His Bundle Electrography is a test that measures electrical activity in a part of the heart known as the bundle of His. The bundle of His is a group of fibers that carry electrical impulses through the center of the heart to ensure that the heart beats correctly. His bundle electrography is part of an electrophysiology (EP) study. An intravenous catheter (IV line) is started in your arm to allow for the administration of medication during the procedure. Electrocardiogram (ECG) leads are placed on your extremities. A catheter is inserted through a small incision in a vein in your arm, neck or groin that is carefully threaded into the heart using an X-ray image technique called fluoroscopy to guide the insertion. ECG monitors your heart for arrhythmias (abnormal rhythms of the heart) during catheter placement. The catheter, which is equipped with an electrode, then measures the electrical activity of the bundle of His.