An electrophysiology study is an invasive test your provider uses to examine the electrical signals happening in your heart. Catheters or tubes that go through a vein and into your heart help your provider see where abnormal heart signals start. This helps them diagnose your arrhythmia, or abnormal heart rhythm, and decide on a treatment.
An electrophysiology (EP) study is a detailed evaluation of the electrical activity in your heart. Your healthcare provider uses cardiac catheters (small tubes) and computers to make electrocardiogram (EKG) tracings and electrical measurements from inside your heart.
Studying your heart’s electrical activity can tell your provider where something is going wrong with your heartbeat signals. Normally, signals that tell your heart to beat travel the same route in an organized way every time.
When you have an abnormal heart rhythm, it’s like a bus that isn’t following its normal route. The bus may start the route at the wrong bus stop, skip a stop or not travel the full route, for example. Or it could be going too fast or too slow. Irregular signals can be like this and your provider wants to find out why.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
During your electrophysiology test, your cardiologist may safely reproduce your abnormal heart rhythm (also called arrhythmia or dysrhythmia). Then they’ll give you medications to see which one works best to control your irregular rhythm.
Your electrophysiological study can give your healthcare provider information about your abnormal heart rhythm such as:
Your provider may recommend an electrophysiology study when other tests can’t provide enough information to thoroughly evaluate your abnormal heart rhythm.
You may have already tried these tests:
You can prepare for your electrophysiology study in these ways:
Follow these medication tips when preparing for your electrophysiology study:
Prepare for your electrophysiology test in these ways:
Guidance on what you should wear on the day of your electrophysiology test:
Your study will take place in a special room called the electrophysiology laboratory, EP lab or catheterization lab.
After you lie in a bed, your healthcare provider will:
You’ll receive medication through an IV (intravenous line) to help you relax and make you feel drowsy. However, you won’t be asleep during your electrophysiology test.
The EP study takes one to four hours.
Your healthcare team will use several monitors so they can check your heart rhythm and blood pressure throughout your procedure.
Your healthcare provider will:
Tell your provider about any symptoms you feel during your electrophysiology study. If an abnormal heart rhythm happens, your provider may give you medications through your IV to test their effectiveness in regulating it. If you need it, your provider can send a small amount of energy through the patches on your chest to bring your heart back into a normal rhythm.
You shouldn’t feel pain during your EP study because you’ll receive medicine to keep you comfortable. However, you might feel pressure where the catheters went into your skin.
After your electrophysiological study, your healthcare provider will remove the catheters from your groin, arm or neck and apply pressure to the site to prevent bleeding. You’ll:
An electrophysiology test is generally a very safe procedure. However, as with any invasive procedure, there are risks. These may include:
Cardiologists and nurses who specialize in electrophysiology will perform the procedure in the controlled environment of an electrophysiology laboratory. They’ll take special precautions to decrease these risks.
Talk to your provider about any concerns you may have about the risks and benefits of the procedure.
Yes, electrophysiology studies are safe. The risk of an EP study being fatal is one in 5,000.
Your healthcare provider will explain the type of abnormal heart rhythm you have and how to treat it. They’ll also decide if you need treatment for your abnormal heart rhythm, which may include:
Your provider may decide to give you some of these treatments during or right after your electrophysiology study.
You’ll get preliminary test results after the procedure. Based on these results, your healthcare provider will decide if you can go home or will need to stay in the hospital. They may want you to make an appointment with them to talk more about your electrophysiology study results and treatment.
Contact your doctor if you have:
Call 911 instead of your doctor if you have:
A note from Cleveland Clinic
Having an electrophysiology study may seem like a bigger deal than the other heart tests you’ve had, but your healthcare provider scheduled it for a reason. They want to find out what’s happening in your heart so they can help you. Although an electrophysiological study is invasive, it’s a safe test that will give your provider the information they need to fix your abnormal heart rhythm. Your healthcare team will make sure you’re comfortable during your electrophysiology test.
Last reviewed by a Cleveland Clinic medical professional on 05/13/2022.
Learn more about our editorial process.