Cor Pulmonale

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | Patient Advice

Definition

Cor Pulmonale refers to right-sided heart failure caused by chronic pulmonary hypertension secondary to disorders of the lungs, pulmonary vasculature, chest wall, or respiratory control. It does not include right heart failure due to left-sided heart disease.

Aetiology

Cor pulmonale develops due to conditions that cause chronic pulmonary hypertension, including:

• Chronic Obstructive Pulmonary Disease (COPD): The most common cause.
• Interstitial Lung Diseases: E.g., idiopathic pulmonary fibrosis.
• Obstructive Sleep Apnoea: Causes intermittent hypoxia and pulmonary vasoconstriction.
• Chronic Thromboembolic Disease: Leads to increased pulmonary vascular resistance.
• Kyphoscoliosis or Obesity Hypoventilation Syndrome: Restrictive thoracic disorders.

Pathophysiology

The development of cor pulmonale involves:

• Chronic Hypoxia: Causes pulmonary vasoconstriction and increased vascular resistance.
• Pulmonary Hypertension: Leads to pressure overload on the right ventricle.
• Right Ventricular Hypertrophy: Adaptive response to chronic pressure overload.
• Right Heart Failure: Progression to decompensation, resulting in systemic venous congestion.

Risk Factors

Key risk factors include:

• Long-standing lung diseases such as COPD or interstitial lung disease.
• Obesity and obstructive sleep apnoea.
• Chronic thromboembolic disease.
• Occupational exposure to dust, chemicals, or fumes.
• Living at high altitudes.

Signs and Symptoms

Clinical features of cor pulmonale include:

• Dyspnoea: Progressive shortness of breath, initially on exertion.
• Fatigue: Related to reduced cardiac output.
• Peripheral Oedema: Swelling of the legs and ankles due to venous congestion.
• Jugular Venous Distension (JVD): Elevated central venous pressure.
• Hepatomegaly: Enlarged liver due to venous congestion.
• Cyanosis: Bluish discolouration of the skin and mucous membranes.

Investigations

Diagnostic tests and findings include:

• Clinical Examination: May reveal raised Jugular venous pressure(JVP), a right ventricular heave, or a loud P2 heart sound.
• Chest X-ray: Shows right ventricular enlargement or pulmonary artery prominence.
• Electrocardiogram (ECG):
  • Right axis deviation.
  • Right ventricular hypertrophy (RVH).
• Echocardiography: Confirms right ventricular hypertrophy or dilation and estimates pulmonary artery pressures.
• Arterial Blood Gas (ABG): May show hypoxia and hypercapnia.
• CT Pulmonary Angiography: To exclude chronic thromboembolic disease.

Management

1. Treat Underlying Lung Disease

• Optimise COPD Management: Use bronchodilators, inhaled corticosteroids, and smoking cessation.
• Oxygen Therapy: Long-term oxygen therapy for patients with chronic hypoxaemia (SpO₂ < 88%).
• Weight Management: For obesity hypoventilation syndrome.

2. Supportive Care

• Diuretics: E.g., furosemide to manage peripheral oedema and fluid overload.
• Fluid Restriction: To avoid volume overload.
• Anticoagulation: For chronic thromboembolic pulmonary hypertension.

3. Advanced Therapies

• Pulmonary Vasodilators: Considered in selected cases with pulmonary hypertension (e.g., phosphodiesterase inhibitors).
• Surgical Interventions: Rarely, lung transplantation may be an option in severe cases.

Patient Advice

Key advice includes:

• Adhere to treatment for underlying lung conditions, including inhalers and oxygen therapy.
• Avoid smoking and minimise exposure to respiratory irritants.
• Maintain a healthy weight and engage in light physical activity as tolerated.
• Attend regular follow-ups to monitor disease progression and adjust management.
• Recognise and report worsening symptoms, such as increased breathlessness or swelling.