• Right heart catheterization (RHC) is a procedure that can help diagnose pulmonary arterial hypertension (PAH) and monitor disease progression.
• RHC is usually performed as an outpatient procedure and causes relatively little discomfort.
• RHC provides critical measurements of blood pressure in the pulmonary artery and right side of the heart, which are affected by PAH.

Right heart catheterization is a procedure used to diagnose and manage various types of heart and lung disease, including pulmonary arterial hypertension. RHC measures the pressure in the heart and lungs and examines how well blood flows through the heart.

Pulmonary arterial hypertension is a rare type of pulmonary hypertension (PH) that causes narrowing of the arteries and high blood pressure in the lungs. It can lead to serious outcomes like heart disease and right heart failure. Although there is no cure for PAH, a detailed diagnosis and continued monitoring can help inform the best treatment plan.

RHC is the current gold standard for diagnosing PAH and other cardiovascular (heart) diseases. RHC is also a prognostic (predictive) tool for PAH risk assessment, which helps doctors evaluate the progression and prognosis (outlook) of your condition. Risk assessment is an important part of PAH care, particularly for people at a higher risk of dying from the condition.

People with PAH will likely have RHC when being diagnosed and during follow-up appointments. Before you have RHC, it can be helpful to know what to expect.

Before Right Heart Catheterization

Your doctor will help you prepare for RHC. The procedure involves inserting a small, hollow tube called a catheter through your veins and into different areas of the right side of your heart. It measures blood pressure and oxygen levels in the right side of your heart and lungs. It can also help doctors catch any ventricular dysfunction — when the heart ventricles don’t work properly — caused by PAH.

RHC is usually an outpatient procedure performed in a special room called a cardiac catheterization lab or cath lab. However, it may be conducted in an intensive care unit for people with severe illness. If you’re having RHC, you’ll want to arrange transportation home with a friend, family member, or caregiver.

Your doctor will tell you how to prepare for RHC. They’ll review your medical history and let you know if you need to temporarily stop any medications you are taking. It’s important to tell your doctor about all prescription and over-the-counter drugs you currently use.

You’ll also be asked to not eat or drink anything for six hours or more before the procedure.

During Right Heart Catheterization

To begin the procedure, your doctor will insert an intravenous (IV) line into a vein in your arm. This IV line is used to provide fluids and to test how medications affect your heart and pulmonary arteries during the procedure.

During RHC, you’ll lie on your back on a padded exam table. The doctor will attach electrodes to your skin for an electrocardiogram to measure your heart’s electrical activity. You may be given a mild sedative to help you relax, but it won’t put you to sleep.

The area where the catheter will be inserted will be cleaned and shaved, if necessary. You’ll receive a local anesthetic to numb the area — the anesthetic may cause a brief burning sensation — before a small incision is made to insert the catheter. The catheter is usually inserted through a vein in the neck, arm, or groin area and will be guided into the right side of your heart.

Once the catheter reaches the heart, the doctor can take measurements in the right atrium, right ventricle, and pulmonary artery. You may be asked to perform simple exercises during the procedure for some of the measurements.

What RHC Feels Like

You may notice some sensations from the catheter itself and from medications that are tested during catheterization. Some people experience:

• Chest fluttering
• Lightheadedness
• Pressure in their veins
• A warm sensation from the medications

Throughout the procedure, your doctor will ask you how you feel. You can tell them if you experience any pain or discomfort.

Once all the measurements have been taken, the doctor will remove the catheter. RHC takes about an hour.

After Right Heart Catheterization

After the procedure, you will be asked to stay at the facility for a couple of hours to be monitored as you recover. Your doctor may also want to discuss your results and a potential treatment plan.

You’ll receive instructions on how to take care of yourself and the catheter incision after RHC. Due to the mild sedative, you should not drive, operate machinery, or exert yourself physically for a period of time. Your doctor will let you know when it’s safe to do these things.

Members of myPHteam Provide Tips for Right Heart Catheterization

Right heart catheterization might sound scary, but it’s a safe and informative procedure that can help you understand and manage your PAH. Many myPHteam members have expressed concerns about RHC. One member asked, “Did you have to have a right catheterization as well? Gosh, I am so scared.”

However, most myPHteam members who’ve had an RHC procedure experienced little to no pain and had an overall easy experience. One member said, “I was scared, too, but it wasn’t bad or painful at all.”

Another noted, “I had the right heart catheterization, and there was nothing to it. It was over before I knew it, and there was no pain whatsoever.”

Some members describe a bit of soreness from where the catheter was inserted in the neck or groin. One member said, “Only issue I had was a very sore neck.” Another shared, “I was somewhat sore in my groin after for a day or two.”

Overall, myPHteam members have described RHC as a painless and easy procedure. One member noted, “It’s easy peasy, especially if they use a vein in your arm. I was nervous with my first one, and now it’s no big thing.”

Another member said, “I had one Monday. There was no pain, and I got to come home after lying still for two hours. I worked myself up for nothing. It’s not a bad test at all.”

Members also value the information gained from RHC: “I like having them. It is the one true way to know how things are going in your heart.”

What Does Right Heart Catheterization Measure?

RHC gives your doctor a lot of information about the hemodynamics (blood flow) in your heart and lungs. This information can be used to determine how mild or severe your PAH is and what medications may work best for you. RHC is one of several tests to measure PAH disease progression, or how your disease is advancing.

Pressure Measurements

Mean pulmonary arterial pressure (mPAP) is an important measurement doctors use to determine whether a person has PAH. It measures the pressure in your pulmonary artery, which carries blood from the heart to the lungs. PH is indicated when mPAP is equal to or greater than 20 millimeters of mercury (mm Hg).

Doctors may measure pulmonary arterial wedge pressure (PAWP), also called pulmonary capillary wedge pressure, an estimate of the pressure in the left atrium of the heart. Doctors use the difference between mPAP and PAWP to determine how much of the pressure elevation in the lungs is due to abnormalities in the pulmonary arteries versus left-sided heart disease. This value can help diagnose PAH specifically.

Pulmonary Vascular Resistance

Pulmonary vascular resistance (PVR) is a measurement of the resistance of blood flow from the pulmonary artery to the left atrium. Blood should flow easily through the pulmonary arteries, but thickened arteries in PAH can increase the resistance to blood flow. PVR is measured in “Wood units.” A PVR of more than 2 Wood units is crucial for a PAH diagnosis.

Cardiac Output

Cardiac output measures how much blood your heart is able to pump in a minute. If your heart is weakened or failing, it may have a low cardiac output. Doctors can measure your heart’s output during RHC using thermodilution. With this technique, cold saline (a saltwater solution) is injected into the heart using the catheter. The catheter can detect the change in baseline blood temperature when the saline is injected. A computer uses the temperature change to calculate how much blood your heart is pumping.

Shunt Assessment

Measuring the cardiac output and amount of oxygen in the blood allows health care providers to see if there is a left-to-right shunt, or backflow of blood in the heart. A left-to-right shunt may be caused by a hole in the heart that allows blood from the left side of the heart to flow back into the right side. The increased amount of blood in the right heart increases pressure on the right side of the heart and the pulmonary artery.

Vasoreactivity Testing

During RHC, your doctor can inject (or have you inhale) different medications and measure how they affect your heart and pulmonary arteries. Vasodilators are medications that relax and dilate (open up) your blood vessels, lowering blood pressure and allowing better blood flow.

Is Right Heart Catheterization Safe?

Though RHC may sound scary, the procedure has a very low risk of complications in experienced facilities.

A cardiology study of more than 7,000 people with PH who received RHC in experienced centers across the United States and Europe found that only 1.1 percent of people had serious complications from the procedure. Other studies showed that the risk of RHC complication for people with PAH was higher for children or infants (under 2 years old) or people with more severe PAH (higher right atrial pressure).

There are some reasons someone should not have RHC, such as having:

• Mechanical or prosthetic valves in the heart
• Masses in the heart (such as tumors)
• Endocarditis (inflammation in the right side of the heart)

Your doctor will take your full medical history before RHC and explain the risk of complications. This is a good time to ask questions and discuss any of your concerns.

Right Heart Catheterization vs. Left Heart Catheterization

There are a couple of key differences between RHC and left heart catheterization, including where the catheter goes and what is measured.

As the name suggests, left heart catheterization involves inserting a catheter to look at the left side of the heart. The catheter is inserted into an artery, not a vein like in RHC, in the arm, wrist, or groin.

Whereas RHC measures pressure in the right atrium, right ventricle, and pulmonary artery, left heart catheterization does the following:

• Measures pressure in the left ventricle
• Looks for blockages in the coronary arteries, which supply blood to the heart
• Checks your aorta, which delivers oxygen-rich blood to the body, and your aortic valve

Left heart catheterization looks for issues with heart function in addition to heart defects, heart tumors, and cardiac valve disease.

Talk to People Who Understand

On myPHteam, the social network for people with pulmonary hypertension and their loved ones, more than 53,000 members come together to ask questions, give advice, and share their stories with others who understand life with pulmonary hypertension — including pulmonary arterial hypertension.

Have you had right heart catheterization? What was your experience like? Share your experience in the comments below, or share your story on your Activities page.