The congenital cardiac abnormalities that are associated with cyanosis involve shunting of blood from the right side of the heart to the left side. These include the following cardiac abnormalities:

  • Tetralogy of Fallot
  • Pulmonary atresia with ventricular septal defect (VSD)
  • Transposition of the great vessels
  • Truncus arteriosus (associated VSD is always present)
  • Eisenmenger syndrome
  • Hypoplastic left heart syndrome

Those abnormalities manifesting in the neonatal period have a poor prognosis.


This is the commonest of the cyanotic group because of a slightly better prognosis in infancy, allowing more of them to survive longer.

Classically, Tetralogy of Fallot consists of;

  • Pulmonary stenosis
  • Ventricular septal defect
  • Dextroposition of the aorta
  • Right ventricular hypertrophy.

sSpecific Clinical Features

  • Cyanosis is a major feature. It may not be present at birth, but develops later during first year.
  • Other features include dyspnoea on exertion, to which the affected child responds by assuming a squatting position for a few minutes after such an exercise.
  • Affected children also tend to have paroxysmal hypercyanotic attacks often referred to as blue spells.
  • The pulse may be normal but a systolic thrill is felt along the left sternal border in 50% of cases.
  • Clubbing of fingers and toes occurs after a long time.

The following complications are associated with Tetralogy of Fallot:

  • Cerebral thrombosis due to polycythaemia,
  • Brain abscess (usually after 2 years of age) presenting with headache, fever, nausea and vomiting with or without seizures,
  • Bacterial endocarditis
  • Congestive heart failure.


  • Full blood count or haematocrit
  • CXR – Boot shaped heart oligaemic lung fields
  • Electrocardiogram
  • Echocardiogram
  • Blood culture if suspect endocarditis
  • CT scan if cerebral thrombosis or abscess is/are suspected


  • For children with blue spells, administer oxygen; child should be in kneechest position.
  • Prevent/correct dehydration in these children at all times.
  • Provide supportive therapy:
    • Venesection: Maintain haematocrit at 55–65% but avoid iron deficiency.
    • Intravenous or oral propranolol.
  • Refer all children to a specialist unit for definitive treatment by interventional closed repair or open heart surgery.