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Tetralogy of Fallot

It is a congenital disease of the heart that is composed of several abnormalities. It is the commonest cyanotic heart disease.

1. Pulmonary stenosis (tight pulmonary valve). This leads to obstruction to the right ventricular outflow.

2. Ventricular septal defect (VSD)

3. The aorta is overriding the septum (straddle).

4. Right ventricular enlargement.

Hemodynamically the heart is one chamber.

Clinical suspicion

The severity of obstruction to right ventricular outflow is of fundamental significance. When the obstruction is severe, the pulmonary blood flow is reduced markedly, and a large volume of deoxygenated systemic venous blood is shunted from right to left across the ventricular septal defect. Severe cyanosis (blue coloration of the skin) and erythrocytosis occur, and symptoms and sequelae of decreased oxygen are prominent. In many infants and children the obstruction is mild but progressive.

Radiologic examination characteristically reveals a normal-sized, boot-shaped heart (coeur en sabot) with prominence of the right ventricle and a concavity in the region of the pulmonary conus. The pulmonary vascular markings are typically diminished, and the aortic arch and knob may be on the right side.


1. Echocardiography: easily diagnosis the condition.


1. Total surgical correction

Patients are usually diagnosed and treated during childhood. Total surgical correction is ideal.

The size of the pulmonary arteries rather than the age or size of the infant or child is the most important determinant in establishing candidacy for primary repair. Pronounced thinning of the pulmonary arteries is a relative contraindication for an early corrective surgical procedure.

2. Shunt procedure

When pronounced thinning of the pulmonary artery is present, a palliative operation, such as creation of a systemic arterial-pulmonary arterial shunt, is carried out and is usually followed by complete correction, which can be carried out at a lower risk later in childhood.

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