Truncus arteriosus and single-ventricle physiology — branching viva

Branch one — the cyanotic infant in heart failure

The examiner opens with a four-week-old who was mildly dusky from birth and now has tachypnoea, sweating on feeds, bounding pulses, a wide pulse pressure and a single second heart sound. Take the candidate through the bedside reasoning to truncus arteriosus, the falling-pulmonary-vascular-resistance mechanism that turns cyanosis into heart failure, and the complete neonatal repair. Probe why every such infant needs 22q11.2 testing. [3] [5]

Branch two — the interstage infant

The examiner moves to a four-month-old between the Norwood and the Glenn whose home saturation has dropped from the eighties into the seventies. Explore why this window carries the highest mortality, what an interstage home-monitoring programme contains, and the immediate management of any deterioration. [12]

Branch three — the Fontan survivor

The examiner closes with a sixteen-year-old Fontan patient with leg swelling and palpitations. Ask about the long-term complications of the Fontan circulation — the four pillars of morbidity — and the role of the general paediatrician in sustaining lifelong follow-up, neurodevelopmental surveillance and transition to adult congenital heart disease services. [10]