Tetralogy of Fallot is a congenital heart defect characterized by four abnormalities: pulmonary stenosis, ventricular septal defect, overriding aorta, and right ventricular hypertrophy. It was first described in detail by Etienne-Louis Arthur Fallot in 1888. Treatment options include medical management of symptoms as well as surgical repair to improve pulmonary blood flow and correct the defects. The document provides extensive details on the anatomical features, clinical presentation, diagnostic evaluation, and surgical/interventional management of Tetralogy of Fallot.

1. Dr Dhanesh Kumar

2. Definition
 Tetralogy of Fallot is a congenital cardiac
malformation characterized by underdevelopment of
the RV infundibulum, with anterior and leftward
displacement of the infundibular septum and its
parietal extension .

3. Historical Note
 TOF was first treated surgically by Blalock and
Taussing

4.  First anatomic description by Danish anatomist Niels
Stensen, in 1672.
 Described in detail by Fallot in 1888…’la maladie bleue’
 Tetralogy of fallot with pulmonary atresia=10%
 Rarer variants include tetralogy of fallot with absent (or
dysplastic) PV and TOF with common AV canal[<5%]

5.  Prevalence = 0.26 to 0.48 per 1,000 live births
 In about 70% of tetralogy of Fallot patients, a putative
genetic etiology remains to be determined.
Genetic cause : heterogeneous
 Genes identified :
 NKX2.5, [4%];
 JAG1 in Alagille syndrome.;
 TBX5 in Holt-Oram syndrome.
 Sibling recurrence rate =2.5% to 3% if only one sibling is
affected, likely to increase substantially if more than one
sibling is affected.

6. Environmental factors
 Maternal diabetes [threefold increased risk]
 Retinoic acids
 Maternal phenylketonuria (PKU)
 Trimethadione

7. Syndromes and associations
DiGeorge/Velocardiofacial syndrome,
Down syndrome
Alagille syndrome
Cat's-eye syndrome
Recombinant chromosome (or San Luis Valley) and Kabuki
syndromes
CHARGE
VATER/VACTERL associations.
Microdeletion on 22q11 seen in
 15–35% of TOF patients;
 45% of TOF + PA;
 65% of those with TOF + APV.

8. Developmental Fault
 Defective embryonic neural crest migration abnormal
conotruncal development.
 Incomplete rotation and faulty partitioning of the
conotruncus during septation.
 Malrotation of truncal-bulbar ridges results in
misalignment of the outlet and trabecular septum and
consequent straddling of the aorta over the malaligned
VSD.
 Abnormally anterior septation of the conotruncus by the
bulbotruncal ridgessubpulmonic obstruction

9. TOF
 4 anatomic
malformations:
-RVH
-PV Stenosis
-Transposition of
the aorta
-VSD

10.  Tetrad =RVOT obstruction, aortic override, VSD, and RVH
PS
Most characteristic= subpulmonic stenosis
 Obstruction along the entire course of the RVOT and
pulmonary arteries (LPA commonly) can occur.
 In general, the more severe the proximal obstruction, the
greater the likelihood of distal areas of obstruction
 Obstruction within the RV body.
 1)Hypertrophy of the septoparietal muscle bundles
2)Anatomic displacement of the normal moderator band
attachment

11. PV=bicuspid in 40%
VSD : nonrestrictive=Few ptsVSD restrictive d/t the
accessory TV prolapsing through the defect
Coronary Anomalies
 LAD from RCA (5%) & coursing in front of infundibulam
(Sx imp)
 Single coronary (4%)
So coronary evaluation before Sx imp
 Echo=proximal coronary
 If needed –Root angio / CAG - MRI/CT

12. RCA
LAD
LCX
AO
PA
LAA
LAD
RCC
NCC
RCA
LCx
Pulm.
Valve
MPA

13.  Right Aortic Arch in 25%,Twice more common in TOF+PA
 Aortopulmonary Collateral Arteries=MC with TOF +
PA,Only type 1, or
 Bronchial artery collaterals, were documented in TOF with
PS.
 Stenosis of LPA in 40%

14. Associated cardiac abnormalities
PFO or a true atrial defect in 83% of hearts with TOF
AVSD (downs)
LSVC(11%)
Left heart lesions are rare…Aortic valve disease may be
acquired as a result of surgical trauma, progressive
root dilation, or 20 to endocarditis.
TOF with Absence of PA almost always LPA
PS murmur radiates to Rt chest
CXR=Lt hemithorax small, Lt lung hypovascular ,Lt
hemidiaphragm elevated

15. Morphology of Pulmonary Arterial Supply
 3 major patterns :
(1)Most favourable= R/L PA are confluent, and are supplied
by an arterial duct [unifocal]
(2)The intrapericardial pulmonary arteries are confluent, but
co-exist with systemic -to pulmonary CAs.
(3)Absence of the intrapericardial pulmonary arteries,so fully
supplied by multiple systemic-to-pulmonary CAs.

16.  Unifocal….. usually the persistently patent arterial duct;
rarely solitary systemic-to-pulmonary collateral artery/AP
window/fistula from the coronary arteries.
 Multifocal MAPCAs: typically 2-6 in number; usually arise
from the anterior wall of the aorta opposite the origin of
the intercostal arteries. It is a rule that an arterial duct will
not be present when a lung is supplied by systemic -to
pulmonary CAs.

17.  The key to complete clinical diagnosis is to
establish the course of each artery, to establish
whether it runs directly into the lung or makes
connections with intrapericardial and central
pulmonary arteries, and to identify with precision
the sites of these anastomoses.
 Acquired CAs[TOF with PA] = join the pulmonary
circulation at immediately precapillary level.

18.  APCs …the Rt upper artery supplies exclusively the RUL in direct
fashion…Rt lower artery feeds the middle and lower lobes of the Rt lung
through an anastomosis with the intrapericardial arterial tree, shown in
blue, at hilar level….Left side…CAs are shown feeding the Lt lung through
anastomoses at segmental level.

19. (1)Absent intrapericardial PAs (2) Anastomoses between the CAs
and the intrapericardial PAs
(extrapulm, hilar, lobar,segmental)

20. Pathophysiology and Hemodynamics
 Severe cyanosis in profound RL shunting,
 Some pts have a net LRshunt.
 Hemodynamic features…RV hypertension because of the
large VSD, with normal or low PAP. The low distal PAP is
maintained as a result of the various levels of pulmonic
obstruction. The PVR in the distal pulmonary arterial bed is
usually normal.
 The extent and direction of shunting ,determined by the
cumulative amount of obstruction to PBF(Subpulmonic
obstruction in all; obstruction @ valvular, supravalvular,
and branch arteries are also common).

21.  Balance between PBF & aortic BF will be determined by the
difference in impedance between the unobstructed ,high-
resistance systemic vascular bed and the obstructed
pulmonary outflow tract and vascular bed.
 RVH in proportion to LV mass in nonrestrictive VSD.
 In restrictive VSD(suprasyst RVP)..severe RVH
 Obstruction to PBF is relatively fixed & variation in cyanosis
is determined by the changing SVR
 Hypercyanotic episode…thought to result from an acute
increase in infundibular obstruction and a proportional
decrease in PBF.

22. C/F :
 Wide due to variable severity of RV outflow obstruction
 USGfetal diagnosis
 Newborn & infants=cyanosis; systolic murmur
 Acyanotic TOFmild pulmonary overcirculation rarely
CHF unless there is a large PDA or aortopulmonary
collateral arteries
 Pregnancy=poorly tolerated , gestation decrease in SVR
increases R-L shunt & the labile SVR during labor ,delivery
leads to abrupt hypoxemia,high fetal wastage / dysmature
offspring

23. HYPERCYANOTIC SPELLS OR TETRALOGY SPELLS :
 Best described in TOF;can occur with other forms of
structural heart disease…. mediated, in part, by dynamic
changes (acute increase)in subpulmonic obstruction…..
changes in contractility due to ‘endogenous
catecholamines or exacerbated by hypovolemia’
 other mechanisms[pulmonary atresia and VSD] ….
decrease in systemic vascular resistance.
 Child may assume squatting posture (instinctive) during
spells …
Pathogenetic mechanisms : Vulnerable respiratory control
centres ;Increase in HR ; Increase in CO & VR ;Increase in R
L shunt; Infundibular contraction may reinforce,but does not
initiate

24. TYPICAL SPELL :
 The child becomes distressed and inconsolable, without
apparent reason, most often in the morning.
 Peak incidence2nd-6th m ;few after 2 yrs
 Crying is associated with progressively deeper cyanosis and
hyperpnea (not tachypnea).
 Spells are self-aggravating;
 During the spell  diminished/absent murmur
 Not infrequently,the spell terminates with unconsciousness
and, rarely,convulsions. If the hypoxemia is extreme,
permanent neurologic sequelae and even death may ensue.
True hypercyanotic spells are rare in neonates, although
cyanosis may increase with crying.

25. O/E :
o cyanosis ; clubbing ;
o Arterial pulses …normal in uncomplicated TOF;
o Wide pulse pressure (arterial diastolic runoff)…. aortopulmonary
collaterals, palliative surgical shunt or PDA;
o Accentuated precordial RV impulse;
o LV impulse will not be hyperactive (normal cardiac output);
o S2 single& loud (anterior, dextroposed aorta);
o S3/S4 are unusual;
o Aortic ejection click;
o Systolic murmur…crescendo-decrescendo @ LUSB. The intensity of
the murmur inversely parallels the degree of pulmonic obstruction;
o Diastolic murmurs are unusual..Rarely AR murmur;
o TOF with PA…..no harsh, obstructive precordial murmurs;
o A harsh diastolic murmur, with a harsh murmur of PS, [harsh
sawing, to-and-fro murmur ] ……TOF and APV syndrome;
o Continuous murmurs….PDA;aortopulmonary collaterals ;may be best
heard in the back.

26. ECG
 QRS axis … same as that of a normal newborn
 RVH…Tall monophasic R in V1 with an abrupt change to
an rS pattern in V2 (Tall R extends into adj precordial leads
in TOF + APV)
 Reduced PBF+ underfilled LVrS in V2-V6
 Balanced shunt …qR in V5,V6
 L-R shuntQR in V5,V6
 LAD with counterclockwise depolarisn TOF+AVSD

27. CXR:
 Normal sized heart; [may be large in PA]
 upturned apex; attenuated & concave left heart border
(infundibular and PA hypoplasia)….boot-shaped heart, or coeur
en sabot…small underfilled LV that lies above horiz IVS,
inferior to which is a concentric hypertrophied nondilated RV
 Diminished pulmonary vascularity in proportion to the degree
of cyanosis.
 Absent thymic shadow in the newborn may indicate associated
chromosome 22q11.2 microdeletion (DiGeorge syndrome).
 RAA in roughly 25%...accompanied by Rt DA on Rt side
 In PA..lacy reticular pattern (d/t the anast b/w lobar/segm PAs &
CAs)
 Syst arterial collaterals rarely cause rib notching as they do not
run in intercostal grooves.

29. ECHO: PLAX :
 VSD; degree of aortic override;
 ?bilateral conus;
 AR;
 Doppler… low velocity R-L shunt;
 dilated CS…..?LSVC;
 Absent DA..R/O RAA
Cranial tilt of the transducer…..infundibulum and the proximal
pulmonary arteries. [location and degree of infundibular, valvular, and
arterial hypoplasia]
Basal SAX:
 RVOT and proximal pulmonary arteries…degree of PS….PDA?
 VSD [just below the RCC, or at 10 o'clock position]. Tricuspid-aortic
continuity confirms the perimembranous nature.
 Coronaries…origin and course … echo showed sensitivity of 82%,
specificity of 99%, and accuracy of 98.5% in a study by Need et al
high parasternal and suprasternal views will provide visualization of
the pulmonary arteries and aorta, respectively

30. The anomalous LAD crossing the RVOT in TOF is identified when the transducer is swept
superiorly in the parasternal short -axis view . This allows visualization of the anomalous LAD
that is situated anterior to the RVOT
LAD
RCC
NCC
RCA
LCx
Pulm.
Valve
MPA

31. Here a normal LAD (arising
from the LCA and coursing
posterior to the pulmonary
valve) and a normal RCA are
shown in the top frames for
comparison.
RCA
Ao
LAA
Pulm valve
Ao

32. 64-slice HRCT :
Questions about preoperative pulmonary artery anatomy,
coronary artery anatomy, and systemic or pulmonary venous
anatomy can frequently be resolved even in newborns with
64-slice high-resolution CT scans.
CMR : Assessment of pulmonary anatomy
Postoperative assessment of RV function, myocardial
scarring, and PR fraction

33. Cardiac Catheterization
 Less often needed ;
 Diagnostic
 Therapeutic
 foremost goal …. clarification or better definition of
anatomic characteristics, such as pulmonary arterial or
coronary arterial anatomy
 coronary artery anatomy … either by aortic root angio,
selective coronary artery injection, or a combination of
both.
 Definition of any aortopulmonary collaterals ….usually
originate from the descending aorta.

34. MANAGEMENT

35. Medical Management
 ductal-dependent pulmonary blood flow ?......neonates with
critically restricted antegrade blood flow need to be started on
prostaglandin E1and considered for either total repair or a
systemic-to-pulmonary shunt.
 Most newborns with TOF do not have ductal-dependent
pulmonary blood flow and may be followed without specific
early intervention.
 Parental education for recognition of cyanotic spells [even
acyanotic TOF are at risk for the development of spells in the
first months of life].
 IE Prophylaxis for cyanotic/palliated patients ; patients for 6
months after patch repair surgery, and those with prosthetic
valves

36. Hypercyanotic spells …Rx aims @ lowering impedance to
pulmonary flow and further increasing systemic vascular
resistance.
Rx…..oxygen, volume expansion, sedation with morphine or
ketamine, and, if needed, vasopressors[phenylephrine]
Refractory to above …..
 Transfusion of whole blood/red cells
 Balloon angioplasty of pulm annulus
 Emergent surgical palliation or repair
Propranolol …having some efficacy in minimizing or
extinguishing the occurrence of spells. It may be used for
patients who are awaiting surgical intervention or who have
a medical contraindication to either complete repair or
aortopulmonary shunt.

37.  Infants with very severe RVOT stenosis and those with TOF
+ PA,with SaO2<70%, should have surgery within a few
weeks after birth.
 Infants with moderately severe stenosis and marked
cyanosis (SaO2 70–90%) should have corrective surgery by
2–4 months.
 Corrective surgery should be performed in all other infants
with tetralogy of Fallot by 6 months.
Contraindications for repair in early infancyPalliation initially
 LAD from RCA crossing infundibulum
 Severely hypoplastic PAs
 Pulmonary atresia

38. Palliative Procedures
Classic BT shunt[1945]…SCAPA on side opposite AA
Modified BT… esp in small infants <6 months…side to side
anastom with interposition graft of PTFE or Gore-Tex b/w SCA &
PA [on the same side of AA]
Waterston shunt : Side-side anastomosis of RPA to AA
Potts : Side - side anastomosis of LPA to DA
Waterston/Potts shunts : complications
 Excessive PBF  HF [20%] & PHTN
 Difficulty taking shunt down at time of correction
 Distortion of Rt/Lt PA ; Right/Left PA aneurysm

39. BT shunt-advantages :
(a)low incidence of problems from excess PBF
(b)No pericardial adhesions as pericardium is not entered
(c)Easy to close @ time of complete repair..ligating its distal part
just proximal to anastom with PA
(d)Less distortion of PAs
CENTRAL SHUNT :connecting a short tubular graft of Teflon or
GoreTex from the aorta to the MPA.
advantages vs other shunts:
 the size of the communication could be controlled by selecting a
tube with a diameter appropriate for the patient;
 branch PAs are not disturbed so that reconstruction is not
required at the time of corrective surgery.

40. CLASSIC BT shunt

41. POTTS SHUNT WATERSTON SHUNT

42. Interventional procedures :
In patients with severe annular hypoplasia….. palliation of
significant cyanosis by balloon valvuloplasty or RVOT stent
placement can be done… Improvement in antegrade flow
is thought to simultaneously enhance pulmonary arterial
growth by augmenting PBF
Balloon angioplasty of the pulmonary valve annulus is
preferable to a shunt procedure as it is
 less traumatic,
 it avoids a thoracotomy,
 reduces the likelihood of distortion of the pulmonary
arteries
Coil embolization of APCs ….Coiling of vessels that perfuse
pulmonary segments already supplied by pulmonary
arterial flow serves to reduce LV volume loading as well as
to eliminate runoff into the pulmonary arterial bed during

43. Surgery aims @
 relieving all possible sources of RVOTO;
 If possible, pulmonary valve function is preserved by avoiding a
transannular patch
 Closure of VSD (dacron patch)
 To relieve RVOTOpulmonary valvotomy, the insertion of an
outflow tract patch or a transannular patch are often required.
 Surgery during early infancy, when the pulmonary annulus is
markedly stenotic, frequently requires the insertion of a long
and wide transannular patch.
 Consequently, most patients acquire PR as a result of the repair.
PR may be well tolerated by many in the early postoperative
years, but in the long term chronic PR is associated with
reduced exercise capacity, RV dilatation, ventricular
arrhythmias, and sudden death.

44. PVR : Early PVR in selected patients results in beneficial
remodelling of the right ventricle
Optimal timing is critical for preserving RV function (not too
late) and avoiding the need for early re-operation (not too
early). Amelioration of RV function following PVR has to be
weighed against the risk of subsequent re-operation for
homograft failure.
Studies…RV end-diastolic volume may become a helpful
indicator for defining both a lower limit (150 mL/m2) and an
upper limit for re-intervention (200 mL/m2).[normal 60-
100]
CMR is the gold standard for evaluation of RV volumes and
quantification of the degree of PR & TR.

45. SURGERY in TOF contd…
VSD closure : Done thru’ RA approach whether or not a trans-
annular patch is used, as this approach allows to minimise the
length of the right ventriculotomy (length only necessary to
relieve the RVOT obstruction and not for the VSD exposure).
Efficacy of the RA approach ….
 Preserves the right ventricular function, …..
 Resultant PR after limited transannular patching is less severe
than that which occurs after transventricular repair
 Less incidence of ventricular/atrial arrhythmias is
 Easier to preserve the integrity & function of the tricuspid valve.
Concerns of right ventriculotomy (classical RV approach)
 Low cardiac output in the early postoperative period,
 a higher incidence of arrhythmias,
 Risk of late sudden death

46. In case of a major coronary artery crossing the RVOT…an
external conduit or homograft would be necessary;
Risk factors for early death after repair:
1) very young age
2) older age
3) severity of annular hypoplasia
4) small size of pulmonary arteries
5) need for transannular patch (debatable)
6) high peak RV to LV pressure ratio
7) previous palliative operations
8) multiple VSDs
9) co-existing cardiac anomalies

47. Advantages of early total correction
 Prevents cerebral hypoxia,cerebral embolism, abscess and
hematological changes
 Decrease RVPprevent persistent myocardial hypertrophy
and probably reduce the risk of fibrosis of the RV
 Providing adequate PBF will optimize the opportunity for
normal growth of the main and branch PAs…also normal
pulmonary circulation may be important for lung
development.
 Tendency for progressive hypertrophy of the RV
infundibular region is largely abolished by early repair.
 Early separation of MAPCAs from aorta reduces the risk of
PVOD

48. SURGERY IN TOF + PA :
 PA anatomy not favourable? ….Palliative procedures…
Central shunt vs reconstruction of RVOT using a
patch/conduit while leaving open the VSD
 If PA anatomy appears amenable to reconstruction,
procedures leading to complete repair are indicated.
Such procedures include RV outflow reconstruction for
inducement of central pulmonary artery growth using a
valved conduit / aortic or pulmonary homograft
 If there is a connection between RV & PT  correction can
be achieved with a patch reconstruction

49. PA anatomy assessment
1) McGoon ratio: (Diameter of RPA/DAo + Diameter of LPA/DAo)
 Normal 2.1
 Adequate for VSD closure 1.2
 Inadequate <0.8 for VSD closure
2) Nakata Index:(CSA of RPA + CSA of LPA)/BSA
 Normal value > 200 mm2/m2
> 150 mm2/m2 is adequate.
(Not usable preoperatively when MAPCAs are the major
source of PBF & one-stage unifocalization + full repair is
planned).

50. 3) Total Neo-Pulmonary Artery Index (TNPAI) = APC index +
Nakata Index
 APC index is the sum of CSA of all usable APCs/BSA
>250 - suitable for one-stage repair including VSD closure
(These pts. have low RV/LV pressure ratio postoperatively).
Critique of all these indices: These indices consider only the
size of proximal vessel and not consider the condition of
distal parts of the vessels (which may be stenosed).
Recently the value of all these has been questioned

51. MAPCAs : management : 2 options
1)Obliterate them by Sx ligation/coil embolisation
2)Surgical unifocalisation : if it is the sole supply to many
segments …..connecting all MAPCAs, as well as the small
native pulmonary arteries, to one source of blood flow from
the RV [ie to a central PA confluence or prosthetic PA
confluence]….. If performed early,it avoids the dvpt of PVOD
changes, as well as stenoses in the MAPCAs.
If the pulmonary vascular morphology and resistance are
such that adequate PBF can be accommodated…then RVP
after correction will be low enough to close the VSD.

52.  To assess whether this is likely, surgeons at the University
of California in San Francisco perfuse blood from the
perfusion system through the pulmonary artery at a rate of
2.5 L/min per m. If PA mean pressure is <25 mmHg, it is
considered safe to close the VSD. If it is not closed, the
patient is followed; the PVR may decrease over time,
allowing later closure. Also, if stenoses in pulmonary
vessels are noted, relief by balloon angioplasty, with
stenting if necessary, may permit RVP to fall and permit
closure of the defect.
 Post surgery if the RVP/LVP is >0.75….RVF may
result…avoid closure VSD / fenestrated patch closure

53. Hypoplastic PAs … intervene early …. Encourage them to
grow
 Reconstruction of RVOT with a patch or valveless conduit
 Placement of a central AP shunt
 If MPA,RPA & LPA are present, even though very small
(diameter 3 mm), they are capable of considerable
enlargement if blood flow through them is increased.
Creating an AP window early in infancy sufficient
enlargement of the pulmonary arterial tree to later perform
successful repair using the normal pulmonary arteries and a
unifocalization procedure can be avoided.

54. Dvpt of small pulmonary arteries
(A) Before central shunt was
performed, the Nakata index was
64 and the McGoon ratio was
0.82. (B) One hundred seventy-
four days after operation, the
Nakata index rose to 89 and the
McGoon ratio to 1.1.

55. Post Repair for TOF in general
Current surgical survival, even for symptomatic infants <3
months of age, is excellent.
Hospital and 1-month survival rates of 100% have been
reported.
Earlier age at repair (<1 year of age) did not adversely
affect the rate of reintervention; so primary repair should
be regarded as the preferred management strategy.
Twenty-year survival for hospital survivors, irrespective of
management strategy, was 98% for patients who have TOF
with PS and slightly lower for patients with PA, reflecting
the overall excellent long-term survival of these patients.

56. COURSE
In unrepaired TOF….increasing cyanosis due to progressive
infundibular obstruction. Beyond the neonatal period, they
are also at increasing risk for developing hypercyanotic
spells.
Older children with unrepaired or palliated TOF …
complications a/w chronic cyanosis ,polycythemiastroke,
brain abscess, and pigment gallstones.
Now rare …
‘infant repair is the rule’
PVOD in TOF : rare
 large surgical systemic-to-pulmonary artery shunts
 persisting large aortopulmonary collaterals

57. REPAIRED TOF :
Outcomes : excellent…recent reports…mortality <3%
Problems that may develop include
a)Residual VSDs
 Persistent defects at the patch margin or
 Previously unrecognized or underestimated additional defects in the
muscular septum.
 Partial patch dehiscence
b)Recurrent RVOTO :
 Muscle bundles obstruct the os infundibulum in 3%
 Nontransannular patches…annulus becomes restrictive as child grows
 Transannular patch…restriction at the distal insertion of the patch into the
branch pulmonary arteries.
 Stenosis owing to compression from an aneurysmal RVOT patch …. should
be approached surgically with revision of the patch and repair of the
proximal obstruction.
 may dvp additional sites of peripheral PS over time.

58. c)Progressive aortic root dilation &AR :
 Intrinsic dvptal abnormalities of aortic valve/root
 Palliative shunts or significant APCs left-to-right shunt
volume contribute to aortic dilation.
Progressive dilation of aorta correlate with longer time between
palliation & repair ; Pulmonary atresia ; right AA & male gender.
d) RV dilation;syst/diast dysfunction later RHF
 excess volume load from pulmonary regurgitation
 pressure load from outflow obstruction,
 Hypoxemic coronary perfusion,
 surgical incision, patch and scarring, and post–
cardiopulmonary bypass ischemia reperfusion injury—possibly
superimposed on tetralogy associated congenital abnormalities
of the myocardium.

59. e) LV dysfunction … consequence of adverse ventricular
interaction.
f) Rhythm disturb./SCD : Long-term mortality …. 3% to 6%.
A review of 125 adult patients with TOF suggested that a
greater degree of PR, a history of sustained VT, QRS duration
>180 ms, or LV dysfunction was a predictor of sudden death
g) Lower IQ
h) Life time increased risk for IE
i)Membranous subaortic stenosis …..may be seen years after
the initial repair in a few patients…may require surgical
excision.
j)Small coronary-to-RV fistulas, thought to relate to the
excision of muscle in the right ventricular outflow tract.

60. Post repair TOF + PA :
 Need for reoperation/ transcatheter balloon dilation and
stenting of an obstructed conduit in RV to PA conduit
surgery patients.
 Ongoing risk for recurrent peripheral PS…serial
catheterizations are indicated for ongoing pulmonary
artery rehabilitation
 higher risk for progressive aortic root dilation and AR

61. TOF + AVCD :
 risk for atrioventricular valve incompetence …. TR
right ventricular dilation, and dysfunction.

62. Congenital Absence of Pulmonary Valve Syndrome
 Chever in 1847
 incompletely formed, rudimentary pulmonary valve
that typically is both stenotic and regurgitant ;
aneurysmally dilated PA, and a large malaligned outlet
VSD.
 PDA is always absent….has been postulated as being
responsible for its pathogenesis and PA dysplasia.
 Other clinical features fairly typical in this disorder
include the common association of airway
abnormalities that may lead to severe respiratory
failure .
 The conal septal abnormalities and infundibular
obstruction, however, in distinction to typical tetralogy,
are less severe or absent, and much of the PS results

63.  Typically present in the neonatal period, and are diagnosed
based on the presence of their characteristic murmur and
the presence of cyanosis.
 A significant proportion of patients will present with
associated respiratory distress or frank respiratory failure,
often requiring mechanical ventilation.
 harsh to-and-fro murmur of PS followed by the diastolic
murmur of PR….sound of ’sawing wood’
 CXR…Massively dilated Pas ; Infundibular dilation project
leftward as a hump shaped shadow ; Pulmonary vascularity
is normal

64.  Some neonates present with severe bronchial obstruction
and require immediate tracheal intubation and mechanical
ventilation, followed by early surgical repair.
 Moderate resp obstruction … lying prone may help … by
relieving the anterior vascular compression of bronchi
 Mild or no airway obstruction may require no additional
support in the neonatal period and go on to elective repair
later in infancy.
 The surgical repair….. in addition to ventricular septal
defect closure and right ventricular outflow reconstruction,
involves reduction of the aneurysmal mediastinal
pulmonary arteries to relieve bronchial compression.

65. Outcome of TOF + APV depends largely on the severity of
airway disease.
Even after Sx,some pts continue to have bronchial
obstruction
 Residual airway hypoplasia and deformity
 Abnormally branching segmental pulmonary arteries
compressing the intraparenchymal bronchi
As these patients grow, however, pulmonary function tends
generally to improve as PAP fall and the maturing
tracheobronchial tree develops less compressible walls and
larger caliber.

66. THANK YOU