Tricuspid atresia
Cyanotic CHD: absent tricuspid valve → hypoplastic RV (duct-dependent, single-ventricle pathway)
Overview
Absence of the tricuspid valve, so there is no inlet to the right ventricle (which is hypoplastic). Blood must shunt right-to-left at the atrium and depend on a VSD/duct for pulmonary flow — a CYANOTIC, duct-dependent single-ventricle lesion. Presents with neonatal cyanosis; managed with prostaglandin then staged single-ventricle (Fontan) surgery.
Recognise
- Neonatal cyanosis (duct-dependent pulmonary flow); LEFT axis deviation on ECG (a clue — unusual for a cyanotic neonate)
- Single ventricle physiology (hypoplastic RV); murmur of the associated VSD
- Duct-dependent → prostaglandin
Red flags
- Duct closure → worsening cyanosis → prostaglandin
- Single-ventricle pathway complications
Differentials & how to tell them apart
Investigations
Echocardiography (absent tricuspid valve, hypoplastic RV, shunts); ECG (LEFT axis deviation — characteristic).
Management
Prostaglandin (keep duct open) → staged single-ventricle (Fontan) surgery
- 1Confirm on echo (absent tricuspid valve, hypoplastic RV); ECG shows left axis deviation. Prostaglandin for duct-dependent flow; refer for staged single-ventricle surgery.Gate: Left axis deviation in a cyanotic neonate points to tricuspid atresia; it is duct-dependent → prostaglandin, then a staged Fontan pathway (not a biventricular repair)
- 2Staged palliation: BT shunt → bidirectional Glenn → Fontan; lifelong single-ventricle follow-up.
Key points
Cyanotic neonate + LEFT axis deviation on ECG = think tricuspid atresia (single ventricle). Duct-dependent → prostaglandin, then the Fontan pathway.
Monitor & prognosis
Saturations; single-ventricle staging.
Palliated (Fontan); not curative.
Source: RCPCH; paediatric cardiology