During electrophysiology testing, catheters (thin, flexible wires) with electrodes at the tips are threaded through the patient’s blood vessels at several places within the heart. These wires have electrodes on them which sense the electrical activity inside the heart- much like an ECG does from the chest surface. During the test, the electrophysiologist may use the electrodes to stimulate the heart to beat at rates that may trigger, or halt, an irregular heartbeat . By pacing at different sites inside the cardiac chambers, the normal conduction system of the heart and the heart’s normal pacemaker functions can be studied. With additional pacing maneuvers attempts can be made to induce an abnormal heart rhythm (arrhythmia). For example, if the physician determines that catheter radiofrequency ablation (a minimally-invasive procedure that uses catheters to reach the heart and destroy abnormal heart tissue) is the appropriate treatment, the procedure can be performed during EP testing.

Catheter ablation can then potentially cure this rhythm, or if the EPS is looking to see if someone is at risk of dying suddenly, a positive test can lead to a defibrillator implant.

ElectroPhysiology Study

Preparing for the EP study
  • We will tell you ahead of time whether to stop taking any of your medications. Do not modify your medications without prior approval.
  • You will have to sign an Informed Consent form, which details any risks or problems that may occur.
  • You do not to eat or drink after midnight the night before the procedure
  • The area where the catheter will be inserted will be thoroughly cleaned and shaved. This is usually in the groin, but may be in the neck. You will receive a local anesthetic in that area.
  • You will be given a mild sedative for some procedures and general anesthesia for certain ablations.