Tests and diagnosis

By Mayo Clinic Staff

Pulmonary hypertension is hard to diagnose early because it's not often detected in a routine physical exam. Even when the disease is more advanced, its signs and symptoms are similar to those of other heart and lung conditions. Your doctor may do one or more tests to rule out other possible reasons for your condition. The first tests you'll have to diagnose pulmonary hypertension include:

  • Blood tests. Your doctor may order blood tests to check for certain substances in your blood that may show you have pulmonary hypertension or its complications.
  • Chest X-ray. This test may be able to check for pulmonary hypertension if your pulmonary arteries or the right ventricle of your heart is enlarged. The X-ray will appear normal in about one-third of people who have pulmonary hypertension.
  • Doppler echocardiogram. Your doctor may first suspect you have pulmonary hypertension based on the results of this test. This noninvasive test uses sound waves that allow your doctor to see your heart without making an incision. During the procedure, a small, plastic instrument called a transducer is placed on your chest. It collects reflected sound waves (echoes) from your heart and transmits them to a machine that uses the sound wave patterns to compose images of your beating heart on a monitor.

    These images show how well your heart is functioning, and recorded pictures allow your doctor to measure the size and thickness of your heart muscle. Sometimes your doctor will recommend an exercise echocardiogram to help determine how well your heart works under stress. In that case, you'll have an echocardiogram before exercising on a stationary bike or treadmill and another test immediately afterward.

  • Transesophageal echocardiogram. If it's difficult to get a clear picture of your heart and lungs with a standard echocardiogram, your doctor may recommend a transesophageal echocardiogram. In this procedure, a flexible tube containing a transducer is guided down your throat and into your esophagus after using a numbing spray in the back of your throat. From here, the transducer can get detailed images of your heart.
  • Right heart catheterization. After you've had an echocardiogram, if your doctor thinks you have pulmonary hypertension, you'll likely have a right heart catheterization. This test is often the most reliable way of diagnosing pulmonary hypertension. During the procedure, a cardiologist places a thin, flexible tube (catheter) into a vein in your neck or groin. The catheter is then threaded into your right ventricle and pulmonary artery. Right heart catheterization allows your doctor to directly measure the pressure in the main pulmonary arteries and right ventricle. It's also used to see what effect different medications may have on your pulmonary hypertension.

    Right heart catheterization is usually performed during local anesthesia and sedation in a hospital setting. You often can go home soon after the procedure. You'll need someone to drive you home after the test.

Your doctor may order additional tests to check the condition of your lungs and pulmonary arteries, including:

  • Pulmonary function test. This noninvasive test measures how much air your lungs can hold, and the airflow in and out of your lungs. During the test, you'll blow into a simple instrument called a spirometer.
  • Perfusion lung scan. This test uses small amounts of radioactive substances (radioisotopes) to study blood flow (perfusion) in your lungs. The radioisotopes are injected into a vein in your arm. Immediately afterward, a special camera (gamma camera) takes pictures of blood flow in your lungs' blood vessels. A lung scan can then be used to determine whether blood clots are causing symptoms of pulmonary hypertension.

    A perfusion lung scan is usually performed with another test, known as a ventilation scan. In this test, you inhale a small amount of radioactive substance while a gamma camera records the movement of air into your lungs. The two-test combination is known as a ventilation-perfusion (V/Q) scan.

  • Computerized tomography (CT) scan. A CT scan allows your doctor to see your organs in 2-D "slices." In this test, you'll lie in a machine that takes images of your lungs so that your doctors can see a cross-section of them. You might also be given a medication that makes the images of your lungs show up more clearly.
  • Magnetic resonance imaging (MRI). This test, which uses no X-rays, is sometimes used to get images of the blood vessels in your lungs. A computer creates tissue "slices" from data generated by a powerful magnetic field and radio waves. An MRI can't, however, measure artery pressure — a procedure that's necessary to check the effectiveness of any medications you're taking to control IPH.
  • Open-lung biopsy. In rare situations your doctor may recommend an open-lung biopsy. An open-lung biopsy is a type of surgery in which a small sample of tissue is removed from your lungs under general anesthesia to check for a possible secondary cause of pulmonary hypertension. It would be done only to see if certain treatments might be effective for you, or to allow you to discontinue some medications.

Genetic tests

If a family member has had pulmonary hypertension, your doctor may screen you for genes that are linked with pulmonary hypertension. If you test positive, your doctor may recommend that other family members be screened for the same genetic mutation.

Pulmonary hypertension classifications

Once you've been diagnosed with pulmonary hypertension, your doctor may classify the disease using guidelines developed by the World Health Organization.

  • Class I. Although you've been diagnosed with pulmonary hypertension, you have no symptoms.
  • Class II. You don't have symptoms at rest, but you experience fatigue, shortness of breath or chest pain with normal activity.
  • Class III. You're comfortable at rest, but have symptoms when you're physically active.
  • Class IV. You have symptoms even at rest.
Mar. 27, 2013