Makindo Medical Notes

🫁 Shunts will always try to shift blood to the low-pressure pulmonary circulation, but this eventually causes pulmonary hypertension. PH is defined by a mean pulmonary artery pressure > 25 mmHg at rest (or > 30 mmHg on exercise).

📖 About

• 💔 Pulmonary hypertension (PH) / cor pulmonale = right heart failure due to lung disease, often linked to chronic hypoxia (e.g., COPD).
• 🫀 Cor pulmonale = secondary PH due to hypoxic vasoconstriction and vascular remodelling, most common in emphysema.
• 📊 Defined as chronic elevation of pulmonary artery pressure (> 25 mmHg at rest, > 30 mmHg on exercise; some use systolic PA pressure > 40 mmHg).

📌 Classification

• Group 1: Pulmonary arterial hypertension
• Group 2: Pulmonary venous hypertension (e.g., LV failure, mitral disease)
• Group 3: PH due to respiratory disease / hypoxia
• Group 4: PH due to thromboembolic disease
• Group 5: PH due to pulmonary vasculature disorders (miscellaneous)

🧬 Pathophysiology

• ⬆️ LV filling pressure with normal PVR (e.g., mitral stenosis)
• 🌐 Pulmonary vascular disease with elevated PVR (e.g., pulmonary embolism, CTEPH)
• 🌫️ Parenchymal lung disease with elevated PVR (e.g., diffuse lung fibrosis, COPD)
• 🌀 Combination of these mechanisms → sustained pulmonary hypertension

⚠️ Causes

• 🚬 COPD, emphysema
• 🌫️ Interstitial lung disease (e.g., IPF)
• 🫀 Idiopathic pulmonary hypertension
• 🩸 Multiple pulmonary emboli (CTEPH)
• 🫁 Congenital heart disease with Eisenmenger’s syndrome
• 💔 Mitral stenosis, LV failure, LA myxoma
• 🧬 Neuromuscular weakness (MND, muscular dystrophy)
• 🦴 Chest wall deformities (kyphoscoliosis)
• 🧪 Drugs (e.g., dexfenfluramine)
• 🧬 Sickle cell disease
• ⛰️ Living at high altitude (chronic hypoxia)

👀 Clinical Features

• 🏃 Progressive exertional dyspnoea (esp. in COPD)
• 🫀 Right heart strain → raised JVP, tricuspid regurgitation, loud P2, parasternal heave
• 💧 Fluid overload → peripheral oedema, ankle swelling, ascites (advanced)

🔎 Investigations

• 🩸 FBC: Polycythaemia from chronic hypoxia
• 🧪 U&E, LFTs, CRP: Baseline + comorbidity assessment
• 📉 ECG: RVH, RBBB, P pulmonale, RV strain
• 💨 ABG: Hypoxia ± hypercapnia (late)
• 🩻 CXR: Prominent pulmonary arteries, pruning of peripheral vessels
• 🫀 Echo: RV dilatation, TR, estimated PA pressures
• 🖥️ CT-PA: Evaluate for CTEPH, pulmonary emboli

💊 Management

• 💨 Long-term oxygen therapy (LTOT): Reduces hypoxaemia and pulmonary vasoconstriction; improves survival in COPD with PaO₂ ≤ 7.3 kPa.
• 💊 Anticoagulation: Indicated in recurrent emboli / atrial fibrillation / CTEPH.
• 💧 Diuretics: For oedema & ascites (caution: avoid over-diuresis → ↓ RV filling).
• 💊 Vasodilators / CCBs: Reserved for select idiopathic PH cases (specialist care).
• 🌬️ Treat underlying lung disease: COPD, ILD, etc.
• 🫁 Transplant: Consider in advanced refractory disease.
• 🌷 Palliative care: Symptom control (breathlessness, oedema, anxiety).

3 Clinical Cases — Secondary Pulmonary Hypertension 💓🫁

• Case 1 — Left heart disease (post-capillary PH) ❤️: A 72-year-old man with long-standing hypertension and heart failure with preserved ejection fraction (HFpEF) presents with worsening exertional dyspnoea and ankle swelling. Echo shows concentric LVH, diastolic dysfunction, dilated left atrium, and estimated pulmonary artery systolic pressure of 55 mmHg. Teaching: Left-sided heart disease is the most common cause of secondary PH. Chronically raised left atrial pressure is transmitted backward to the pulmonary vasculature → pulmonary venous hypertension.
• Case 2 — Chronic lung disease / hypoxia 🌫️: A 66-year-old ex-miner with advanced COPD reports worsening breathlessness, reduced exercise tolerance, and peripheral oedema. Oxygen saturation 86% on air. Echo shows dilated RV with moderate pulmonary hypertension. Teaching: Chronic hypoxaemia causes pulmonary vasoconstriction and vascular remodelling, leading to “cor pulmonale.” Long-term oxygen therapy improves survival in these patients.
• Case 3 — Chronic thromboembolic pulmonary hypertension (CTEPH) 🩸: A 59-year-old woman with a history of recurrent unprovoked DVTs and a pulmonary embolism 18 months ago reports progressive dyspnoea. V/Q scan shows multiple segmental perfusion defects; CT pulmonary angiography confirms organised chronic thrombus. Teaching: CTEPH is an important cause of secondary PH. It is potentially curable with pulmonary endarterectomy or balloon angioplasty, and all patients should be referred to a specialist centre.