Tetralogy Of Fallot - Long Case Study

Presenting Complains:
- Breathlessness for … months
- Bluish discoloration of the lips and fingers during exertion for … months
- Weakness for … months
- Palpitation for … months
- Chest pain for … months
- Cough for … months.

History of Presenting Complains: According to the patient’s statement, she has been suffering from
breathlessness since her childhood. Her breathlessness was less marked in earlier stage, only felt
during moderate to severe activity. But for the last few months, it is progressively increasing, even
during mild exertion. There is no seasonal variation of breathlessness and it is not associated with
exposure to dust, pollen or fume. There is no history suggestive of paroxysmal nocturnal dyspnea or
orthopnea. The patient also noticed bluish discoloration of skin, finger nail, toes and lips for the last
… months, which is more marked during exercise and less by taking squatting position. She also
experiences diffuse chest pain, usually following any activity or after eating, which radiates to left
shoulder and subsides after taking rest. She also complains of palpitation, weakness and occasional
dry cough. Her bowel and bladder habits are normal. Her mother mentioned that the patient used to
become bluish and breathless while feeding or crying during the first few years of life.

On General Physical Examination:
- The patient is emaciated and short in stature
- Dyspneic
- Central cyanosis (involving tongue, lips, fingers and toes) is present
- There is generalized clubbing (involving all fingers and toes)
- Pulse: 112/min, low volume, regular in rhythm and normal character
- BP: 100/60 mm Hg
- Temperature: 98ºF
- Respiratory rate: 28/min
- No anemia, leukonychia, koilonychia, edema, jaundice, lymphadenopathy or thyromegaly

Cardiovascular system
- Pulse: 112/min, low volume, regular in rhythm and normal character
- BP: 100/60 mm Hg
- JVP: prominent “a” wave
- Visible cardiac impulse in apical and epigastric region
- Apex beat—palpable in the left … intercostal space, … cm from midline, normal in character
- Left parasternal lift and epigastric pulsation—present
- Systolic thrill—present in pulmonary area.
- First heart sound—normal in all the areas
- Second heart sound—P2 is soft (or absent) in pulmonary area, A2 is normal
- There is a harsh ejection systolic murmur in the pulmonary area, which radiates to the neck, more
on inspiration.

Examination of other systems reveals normal findings.

What is the Provisional Diagnosis? 
Tetralogy Of Fallot (TOF)

Mention some cyanotic congenital heart disease.
As follows:

• Tricuspid atresia
• Transposition of great vessels
• Pulmonary atresia
• Ebstein’s anomaly.

What investigations are done in TOF?
As follows:

• Chest x-ray- shows boot-shaped heart, pulmonary conus is concave (small pulmonary artery), right ventricle enlarged (prominent elevated apex), oligemic lung, right-sided aortic arch in 25% cases.
• 2D echocardiography and color Doppler (diagnostic—it shows that the aorta is not continuous with the anterior ventricular septum).
• Other investigations: ECG (RVH), cardiac catheterization in some cases.

What is tetralogy of Fallot?

It is a cyanotic congenital heart disease consisting of:

• Right ventricular hypertrophy.
• VSD (perimembranous, usually large, subaortic).
• Right ventricular outflow obstruction—this may be subvalvular (infundibular), valvular or supravalvular. The most common obstruction is subvalvular, either alone (50%) or in combination with pulmonary stenosis (25%).
• Overriding and dextro-position of aorta (aortic origin—2/3rd from left ventricle and 1/3rd from right ventricle).

What are the cardinal features of TOF?

As follows:

• Child with growth retardation
• Clubbing
• Cyanosis
• Pulmonary ejection systolic murmur
• History of cyanotic spells during exercise (relieved by squatting).

How the patient usually presents?

As follows:

Young children usually present with cyanotic spell (Fallot’s spell) during exertion, feeding or

crying. They may become apneic and unconscious.

In older children, Fallot’s spells are uncommon but cyanosis becomes increasingly apparent with

clubbing and polycythemia. There may be Fallot’s sign.

Other features include:

• Shortness of breath on exertion, easy fatiguability.
• Growth retardation.
• Syncope, seizure, cerebrovascular events or even sudden death.

Why syncope occurs in TOF?

During exercise, there is increased pulmonary resistance and reduced systemic vascular resistance.

So, there is increased right to left shunt and admixture of blood of right and left ventricles. As a result, there is reduced cerebral oxygenation, causing syncope.

Why there is cyanosis in TOF?

Because of the overriding of aorta, there is admixture of blood of right and left ventricles. Cyanosis

is absent in newborn or acyanotic Fallot’s.

When is cyanosis aggravated and Why?

 Cyanosis is aggravated during exercise and is called cyanotic spell or Fallot’s spell. It is also

aggravated during feeding or crying. Cyanosis is reduced by squatting. Child may be apneic and

unconscious. Syncope, seizure, cerebrovascular accident (CVA) or sudden death may occur. Fallot’s

spell is uncommon in older children. Cyanotic spell is due to increased obstruction, as a result of

increased sympathetic stimulation that occurs during exercise, feeding and crying.

How squatting relieves cyanosis?

In squatting position, abdominal aorta and femoral artery are compressed. So, there is increased

arterial resistance, which increases the pressure in the left ventricle, leading to diminished right to

left shunt through VSD and increased flow through pulmonary artery. This reduces admixture of blood from right and left ventricles and relieves cyanosis.

What are the complications of tetralogy of Fallot?

As follows:

• Infective endocarditis (common)
• Paradoxical emboli
• Cerebral abscess (10% cases)
• Polycythemia (due to hypoxemia, and may lead to cerebrovascular accident and myocardial infarction)
• Coagulation abnormality.

How to assess the severity of TOF?

As follows:

- Mild case—loud and prolonged murmur

- Severe case—murmur reduced or absent.

What is pentalogy of Fallot?

When TOF is associated with ASD.

What is triology of Fallot?

ASD with PS with RVH.

Why there is no murmur of VSD in TOF?

Because VSD is large and there is equal pressure in right and left ventricles.

What is acyanotic Fallot?

When the TOF is associated with infundibular pulmonary stenosis. Outflow obstruction is mild

and there is no cyanosis.

How to treat TOF?

As follows:

• Surgical correction is the definitive treatment, ideally should be done prior to 5 years of age. Surgical relieve of pulmonary stenosis and closure of VSD is done.
• If pulmonary artery is hypoplastic or anatomy is unfavorable, then temporarily palliative surgery called Blalock-Taussig shunt is performed. Corrective surgery is done later on.
• Prophylactic antibiotic to prevent infective endocarditis.

How to treat during cyanotic spell?

As follows:

• Knee-chest position of child
• High concentration of O2
• Injection morphine or diamorphine (it relaxes right ventricular outflow obstruction)
• b-blocker may be used
• If medical therapy fails, emergency surgical shunt may be considered.

What is the prognosis of TOF?

 Prognosis is good after surgery, especially if operation is done in childhood. Re-stenosis, recurrence

of septal defect and rhythm disorder may occur after surgery. So, regular follow-up is required in

every case.