by Scholten A


An electrophysiology (EP) study is a test of the electrical system of the heart. It can check for problems with rhythm of heartbeat.

Electrical signals coordinate the different parts of the heart. This keeps blood flowing the way it should.

The Heart
Heartbeat: Anatomy of the Heart
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Reasons for Procedure

Changes in electrical signals can make it hard for the heart to works as it should. This can lead to minor and major problems. An EP study may be done to:

  • Find the cause of abnormally slow heart rhythm— bradycardia
  • Find the source of abnormally fast heart rhythm— tachycardia
  • Provoke and diagnose infrequent heart arrhythmias
  • Reveal suspected arrhythmias

An electrophysiology study may also be used to assess:

Possible Complications

Problems from the procedure are rare, but all procedures have some risk. Your doctor will review potential problems, like:

  • Excess bleeding
  • Infection
  • Blot clots
  • Injuries to blood vessels or the heart
  • Abnormal heart rhythm
  • Heart attack

What to Expect

Prior to Procedure

You doctor may order the following tests:

  • Blood tests
  • ECG to record the heart's electrical activity
  • Chest x-ray

Talk to your doctor about any medications, herbs, or supplements you are taking. You may be asked to stop taking some medications up to 1 week before the procedure.

Do not eat or drink anything after midnight the day before your surgery, unless told otherwise by your doctor.


A local anesthetic will be given by needle. It will numb the area where the catheter will be inserted. You will also receive a mild sedative through an IV in your arm. This will help you to relax during the test.

Description of the Procedure

You will be asked to lie down on an examination table. Electrodes will be placed on your chest. The electrodes will help to track your heart rhythm during the test. An area on your thigh, neck, or just below your collarbone will be cleaned. A thin wire will be inserted into a blood vessel in that area. The wire will be passed through veins until it reaches the heart. A special x-ray will let the doctor see where the wire is in the body as the wire is being moved.

The electrodes on the chest will measure the heart’s electrical signals. The next steps will depend on the reason for your EP study. The doctor may send signals through the wire to stimulate the heart. It may start an abnormal rhythm. This will help the doctor see what areas of the heart may be causing a problem. The doctor may also be able to see if medicine is working as it should. A specialists may map the heart’s electrical movement during each beat. This can help to find the source of an abnormal heartbeat.

How Long Will It Take?

The length of the test will vary based on what your doctor is investigating. The test may take 2 to 4 hours or more to complete.

Will It Hurt?

You may feel some pressure at the insertion site. It will feel bruised and tender for a few days.

You may feel palpitations, shortness of breath, or chest discomfort if an abnormal rhythm was started. You may even lose consciousness. The medical team can usually control abnormal rhythms with medicine. A shock may be needed to stop some rhythms. You will receive more sedation so that you do not feel pain.

Post-procedure Care

You may be able to go home after about 6 hours. You may need to remain in the hospital for up to 24 hours if additional procedures are done during the study.

At the Care Center
  • ECG and blood studies may be done.
  • You will likely need to lie still and flat on your back for a period of time. A pressure dressing may be placed over the area where the catheter was inserted to help prevent bleeding. It is important to follow directions.
  • You will need to rest in bed until the sedative has worn off. Your heart rate and blood pressure will be monitored. You will also be checked for swelling or infections. If necessary, you may be given pain medication. After resting for at least 4-6 hours, your doctor will let you know if you can go home that day or if you need to be admitted for more treatment or observation. If you are discharged on the same day as the test, you should have someone drive you home.

The results of the study may be available before you leave the hospital or in the next few days. Your doctor will notify you if you need any treatment.

At Home

When you return home, avoid lifting heavy objects. Do not engage in strenuous exercise or sexual activity until your doctor clears you to do so.

Call Your Doctor

Call your doctor if any of the following occur:

  • Signs of infection, including fever and chills
  • Redness, swelling, increasing pain, excessive bleeding, or any discharge from the insertion site
  • Cough, shortness of breath, or chest pain
  • Your leg feels cold, turns white or blue, or becomes numb or tingly
  • Lightheadedness or weakness

If you think you have an emergency, call for emergency medical services right away.


American Heart Association 

Texas Heart Institute 


Heart and Stroke Foundation of Canada 

University of Ottawa Heart Institute 


Electrophysiology studies (EPS). American Heart Association website. Available at: Accessed January 26, 2021.

Electrophysiology studies. Texas Heart Institute website. Available at: Accessed January 26, 2021.

Warning signs of a heart attack. American Heart Association website. Available at: Accessed January 26, 2021.

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