High Quality Content by WIKIPEDIA articles! An electrophysiology study (EP test or EP study) is a minimally invasive procedure which tests the electrical conduction system of the heart to assess the electrical activity and conduction pathways of the heart. The study is indicated to investigate the cause, location of origin, and best treatment for various abnormal heart rhythms. This type of study is performed by a specialist (an electrophysiologist) and is performed using a single or multiple catheters situated within the heart through a vein or artery.