Electrophysiology study (EPS). This test is used to assess serious arrhythmias. During an EPS, a thin, flexible wire is passed through a vein in your groin (upper thigh) or arm to your heart. The wire records your heart's electrical signals.
Your doctor can use the wire to electrically stimulate your heart and trigger an arrhythmia. This allows your doctor to see whether an antiarrhythmia medicine can stop the problem.