Congenitally Corrected Transposition
Of Great Arteries (CC TGA)
HISTORY OF CC TGA
• More than century before Karl von Rokintansky applied the term
‘’corrected’’ for undescribed form of transposition of great arteries.
• End of 18 th century MATHEW BAILLE described a ‘singular malformation’
characterized by discordant origin of arterial trunks from the ventricular
• 1957 – ANDERSON and co workers described the clinical manifestation of
the Rokintansky’s singular malformation
• And 4 yrs later SCHIEBER and co workers changed the term “corrected”
to “congenitally corrected” to clarify that correction was a gift of GOD and
not a gift of the surgeon
THE TERMS TO DEFINE
• Transposition- discordant origin of arterial trunks from the ventricular mass . Ao
from morpho Rt ventricle and PA from morpho Lt ventricle.
• D –loop – normal right word bend in developing straight heart tube of embryo ;
indicates that the sinus or inflow portion of morpho Rt ventricle is on right side of
morpho Lt ventricle
• L –loop- the sinus or inflow portion of the morpho Rt ventricle is to left of
morpho Lt ventricle
• Discordant loop – An L loop in situs solitus and D –loop in situs inversus
• Ventricular inversion – Atrioventricular discordance with Ventriculoarterial
concordance. Morpho Rt atrium is aligned with Lt ventricle from which aorta
arises and morpho Lt atrium aligned with Rt ventricle that gives rise to
TERMS TO DEFINE
Criss-cross hearts –
Atrioventricular connections are
not parallel (as in normal hearts )
but are angulated as much as 90 ̊.
It results from abnormal rotation of
ventricular mass around its long
axis and resulting in the
relationship that could not be
inferred from the inflow tracts.
• It typically occurs in situs solitus (5 %
situs inversus )
• Prevalence 0.5 % of clinically
diagnosed cardiac malformations and
1 in 13,000 live births
• Congenitally corrected transposition is
characterized by chambers that are
joined discordantly at Atrioventricular
junction and ventricles that are joined
discordantly at ventriculo- great arterial
• This double discordance – AV and VA
– physiologically corrects the
discordance intrinsic to each.
• When the heart tube bends to the left in situs solitus , the
morphological right ventricle lies on left of morphological
• Ventriculo arterial discordance is less well defined on
embryological basis .
• Some researchers thoughts that developmental fault at
infundibular segment and some argues that fault lies at
• Depends on the functional adequacy of sub aortic morphological
right ventricle and co-existing mal formations.
• The thick walled sub aortic Rt ventricle is supplied by the
concordant RCA which is designed to perfuse the thin walled low
resistance right ventricle.
• So this inverted right ventricle has high prevalence of myocardial
perfusion defects and abnormalities of regional wall motion.
• Ejection Fraction is considerably less than that of the normal sub
aortic left ventricle
• VSD , PS , abnormalities of left AV valve has considerable
impact on the functioning of the inadequate inverted right
• CC -TGA with no associated abnormalities are in fact the exception as 90 %
cases has abnormalities. Most common includes VSD , left ventricular
outflow tract obstruction and anomalies of left sided AV valve.
80 % of necropsy cases , non restrictive perimembranous type due to
mal-alignment of atrial and ventricular septum
Sub -arterial and muscular defects are unusual
• Pulmonary outflow obstruction
30-50% of cases , tissue tags are most common cause of obstruction ,
these tags are derived from membranous septum or mitral or
pulmonary valve itself .
Obstruction is associated with large VSD in 80% of cases and without
VSD IN remaining 20%.
• Abnormalities of left AV (tricuspid ) valve-
90% cases has anatomically abnormal valve but fairly
functions well in early life but age related increase in
regurgitation is seen.
Most common and important anatomical abnormality is
dysplasia of valve with or without of EBSTEIN’S like
anomaly and sometimes valve is stenotic.
Sometimes left and right AV valve can be straddling the
ventricular septum and it is important to identify them
Coronary artery pattern -
Coronary artery and
Coronaries shows mirror
Both Coronaries arises
from posterior sinuses and
anterior one is non
study from 56 specimen
reported 76% incidence of
relatively ‘normal’ pattern
with the right and left
coronaries originating from
left and right facing sinuses
RT SIDED COORONARY
ARTERY BIFURCATES IN TO
IT HAS MORPHOLOGY
LIKE LEFT CORONARY
CORONARY runs into
left AV grove and gives
it has a morphology
are common in CC -TGA
e.g especially like single
• HISTORY –
M :F =1.5:1
It shows monogenic transmission as it occurs in the first degree relatives
Isolated CC-TGA has asymptomatic childhood but clinical problems starts arising in
If symptoms occurs in infanthood may be due to bradycardia reflecting high degree AV
block, tachyarrhythmia, cyanosis and or CHF.
CHF due to large VSD or severe regurgitation in AV valve so clinical features suggestive
of mitral regurgitation in neonate should prompt consideration of CC-TGA.
Older child may be referred to a pediatric for loud second heart sound in suspicion of
pulmonary hypertension.(as aorta is placed left and anterior to)
• Patients may have angina pectoris which is attributed to a supply –
demand imbalance between a thick walled systemic right ventricle
and its blood supply from a morphological right coronary artery .
• Myocardial perfusion defects are prevalent due to this.
• VSD that accompanies CC TGA is typically non restrictive with
clinical course analogous to normally formed heart.
• PHYSICAL EXAMINATION
Retarded Growth and Development are seen with large
Ventricular Septal Defects and Congestive Heart Failure .
Cyanosis and Clubbing appear when pulmonary stenosis or
pulmonary vascular disease with reversal of shunt of
• ARTERIAL PULSE
Wave form is normal , rate reflects bradycardia.
Prolonged PR interval is recognized by an increase in the
interval between jugular A wave and carotid pulse and
CHB may be identified by random cannon A waves
Precordial Movement And Palpation
• Precordial movement is
influenced by ventricular
septum which is vertical and
• Rt ventricle forms the apex
laterally and medial border is
adjacent to left sternum
• so right ventricular impulse is
accentuated with large AV
• Left ventricle is behind the
sternum so not palpated even
in presence of PAH OR PS
• AORTIC component of second
heart sound is palpated
because of anterior position
• FIRST SOUND – soft due to prolonged PR
• SECOND SOUND –loud due to aortic valve is anterior
mistaken for PAH.
• VSD- produces holosystoloic or decrescendo murmur in
fourth LISC. May be associated with MDM left AV valve.
• Left AV valve regurg -generates systolic murmur analogous to
MR and it radiates to left sternal edge rather than to axilla.
• murmur of PS is heard mid left sternal edge rather than at
second LISC .
• Due to misaligned atrial and ventricular septum AV node and its
connections are different in CC TGA.
• Anomalous Anterior AV node is present with long bundle that penetrates
fibrous annulus and descends into the anterior aspect of the ventricular
• This long bundle is well formed in young children but in beginning of
adolescence this bundle starts replacing with fibrous tissue
• RBB and LBB are concordant with ventricles
• EBSTEINS malformation is associated with left sided accessory pathway
that provides substrate for pre excitation .
• The P wave
Is normal in direction and configuration but broad notched P
waves may be seen when left AV valve is regurgitant or large
VSD with L R SHUNT.
• AV BLOCK-
More than 75% pts exhibits varying degree of heart blocks
from PR prolongation to CHB, even in same pt block varies
from time to time
CHB associated with narrow QRS complex duration.
• QRS complex
Activation of septum is in reverse direction as that of normal
heart so Q wave will appear in right Precordial leads and will
be absent in left Precordial leads even in presence of volume
overload of systemic ventricle.
Left axis deviation is diagnostically important ; cause of this is
abnormal location of AV NODE and its connection with
ventricular conduction system .
• T wave
In more than 80% of cases T waves are positive in all six Precordial
leads a distinctive feature attributed to the side by side relation
ship of the inverted ventricle
Absence of Q waves
Upright T waves
8 yr old boy with CCTGA large non restrictive VSD
with left to right shunt
Broad notched P waves
• Narrow vascular pedicle
• ‘HUMP SHAPED’ appearance of
left cardiac silhouette of right
ventricle due to inverted
• ‘Septal notch’ – which is subtle
indentation just above the
diaphragm corresponding to inter-
• Echo examination of pt with complex AV AND VA connection should
begin with defining situs in abdomen .
• Sub costal views are important in identification of a case of CC TGA.
• First clue for presence of AV Discordance is Significant
malalignment between the atrial and ventricular septum.
• Look for features of right and left morphologic ventricles
• Short axis view at the level of aortic and pulmonary valves is very
useful in defining the anatomical position of aorta and pulmonary
• LEFT VENTRICLE
Ovoid or ellipsoid shaped
AV valve that inserts into
the ventricular septum
proximally than contra
Bicommisural valve with
fish mouth appearance
paired papillary muscle
and chordae tendineae
that inserts into free wall
Continuity between AV
valve and great artery
• RIGHT VENTRICLE
Distal insertion of AV valve
into the septum
Multiple irregular papillary
muscle with chordal
attachment to ventricular
Discontinuity between AV
valve and great artery
• Surgery is recommended only for symptomatic associated lesions and
when significant hemodynamic benefit is expected.
• The altered location of a fragile conduction system and the mirror image
coronary anatomy may complicate surgical repair,
• Ventricular septal defect closure is generally performed when symptoms
of CHF or failure to thrive do not respond to medical therapy or when
pulmonary vascular pressures are increasing.
• Tricuspid valve replacement can be performed for severe tricuspid
incompetence as repair of the dysplastic or displaced valve is not usually
• The atrial and ventricular double switch procedure is performed when
significant pulmonic stenosis and a large ventricular septal defect are
• Feasibility of the repair depends on the location of the ventricular septal
• The atrial switch for L-transposition takes the form of the Senning or
Mustard procedure with additional repair of any ventricular septal
defect. The arterial switch operation is the most current procedure
available, generally performed within 2 weeks of birth
• In a study of 52 patients reported by Termignon et al, the operative
mortality rate of a classic repair of congenitally corrected
transposition of the great arteries and ventricular septal defect was
16% and the rate of complete heart block was 24% after the repair.
• Survival rates were 83% at 1 year and 55% at 5 years after the
• Congenitally corrected transposition of the great arteries
without coexisting malformations is uncommon and
initially can go unrecognized.
• The clinical picture is dominated by pathophysiology of
associated cardiac anomalies.
• Ventricular septal defects are typically nonrestrictive and
perimembranous and are analogous to comparable
defects in hearts without ventricular inversion.
• Pulmonary stenosis regulates the left-to-right shunt
through a ventricular septal defect.
• Long term follow up of conventional surgical approach is
disappointing and has led to novel surgical approaches
aimed at restoring AV and VA connections.