What is pulmonary hypertension?
What are the symptoms of PH?
What causes PH?
How is PH diagnosed?
What treatments are available?
Further Information and Contacts
What is pulmonary hypertension?
Pulmonary hypertension is a rare blood vessel disorder of the lung in which the pressure in the pulmonary artery (the blood vessel that leads from the heart to the lungs) rises above normal levels and may become life-threatening.
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What are the symptoms of PH?
Symptoms of pulmonary hypertension include shortness of breath with minimal exertion, fatigue, chest pain, dizzy spells and fainting.
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What causes PH?
When pulmonary hypertension occurs in the absence of a known cause, it is referred to as primary pulmonary hypertension (PPH). This term should not be construed to mean that because it has a single name it is a single disease. There are likely many unknown causes of PPH. PPH is extremely rare, occurring in about two persons per million population per year.
Secondary pulmonary hypertension (SPH) means the cause is known. A common cause of SPH are the breathing disorders emphysema and bronchitis. Other less frequent causes are inflammatory or collagen vascular diseases such as scleroderma, CREST syndrome or systemic lupus erythematosus (SLE). Congenital heart diseases that cause shunting of extra blood through the lungs like ventricular and atrial septal defects, chronic pulmonary thromboembolism (old blood clots in the pulmonary artery), HIV infection, liver disease and diet drugs like fenfluramine and dexfenfluramine are also causes of pulmonary hypertension.
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How is PH diagnosed?
Pulmonary hypertension is frequently misdiagnosed and has often progressed to late stage by the time it is accurately diagnosed.
The gold standard test for diagnosing PH is right-heart cardiac catheterisation, where the doctor places a thin, flexible tube, or catheter, through an arm, leg, or neck vein, then threads the catheter into the right ventricle and pulmonary artery. Most important in PPH is if the doctor gets a precise measure of the blood pressure in the right side of the heart and the pulmonary artery. It is the only way to get this measure, and must be performed in the hospital by a specialist. During catheterisation, the doctor can also evaluate the right heart's pumping ability; this is done by measuring the amount of blood pumped out of the right side of the heart with each heartbeat.
Prior to performing this test a number of non-invasive tests may suggest the diagnosis, including the electrocardiogram, chest x-ray and echocardiogram. The diagnosis of PPH is made by excluding all known causes of SPH.
Pulmonary hypertension has been historically chronic and incurable with a poor survival rate. However, new treatments are available which have significantly improved prognosis. Recent data indicate that the length of survival is continuing to improve, with some people able to manage the disorder for 15 to 20 years or longer.
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What treatments are available?
Current treatments include calcium channel blocking drugs, prostacyclin, and endothelin receptor antagonists. Calcium is an agent that helps cause smooth muscles cells to contract.
Calcium Channel Blockers (CCB's) block the movement of calcium into the cells of the heart and blood vessels. Blocking the calcium helps to relax blood vessels and increase the supply of blood and oxygen to the heart while reducing its workload. Unfortunately, less than 30% of people with PH respond to CCB's. CCB's are also prescribed for systemic hypertension, but in much lower dosages than when they are prescribed for PH. It is not unusual for CCB's to cause fluid retention.
Prostaglandin is a steroid that is produced naturally in the body in a normally healthy person. It causes blood vessels in the lungs to relax and allows blood to flow through them more easily. People with pulmonary hypertension do not produce enough prostaglandin, so the blood vessels in the lungs are constricted. Prostacyclin, also known as epoprostenol, is a synthetic substance that is administered to remedy this deficiency. Prostacyclin therapy was initially used as a bridge to lung transplantation although it has also emerged as an alternative to transplantation in some people.
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Endothelin receptor antagonists
These are a new class of drugs for the treatment of a number of major diseases, including pulmonary arterial hypertension. Endothelin is a peptide made by the body in the endothelium (a layer of cells which line the heart and blood vessels). It constricts blood vessels and elevates blood pressure. Endothelin is a potent vasoconstrictor that plays an important role in blood flow. In PH, the body produces excess endothelin, contributing to the constriction of blood vessels and affecting the blood pressure in the lungs. Although endothelin is present in healthy people, high concentrations of the substance have been found in the plasma and lungs of people with PH suggesting it is capable of causing PH or increasing the symptoms of PH. Endothelin must connect with an endothelin receptor in order to be activated. Endothelin receptor antagonists block endothelin receptors, thereby limiting harmful excess endothelin in the blood vessels.
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Lung transplantation
Quality of life can be moderately to substantially improved by lung transplantation, and life may be extended beyond your life expectancy prior to transplantation. It is impossible to predict how long you may survive after transplantation. The most critical period is the year after transplantation; this is the period when surgical complications, rejection, and infection are the greatest threat to survival. People who survive the first year are more likely to survive 3 years or longer after transplantation. There are people alive today who had lung transplantation 5 or even more years ago.
Life expectancy after lung transplantation is shorter than for heart, liver, or kidney transplantation, particularly for PPH people. Rejection and infection are the two major complications of lung transplantation. Immunosuppressive (antirejection) medications prescribed by your doctors will help keep the rejection process "turned off." Other medications may be necessary to control and treat rejection if your immune system breaks through the immunosuppressive blockade. Following your doctor's instructions and taking all medications as prescribed help to prevent or control rejection.
Because you will be taking immunosuppressive medications, your immune system will be less able to fight off invading bacteria and viruses. You will be much more susceptible to infections, which are more likely to become severe.
Therapies that may be used in conjunction with treatments include diuretics used to control an excessive amount of watery fluid in cells, tissues or serous cavities (such as the abdomen). Pulmonary hypertension can lead to right heart failure and an excess of fluid in the lower and upper extremities and abdomen. An excess of fluid can also be caused by high-dose calcium channel blockers. Diuretics will cause frequent urination.
Digitalis medicines (Digoxin, Lanoxin) are used to improve the strength and efficiency of the heart or to control the rate and rhythm of the heartbeat. This leads to better blood circulation and reduced swelling of hands and ankles in people with right heart problems. Its value for people with PH has not yet been fully examined but it is often used with calcium channel blockers because CCB's tend to weaken the pumping effectiveness of the heart.
Supplementary oxygen is sometimes prescribed for PH people when someone has an inadequate amount of available oxygen (hypoxaemia) in the blood at rest or with physical activity. Supplementary oxygen, however, is an important addition to treating the symptoms of PH with hypoxemia or under special conditions, such as when hospitalized with a respiratory infection, or at high altitudes or sometimes when travelling by air.
Blood clots are potential complications of PH. Oral anticoagulant therapy (Coumadin, Warfarin) is widely recommended for people with PH because it probably prolongs survival.
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Further information and contacts
The Pulmonary Hypertension Association (UK) aims to provide support, understanding, and information for all those people whose lives are touched by Pulmonary Hypertension.
PHA (UK)
PO Box 2760
Lewes
Sussex BN8 4WA
Tel 0800 3898 156
Fax: 0701 071 5723
Email: enquiries@pha-uk.com
Website: www.pha-uk.com
Page last medically reviewed: Jan '05
