Pulmonary arterial hypertension — Rapid

Synopsis

Recognise pulmonary arterial hypertension as a specialist haemodynamic diagnosis, distinguish it from pulmonary hypertension caused by left-heart, lung or thromboembolic disease, and escalate risk-directed care safely.

Pulmonary hypertension is a haemodynamic state with several causes; pulmonary arterial hypertension is the pre-capillary group after chronic thromboembolism, significant lung disease and left-heart disease have been excluded.
PAH may be idiopathic, heritable, drug-associated or linked to connective-tissue disease, congenital heart disease, portal hypertension or HIV.
Early symptoms are nonspecific: exertional breathlessness, fatigue, chest pressure and reduced exercise tolerance. Exertional presyncope or syncope is a high-risk feature.
ECG, chest radiograph and natriuretic peptide can support suspicion but may be normal early. Echocardiography estimates probability and assesses right-heart consequence.
Right-heart catheterisation at a designated centre is required before definitive classification and targeted treatment; an estimated echo pressure is not enough.
A V/Q scan is required to exclude chronic thromboembolic disease even when a CTPA is not reported to show emboli.
Treatment is based on multidimensional risk and commonly uses combination therapy across endothelin, nitric-oxide and prostacyclin pathways, initiated and monitored only by designated services.
Do not give PAH drugs empirically for pulmonary hypertension from left-heart or parenchymal lung disease; vasodilation can worsen pulmonary oedema or gas exchange.
Pregnancy carries major maternal risk in PAH and several therapies are teratogenic. Ask reproductive intentions early and arrange specialist contraception and preconception counselling.
NHS England updated its targeted-therapy commissioning policy in July 2026; eligibility and combinations must be checked live, with separate arrangements in devolved nations.

Key red flags

High-risk PAH

Presyncope or syncope, rapid symptom progression, rest symptoms, hypotension, cool peripheries, rising natriuretic peptide, severe right-ventricular dysfunction or pericardial effusion indicates urgent specialist review.

Decompensated right-heart failure

Peripheral oedema, ascites, hepatic congestion, oliguria, confusion and low output may coexist with clear lungs. Atrial arrhythmia or sepsis can precipitate rapid collapse.

Investigation priorities

ECG, chest radiograph and natriuretic peptideFirst step

Support pulmonary-hypertension suspicion, identify right-heart strain and provide prognostic baseline.

Management branches

SuspectFrom unexplained breathlessness to referral

Symptoms, high-risk condition or examination suggests pulmonary vascular disease.

Assess urgency, oxygenation, ECG, chest radiograph, natriuretic peptide and routine causes of breathlessness including anaemia and thyroid disease.
Obtain echocardiography and targeted lung assessment; do not diagnose PAH from symptoms or an echo estimate alone.
Arrange V/Q scanning when pulmonary hypertension is suspected so CTEPH is not missed.
Refer moderate or high echo probability, unexplained right-heart changes or a concerning high-risk phenotype to a designated PH centre.

Key medicines

PDE5 inhibitor such as sildenafilInitiated at a designated pulmonary-hypertension centre using the current commissioned regimen and BNF, with dose review for interactions and organ dysfunction.Do not combine with nitrates or riociguat. Watch hypotension, visual symptoms and CYP interactions; community initiation for unclassified pulmonary hypertension is unsafe.

Endothelin-receptor antagonistSpecialist selection and dosing follow the current NHS policy, product monograph and centre protocol; combinations are risk- and eligibility-dependent.Agents differ in hepatic, haemoglobin, oedema, interaction and pregnancy risks. Teratogenicity requires a documented pregnancy-prevention programme where relevant.

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