Cor Pulmonale

Cor pulmonale is a change in the size and function of the heart's right ventricle caused by disease of the lungs, airways, chest wall, breathing control, or lung blood vessels. The right ventricle pumps blood to the lungs to pick up oxygen. When pressure in the pulmonary arteries rises, the right ventricle has to pump harder. Over time, its wall thickens, its chamber enlarges, and its strength declines. Right heart problems caused by left heart disease or congenital heart defects are not considered cor pulmonale.

Why Lung Disease Strains the Heart

Low oxygen levels over a long period cause the small arteries in the lungs to narrow. In chronic lung disease, some of the lung tissue and its blood vessels are also damaged. Both raise the pressure in the pulmonary arteries, a condition covered on the Pulmonary Hypertension page. A common cause is chronic obstructive pulmonary disease (COPD), which is covered on the Chronic Obstructive Pulmonary Disease page. Other causes are pulmonary fibrosis, extensive scarring from past pulmonary TB, severe sleep apnea and obesity hypoventilation, deformities of the spine or chest wall, weakness of the breathing muscles, and long-standing clots in the pulmonary arteries, which are covered on the Chronic Thromboembolic Pulmonary Hypertension page.

Acute and Chronic Forms

Cor pulmonale usually develops slowly over many years. The acute form occurs when pressure in the pulmonary arteries rises suddenly, especially with a large pulmonary embolism, which is covered on the Pulmonary Embolism page. The acute form requires emergency care.

Symptoms Are Often Masked

At first, the symptoms of cor pulmonale resemble those of the underlying lung disease: shortness of breath during activity, coughing, and tiring easily. Signs that the right side of the heart is starting to weaken are swelling in both legs, an abdomen that feels full or swollen, rapid weight gain from fluid, and visibly bulging neck veins. Symptoms often worsen when the lung disease flares up, for example because of a respiratory infection.

Treatment Focuses on the Lungs

The key to treatment is treating the underlying lung disease and improving oxygen levels. In people with COPD whose oxygen level is low at rest, long-term oxygen therapy at home has been shown to prolong life expectancy. Medicines that remove fluid help reduce swelling, and breathing support devices used during sleep help people with sleep apnea. Care is provided jointly by lung and heart specialists, in line with the 2022 ESC/ERS guidelines for pulmonary hypertension and GOLD 2023 for COPD.

Your doctor asks about any history of lung disease, smoking, snoring and pauses in breathing during sleep, and any history of blood clots. The physical examination looks for signs of a strained right heart, such as bulging neck veins, an enlarged liver, and leg swelling. Oxygen levels are measured with a device on your finger and, if needed, with a blood gas analysis.

Echocardiography is the main test to assess the size and strength of the right ventricle and to estimate pulmonary artery pressure, although the images are sometimes less clear in severe lung disease. An ECG and a chest X-ray help show signs of right heart strain and the lung disease itself, while an NT-proBNP test assesses how heavily the heart is strained. Lung function tests and a chest CT assess the underlying lung disease. A ventilation-perfusion scan is used to look for long-standing clots in the lungs. Right heart catheterization, which measures pulmonary artery pressure directly, is done when its results will change treatment.

See a doctor if you have chronic lung disease and shortness of breath comes on more easily, your ability to walk declines, or swelling appears in your legs. Right heart symptoms are often masked by lung symptoms, so even small changes are worth reporting. Go to the emergency room right away if you have severe shortness of breath at rest, your lips become increasingly blue, or you faint.

• Swelling in both ankles or legs
• An abdomen that feels full or swollen
• Weight gain of more than 2 kg in 3 days
• Needing more oxygen at home than usual
• Loud snoring with pauses in breathing during sleep and frequent daytime sleepiness