Pulmonary hypertension in children — formative SAQs

SAQ 1 (10 marks) — The eight-year-old with exertional syncope and a loud second heart sound

Stem: An eight-year-old child is brought in after collapsing while running at school. Examination reveals a loud, palpable pulmonary component of the second heart sound, a right ventricular heave, and a soft pansystolic murmur at the lower left sternal edge. The echocardiogram estimates a raised pulmonary pressure. Outline the definition and classification, the investigation pathway, and the principles of management. ^{[1] [2]}

Model answer

Definition and classification (3 marks). Pulmonary hypertension is a mean pulmonary artery pressure above twenty millimetres of mercury confirmed at cardiac catheterisation, and pulmonary arterial hypertension adds a raised pulmonary vascular resistance — above three Wood units per square metre indexed in children — with a normal wedge pressure of fifteen or less. The WHO clinical classification sorts the disease into five groups: group one pulmonary arterial hypertension, group two left heart disease, group three lung disease or hypoxia, group four thromboembolic, and group five multifactorial. The group decides the cause and the therapy. ^{[3] [2]}

Investigation (3 marks). Echocardiography estimates the pressure from the tricuspid regurgitation velocity, assesses the right ventricle, and excludes or defines the congenital heart disease. Cardiac catheterisation is the gold standard and is performed in every child before targeted therapy, measuring the mean pulmonary artery pressure, the wedge pressure, the cardiac output, and the indexed resistance, and testing for vasoreactivity with inhaled nitric oxide. The bloods include the N-terminal pro-brain natriuretic peptide, the iron studies, and the genetic panel. ^{[7] [4]}

Management (4 marks). The therapy is risk-stratified. The vasoreactive idiopathic subset receives high-dose calcium channel blockers; the non-vasoreactive child receives combination therapy across the three pathways — a phosphodiesterase-5 inhibitor, an endothelin receptor antagonist, and a prostacyclin analogue. The right ventricle decides the prognosis, so a child in right ventricular failure is escalated to parenteral prostacyclin. The refractory child is escalated to atrial septostomy, the Potts shunt, and lung transplantation. ^{[1] [5]}