An electrophysiology (EP) study is an invasive test of the electrical system of the heart to help diagnose if there is an abnormal heart rhythm problem. It is performed by a heart rhythm expert, called an electrophysiologist. The electrical system of the heart is the part of the heart that coordinates the beating of the heart muscle. Through the leg vein, electrode catheters (long wires) are positioned inside your heart using X-ray guidance. These electrode catheters are used to evaluate the electrical system of the heart to see if there is a problem with the heart rate going too slow (bradyarrhythmia or bradycardia) or too fast (tachyarrhythmia or tachycardia).

If you are experiencing symptoms such as fainting, episodes of almost fainting, sensations of rapid heartbeats or excessively slow heartbeats, your physician may recommend an electrophysiology study. Your electrophysiologist will make a diagnosis based on the results of your study. If you are found to have a heartbeat that is too fast, you may be a candidate for catheter ablation. Your physician will also be able to determine if you are a candidate for a pacemaker or implantable cardioverter defibrillator based on the results of your electrophysiology study.

Why choose Ohio State for electrophysiology study?

The Electrophysiology Section at Ohio State’s Ross Heart Hospital consists of the largest group of electrophysiologists in central Ohio as well as more than 100 nursing staff members dedicated to the care of patients with heart rhythm problems. The Ross Heart Hospital is home to the largest electrophysiology program in Ohio, and one of the highest volume programs in the nation.

What to expect during an electrophysiology study

Preparing for your procedure

You will be asked to not eat or drink anything other than water for a period of time before the test, often starting at midnight the night before your test. Your physician will give you specific instructions on which medicines, if any, you should stop taking before the test. If you are not given specific instructions, please take your medicines as you normally would.

On the day of your electrophysiology study, a nurse will start an intravenous (IV) line. The IV line is placed so the doctors can give you medicine during the test if needed. Your nurse will also shave an area over your groin. This is where your doctor will put the tubes (catheters) and wires during your test.

Although you will be given a general time for your test, you may be taken at any time during the day. The time will depend on how many patients are scheduled, how long each test takes and if there are any emergencies.

During your procedure

The study is done while you are sedated to a comfortable state, but you will not be under general anesthesia unless ordered by your doctor. You will be helped onto the X-ray table and the nurses will prepare you for the procedure by placing adhesive pads on your chest and legs. A large sterile sheet will be placed over you from your neck to your toes. Your electrophysiologist will then insert catheters (flexible tubes) or pacing wires into the blood vessel in the groin area. Local medicine is injected to eliminate the discomfort when placing the catheters.

Your electrophysiologist will position the pacing catheters into the heart using X-rays to guide positioning of the catheters. These catheters allow recording and testing of your heart’s electrical system.

Your test may be brief or a few hours. Your electrophysiologist will do the test as quickly and as safely as possible while obtaining all of the information needed.


The results of the electrophysiology study may indicate a need to implant a pacemaker to treat a slow heart rhythm or to treat a rapid heart rhythm from the bottom chamber of the heart with an implantable cardioverter defibrillator.

For some patients, the electrophysiology study may reveal a rapid heart rhythm problem from the top chamber of the heart, called paroxysmal supraventricular tachycardia.

Paroxysmal supraventricular tachycardia is often managed with radiofrequency catheter ablation. This is a technique that delivers radiofrequency energy through the tip of the catheter that is positioned at the site of origin of the paroxysmal supraventricular tachycardia. The radiofrequency energy creates an irreversible lesion in the heart so to permanently eliminate the paroxysmal supraventricular tachycardia.

The initial part of the ablation procedure is to map and find the origin of the paroxysmal supraventricular tachycardia. This process may include the use of advanced technology that allows 3-D mapping of multiple heart chambers. Once the site of origin of the paroxysmal supraventricular tachycardia is found, the ablation lesion can be created using radiofrequency energy. Ohio State’s Ross Heart Hospital offers advanced ablation technology that includes use of large tip radiofrequency catheters, cooled-tip radiofrequency catheters, pulsed-energy radiofrequency ablation and cryo-ablation energy. Radiofrequency ablation is often quite successful, with a success rate of about 96-98 percent.

After your procedure

When the test is over, the catheters and wires will be removed. Pressure will be placed over your blood vessels to stop any bleeding. To prevent bleeding, you will need to be in bed and have your leg straight for about 3-4 hours. You will be told when you may get up. If you need to use the bathroom during this time, please ask the nurse for help.

Your nurse will check the areas where the catheters were placed, your pulse and your blood pressure several times. You will be able to eat and drink after your procedure. Your doctor will decide when the IV will be stopped.

Right after the test, your doctor will talk with you and your family to review the results and the plan of care for you and will relay this information to your physician.

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