An Intracardiac Electrophysiology Study (EPS) is a test used to examine the electrical system of the heart. The test or study involves placing special wires called electrodes within the heart to determine which areas of heart tissue give rise to the abnormal electrical impulses that cause heart rhythm disorders (arrhythmias). EPS may be recommended for patients with symptoms that suggest they may have a heart rhythm disorder, or for people who may be at risk for Sudden Cardiac Death.