Cyanotic heart defects

Question 1

what are the respiratory causes of desaturation?

Answer 1

V/Q mismatch
obstruction
weakness of respiratory muscles

Question 2

how do you augment pulmonary blood flow?

Answer 2

keep the PDA open

Question 3

what is the use of the hyperoxitest?

Answer 3

to determine if cause of cyanosis is due to the heart or lungs

Question 4

what is the role of PGE-1?

Answer 4

maintain patency of ductus arteriosus

Question 5

what are the five Ts of cyanotic heart disease?

Answer 5

truncus arteriosus (1) 
transposition of the great arteries (2) 
tricuspid atresia (3) 
tetralogy of fallot (4) 
total anomalous pulmonary venous return (5)

Question 6

what are the PE findings (2) in D-transposition?

Answer 6

1. cyanotic full term male in no apparent distress

2. S2 is single and loud because aorta is anterior to PA

Question 7

what test confirms the anatomy in D-transposition?

Answer 7

echo

Question 8

what is the medical management for D-transposition (5)?

Answer 8

1. PG
2. correct acidosis
3. oxygen
4. balloon atrial septostomy
5. anti-congestive

Question 9

what is the rashkind procedure used for? how does it work?

Answer 9

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

Question 10

what are the four anomalies of tetralogy of fallot?

Answer 10

1. large VSD
2. overriding aorta
3. RV outflow obstruction (sub-pulmonary / pulmonary stenosis)
4. RV hypertrophy

Question 11

what is the pathophysiology of tetralogy of fallot (3)?

Answer 11

1. RV outflow obstruction limits pulmonary blood flow
2. right to left shunt across VSD into aorta
3. degree of cyanosis depends a lot on the degree of RV outflow obstruction

Question 12

what is present at birth in children with tetralogy of fallot?

Answer 12

cyanosis 
murmur (RV outflow obstruction - not from VSD)

Question 13

what are the EKG findings in tetralogy of fallot?

Answer 13

RAD

RVH

Question 14

what is the classic morphology of the heart on CXR in tetralogy of fallot?

Answer 14

boot shaped

Question 15

what is the pathophysiology of tet spells?

Answer 15

spasm of RV outflow tract increases right to left shunt across VSD, leading to worsening cyanosis and acidosis

Question 16

what is the anatomy (4) of tricuspid atresia?

Answer 16

1. absent tricuspid valve
2. RV is hypoplastic
3. majority of cases have either pulmonary atresia or pulmonary stenosis
4. small VSD is often present

Question 17

what is the pathophysiology of tricuspid atresia?

Answer 17

1. RA blood must cross atrial septum (complete mixing in LA)
2. pulmonary blood flow is usually limited

Question 18

what test is significant for tricuspid atresia? why?

Answer 18

EKG - shows left superior axis

Question 19

what is main source of pulmonary blood flow in tricuspid atresia?

Answer 19

ductus arteriosus

Question 20

what is the ultimate surgical goal for tricuspid atresia?

Answer 20

fontan procedure

Question 21

what is fontan circulation? what drives blood to lungs?

Answer 21

IVC and SVC directly to pulmonary arteries

systemic venous pressure

Question 22

what is the anatomy in truncus arteriosus (2)?

Answer 22

1. only a single arterial trunk leaves the heart, giving rise to systemic, pulmonary, and coronary circulations
2. large VSD is present directly below the arterial trunk

Question 23

what is the pathophysiology of truncus arteriosus (3)?

Answer 23

1. both ventricles empty into great artery
2. pulmonary over-circulation (PVR less than SVR)
3. pressure overload to lungs

Question 24

what is the surgical management for truncus arteriosus?

Answer 24

1. direct LV flow out the truncal valve via patch closure of VSD
2. disconnect and attach to RV-PA conduit

Question 25

what is the pathophysiology (2) of total anomalous pulmonary venous return?

Answer 25

1. complete mixing in RA | 2. veins can be obstructed

Question 26

which test is helpful in evaluating for obstruction in total anomalous pulmonary venous return?

Answer 26

CXR