An electrocardiogram (also called an EKG or ECG) is one of the tests that can be used to diagnose pulmonary hypertension (PH). PH is a condition in which the pressure in the blood vessels between the lungs and heart (pulmonary arteries) is abnormally high.

If you’ve experienced shortness of breath or chest pain, your doctor may recommend that you undergo an electrocardiogram to help identify the cause of your symptoms. Electrocardiograms measure the electrical activity of the heart. This test reveals the position and size of the chambers of the heart, any damage to the heart, and the rate and rhythm of heartbeats.

Here is what you need to know about electrocardiograms for PH, including what EKGs involve, how the tests are performed, and what the results can reveal to your health care team.

What Is Electrocardiography?

Electrocardiography records the electrical signals in the heart. This record is called an electrocardiogram. EKG tests are noninvasive and painless — in fact, some smartwatches and other devices offer EKG monitoring. EKG testing can quickly identify heart problems while monitoring the heart’s health.

During an EKG test, small adhesive patches called electrodes are applied to specific locations on the skin of the abdomen and chest. These electrodes are connected by wires to the EKG machine. The machine then measures, records, and prints a record of heart activity on graph paper. The information shown in the report can include how irregular or steady the rhythm of heartbeat is, how fast the heart is beating, and the timing and strength of each electrical impulse.

An EKG may be done at a clinic, through a Holter monitor, or through an event monitor. Portable monitors work just like an EKG machine at a doctor’s office. Electrodes applied to your skin have wires that connect to a monitor. You can take the monitor with you to record for longer periods of time.

A Holter monitor is a portable device used to record the heart’s electrical activity continuously — over 24 to 48 hours or longer — when a person is away from their doctor’s office.

An event monitor is a portable device that records the electrical activity of the heart when a person shows symptoms of a potential heart condition or disease. The device records the same information as an EKG used at a doctor’s office or hospital, but it does so over a longer period of time. An event monitor can typically transmit the information directly to the health care provider. This lets the provider read and analyze the heart’s electrical activity while the person is experiencing symptoms.

How Are EKGs Used for Pulmonary Hypertension?

EKGs are one of the tools that can help a health care team diagnose PH. Specifically, an EKG may be used to detect or determine:

• If narrowed or blocked arteries in the heart are causing problems like chest pain
• Whether you have arrhythmias (abnormal heart rhythms)
• How well pacemakers or other treatments are working
• If you’ve had a previous heart attack
• If you have ischemia (poor blood flow leading to the heart muscle)
• If you have other heart abnormalities, such as abnormal electrical conduction or enlargement of a heart chamber

In a person with PH, an EKG may show signs of right ventricular hypertrophy (enlargement of the heart’s right ventricle). The higher a person’s pulmonary artery pressure, the more sensitive the EKG will be.

Normal pulmonary artery systolic pressure is 20 mmHg or lower, and normal pulmonary artery pressure is 12 mmHg. In PH, pulmonary arterial pressure is greater than 20 mmHg. This pressure is based on measurement with an echocardiogram. An echocardiogram is usually the first diagnostic test used to diagnose PH, but an EKG may point to PH and lead to further testing.

If your health care provider is uncertain about the cause of your symptoms, they may recommend other testing. They may ask that you use a Holter monitor, event monitor, or other kind of portable EKG monitoring device.

Can an EKG Conclusively Diagnose PH?

EKGs can help your doctor diagnose PH, but EKGs alone don’t give your doctor enough information to diagnose PH. Doctors will likely order additional tests to evaluate the health of your heart, lungs, and pulmonary arteries.

Other tests that can be used to diagnose and determine the cause of PH include:

• Cardiac catheterization
• CT scans
• MRI scans

If your health care team suspects PH, they will typically schedule a right-heart catheterization following an EKG and other specialized tests. Right-heart catheterization measures the blood pressure in the pulmonary arteries directly.

What To Expect on the Day of Your EKG

Knowing what to expect from a medical procedure can help calm any nerves you may have. Ask your doctor about any details you’re unsure of or nervous about.

Preparing for the EKG

There are no special preparations you need to make before having your electrocardiogram test. There are no restrictions on your eating or drinking, but clinicians will recommend that you don’t smoke right before getting the test. You should not wear any jewelry, but if you do, make sure that it is easy to remove. You may also want to wear loose, comfortable clothing to your appointment because you may be asked to put on a medical gown.

During the EKG Procedure

The EKG itself is painless. It’s noninvasive, so nothing will be injected into your body. The test itself will only take five to 10 minutes.

Adhesive electrodes will first be applied to your body. If you have hair on your body that will interfere with the electrodes, the health care professional will shave the area. Then they will apply 12 to 15 electrodes total to your chest, arm, and leg areas. They will keep your body covered while applying the electrodes. Sensors in the electrodes will detect and record your heart’s electrical activity. You should lie still while the results are recorded on graph paper.

Results of Electrocardiograms

A doctor will interpret the results of your EKG. The process of reading the graph is complex, but the basic wave pattern consists of three waves: the P wave, the QRS wave complex, and T waves. The doctor interpreting your results will compare them to a baseline (“normal”) EKG and an EKG of a person with PH. In a person with PH, the EKG may show signs of right ventricular hypertrophy, which will affect the height of certain waves known as R waves.

Your doctor will let you know once the results of your EKG are available. If they detect any abnormalities that may point to PH (or another condition), they may recommend undergoing another diagnostic test or a pulmonary function test in a follow-up appointment.

Find Your Team

On myPHteam, you’ll meet other people with pulmonary hypertension, as well as their loved ones. Here, members who understand life with PH come together to share support, advice, and stories from their daily lives.

Have you undergone an EKG for PH? Share your experience, thoughts, or tips in the comments below or by posting on myPHteam.