- An ultrasound scan of the fetal heart at 19 weeks' gestation revealed a ventricular septal defect on the four-chamber view, with right to left flow seen on Doppler. - While VSD was initially suspected, further evaluation of the left ventricular outflow tract was needed as VSD can be associated with other conditions like transposition of the great arteries or tetralogy of Fallot. - Examination of the left ventricular outflow tract showed the VSD leading into a great vessel that straddled the interventricular septum, confirming the diagnosis of tetralogy of Fallot. Additional views beyond the four-chamber view are needed to identify associated cardiovascular anomalies when a VSD is present.

2. •Structural cardiac anomalies are estimated to occur
in 8 of 1,000 live births
•Cardiovascular anomalies are frequently associated
with other congenital anomalies because the heart
begins to develop the 3rd week after conception
and continues to develop until the end of the 8th
week.

3. •Since most cardiac abnormalities are
found in patients without associated risk
factors, evaluation of the fetal heart is an
important component of a routine
obstetric ultrasonographic examination.

4. •ISUOG guidelines suggest that the fetal
cardiac examination be performed between
18-22 weeks.
•Under exceptional conditions, it can be
performed earlier, especially if First Trimester
Screening shows an abnormality or increased
Nuchal Translucency

5. • Firstly, a ‘basic’ scan should be performed by analyzing a
four-chamber view of the fetal heart.
• Secondly, an ‘extended-basic’ scan further examines the
size and relationships of both arterial outflow tracts.
• The term ‘fetal echocardiogram’ was also mentioned as a
more detailed sonographic evaluation to be performed
by specialists in the prenatal diagnosis of CHD.

6. •Maternal indication
•Fetal indication

7. •A fetal echocardiogram should be performed
if recognized risk factors raise the likelihood
of congenital heart disease beyond what
would be expected for a low-risk screening
population.

9. •High frequency probe to be used
•Harmonic imaging may aid in better image quality
•Gray scale is the basis for examination
•Narrow image field, high frame rate
•Image should be zoomed till it occupies 1/3 to 1/ 2
of the display screen

10. Before any abnormalities can be
described, the proper technique of
fetal heart ultrasound examination
should be discuses

11. •First know the orientation of the fetus:
•Presentation and lie of the fetus
•Supine or prone position
•The spine becomes the point of reference in
determining fetal orientation.

12. R R

13. WHAT CONSTITUTES A FATAL CARDIAC EXAMINATION
•Basic Screening-4 chamber
view
•Extended Basic Screening-4
chamber view + outflow
tracts
•Fetal Echocardiography

15. BASIC SCREENING
FOUR CHAMBER VIEW

16. BASIC SCREENING FOUR CHAMBER VIEW
•A part of routine mid trimester
scan
• Any one who is doing it should
be doing it should At LEAST do
a basic screening
• Preferably extended screening

17. BASIC SCREENING FOUR CHAMBER VIEW
•Easy to obtain
•Move up from AC view
•Easy to identify
•Easy to standardize
•Can be easily included in
mid trimester scan
protocol without incurring
additional expense/ time.

20. AXIS OF THE HEART

21. AXIS OF THE HEART
•Situs abnormalities should be suspected when
the fetal heart and/or stomach is/are not
found on the left side as well.
•Abnormal axis increases the risk of a cardiac
malformation, especially involving the outflow
tracts.

22. POSITION OF THE HEART

23. POSITION OF THE HEART
•Abnormal cardiac position can be caused by a
diaphragmatic hernia or space-occupying lesion,
such as cystic adenomatoid malformation.
•Position abnormalities can also be secondary to
fetal lung hypoplasia or agenesis.

24. •Size
•Pericardial effusion
•2 Atria roughly equal
•2 Ventricles roughly
equal

25. • Two distinct atrioventricular valves (right-sided, tricuspid
and left-sided, mitral) should be seen to open separately
and freely.
• The septal leaflet of the tricuspid valve is inserted to the
septum closer to the apex when compared to the mitral
valve (i.e. normal offset).
• Abnormal alignment of the atrioventricular valves can be
a key sonographic finding for cardiac anomalies such as
atrioventricular septal defect

26. HEART RATE
• Cardiac rate and regular rhythm should be confirmed.
• The normal rate ranges from 120 to 160 beats per minute.
• Mild bradycardia is transiently observed in normal second-
trimester fetuses.
• Fixed bradycardia, especially heart rates that remain below 110
beats per minute, requires timely evaluation for possible heart
block.
• Repetitive heart rate decelerations during the third trimester can
be caused by fetal distress.
• Persistent tachycardia, however, should be further evaluated for
possible fetal distress or more serious tachydysrhythmias.

28. SUMMARY

29. • Two-thirds of the
heart in left
hemithorax.

30. • Apex on the left, with
45° ± 20° cardiac axis
(levocardia).

31. • At least two
pulmonary veins
draining in the left
atrium.

32. • Two atria of similar
size.

33. • Foramen ovale flap
opening into the left
atrium, with evidence
of the septum
premium.

34. • Presence of the crux of
the heart, with offset
aspect of the two
atrioventricular valves,
which show normal
systo-diastolic
excursion.

35. • Two ventricles of
similar diameter, with
mild prevalence of the
right one, which also
shows a rounder
appearance because
of the presence of the
moderator band. The
left ventricle forms the
cardiac apex.

36. • Equal thickness of the
free ventricular walls,
with normal
contractility.

37. • Intact interventricular
septum.
In addition, the
rhythm and rate
should be checked.

38. SUMMARY

39. • Normal heart.

40. • Right atriomegaly
from tricuspid
dysplasia
and insufficiency.

41. • Ebstein’s anomaly,
with apical
displacement of the
insertion of the
tricuspid valve.

42. • Ventricular septal defect.

43. • Atrioventricular septal
defect (with common
atrioventricular valve).

44. • Left ventricular
hypoplasia and
mitral atresia
(hypoplastic left
heart syndrome).

45. • Right ventricular
hypoplasia (plus
ventricular septal
defect) due to
tricuspid atresia

46. • Double-inlet
single ventricle.

47. • Ventricular
disproportion
and moderate
prevalence of
the right
ventricle (an
indirect sign of
aortic
coarctation).

48. • Biventricular
hypertrophy
(cardiomyopathy).

49. • Tumors
(rhabdomyomatosis).

50. IS 4 CHAMBER VIEW A
GOOD SCREENING TEST ?

51. LIMITATIONS OF 4 CHAMBERS VIEW
•Only 40% of CHD can be diagnosed with 4
Chamber view
• Various studies quote a range from 15-60%

52. LIMITATIONS OF 4 CHAMBERS VIEW
• WHY 4 CH VIEW FAILS?
• CHD NOT ASSOCIATED WITH ABNORMAL 4 CH VIEW
• 1. Abnormalities of great vessels not associated with
any defect on cardiac chambers
• 2. CHDs with progressive evolution
• 3. CHDs not detectable in utero

53. LIMITATIONS OF 4 CHAMBERS VIEW
(1) ABNORMALITIES OF GREAT VESSELSNOT ASSOCIATED WITH
EFFECT ON CHAMBERS:
• Mild Aortic stenosis,
• Tetralogy of Fallot
• Coarctation of aorta
• Pulmonary stenosis
• Transposition of great vessels
• Double outlet ventricle
• Truncus Arteriosus
• Pulmonary atresia with VSD

54. LIMITATIONS OF 4 CHAMBERS VIEW
(2) CHDS WITH PROGRESSIVE EVOLUTION
•Pulmonary stenosis
•Aortic Coarctation
•Ventricular hypoplasia

55. LIMITATIONS OF 4 CHAMBERS VIEW
(3) CHDS NOT DETECTABLE INUTERO
•Isolated ASD
•(Postnatally) Patent ductus arteriosus
•Small VSD
•Partial anomalous pulmonary venous
•(Postnatally) Patent connection foramen ovale

56. EXTENDED BASIC
SCREENING
4 chamber view + Outflow
tract

58. • LVOT-LEFT VENTRICULAR OUTFLOWTRACT

59. •Originates entirely from LV
•Septo Aortic continuity
•Free movement of the valves
•No post valvular dilatation
•No regurgitation on color Doppler

60. •LVOT is truly the aorta, it should even be
possible to trace the vessel into its arch
•The LVOT view may help to identify
ventricular septal defects and conotruncal
abnormalities that are not seen during the
basic cardiac examination alone.

62. •Originates entirely from RV
•It is anterior and to the left of aorta
•Free movement of valves
•Bifurcates in two after the origin
•Aorta is seen as a ring
•No regurgitation on Doppler

63. Differentialdiagnosisofleftoutflow
tractanomalies
Out flow obstruction
Cross over anomalies
transposition of the great
arteries
double-outlet right
ventricle
Anomalies of septo-aoratic continuity Right out flow tract assessment

64. • transposition of the great arteries, if each vessel is connected with the contralateral
ventricle ( left ventricle-pulmonary artery and right ventricle -aorta;

65. • double-outlet right ventricle, if both great vessels are connected with the right
(anterior) ventricle.

66. • Hypoplastic Left Heart Syndrome
• Endocardial Cushion Defect
• Ventricular Septal Defect
• Persistent Truncus Arteriosus
• Complete Transposition of the Great Arteries
• Double-Outlet Right Ventricle
• Tetralogy of Fallot

67. • Hypoplastic left heart syndrome is a
spectrum of heart malformations
that consists of a small left ventricle,
which is associated with aortic atresia
and an atretic or hypoplastic mitral
valve.
• Represents 2%–4% of congenital
heart defects

68. • In making the diagnosis,
the four-chamber view is
usually sufficient to,
demonstrate the
abnormalities
• Base view may be helpful
in documenting the
disproportionately smaller
aorta in comparison to
the pulmonary artery

69. • When the endocardial cushions fail to
fuse, a wide range of atrioventricular
septal defects occur.
• The complete form of endocardial
cushion defect consists of a large defect
involving the inferior portion of the atrial
septum and the posterior portion of the
ventricular septum

70. •An endocardial cushion
defect can be accurately
diagnosed by using only the
four-chamber view

71. • one of the most common cardiac
anomalies, accounting for 20%–40% of
congenital heart defects
• A normal interventricular septum
extends from the cardiac apex to the
atrial septum
• Formation of the interventricular
septum begins at approximately 28
days gestation when the median
muscular ridge begins to invaginate.

72. • The muscular septum fuses with the membranous septum
formed by the endocardial cushions at approximately 49
days gestation
• A ventricular septal defect (VSD) results from
maldevelopment of the embryonic muscular septum,
maldevelopment of the endocardial cushions, or excess
resorption of myocardial tissue in the muscular septum

73. • A large VSD is easily diagnosed
on the four-chamber view
alone.
• However, color Doppler US may
be needed to demonstrate
smaller defect
• Some may not be detected
until after birth.

74. • Persistent truncus arteriosus accounts for
approximately 1%–2% of congenital heart
defects
• It is characterized by a single overriding
arterial trunk that feeds both the aorta
and the pulmonary artery.
• The undivided truncus receives blood
from both ventricles.
• A VSD is almost always present

75. • This diagnosis may not be
apparent on the four-
chamber view alone.
• However, several attempts at
obtaining a base view will fail
to reveal normal crossing of
the great vessels.
• Instead, a single vessel is seen
with several branches
connecting with the
pulmonary vessels and aorta

76. •Represents 2.5%–5% of
congenital heart defects
•This occurs by the caudal and
spiral growth of the conal truncal
ridge, which is usually complete
by the end of the 4th week after
conception

77. • Only when the aorta is seen to
arise definitely from the right
ventricle and the pulmonary
artery is seen to arise definitely
from the left ventricle can one
be confident of the diagnosis.
• The base view of the fetal heart
is needed to confirm the
diagnosis by demonstrating
that the great vessels do not
cross

78. • Tetralogy of Fallot is caused by unequal division
of the conus resulting from anterior
displacement of the truncoconal system.
• Tetralogy of Fallot has four classic features: a
VSD, an overriding aorta, pulmonary artery
stenosis, and right ventricular hypertrophy.
Owing to the shunts that exist in the fetal
circulation, the right ventricular hypertrophy may
not be seen in utero.
• Represents approximately 3%–7% of congenital
heart defects

79. • The diagnosis of tetralogy of Fallot is
suspected when a large VSD leads
into a great vessel that straddles the
interventricular septum.
• The pulmonary artery may not be
easily demonstrated, since the
predominant feature of the anomaly
is usually the overriding aorta. Again,
the main reason for suspecting this
anomaly is failure to demonstrate the
normal crossing of the great vessels
at the base of the heart

81. HISTORY: A PATIENT UNDERGOES A ROUTINE
ULTRASOUND SCAN AT 19 WEEKS’ GESTATION.
L L

82. • Gray scale and Doppler image Four chamber
view of fetal heart show a defect in proximal
part of VSD with right to left flow seen in
Doppler images. Normal axis, position……..
• Dx: VSD
•IS THIS ENOUGH??!!
•NO..
• VSD ASSOCIATED WITH .
• Transposition of the great arteries
Tetralogy of Fallot
Truncus arteriosus
• OTHER VIEW IS ESSENTIAL

83. • Gray scale of left out flow
view show fetal heart
show a defect in proximal
part of VSD, the
malalignment ventricular
septal defect leads into a
great vessel that straddles
the interventricular
septum
•Dx: Tetralogy of
Fallot