Pulmonary hypertension (PH or PHTN) is a condition of increased blood pressure within the arteries of the lungs. Symptoms include shortness of breath, syncope, tiredness, chest pain, swelling of the legs, and a fast heartbeat.
The condition may make it difficult to exercise. Onset is typically gradual. The cause is often unknown. Risk factors include family history, prior blood clots in the lungs, HIV/AIDS, sickle cell disease, cocaine use, COPD, sleep apnea, living at high altitudes, and problems with the mitral valve. The underlying mechanism typically involves inflammation of the arteries in the lungs. Diagnosis involves first ruling out other potential causes.
There is no cure. Treatment depends on the type of disease. Several supportive measures such as oxygen therapy, diuretics, and medications to inhibit clotting may be used. Medications specifically for the condition include epoprostenol, treprostinil, iloprost, bosentan, ambrisentan, macitentan, and sildenafil. A lung transplant may be an option in certain cases.
Pulmonary hypertension Types
The World Health Organization has established five groups of pulmonary hypertension.
Group 1 pulmonary arterial hypertension (PAH)
Group 1 PAH includes pulmonary hypertension that has no known cause; is inherited; is caused by drugs or toxins; is caused by conditions such as connective tissue disease, HIV infection, liver disease, congenital heart disease, sickle cell disease, or schistosomiasis; or is caused by conditions that affect the veins and small blood vessels of the lungs.
Group 2 pulmonary hypertension
Group 2 pulmonary hypertension is often associated with left heart diseases such as mitral valve disease or long-term high blood pressure. Left heart disease is the most common cause of pulmonary hypertension.
Group 3 pulmonary hypertension
Group 3 is related to lung problems like chronic obstructive pulmonary disease (COPD) and interstitial lung disease, as well as sleep apnea and other sleep-related breathing disorders.
Group 4 pulmonary hypertension
Group 4 includes pulmonary hypertension caused by blood clots in the lungs or general clotting disorders.
Group 5 pulmonary hypertension
Group 5 includes pulmonary hypertension triggered by other disorders. Examples of such diseases or conditions are blood disorders such as polycythemia vera and essential thrombocythemia; systemic disorders such as sarcoidosis and vasculitis; metabolic disorders such as thyroid and glycogen storage disease; and other conditions such as kidney disease and tumors that press on the pulmonary arteries.
Pulmonary hypertension Symptoms
Many people with pulmonary hypertension may have no symptoms at all, especially if the disease is mild or in the early stages.
Pulmonary hypertension symptoms may include:
- Shortness of breath that worsens with activity
- Other common complaints are cough, fatigue, dizziness, and lethargy.
- With the advancement of the condition and ensuing right heart failure, shortness of breath may become worse and retention of fluid in the body may increase (due to failure of the heart to pump blood forward) resulting in swelling the legs.
- People may also complain of chest pain and angina.
- Depending on the underlying associated disease, pulmonary artery hypertension can have other manifestations. For example, characteristic skin changes were seen in scleroderma or the signs of liver disease seen in portopulmonary hypertension.
Signs of pulmonary hypertension may include:
- Rapid breathing, hypoxia (low oxygen level in the blood), and swelling in the legs.
- In severe pulmonary hypertension, the health care professional may hear louder than normal components of heart sounds when he or she listens to the heart with a stethoscope (auscultation).
- The doctor may also feel elevation of the chest wall when the heart pumps and this may indicate enlargement of the right side of the heart suggestive of pulmonary hypertension (right ventricular heave).
Pulmonary hypertension Causes
There are many causes of pulmonary hypertension. Often more than one mechanism is involved in a specific disease process. This can also change as the disease progresses.
- Diseases that affect flow out of the heart to the rest of the body result in backflow of blood (stacking of blood) that raises pulmonary venous pressures leading to pulmonary hypertension.
- Hypoxic pulmonary vasoconstriction is the process in which the lung vessels narrow in an attempt to divert blood from poorly functioning segments of the lung. For instance, when pneumonia develops, a portion of the lung becomes inflamed and works poorly in performing the functions of the lung (to add oxygen and remove carbon dioxide from the blood). This process diverts blood from these poorly working areas and sends it to better functioning lung tissue. However, a problem develops when all the blood has a low oxygen level (hypoxia). This causes constriction of the vessels on the pulmonary arterial side and hence raises the pressure.
- Remodeling of blood vessels also occurs in some diseases whereby the inner lining (lumen) of the vessel becomes narrowed due to inappropriate growth of the tissue within and around the vessel. Masses and scarring from other diseases can compress and narrow vessels causing increased resistance to flow resulting in elevation of pressures.
- In a fairly common parasitic infection in the Middle East (schistosomiasis), the blood vessels in the lung become blocked by the parasites causing pulmonary artery hypertension.
- Some substances cause constriction of the blood vessels. Pulmonary hypertension has been rarely reported with the use of anti-obesity drugs, such as dexfenfluramine (Redux) and Fen/Phen. These medications have seen been removed from the market. Some street drugs such as cocaine and methamphetamines can cause severe pulmonary hypertension.
- Some diseases raise pulmonary pressures to cause pulmonary artery hypertension for unclear reasons. Perhaps an unknown toxin or chemical affects the blood vessels by causes constriction or inappropriate growth of the tissue within or around the vessel. For example, there is a condition known as portopulmonary hypertension that is a result of liver failure. When these individuals receive a liver transplant, pulmonary hypertension disappears suggesting that the failing liver is unable to clear some biochemical that leads to pulmonary artery hypertension.
Pulmonary hypertension Risk factors
Your risk of developing pulmonary hypertension may be greater if:
- You’re a young adult, as idiopathic pulmonary arterial hypertension is more common in younger adults
- You’re overweight
- You have a family history of the disease
- You have one of the various conditions that can increase your risk of developing pulmonary hypertension
- You use illegal drugs, such as cocaine
- You take certain appetite-suppressant medications
- You have an existing risk of developing pulmonary hypertension, such as a family history of the condition, and you live at a high altitude
Pulmonary hypertension Complications
Pulmonary hypertension can lead to several complications, including:
- Right-sided heart enlargement and heart failure (cor pulmonale). In cor pulmonale, your heart’s right ventricle becomes enlarged and has to pump harder than usual to move blood through narrowed or blocked pulmonary arteries.At first, the heart tries to compensate by thickening its walls and expanding the chamber of the right ventricle to increase the amount of blood it can hold. But this thickening and enlarging works only temporarily, and eventually the right ventricle fails from the extra strain.
- Blood clots. Clots help stop bleeding after you’ve been injured. But sometimes clots form where they’re not needed. Many small clots or just a few large ones dislodge from these veins and travel to the lungs, leading to a form of pulmonary hypertension that can generally be reversible with time and treatment.Having pulmonary hypertension makes it more likely you’ll develop clots in the small arteries in your lungs, which is dangerous if you already have narrowed or blocked blood vessels.
- Arrhythmia. Irregular heartbeats (arrhythmias) from the upper or lower chambers of the heart are complications of pulmonary hypertension. These can lead to palpitations, dizziness or fainting and can be fatal.
- Bleeding. Pulmonary hypertension can lead to bleeding into the lungs and coughing up blood (hemoptysis). This is another potentially fatal complication.
Factors that can affect pulmonary hypertension
While pulmonary hypertension has no cure, you can live an active, fulfilling life by working with your doctor to manage your symptoms. Talk to your doctor before taking over-the-counter medicine, as some can worsen symptoms of pulmonary hypertension or interfere with prescriptions — and keep a list of medicines with you. Ask whether you should get a pneumonia vaccination or flu shot. Additionally, pregnancy can pose serious risks for women with pulmonary hypertension, so be sure to discuss birth control options with your physician.
These lifestyle changes can improve your symptoms:
- Quit smoking. Your doctor can recommend programs and products to help.
- Follow a healthy diet. Eat a variety of fruits, vegetables, and whole grains, plus lean meat, poultry, fish and low-fat/fat-free milk. Your diet should be low in fat, cholesterol, sodium, and sugar.
- Watch your weight. A daily record of your weight can help you be aware of rapid weight gain, which may be a sign that your pulmonary hypertension is worsening.
- Stay active. Incorporate physical activity such as walking into your lifestyle. Discuss the level of activity with your doctor. Avoid straining or lifting heavyweights. Rest when you need to.
- Avoid sitting in a hot tub or sauna, or taking long baths, which will lower your blood pressure.
- Be cautious about air travel or high-altitude locales. You may need to travel with extra oxygen.
- Get support for the anxiety and stress of living with pulmonary hypertension. Talk with your healthcare team, or ask for a referral to a counselor. A support group for people living with pulmonary hypertension can be invaluable in learning how to cope with the illness.
Pulmonary hypertension diagnosis
The first step in the diagnosis of pulmonary hypertension is to clinically suspect it. This may be done as part of an evaluation of another disease that can lead to pulmonary hypertension (such as scleroderma or chronic obstructive pulmonary disease), or based on patients and signs and symptoms as described above.
Echocardiogram, Doppler, heart catheterization
- Many tests, such as an echocardiogram, may be performed that may give clues to the possibility of pulmonary hypertension. A Doppler study must be performed with the echocardiogram, which enables the doctor to approximate the pulmonary artery pressures. These values are calculated based on the sound quality of the wave approaching and leaving the echocardiogram machine sensor/probe. This is based on the principle that explains why the sound of approaching and then passing train varies.
- But the gold standard (the best test available) is right heart catheterization. This test entails inserting a catheter through the groin into the femoral vein, a large vein in the lower body (or under the collar bone or in the upper arm or neck into a large vein in the upper body) and advancing it to the right side of the heart. The catheter is connected to a device that can monitor and measure blood pressure on the right side of the heart and pulmonary arteries.
- During right heart catheterization, oxygen levels are measured during various positions of the catheter in the pulmonary circulation. This can help determine if a congenital or acquired hole has formed in the heart contributing to the elevated pulmonary pressures. Certain medications or activities can be administered or performed during the procedure to help with the assessment. Nitric oxide can be inhaled and in certain forms of PAH, a dramatic improvement in pressures can occur suggesting specific treatment options such as the use of calcium channel blocker medication. Some patients have an exaggerated pulmonary pressure response to exercise and this too can be measured by utilizing arm exercise during the procedure. Titration of medications for pulmonary hypertension, while the catheter is in place, can help monitor the response to treatment and assist in optimizing therapy. This can assist in providing individualized therapy for patients with this complex disease.
Pulmonary hypertension is defined as the mean pulmonary artery blood pressure greater than 25 millimeters of mercury (mmHg) measured by right heart catheterization. The pressures can be much higher than 25 mmHg in some people. Therefore, pulmonary hypertension can be labeled as mild, moderate, or severe based on the pressures. Mean arterial pressure calculated by multiplying the diagnostic pressure two times, and adding the systolic pressure to that number, and then divide by three (systolic is the upper number and diastolic is the lower number in measuring blood pressure). Normally, the pulmonary blood pressure is much lower pressure system than the systemic blood pressure (which is usually measured with a blood pressure cuff).
What tests may be used in diagnosing pulmonary hypertension?
Other tests available for diagnosing pulmonary hypertension include an electrocardiogram (ECG, EKG), chest X-ray, and echocardiogram. An ECG may show some abnormalities that may be suggestive of right heart failure. A chest x-ray may also show enlargement of the chambers of the right heart. An echocardiogram (ultrasound of the heart) shows ultrasound images of the heart and can detect evidence of right heart failure and with the use of Doppler (as described previously) can estimate pressures in the pulmonary artery. These tests, in the right clinical setting, are very useful in diagnosing and managing pulmonary hypertension.
Other tests may be useful in evaluating the conditions leading to secondary pulmonary hypertension. For example, a ventilation-perfusion scan (V/Q scan) can suggest blood clots in the pulmonary arteries or sometimes a CT scan of the chest can be used. The chest CT scan can detect pulmonary arterial clots, but also can show abnormalities of the lung tissue and surrounding structures that can contribute to pulmonary hypertension.
Pulmonary function testing can be useful in diagnosing chronic obstructive pulmonary disease (COPD), and other lung diseases, and monitor disease progression. This test can be used to detect many aspects of lung function including airflow and evidence of obstruction, lung volumes, and the capacity for the lung to extract oxygen from the air.
Sleep studies can confirm the diagnosis of sleep apnea and its severity and management options such as CPAP therapy.
Pulmonary hypertension treatment
The treatment for pulmonary hypertension depends on the underlying cause.
- If left-sided heart failure is the primary problem, then adequate treatment of the left heart failure by a cardiologist is the mainstay of treatment.
- In cases where hypoxia (low oxygen levels) due to any chronic lung disease, such as COPD, is the cause, then providing oxygen and appropriately treating the underlying lung disease by a lung doctor (pulmonologist) is the first step in treatment.
- In some patients, the elevated pressure may be related to obstructive sleep apnea syndrome (OSAS) and can be reduced with the use of a CPAP, (a device that delivers positive airway pressure during sleep).
- In conditions, such as scleroderma, which often can cause pulmonary hypertension, a rheumatologist is involved in the treatment program.
- Anticoagulation (thinning the blood) may be a treatment option if the main underlying cause is thought to be a recurrent blood clot (chronic thromboembolic pulmonary hypertension). As indicated in the previous section, referral to a specialty center may be warranted for possible surgical removal of a blood clot (thromboendarterectomy).
- For patients with primary pulmonary hypertension (those with no underlying cause), more advanced therapy may be attempted. These drugs have complex mechanisms, but in general, they work by dilating (opening up) the pulmonary arteries and, therefore, by reducing the pressure in these blood vessels and some help prevent the excessive overgrowth of tissue in the blood vessels (that decrease remodeling of the vessels, as described previously). Besides constriction, PAH can result in an actual structural change of the pulmonary arteries, whether it is due to chronically elevated pressures or the disease itself, or a combination of the two is not completely clear. These drugs also can delay and in some cases reduce the degree of remodeling of the pulmonary arteries.
There are three major classes of drugs used to treat idiopathic pulmonary hypertension and pulmonary hypertension associated with collagen vascular diseases: 1) prostaglandins; 2) phosphodiesterase type 5 inhibitor; and 3) endothelium-receptor antagonists.
- Prostaglandins such as epoprostenol (Flolan), treprostinil (Remodulin, Tyvaso), iloprost (Ventavis). These drugs are very short-acting and often must be given intravenously or inhaled on a very frequent or continuous basis.
- Phosphodiesterase type 5 inhibitors such as sildenafil (Revatio, Viagra) and tadalafil (Adcirca, Cialis) are somewhat less effective than the prostaglandins but are easily administered one to three times per day by mouth. (The dosing is much different when these drugs are used for erectile dysfunction.)
- Endothelium antagonists are the newest medications used for this condition. These include bosentan (Tracleer) and Ambrisentan (Letairis). These medications are also given by mouth one to two times per day.
What other drugs treat pulmonary hypertension?
- A unique drug, riociguat (Adempas), that is indicated for pulmonary hypertension due to chronic thromboembolic disease (CTEPH). The mechanism of action is different from the drugs above. It works by increasing the effect of nitric oxide causing increased pulmonary vasodilation.
- In rare cases, calcium channel blockers (CCBS) may be of benefit.
Currently, research is investigating the best ways to combine these medications for optimal clinical outcomes. It should be noted that these medications are extremely expensive, costing dollars per year. The companies that manufacture these medications often have programs to assist in funding. These more advanced therapies have also been used for other forms of pulmonary hypertension, however, no clinical studies have yet confirmed benefits in these situations.
Frequently Asked Questions about Pulmonary hypertension
What is pulmonary hypertension?
Pulmonary hypertension (often shortened to PH) is a serious condition where the blood pressure in the pulmonary arteries is high. This causes progressive damage to the heart and lungs.
What is next after the diagnosis?
After you have been diagnosed with PH your specialist PH team will discuss treatment options with you. The treatments you receive will depend on the type of PH you have and how severe it is.
Where will I be treated?
Nine specialist PH centers in the UK and Ireland look after people with PH. You can choose which specialist center you are treated at.
You normally only visit your specialist PH center once or twice a year, although sometimes you may need to visit it every 3 or 4 months.
Is there a cure?
Despite advances in various treatments, there is no cure for pulmonary hypertension.
What is the life expectancy?
Generally, the prognosis of pulmonary varies depending on the underlying condition that is causing it. For idiopathic or familial pulmonary hypertension, the overall prognosis depends on the severity and whether treatment was instituted. The statistics show the survival of about 3 years in idiopathic pulmonary hypertension without any therapy. Some of the other factors may indicate even poorer prognosis which includes severe symptoms, age of onset greater than 45 years, evidence of right-sided heart failure, and failure to respond to treatment. For patients with idiopathic pulmonary hypertension who get started on treatment and respond to it, the prognosis is better. Studies are underway to determine optimal treatment regimens.
Which types of doctors treat pulmonary hypertension?
Generally, pulmonary physicians (pulmonologists) and cardiologists treat pulmonary hypertension. Depending on the cause, other physicians also may be involved such as sleep medicine doctors, rheumatologists, and perhaps even infectious disease specialists. Today, more health-care professionals in the community are becoming adept at managing pulmonary hypertension. However, it is reasonable to get a second opinion regarding management at a tertiary, university setting because the field of management of pulmonary artery hypertension is evolving rapidly.
What is the outlook for people with PH?
The outlook for a person with PH is different for each person. This depends on some things:
- How severe your PH is
- Associated conditions
- Overall general health
- Your lifestyle
- Response to treatments.
Overall, the outlook for people with PH has improved dramatically over the last 20 years. This is because of the introduction of new, effective treatments for PH.
You should talk to your PH specialist team if you would like to know more about what to expect.
What treatments are available for people with PH?
There are several different treatments available for PH. These include conventional treatments (often called supportive or background therapy) and targeted treatments.
Some treatments for PH can help improve symptoms and some may slow disease progression and reverse damage to the heart and lungs.
For more information about different treatments for PH visit the Treatments section, or talk to your specialist PH team.
Can I choose which treatment I receive?
Your specialist PH team will discuss the best treatment options with you. If you have any questions or concerns, don’t hesitate to ask.
How will having PH affect me on a day-to-day basis?
Having PH will affect you on a day-to-day basis but that doesn’t mean it has to stop you from doing the things you like.
You may feel more tired than usual or become breathless doing simple tasks such as housework or walking upstairs. You may have to take your treatments at certain times of the day, which could impact on daily activities.
How does PH affect pregnancy?
Pregnancy is risky for both a mother with PH and her unborn baby. If a PH patient becomes pregnant, she needs to consult with a doctor immediately. It also is important to note that birth control pills are risky for women with PH as they can increase the likelihood of blood clots. Thus, patients should consult with a doctor about alternative forms of birth control.
How does PH affect patients’ lives?
Life can change dramatically once a person is diagnosed with pulmonary hypertension. So, it is important to develop strategies to cope with the physical and emotional challenges of living with the disease. There are several ways in which people with PH can find work, travel, exercise, and do the activities they loved before their diagnosis. For tips, visit the Living with PH section of our website.
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