EP Study & Ablation

Electrophysiology Study

An EP (electrophysiology) study is a test of the heart's electrical system. During an EP study, your doctor looks for abnormal heart rhythms.

This test is often done on patients who are at risk for sudden cardiac death. Some patients who might be at risk include: those who have recently had a heart attack, have poor pumping function of their heart, or have a cardiomyopathy (enlarged heart). Other times this test is done because someone might have episodes of a very fast or irregular heart rate. 

This test is done in the cath lab. You will have an IV in place and several small catheters are placed in the groin area and advanced to your heart. The catheters are carefully placed along the heart wall. Special electrodes on the catheters can then detect the electrical pathways in the heart and create an electrical 'map' for your doctor to interpret. The test can take from 20 minutes to 1 hour and may be longer if treatment is needed.


Sometimes during an EP study, your physician may find an abnormal electrical pathway which needs ablation. Cardiac ablation is a minimally invasive procedure that does not require open heart surgery. In cardiac ablation, catheters (thin, flexible tubes) are threaded through the patient's blood vessels to reach the heart and disable (ablate) abnormal heart tissue. Cardiac ablation may be used to treat Atrial Fibrillation and Supraventricular Tachycardia (SVT). SVT includes AV nodal re-entry and Wolf-Parkinson-White. The abnormal tissue, or pathway, is identified and then high frequency radio waves are used to destroy the pathway. Once the abnormal pathway is ablated, normal conduction can take over and restore a normal rhythm.

EP Test & Ablation Frequently Asked Questions

How do I prepare for an EP Study or Ablation?

When your electrophysiology study is scheduled, you will be given very specific instructions. Most likely you will be asked to have nothing to eat or drink after midnight the night before the procedure. You should take your medication with you to the hospital and should be prepared to spend the night.

What can I expect after the EP Study or Ablation?

You will be asked to limit lifting for several days. The groin area may be a little tender but should not be very painful. You should contact your physician if you notice any swelling or bleeding from the site. You may have been started on a new medication in the hospital to help you maintain a normal rhythm. It is very important that you communicate with your provider and are very clear about which medications you should take after you are discharged.