ECHO : SEGMENTAL APPROACH

Dr Binjo J VazhappillySR CardiologyMCH Calicut

Segmental Approach to Imaging Congenital Heart Disease (CHD)

• Systematic and sequential method to describe the cardiac segments and connections.

• Three cardiac segments : atria , ventricle and great vessels.

• Connections : specific relationship between the segments .

Determine visceroatrial situs • Situs refers to spatial arrangement of the viscerae .

Three types of visceroatrial situs • S – solitus (normal arrangement) • I – inversus (or the mirror-image arrangement) • A - ambiguus

• Situs ambiguus : defined as an abnormality in which thoracic and abdominal organs are positioned with respect to each other, in such a way that it cannot be clearly lateralized.

Situs Solitus

Situs Inversus

Right Isomerism(Asplenia)

Left Isomerism (polysplenia)

Cardiac Position & Orientation

• Position of the heart in the chest with regard to its location and orientation of its apex.

Location of heart in the chest• Levoposition : to the left • Mesoposition : central• Dextroposition : to the right

Cardiac orientation is the base to apex orientation of heart• Levocardia : apex directed to left of midline.• Mesocardia : apex oriented inferiorly in the midline• Dextrocardia: apex directed to right of midline.

Atrial Morphology

Right Atrium • Triangular, broad based,

anterior appendage .• Receives IVC, SVC & coronary

sinus.• Septum secundum (limbus of

fossa ovale) lies on RA side.

• Crista Terminalis is in RA.

Left Atrium• Narrow, fingerlike posterior

appendage . • LA receives all 4 pulmonary

veins • Septum primum lies on LA

side . • LA is smooth with fewer

trabeculations

The right & left atria are identified morphologically by their respective atrial appendages and veins emptying into them.

Atrial Morphology

Pulmonary veins to LA

Atrial Situs

• Atrial Situs Solitus (S)

• Atrial Situs Inversus (I)

• Atrial Situs Ambiguous (A)

Right isomerism (bilateral right atria) or Left isomerism (bilateral left atria).

Ventricular Looping

• Embryonic heart is a linear tube with bulbus cordis (future RV ) being cephalad to the developing left ventricle (LV) .

• In normal development the tube bends over on itself to right forming a D-loop resulting in positioning of the bulbus cordis to the anatomic right of the left ventricle

• Folding to left results in L-loop with the morphologic right ventricle being to the left of the morphologic left ventricle

Ventricular Looping

D Loop L Loop

Identification of the ventricles

Tricuspid Valve RV⇒

• Septal chordal attachments• Apical septal annular

attachment• 3 leaflet • Multiple small papillary

muscles• Triangular orifice

Mitral valve LV⇒

• No septal chordal attachments

• Basal septal annular attachments

• 2 leaflet• 2 large papillary muscles• Elliptical orifice.

AV valve morphology directly correlates with ventricular type

RV Morphology

• Large apical trabaculations

• Coarse septal surface

• Moderator bands

• Cresentic in cross section

• Tricuspid – pulmonary discontinuity

LV Morphology

• Small apical trabeculations

• Smooth upper surface

• No moderator band

• Mitral – Aortic continuity

Atrio-ventricular Connections

• Concordant ( Normal : RA to RV & LA to LV)

• Discordant ( RA to LV & LA to RV)

• Univentricular AV connections Absent AV connection Common AV valve Double inlet connections

Concordant AV Connection

Univentricular AV Connections

• Absent AV connection (right / left) Tricuspid / mitral atresia

• Common AV valve With single ventricle

• Double inlet ventricle Connection of both AV valve to the same ventricle Anatomically left Anatomically right Undetermined (rudimentary chamber always present)

Univentricular AV connections

Univentricular AV connections

Absent Rt AV Connection Absent Lt AV connection

Univentricular AV connections

Double inlet : RV Morphology Double inlet : LV Morphology

Overriding & Straddling

• Overriding : Biventricular emptying of AV Valve or biventricular origin of a

semilunar valve.

• Straddling : Chordae or papillary muscle of the valve attach to contralateral

ventricle. Involve AV Valves and requires presence of VSD.

Arterial Morphology

• Aorta : artery that gives rise to the coronary arteries and the brachiocephalic vessels.

• Pulmonary artery : branches into two but does not give rise to any vessels.

Ventriculo-Arterial Connection

• Concordant : Aorta connected to LV and pulmonary artery to RV .• Discordant :

Aorta connected to RV and pulmonary artery to LV .

• Double Outlet : Both great arteries arise from a single ventricle. • If more than 50% of an artery overrides a ventricle it is said to be

committed to it.

Commitment

• Commitment describes possible abnormalities of flow through valves into ventricles and great vessels.

• In TOF, atria, AV valves & ventricles are positioned normally and concordant.

Aorta overrides a VSD and is doubly committed to both ventricles.

• In univentricular heart both AV valves are usually doubly committed to the single ventricle.

Ventriculo-arterial connections

• Concordant (normal) Ventricular septal defect, tetralogy of Fallot• Discordant Transposition• Double outlet ventricle With subaortic VSD subpulmonary VSD doubly committed VSD non-committed VSD• Common arterial trunk

Conus

• Subpulmonary: Absence of subaortic infundibular free wall, found in normal heart.• Subaortic: Absence of subpulmonary infundibular free wall, found in D-loop

TGA.• Bilaterally present : In double outlet RV , but rarely in TGA.• Bilaterally Absent: In double outlet LV.

Relation b/w semilunar Valves

• Solitus : Aorta posterior and to right.

• Inversus : mirror image : Aorta posterior and to left

• D-malposition : aortic valve anterior and to the right.

• L-malposition : aortic valve anterior and to the left.

• Anterior malposition : aortic valve anterior in the middle.

• Parasternal and high parasternal short axis and subcostal short axis views are used to recognize the positions of AV and PV.

Possible Great vessel relations

Normal

PSX Suprasternal long and short axis

d TGA

cc TGA

DORV

TOF

Truncus Arteriosus

Assessment of Associated Anomalies

Abnormalities in each segment should be assessed

Septal defects AV valve abnormalities like Ebstein’s Outflow tract stenosis Aortic arch branching and sidedness Pulmonary artery and branches PDA Coronary abnormalities

Ebstein anomaly

Pulmonary valve pathology

LV outflow

Subaortic membrane Supravalvular AS

COARCTATION OF AORTA

Sequential Segmental Approach

• Identify situs of the thoraco-abdominal organs.• Determine cardiac position within thorax.• Atrial Situs.• Ventricular Situs.• Atrioventricular connection and alignment.• Ventriculo-arterial connection and alignment.• Conal (infundibular) anatomy.• Relationship between the great arteries.• Description of associated malformations

Segmental Expression

1 . Visceroatrial situs : S , I or A.2 . Ventricular situs : D or L3 . Position of great vessels : S , I , D , L or A

Normal : S , D , S Situs inversus Dextrocardia : I , L , I D TGA : S , D , D D TGA with situs inversus : I , L ,L L TGA with situs solitus : S , L , L

QUIZ

1. Interrupted IVC is seen in

A) Situs inversusB) Situs solitusC) Right isomerism D) Left isomerism

2. Morphological feature of right atrium

A) Finger like posterior appendageB) Smooth surfaceC) Presence of cristae terminalisD) Septum primum lies on RA side

3. True about right atrial appendage

A) Narrow basedB) TriangularC) PosteriorD) None of the above

4.True about ventricular morphology

A) LV is cresentic in cross sectionB) Moderator band is seen in RVC) Trabaculations are less in RVD) RV has smooth septal surface

5. Straddling means

A) Papillary muscle of the valve attached to contralateral ventricle.

B) Papillary muscle attached to septumC) Absence of papillary muscleD) Fusion of papillary muscle

6. In d TGA true about connection is

A) AV discordant , VA concordantB) AV concordant , VA discordantC) Both AV and VA concordantD) Both AV and VA discordant

7. In TOF true about connection is

A) AV discordant , VA concordantB) AV concordant , VA discordantC) Both AV and VA concordantD) Both AV and VA discordant

8. Conus is bilaterally absent in

A)DORVB) TGAC) DOLVD) Normal heart

9. In d malposition of great arteries

A) Aorta posterior and to rightB) Aorta posterior and to leftC) Aorta anterior and to rightD) Aorta anterior and to left

10.Segmental expression of L TGA is

A) S , D , SB) I , L , IC) S, D , D D) S , L , L

1. Interrupted IVC is seen in

A) Situs inversusB) Situs solitusC) Right isomerism D) Left isomerism

2. Morphological feature of right atrium

A) Finger like posterior appendageB) Smooth surfaceC) Presence of cristae terminalisD) Septum primum lies on RA side

3. True about right atrial appendage

A) Narrow basedB) TriangularC) PosteriorD) None of the above

4. True about ventricular morphology

A) LV is cresentic in cross sectionB) Moderator band is seen in RVC) Trabaculations are less in RVD) RV has smooth septal surface

5. Straddling means

A) Papillary muscle of the valve attached to contralateral ventricle.

B) Papillary muscle attached to septumC) Absence of papillary muscleD) Fusion of papillary muscle

6. In d TGA true about connection is

A) AV discordant , VA concordantB) AV concordant , VA discordantC) Both AV and VA concordantD) Both AV and VA discordant

7. In TOF true about connection is

A) AV discordant , VA concordantB) AV concordant , VA discordantC) Both AV and VA concordantD) Both AV and VA discordant

8. Conus is bilaterally absent in

A)DORVB) TGAC) DOLVD) Normal heart

9. In d malposition of great arteries

A) Aorta posterior and to rightB) Aorta posterior and to leftC) Aorta anterior and to rightD) Aorta anterior and to left

10.Segmental expression of L TGA is

A) S , D , SB) I , L , IC) S, D , D D) S , L , L

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