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Pulmonary atresia with intact ventricular septum
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Pulmonary atresia and intact ventricular septum was
first described in 1784 by Hunter
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Robert M. Freedom- described the diversity of this
malformation and emphasized the complexity of this
disorder
Epidemiology
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New England Regional Infant Cardiac Program
identified 75 patients with this disorder- 3.1% of all
infants enrolled in the study
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Baltimore-Washington Infant Study defined the
prevalence for this disorder as 0.083 per 1,000 live
births
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Levocardia, normal atrial relations, concordant
atrioventricular connections, and concordant
ventriculoarterial connections
Right ventricular outflow tract is imperforate.
Either membranous or muscular atresia.
The ventricular septum is intact.
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Pulmonary blood flow is usually mediated by a PDA
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Multiple direct aortopulmonary collaterals originating
from the descending thoracic aorta may be the sole
sources of pulmonary arterial supply rarely.
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Nonconfluent pulmonary arteries, each supplied by a
patent arterial duct may also occur rarely.
Morphogenesis
Kutsche and Van Mierop theory
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Pulmonary atresia with ventricular septal defect occurs
earlier in cardiac morphogenesis than pulmonary atresia
and intact ventricular septum.
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Pulmonary atresia and ventricular septal defect occur
early in cardiac morphogenesis, after partitioning of the
truncoconal part of the heart but before closure of the
ventricular septum.
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Pulmonary atresia and intact ventricular septum occur
after cardiac septation.
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Reflects a prenatal inflammatory disease rather than a
true congenital malformation
Kutsche LM, Van Mierop LH. Pulmonary atresia with
and without ventricular septal defect: A different
etiology and pathogenesis for the atresia in the 2 types?
Am J Cardiol 1983;51:932â
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Few data to support an inflammatory process
Histopathological studies provided no evidence of
inflammation.
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Obligatory right-to-left shunt at atrial level-either a
patent foramen ovale or true secundum atrial septal
defect
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If the interatrial septum is intact -alternative pathways
for systemic venous return - coronary sinus to left
atrial fenestration.
Tricuspid Valve
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Ranges from extreme stenosis to severe regurgitation
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Severely regurgitant valve -dilated annulus.
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The valve may exhibit Ebstein anomaly.
Extremely dysplasia also seen.
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Patients with the largest right ventricles usually have
severe tricuspid regurgitation with valves exhibiting
features of Ebstein's anomaly and dysplasia.
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A major management challenge with a poor overall
prognosis.
Right Ventricle
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Congenital Heart Surgeons Study (CHSS)-the use of the
tricuspid diameter Z value
It is the diameter of the tricuspid valve normalized to
body surface area.
Data from the CHSS showed that the Z value of the
tricuspid valve correlated with the size of the right
ventricular cavity (p <0.0001)
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Relief of outflow tract obstruction with associated
pulmonary insufficiency may result in remodeling with
regression of hypertrophy that can result in real or
perceived growth of the right ventricle
Daubeney PE, Delany DJ, Anderson RH, et al. Pulmonary
atresia with intact ventricular septum: Range of morphology in a
population-based study.
J Am Coll Cardiol 2002;39:1670
Freedom RM. How can something so small cause so much grief?
Some thoughts about the underdeveloped right ventricle in
pulmonary atresia and intact ventricular septum.
J Am Coll Cardiol 1992;19:1038
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Well developed RV with hypertrophy-inlet,trabecular
and outlet well developed -good prognosis.
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Small RV cavity (66%)-poorer surgical outcomes
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Markedly increased RV dimensions-severe
TR(associated Ebsteins anomaly- 10-15 %)
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The aortic arch is left sided
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Aortic valve stenosis has been described in patients
with pulmonary atresia and intact ventricular septum
Myocardial Abnormalities
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Ischemia, fibrosis, infarction, and myocardial rupture
have been observed
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Myocardial disarray and ventricular endocardial
fibroelastosis also seen.
Ventricular to coronary artery communications
PA IVS is associated with ventriculo arterial
connections(by large sinusoids)
 Usually seen in association with hypoplastic RV
 Connections are seen to commonly RCA,LAD
(to LCX is rare)
Blood flow
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Systole-High pressure RV to sinusoids
Diastole-coronary artery to RV- ‘coronary steal'
Development
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Coronary circulation develops as isolated plexus of
vessels.
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Connections first develop to ventricular cavity and later
coronary arteries develop and connect to aorta.
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Pulmonary atresia-high RV pressure maintains RV to
sinusoids patency
Coronary artery anomalies
1) right ventricle -to-coronary artery fistulas
2) coronary artery stenoses
3) coronary occlusions
Natural History
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Equal prevalence in male and female
50% newborns die in first month of life
Majority die in first 3 months
Survival beyond first year is rare.
Survival upto 21 years reported.
Physical Examination
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Newborns with pulmonary atresia and intact ventricular
septum become cyanotic and hypoxemic –along with
closure of the patent arterial duct
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Cyanosis usually is apparent within hours of birth and is
progressive
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The left ventricle may be enlarged, and at the apex, its
impulse may be forceful.
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The second heart sounds is single.(A2)
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A pansystolic murmur may be audible at the left lower
sternal border(of tricuspid regurgitation.)
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Arterial duct murmur may be heard in the second and
third left intercostal space
Radiographic Features
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The chest radiograph may demonstrate a heart that is
only mildly enlarged or one that fills the entire chest
cavity
Electrocardiographic Features
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Frontal QRS axis of + 30 to + 90
paucity of right ventricular forces
left ventricular dominance or left ventricular
hypertrophy
Right atrial enlargement
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The Electrocardiogram in Tricuspid Atresia
and Pulmonary Atresia with Intact
Ventricular Septum
Circulation.1966; 34: 24-37
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Electrocardiograms were studied in 37 patients
with tricuspid atresia and in 20 with pulmonary
atresia and intact ventricular septum.
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The results were correlated with
angiocardiographic findings and postmortem
examinations
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Biatrial hypertrophy was noted in 81% of the
electrocardiograms in patients with tricuspid atresia,
whereas this pattern was seen in only two infants with
pulmonary atresia and intact ventricular septum
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In tricuspid atresia, left axis deviation was more
common.
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Pulmonary atresia - no instances of left axis deviation
in the frontal plane.
Echocardiographic Features
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Functional status of the interatrial septum - obligatory
right-to-left shunting.
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The size and morphology of the tricuspid valve ,RV
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Patency of ductus
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Degree of TR
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Ebsteins anomaly
Functional pulmonary atresia
Lack of forward flow is due to high pulmonary artery
pressure with poor right ventricular function or very
severe tricuspid insufficiency.
Pulmonary valve is morphologically normal but
functionally closed
Cardiac cathetrisation
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Groin approach
Catheter passed through IVC to RA
Easily passes to LA(PFO)
RV entry difficult if severe TR/RV hypoplasia
Ductus visualised by left ventricular angiogram
Visualisation of coronary arteries
RV angiogram
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ventricular coronary communications
confirm PA
Management
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PGE1 infusion to maintain ductal patency
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Electively intubated and controlled ventilation
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Metabolic acidosis to be corrected and ionotropic
support if perfusion is inadequate
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Adequately stabilized before any initial procedure
Surgical management
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Goal is to achieve a two ventricular circulation with the
right ventricle providing all blood flow to the lungs at a
low filling pressures without residual right to left shunt
•
Goal should be achieved with
• low moratality
• promoting the growth of RV
• minimizing the need for subsequent surgical
procedures
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RV cavity size and coronary artery anatomy are crucial
in selecting appropriate treatment strategy
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The options available include the following.
Surgical opening of the pulmonary valve and the
right ventricular outflow tract.
Systemic arterial to pulmonary arterial shunt
Transcatheter opening of the pulmonary valve.
Maintaining ductus arteriosus patency.
Systemic venous to pulmonary arterial shunt.
Closing the tricuspid valve.
Venous to pulmonary arterial shunts
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Glenn procedure: end-to-end anastomosis of the SVC
to the left pulmonary artery.
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Cavopulmonary anastomosis or bidirectional Glenn
procedure: anastomosis of the SVC to the pulmonary
artery so that both lungs can be perfused by SVC
blood.
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Atriopulmonary connection or Fontan procedure:
Anastomosis of the right atrial appendage to
the pulmonary artery to divert all venous return
into the pulmonary artery.
Severe pulmonary stenosis or pulmonary
atresia with well-developed right ventricle
and mild or no tricuspid regurgitation
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Surgical pulmonary valvotomy with patch
closure
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Balloon valvuloplasty
Pulmonary atresia with well-developed
right ventricle and marked tricuspid
regurgitation
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SVC to pulmonary artery communication (bidirectional
Glenn procedure) can be performed in addition to
valvotomy.
Pulmonary atresia with hypoplastic right
ventricle and tricuspid valve
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Tricuspid valve diameter less than 8 mm in a
newborn infant
Tricuspid to mitral valve diameter ratio less than
0.7
Tricuspid valve diameter Z-scores of –3 or
smaller
Management
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Bidirectional Glenn procedure
Pulmonary atresia with hypoplastic right
ventricle and coronary sinusoids
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Attempts to open the RVoutflow tract are
contraindicated.
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Systemic-to-pulmonary arterial shunt or prolonged
PGE1 infusion is recommended.
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After the age of 3–4 months, cavopulmonary
anastomosis may be performed.
Risk factor for death after initial
procedure
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Low birth weight
Small tricuspid valve
RV dependent coronary circulation
Prognosis and long-term results after
procedures
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Balloon valvuloplasty performed in the neonatal period
may not be very effective in relieving stenosis.
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Cyanosis may persist and repeat valvuloplasty may be
necessary within 6–9 months.
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Residual pulmonary valve insufficiency
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Pulmonary atresia with intact ventricular septum:
Strategy based on right ventricular morphology
Naoki Yoshimura, MD, Masahiro Yamaguchi, MD
et al
J Thorac Cardiovasc Surg 2003;126
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Between April 1981 and June 2002, 45 consecutive
patients with pulmonary atresia with intact ventricular
septum underwent surgical treatment.
Open transpulmonary valvotomy was performed in
27 patients and Blalock-Taussig shunt in 18 patients as
the initial palliative procedure.
Three patients who underwent a
successful transpulmonary valvotomy alone in the
neonatal period required no further operation.
Definitive repair was performed in 32 patients
RESULTS
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There were 1 early and 2 late deaths before the
definitive operation in patients who underwent
transpulmonary valvotomy.
Two patients who had coronary artery interruption died
3 months and 13 years after the initial Blalock-Taussig
shunt.
There were 1 early and 2 late deaths after the definitive
operation.
Survival, including noncardiac death, was 91.1% at 5
years after the initial procedure and 81.5% at 10 years
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OUTCOME AFTER OPERATIONS FOR
PULMONARY ATRESIA WITH INTACT
VENTRICULAR SEPTUM
Jack Rychik MD, Hara Levy MD et al
J Thorac Cardiovasc Surg 1998;116
Overall survivals at 1, 5, and 8 years were 82%, 76%,
and 76%.
Mortality was highest in infancy
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Prenatal Diagnosis of Pulmonary Atresia
with Intact Ventricular Septum
Flow through the foramen ovale- moving from the
right atrium to the left atrium.
Retrograde flow through the ductus arteriosis
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