Segmental analysis in congenital heart diseases

1. Segmental analysis of the Heart
By
Dr.M.Gibreel, FEBR, FAHC
Cardiac imaging senior Registrar
AHC & NHI

2. Segmental Approach
Analysis/ Evaluation of the heart in terms of segments in a step-by-step
fashion based on pattern of recognition of “normal”. Relation of the
segments to each other.
It facilitates communication between physicians from various
subspecialties who are involved in diagnosis and management of CHD.
The segments are the atria, ventricles, and great arteries
Visceroatrial situs, the ventricular loop, and the conotruncus.
The only fixed landmark is: right and left of the patient.

4. House Layout
• 3 floors (Major Segments)
– Viscero-atrial situs
– Ventricular loop
– Conotruncus
Or, more simply:
– Atria
– Ventricles
– Great Arteries
• 2 staircases (Segmental Connections)
– AV junction
– Conus or Infundibulum
• 2 Entrances
– Systemic veins
– Pulmonary Veins

5. Schools of segmental analysis
Richard Van Praagh Rob Anderson

6. • It was first described by Van Praagh nearly 50 years ago, in which a three-
part notation “{S, D, S}” is used as follows:
The 1st letter ….> The viscero-atrial situs
The 2nd letter ….> The ventricular looping
The 3rd letter …> The position and relation of the great vessels.

7. Terminology of Congenital Heart Disease
• Position.
• Situs.
• Looping.
• Concordance .

8. Cardiac Position = -cardia , relation of apex to
base
• Levocardia (left-sided).
• Dextrocardia (right-sided).
• Mesocardia (centrally located) within the thorax.
• Ectopia cordis (partially or completely outside the thorax).

9. Situs
• Situs = arrangement
• Possibilities :
1)Solitus = usual /normal . LA to the left , RA to the right.
2) Inversus = mirror the solitus . LA to the right , RA to the left.
3) ambiguus= Vague either right or left isomerism Heterotaxy
Syndromes
Hetero = “different”; -taxy = “arrangement”

10. Situs
• Body Segments: Atrial, Tracheo-bronchial, and Abdominal

11. Atrial situs “{X, , }”
•The atrial situs can usually be
established from visceral situs. In the
correct and reversed order.
•It is very rare for atrial solitus not to
reflect the visceral situs .

12. RA
• Appendage (triangular & wide base) + IVC.
• Crista terminalis >> ridge dividing between the
smooth part of the right atrium and the right
atrial appendage

13. RA

14. LA
• Appendage (long & narrow), trabeculations
• Rhomboid

15. LA

18. Atrial situs

19. Atrial morphology, arrangement and relation to each other
2 morphologically different
atriums, left atrium is to left side
and right atrium to the right side .
2 morphologically different
atriums, left atrium is to right side
and right atrium to the left side .
2 morphologically similar atriums,
2 left atria
2 right atria .

21. Thoraco-abdominal
situs “{X, , }”

23. Abdominal Situs

24. Tracheo-bronchial situs

26. Tracheo-bronchial situs

30. Left or right isomerism?
Left Right
IVC Interrupted continuous
CS LSVC to CS Absent CS
PV Normal to ipslateral TAPVD
IAS ASD I Common atrium
SVC Bilateral ++ Bilateral

32. Ventricular loop / Looping
• Defined by the rotation of the right ventricle (D-loop when the RV
seen to the right).
D-loop: RV right-sided relative to LV
L-loop: RV left-sided (levo or L) relative to LV.

33. RV
RV
D-loop L-loop

34. Ventricle
• The normal ventricle possess 3 components:
• Inlet component: the portion downstream of AV valve annlus = inflow
• Trabecualr component: body of the ventricle distal to the insertion of the
papillary muscle
• Outlet (infundibular)component : portion that supports the arterial valve of
the ventricle= outflow tract or conus.
• Continuity of inlet &outlet.

35. • LV in DORV is accepted to a ventricle though it has no
outlet competent.
• The minimal requirement for chamber to be considered a
ventricle are that it possess an inlet and trabecular
competent.
• Chambers which do not have an inlet portion are not
ventricles and are described as rudimentary chambers.
• Rudimentary chambers are 2 types :
 Outlet chambers , if it supplies great vessel
 Trabecular pouches, if no great vessel supplied by it .

37. Ventricular identification
RV
• Pyramidal shape.
• Moderator band.
• Trabeculated septal surface
• TV septal leaflet is more apical i.e. more toward the apex.
(TV predilection to septum & reverse to semilunar V.)
• Coarse trabeculations .

39. LV
• Oval shape
• Fine trabeculations
• Smooth septal surface, Papillary muscle.
• (Mitral V predilection to semilunar V i.e. A-M continuity , and the
reverse to the septum).

41. LV

43. LA
RA

45. RV
RV
D-loop L-loop

48. Version
• Dextroversion= situs solitus + dextrocardia.
• Levoversion = situs inversus + levocardia.

51. AV connections

53. STRADDLING
• A feature of the tensor apparatus (chordae tendineae and papillary
muscles) of an AV valve and indicates anomalous insertion into the
contralateral. ventricle, either along its septum or its free wall

54. Potential AV connections
AOPA
RV
LV
RA
Concordant Discordant; cc-TGA CAVC
RV
LV
RA
LA

55. Potential AV connections
Tricuspid atresia DILVMitral atresia
RV
LA
LV
RA
RV
LA
LV
RA
LA
LVRA

56. Great vessels……No isomersum
• Aorta: Arch and neck vessles , giving coronaries
• Pulmonary artery: usually bifurcates

57. Normal
Inversus

61. VA connection,,, VentriculoArterial Connection
• If Ao from LV and PA from RV: Concordant
• If Ao from RV and PA from LV: Discordant
• 3rd type of VA connection: Double outlet, almost always from RV.
• Final type of VA connection: Single outlet (truncus arteriosus).

63. Loop Rule
Assumption used if determination of morphologic ventricles is difficult:
• In presence of a right-sided aortic valve, the RV is to the right of the
LV (D-loop).
• In presence of a left-sided aortic valve, the RV is to the left of the LV
(L-loop).

64. D-TGA L-TGA
Ao PA
RV LV
AO
PA
LV
RV
Potential ventriculo-arterial connections

65. Potential ventriculo-arterial connections
DORV Truncus
arteriosus
Ao PA
RV
LV
PA
AO
RV

66. Infundibulum (conus)
• The infundibulum is part
from the RV and acts as the
connecting segment between
the ventricle and great
vessels:
• Sub-pulmonic “normal”,
• Sub-aortic “mostly in TGA”,
• Double conus “mostly in
DORV”,
• Absent conus, least common
“mostly in DOLV”.
Courtesy of Tal Geva, MD

67. RV
AO
RV
Ao
PA

71. Associated anomalies
 Venous connection
 IAS
 IVS
 Valves
 Myocardium
 Coronary anatomy
 Peripheral pulmonary arteries
 Aortic arch

77. Thank you