pulmonary hypertension (redirected from Pulmonary Arterial Hypertension)

Pulmonary Hypertension 

Definition

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.

Description

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:

• Primary pulmonary hypertension. The cause of pulmonary hypertension is unknown. It is rare, affecting one people per-million. The illness most often occurs in young adults, especially women.
• Secondary pulmonary hypertension. Secondary pulmonary hypertension is increased pressure of the blood vessels of the lungs as a result of other medical conditions.

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.

Causes and symptoms

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.

Diagnosis

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.

Treatment

The aim of treatment for pulmonary hypertension is to treat the underlying cause, if it is known. For example, thromboendarterectomy is a surgical procedure performed to remove a blood clot on the lung that is causing the pulmonary hypertension. Lung transplants are another surgical treatment.

Some patients are helped by taking medicines that make the work of the heart easier. Anticoagulants, drugs that thin the blood, decrease the tendency of the blood to clot and allow blood to flow more freely. Diuretics decrease the amount of fluid in the body and reduce the amount of work the heart has to do. Calcium channel blockers relax the smooth muscle in the walls of the heart and blood vessels and improve the ability of the heart to pump blood.

One effective medical treatment that dilates blood vessels and seems to help prevent blood clots from forming is epoprostenol (prostacyclin). Prostacyclin is given intravenously to improve survival, exercise duration, and well-being. It is sometimes used as a bridge to help people who are waiting for a lung transplant. In other cases it is used for long-term treatment.

Some people require supplemental oxygen through nasal prongs or a mask if breathing becomes difficult.

Prognosis

Pulmonary hypertension is chronic and incurable with an unpredictable survival rate. Length of survival has been improving, with some patients able to live 15-20 years or longer with the disorder.

Prevention

Since the cause of primary pulmonary hypertension is still unknown, there is no way to prevent or cure this disease. A change in lifestyle may assist patients with daily activities. For example, relaxation exercises help to reduce stress. Good health habits such as a healthy diet, not smoking, and getting plenty of rest should be maintained.

Key terms

Hypertension — The medical term for abnormally high blood pressure.

Perfusion lung scan — A scan that shows the pattern of blood flow in the lungs.

Pulmonary — Having to do with the lungs.

Pulmonary function test — A test that measures how much air the lungs hold and the air flow in and out of the lungs.

Right-heart cardiac catherization — A medical procedure during which a physician threads a catheter into the right side of the heart to measure the blood pressure in the right side of the heart and the pulmonary artery. The right heart's pumping ability can also be evaluated.

Resources

Organizations

American Association for Respiratory Care. 11030 Ables Lane, Dallas, TX 75229. (972) 243-2272. http://www.aarc.org.

Pulmonary Hypertension Association. P.O. Box 24733, Speedway, IN 46224-0733. (800) 748-7274. http://www.phassociation.org.

Other

"Primary Pulmonary Hypertensiton." National Heart, Lung, and Blood Institute. 〈http://www.nhlbi.nih.gov/nhlbi/lung/other/gp/pph.txt〉.

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hypertension /hy·per·ten·sion/ (-ten´shun) persistently high arterial blood pressure; it may have no known cause (essential, idiopathic, or primary h.) or may be associated with other diseases (secondary h.) .

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accelerated hypertension  progressive hypertension with the funduscopic vascular changes of malignant hypertension but without papilledema.

adrenal hypertension  that associated with an adrenal tumor which secretes mineralocorticoids.

borderline hypertension  a condition in which the arterial blood pressure is sometimes within the normotensive range and sometimes within the hypertensive range.

Goldblatt hypertension  that caused experimentally by a Goldblatt kidney.

labile hypertension  borderline h.

malignant hypertension  a severe hypertensive state with papilledema of the ocular fundus and vascular hemorrhagic lesions, thickening of the small arteries and arterioles, left ventricular hypertrophy, and poor prognosis.

ocular hypertension  persistently elevated intraocular pressure in the absence of any other signs of glaucoma; it may or may not progress to chronic simple glaucoma.

portal hypertension  abnormally increased pressure in the portal circulation.

pulmonary hypertension  abnormally increased pressure in the pulmonary circulation.

renal hypertension  that associated with or due to renal disease with a factor of parenchymatous ischemia.

renovascular hypertension  that due to occlusive disease of the renal arteries.

systemic venous hypertension  elevation of systemic venous pressure, usually detected by inspection of the jugular veins.

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pulmonary hypertension

n.

Hypertension in the pulmonary circulation; it may be primary or secondary to pulmonary or cardiac disease.

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pulmonary hypertension,

abnormally high blood pressure within the pulmonary circulation. See also cor pulmonale.

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hypertension

persistently high blood pressure. Detected sporadically in animals partly due to the technical difficulties in diagnosis and the lack of recognizable signs. Greyhounds normally have a higher blood pressure than is found in crossbred dogs with features resembling essential hypertension in humans. Secondary hypertension due to advanced renal disease, hyperthyroidism and hyperadrenocorticism does occur in dogs and cats. Temporary episodes of hypertension occur in all animals suffering severe pain, and in horses with acute laminitis.

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endocrine hypertension

that occurring in association with diseases of the endocrine glands.

Goldblatt hypertension

see Goldblatt kidney.

inherited hypertension

see rat hypertension (below).

neurogenic hypertension

produced experimentally in laboratory animals by the imposition of surgical and psychological insults on the central nervous system.

ocular hypertension

persistently elevated intraocular pressure in the absence of any other signs of glaucoma; it may or may not progress to chronic simple glaucoma.

portal hypertension

abnormally increased pressure in the portal circulation caused by impedance of blood flow through a diseased liver or portal vein.

pulmonary hypertension

results from high-pressure blood flow from the right ventricle or impedance to blood flow through the lungs or through the left heart. Chronic hypertension causes endothelial degeneration and fibroplasia of vessel walls. The end result may be cor pulmonale or pulmonary edema. See also altitude sickness, cor pulmonale.

rat hypertension

several strains of spontaneously hypertensive rats have been bred.

renal hypertension

secondary hypertension.

systemic venous hypertension

elevation of systemic venous pressure, usually detected by inspection of the jugular veins.

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pulmonary hypertension

Idiopathic pulmonary hypertension, primary pulmonary hypertension Internal medicine An idiopathic condition more common in ♀ age 20 to 40 characterized by ↑ blood pressure in pulmonary arteries in absence of other heart or lung disease; the major effect of PH is ↑ right ventricular load which, when prolonged, predisposes Pts to right ventricular failure, syncope, precordial pain, sudden death Types Idiopathic, 2º to Eisenmenger's complex, respiratory failure in cystic fibrosis and COPD, with inhibition of endothelium-dependent pulmonary arterial relaxation due to ↓ synthesis of nitric oxide or endothelium-derived growth factor Prognosis No longer thought to be universally fatal Treatment High-dose CCBs may induce ↓ pulmonary artery pressure and pulmonary vascular resistance, which may be combined with warfarin

Pulmonary Hypertension

Passive pulmonary hypertension, characterized by systemic congestion due to mitral stenosis, left ventricular failure, left atrial myxoma, anomalous drainage of the pulmonary circulation

Hyperkinetic pulmonary hypertension, with ↑ blood flow through lungs due to congenital heart defects

Vaso-occlusive pulmonary hypertension, due to recurring vessel obstruction, seen in IV drug abuse and PTE, associated with hypoxia, alveolar hypoventilation (mitral stenosis, coarctation of aorta, Eisenmenger's complex, ventricular septal defect)

Secondary pulmonary hypertension–comprises 10-20% of cases, treated by addressing the underlying disease, eg unilateral renal artery stenosis, coarctation of aorta, primary aldosteronism, pheochromocytoma