PA/IVS is a rare congenital cardiac defect that consists of atresia of the pulmonary valve resulting in an absent connection between the right ventricular outflow tract (RVOT) and pulmonary arteries, and an intact ventricular septum that allows no connection between the right and left ventricles
5. History
• 4 days old Term baby
• Bluish discoloration noticed at 2 days
• Progressive increase in cyanosis
• Mild fast breathing noted
Note: Cyanosis coincident with ductal closure
Dyspnea with severe acidosis, reduced C.O. or pulmonary hypoplasia
7. Physical exam
• S2 single
• TR- PSM ± thrill at LLSB, MDM
• PDA- murmur in 2nd or 3rd LICS
• If TR severe or ASD restrictive
hepatomegaly
• If ASD restrictive compromising C.O.
peripheral pulses feeble
8. Blood gas
• Hypoxemia refractory to increased O2
• Hypocarbia from tachypnea
• Metabolic acidosis in severe cases
10. Massive cardiomegaly in a newborn
may be seen in all except:
A] Ebstein’s anomaly and functional
pulmonary atresia
B] Pulmonary atresia and Ebstein’s anomaly
C] ccTGA, severe left AVVR and functional
aortic atresia
D] Intrapericardial teratoma
E] None of the above
18. Role of Echo: To determine
• Size of atrial communication
• Size and morphology of tricuspid valve
• RV morphology & inflow and outflow dimensions
• Anatomical vs functional pulmonary atresia
• Branch PA size and continuity
• Presence of pulmonary blood flow from PDA
• Coronary artery anatomy & connections with RV
20. Atrial septum
Associations:
• PFO or OS ASD with
obligatory R to L
shunt
• If ASD restrictive,
septum primum may
become aneurysmal
& herniate through
mitral valve
Subcostal view: IAS with
aneurysmal flap, R-L shunt
Image: pedcards.com
21. Atrial septum
• Shunting at the atrial
level is bidirectional
but primarily R-to-L
• Oxygenated pulmonary
venous blood shunts L-
to-R across TV
perfuses the
myocardium (via the
RV-coronary fistulae)
• Nonrestrictive flow is
essential
Image: Thoracickey
22. Coronary sinus
Associations with PA IVS:
• Stenosis/ atresia of coronary sinus ostium
with decompression through unroofed
coronary sinus
• If atrial septum intact, coronary sinus-LA
fenestration may be seen
27. Right ventricle
• Heterogeneity in RV
size, inlet, TV
competency and RV
function
• Z value of tricuspid
annulus correlates
with RV cavity size
• May be described as
tripartite (with inlet,
apical trabecular &
outlet components) or
underdeveloped
Image: JACC
29. LVOT
• May be obstructed
by bulge in outlet
septum in small and
high-pressure RV
• LVOTO worsens after
Fontan
Image: pedcards.com
PSAX view:
IVS bowing into LVOT
34. Pulmonary arteries
• Usually MPA is present; pulmonary arteries
are confluent & fed by left-sided PDA
• If non-confluent PAs, bilateral PDAs or
MAPCAs seen
• LPA coarctation may occur at site of PDA
insertion
36. Coronary arteries
Associated abnormalities of coronaries:
Subepicardial coronaries develop
sinusoidal or fistulous connections with RV
Absence of proximal aorto-coronary
connection
Coronary artery stenosis or interruption
Coronary cameral fistula between RCA/
LMCA and RV
37. Ventriculocoronary connections & RV
Ventriculocoronary connection correlates with:
• Negative tricuspid valve Z value (Z score < -2.5)
• RV classified as unipartite or bipartite
Hypertensive RV with myointimal hyperplasia,
background of glycosaminoglycans, endothelial
irregularity, obliteration of lumen
38. Image: doctorlib
A4C view of posterior RV and LV at level of Coronary sinus:
Multiple coronary sinusoidal channels within RV myocardium
39. Ventriculocoronary connections
• Ventriculocoronary connections may promote
coronary stenosis
• Normal aortic diastolic pressure may be
insufficient to drive coronary blood flow if
obstructive lesions present
• If palliative measures like PGE1 or BT shunt
further lower diastolic pressure, aortic
diastolic pressure insufficient for coronary
perfusion
40. Image: doctorlib
PSAX view: Dilated proximal
RCA with retrograde filling
Ventriculocoronary connections
• Myocardial perfusion
sustained by
retrograde coronary
flow from
hypertensive RV
during systole
• Systemic or
suprasystemic RVSP
Further coronary
distortion
• Any decrease in RV
blood flow or RVSP
coronary ischemia
41. Image: Giglia et al, Circulation
Potential of adverse outcome after
RV decompression:
RV to coronary
Fistula without
coronary stenosis
Potential RV steal
phenomenon
RV to coronary Fistula
with proximal ± distal
coronary stenosis
Potential RV steal/
ischemia
RV to coronary Fistula
with Coronary
occlusion/ atresia
Potential Isolation
and MI
42. This superior view demonstrates an atretic pulmonary artery (PA) with a LCA to RV fistula
43. Hypoplastic RV (HRV) with RCA to RV fistula.
Ebstein-like malformation of the septal leaflet of TV
46. Role of Cardiac cath.
• Coronary artery abnormalities (Color doppler
cannot image obstructions to the coronary
arteries with the precision of angiogram)
• BAS if PFO restrictive
• RV pressure- If low, suggests functional rather
than anatomical PA Or global RV dysfunction
• RV Angiogram- RV morphology & for
ventriculocoronary connections
• Aortography- PDA, pulmonary arteries
48. Angiographic criteria for diagnosis of RVDCC
Stenosis of ≥ 2 major coronary arteries (LMCA, LAD,
circumflex or RCA)
Or
Atresia of the coronary ostia
And
Myocardium distal to the obstruction receiving blood
supply via fistulous connections from RV
Evidence of myocardial ischemia on surface ECG following
catheter placement in RV is suspicious for RVDCC
(Decompression of RV from catheter-related TR)
49. Angiographic diagnosis of RVDCC
Angiographic techniques (Galindo et al):
• RV angiogram
• Aortogram
• Aortogram with balloon occlusion of the aorta
• Selective coronary angiograms
50. RV injection:
Fistula to mid LAD with stenosis proximal to fistulous insertion
LAD irregular proximally with additional proximal stenosis
RCA fills from collaterals to LAD
51. Image: Sakurai, JTCVS, 2018
Lateral view Aortography: No
coronaries arising from aorta
Right ventriculogram:
Proximal RCA, distal RCA &
LCA arising from RV
53. In utero development of coronary a.
abnormalities
Lack of blood-egress
from RV
Elevated RV pressure
Blood forced
retrograde through
thebesian veins
Coronary
sinusoids
(enlarged
thebesian veins)
Fistulae (enlarged
thebesian veins
communicating
with epicardial
coronary arteries)
Image: Thoracickey.com
54. In utero development of coronary a.
abnormalities
High pressure
retrograde flow
through epicardial
coronaries
Endothelial
damage
Coronary
stenoses
55. Fetal echo findings
• TV orifice proportional to
RV size
• TV often dysplastic TR
or TS
• Dilated RA common
• Increased R-L shunt
through PFO Dilated LV
• Foraminal flap may be
redundant
Small, hypertrophied RV; small PE
28 weeks fetal echo
Image: contemporaryobgyn.net
56. Fetal echo findings
• MPA may be
normal caliber
• Ductal flow
reversal
essential
finding
Retrograde blood flow through
the ductus
Image: contemporaryobgyn.net
28 weeks fetal echo
58. Role of Fetal Echo
Predictors for the postnatal surgical pathway:
• Combination of z-scores of fetal cardiac
measurements and tricuspid/mitral valve
(TV/MV) ratios
• Presence of coronary fistulae (usually predicts a
single ventricle route)
• RA pressure based on PFO (normal or
restrictive), TV dimension and competency,
ductus venosus Doppler (abnormal if end-
diastolic flow absent or reversed)
59. Predictors of Biventricular repair
• Fetal echo can predict biventricular circulation
(at 26 weeks gestation) with 92% specificity
• Best predictive scores for specific gestations:
PV z-score (23 weeks)
Median TV z-score (26 weeks)
Combination of median PV z-score and TV/MV
ratio (26 to 31 weeks)
Combination of median TV z-score and TV/MV
ratio (31 weeks)
60. Predictors of poor outcome
• Fetal TV z score ≤ of −4 beyond 23 weeks of
gestation
• Fetal TV annulus of ≤ 5 mm beyond 30 weeks of
gestation
• RV:LV length or width < 0.5
• Absence of TR
Peterson RE, et al.J Am Soc Echocardiogr. 2006.
61. Take-home messages
Diagnosis of PA IVS should include:
• 1) Adequacy of PDA to sustain adequate pulmonary blood flow;
adequacy of ASD for decompression of systemic venous return
to LA
• 2) Size of RV; presence or absence of inlet, trabecular and/or
infundibular portions
• 3) Evaluation of RVOT, anatomic nature of pulmonary valve
(muscular/ membranous)
• 4) Any evidence of opening in a membranous pulmonary valve,
esp. if presence of PR
• 5) Evaluation of TV annulus diameter, any sign of Ebstein’s
anomaly, related chordal attachment abnormalities
• 6) Identification of coronary artery abnormalities and/or RVDCC
62. References
• Nykanen DG. Pulmonary atresia and intact ventricular septum. In Ed.
Allen HD, Driscoll DJ, Shaddy RE, Feltes TF. Moss and Adam’s Heart
Disease in infants, children and adolescents. Seventh ed. Philadelphia,
Lippincott Williams and Wilkins
• Peterson RE, Levi DS, Williams RJ, et al. Echocardiographic predictors of
outcome in fetuses with pulmonary atresia with intact ventricular
septum.J Am Soc Echocardiogr. 2006;19:1393-1400.
• Liu L, Wang H, Cui C, et al. Prenatal echocardiographic classification and
prognostic evaluation strategy in fetal pulmonary atresia with intact
ventricular septum. Medicine (Baltimore). 2019;98:e17492.
• Giglia TM, Mandell VS, Connor AR, et al. Diagnosis and management of
right ventricle-dependent coronary circulation in pulmonary atresia
with intact ventricular septum. Circulation. 1992;86:1516-1528.
Hinweis der Redaktion
PSAX view: Dilated LCA filling retrograde
RAP score >3 predicts a biventricular repair
Liu L, et al. Medicine 2019: In fetal PA/IVS, TV z-score >-3.28, TV/MV >0.71, RV/LV length >0.62, TID/CCD >33.95%, moderate and severe TR, and the absence of VCAC were associated with postnatal biventricular repair strategy