Pulmonary Arterial Hypertension

Key points

• Defined as a resting mean pulmonary artery pressure of ≥ 25 mmHg · endothelin thought to play a key role in pathogenesis
• More common in females, typically presents aged 30-50 · risk factors: HIV, cocaine, anorexigens (e.g. fenfluramine) · around 10% inherited (autosomal dominant)
• Features: progressive exertional dyspnoea (classical) · exertional syncope · exertional chest pain · peripheral oedema · cyanosis · RV heave, loud P2, raised JVP with prominent 'a' waves, tricuspid regurgitation
• Acute vasodilator testing (IV epoprostenol or inhaled nitric oxide) is central: positive response (minority) → oral calcium channel blockers
• Negative response (vast majority): prostacyclin analogues (treprostinil, iloprost) · endothelin receptor antagonists (bosentan) · phosphodiesterase inhibitors (sildenafil) · progressive symptoms → heart-lung transplant · RV failure is the most common cause of death

Decision points in this pathway

• Positive response to acute vasodilator testing?

The full step-by-step algorithm, including what to do at each branch, opens in the app for approved members.