Cyanotic heart defects Flashcards
what are the respiratory causes of desaturation?
V/Q mismatch
obstruction
weakness of respiratory muscles
how do you augment pulmonary blood flow?
keep the PDA open
what is the use of the hyperoxitest?
to determine if cause of cyanosis is due to the heart or lungs
what is the role of PGE-1?
maintain patency of ductus arteriosus
what are the five Ts of cyanotic heart disease?
truncus arteriosus (1) transposition of the great arteries (2) tricuspid atresia (3) tetralogy of fallot (4) total anomalous pulmonary venous return (5)
what are the PE findings (2) in D-transposition?
- cyanotic full term male in no apparent distress
2. S2 is single and loud because aorta is anterior to PA
what test confirms the anatomy in D-transposition?
echo
what is the medical management for D-transposition (5)?
- PG
- correct acidosis
- oxygen
- balloon atrial septostomy
- anti-congestive
what is the rashkind procedure used for? how does it work?
D-transposition
special catheter advanced into heart via umbilical or femoral vein and advanced across restrictive patent foramen ovale - balloon is ripped back into RA
what are the four anomalies of tetralogy of fallot?
- large VSD
- overriding aorta
- RV outflow obstruction (sub-pulmonary / pulmonary stenosis)
- RV hypertrophy
what is the pathophysiology of tetralogy of fallot (3)?
- RV outflow obstruction limits pulmonary blood flow
- right to left shunt across VSD into aorta
- degree of cyanosis depends a lot on the degree of RV outflow obstruction
what is present at birth in children with tetralogy of fallot?
cyanosis murmur (RV outflow obstruction - not from VSD)
what are the EKG findings in tetralogy of fallot?
RAD
RVH
what is the classic morphology of the heart on CXR in tetralogy of fallot?
boot shaped
what is the pathophysiology of tet spells?
spasm of RV outflow tract increases right to left shunt across VSD, leading to worsening cyanosis and acidosis
what is the anatomy (4) of tricuspid atresia?
- absent tricuspid valve
- RV is hypoplastic
- majority of cases have either pulmonary atresia or pulmonary stenosis
- small VSD is often present
what is the pathophysiology of tricuspid atresia?
- RA blood must cross atrial septum (complete mixing in LA)
- pulmonary blood flow is usually limited
what test is significant for tricuspid atresia? why?
EKG - shows left superior axis
what is main source of pulmonary blood flow in tricuspid atresia?
ductus arteriosus
what is the ultimate surgical goal for tricuspid atresia?
fontan procedure
what is fontan circulation? what drives blood to lungs?
IVC and SVC directly to pulmonary arteries
systemic venous pressure
what is the anatomy in truncus arteriosus (2)?
- only a single arterial trunk leaves the heart, giving rise to systemic, pulmonary, and coronary circulations
- large VSD is present directly below the arterial trunk
what is the pathophysiology of truncus arteriosus (3)?
- both ventricles empty into great artery
- pulmonary over-circulation (PVR less than SVR)
- pressure overload to lungs
what is the surgical management for truncus arteriosus?
- direct LV flow out the truncal valve via patch closure of VSD
- disconnect and attach to RV-PA conduit
what is the pathophysiology (2) of total anomalous pulmonary venous return?
- complete mixing in RA
2. veins can be obstructed
which test is helpful in evaluating for obstruction in total anomalous pulmonary venous return?
CXR
