A 5-year-old child with Down syndrome presents with increasing breathlessness and cyanosis. Examination reveals a right ventricular heave, absent second heart sound, loud P2, and peripheral oxygen saturation of 78%. Previously documented VSD murmur is now absent. Which best explains this clinical scenario?

• A Spontaneous closure of VSD leading to right ventricular overload
• B Development of an additional pulmonary stenosis
• C Complete AV block causing reduced cardiac output
• D Eisenmenger syndrome with reversal of shunt through the VSD ✓

Explanation

This is classic Eisenmenger syndrome: previously acyanotic VSD that has progressively led to pulmonary arterial hypertension, equalisation of pressures, and reversal of shunt to right-to-left (Eisenmenger physiology). The disappearance of the murmur occurs because the pressure difference across the VSD diminishes as right-sided pressures equalise with systemic. Down syndrome infants are particularly prone to developing Eisenmenger syndrome earlier due to their predisposition to large AVSDs. Surgery at this stage is contraindicated.

Reference: Ghai Essential Pediatrics, 10th ed.

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Written and medically reviewed by the StethoPrep medical team.