Pulmonary hypertension is high blood pressure in the blood vessels that deliver oxygen rich blood to the lungs. It is a serious condition that can lead to heart failure and even death.
In the United States, there are around 200,000 hospitalizations each year involving pulmonary hypertension. The condition is responsible for around 15,000 fatalities every year.
It is most common in people aged 75 years or older.
A 2017 review estimates that the average 3-year survival rate of people with pulmonary hypertension is around 70–80%.
In this article, we explain pulmonary hypertension and look at how to improve the outlook through early diagnosis and treatment.
Pulmonary hypertension is an abnormal blood pressure increase in the pulmonary artery. This vital blood vessel provides oxygen rich blood to the lungs from the right-hand side of the heart.
If hypertension, or high blood pressure, occurs near the lungs in a person’s circulation, it is likely to get worse and cause serious health problems.
Pulmonary hypertension is not the same as hypertension. Hypertension involves high blood pressure across a range of bodily systems and mainly affects the wider circulatory system.
A person’s pulmonary blood pressure should range from 8–20 millimeters of mercury (mm Hg) while resting.
Doctors define pulmonary hypertension as pulmonary artery pressure that is higher than 25 mm Hg.
There are two types of pulmonary hypertension:
- Primary pulmonary hypertension: This is a relatively rare condition that does not occur due to an underlying condition.
- Secondary pulmonary hypertension: This stems from an underlying condition, such as a congenital heart anomaly or chronic obstructive pulmonary disease (COPD).
The main symptom of pulmonary hypertension is shortness of breath, or dyspnea. Breathlessness can affect a person’s ability to walk, talk, and physically exert themselves.
Some other primary symptoms include fatigue, fainting, and dizziness.
It is important to note that pulmonary hypertension might produce no symptoms at all until the condition reaches a more severe stage.
The back pressure on the heart and the increased effort needed to maintain blood flow can lead to a heart disease called right ventricular hypertrophy.
This causes a collapse in the right ventricle of the heart due to thickened arterial walls. This causes the heart to overwork, the ventricle to get bigger, and blood pressure to increase.
This is a life threatening complication, as it can lead to heart failure. Heart failure is the main cause of death for people with pulmonary hypertension.
Other complications include blood entering the lungs and coughing up blood, or hemoptysis. Both of these complications can be fatal.
Blood clots and an irregular heartbeat, or arrhythmia, are other possible complications of pulmonary hypertension.
If a person suspects that they have pulmonary hypertension, they should seek medical attention as soon as possible.
Receiving prompt medical help can reduce the risk and severity of complications.
The thickening of the blood vessel walls in the lung causes pulmonary hypertension.
This narrows the space within the vessel through which blood can travel, increasing the pressure.
A complex set of factors leads to the thickening of blood vessels in the lungs, including:
- problems with connective tissue, such as sclerosis
- congenital heart anomalies, or structural issues that have been present since birth
- inherited genetic causes, such as a BMPR2 gene mutation
- the use of drugs or other toxins
- liver disease, such as cirrhosis, which occurs due to scarring of the liver
- long term kidney failure
- pulmonary embolism, wherein blood clots form in or move to the lungs
- sarcoidosis, in which the immune system causes lumps to form in organs throughout the body
- sickle cell anemia
- lung tumors
- metabolic disorders, including thyroid disorders
- left heart diseases, such as heart valve disease and aortic stenosis
- parasitic infection, including tapeworms such as Echinococcus
- lung diseases such as COPD
- regular exposure to high altitudes
A range of factors can cause pulmonary hypertension, and the condition may occur alongside different types of heart or lung disease. As a result, the cause of the pulmonary hypertension can often be difficult to diagnose.
A doctor will ask about family and medical history and carry out a physical exam.
If they suspect that a person has pulmonary hypertension, they will usually suggest a series of tests, including:
- A chest X-ray: A doctor usually combines this with CT or MRI scans to help find the underlying cause of pulmonary hypertension.
- Electrocardiogram: This measures the electrical activity of the heart.
- Right sided heart catheterization: This measures pulmonary blood pressure.
A doctor diagnoses pulmonary hypertension when the pressure in the pulmonary artery is higher than 25 mm Hg at rest or 30 mm Hg during exertion.
The 6-minute walk test (6MWT) allows a doctor to assess the progression of pulmonary hypertension and assign a stage to the condition. Staging demonstrates the severity of the condition on a scale of 1 to 4.
Stage 1 refers to a symptomless presentation of the condition, in which physical activity does not cause discomfort. Stage 4 means that a person experiences the symptoms of pulmonary hypertension even while at rest.
The 6MWT measures how far a person with suspected pulmonary hypertension can walk in 6 minutes, as well as how their body responds to the activity.
After staging the condition, the doctor will devise an appropriate treatment plan. They can also use the 6MWT to gauge the outlook of the condition.
Treatment for pulmonary hypertension depends on the underlying cause, any co-occurring health problems, and the severity of the condition.
Therapies that may help a person manage their condition include low intensity exercise such as walking. This can help them improve their capacity for physical exertion.
Continuous oxygen therapy may be necessary to help maintain oxygen saturation in the blood, especially among those who also have lung disease.
During a high altitude flight, people may need oxygen therapy to compensate for reduced the oxygen levels.
In oxygen therapy, a doctor administers additional oxygen from outside the body. They will deliver the oxygen from a tank through an oxygen mask or tubes in the nose and windpipe.
Drugs for pulmonary hypertension
Several drugs, either in isolation or in combination with each other, can support the management of pulmonary hypertension. For example:
- Diuretics: These help a person reduce fluid retention and swelling. They are also known as water pills.
- Digoxin: A person can use these to manage heart failure. Digoxin helps control heart rate and rhythm and increases the amount of blood that the heart can pump with each heartbeat.
- Blood thinning drugs such as warfarin: These can help reduce the risk of blood clots, which are more likely in people with pulmonary hypertension.
- Calcium channel blockers such as diltiazem: These help the blood vessels widen to improve blood flow.
- Phosphodiesterase-5 (PDE5) inhibitors: These also increase blood flow by making blood vessels wider. Sildenafil is one example of a PDE5 inhibitor.
- Endothelin receptor antagonists such as bosentan and ambrisentan: These limit the constriction of arteries that can develop when a person has too much natural peptide.
Inhaled options, such as iloprost (Ventavis) or treprostinil (Tyvaso), can help relieve breathlessness.
More invasive treatments may be necessary when medication is not having the desired effect.
Surgical options include:
- Atrial septostomy: In this procedure, a surgeon will introduce a shunt to the area between the heart chambers. This improves the output of the heart while a person awaits transplant surgery.
- Lung transplant: This is a procedure to replace one lung or both lungs.
- A combined heart and lung transplant: This procedure is an intensive double transplant.
Chronic thromboembolic pulmonary hypertension is one presentation of high blood pressure in the lungs that also involves a number of blood clots in the arteries.
Some people with chronic thromboembolic pulmonary hypertension may undergo a procedure called a pulmonary thromboendarterectomy. This is specialized heart surgery to remove blood clots from coronary arteries.
Although many treatments are available to ease the symptoms, improve the outlook, and slow its progression, there is currently no cure for pulmonary hypertension.
Can general hypertension increase the risk of pulmonary hypertension?