2. Fetal circulation
* Differs from adult circulation in several ways
* Almost all differences are attributable to the
fundamental defference in the site of gas exchange
Adult: lungs
Fetus: placenta
3. Course of Fetal Circulation
There are 4 shunts
in fetal circulation:
• Placenta
• Ductus venosus
• Foramen ovale
• Ductus Arteriosus
4. Some important aspects of fetal circulation:
1. The placenta receives the largest amount of combined
ventricular output(55%) and has the lowest vascular
resistance in the fetus
2. SVC drains the upper part of the body, IVC drains the
lower part of the body and placenta. O2 saturation in
the IVC(70%) is higher than in the SVC(40%)
3. Most of SVC blood goes to the RV. One third of the IVC
blood is directed by the crista dividens to the LA through
the foramen ovale, the remaining two third enters the
RV and PA.
4. Less oxygenated blood in the PA flows through the
widely open ductus arteriosus to the descending aorta
and then to the placenta for oxygenation.
5. Changes in Circulation
after Birth
The primary change in circulation
after birth is a shift of blood flow
for gas exchange from the
placenta to the lungs.
The placental circulation
disappears, and the
pulmonary circulation
is established.
6. 1. Interruption of the umbilical cord result in the following:
a. Systemic vascular resistance >>
as a result of the removal of
the very low resistance placenta
b. Closure of the ductus venosus
as a result of lack of blood return
from the placenta
2. Lung expansion results in the following:
a. Pulmonary vasc resistance <<,
pulmonary blood flow >> and
fall in PA pressure
b. Functional closure of foramen ovale
as a result of increased pressure
in the LA
c. Closure of patent ductus arteriosus
(PDA) as a result of increased
arterial oxygen saturation.
11. • Penyakit jantung bawaan (PJB):
– Non-sianotik terbesar
• Defek Septum Ventrikel (DSV) : 30%
• Defek Septum Atrium (DSA)
• Duktus Arteriosus Persisten (DAP)
• Stenosis Pulmonal
– Sianotik
• TOF (Tetralogi of Fallot)
• Atresia Pulmonal
• TGA (Tranposisi Great Artery)
• Single Ventrikel
12. Defek Septum Ventrikel
• Insiden
30 % dari PJB
• Anatomi
Defek subarteri : di bawah katup aorta dan pulmonal
Defek Perimembran: below aortic valve at pars
membranous septum
Defek Muskular
13. • Menurut besarnya diklasifikasikan:
– DSV kecil : < 5 mm2/m 2 luas permukaan tubuh
– DSV sedang : 5-10 mm2/m 2 luas permukaan tubuh
– DSV besar : defek lebih dari ½ diameter aorta atau
> 10 mm2/m 2 luas permukaan tubuh
35. Klinis
Defek Septum Atrium
- Asymptomatic
- Auskultasi:
- Bunyi jantung I normal atau mengeras
- Bising ejeksi sistolik di daerah pulmonum
- Bising diastolik daerah trikuspid
36. Atrial Septal Defect
Auscultation :1st HS N or loud
widely split and fixed 2nd HS
Ejection Sistolic Murmur
55. Tetralogy Fallot
• Diagnosis Differential
Pulmonary Atresia
Double outlet right ventricle and pulmonary stenosis
Transposisi of great arteri and pulmonary stenosis
57. Tetralogy of Fallot
< 1 yr > 1 yr
spell (+) spell (-)
propranolol
failed cath
succeed
BTS
small PA good sized PA
total correction
• clinically
• ECG
• CXR
• echo
age 1 yr
cath BTS/
PDA Stent
evaluation
