An electrophysiology (EP) study is a test that may be done to find what is causing an abnormal heart rhythm.

Some abnormal rhythms are caused by problems in the heart’s conduction system. The conduction system is made up of special cells linked together in pathways. These pathways carry the electrical impulse that causes the heart to beat and pump.

An EP study checks the heart’s electrical function in several ways. It measures the speed of an electrical impulse traveling through the conduction system. It locates pathways that are in the wrong place. EPS also helps to identify many types of abnormal heart rhythms by trying to reproduce them. The test will help your healthcare provider understand if medicine, a pacemaker, or an implantable defibrillator will help your symptoms or reduce your risk of sudden cardiac death.