Introduction

Electrical Conduction System of the Heart

Electrophysiology (EP) is a subspecialty of cardiology which examines the electrical behavior of the heart by recording electrical activity from within the heart chambers. Specially trained cardiologists use catheters inside the heart to evaluate certain symptoms a patient may be experiencing.  An EP study  enables a trained cardiologist to look for explanations for such symptoms as passing out or to evaluate certain arrhythmias (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.

The EPS Procedure

Preparing for the EP Study

Your doctor may advise you to stop taking certain medications before your EP study to ensure more accurate results. Prior to the EP test 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 see a video about the procedure, and 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.

The EP Study

Catheters Used for Electrophysiologic Evaluation

Hospital admission usually occurs the same day as your test. The EP lab is similar to the laboratory used for heart catheterizations. During the EPS procedure you will be awake, but you may be given a medication to help you relax. Electrodes will monitor your heart rhythm and rate. This may require that some areas be shaved in preparation. Prior to the test, an intravenous (IV) line will be started. Through it, your physician can administer medications or extra fluids you may need.

In preparation for the study, the groin area is sterilized and numbed so a catheter can be inserted. Through this sheath, temporary pacemaker catheters--about as thick as a piece of spaghetti-- are placed in strategic areas of the heart. These catheters record electrical activity inside the heart and allow the physician to artificially "pace" your heart. 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 physician will artificially create different heart rates and monitor for arrhythmias. During the test you may experience no symptoms whatsoever, or you may feel a rapid heart rate, skipped beats, light-headedness, chest pain or discomfort. If you experience any of these problems, please let the physician know. You may pass out briefly during the test. It may become necessary to give your heart a mild electric shock to restore your normal rhythm. When you wake up, you may find an oxygen mask covering your mouth and nose.

Usually complications from EP studies are minimal. Although the procedure may seem somewhat frightening, remember you are being safely monitored in the EP lab by a highly-trained team of doctors, nurses and technicians.

If no arrhythmia is found, the catheters are removed, the test is concluded, and you will be returned to your hospital room. During the procedure, if your physician is successful in reproducing your arrhythmia, he/she may administer a medication through your IV. The doctor will then check the drug's effectiveness. There are several types of medications that your physician may try before finding the right one for you. Everyone responds differently to these medications.

EP studies usually last from two 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.

Some patients may require no further treatment. Others may require any one of the treatment alternatives described below. Your physician will explain his/her 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

After the procedure, when you have returned to your room you will be given the following instructions:

1. To remain in bed with your leg straight for 3-4 hours. Nurses will assist you when it is OK to get up;
2. Keep your head on the pillow;
3. 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. If you notice a discharge, or feel feverish or become very uncomfortable, please call our office immediately.

Arrythmia Treatment Options

Anti-arrhythmic therapy

After diagnosis is made by EP study, drugs may be prescribed to prevent arrhythmias from recurring. To determine a drug's effectiveness, the EP study may be repeated.

Pacemaker Therapy

EP studies may reveal a conduction disturbance and demonstrate the need for a permanent pacemaker. 

The illustration shows how the pacemaker is implanted under the skin and the leads reach the heart through the subclavian vein.

Radio Frequency Ablation

In the past several years, 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.

The illustration shows a typical implantation of the device.

Medical Procedures