Chronic thromboembolic pulmonary hypertension (CTEPH) can be difficult to diagnose because its symptoms are similar to those of other conditions. If your doctor suspects you may have CTEPH or another type of pulmonary hypertension (PH), they will run a number of tests, some of which are outlined below.
First, your doctor will screen you with an echocardiogram as an initial assessment of suspected PH. A right heart catheterization (RHC) may be performed to confirm the presence of PH. Then, a diagnosis of CTEPH may be confirmed with a V/Q (ventilation/perfusion) scan.
People who’ve been treated for PE and still have symptoms after 3 months could have CTEPH.
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If your doctor suspects you have PH based on your history, risk factors, and physical examination, he or she may order an echocardiogram. In this non-invasive procedure, electrodes are placed on your chest to monitor your heartbeat, and sound waves are used to create a moving picture of your heart. When performing an echocardiogram, your doctor will look for:
Signs of changes in your heart, including
Enlarged right heart chambers
Backflow of blood when the heart pumps
Pressure in the blood vessels of your lungs
While an echocardiogram alone cannot diagnose CTEPH, it can determine if you have some type of PH. If the results of your echocardiogram suggest you may have PH, your doctor will perform additional tests to find out more.
Images courtesy of Dr. Nick Kim, University of California, San Diego.
A V/Q (ventilation/perfusion) scan is recommended and is the preferred method by experts in the field to screen for CTEPH. It can reveal areas in the lung that are not receiving blood as expected when you breathe.
Two tests make up a V/Q scan—a ventilation scan and a perfusion scan. During the ventilation scan, you inhale radioactive gas through a mask while lying under a scanner. The mask can cause some people to feel claustrophobic or nervous about being in a small space.
During the perfusion scan, your doctor injects a special solution into your vein and places you on a movable table under a scanner. The scanner allows your doctor to see how well blood is flowing through your lungs.
If your V/Q scan comes back negative, there is very little chance that you have CTEPH.
Image: Courtesy of G Heresi-Davila, Cleveland Clinic PTE Program.
If your V/Q scan comes back positive, you could have CTEPH. Your doctor will perform additional tests to confirm your diagnosis.
Image: Courtesy of the PTE Program at University of California, San Diego.
Right heart catheterization
Right heart catheterization (RHC) is required to confirm a diagnosis of PH. It allows your doctor to directly measure the pressures in your heart and lungs. RHC also measures how much blood your heart is pumping and how well it is pumping.
During RHC, your doctor inserts a thin rubber tube, or catheter, through a large vein in your neck or groin. Your doctor then passes the catheter up into your heart in order to measure the blood pressure in the right side of your heart and in your lungs.
Pulmonary angiography shows where there are blockages in your blood vessels. Like RHC, a catheter is inserted through a vein in your neck or groin into your pulmonary arteries. An x-ray dye is injected into your arteries through an intravenous (IV) line, and your doctor is able to take pictures of your lungs on x-ray film.
Pulmonary angiography can determine if chronic blood clots are causing your PH. It is used along with the measurements from RHC to determine if you have CTEPH.