27th July 2020

An infant is brought into the paediatric emergency department with worried parents

An infant is brought into the paediatric emergency department with worried parents. They describe spells wherein the baby has blue lips and becomes very pale and floppy. On examination the baby is small for his age and is breathing very rapidly. He has central cyanosis and upon auscultation a harsh systolic ejection murmur is heard. Aside from a diagnosis of trisomy 21, the infant has otherwise been well. 

For the scenario above, please select the SINGLE most likely diagnosis. Select ONE option from the list above.