Electrophysiology (EP) Study

About This Procedure

Based on information gathered during an electrophysiology study, Massachusetts General Hospital physicians can diagnose your particular arrhythmia and select the appropriate treatment.

This test is performed in a specially equipped room, usually referred to as the EP Lab. During the study, doctors place special electrode catheters (long, flexible wires) into the veins and guide them into the heart. These catheters are used to measure the electrical conduction system of the heart. They are also used to stimulate different regions of the heart (known as pacing) to attempt to induce an arrhythmia. The procedure is very safe and effective in diagnosing cardiac arrhythmias. A team of highly trained physicians and nurses care for you during the procedure.

After being positioned on an X-ray table, you will be connected to a variety of monitors that measure heart rate, blood pressure and oxygen level. A medication is given through an IV to relax you and to make you feel sleepy (this is called conscious sedation). A local anesthetic is used to numb the area where the physician will place the catheters. After the area is numb (the leg), catheters will be inserted into the vein(s) and positioned in the heart using X-ray imaging.

Once the catheters are positioned, you may feel a sensation in the chest as the physicians are pacing your heart. This is often felt as a fluttering sensation. Most patients sleep through the procedure. After the electrophysiology study, which generally takes one to two hours, the catheters are removed, and pressure is held at the site where the catheters entered the body.

From the EP Lab, you are brought back to your room and asked to remain on bed rest for four to six hours while the vein(s) heals. Your cardiologist will discuss the results of the study with you and recommend an appropriate course of action.