An EP study or electrophysiology study of your heart is a test that looks at your heart’s electrical activity. A healthcare provider uses this information to diagnose and treat abnormal heart rhythms. This invasive test uses catheters that go into your heart to capture its signals. In some cases, providers can fix the problem during the EP study.
An electrophysiology study (EP study) is a detailed analysis of the electrical activity in your heart. Electrophysiology (EP) is a subject within cardiology that analyzes your heart’s electrical signals to diagnose and treat abnormal heart rhythms (arrhythmias).
Your healthcare provider uses cardiac catheters (small tubes) and computers to make electrocardiogram (EKG) tracings and electrical measurements from inside your heart. Sensors a provider places inside your heart provide more information than you can get from electrodes outside your chest.
Studying your heart’s electrical activity can tell your provider if and 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. Or it could be going too fast or too slow. Irregular signals can be like this. Your provider wants to find out why to determine whether the rhythm is dangerous and how to treat it.
An electrophysiology lab is like a place for detective work. An electrophysiologist is an expert at understanding heart rhythms. They can make sense of the data from an electrocardiogram (EKG). Each of the waves on an EKG screen says something about what various parts of your heart are doing.
Electrophysiologists spend many hours studying the various EKG waves and what they should look like. They also get to know what it means when a certain wave looks different. They pay close attention to where an abnormal rhythm starts and ends on an EKG display or printout.
They can come up with a theory about what’s wrong and then test their theory in the EP lab. Using equipment and medicines like adenosine or isoproterenol, they can make your heart beat faster or slower and examine the results.
Electrophysiologists follow a logical plan for what they want to check instead of relying on what looks like an obvious answer. The information they gather may lead them to several possible diagnoses. Testing helps them narrow down the options until they can be sure they have the right diagnosis.
Your EP study can give your healthcare provider information about your abnormal heart rhythm, such as:
Your provider may want to do an EP study when other tests can’t provide enough information about your abnormal heart rhythm.
You may have already tried these tests:
Depending on your condition, an electrophysiologist can use the information from an EP study to treat you with catheter ablation right away. They can do this through the catheters already in place in your heart for the study.
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During your electrophysiology test, your cardiologist may safely reproduce your abnormal heart rhythm by using a catheter or medications. They can use a catheter to help determine where the rhythm is within your heart. Then they can use this information to guide what medications to use to treat it or whether to perform an ablation.
You can prepare for your electrophysiology test in these ways:
Follow these medication and food tips when preparing for your electrophysiology study:
Your study will take place in a special room called the electrophysiology lab, EP lab or catheterization lab.
After you lie in a bed, your healthcare provider will:
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 how well they regulate 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.
Your healthcare team will use several kinds of equipment throughout your procedure. These include:
After your electrophysiology 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, but it has risks. These may include:
Your providers will perform the EP study in a controlled environment. They’ll take special steps to decrease your risks.
Talk to your provider about any concerns you may have about the risks and benefits of the procedure.
An EP study can:
Yes, electrophysiology studies are safe. The risk of an EP study being fatal is 1 in 5,000.
Your healthcare provider will explain the type of abnormal heart rhythm you have. They’ll also decide if you need treatment for your abnormal heart rhythm, which may include:
You’ll get preliminary test results right 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.
Your provider may be able to fix your issue right away with catheter ablation. If not, they’ll need to schedule other procedures or prescribe medicine for you. Even after a catheter ablation, some people need other forms of treatment, like a pacemaker.
Contact your healthcare provider if you have:
Call 911 or your local emergency number if you have:
You’ll get medication through an IV line to help you relax and make you feel drowsy. But you won’t be asleep during your electrophysiology test.
An EP study takes one to four hours.
You shouldn’t feel pain during your EP study because you’ll receive medicine to keep you comfortable. But you might feel pressure where the catheters went into your skin.
Researchers started recording the heart’s electrical signals from inside the body in the late 1960s. From there, they began to map problem areas and target them with ablation.
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 EP study is invasive, it’s a safe test that’ll 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 11/21/2023.
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