congenital heart defects: PDA

Question 1

most common defect associated with

Answer 1

maternal rubella syndrome

Question 2

PDA are prominent in

Answer 2

females

Question 3

abnormal transcription factors

Answer 3

TFAP2B-neural crest transcription factor

associated with Char syndrome and PDA

Question 4

infants with high incidence

Answer 4

preterm

<28 weeks gestation

Question 5

embryological from

Answer 5

VI pharyngeal arch artery

Question 6

pathophysiology behind PDA

Answer 6

ductus arteriosus constricts in response to increased pO2 and decreased PGE2 in arterial blood shortly after birth
-not closed-> blood shunted from aorta thru ductus into pulmonary artery

Question 7

why does persistent DA remain open after a few weeks?

Answer 7

• deficiency of endothelial and muscular layer of vessel, regulator proteins to direct fibrosis
• or, another cardiac lesion needing this channel blood flow

Question 8

what causes flow thru PDA?

Answer 8

decreasing pulmonary VR and lower diastolic pressures in pulmonary artery causes flow through the PDA
-initially in systole (systolic murmur) then in both systole and diastole (continuous)

Question 9

large PDA will?

Answer 9

increase LV pressure during diastole which will increase LA pressure and then pulmonary venous pressure

Question 10

clinical presentation of PDA

Answer 10

• normal at birth

- ALL INFANTS WITH PDA WITH SHOW INCREASED PERIPHERAL PULSE PALPATIONS

Question 11

small PDA

Answer 11

at 2-6 weeks:
systolic murmur
maybe pulses may be present in an asymptomatic infant

Question 12

large lesion PDA

Answer 12

at 2-6 weeks:
-signs of CHF
-LV thrust
-continuous murmur (diastolic) at ULSB, radiates to back
-liver enlarged
-peripheral pulse bounding 
diastolic rumble at apex

Question 13

small PDA will have a normal

Answer 13

CXR and ECG

Question 14

CXR

Answer 14

increased pulmonary artery, aorta, pulmonary vascular markings,
-may have increased LV and LA if large

Question 15

ECG

Answer 15

normal to LVH

Question 16

Echo

Answer 16

• normal LA and LV size with small shunt
• large shunt gives increased LV and LA size (La:Ao root ratio increased)
• visualized by suprasternal notch view

Question 17

PDA prognosis: small lesion

Answer 17

normal life span

-maybe CHF late in life, bacterial endocarditis, pulmonary or systemic embol

Question 18

PDA prognosis: large

Answer 18

• risk for: CHF, bacterial endocarditis, pulmonary or systemic emboli
• pulmonary HTN
• eisenmonger’s syndrome
• palpitations
• ductal rupture

Question 19

treatment

Answer 19

closure of ALL lesions
-closure reverses cardiac failure: continuous murmur is gone leaving systolic flow murmur (turbulence in dilated pulmonary artery), LV size and function improves