An electrophysiology study (EP study) is a procedure in which a thin tube (catheter) is inserted into a vein or artery (e.g., in the groin) and guided to the heart, where it can perform highly specific measurements of the heart’s electrical activity and pathways. These measurements are particularly helpful in the diagnosis of abnormally fast heart rhythms (tachycardias) or abnormally slow heart rhythms (bradycardias). An EP study is typically performed only after other noninvasive tests, such as an electrocardiogram (EKG), have been performed.

The results of an EP study may lead to further treatment, such as the implantation of a pacemaker or implantable cardioverter defibrillator, or the prescription of antiarrhythmic medications. Because EP studies can pinpoint the source of abnormal electrical conduction rhythms, the physician may decide to perform a catheter ablation. This procedure destroys selected, abnormal areas of the heart’s conduction system, restoring the heart’s normal electrical activity. It is often performed in conjunction with the EP study.

If the physician does not need to do additional procedures (e.g., an ablation) during an EP study, then the patient can go home after about six hours. However, a hospital stay of up to 24 hours is usually necessary if additional treatments are performed during the EP study.