An Electrophysiology Study (or EP Study) is an electrical study of the heart from the inside. It aids in the diagnosis of problems involving the electrical conduction system of the heart, and for the evaluation of abnormal heart rhythms. It involves inserting catheters through the veins in the groin that track up into the heart under X-ray guidance where they take sensitive electrical recordings from the heart’s conduction system. Your doctor may order this test if you have signs of an abnormal heart rhythm. The results from this study helps your doctor learn how severe the arrhythmia is and may establish a need for other treatment including medications, Pacemaker, ICD, and ablation procedures.