The Heart  
Heartbeat: Anatomy of the Heart

Copyright © Nucleus Medical Media, Inc.


Electrical signals in your heart make the heart muscles contract, pumping blood through your body. If the electrical signals are not flowing well through the heart, this can create serious problems.

An electrophysiology study is a test where electrode wires are passed through a blood vessel and into your heart. This electrode can record or create electrical activity. This can help find any problems with the flow of electricity in your heart.


Reasons for Procedure  

An electrophysiology study is performed to:

  • Find the cause of abnormally slow heart rhythms ( bradycardias )
  • Find the source of abnormally fast heart rhythms ( tachycardias )
  • Provoke and diagnose heart arrhythmias (irregular heartbeats) that occur infrequently
  • Reveal suspected arrhythmias

An electrophysiology study may also be used to assess:

  • Risk for sudden death
  • Symptoms of unknown cause
  • Response to anti-arrhythmic therapy
  • Need for a pacemaker
  • Need for an implantable cardioverter defibrillator
  • Need for cryoablation (destruction of some heart cells by freezing)

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

A person’s risk level is very individual. It may relate to the specific arrhythmia suspected and any underlying medical conditions.


What to Expect  

Prior to Procedure  

You doctor may order the following tests:

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

  • Aspirin or other anti-inflammatory drugs
  • Blood-thinning drugs, such as warfarin
  • Anti-platelet drugs, such as clopidogrel

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 monitor your heart rhythm during the test. An area on your thigh, neck, or just below your collarbone will be cleaned. A thin electrical wire will be inserted into a blood vessel in that area.

The electrode will be passed through the blood vessel and into your heart. Your doctor will be able to see the progress of the catheter with the help of x-rays on a screen. The tip of the electrode can send electrical signals to your heart. The signals will make the heart beat at different speeds. Your heart rhythm will be recorded to look for abnormalities. The tip of the electrode can also record electrical activity at specific spots in