Segmental approach to Congenital Heart Disease: From Developmental Anatomy to Pathology

1. SEGMENTAL APPROACH TO
CONGENITAL HEART DISEASE
FROM DEVELOPMENTAL ANATOMY TO PATHOLOGY
TANATTABTIEANG, MD
ADVISOR:Assist. Prof. MONRAVEE TUMKOSIT, MD RADIOLOGIST
Division of Diagnostic Radiology, Department of Radiology
Faculty of Medicine, Chulalongkorn University
King Chulalongkorn Memorial Hospital (KCMH)

2. CONTENTS
 Van Praagh Classification System
 Related Embryology
 Step 1: Visceroatrial situs
 Step 2: Ventricular Loop Orientation
 Step 3: Position and Relation of the GreatVessels
 Assessment of Connecting Segments
 Example Cases from KCMH
 Summary

3. VAN PRAAGH CLASSIFICATION SYSTEM
 “Segmental” approach to the heart
 Developed and implemented in 1960s in Boston, MA
 Most widely used in the imaging workup of
congenital heart disease in North America
 Facilitating communication in diagnosis,
characterization and management
 Three part notation
 Three-part series of letter
 Corresponding to key segment of embryologic region
of cardiac anatomy
BostonChildren’sHospital

4. VAN PRAAGH CLASSIFICATION SYSTEM
 “Sequential” segmental analysis
 Developed by Anderson and colleague in 1970s
 Emphasizing how the chamber are connected and related
 Atrioventricular (A-V) junction
 Ventriculoarterial (V-A) junction
{ _ , _ , _ }
Visceroatrial situs Ventricular loop
orientation
Position and relation
of the Great vessels

5. Step 1
Visceroatrial situs
Step 2
Ventricular loop
orientation
Step 3
Position and relation
of the Great vessels
Segments:
Connections: Atrioventricular
junction
Ventriculoarterial
junction
Put it all together

6. RELATED EMBRYOLOGY
 Primodial (primitive) heart tube
 Initially straight
 Atrial portion receive venous blood from left &
right sinus venosus
 Sinus venosus receives the umbilical, vitelline, and
common cardinal veins from the chorion,
umbilical vesicle, and embryo, respectively
Truncus arteriosus
Bulbus cordis
Single ventricle
Primitive atrium
Sinus venosus
NeillC,2006

7. RELATED EMBRYOLOGY
 Normal looping (D-loop)
 Begins to loop inside pericardial sac at
approximately 23 to 28 days of gestation
(bulboventricular loop)
 The primitive heart tube grows, loops anteriorly
and to the right
 Cephalic end of heart tube bends ventrally,
caudally, and slightly rightward
 Bulbus cordis located to the right of LV, result in
RV on the right
 Heart rotate in to left thorax, heart apex pointing
to the left
TA (future great vessels)
BC (future RV)
Ventricle (future LV)
Primitive atrium
MooreKL,2016
NeillC,2006

8. RELATED EMBRYOLOGY
 Partitioning of truncus arteriosus
 Aorticopulmonary septum formation during
5th week
 When partitioning of the truncus arteriosus
is nearly completed, the semilunar valves
begin to develop around the orifices of the
aorta and pulmonary trunk.
MooreKL,2016

9. Posterior
Anterior
LeftRight
Moore KL, 2016

10. RELATED EMBRYOLOGY
 Development of cardiac valves
 Muscle under aortic valve is resorbed
 Atrioventricular (mitroaortic) fibrous continuity
 Subpulmonary muscle (conus) grows
 Pulmonary valve locates farther from AV valves
without fibrous continuity
 After resorption of muscle, aortic valve lies
posterior and rightward of the
pulmonary valve
 Semilunar valves undergo 150° counterclockwise
rotation
 Aorta connect to LV and the main PA connect
to RV
Posterior
Anterior
~150°
Neill C, 2006

11. Netter FH, 2014

12. Atrioventricular (mitroaortic) fibrous continuity
Netter FH, 2014

13. Anterior
Posterior
RightLeft
Aortic valve lies posterior and rightward of the pulmonary valve
Netter FH, 2014

14. RELATED EMBRYOLOGY
 Development of venous structures
 At 4th week, three pairs of venous system drain into
the primordial heart
 Posterior cardinal veins drain caudal parts of the
embryo
 Subcardinal and supracardinal veins gradually develop
and replace and supplement the posterior cardinal
veins
MooreKL,2016

15. RELATED EMBRYOLOGY
 Development of venous structures
 Above the kidney, they are united and
becomes azygos and hemiazygos
veins
 Below the kidneys, the left supracardinal
vein degenerates, but right supracardinal
vein becomes the inferior part of the
IVC
MooreKL,2016

16. RELATED EMBRYOLOGY
 The IVC is composed of four main segments
 A hepatic segment derived from the hepatic vein
(proximal part of the right vitelline vein) and
hepatic sinusoids
 A prerenal segment derived from the right
subcardinal vein
 A renal segment derived from the subcardinal–
supracardinal anastomosis
 A postrenal segment derived from the right
supracardinal vein
MooreKL,2016

17. TERMINOLOGY
 In congenital heart approach
 A structure named as “right” or “left” because it normally be found on the right or left
side, e.g., right ventricle or left ventricle
 Regardless of whether it is actually on which side of the patient
 E.g., if the patient left atrium is on the right side, it would still be called the left atrium because of
its characteristic structure
 The word morphologic is used to indicate that the internal characteristic structure
is meant, without implication about the actual location of the structure

18. TERMINOLOGY
 Position of the heart in thorax and orientation of cardiac apex are contributive
to but not determinative of the situs
 Help predict the incidence of congenital heart disease
 Cardiac position
 The position of the greater mass of the heart with respect to the sternum
 Levoposition : mainly in the left chest
 Mesoposition : midline positon of the heart
 Dextroposition : mainly in the right chest
 Cardiac base-apex axis may be oriented normally
 May caused by extrinsic factor, e.g., hypoplasia or agenesis of lung

19. TERMINOLOGY
 Cardiac orientation
 When the cardiac axis has the same directional orientation as greater mass of the
heart
 Levocardia
 Mesocardia
 Dextrocardia
MazurW,2013

20. Dextrocardia: an abnormal cardiac position at the right of
the sternum, combined with an abnormal rightward orientation
of the cardiac axis.
Dextroposition: an abnormal cardiac position at the right
of the sternum, combined with a normal leftward
orientation of the cardiac axis, secondary to right lung
hypoplasia due to right pulmonary vein atresia.
RadioGraphics 2013; 33:E33–E46

21. STEP 1
VISCEROATRIAL SITUS
{ X , _ , _ }

22. VISCEROATRIAL SITUS
 Relationship between the atria and the adjacent organs
 Three type of situs
 Situs solitus { S , _ , _ }
 Situs inversus { I , _ , _ }
 Situs ambiguus { A , _ , _ }
{ X , _ , _ }Visceroatrial Situs

23. 1. Visceral situs
 Determining whether liver, stomach and spleen located on patient’s right or left side
2. Thoracoabdominal situs
 Determining structure of bronchopulmonary anatomy
3. Morphologic RA
 Identify the morphologic RA
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
VISCEROATRIAL DESIGNATION
{ X , _ , _ }Visceroatrial Situs

24. Determining whether liver, stomach and spleen located on patient’s right or left side
 S
 Largest lobe of the liver on the RIGHT
 Spleen and stomach on the LEFT
 I
 Largest lobe of the liver on the LEFT
 Spleen and stomach on the RIGHT
 A
 Not fit either category
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
VISCERAL SITUS
{ X , _ , _ }Visceroatrial Situs

25. Largest hepatic lobe on right side, spleen and
stomach on the left side, normal configuration
Left-sided liver, right-sided stomach and multiple
right-sided splenic tissue
RadioGraphics 2013; 33:E33–E46

26. Useful for identifying the morphologic RA
Pulmonary sideness usually reflects atrial sideness
 S
 Morphologic (trilobed) right lung and largest lobe of liver on the RIGHT
 I
 Morphologic (bilobed) right lung and largest lobe of liver on the LEFT
 A
 Duplicate sideness or not fit either category
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
THORACOABDOMINAL SITUS
{ X , _ , _ }Visceroatrial Situs

27. Morphologic right lung
 Trilobe
 Presence of minor fissure
 Main bronchus is above behind the
PA (eparterial)
 Upper lobe bronchus more proximal
originate
Morphologic left lung
 Bilobe
 Absent of minor fissure
 Main bronchus is below the PA
(hyparterial)
 Upper lobe bronchus more distal
take off
THORACOABDOMINAL SITUS
{ X , _ , _ }Visceroatrial Situs

28. Netter FH, 2014

29. The characteristic early takeoff of the right upper
lobe bronchus.
The morphologic right atrium is usually found on the
same side as the morphologic right bronchial tree.
Normal central bronchial anatomy which can be used
to help differentiate the morphologic right lung from
the morphologic left lung.The right main stem
bronchus (asterisk) is more vertically oriented with
an early branch point (white arrow)
RadioGraphics 2013; 33:E33–E46 Mazur W, 2013

30. Duplication of the morphologic left bronchial tree pattern, with no early takeoff of the upper lobe bronchus on the right side,
and a hyparterial position of both main bronchi below the course of the main pulmonary arteries
These findings are indicative of left isomerism, a setting in which the bronchial anatomy is unhelpful for determining right- or
left-sideness of the morphologic right atrium.
RadioGraphics 2013; 33:E33–E46

31. Identify the morphologic RA
 S
 Morphologic RA on the RIGHT
 I
 Morphologic RA on the LEFT
 A
 Cannot be determined
 Atrial situs and thoracoabdominal situs usually concordant
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
ATRIAL SITUS
{ X , _ , _ }Visceroatrial Situs

32. ATRIAL SITUS
Morphologic RA
 Right atrial appendage is broad and blunt, trapezoidal shape
 Pectinate muscles extend around the vestibule and reach
toward AV valve
 Crista terminalis and tenia sagittalis
 Septal surface consists of superior and inferior limbic bands
 Receive blood from supradiaphragmatic IVC (rule of
venoatrial concordance)
 Coronary sinus drains into RA via Thebesian valve
{ X , _ , _ }Visceroatrial Situs
Neill C, 2006

33. ATRIAL SITUS
Morphologic LA
 Right atrial appendage is narrower, tubular, finger-like shape
 Pectinate muscles not beyond the appendage
 Receive blood from pulmonary veins
{ X , _ , _ }Visceroatrial Situs
Neill C, 2006

34. ATRIAL SITUS
{ X , _ , _ }Visceroatrial Situs
RadioGraphics 2013; 33:E33–E46

35. Normal anatomy of the left atrium and right atrium.
The right atrial appendage (RAA) typically has a triangular shape,
with a wider opening and larger pectinate muscles (arrows) than
those of the left atrial appendage (LAA), which has a fingerlike
shape.
RadioGraphics 2007; 27:829–846
The right atrial appendage (RAA) is triangular with a wide opening,
whereas the left atrial appendage (LAA) is narrow and fingerlike.
RadioGraphics 2003; 23:S147–S165

36. Trapezoidal shape of the right atrial appendage with
its blunt end and broad connection to the rest of
the atrium
Tubular left atrial appendage with its pointed end
and narrow connection.
RadioGraphics 2013; 33:E33–E46

37.  If any letter recorded as A situs ambiguus { A , _ , _ }
 If ALL the letters recorded as S situs solitus { S , _ , _ }
 If ALL the letters recorded as I situs inversus { I , _ , _ }
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
VISCEROATRIAL DESIGNATION
{ X , _ , _ }Visceroatrial Situs

38. SITUS SOLITUS
{ S , _ , _ }
 Morphologic RA and liver on the RIGHT side
 Morphologic LA, stomach and spleen on the LEFT
side
 Morphologic (trilobed) right lung with eparterial
bronchus on the RIGHT side
 Morphologic (bilobed) left lung with hyparterial
bronchus on the LEFT side
{ X , _ , _ }Visceroatrial Situs
RadioGraphics 2010; 30:397–411

39. SITUS INVERSUS
{ I , _ , _ }
 Morphologic RA and liver on the LEFT side
 Morphologic LA, stomach and spleen on the RIGHT
side
 Morphologic (trilobed) right lung with eparterial
bronchus on the LEFT side
 Morphologic (bilobed) left lung with hyparterial
bronchus on the RIGHT side
{ X , _ , _ }Visceroatrial Situs
RadioGraphics 2010; 30:397–411

40. SITUS AMBIGUUS (HETEROTAXY SYNDROME)
{ A , _ , _ }
 Heterotaxy syndrome
 With asplenia / Right isomerism / Bilateral right-sideness
 With polysplenia / Left isomerism / Bilateral left-sideness
{ X , _ , _ }Visceroatrial Situs
RadioGraphics 2010; 30:397–411
Right isomerism Left isomerism

41. With Polysplenia
 Left isomerism
 Bilateral bilobed lung, hyparterial
bronchus with absent minor fissure
 Bilateral morphologic LA
 Interruption of IVC with azygos or
hemiazygos continuation
 Multiple spleens
 Pulmonary veins drains into both RA
and LA
With Asplenia
 Right isomerism
 Bilateral trilobed lung, eparterial
bronchus and bilateral minor fissures
 Bilateral morphologic RA
 Large symmetric, centrally located
liver
 Absent spleens
 Frequent total anomaly of
pulmonary venous return (TAPVR)
SITUS AMBIGUUS (HETEROTAXY SYNDROME)
{ X , _ , _ }Visceroatrial Situs
RadioGraphics 2010; 30:397–411

42. With Polysplenia With Asplenia
SITUS AMBIGUUS (HETEROTAXY SYNDROME)
{ X , _ , _ }Visceroatrial Situs
An interrupted suprarenal IVC with azygous or hemiazygous
continuation. The abdominal aorta and IVC are classically located
on opposite sides of the midline
The ipsilateral position of the abdominal aorta and IVC
RadioGraphics1999;19:837–852

43. RELATION OF CARDIAC POSITION TO CHD
 Situs solitus with levocardia (normal)
 CHD occurs 0.6-0.8%
 Situs inversus with dextrocardia
 CHD occurs 3-5%
 Situs inversus with levocardia
 Extremely rare variant
 CHD occurs 100%
 Situs ambiguous or heterotaxy
 Highly incidence associated CHD
 Discordant position of one or more of cardiac apex, stomach, and aortic arch position
 Associated with extra-cardiac anomalies
e.g, splenic abnormalities, biliary atresia, and intestinal malrotation
{ X , _ , _ }Visceroatrial Situs

44. RadioGraphics 2010; 30:397–411

45. STEP 2
VENTRICULAR LOOP ORIENTATION
{ _ , X , _ }

46. VENTRICULAR LOOP DESIGNATION
 Relation of morphologic RV as compared
with the morphologic LV
 Morphologic RV on RIGHT of morphologic LV:
Dextro-loop { _ , D , _ }
 Morphologic RV on LEFT of morphologic LV:
Levo-loop { _ , L , _ }
 If cannot be determined: { _ , X , _ }
{ _ , X , _ }
Ventricular Loop Orientation
D-loop { _ , D , _ }
Normal
L-loop { _ , L , _ }
Neill C, 2006

47. VENTRICULAR INTRINSIC CHARACTERISTICS
Morphologic RV
 Coarse trabeculae
 Presence of apical moderator band
 Papillary muscles attached to both the interventricular
septum and the free wall
 Tricuspid AV valve
 Separation of inlet (tricuspid) and outlet (pulmonary) valves
by muscular ridge (crista supraventricularis)
 Saddle-shaped
{ _ , X , _ }
Ventricular Loop Orientation
Neill C, 2006

48. Morphologic right ventricle (RV), which is characterized by
coarse trabeculae and a muscular crest, the crista
supraventricularis (arrowhead), between the tricuspid valve
(TV) and the pulmonary valve (PV).
RadioGraphics 2007; 27:829–846
A muscular structure (arrowheads) between the tricuspid valve (TV) and
the pulmonary valve (PV).The right ventricle shows coarse trabeculae.
RadioGraphics 2003; 23:S147–S165

49. Moderator band (arrow) traversing the apex of a cardiac chamber and extending from the base of the papillary muscle to
the septal wall, helps identify the morphologic right ventricle.
RadioGraphics 2013; 33:E33–E46

50. VENTRICULAR INTRINSIC CHARACTERISTICS
Morphologic LV
 Thin and delicate trabeculae
 Smooth septal surface
 Papillary muscles attached only to the free wall
 Bicuspid AV valve
 Complete continuity of fibrous tissue between inlet (mitral)
and outlet (aortic) valves (mitroaortic fibrous continuity)
{ _ , X , _ }
Ventricular Loop Orientation
Neill C, 2006

51. Left ventricular inflow and outflow tract shows normal
anatomy of the morphologic left ventricle with fine
trabeculae, the anterolateral and posteromedial papillary
muscles, and fibrous continuity (arrowhead) between the
aortic valve (AV) and the mitral valve (MV).
RadioGraphics 2007; 27:829–846 RadioGraphics 2003; 23:S147–S165
Fibrous continuity (arrowhead) between the mitral valve (MV) and the
aortic valve (AV).The left ventricle shows fine trabeculae.

52. A moderator band (arrowhead) and a papillary muscle (arrow) attached to the interventricular septum, findings characteristic
of the morphologic RV. Because this chamber is positioned leftward of the left ventricle, a position indicative of an L-loop, the
letter L is assigned, thus “{_, L, _}.”
LV
RV
RadioGraphics 2013; 33:E33–E46

53. A papillary muscle (arrow) attached to the septal wall, a feature that helps identify this chamber as the RV. Because the
chamber is positioned rightward of the left ventricle, a position indicative of d-loop, the letter D is assigned, thus {_, D, _}”
LV
RV
RadioGraphics 2013; 33:E33–E46

54. RV
RV
RV
RV
LV
LV
LV
LV
RadioGraphics 2010; 30:397–411

55. RadioGraphics 2013; 33:E33–E46

56. HAND RULE AND LOOP RULE
 In complicated case that orientation may be difficult to discern because spiral
configuration does not fit right-left plane easily
 E.g. superoinferior ventricles, crisscross AV alignments, single ventricle
 Hand rule
 Loop rule
{ _ , X , _ }
Ventricular Loop Orientation

57. HAND RULE
 Identify the RV
 Imagine approach the heart from anterior
direction
 Placing your hand inside the RV with palm against
interventricular septum, the thumb in RVIT (AV
valve) and fingers in RVOT
 Accomplish with Right hand
>> Rightward orientation, D-loop { _ , D , _ }
 Accomplish with Left hand
>> Leftward orientation, L-loop { _ , L , _ }
{ _ , X , _ }
Ventricular Loop Orientation
D-loop
{ _ , D , _ }
Normal
L-loop
{ _ , L , _ }

58. While viewing the heart from the anterior to the posterior direction, the viewer imagines placing a hand into the morphologic
right ventricle with the palm against the interventricular septum, the thumb in the RVIT, and the fingers in the RVOT. If this
exercise can be performed with the right hand, a d-loop is present; if it can be performed only with the left hand, an l-loop is
present.
RVIT
RVOT
Septum
RadioGraphics 2013; 33:E33–E46

59. LOOP RULE
 Position and relation of great vessles are
predictive of the loop orientation
 Right-sided aortic valve
 RV located rightward of LV
>> D-loop { _ , D , _ }
 Left-sided aortic valve
 RV located leftward of LV
>> L-loop { _ , L , _ }
{ _ , X , _ }
Ventricular Loop Orientation
CT scan shows the aortic valve with right (R), left (L), and
noncoronary (N) cusps and the pulmonary valve with right (R),
left (L), and anterior (A) cusps.
Pulmonary
Aortic
RadioGraphics 2003; 23:S147–S165

60. STEP 3
POSITION AND RELATION OF THE GREATVESSELS
{ _ , _ , X }

61. RELATION OF THE GREATVESSELS
 Aorta and main PA are classified according to
their position at the level of aortic and
pulmonary valves
 Aorta supplies at least one coronary artery
 Main PA usually yields right and left PA
 Normal configuration:Aortic lies posterior and
rightward of the PA
 Conus anatomy may be helpful
{ _ , _ , X }
Position and Relation of the GreatVessels
Posterior
Anterior
~150°
Neill C, 2006

62. Normal configuration of the great vessels.The aorta (A) has a
normal posterior relation and normal rightward position relative to
the MPA (P), a configuration designated as {_, _, S}
CT scan shows the aortic valve with right (R), left (L), and
noncoronary (N) cusps and the pulmonary valve with right (R), left (L),
and anterior (A) cusps.
Pulmonary
Aortic
RadioGraphics 2013; 33:E33–E46 RadioGraphics 2003; 23:S147–S165

63. DESIGNATION
 Aorta is posterior to and rightward of main PA (normal)
>> situs solitus { _ , _ , S }
 Aorta is posterior to but inverted leftward of main PA
>> situs inversus { _ , _ , I }
 Transposition: usually applies when aorta arises from
the RV and main PA arises from LV
 Aorta is anterior to and rightward of main PA
>> D-transposition { _ , _ , D-TGV }
 Aorta is anterior to and leftward of main PA
>> L-transposition { _ , _ , L-TGV }
{ _ , _ , X }
Position and Relation of the GreatVessels
RadioGraphics 2013; 33:E33–E46

64. Inversion of the great vessels. Situs inversus of the great vessels at the level of the valves.The aorta has a normal posterior
relation to the MPA but is positioned at its left, a mirror image of the normal configuration, designated as {_, _, I}.
RadioGraphics 2013; 33:E33–E46

65. DESIGNATION
 Malposition: both arteries originate from same ventricles or are overriding e.g. in
double-outlet left or right ventricle (DORV or DOLV)
 Aorta is rightward of main PA >> D-malposition { _ , _ , D-MGV }
 Aorta is leftward of main PA >> D-malposition { _ , _ , L-MGV }
{ _ , _ , X }
Position and Relation of the GreatVessels
RadioGraphics 2013; 33:E33–E46

66. RadioGraphics 2010; 30:397–411

67. CONOTRUNCAL ANOMALIES
 During development, muscle under aortic valve resorbed, whereas subpulmonary
muscle (conus) grows
 Conal anatomy
 Subpulmonary conus (normal)
 Subaortic conus
 Bilateral conus
 Bilaterally absent conus
 Presence of conus under semilunar valve usually indicates that vessel originate
from RV (exception may occurred)
{ _ , _ , X }
Position and Relation of the GreatVessels

68. CONOTRUNCAL ANOMALIES
 Double outlet cardiomyopathies: the great vessels are side-by-side (MGV)
 Bilateral conus is seen in double-outlet RV (DORV) without atrioventricular fibrous
continuity
 Bilaterally absent conus is seen in double-outlet LV (DOLV) with atrioventricular fibrous
continuity
{ _ , _ , X }
Position and Relation of the GreatVessels

69. CONOTRUNCAL ANOMALIES
 Subaortic conus without subpulmonary conus is found in case of D- or L-TGV
 Aorta which lack atrioventricular (mitroaortic) fibrous continuity is anterior to the
pulmonary valve with atrioventricular valve continuity
 Transposition usually applies when aorta arises from RV and main pulmonary
artery arises from LV
{ _ , _ , X }
Position and Relation of the GreatVessels

70. CONOTRUNCAL ANOMALIES
 D-transposition { S , D , D-TGV }
 Complete (uncorrected) TGA
 Normal position of atrium and ventricle, A-V concordance,
anomaly only at the conus level
 Right-sided aorta anteriorly positioned arises from RV
with subaortic conus
 Left-sided PA posteriorly positioned arises from LV
with mitropulmonary fibrous continuity
{ _ , _ , X }
Position and Relation of the GreatVessels
Ao
RV
LV
PA
MazurW,2013
Right
Atrium
Right
Ventricle
Aorta
Left
Atrium
Left
Ventricle
Pulmonary
artery

71. CONOTRUNCAL ANOMALIES
 L-transposition { S , L , L-TGV }
 Congenitally (physiologically) corrected transposition
 Abnormal positioning of great vessels and inverted
ventricular position (L-loop)
 Associated with A-V discordance
{ _ , _ , X }
Position and Relation of the GreatVessels
Ao
LV
RV
PA
MazurW,2013

72.  L-transposition { S , L , L-TGV }
 Left-sided RV connected to LA and anteriorly left-sided aorta
(with subaortic conus)
 Right-sided LV connected to RA and right-sided PA (with
mitropulmonary fibrous continuity)
Ao
LV
RV
PA
MazurW,2013
Right
Atrium
Left
Ventricle
Pulmonary
artery
Left
Atrium
Right
Ventricle
Aorta
Atrioventricular
discordance
Ventriculoarterial
discordance
CONOTRUNCAL ANOMALIES
{ _ , _ , X }
Position and Relation of the GreatVessels

73. ASSESSMENT OF CONNECTING
SEGMENTS

74. Step 1
Visceroatrial situs
Step 2
Ventricular loop
orientation
Step 3
Position and relation
of the Great vessels
Segments:
Connections: Atrioventricular
junction
Ventriculoarterial
junction
Put it all together

75. ATRIOVENTRICULAR (A-V) CONNECTIONS
5 types of atrioventricular connection
1. Concordant
 Ventricle appropriate relative to visceroatrial situs
 Morphologic RA drains into morphologic RV,
morphologic LA drains into morphologic LV
2. Discordant
 Ventricle inappropriate relative to visceroatrial situs
 Morphologic RA drains into morphologic LV,
morphologic LA drains into morphologic RV
 E.g., transposition of great vessels
Connecting Segments
Concordant Discordant
MazurW,2013

76. ATRIOVENTRICULAR (A-V) CONNECTIONS
3. Ambiguous
 Visceroatrial situs ambiguus
 Heterotaxy
Connecting Segments
MazurW,2013

77. ATRIOVENTRICULAR (A-V) CONNECTIONS
4. Double inlet
 Single ventricle
5. Absent right or left
connection
 Dominant left or right
ventricle
Connecting Segments
Right-
sided
atrium
Left-
sided
atrium
Right-
sided
atrium
Left-
sided
atrium
Right-
sided
atrium
Left-
sided
atrium
Double inletAbsent right connection Absent left connection
MazurW,2013

78. VENTRICULOARTERIAL (V-A) CONNECTION
Connecting Segments
4 types of atrioventricular connection
1. Concordant
 Main PA arises from morphologic RV, aorta arises from morphologic LV
2. Discordant
 Main PA arises from morphologic LV, aorta arises from morphologic RV
 Synonymous with transposition of the great vessels
Ao
RV
LV
PA
Ao
RV
LV
PA Ao
LV
RV
PA
MazurW,2013

79. VENTRICULOARTERIAL (V-A) CONNECTION
Connecting Segments
3. Double-outlet right ventricle (DORV)
 The great vessels arise from RV
4. Double-outlet left ventricle (DOLV)
 The great vessels arise from LV
MazurW,2013

80. ASSOCIATED MALFORMATIONS
 Importance for surgical approach and profound physiologic significance
 Heart
 Atrial and ventricular septal defects
 Size of ventricles
 Ventricular outflow tract stenosis
 Great vessels
 Hypoplastic or stenotic lesion
 PDA
 Coronary anomalies
 SVC

81. EXAMPLE CASES
FROM KCMH

82. CASE I
 Step 1: Determine visceroatrial situs
 Largest lobe of the liver on the RIGHT
 Spleen and stomach on the LEFT
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
Record letter S
KCMH

83. CASE I
 Step 1: Determine visceroatrial situs Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
KCMH
Eparterial
bronchus
Right Left
Hyparterial
bronchus
PA PA

84. CASE I
 Step 1: Determine visceroatrial situs
 Morphologic (trilobed) right lung and
largest lobe of liver on the RIGHT
Record letter S
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
KCMH

85. CASE I
 Step 1: Determine visceroatrial situs
Record letter S
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
Trapezoid-shape,
broad and blunt
with a wider
opening
Fingerlike and
narrowRAA
LAA
KCMH

86. CASE I
 If ALL the letters recorded as S situs solitus { S , _ , _ }
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
S S S
{ S , _ , _ }

87. CASE I
 Step 2: Determine ventricular loop orientation
Papillary
muscle
Coarse
trabeculation
Thin
trabeculation
LV RV
LV RV
 Morphologic RV on LEFT of morphologic LV: Levo-loop { _ , L , _ }
{ S , L , _ }
KCMH

88. CASE I
 Step 3: Position and Relation of the GreatVessels
Aorta is anterior to and leftward
of main PA
L-transposition { _ , _ , L-TGV }
{ S , L , L-TGV }
Pulmonary
Aortic
KCMH

89. CASE I
 Determine connecting segments
{ S , L , L-TGV }
Right
Atrium
Left
Ventricle
Pulmonary
artery
Left
Atrium
Right
Ventricle
Aorta
Atrioventricular
discordance
Ventriculoarterial
discordance
Ao
LV
RV
PA
MazurW,2013

90. CASE I
 Associated anomalies
 Membranous ventricular septal aneurysm
 Patent foramen ovale
 Pulmonary hypertension
{ S , L , L-TGV }
Ventricular
septal aneurysm
Patent foramen
ovale
KCMH

91. CASE I
 Findings:
 Situs solitus with levocardia
 Levo-transposition of the great vessels
 Atrio-ventricular and ventriculo-arterial discordance
 Diagnosis: Congenitally corrected L-TGA
{ S , L , L-TGV }
Ao
LV
RV
PA
MazurW,2013

92. CASE 2
 Step 1: Determine visceroatrial situs
 Largest lobe of the liver on the LEFT
 Spleen and stomach on the RIGHT
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
Record letter L
KCMH

93. CASE 2
 Step 1: Determine visceroatrial situs
 Bilateral morphologic bilobed lungs
Bilateral hyparterial bronchus
 Situs ambiguus with LEFT isomerism
(polysplenia)
Record letter A
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
KCMH
PA PA

94. CASE 2
 Step 1: Determine visceroatrial situs
Record letter A
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
 One large dilated single
common atrium
 Broad based atrial appendage on
right side
Broad and blunt,
trapezoidal
shape
KCMH

95. CASE 2
 If any letter recorded as A situs ambiguus { A , _ , _ }
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
S A A
{ A , _ , _ }

96. CASE 2
 Step 2: Determine ventricular loop orientation
Coarse
trabeculation
 Single ventricle with coarse trabeculation and moderator band >> morphologic RV
 Right-sided aortic valve (Loop Rule) >> Dextro-loop { _ , D , _ }
{ A , D , _ }
Subpulmonic
conus
KCMH
Pulmonary
Aortic

97. PulmonaryAortic
CASE 2
 Step 3: Position and Relation of the GreatVessels
 The great vessels are along the same
coronal plane, but aorta is rightward
of main PA
>> Dextro-malposition
{ _ , _ , D-MGV }
 Aorta and pulmonary trunk arises
from single ventricle
 Malposition: both arteries originate
from same ventricles
{ A , L , D-MGV }
KCMH

98. CASE 2
 Determine connecting segments
{ A , L , D-MGV }
Common
Right Atrium
Single Right
Ventricle
Pulmonary
artery
Aorta
The great vessels arise from RV
DORV
Absent Left
connection
Common A-V valve

99. CASE 2
 Associated anomalies
 Left-sided SVC
 Interrupted IVC with azygos
continuation
 Dilated hemiazygos and azygos drains into left-
sided SVC
{ A , L , D-MGV }
Absent
intrahepatic IVC
Dilated
hemiazygos v
Left-sided
SVC
Dilated
hemiazygos v
KCMH

100. CASE 2
 Associated anomalies
 Left-sided SVC and pulmonary veins
draining into common atrium
 Hepatic veins draining into common
atrium
{ A , L , D-MGV }
KCMH

101. CASE 2
 Diagnosis:
 Situs ambiguus with left isomerism
 Dilated common atrium, hypertrophic single RV
 Common atrioventricular canal
 Double outlet RV (DORV)
 Left-sided SVC, and interrupted IVC with azygos continuation
{ A , L , D-MGV }

102. SUMMARY OF
SEGMENTAL APPROACH

103. Determining whether liver, stomach and spleen located on patient’s right or left side
 S
 Largest lobe of the liver on the RIGHT
 Spleen and stomach on the LEFT
 I
 Largest lobe of the liver on the LEFT
 Spleen and stomach on the RIGHT
 A
 Not fit either category
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
VISCERAL SITUS
{ X , _ , _ }Step 1:Visceroatrial Situs
Record letter

104. Useful for identifying the morphologic RA
Pulmonary sideness usually reflects atrial sideness
 S
 Morphologic (trilobed) right lung and largest lobe of liver on the RIGHT
 I
 Morphologic (bilobed) right lung and largest lobe of liver on the LEFT
 A
 Duplicate sideness or not fit either category
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
THORACOABDOMINAL SITUS
{ X , _ , _ }Step 1:Visceroatrial Situs
Record letter

105. Morphologic right lung
 Trilobe
 Presence of minor fissure
 Main bronchus is above behind the
PA (eparterial)
 Upper lobe bronchus more proximal
originate
Morphologic left lung
 Bilobe
 Absent of minor fissure
 Main bronchus is below the PA
(hyparterial)
 Upper lobe bronchus more distal
take off
THORACOABDOMINAL SITUS
{ X , _ , _ }Step 1:Visceroatrial Situs

106. Identify the morphologic RA
 S
 Morphologic RA on the RIGHT
 I
 Morphologic RA on the LEFT
 A
 Cannot be determined
 Atrial situs and thoracoabdominal situs usually
concordant
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
ATRIAL SITUS
{ X , _ , _ }Step 1:Visceroatrial Situs
Record letter

107. ATRIAL SITUS
{ X , _ , _ }Step 1:Visceroatrial Situs
RadioGraphics 2013; 33:E33–E46

108.  If any letter recorded as A situs ambiguus { A , _ , _ }
 If ALL the letters recorded as S situs solitus { S , _ , _ }
 If ALL the letters recorded as I situs inversus { I , _ , _ }
Visceral Situs
Thoraco-
abdominal
Situs
Atrial Situs
VISCEROATRIAL DESIGNATION
{ X , _ , _ }Step 1:Visceroatrial Situs

109. VENTRICULAR LOOP DESIGNATION
Determine which ventricle is the morphologic RV and which is the morphologic LV
 Morphologic RV on RIGHT of morphologic LV: { _ , D , _ } Dextro-loop
 Morphologic RV on LEFT of morphologic LV: { _ , L , _ } Levo-loop
 If cannot be determined: { _ , X , _ }
 Hand rules
 Loop rules
{ _ , X , _ }
Step 2:Ventricular Loop Orientation

110. RadioGraphics 2013; 33:E33–E46

111. DESIGNATION
Determine the position and relation of the aorta and the main PA at the level of the
aortic and pulmonary valves
 Aorta is posterior to and rightward of main PA situs solitus { _ , _ , S }
 Aorta is posterior to and leftward of main PA situs inversus { _ , _ , I }
 Aorta is anterior to and rightward of main PA D-transposition { _ , _ , D-TGV }
 Aorta is anterior to and leftward of main PA L-transposition { _ , _ , L-TGV }
{ _ , _ , X }
Step 3: Position and Relation of the GreatVessels
RadioGraphics 2013; 33:E33–E46

112. DESIGNATION
 The great vessels are along the same coronal plane, but
 Aorta is rightward of main PA Dextro-malposition { _ , _ , D-MGV }
 Aorta is leftward of main PA Levo-malposition { _ , _ , L-MGV }
{ _ , _ , X }
Step 3: Position and Relation of the GreatVessels
RadioGraphics 2013; 33:E33–E46

113. RadioGraphics 2013; 33:E33–E46

114. ATRIOVENTRICULAR CONNECTIONS
5 types of atrioventricular connection
1. Concordant
 Ventricle appropriate relative to
visceroatrial situs
 Morphologic RA drains into morphologic
RV,
morphologic LA drains into morphologic
LV
2. Discordant
 Ventricle inappropriate relative to
visceroatrial situs
 Morphologic RA drains into morphologic
LV,
morphologic LA drains into morphologic
RV
 E.g., transposition of great vessels
3. Ambiguous
 Visceroatrial situs ambiguus
 Heterotaxy
4. Double inlet
 Single ventricle
5. Absent right or left connection
 Dominant left or right ventricle
Connecting Segments

115. VENTRICULOARTERIAL CONNECTION
Connecting Segments
4 types of atrioventricular connection
1. Concordant
 Main PA arises from morphologic RV, aorta arises from morphologic LV
2. Discordant
 Main PA arises from morphologic LV, aorta arises from morphologic RV
 Synonymous with transposition of the great vessels
3. Double-outlet right ventricle (DORV)
 The great vessels arise from RV
4. Double-outlet left ventricle (DOLV)
 The great vessels arise from LV

116. MazurW,2013

117. REFERENCES
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852. doi:10.1148/radiographics.19.4.g99jl31837
 Fulcher AS,Turner MA.Abdominal Manifestations of Situs Anomalies in Adults. RadioGraphics. 2002;
22:1439–1456.doi:10.1148/rg.226025016
 Goo HW, et al. CT of Congenital Heart Disease: Normal Anatomy andTypical Pathologic Conditions.
RadioGraphics.2003; 23:S147–S165.doi:10.1148/rg.23si035501
 Leschka S, et al. Pre- and Postoperative Evaluation of Congenital Heart Disease in Children and Adults
with 64-Section CT. RadioGraphics 2007; 27:829–846. doi:10.1148/rg.273065713
 Lapierre C, et al. Segmental Approach to Imaging of Congenital Heart Disease. RadioGraphics. 2010;
30:397–411. doi:10.1148/rg.302095112
 Schallert EK, et al. Describing Congenital Heart Disease by UsingThree-Part Segmental Notation.
RadioGraphics.2013; 33:E33–E46. doi:10.1148/rg.332125086
 Neill C, et al.The Segmental Approach to Congenital Heart Disease. In: Nichols DG, editors. Critical
Heart Disease in Infants and Children. 2nd ed. Philadelphia: Mosby Elsevier; 2006.
 MazurW, et al. CT Atlas of Adult Congenital Heart Disease. London: Springer-Verlag, 2013.
 Moore KL, et al. Cardiovascular System. In: Moore KL, PersaudTVN,Torchia MG.The Developing
Human. 10th ed. Philadelphia: Elsevier; 2016.