Q A 3-yr old child presents with exertional dyspnoea since the age of one year. Examination reveals centarl cyanosis; systolic thrill & systolic murmur in the left 3rd & 4th parasternal space; and a single second heart sound. Which one of the following is not a correct statement regarding this case?
Congestive cardiac failure will rarely occur
Pulmonary plethora will be present
Cerebral thrombosis is a known complication
Right ventricular hypertrophy is characteristically present
The child is suffering from tetralogy of Fallot (TOF). The main clue for diagnosis is single second heart sound.
TOF consists of:
Pulmonary stenosis
Ventricular septal defect
Dextroposition of aorta with septal override.
Right ventricular hypertrophy.
Obstruction to pulmonary arterial blood flow is usually at both right ventricular infundibulum (Subpulmonic area) and the pulmonary valve.
VSD is usually large. Right to left shunt at ventricular level leads to systemic oxygen saturation of 82%.
Degree of right ventricular outflow obstruction determines the timing of onset of symptoms, severity of cyanosis and degree of right ventricular hypertrophy. In mild to moderate obstruction to right ventricular outflow, a balanced shunt is present across VSD, the patient may not be visibly cyanotic (acyanotic or pink tetralogy of Fallot).