⚠️ Pulmonary hypertension (PH) is a progressive condition of raised pulmonary artery pressures leading to right heart strain and failure. Early recognition is crucial as treatment can slow progression but rarely reverses disease.

📖 About

Defined as mean pulmonary artery pressure (mPAP) > 25 mmHg at rest, > 30 mmHg with exercise.
🟣 Primary Pulmonary Hypertension (PPH) = no identifiable cause.
Rare disease: ~2 cases per million per year.

⚙️ Aetiology & Pathophysiology

⬆️ Pulmonary vascular resistance → sustained pressure overload on right ventricle.
Flow equal in systemic & pulmonary circuits (no shunts), but pulmonary bed is normally much larger.
Imbalance: vasoconstriction, endothelial dysfunction, fibrosis & thrombosis → progressive narrowing.

🔗 Associations

💊 Appetite suppressants (e.g. fenfluramine).
🔥 Vasculitis affecting pulmonary vessels.
🤲 Connective tissue diseases (esp. systemic sclerosis).

🧬 Genetics

Familial PH: autosomal dominant, often BMPR2 or ALK1 mutations.

📂 Classification

🟣 Pulmonary arterial hypertension (PAH).
🔵 Pulmonary venous hypertension (often left heart disease).
🟤 PH with respiratory disease or hypoxia (e.g. COPD, OSA, ILD).
🟠 PH due to chronic thromboembolic disease (CTEPH).
🟢 PH due to miscellaneous pulmonary vascular disorders.

🩺 Clinical

Most common in 👩 women aged 20–30 years.
Symptoms: progressive exertional breathlessness, fatigue.
Signs: loud P2 🔊, RV heave, right-sided S3.
JVP: prominent "a" & "v" waves; TR murmur (pansystolic).
Pulmonary flow murmur may be heard.

🔍 Investigations

🧪 Bloods: FBC → polycythaemia; U&E for renal function.
📈 ECG: RVH, RBBB, P pulmonale.
📸 CXR: Enlarged pulmonary arteries, peripheral pruning.
🫀 Echo: RV dilatation, TR, pressure estimates.
CT-PA: Rule out chronic thromboembolic disease.
Pathology: Plexiform lesions, in situ thrombosis.

💊 Management

Oxygen for hypoxia, diuretics for oedema, anticoagulation, digoxin (supportive).
🟢 Calcium channel blockers (high-dose nifedipine/amlodipine) if vasoreactive subset.
🟣 Prostacyclin analogues (Iloprost infusion/nebulised) for advanced disease (NYHA III/IV).
🔴 Endothelin receptor antagonists (e.g. Bosentan).
🟡 PDE-5 inhibitors (Sildenafil) → nitric oxide–like vasodilation.
⚪ Atrial septostomy (palliative, under evaluation).
🫁 Lung / heart-lung transplantation for end-stage cases.
👩‍🍼 Contraception strongly advised – pregnancy is contraindicated.
Advice: avoid high altitude ✈️, restrict strenuous exercise.
🩸 Venesection if severe polycythaemia (symptomatic hyperviscosity).

📚 References

Cases - Primary Pulmonary Hypertension (Pulmonary Arterial Hypertension, PAH)

Case 1 - Young woman with exertional symptoms 👩‍🦰: A 27-year-old previously healthy woman presents with 6 months of progressive exertional dyspnoea and fatigue. She has near-syncope on climbing stairs. Exam: loud P2, right ventricular heave, peripheral oedema. Echocardiogram: dilated RV, estimated pulmonary artery systolic pressure 70 mmHg. Right heart catheterisation confirms raised mean PAP. Diagnosis: idiopathic PAH. Managed with endothelin receptor antagonists and pulmonary vasodilators.
Case 2 - Family history 🧬: A 33-year-old man with two relatives who died young of unexplained right heart failure presents with progressive breathlessness. Exam: raised JVP, hepatomegaly, ankle oedema. BNP elevated. CT pulmonary angiography normal (no thromboembolism). Genetic testing: BMPR2 mutation. Diagnosis: heritable PAH. Managed with specialist pulmonary hypertension unit input, prostacyclin analogues, and anticoagulation.
Case 3 - Advanced disease with syncope ⚠️: A 42-year-old woman presents with recurrent syncope, chest pain, and worsening dyspnoea. Exam: cyanosis, loud P2, pansystolic murmur of tricuspid regurgitation. Echo: severe PAH with right atrial/ventricular enlargement. She is in right heart failure. Diagnosis: advanced primary PAH. Managed with oxygen, intravenous prostacyclin, and consideration of lung transplantation.

Teaching Point 🩺: Primary (idiopathic or heritable) pulmonary arterial hypertension is a rare, progressive disease of the pulmonary arterioles causing elevated pulmonary artery pressures and right heart failure. Presents with dyspnoea, syncope, chest pain, and signs of right-sided overload. Diagnosis confirmed with right heart catheterisation. Treatment includes endothelin receptor antagonists, phosphodiesterase-5 inhibitors, prostacyclin analogues, and transplant in advanced cases.

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Primary Pulmonary Hypertension