Download Fetal Echocardiography

Fetal Echocardiography
Dr. Durr-e-Sabih
Multan, Pakistan
[email protected]
http://www.geocities.com/dsabih
Why
• Commoner than most realize
• 1% in all live births
• Approximately 5% in all pregnancies
•The incidence increases if there is a
positive family history
•if sibling affected incidence is 2 – 4%
•if mother affected incidence is 10-12%
Indications
• Family history
• Exposure to known cardiac teratogens
• Chromosomal
abnormalities (trisomy 21,
50%; trisomy 13 and 18, almost 100%)
• Maternal
disease (diabetes, collagen disease,
phenylketonuria, infections)
• Non-cardiac abnormalities detected on US
• Polyhydramnios
Cardiac embryology
Weeks Length Event`
mm
1-2
1.5
No heart or great vessel
4
2
Single median cardiac tube, ineffective
contraction
5
4
Bilobed atrium
5
4
Begining of circulation
5
7.5
AV orifices, 3 chamber heart
6
8.5-13 Septum secundum, complete inferior
septum, divided truncus arteriosus,
7
20
4 chamber heart
Cardiac Size
20 week fetus’
heart compared
with an
American
quarter
Usual HR
120-160/min
Time
• The best time to do a fetal cardiac exam is
18-22 weeks
• Later exams may show anatomy better but
might be difficult because of rib shadowing
• Adequate exam depends on fetal position
and maternal habitus
• Some pathologies become obvious with
fetal age
Fetal Circulation
Fetal circulation is
complex and different
from adult blood flows
with three major shunts:
Ductus venosus
Forman ovale
Ductus arterosus
Rate and rhythm
•The heart rate is usually 120-160/min,
the rhythm is regular but transient
bradycardia is normal in the 2nd
trimester but not in the 3rd
First assess fetal
position
Acquire a four chamber view
• Transverse section through the fetal thorax
• Corresponds to the 4 chamber apical view
in the adult
• The atrium nearest the spine is the left
atrium
• The atrium nearest the fetal anterior
thoracic wall is the right
Axis
• 45+20 towards the left
• Abnormal axis increases the risk of a
cardiac malformation
• The heart may also be displaced from its
o
normal position in dipaphragmatic hernia or
cystic adenomatoid malformation
•Fetus cephalic
•Probe marker to mother’s left
•Fetal spine posterior
• Fetus breech
• Probe marker normal
• Fetal spine posterior
Basic fetal cardiac examination
General
•Done on a 4 chamber view
•Heart mostly in left chest
•Occupies 1/3 of thoracic area
•Normal cardiac situs, axis and
position
•No pericardial effusion
rd
Basic fetal cardiac examination
Atria
•Both of same size
•Foramen ovale flap in
left atrium
•lower end of atrial septum
(septum primum) present
Atria
•Lower end of septum
•Foramen ovale
•Flap of foramen ovale
in LA
Basic fetal cardiac examination
Ventricles
•Equal size
•Intact septum
•Moderator band
identifies right ventricle
Ventricles
• Both of same size
• Moderator band
identifies right
ventricle
Basic fetal cardiac examination
AV Valves
•Both valves move freely
•Tricuspid valve inserted
more apically than mitral
Extended basic cardiac
examination
• The outflow tracts are imaged by tilting
the probe towards the fetal head
• The great vessels should be of equal size
and should cross at approximately 90o as
they emerge from their respective ventricles
Look for these:
•The outflow tracts cross each other at about 90
•The anterior aortic root wall is continuous with the
o
Inter Ventricular Septum
•The pulmonary artery bifurcates
•The aortic and pulmonary valves move freely
•Both great vessels are of similar size but the
pulmonary artery tends to be slightly bigger
The aortic arch
• The aortic arch can
be identified
• The aortic cusps can
be seen
The pulmonary artery bifurcates
The outflow tracts cross at
around 90o
Pulm trunk
Aortic arch
Cases
Echogenic Intracardiac Focus
(EIF)
• Can be seen in up to 6%
of normal pregnancies
• Highly operator and
machine dependant
• Associated with cardiac
and extracardiac anomalies
• Bilateral EIF is more
significant
EIF
Biventricular EIF are more significant
this patient was 47XY
Normal nuchal translucency