Pulmonary hypertension in children — branching viva

Branch 1 — Definition and classification

The candidate opens by defining pulmonary hypertension as a mean pulmonary artery pressure above twenty at cardiac catheterisation, with pulmonary arterial hypertension adding a raised resistance and a normal wedge pressure. They then name the five WHO groups and explain why congenital heart disease and bronchopulmonary dysplasia dominate the paediatric caseload. [3] [2]

Branch 2 — Diagnosis and the role of the catheter

The examiner probes why echocardiography is first-line but the catheter is the gold standard. The candidate explains that the echo estimates the pressure from the tricuspid regurgitation velocity and assesses the right ventricle, while the catheter confirms the diagnosis, measures the wedge pressure and the indexed resistance, and tests for vasoreactivity with inhaled nitric oxide. They stress that the wedge pressure is the safeguard against treating left heart disease. [1] [4]

Branch 3 — The three drug pathways and risk stratification

The candidate explains the three imbalanced endothelial pathways — nitric oxide and prostacyclin falling while endothelin rises — and the matching drugs: phosphodiesterase-5 inhibitors, prostacyclin analogues, and endothelin receptor antagonists. They describe the risk stratification into low, intermediate, and high risk, and why the high-risk child with right ventricular failure is escalated to parenteral prostacyclin. [5] [10]

Branch 4 — The Eisenmenger threshold

The examiner branches to the teenager with the late-repaired ventricular septal defect and the fixed resistance. The candidate explains that the catheter, not the echo, decides operability, that repairing a shunt above the threshold removes the pop-off and worsens the failure, and that the Eisenmenger physiology is irreversible. They outline the management with targeted therapy and the avoidance of pregnancy. [8] [5]

Branch 5 — Surgical escalation

The final branch covers the refractory child. The candidate describes the atrial septostomy as a pop-off that decompresses the right ventricle, the Potts shunt as reserved for the suprasystemic idiopathic form, and lung transplantation as the final option. They close on the principle that the right ventricle, not the pressure number, decides the prognosis. [4] [2]