Electrophysiology Study (EPS)

Front view of female outline showing heart, major arteries and veins. Catheter inserted in femoral vein going to right heart.

An EP study is an invasive but nonsurgical procedure done by a cardiac electrophysiologist. This is a doctor who specializes in heart rhythm evaluation and treatment. The EP study can be used to evaluate your heart's electrical system, screen for arrhythmias, guide treatment for arrhythmias, and evaluate the risk of arrhythmia formation in certain heart conditions.

Before the procedure

  • Tell your doctor which medicines you take. Ask if you should stop taking them before the procedure, especially blood thinners or medicines that affect heart rate or rhythm.

  • Have any routine tests that your doctor recommends, such as blood tests.

  • Don’t eat or drink anything after midnight the night before the procedure, or 8 hours before the procedure.

During the procedure

  • The study takes about 1 to 2 hours.

  • You will be given medicine through an intravenous line (IV) to help you relax.

  • Your skin is numbed with a local anesthetic. This can be on the right leg, the left leg, or both.

  • The doctor then insert one or multiple IV lines into the femoral vein.

  • Using pulsed X-ray called fluorscopy, your doctor will then insert wires into the heart and place them in specific locations to record the heart's electrical activity.

  • The electrical activity of the heart will be measured carefully. Pacing and program stimulation of the heart will then be done. This involves adding additional heartbeats in an orderly fashion to test the heart's electrical system. It also tests whether an abnormal heart rhythm can be induced.

  • Medicines that stimulate the heart can be used to help induce an abnormal heart rhythm.

  • Once your doctor gets the needed information, the wires will be removed from the body.  

  • The IV lines will be removed from the groin.

  • Pressure is applied to the insertion site to prevent any bleeding. 

After the procedure

  • You will be asked not to move your leg that had the catheter for 2 to 6 hours after the procedure. You will need to lie still in bed.

  • A nurse will check the insertion site and monitor your vital signs.

  • After the study, you may stay overnight, or you may go home the same day. This will depend on the results of the study as well as the indication for the procedure.

When to call your doctor

Contact your doctor if: 

  • The insertion site has pain, increased swelling, redness, bleeding, or drainage

  • You have shortness of breath or chest pain

  • You have severe pain, coldness, numbness, or a bluish color in the leg or arm that held the catheter

  • You have a fever over 100.4°F (38°C)