Electrophysiology Study

What is Electrophysiology?
Electrophysiology (EP) is a subspecialty of cardiology that examines the electrical behavior of the heart by recording electrical activity from within the heart chambers. Specially trained cardiologists (called electrophysiologists) use catheters inside the heart to evaluate certain symptoms a patient may be experiencing. EP studies enable the doctor to look for explanations for such symptoms as passing out or to evaluate certain arrhythmias (too fast, too slow or irregular heart beats). Patients may need to have an EP study after surviving a cardiac arrest or heart attack. Another reason might be ECG (EKG) findings that may place them in a high-risk category.

Preparing for the EP study.
Your doctor may advise you to stop taking certain medications before your EP study to ensure more accurate results. If you have any questions about any other medications be sure to ask. Prior to the EP study a pre-admission visit will be scheduled so a chest x-ray, electrocardiogram (ECG) and blood work can be obtained. During this visit, you will be able to ask questions, or express any concerns you may have. EP studies require that you have an empty stomach. In most cases you will not be permitted to eat or drink anything after midnight. It's important to get a good night's sleep.

Hospital admission usually occurs the same day as your test. You will be asked to remove all clothing and jewelry and to put on a hospital gown. The nurse will need to start an intravenous (IV) line for fluids and medications. When it is time for your procedure the EP Lab staff will explain the procedure to you and answer any questions you may have. During the EP procedure you will be awake, but will be given medications to help you relax. Staff members present for the procedure are a scrub technician or scrub nurse, and a nurse to monitor and care for your needs. The Electrophysiologists will perform the study. 

During the examination
The staff will position you on the exam table and connect you to a blood pressure cuff and an oxygen monitor. A R Lead ECG monitor will be applied. This may require that some areas be shaved in preparation. The Electrophysiologist will administer a local anesthetic and then make a small nick in your skin so that a catheter can be inserted. Through this sheath, temporary pacemaker catheters (about the size of a piece of spaghetti) are placed in strategic areas of the heart, although you may not feel the catheters as they are being placed. These catheters record electrical activity inside the heart and allow the physician to artificially "pace" your heart. For some EP procedures the side of the neck is also sterilized and numbed so a catheter can be inserted. An x-ray machine will be placed directly over your body to allow the physician to watch the catheters and see that they are properly placed. You will receive only intermittent low doses of x-rays. The physicians will artificially create different heart rates and monitor for arrhythmias. During the test you may experience no symptoms whatsoever, or you may feel your heart beating at different speeds.

What does the test show?
If no arrhythmia is found, the catheters are removed, the test is concluded, and you will be returned to a hospital room. 

If your physician is successful in reproducing your arrhythmia you may need one of the following treatment options. 

Treatment options

  • Medication: after diagnosis is made by EP study, drugs may be prescribed to prevent arrhythmias from recurring.
  • Pacemaker Therapy: EP studies may reveal a conduction disturbance and demonstrate the need for a permanent pacemaker.
  • Radio Frequency Ablation: radio frequency ablation (RFA) has become the treatment of choice for specific rhythm disturbances. High frequency radio waves use thermal heat to burn and eliminate the precise location in the heart from, which an arrhythmia originates.
  • Implantable Cardioverter Defibrillator: An implantable cardioverter defibrillator is a miniature implantable device that monitors the heart rate and in life threatening situations administers a shock to the heart to restore normal rhythm.


Post examination information
EP studies usually last from three to four hours. After the catheters are removed, pressure will be applied to the puncture site just long enough to stop the bleeding. No stitches are required but a sterile dressing will be applied and can be removed the next day. Your physician will explain the findings and recommendations following your study. However, don't be afraid to ask questions at any time before, during or after the procedure! After the EP study you will be transferred to a room and you will be given the following instructions:

  • Remain in bed with your leg straight for 4-5 hours; nurses will assist you when it is OK to get up.
  • Keep your head on the pillow.
  • Inform the nurse if you have any warmth, pain or swelling where the catheters were removed.
  • You will be permitted to eat and drink.
  • Your vital signs and catheter insertion site will be checked frequently.


Going home
The exact length of your hospital stay is determined by your diagnosis and the treatment option prescribed by your physician. A normal EP study usually requires only a one night stay in the hospital. ‘When the bandages are removed from the catheter insertion site, you may notice a small bruise no larger than a quarter. You may also feel a small lump there. The bruise may become slightly larger and/or darker after you return home. Both of these are part of the body's natural healing process and should disappear completely within two weeks. Call your doctor if you have any bleeding, or signs of infection (redness or oozing) at the insertion site. 

What are the risks?
There can be some risk involved with certain diagnostic procedures. These risks will be discussed by your physician prior to the procedure.