3. Cyanotic Congenital Heart Defects
(Relative Frequency)
• Tetralogy of Fallot (10% of total Congenital Heart
Defects)
• Transposition of the Great Arteries - TGA (7% of total
Congenital Heart Defects)
• Rare Cyanotic Defects –
• Total Anomalous Pulmonary Venous Drainage
• Tricuspid Atresia
• Pulmonary Atresia
4. TOF
Tetralogy of Fallot
Pathophysiology, Clinical Features, Diagnosis
Complications, Management, Prognosis
Prof. Imran Iqbal
Fellowship in Pediatric Neurology (Australia)
Prof of Paediatrics (2003-2018)
Prof of Pediatrics Emeritus, CHICH
Prof of Pediatrics, CIMS
Multan, Pakistan
5. Dr. Etienne Fallot
Tetralogy of Fallot
Is named after
French physician
Etienne-Louis Arthur Fallot,
who accurately described the
4 anatomic abnormalities in
TOF in 1888
Dr. Etienne Fallot, 1850-1911
6. 4 Characteristics in TOF
• VSD
• Pulmonary stenosis
• Overriding aorta
• Right ventricular
hypertrophy
7. TOF – Four Components
• PS (Pulmonary Stenosis)
• Pulmonary valve narrowing results in less deoxygenated
blood transported to the lungs and more deoxygenated
blood passing through VSD to aorta to be circulated
throughout the body
• RVH (Right Ventricular Hypertrophy)
• Secondary to Pulmonary Stenosis resulting in increased
Right Ventricular Pressure
• Transposition of Aorta
• Aorta is displaced and overlies both ventricles
• VSD (Ventricular Septal Defect)
• Produces a shunt from Right to Left Ventricle with mixing of
deoxygenated blood with oxygenated blood
9. Clinical Scenario
• A 4 month old baby
presents with poor feeding.
Baby stops during mother
feeds and starts crying.
• On examination, bluish
tinge is noticed on lips and
face of baby.
• During auscultation, a heart
murmur is heard.
• Congenital Heart Disease is
suspected and further
investigations are
performed.
10. TOF - Clinical Features
• Cyanosis – may appear in neonatal life or later in
infancy
• Clubbing – appears in months to years
• Tachypnea – fast breathing
• Cardiac Examination
• Cardiac Apex beat in 4th intercostal space
• Right ventricular heave may be present
• Single P2 - second heart sound
• Ejection systolic murmur at Pulmonary area - left upper
sternal border
19. TOF - Complications
• Polycythemia – due to hypoxia
• Hyper-cyanotic Spell – paroxysm of tachypnea,
tachycardia, irritability, crying, lethargy & increased
cyanosis produced due to spasm of pulmonary
outflow tract and decreased pulmonary blood flow.
It requires immediate medical treatment.
• Cerebral thrombosis – due to Hypoxia
• Cerebral Abscess – Fever, Headache, Vomiting
• Failure to Thrive – Low weight, Short height
21. TOF – Medical Management
• Supportive Management:
• Adequate Hydration and Nutrition
• Oral Iron to prevent anemia
• Specific Management:
• Oral propranolol (dilates pulmonary tract and prevents
hypoxic spells)
• Management of complications:
• Management of Hyper-cyanotic spell
• Antibiotic prophylaxis against SBE
22. Management of Hyper-cyanotic spell
• Knee - chest position
• Oxygen
• Intravenous fluids
• IV Sedation (narcotic analgesics)
• IV Sodium bicarbonate to correct acidosis
• Propranalol (beta blocker)
23. TOF – Surgical Management
• Palliative Surgery – creation of a vascular shunt
between systemic and pulmonary circulation to
increase the pulmonary blood flow (performed in
severe cases)
• Blalock-Taussig shunt (B-T shunt) - is creation of a
vascular channel between Right Subclavian Artery
and Right Pulmonary Artery
• Corrective Surgery – surgical procedure to correct
the anatomical defects in TOF usually after infancy
24. Blalock-Taussig shunt
• Blalock-Taussig shunt
• Anastomotic shunt between
Right subclavian artery &
ipsilateral Pulmonary Artery
• Usually performed at 3 – 12
months of age in severe
cases
25. TOF – Corrective Surgery
• Patch closure of VSD &
widening of RV outflow
tract
• Timing of procedure
depends upon expertise
available
• Usually performed after
one year of age
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26. Prognosis
• Prognosis depends upon severity of disease and the
management available
• Infants with severe disease may die during a hypoxemic
spell
• Many untreated patients may not survive beyond 10
years of age
• Survival is better after first year of life
• Survival is good with adequate surgical management
29. Transposition of the Great Arteries
• Aorta arises from RV
• Pulmonary artery
arises from LV
• VSD in 20% of cases
30. TGA – Pathophysiology
• TGA patients need mixing of right of left heart
circulations in order to provide oxygenated blood
to body
• TGA with VSD or ASD has better survival
• TGA with intact septum (no VSD or ASD) remain
dependent on Patent Ductus Arteriosus, which
tends to close in neonatal life
35. TGA – Management
• In TGA with intact septum, Ductus Arteriosus needs
to be kept open to provide partially oxygenated
blood to body
• Newborn baby with TGA is given Prostaglandin
infusion to keep the Ductus Arteriosus open
• An artificial Atrial Septal Defect may need to be
created in the newborn by a catheter and balloon –
Balloon Atrial Septostomy
• Corrective surgery – Arterial Switch operation -
should be performed as soon as possible
