Segmental Approach to the Diagnosis of Congenital Heart Disease

Segmental Approach to the
Diagnosis of Congenital Heart
Disease
Lyna El-Khoury Rumbarger, B.S. RDCS
UMBC DMSP
Program Chair
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Echo Views for Congenital Heart Disease
• Subcostal approach: Situs and Cardiac Position , AO and IVC to
spine position. Identify IAS
and the relationships
of IAS and IVS
to the atrioventricular
valves. Image
Pulmonary Veins
LVOT, RVOT,AV, AO,
PV, MPA and branches
IVC, SVC and IAS.
• Apical 4C, 5C, 2C and 3C
• PLAX and PSAX, all levels
• Suprasternal views :
great vessels, ductus
arteriosus , aortic arch and
AO to PA relationship. 2
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Adults with CHD
• The number of adults with known congenital heart
disease (CHD) has increased dramatically over the past
few decades because of significant advances in cardiac
imaging, diagnosis and medical and surgical care.
• For the past 10 years, the number of adults with
congenital cardiovascular malformations has equaled the
number of children with these disorders. The majority of
children born with CHD are surviving into adulthood.
• With additional improvements in surgical techniques and
with repairs occurring at an earlier age, this patient
group is likely to increase even further.
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Adult CHD Centers
• Infants born with complex CHD are not always cured.
• Residual problems are common and predictable.
• There are many challenges in the transition of care from
pediatric to adult practitioners.
• Adults with moderate and complex CHD should undergo
regular evaluation at a regional ACHD center.
• In order to properly care for these patients, we must
have detailed knowledge of CHD, both repaired and
unrepaired.
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Indications for Echo in Adults with CHD
1. Patients with suspected CHD due to clinical
signs and symptoms such as murmurs, cyanosis
or unexplained arterial desaturation, abnormal
ECG or chest X-Ray.
2. Patients with known CHD on follow-up due to
change in clinical findings.
3. Patients with known CHD for whom there is
uncertainty as to the original diagnosis,
structural abnormalities and hemodynamics.
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Indications for Echo in Adults with CHD
4. Patients with known, repaired or unrepaired
CHD for whom ventricular function, valve
regurgitation, residual shunts and/or pulmonary
artery pressure must be followed.
5. Patients undergoing Echo guided interventional
catheter procedures: valvotomy, ablation, septal
defect closure…
6. Follow-up Echo exams annually or once every 2
years, in patients with known CHD without
evident change in clinical condition.
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Segmental Approach to Anatomy
• The initial echo exam of the patient with
suspected CHD requires a sequential and
systematic approach to cardiac anatomy.
• This approach is based on following the blood
flow into the heart (systemic venous and
pulmonary venous), through the heart (atria,
atrioventricular valves and ventricles) and then
out of the heart (through semilunar valves and
great vessels).
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Segmental Approach to the
Diagnosis of CHD
• The first step is to determine the atrial situs and
assess the connecting veins and their inflow
pattern into the atria.
• Then the ventricular arrangement, morphology
and position are determined and the
atrioventricular connections are defined.
• Finally the arrangement of the great arteries is
determined and their connections to the
ventricles (ventriculoarterial relationships).
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Sequential Segmental Approach
• Identify the situs of the thoraco-abdominal organs.
• Determine cardiac position within the thorax.
• Segment by segment analysis of cardiac anatomy.
• 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.
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Viscero-Abdominal Situs
• First examine the abdominal viscera: positions of
liver, stomach, spleen, and abdominal great
vessels (AO/IVC).
1. Situs solitus: Aorta lies to the left of the spine
and the IVC to the right.
2. Situs inversus: Aorta lies to the right of the
spine and the IVC to the left.
3. Right isomerism: both vessels lie on the same
side with the Aorta posterior.
4. Left isomerism: both vessels lie on the same
side with the Aorta anterior.
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Abdominal Situs Solitus
A
R
L
Liver
IVC
AO
Spine
P
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Thoraco-Abdominal Situs
• Situs Solitus: normal arrangement, left stomach,
left spleen, right liver, right lung with 3 lobes,
left lung with 2 lobes.
• Situs Inversus: inverted arrangement, right
stomach, right spleen, left liver, right lung with 2
lobes, left lung with 3 lobes.
• Right Isomerism: Asplenia (no spleen), bilateral
right-sidedness, both lungs have 3 lobes.
• Left Isomerism: Polysplenia (multiple spleens),
bilateral left-sidedness, both lungs have 2 lobes,
often interrupted IVC.
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Situs Solitus
• This is the normal
arrangement in most
patients with the
organs on their
appropriate sides.
• Atrial Situs Solitus
also seen.
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Situs Inversus
• This is sometimes
know as a mirror
image arrangement.
• Atrial Situs Inversus is
also seen.
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Right Isomerism: Asplenia
• Known as asplenic syndrome.
The lungs are both tri-lobed
(right morphology) with short
main bronchi. The atria are
both of right sided
morphology. 2 SA nodes may
occur. Cardiac problems
include anomalous pulmonary
venous return, septation &
abnormal cardiac position.
Infections are a serious risk
as the spleen is absent.
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Left Isomerism: Polysplenia
• Known as polysplenic syndrome.
The lungs are both bi-lobed (left
morphology) with long main
bronchi. The atria are both of
left sided morphology. No true
SA node exists. Cardiac
problems include anomalies of
systemic venous return,
septation & abnormal cardiac
position. The IVC is incomplete
& continues as the azygous and
hemiazygos veins. The liver is
usually central and polysplenia is
common.
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Slightly Central Liver
with Polysplenia
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Bronchial Tree
• In Situs Solitus, the right
main bronchus is shorter
than the left and takes off
at a more acute angle
from the trachea.
• The reverse is true in
situs inversus.
• There are two
symmetrical short main
bronchi in right isomerism
and two longer bronchi in
left isomerism.
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Cardiac Position & Orientation
• Position of the heart in the chest with regard to its
location, and the orientation of its apex.
• Location of the heart in the chest:
1. Levoposition - to the left
2. Mesoposition - central
3. Dextroposition - to the right
• Cardiac orientation is the base to apex orientation of the
heart:
1. Levocardia - apex directed to the left of the midline
2. Mesocardia - apex oriented inferiorly in the midline
3. Dextrocardia - apex directed to the right of the midline
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Imaging Patients with
Cardiac Malposition
• When confronted with a patient with known (or suspected)
cardiac malposition, begin scanning from the subcostal
transverse imaging plane. The transducer index mark and
image (screen) index mark should both be oriented to the
patient's left.
• Define relative positions of AO, IVC, and spine.
• Sweep and tilt up to demonstrate the position of the heart
in the chest and the direction the apex is pointing.
• Continue tilting anteriorly to determine the atrioventricular
and ventriculoarterial connections and positions of the
great vessels.
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Dextrocardia
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Imaging Patients with Dextrocardia
• Patients with Dextrocardia should be positioned in the
right lateral decubitus position, and the sonographer
should be positioned such that scanning can be
comfortably performed with the patient in that position.
• Imaging patients with Dextrocardia should include a
clear illustration of an empty left chest. The orientation
of the transducer over the right chest should be the
same as it usually is over the left chest.
• A subcostal view should always document the abdominal
situs which may be variable.
• Dextrocardia should be differentiated from Cardiac
Dextroposition, which is defined as displacement of the
heart to the right secondary to extracardiac causes such
as right lung hypoplasia or diaphragmatic hernia.
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Variable Situs & Dextrocardia
S I A
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Dextrocardia in Adults
• Because we are concerned with Dextrocardia in adults, we
will consider only a limited number of possibilities:
Dextrocardia with L-loop ventricles and inverted great
vessels (Situs Solitus or Situs inversus totalis with
corrected TGA also called Mirror-Image Dextrocardia).
Generally discovered in the adult on routine chest x-ray or
physical exam performed for other reasons.
• Patients experience normal longevity of life and have
similar risks of getting acquired heart disease as do other
patients of the same age and sex. If angina pectoris or
myocardial infarction occurs, the pain is located in the right
anterior chest and radiates to the right shoulder and right
arm.
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Dextrocardia with Situs Inversus
and Corrected TGA
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Dextrocardia with Situs Solitus and Corrected TGA
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Atrial Morphology
• The right and left atria are identified morphologically by
their respective atrial appendages and veins emptying
into them.
• The RA receives IVC, SVC and coronary sinus.
• The LA receives all 4 pulmonary veins.
• The RA has a triangular, broad based, anterior
appendage while the LA has a narrow, fingerlike
posterior appendage.
• The septum secundum (limbus of the fossa ovale) lies on
the RA side. The septum primum (flap) lies on the LA
side. The Crista Terminalis is in the RA. LA is smooth
with fewer trabeculations.
• Almost invariably 2 atria are present although sometimes
there may be a common atrium if the IAS is absent.
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Normal Atrial Morphology (TEE)
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TEE views showing
triangular and broad
based
RA appendage.
Narrow, fingerlike LA
appendage.
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Normal Subcostal Images
IVC-RA Connection
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Atrial Situs (Arrangement)
• There are 3 possible atrial situs nomenclatures:
Situs Solitus (S), Situs Inversus (I), Situs Ambiguous (A)
= right isomerism (bilateral right atria) or left isomerism
(bilateral left atria).
• Atrial Situs Solitus (S): IVC, SVC and coronary sinus on
the right.
• Atrial Situs Inversus (I): IVC, SVC and coronary sinus on
the left.
• Atrial Situs Ambiguous (A): IVC is interrupted between
the renal and hepatic segments, hepatic veins drain into
common atrium, persistent left SVC (bilateral SVC) may
drain into unroofed coronary sinus and a muscle bar
similar to a crista terminalis may be present in the left
SVC-atrial junction. Variable pulmonary vein connections.
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Atrial Situs Ambiguous
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Ventricular Morphology
• The RV is distinguished by its triangular shape, coarse
trabeculations, heavy apical moderator band and chordal
attachments of the TV leaflets to the trabeculated septal
surface. Normal RV has a pumping chamber (RV sinus)
and an outflow tract (infundibulum).
• The LV is oval shaped with a finely trabeculated apex
(trabeculae carnea) smooth septal wall and MV chordal
attachments only to the free wall papillary muscles.
• The common situation is when two, well formed
ventricles are present. True “single” ventricles do exist
but it is usually possible to identify a rudimentary
ventricle attached to the side of the main ventricle. The
surgical outcome is better in those with a dominant LV.
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Ventricular Situs or Looping
• Normal rightward direction of looping is termed Dextro or
D-Looping (right hand topology)
• If the heart loops abnormally to the left, Levo or L-Looping
(left hand topology) occurs.
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Determination of Ventricular Situs by
Chirality (Handedness)
D-loop: palm of right hand over RV
septal surface, thumb in TV and fingers
in RVOT.
L-loop: palm of left hand over RV
septal surface, thumb in TV and fingers
in RVOT.
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Concordant or Discordant
Connections
• Connection : refers to the sequence of anatomic
structures. Normally, RA is connected to RV by means of
TV. RV is then connected to the PA by means of the PV.
Therefore, there are atrio-ventricular connections and
ventriculo-great arterial connections to identify.
• Concordance: describes the relationship between the
various chambers, valves, and great vessels. In the
normal heart all the connections and relationships in the
anatomic sequence are concordant.
• Discordance : describes abnormal relationships between
the various chambers and great vessels.
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Concordant or Discordant
Connections
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AV Connection/Alignment
• AV Concordance
• AV Discordance
• Tricuspid Atresia
• Mitral Atresia
• Common AV Valve
• Overriding AV Valve
• Straddling AV Valve
• Double Inlet Ventricle
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Arterial Morphology
• The definition of an aorta
is an artery that gives rise
to the coronary arteries
and the brachiocephalic
vessels.
• In contrast the pulmonary
artery branches into two
but does not give rise to
any vessels.
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Ventriculo-Arterial Connection
Concordant or Discordant
• When the aorta is connected to the LV and the
pulmonary artery to the RV the connection is described
as concordant.
• If the aorta is connected to the RV and the pulmonary
artery to the LV then the connection is discordant. This
is most commonly seen in transposition of the great
arteries (TGA)
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Ventriculo-Arterial Connection
Double Outlet
• If both great arteries arise from a single ventricle the
connection is described as double outlet.
• The great arteries may be normally related to each other
or mal-positioned (TGA).
• The situation is still described as double outlet even if
both vessels are not completely over a single ventricle.
• If more than 50% of an artery overrides a ventricle it is
said to be committed to it.
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Ventriculo-Arterial Connection
Single Outlet
One vessel only may arise from
the heart. This may be because a
vessel is absent (Aortic or
Pulmonary Atresia) as is the
case with the drawing on the left
or because the two vessels
have fused to form a common
outlet as seen in the drawing of a
Persistent Truncus on the right.
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Concordance or
Discordance
Double Outlet
Connection
Single Outlet
Connection
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Commitment
• Commitment further describes possible abnormalities of
flow through valves into ventricles and great vessels.
• In Tetralogy of Fallot, the atria, atrioventricular valves,
and ventricles are positioned normally, and concordant.
But the aorta overrides a VSD and is doubly committed
to both ventricles.
• In cases where there is only one ventricle (univentricular
heart), both atrioventricular valves are usually doubly
committed to the single ventricle.
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Ambiguous, Inlet, Outlet
• Ambiguous is used when precise identification of a
ventricle or other structure cannot be made. For
example, in a univentricular heart with a doubly
committed atrioventricular connection it may not be
possible to always identify clearly whether it is the right
or left ventricle. Thus, the single ventricle would be
ambiguous.
• Inlet refers to anomalies of the structures and flow into
the ventricle.
• Outlet refers to anomalies of the structures and flow out
of the ventricles into the great vessels.
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Types of Conus
• Subpulmonary: absence of subaortic infundibular free
wall, found in the normal heart.
• Subaortic: absence of subpulmonary infundibular free
wall, found in D-loop TGA.
• Bilateral: bilaterally present infundibular free wall, found
in double outlet RV but rarely in TGA.
• Bilaterally Absent: no infundibular free wall, found in
double outlet LV.
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Interrelations between the
Semilunar Valves
• Solitus (normal).
• Inversus (mirror image)
• 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 views as well
as subcostal short axis views are used to recognize the
positions of the AV and PV.
• The origins or the coronary arteries are also
documented.
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Formulation: Step 1
• The visceroatrial situs is determined: S, I or A.
• Visceroatrial situs refers to the position of the
atria in relation to the nearby anatomy
(including the stomach, liver, spleen, and
bronchi).
• Three different anatomic configurations may be
observed: S (situs solitus), I (situs inversus), or
A (situs ambiguous).
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Formulation: Step 2
• Ventricular Situs: D or L
The leftward L-loop (abnormal) or rightward D-
loop (normal) orientation of ventricular looping
is evaluated, and the positions of the ventricles
are identified on the basis of their internal
morphologic features.
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Formulation: Step 3
• The position of the great vessels is determined
first, and any abnormalities are noted: S, I, D L
or A. (S = Solitus)
• Abnormalities in the origin and position of the
great vessels (conotruncal anomalies) are
predominantly of 4 types:
• Inverted (I)
• D-Malposition (D)
• L-Malposition (L)
• Anterior (A)
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Normal {S,D,S} Anatomy
The Van Praagh segmental approach documents
the three major cardiac segments {atria, ventricles,
great arteries} in a venoarterial sequence.
Letters are coded in brackets { } to describe the
visceroatrial situs [S = situs solitus, I = situs
inversus, A = ambiguous], the ventricular loop [D =
D-loop, L = L-loop]), and the great artery position
[S = normally related great arteries, I = inverted
normally related great arteries, D = D-malposition,
A= Anterior malposition and L = L-malposition].
Thus, a normal heart would default to {S,D,S}
anatomy. Any other combination is abnormal.
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Main Sources
• Segmental Approach and Nomenclature. Tal Geva, MD of
Congenital Heart Disease. Department of Cardiology.
Children's Hospital Boston.
• Van Praagh R: The segmental approach to diagnosis of
congenital heart disease. In Birth Defects: Original
Article Series. Baltimore, Williams & Wilkins.
• Approach to Dextrocardia in Adults: Review
Pierre D. Maldjian and Muhamed Saric.
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