What is an Electrophysiology Study?

An electrophysiology study is a test that records the electrical activity and electrical pathways of your heart. This test is used to help reveal the cause of arrhythmias (abnormal heart rhythms), including atrial fibrillation, or AFib, and determine the best course of treatment.

In general, an EP study is performed after other noninvasive tests, such as an electrocardiogram (ECG), have been conducted. An EP study can provide more detail about your abnormal heart rhythm, including the cause of the arrhythmia, the evaluation of antiarrhythmic medications and the need for further treatment such as catheter ablation or device implantation (pacemaker or implantable cardioverter defibrillator, also called ICD).

What to Expect During an EP Study

Prior to an EP study, you will be given sedation through an IV line that will keep you comfortable and drowsy, but still breathing on your own. After injecting numbing medication, your doctor will insert catheters (thin, flexible tubes) into your groin and/or neck which are introduced into blood vessels and directed into the heart under X-ray guidance. The catheters detect the electrical activity in your heart and are used to assess your heart’s electrical system. The catheters are specially designed with a pacing mechanism that sends electrical signals to the heart to induce the arrhythmia. This is necessary to find the location of your arrhythmia and determine which treatment may be appropriate. Once the abnormal electrical pathways have been located, your doctor may administer different medications to evaluate their effectiveness at restoring normal rhythm.

Based on the findings of this study, your doctor may want to proceed with a device implant or an ablation. The entire EP study may last approximately two hours; however, if additional treatments are necessary, more time may be needed.

After the EP study, you will need to recline and hold your legs still (no bending at the waist) for several hours before your discharge in order to monitor the catheter insertion sites. If an ablation or device implantation is performed at the same time as the EP study, you will need to plan on staying in the hospital for at least one night.