Pulmonary hypertension diagnosis: Tests, criteria, what to expect - Medical News Today

Several tests can help a doctor determine if a person has pulmonary hypertension. The tests are mostly outpatient procedures with minimal risk to the person getting tested.

Pulmonary hypertension is an elevation in the blood pressure of the lungs. It can happen due to heart disease, but can also be spontaneous due to clots or other chronic diseases.

A doctor may recommend one or more tests to help diagnose pulmonary hypertension and its causes.

This article lists some of the most common tests doctors may use to diagnose pulmonary hypertension.

As part of an initial diagnosis of pulmonary hypertension, a doctor may order a chest X-ray.

A chest X-ray can show whether a person has an enlarged right ventricle or pulmonary arteries as well as signs of scarring or other issues related to the lungs.

What to expect

X-rays use some radiation during the procedure. A person should talk with their doctor about associated risk factors before doing the procedure. For example, they should tell their doctor if they are pregnant or may become pregnant, as X-rays may be harmful in this case.

Before the procedure, a person does not need to do anything to prepare in most cases.

An X-ray is an outpatient procedure where the person will wear a gown and either sit, lay, or stand while a technician takes the images. A person should follow all instructions from their technician or doctor. The technician or doctor will be able to answer any questions a person may have.

Before diagnosing pulmonary hypertension, a doctor will likely order blood work or tests.

Blood tests can show a variety of things, including:

• oxygen levels in the blood
• liver function
• kidney function
• the presence of collagen vascular disease
• thyroid issues
• signs of infection
• the presence of HIV
• brain natriuretic peptide, to assess strain on the heart

A person should talk with their doctor about any special instructions before taking a blood sample. A blood sample is generally considered noninvasive and involves taking a small sample of blood through a needle.

Learn more about what to expect during a blood test here.

A 6-minute walk test, or exercise tolerance test, can show how well a person responds to exercise. In most cases, the test involves 6 minutes of walking, often on a treadmill in the medical office.

The test can show whether a person's doctor will need to do more extensive testing on lung or heart functioning. It can also help doctors understand the outlook for a person with pulmonary hypertension.

What to expect

A person does not typically need to do any special preparation for the test. They should wear comfortable clothing and shoes for movement and avoid exercise for 2 hours before the test.

Before the test, a technician will typically take the person's vitals, including blood pressure, pulse, and oxygen levels. Sometimes, they will perform an oxygen saturation test before, during, and after walking.

During the test, the person may use any assistive walking devices they have, slow the pace, or take rests at regular intervals.

A person should ask their doctor any specific questions they have before taking the test.

Learn more about the 6-minute walk test here.

A pulmonary function test can show:

• how well the lungs exchange oxygen
• the capacity of the lungs
• how much air moves in and out of the lungs with each breath

Pulmonary function tests are low-risk outpatient procedures. A person may need to stop taking certain medications and not smoke before the test. A person should ask their doctor about any special instructions they need to follow before the test.

What to expect

During the test, a person will sit in a chair with a clip on their nose. The person will place a sterile mouthpiece into their mouth and do all their breathing through their mouth.

A medical technician will provide the person with instructions during the procedure, and will also monitor the person for signs of distress.

Learn more about how pulmonary function tests work here.

An ECG measures the electrical signals of the heart. By itself, this test is not enough to diagnose pulmonary hypertension.

What to expect

The test is noninvasive and involves placing electrodes on the skin. The electrodes measure electrical impulses. Following the ECG, a doctor will need to perform additional testing to complete the diagnosis.

An ECG is an outpatient procedure that requires no preparation, though a person may find wearing loose-fitting clothing helps. A person should follow instructions from their doctor before the test.

A nuclear scan, or ventilation/perfusion scan, examines the way blood flows through the lungs in order to search for blood clots.

During the test, a person will breathe in a small amount of radioactive material. They will also receive an injection of radioactive material.

The material will produce an image of how the blood flows that the doctor can then review.

A person should talk with their doctor about any special instructions they need to follow before the test. A person should not wear jewelry for this test. The doctor will advise if they should stop taking particular medications before the test.

What to expect

During the procedure, a person will often receive an injection and IV line. They will lay on a table while a special camera takes images of the lungs' functioning.

The procedure is outpatient but could take several minutes to several hours.

An echocardiogram is a noninvasive, painless procedure. A doctor can use the test to make a preliminary diagnosis of pulmonary hypertension by measuring the pressure on the right side of the heart and looking at how well the heart is functioning in general.

In addition, a doctor may be able to diagnose other conditions that create similar symptoms to pulmonary hypertension. A doctor may also use the device to monitor a person's condition.

What to expect

A person does not need to do anything special to prepare for the test. During the procedure, a person may expect some of the following to occur:

• The person will lay on a table and have electrodes placed on their chest.
• The technician will apply gel to the skin to help sound waves pass through the skin.
• The technician will run a probe over the chest, and may ask the person to stop breathing for a moment.
• The probe sends out sound and receives an echo back that gets turned into a picture on a screen.

A person should talk with their doctor about any specific questions they have.

Right-heart catheterization measures the pressure inside of the pulmonary arteries.

According to the Pulmonary Hypertension Association, right-heart catheterization is the gold standard of testing and the most useful and accurate test for diagnosing pulmonary hypertension. They recommend using the test at least once to confirm the diagnosis.

Before the procedure, a person should talk with their doctor and let them know if they have any devices implanted in their heart. They should also review any medications and medical history, including whether they may be pregnant. During the consult, a person should ask their doctor about any special instructions they need to be aware of.

What to expect

During the procedure, a person can expect to receive an IV line. They will need to change into a hospital gown and remove any jewelry. The doctor will typically numb the area and provide a sedative if needed to help the person relax.

Once numbed, the doctor will insert the needed tubing and instruments. They will insert a catheter through a thin vein in the groin or neck and feed it through to the right side of the heart and lungs.

Once the doctor gets the information they need, they will remove the device and tubing unless they determine additional testing or monitoring is needed.

Learn more about cardiac catheterization here.

According to a 2019 study, about 25–30% of people living with idiopathic pulmonary arterial hypertension (PAH) have an underlying genetic cause. They propose classification of this type of pulmonary arterial hypertension as heritable PAH (HPAH).

The cause of genetic PAH comes from a change in the mechanism that creates a protein known as bone morphogenetic protein receptor 2 (BMPR2). The altered BMPR2 influences the development of arteries in the lungs, which causes PAH to develop.

If a doctor or person wants to test for HPAH, genetic testing is available. It can tell if a person has a genetic mutation that could or has caused PAH to occur. In about 80% of families, testing has found the mutation in BMPR2.

If the exact BMPR2 is not found, a person in the family living with PAH would need to take the genetic test to find the potential matching protein.

Genetic testing for PAH requires the doctor to take a small sample of blood. A lab can then examine it for the presence of the mutation.

It may be inaccurate to classify pulmonary hypertension according to its severity.

However, there are currently five clinical classifications or groups of pulmonary hypertension. These groupings describe the general cause of the high blood pressure in the lungs. The classifications include:

• PAH: The cause of this type of pulmonary hypertension is stiffening or narrowing of the arteries in the lungs, which cause the right side of the heart to work harder.
• Pulmonary hypertension due to left heart disease: The cause of this group is either a problem with a valve on the left side of the heart or an issue with how it relaxes or squeezes.
• Pulmonary hypertension due to lung disease: The cause of this group is either lung disease or hypoxia (low oxygen levels), where the lungs tighten and cannot get blood to all areas of the lungs.
• Pulmonary hypertension due to chronic blood clots in the lungs: This occurs when a blood clot in the lungs does not dissolve on its own. Doctors can often cure this type with surgery or medication in some cases.
• Pulmonary hypertension due to unknown causes: This type is when a doctor cannot find an exact cause. Some possible associated conditions include certain metabolic disorders, chronic hemolytic anemia, sarcoidosis, sickle cell anemia, or splenectomy.

A doctor may recommend one or more tests to help diagnose pulmonary hypertension. Most of the tests are outpatient with minimal risk, but a person may need to take steps to prepare for the test.

A person should talk with their doctor to determine the best test for them and ask them any questions necessary to get ready for the test.