What is an EP study?
An electrophysiology (EP) study is a test of your heart’s electrical system. While an electrocardiogram (ECG) gives an overview of your heart’s electrical system, the EP study gives a more in-depth view. The test helps find out details about abnormal heart rhythms, called arrhythmias. The EP study can reveal:
- If you have an arrhythmia
- The cause of the arrhythmia
- Where the arrhythmia begins in the heart
- If you are at risk for sudden cardiac arrest (SCA)
- The best treatment for an arrhythmia
The EP study begins when one or more leads are inserted into a blood vessel, usually in the groin. The doctor gently “steers” the leads toward your heart. Once in place, the leads sense your heart’s electrical activity. One special lead also delivers electrical signals to your heart to trigger an arrhythmia. That’s to help find out how easily your heart can produce arrhythmias on its own. During the EP study, your doctor closely monitors your heartbeats. If an arrhythmia occurs, the doctor treats you with:
- Medications given through the intravenous (IV) line in your arm or hand
- Electrical signals delivered to the outside of your chest through patches
In some cases, ablation (a form of treatment) is done at the same time as your EP study. (To learn about ablation, go to the Procedures part of the Medications & Procedures section.) Or your doctor can suggest other types of treatment after the EP study.
What can I expect?
Your test will be performed in a “cath lab.” You undress, put on a hospital gown or sheet, and lie on an exam table. An intravenous (IV) line put into your arm delivers fluids and medications during the test. The medication makes you groggy, but not unconscious. Patches called electrodes are put on your chest. The electrodes monitor your heart’s electrical signals during the test. A blood pressure cuff on your arm also regularly takes your blood pressure.
The doctor makes a small incision (usually in the groin) for the catheter. The groin area will be numbed so you shouldn’t feel pain, but you may feel some pressure as the catheter is inserted. If the doctor delivers electrical signals to your heart, you might feel your heart racing or pounding. You won’t be fully asleep, so during the test your doctor or nurse might ask you questions. Afterwards you may be in the hospital overnight, but most people have a fairly