Overview
Cor pulmonale is the dysfunction of the right ventricle secondary to respiratory disease. This is due to the right ventricle working harder against pulmonary hypertension causing backflow of blood into the right atrium, the vena cava, and the systemic venous system.
Pulmonary hypertension may be due to:
- Chronic hypercapnia and respiratory acidosis leading to pulmonary vasoconstriction
- Damage to the lung parenchyma itself e.g. pulmonary fibrosis/COPD
- Increased blood viscosity due to the lung disease e.g. secondary polycythaemia
Most causes of cor pulmonale are chronic and progressive, however in the case of pulmonary embolisms, the presentation can be more acute (pulmonary embolisms can cause sudden pulmonary hypertension).
It may be helpful to read Heart Failure: An Overview to help with remembering and making sense of this chapter.
Epidemiology
- Most common cause in the developed world is COPD, which itself is mainly due to smoking
- Acute cor pulmonale is commonly due to a massive thromboembolism
Risk Factors
- COPD
- Smoking
- Pulmonary embolism
- Interstitial lung disease
- Primary pulmonary hypertension
Presentation
In early disease, the symptoms can be non-specific. Shortness of breath is usually the main presenting complaint, but this can be difficult to differentiate from concurrent respiratory disease. When a patient’s respiratory disease worsens, it may be due to cor pulmonale as well as the disease itself getting worse.
Other symptoms:
- Worsening tachypnoea
- Peripheral oedema
- Shortness of breath on exertion
- Syncope
- Chest pain
- Haemoptysis
- Hepatic congestion – this is a late-stage feature which has:
- Anorexia
- Jaundice
- Right-upper quadrant abdominal discomfort
Signs on Examination
- Cyanosis
- Plethora – patients look “ruddy” or “tanned” and this may be due to secondary polycythaemia
- Intercostal recessions
- Wheeze or crackles
- Pansystolic murmurs suggestive of tricuspid regurgitation
- 3rd or 4th heart sounds
- Distended neck veins
- Prominent jugular venous pressure (JVP)
- Peripheral oedema
- Hepatomegaly
Management
All patients
Management involves treating the underlying cause as well as possibly using long-term oxygen therapy.
Complications
- Exertional syncope
- Hypoxia
- Limited exercise tolerance
- Peripheral oedema
- Tricuspid regurgitation
- Liver cirrhosis
- Cardiac arrest
- Death
Prognosis
- The 5-year survival rate is around 50%
- The prognosis is poor but improves with smoking cessation and long-term oxygen therapy