What is Electrophysiology Study (EP)?
Electrophysiology Study (EP) is an invasive medical procedure performed to diagnose and evaluate arrhythmias by examining the heart’s electrical system. During the EP procedure, a map of the electrical system in the heart is created. This allows for precise detection of the source of arrhythmia. Abnormal electrical signals can be triggered through catheters placed in the heart chambers, and the origin of the arrhythmia can be accurately determined. This detailed information allows for creating a patient-specific treatment plan.
Why is Electrophysiology Study (EP) Performed?
EP study is performed to determine the type, source, and cause of arrhythmias, to plan treatment options, and in some cases to apply treatment in the same session. The procedure is particularly preferred in the following situations:
- To identify the cause of persistent or recurring heart palpitations
- To evaluate unexplained heart arrhythmias accompanied by loss of consciousness (syncope)
- To determine underlying rhythm problems in patients who have experienced sudden cardiac arrest
- To test whether medications used in arrhythmia treatment are effective
- To evaluate whether ablation therapy is necessary
- To determine the necessity of pacemaker or ICD (implantable cardioverter defibrillator) implantation

How is Electrophysiology Study (EP) Performed?
Electrophysiology study is performed in a sterile environment, usually in an angiography laboratory. During the procedure, the patient receives local anesthesia, and sedative medication can be administered if necessary. A thin catheter is inserted through the femoral vein in the groin and advanced into the heart. These catheters are placed in different regions of the heart, and electrical activities are recorded. The electrodes provide detailed information about the heart’s electrical conduction system, and signals can be sent to trigger arrhythmias.
The procedure typically lasts between 30 minutes to several hours. If abnormal rhythms are detected, ablation therapy can also be performed in the same session. After the procedure, patients usually require 4-6 hours of bed rest. Most patients can be discharged the same day or the next day. This period may be longer in complex ablation procedures. After discharge, it usually takes 1-2 weeks for patients to return to their normal activities.
EP study cannot be performed on every patient. It is not performed in cases such as active infection, presence of intracardiac clot, uncontrolled bleeding disorders. Conditions such as pregnancy, severe heart failure, and severe kidney failure require risk assessment.
How Long Does an Electrophysiology Study (EP) Take?
The electrophysiology study procedure typically lasts between 30 minutes to several hours. The duration varies depending on the type of arrhythmia being examined, the complexity of the procedure, and whether additional treatment methods such as ablation need to be applied. For example, an EP study performed solely for diagnostic purposes may take less time, while procedures combined with treatment may take longer.
What are the Risks of Electrophysiology Study (EP)?
While electrophysiology study (EP) is generally a safe procedure, it carries some risks like any medical intervention. Major complications requiring death, stroke, or emergency surgery are very rare in electrophysiology study, occurring in about one in a thousand cases. The frequency of milder complications is around one percent. The rate of these risks may vary depending on the patient’s general health condition, heart functions, and type of arrhythmia.
Frequently Asked Questions About EP
Is EP study an Angiography?
No, while the EP study procedure is performed in an angiography laboratory, it is not an angiography procedure. Angiography is performed to examine the vessels feeding the heart, while EP study is a procedure aimed at diagnosing and treating arrhythmias.
Is EP study Procedure Painful?
Since local anesthesia is used during EP study, there is generally no pain. However, some patients may feel slight discomfort during the procedure.
When Will EP study Procedure Results Be Available?
Results are usually evaluated immediately after the procedure is completed. The detailed report is prepared within a few days.
Can EP study Be Repeated?
Yes, the EP study procedure can be repeated when necessary. In some cases, multiple EP study procedures may be performed.
Can EP study Be Performed on Patients with Pacemakers or ICDs?
Yes, EP study can be performed on patients who have a pacemaker or ICD (implantable cardioverter-defibrillator). However, device settings should be checked before the procedure.
Reference: Electrophysiological Study