This document discusses long-term management of patients with repaired tetralogy of Fallot (rTOF). It notes that while surgical repair dramatically improves life expectancy, rTOF patients remain anatomically, physiologically, and electrophysiologically abnormal. Long-term follow up is needed as annual mortality risk increases over time. Key issues include progressive pulmonary regurgitation, right ventricular dysfunction, interactions between the right and left ventricles, arrhythmias and risk of sudden cardiac death, need for pulmonary valve replacement in some patients, and potential neurodevelopmental outcomes. Imaging modalities like echocardiography and cardiac MRI are important for assessment over time.

1. Long term management
of post TOF/ICR (rTOF)
Murtaza Kamal
Aug 20, 2019
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2. Scope of the talk
• Introduction
• Post op pathophysiology
• RV in rTOF
• RV-LV interactions
• Assessment of rTOF: Imaging modalities
• Aortic root in rTOF
• Arrhythmias and SCD risk
• Pulmonary valve replacement
• Neurodevelopmental outcomes
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3. Lets not forget …
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4. Introduction
Sx repair: Imp landmark: 1954 Lillhei n team
Complete repair: Dramatically alters life
expectancy; not curative: Anatomically,
physiologically, electro-physiologically abnormal
Long term survival: Not equal to general population:
Annual mortality risk increases by 0.1%per decade
rTOF: Disease needing follow up
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5. Natural n Unnatural h/o
TOF
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6. Abnormalities in rTOF
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7. Re-interventions in
rTOF
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8. PR
Key hemodynamically significant lesion: Progressive RV
dilatation+ Ventricular dysfunction
Increases with time—> RV volume overload (exacerbated by
distal PA stenosis)
Indications/ methods/ optimal timing of PV replacement:
Debatable
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9. Determinants of PR
Regurgitant orifice area
RV compliance
Diastolic pressure difference b/w MPA+ RV
Capacitance of PAs
Duration of diastole
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10. Determinants of PR
cont…
Torricelli principal:
PR Volume= ROA X C X DT X (P2-P1)
ROA: Regurgitation orifice area
C: Constant (empiric number)
DT: Diastolic time
P2-P1: Mean diastolic pressure
difference b/w MPA and RV
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11. PR pathophysiology
PR depends on:
Diastolic PA/RV gradient: Very little
PV orifice size
PA diastolic pressure depends on vessel recoil after
systole and transmitted pressure from LA
RV diastolic pressure depends on RV compliance
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12. Why is post op PR
progressive?
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13. RV post TOF repair
Pathophysiology of RV remodelling in response to altered hemodynamic
conditions after rTOF: Similar to response of LV to ch. volume overload
Differences with regard to:
Chamber geometry
Myofiber artitecture
Chamber contraction pattern
Coronary artery anatomy and flow dynamics
Disposition of conduction system
Dependency on LV size and function
Although RV function impacts LV function: Reverse much more
pronounced with 63%of RV pressure rise accounted for by LV contraction
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14. RV post TOF repair
cont…
Relief of RVOT obstruction involves:
Incision of infundibular free wall
Resection of obstructive muscle bundles
Disruption of PV with partial/complete excision
Placement of an outflow patch , often
extending to the plane of PV into MPA
Conduit: RV to PA
VSD patch closure (can impair TV function)
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15. rTOF issues
PR:
Akinesis/ Dyskinesis of RVOT
Outflow patch aneurysm
RV free wall fibrosis
Conduction delay
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16. Insights from CMR
Similar to LV function in severe chronic AR—> Once
compensatory mechanisms of RV fails, Mass: volume ratio
decreases, ES volume increases, EF decreases
Kurotobi et al: Demonstrated association b/w increase in RV
wall stress (afterload), decreased RV EF and symptoms in
rTOF
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17. rTOF: Factors
affecting RV mechanics
Size of outflow patch
RV fibrosis
Impaired RV diastolic function
LV dysfunction
Prolonged conduction time
Dyssynchrony of RV contraction
Older age of repair
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18. RV in rTOF
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19. RV-LV interaction after
TOF repair
RV+ LV functions in series: Similar net outputs in absence of
shunts
Bernheim: 1910
Bernheim effect: Alterations in size+ functions of LV—>
Adversely impact geometry+ function of RV eg: Sev MR—>
Displaces IVS into RV—> Elevates JVP
Reverse Bernheim effect: Alterations in size+ functions of
RV leads to LV dysfunction
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20. RV-LV interaction after
TOF repair cont…
Superficial spiralling layer of RV myofibers—> Continuous with
superficial layer of LV; Deep layer continuous through IVS
V-V interactions: Ventricles share myofibers, septum, coronary
blood flow, pericardial space
RV volume load—> Septum shifts towards left—> Leftward
shift of LV pressure- volume loop—> Reduced LV volumes
Progressive RV dysfunction—> LV function deteriorates
Ventricular dyssynchrony (Both intra+ inter ventricular):
Contributes to adverse RV-LV interactions
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21. Physiological factors
linking 2 ventricles…
Blood moved through lungs by RV—> LV preload+ CO
PS+ PR: Threatens LV preload+ CO
Change in shape/ size of RV—> LV also alters
Trans septal pressure gradient: Determines position of
ventricular septum at ED
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22. Pre op factors affecting
LV function in rTOF
Abnormal CA anatomy
Prolonged periods of deep cyanosis
LV volume overload: Palliative shunts
LVEF on CMR late after TOF repair influenced by:
RVEF
Duration of palliation pre repair
AR
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23. rTOF: How to follow
up?
History:
Effort intolerance, palpitation, neuro
developmental+ psychiatric evaluation
Examination:
Growth+ development, BP, JVP (Commonly raised-
Restrictive physiology, Prominent V waves if TR)
Cardiomegaly, RV outflow pulsations
Aortic enlargement
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24. ECG
Rhythm: Sinus/ CHB/ A flutter/ PCVs VT
Axis: RBBB/ QRS duration/ QRS fragmentation
Rt axis: Common, lt axis due to inlet VSD or post op
bifascicular block
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25. CXR
Heart size
Infundibular enlargement, RVOT aneurysm
RA enlargement in severe TR
Ascending aortic enlargement
Lung vascularity: Differential vascularity from PA
stenosis, collaterals
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26. ECHO assessment of
rTOF
Residua/ Sequelae/ complications
Residual VSD/ RVOTO
PA stenosis
PR
TR
RV/ LV function
Ascending aorta
Collaterals
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27. Doppler study
Non invasive hemodynamic information: Useful for
decision making
Assessment of PR severity
Diastolic flow reversal—> Severe PR, esp if in BPAs
PHT (<100msec)+ Jet annulus ratio (>1/3): Best
correlates with CMR severity
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28. 3D ECHO
Better assessment of PV morphology
Better characterisation of pulmonary flow
Underestimates RV volumes and EF
Low spacial+ temporal resolution
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29. CMR
Gold standard
Timing a major challenge in India: Availability and
cost
PR fraction
PR volume
RVEDV, RVESV
RV/LV Ratio
RVEF
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30. Late issues
Interventions: PA stenting, PV replacement,
Pacemaker implantation
Endocarditis
Contraception/ Pregnancy after rTOF
Neurodevelopmental outcomes
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31. Indications of PVR in patients with
rTOF/ similar physiology with
moderate- severe PR (RF≥25%)
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32. For symptomatic
patients…
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33. Special situations
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34. Benefits of PV
replacement
RV systolic pressure decreases
RVH decreases
RV dilatation decreases
TR decreases
RVEF increases
CI response to exercise increases
Exercise tolerance increases
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35. Life after PV
replacement
4.4/100 patient years need interventions
75%: Restenosis
15%: Endocarditis
2%: PR
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36. Dr. Phillip Bonhoeffer
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37. Melody PV
16+ 18 mm
22F Delivery sheath
Medtronic Inc.
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38. Edwards Sapien PV
23+26 mm
22 and 24 F del sh.
Edward’s life sciences
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39. 39

40. Arrhythmias after
rTOF
Bradyarrhythmias:
1% CHB after TOF repair—> May recover
Delayed recovery may predict late CHB+SCD
SV arrhythmias:
30% in late f/up
A fib, A flu, focal or re entrant recurrent
tachycardia—> All occur+ cause morbidity—>
CHF/ stroke/ VT/ reoperation/ mortality
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41. Electromechanical
interactions
Arrhythmias+ SCD: MCC of death post rTOF
Risk factors for SCD (1-5%):
Older age at sx repair
Moderate- severe PR
Sy+ Di dysfunction
Prolonged QRS interval (>180 msec)
CHB beyond 3rd POD
Repair via atriotomy
Male sex
Advanced NYHA class
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42. Electromechanical
interactions cont…
All pathophysiological mechanisms for arrhythmias present
Electrical instability:
Anatomical modifications following sx
Mechanical events like ventricular dilatation+ stretching
Abnormal fibrous tissues at different sites in RV/LV
Fibrofatty substitution around sx scar- Anatomical substrate
for re-entrant tachycardia
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43. Contraception/
pregnancy after rTOF
Early education to teenage girls
Recurrence risk/ males too
Mostly can choose from full range on contraception
Cautions with combined hormonal preparations in those with
significant vent dysfunction/ atrial arrhythmias- associated risks
of TE risks of oestrogen
Pregnancy generally well tolerated
Risks of pregnancy depends on severity of residual lesions, deg
of vent dysfunction, likelihood of developing arrhythmia
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44. IE
Rare after rTOF; but frequency increases after PV
replacement
Patients educated/ oral hygiene
Prophylaxis for those with conduits+ prosthetic
valves
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45. Aortic root post TOF
repair
Fetus with TOF: Normal aortic root diameter at
diagnosis—> Serial measurement—> Accelerated
growth (esp with severe RVOTO)
At birth: Absolute diameter of aorta increased
Increased volume load on developing aorta
?Histologic/ elastic abnormalities
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46. Aortic root dilatation
Can cause aortic insufficiency in adults: AV
replacement needed
Extremely rare: Aortic dissection
Studies revealed regression of aortic sinus years
after rTOF

47. Neurodevelopmental
outcomes
Long term f/up: Some impairment in cognitive+
motor development
All pts of rTOF: Appropriate developmental
behavioural surveillance+ screening
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48. 22q11.2 micro deletion
in TOF
Common association (8-15%)
May be diagnosed for 1st time in adulthood
Dyslexia, behavioural abnormalities+ psychiatric
disorders: Common
Genetic diagnosis allows early recognition+
treatment of non cardiac problem
AD: 50% risk to offspring
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49. So summing up with take home
message:
Current results of TOF repair
Child with TOF expected corrective surgery by 6 months: >96%
survival to hospital discharge
During childhood: 5% reoperation; 6% catheter interventions
PV replacement needed for 0.8%/year—>TOF-PA or TOF-APV
more likely
For a 30 yrs old rTOF: Annual risk of death 0.5%( Normal risk
0.15% males; 0.06% females)—> Risk increases by 0.1%/ decade
Increasing adverse outcomes with age: Related to
pathophysiology of rTOF
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50. Thank you…
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