation of these swellings results in leaflet fusion and stenosis
aortic valve disease is progressive: true or false
true, due to calficication and fibrosis of valve leaflets, and aortic insuff may develop due to annular dilation
what is the classic aortic valve stenosis murmur
harsh systolic crescendo-decrescendo murmur heard at R upper sternal border and radiating into neck
effect of mild to moderate aortic stenosis on fetal circulation and postnatal?
no effect on fetus
postnatal: normal
severe aortic stenosis-effect on fetal circulation and postnatal?
fetus: increased LVEDP, which reduces flow of highly oxygenated blood from umbilical vein into the LV and into the ascending aorta. umbilical venous blood high in O2 is instead directed through the RV where it mixes with SVC blood which is low in O2 and then is directed through ductus arteriosus into descending aorta and retrograde into ascending aorta (results in blood lower in O2 supplying brain and coronary arteries)
postnatal-dependent on ductus arteriosus for sytemic blood flow
what is the most common genetic association for tetrology of fallot?
DiGeorge syndrome
the most common cyanotic congenital heart disease
tetralogy of fallot
what is seen more commonly in infants of diabetic mothers?
TGA
what causes TGA?
probably abnormal conotruncal rotation as septation occurs
what happens with TGA at birth?
marked cyanosis-degree can be variable depending on associated lesions, however. but it is usually profound
what are potential sources of intercirculatory mixing for TGA?
atrial (PFO, ASD) ventricular level (VSD-present in 40 % of TGA) arterial level (PDA)
postnatal circulation-what happens to SVR and PVR?
SVR increases PVR decreases (with ventilation)
difference btwn shunting and mixing?
shunting creates a route,
however, mixing requires perhaps more than just one route for effective distribution
O2 rich blood from placenta enters umbilical vein to ductus venosus with preferential flow through what structure in heart in the fetal circulation?
PFO
in terms of outputs, RV and LV have what percentages in fetal circulation?
RV-60
LV-40
transition from fetal to newborn circulation is described by what?
parallel flow becomes flow in series
why does the fossa ovale valve close after birth?
because all the RV output is now going to the lungs, which increases LA flow. the pressure in LA causes fossa ovale to close
in newborn, if ductus arteriosus remains open, what happens circulation wise
pulmonary resistance drops. pressure in aorta becomes becomes a lot higher than pressure in pulmonary artery. blood flows from aorta to PA. can lead to heart failure and poor growth
if newborn has a PDA but blood continues to flow from PA to aorta, how would you recognize this?
baby’s legs would be blue
in order for hypoplastic left heart syndrome baby to survive after birth, what 2 additional defects must exist?
atrial septal defect and patent ductus arteriosus
what cardiac defect is present in 40% of pts with Down syndrome
AVSD
fusion of superior and inferior endocardial cushions result in what
division of AV canal into right and left AV orifices
also participate in formation of membranous portion of interventricular septum and closure of primum septum
single S2?
suggests possibly one outflow tract
after birth, what problems do you get with truncus arteriosus?
as pulmonary vascular resis decreases, blood flow prefers to go to lungs–can lead to heart failure or pulmonary overcirculation
how can truncus arteriosus present?
increased or decreased pulmonary blood flow
decreased pulmonary blood flow and no regurgitation is a rare presentation
heart failure symptoms in baby
tachypnea
hepatomegaly
poor feeding
diaphoresis
truncus arteriosus -40% is associated with?
DiGeorge syndrome
second most common congen heart defect
ASD
exam finding for ASD?
fixed splitting of S2 b/c RV is always big
