Pulmonary hypertension is a rare lung disorder characterized by increased pressure in the pulmonary artery. The pulmonary artery carries oxygen-poor blood from the lower chamber on the right side of the heart (right ventricle) to the lungs where it picks up oxygen.
Pulmonary hypertension is present when the blood pressure in the circulation of the lungs is measured at greater than 25 mm of mercury (Hg) at rest or 30 mm Hg during exercise. Pulmonary hypertension can be either primary or secondary:
Regardless of whether pulmonary hypertension is primary or secondary, the disorder results in thickening of the pulmonary arteries and narrowing of these blood vessels. In response, the right side of the heart works harder to move the blood through these arteries and it becomes enlarged. Eventually overworking the right side of the heart may lead to right-sided heart failure, resulting in death.
While the cause of primary pulmonary hypertension is uncertain, researchers think that in most people who develop the disease, the blood vessels are sensitive to certain factors that cause them to narrow. Diet suppressants, cocaine, and pregnancy are some of the factors that are thought to trigger constriction or narrowing of the pulmonary artery. In about 6–10% of cases, primary pulmonary hypertension is inherited.
Secondary pulmonary hypertension can be associated with breathing disorders such as emphysema and bronchitis, or diseases such as scleroderma, systemic lupus erythematosus (SLE) or congenital heart disease involving heart valves, and pulmonary thromboembolism.
Symptoms of pulmonary hypertension include shortness of breath with minimal exertion, general fatigue, dizziness, and fainting. Swelling of the ankles, bluish lips and skin, and chest pain are among other symptoms of the disease.
Pulmonary hypertension is rarely detected during routine physical examinations and, therefore, often progresses to later stages before being diagnosed. In addition to listening to heart sounds with a stethoscope, physicians also use electrocardiogram, pulmonary function tests, perfusion lung scan, and/or right-heart cardiac catheterization to diagnose pulmonary hypertension.
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Author Info: Lorraine Steefel RN, The Gale Group Inc., Gale, Detroit, Gale Encyclopedia of Medicine, 2002 |