Cardiac embryology diseases

Question 1

what is patent ductus arteriosus

Answer 1

persistence of distal left 6th aortic arch

Question 2

where is patent ductus arteriosus incidence incr

Answer 2

1) babies born at elevation >9000
2) maternal rubella
3) infants <29 weeks gestation (1/3 spontaneous closure)

Question 3

when does PDA functionally close

Answer 3

10-15 hrs after birth

delayed at high elev

Question 4

when does PDA anatomically close

Answer 4

2nd-3rd wk of life

Question 5

how does DA close

Answer 5

ductus = fewer elastic fibers and more muscular than aorta and pulm artery

increased PaO2 after birth causes contraction of spiral muscular fibers in PDA

Question 6

why does DA not close in premature

Answer 6

contraction of spiral muscular fibers is weakened in premature

Question 7

vascular remodeling after DA closes

Answer 7

1) form internal elastic membrane of ductus frag
2) intima and media proliferate
3) mucoid lakes form in intima and media
4) hyaline mass occludes lumen

Question 8

why does DA stay open

Answer 8

PGE2 (vasoactive) = keeps DA open

Question 9

how do you keep DA open?

Answer 9

administer PGE2 IV

Question 10

where is PGE2 produced

Answer 10

from ductal wall

or placenta

Question 11

what is clinical presentation of PDA

Answer 11

depends on size of “shunt”

Question 12

what is shunt

Answer 12

connection btwn 2 chambers and vessels

Question 13

what is left-to-right shunt imply?

Answer 13

blood flow from systemic into pulmonary chamber

Question 14

when blood flows from systemic to pulm, what shunt is that

Answer 14

left-to-right

Question 15

what are systemic chambers in heart

Answer 15

1) pulm veins
2) left atrium
3) left ventricle
4) aorta

Question 16

what are pulm chambers in heart

Answer 16

1) systemic veins
2) right atrium
3) right ventricle
4) pulm arteries

Question 17

are shunts equal

Answer 17

NO

Question 18

what does magnitude of shunt depend on (2 things)

Answer 18

1) size of PDA

2) resistances of aorta and pulm artery

Question 19

what is more common shunt

Answer 19

left to right

because aortic resistance > pulm resistance so blood go from aorta –> pulm artery

Question 20

what if neonates have high pulm vascular resistance

Answer 20

PDA flow from right to left or bidirectional

Question 21

when would a neonate have high pulm vascular resistance

Answer 21

1) premature
2) lung disease
3) born at altitude

Question 22

what is clinical presentation of small PDA

Answer 22

asymptomatic

Question 23

what is clinical presentation of moderate-large PDA

Answer 23

1) respiratory effect (pulm edema/hemorrhage)
2) CHF
3) feeding intolerance –> bowel ischemia (necrotizing enterocolitis)
4) hemorrhage/storke
5) death

Question 24

what is clinical presentation of PDA in older infant/young child

Answer 24

1) hoarse cry
2) hx of pneumonia
3) incr work breathing
4) diaphoresis with activity and feeding

Question 25

physical exam of large PDA with left to right flow

Answer 25

1) wide pulse pressure
2) bounding pulses (palpable palmar pulse)
3) incr work breathing
4) hyperactive precordium

Question 26

what is classic murmur of PDA

Answer 26

continuous machine murmur along left upper sternal border (may have diastolic rumble if shunt large

Question 27

where do you hear murmur of PDA

Answer 27

left upper sternal border

Question 28

why could you not hear murmur of PDA

Answer 28

low velocty

tiny shunt

Question 29

if there is pulm HTN with PDA what else would you hear

Answer 29

accentuated P2

systolic ejection

Question 30

how do you dx PDA

Answer 30

H&P

chest radiograph

• can be normal if PDA small
• incr pulm vascular marking, large LA and LV

echo

Question 31

how do you manage PDA

asymptomatic neonate

Answer 31

conservate

Question 32

how do you manage PDA

symptomatic neonate

Answer 32

COX inhib (IV indomethacin or IV ibuprofen lysate)

surgical ligation via lateral thoracotomy

Question 33

how do you manage PDA

symptomatic older child or

Answer 33

percutaneous occlusion

Question 34

how do you manage PDA

asymptomatic oldr child

Answer 34

murmur –> percutaneous closure

silent –> no need to intervent

Question 35

why do you use cox inhibitors

Answer 35

block prostaglandin (PGE2) (that keeps shunt open)

Question 36

for cox inhibitors when would you use indocin

Answer 36

protective against intraventricular hemorrhage but decr blood to kidney and brain

Question 37

for cox inhib when would you use ibuprofen lysine

Answer 37

renal disease/insufficiency

Question 38

when is cox inhib most effect

Answer 38

first week but wait after 48 hrs to see if spontaneous closure

Question 39

how does PDA progress

Answer 39

1) if large –> Eisenmenger’s - irrev pulm HTN

2) incr risk of subacute bacterial endocarditis

Question 40

what does magnitude of PDA shunt depend on (2 things)

Answer 40

1) size of PDA

2) resistances of aorta and pulm artery

Question 41

physical exam of large PDA with left to right flow

Answer 41

1) wide pulse pressure
2) bounding palmar pulses
3) incr work breathing
4) hyperactive precordium

Question 42

what is classic murmur of PDA

Answer 42

continuous machine murmur along left upper sternal border (may have diastolic rumble if shunt large

Question 43

how do you manage PDA

symptomatic older child

Answer 43

percutaneous occlusion

Question 44

how do you manage small PDA

asymptomatic older child **skip

Answer 44

murmur –> percutaneous closure
b/c incr risk of bacterial endocarditis

silent –> no need to intervent