QuestionSBA
QuestionChoice
This advice is usually given to parents of children suffering febrile convulsions.
10017280
e
If the episodes last for more than 5 minutes, call an ambulance
QuestionChoice
The presentation is consistent with Tetralogy of Fallot, which causes periods of cyanosis and may cause syncope commonly presenting a few months after birth.  This manoeuvre compresses the femoral arteries and increases peripheral vascular resistance, reducing the magnitude of the shunt.
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a
During the episode, pick the child up and bring his knees towards the chest
QuestionChoice
Tetralogy of Fallot does not resolve without surgical intervention.
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b
The episodes will self-resolve by the time he is 6 months old
QuestionChoice
This will not help.
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d
During the episode, do not move the child
QuestionChoice
This advice is usually given to parents of children who suffer breath holding attacks or reflex anoxic seixures.
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c
Avoid upsetting or triggering the child to prevent the episodes
QuestionComment
Surely surgery? 

38658
QuestionComment
ah yes tell the parents to cut the heart open
43516
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Ale
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Hallux Ketone
QuestionComment
I thought this was breath holding...
41619
QuestionComment
same here. tetralogy of fallot did not pop into my brain once :') 
44214
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Chronic Nightshift
QuestionComment
I think breath holding spells tend to happen a bit later on in life, toddler age onwards esp when they are upset/cry 
44716
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Probably Sepsis
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Botox Haemophilus
QuestionComment
surely you lay the child on their back rather than pick them up?
52818
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Rorskin Phimosis 
Concept
Chapter
# Summary
 

Tetralogy of Fallot is a cyanotic congenital heart defect characterised by a ventricular septal defect, overriding aorta, right ventricular outflow tract obstruction, and right ventricular hypertrophy. It typically presents antenatally or in infancy, with signs such as cyanosis and 'tet spells' (acute episodes of deepened cyanosis). Key investigations include echocardiography and cardiac catheterisation. Management is primarily surgical, involving the correction of the right ventricular outflow tract obstruction and closure of the ventricular septal defect.
 

# Definition
 

Tetralogy of Fallot (ToF) is a rare, cyanotic congenital cardiac condition. It consists of four key anatomical abnormalities:
 

 -  Ventricular septal defect (VSD)
 -  Overriding aorta: An aorta that is positioned over the right and left ventricles due to the presence of the VSD
 -  Right ventricular outflow tract obstruction (RVOTO): The primary **determinant of the severity of cyanosis**
 -  Right ventricular hypertrophy
 

# Epidemiology
 

Although relatively rare, affecting 1 in 3,600 infants, Tetralogy of Fallot is one of the most common congenital heart diseases, accounting for approximately 10% of all cases. It affects males and females equally. It may also occur alongside other chromosomal abnormalities such as Down syndrome or DiGeorge syndrome.
 

# Aetiology
 

The aetiology of the Tetralogy of Fallot remains largely unknown. However, genetic factors, maternal use of alcohol or drugs during pregnancy, diabetes mellitus, and maternal age over 40 years have been implicated. Individuals with congenital heart disease are at an increased risk of having children with congenital heart disease.
 
It is associated with many conditions:
 
 - 22Q11 microdeletion syndrome
 - Down's Syndrome
 - DiGeorge Syndrome
 - Foetal Alcohol Spectrum Disorder 
 

# Signs and Symptoms
 
ToF is commonly diagnosed due to:

- Abnormal foetal ultrasound scans
- Hypoxia at birth 
- Heart murmur on newborn exam 

This means many are diagnosed without the classical symptoms of Tetralogy of Fallot which include: 

- Cyanosis, which may be mild or severe depending on the degree of right ventricular outflow tract obstruction
- Detection of a heart murmur in the first few months of life
- Acute episodes of deepened cyanosis, known as 'tet spells', where there is a reversal of the shunt across the VSD, leading to a right-to-left shunt and exacerbated cyanosis
- Poor feeding and growth 
 

# Differential Diagnosis
 

When presented with a cyanotic infant, differentials may include:
 

 -  **Transposition of the Great Arteries**: Characterised by a loud, single second heart sound and absence of murmurs.
 -  **Tricuspid Atresia**: Features include cyanosis and a systolic murmur due to the associated ventricular septal defect or pulmonary stenosis.
 -  **Persistent Pulmonary Hypertension of the Newborn (PPHN)**: Symptoms are severe respiratory distress and cyanosis within *hours* of birth.
 

# Investigations
 
ToF may be diagnosed prenatally using foetal ultrasound and echocardiography. 

Key investigations for suspected Tetralogy of Fallot are:

- Oxygen saturation at birth 
- Echocardiography: The first-line investigation to confirm diagnosis and define anatomy
- Chest x-ray: May reveal a "boot-shaped" heart 

Further tests may include: 

- Hyper-oxygenation test: 
  - The neonate is given 100% FiO2 and then PaO2 is checked after 10 minutes. An increase of >25 mmHg and to a level of >100 mmHg would indicate a pulmonary cause, rather than. a cardiac cause, where the oxygen levels would not substantially increase. 
- Cardiac catheterisation: May be required to delineate the coronary artery anatomy and assess the degree of pulmonary vascular disease
 

# Management

Management depends on the severity of the cyanosis in addition to the severity of the defects. 

In neonates with severe hypoxia:

- Resuscitation following the neonatal resuscitation guideline should be followed. This would likely be supplemented by IV prostaglandin E1 to keep ductus arteriosus open. It can also be kept open through the insertion of a metal stent. 
- Some infants may need a synthetic shunt to be made connecting the aorta to the pulmonary artery. This is a temporary measure until full surgical correction can be achieved. 
-  Definitive treatment is corrective surgery at age 3-6 months. This may include: 
       - Correction of the right ventricular outflow tract obstruction with widening of the pulmonary valve 
       - Closure of the ventricular septal defect using a patch 
       - Surgical correction before 3 months is associated with increased post-operative complications and poorer outcomes. Repairing later than 12 months enables prolonged exposure to hypoxia and increased right ventricular hypertrophy, with an associated increased morbidity. 

 
In neonates with minimal symptoms: 

- Advice for the management of hypercyanotic "tet" spells is given to parents.
- Definitive management is surgical repair of VSD and correction of right ventricular outflow tract obstruction at age 3-6 months, as for symptomatic neonates. 
- A transcatheter stent with a balloon may be used to dilate the stenosed pulmonary artery. 


 
Management of hypercyanotic "tet" spells:

- Initial measures include positioning the infant on their back and flexing their knees. 
- Oxygen should be administered in hospitals. 
- Prophylactic use of propranolol is practised in some centres.
 
 
# Complications
 
Following the intervention, patients may still face complications from ToF such as:
 
 - Delayed neurodevelopment
 - Reduced exercise tolerance
 - Sustained ventricular tachycardia 
 - Aortic root dilatation 
 - Pulmonary valve regurgitation 
         - This may require subsequent surgical correction 
 
# Prognosis 
 
Without surgical intervention, the prognosis of ToF is poor with a less than 5% survival rate at 40 years. However, following surgical correction, survival rates at 30 years have increased up to an estimated 90%. 
 

# References
 
 [Information from Great Ormond Street Hospital](https://www.gosh.nhs.uk/conditions-and-treatments/conditions-we-treat/tetralogy-fallot)
 

 [Information from the British Heart Foundation](https://www.bhf.org.uk/informationsupport/publications/children-and-young-people/understanding-your-childs-heart---tetralogy-of-fallot)
 
 [Patient Info Fallot's Tetralogy](https://patient.info/doctor/fallots-tetralogy)
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In Tetralogy of Fallot, bringing the knees to the chest during a cyanotic episode increases systemic vascular resistance, alleviating hypoxia.
A 2-month-old boy is brought to hospital following periods of intense crying and irritability, followed by cyanosis and difficulty breathing. They report he has lost consciousness on two of these occasions. On auscultation, an ejection systolic murmur is heard.

Which of the following is the most appropriate advice to give his parents?
a