Cor pulmonale is an increase in bulk of the right ventricle of the heart, generally caused by chronic diseases or malfunction of the lungs. This condition can lead to heart failure.
Cor pulmonale, or pulmonary heart disease, occurs in 25% of patients with chronic obstructive pulmonary disease (COPD). In fact, about 85% of patients diagnosed with cor pulmonale have COPD. Chronic bronchitis and emphysema are types of COPD. High blood pressure in the blood vessels of the lungs (pulmonary hypertension ) causes the enlargement of the right ventricle. In addition to COPD, cor pulmonale may also be caused by lung diseases, such as cystic fibrosis, pulmonary embolism, and pneumoconiosis. Loss of lung tissue after lung surgery or certain chest-wall disturbances can produce cor pulmonale, as can neuromuscular diseases, such as muscular dystrophy. A large pulmonary thromboembolism (blood clot) may lead to acute cor pulmonale.
Causes and symptoms
Any respiratory disease or malfunction that affects the circulatory system of the lungs may lead to cor pulmonale. These circulatory changes cause the right ventricle to compensate for the extra work required to pump blood through the lungs. The right ventricle has thin walls and is crescent-shaped. The resulting pressure causes the right ventricle to dilate and bulge, eventually leading to its failure.
Cor pulmonale should be expected in any patient with COPD and other respiratory or neuromuscular diseases. Initial symptoms of cor pulmonale may actually reflect those of the underlying disease. These may include chronic coughing, wheezing, weakness, fatigue, and shortness of breath. Edema (abnormal buildup of fluid), weakness, and discomfort in the upper chest may be evident in cor pulmonale.
An electrocardiograph (EKG) will show signs such as frequent premature contractions in the atria or ventricles. Chest x rays may show enlargement of the right descending pulmonary artery. This sign, along with an enlarged main pulmonary artery, indicates pulmonary artery hypertension in patients with COPD. Magnetic resonance imaging (MRI) is often the preferred method of diagnosis for cor pulmonale because it can clearly show and measure volume of the pulmonary arteries. Other tests used to support a diagnosis of cor pulmonale may include arterial blood gas analysis, pulmonary function tests, and hematocrit.
Treatment of cor pulmonale is aimed at increasing a patient's exercise tolerance and improving oxygen levels of the arterial blood. Treatment is also aimed at the underlying condition that is producing cor pulmonale. Common treatments include antibiotics for respiratory infection; anticoagulants to reduce the risk of thromboembolism; and digitalis, oxygen, and phlebotomy to reduce red blood cell count. A low-salt diet and restricted fluids are often prescribed.
Co-management of the patient with cor pulmonale should be coordinated between the medical doctor and the alternative practitioner. The first step in treatment is to determine the cause of the condition and to evaluate all organ systems of the body. Dietary considerations, for example, a low-salt diet and reduced fluid intake aimed at reducing the edema associated with cor pulmonale, can be supportive aspects of treatment.
The prognosis for cor pulmonale is poor, particularly because it occurs late in the process of serious disease.
Cor pulmonale is best prevented by prevention of COPD and other irreversible diseases that lead to heart failure. Smoking cessation is critically important. Carefully following the recommended course of treatment for the underlying disease may help prevent cor pulmonale.
American Heart Association. 7320 Greenville Ave. Dallas, TX 75231. (214) 373-6300. 〈http://www.americanheart.org〉.
National Heart, Lung and Blood Institute. P.O. Box 30105, Bethesda, MD 20824-0105. (301) 251-1222. 〈http://www.nhlbi.nih.gov〉.
Ventricle— A cavity, as in the brain or heart. The right ventricle of the heart drives blood from the heart into the pulmonary artery, which supplies blood to the lungs.