Cor pulmonale is also known as pulmonary (=to do with lungs) hypertension (=high pressure) or right heart failure. It results in enlargement of the right side of the heart (which pumps blood through the blocked lungs), and increased blood pressure in the lungs. It is primarily a sign of obstructed blood circulation through the lungs, and not heart disease, although congenital heart disease and left heart disease must be excluded.
Lungs damaged by emphysema, smoking, inhaled coal dust or asbestos, recurrent lung infections or a number of rarer lung diseases may be so abnormal that the blood has difficulty in passing through them. The right side of the heart must work harder to force the blood through the damaged lungs, which causes a significant rise in the blood pressure in the right heart and lungs. This causes further damage to arteries and worsens the disease. The heart muscle thickens and enlarges, and because of the lung damage, inadequate oxygen enters the blood, which further compounds the problem.
Patients have a cough that produces clear or bloodstained phlegm, a wheeze, shortness of breath with any exertion and general weakness. In advanced cases the ankles may be swollen, nausea and indigestion may occur, and the liver enlarges. Patients are more susceptible to lung infections such as bronchitis and pneumonia.
The diagnosis can be made by a chest X-ray and an electrocardiogram (ECG). Other investigations include cardiac catheterisation (passing a tube through a vein into the heart to measure the blood pressure), echocardiography and angiography.
Medication (eg. bosentan, ambrisentan) can be prescribed to strengthen the heart, open the lungs and cure any lung infection. Physiotherapy can help drain phlegm from the lungs, and oxygen may be used to relieve the shortness of breath.
Unfortunately, no cure is possible and patients steadily deteriorate over many years to eventually die from heart attacks, pneumonia or other complications of the disease.