What Is Cor Pulmonale? Understanding Causes, Symptoms, and Risk Factors

Cor pulmonale refers to a condition in which chronic lung or pulmonary vascular diseases lead to increased pressure in the pulmonary arteries—this elevated pressure, known as pulmonary hypertension, ultimately strains the right side of the heart. Over time, this strain causes the right ventricle to enlarge and weaken, resulting in right-sided heart failure. The disease typically develops gradually and is classified into acute and chronic forms, with the chronic type being far more common. In addition to symptoms related to underlying lung or chest wall disorders, patients may experience signs of impaired cardiac and respiratory function, including fatigue, shortness of breath, swelling in the legs, and fluid retention affecting multiple organs.

Primary Causes of Cor Pulmonale

Understanding the root causes of cor pulmonale is essential for early detection and effective management. Several underlying conditions can contribute to the development of pulmonary hypertension and subsequent right heart strain.

Chronic Bronchitis and Emphysema (COPD)

Chronic obstructive pulmonary disease (COPD), particularly chronic bronchitis and emphysema, is the most common cause of cor pulmonale. Persistent inflammation and airway obstruction in chronic bronchitis reduce oxygen exchange in the lungs. This leads to hypoxia, which triggers constriction of the pulmonary blood vessels. Over time, this vasoconstriction increases resistance in the pulmonary circulation, raising arterial pressure. Additionally, destruction of alveolar walls in emphysema reduces the surface area for gas exchange and diminishes the number of pulmonary capillaries, further contributing to pulmonary hypertension.

Alpha-1 Antitrypsin Deficiency

Alpha-1 antitrypsin deficiency is a genetic disorder that predisposes individuals to lung damage, particularly emphysema, even in non-smokers. This protein deficiency impairs the lungs' ability to protect elastic tissues from enzymatic breakdown. As lung tissue deteriorates, it mimics the effects of long-term smoking-related COPD, eventually leading to pulmonary hypertension and cor pulmonale. Early screening for this condition is recommended in patients with unexplained emphysema or a family history of early-onset lung disease.

Chest Wall and Thoracic Deformities

Structural abnormalities of the thorax can significantly impair lung expansion and function. Conditions such as severe kyphoscoliosis (spinal curvature), pectus excavatum (sunken chest), or ankylosing spondylitis can restrict lung volume and reduce respiratory efficiency. Similarly, rheumatoid arthritis may affect the joints of the chest wall, limiting rib movement and compromising ventilation. These mechanical limitations result in chronic hypoxia and secondary pulmonary hypertension, increasing the risk of cor pulmonale over time.

Pulmonary Vascular Diseases

Diseases directly affecting the pulmonary vasculature are another critical group of causes. Conditions like recurrent pulmonary embolism, where blood clots block small pulmonary arteries, increase vascular resistance and pressure. Chronic inflammation of the pulmonary arteries, as seen in pulmonary vasculitis, or the presence of multiple granulomas—as in diseases like sarcoidosis—can also obstruct blood flow and elevate pulmonary artery pressure. Over years, these vascular changes place excessive workload on the right ventricle, leading to its gradual failure.

In summary, cor pulmonale is not a standalone illness but rather a consequence of various progressive respiratory and vascular conditions. Recognizing the warning signs—such as worsening dyspnea, peripheral edema, and jugular venous distention—is crucial for timely diagnosis and intervention. Effective management focuses on treating the underlying lung disease, improving oxygenation, and reducing pulmonary artery pressure to prevent further cardiac deterioration.