Electrophysiology Study
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Electrophysiology Study


En Español (Spanish Version)


An electrophysiology study is a procedure that examines the heart’s electrical activity and pathways.

The Heart

Heartbeat: Anatomy of the Heart

© 2008 Nucleus Medical Art, Inc.

Parts of the Body Involved

  • Artery in the leg or groin
  • Upper chambers of the heart (atria)
  • Lower chambers of the heart (ventricles)
  • Sinoatrial node of the heart

Reasons for Procedure

An electrophysiology study is performed for the following reasons:

  • Diagnose the source of abnormally slow heart rhythms ( bradycardias )
  • Diagnose the source of abnormally fast heart rhythms ( tachycardias )
  • Provoke and diagnose heart arrhythmias that occur infrequently
  • Reveal suspected arrhythmias
  • Evaluate a person’s risk for sudden death
  • Assess symptoms of unknown cause, including:
      • Chest pain
      • Shortness of breath
      • Fatigue
      • Dizziness/fainting ( syncope )
  • Assess your response to anti-arrhythmic therapy, or your need for a pacemaker or implantable cardioverter defibrillator

Risk Factors for Complications During the Procedure

The risk of complications during the procedure is low. A person’s risk is very individual and may relate to the specific arrhythmia suspected along with the underlying medical condition.

What to Expect

Prior to Procedure

Follow your doctor’s instructions. Do not drink or eat anything after midnight the night before, or at least six hours before you take the test. Talk to your doctor about what medicines you’re taking. You may have to stop taking certain medications before the procedure. You will probably have blood tests, an electrocardiogram , and a chest x-ray taken before the procedure.

During Procedure

You will be asked to lie down on an examination table. Electrodes will be placed on your chest. The electrodes have wires that are hooked up to an electrocardiogram machine, which monitors your heart rhythm during the test. You will be shaved and cleansed around the area (usually the thigh, neck, or just below the collarbone) where the thin tubes (catheter) will be inserted. You will receive a mild sedative through an intravenous line (IV) in your arm, which will help you to relax during the test.


A local anesthetic will be given by needle to numb the area around where the catheters will be inserted.

After Procedure

After the procedure, you will need to rest in bed until the sedative has worn off. Your heart rate and blood pressure will be monitored, and you will be checked for swelling or infections. You may be given pain medications, if necessary. 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.

Description of the Procedure

Catheters will be gently threaded through the artery and into your heart with the help of x-rays on a television screen. Electrodes located at the end of the catheters send electrical signals to your heart to make it beat at different speeds. These electrodes also receive electrical signals from your heart, so that your heart rhythm can be recorded to assess the presence of abnormalities.

How Long Will It Take?

The length of the test will vary based on what arrhythmia your doctor is investigating, and whether he or she needs to test your response to several medications. In general, the test may take two, four, or even more hours to complete.

Will It Hurt?

You may feel some mild discomfort with the initial injection. Also, as the doctors induce an arrhythmia, you may feel palpitations, shortness of breath, chest discomfort, or you may even lose consciousness. The medical team can usually control arrhythmias with medications, but they may need to administer an external shock to stop some rhythms. If they need to do this, you will receive more sedation.

Possible Complications

In general, the risk of complications is low. There is a small risk of bleeding and/or infection at the site of catheter insertion. Rare complications may include:

Average Hospital Stay

If your doctor does not need to do additional procedures, you may be able to go home after about six hours. However, you may need to remain in the hospital for up to 24 hours if additional procedures are performed during the study.


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.

Call Your Doctor If Any of the Following Occurs

  • Your symptoms persist or worsen
  • You develop new symptoms


American Heart Association

Texas Heart Institute


Heart and Stroke Foundation of Canada

University of Ottawa Heart Institute



HeartCenter Online website. Available at: http://www.heartcenteronline.com . Accessed November 22, 2004.

North American Society of Pacing and Electrophysiology website. Available at: http://www.hrspatients.org/patients/heart_tests/electrophysiology_study.asp . Accessed November 22, 2004.

Texas Heart Institute website. Available at: http://texasheartinstitute.org/ . Accessed November 22, 2004.

Last reviewed November 2007 by J. Peter Oettgen, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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