An electrophysiology study, or EP study, is a test to see if there is a problem with your heartbeat (heart rhythm) and to find out how to fix it.
In this test, the doctor inserts one or more flexible tubes, called catheters, into a vein, typically in the groin or neck. Then he or she threads these catheters into the heart. At the tip of these catheters are electrodes, which are small pieces of metal that conduct electricity. The electrodes collect information about your heart’s electrical activity. Your doctor can tell what kind of heart rhythm problems you have and where those problems are.
Sometimes the problem can be fixed at the same time. A procedure called catheter ablation uses the catheters to destroy (ablate) small areas of your heart that are causing the problem.