In order for your heart to do its work (to pump oxygen rich blood throughout your body) it needs electrical energy to generate a heartbeat.

This impulse begins in the Sinus (SA) Node, which is the heart's natural pacemaker. The SA Node is located in the heart's upper right chamber. From there the impulse travels down a specialized system of conductive tissues, causing the heart muscle to contract in an orderly sequence. The two upper chambers of the heart squeeze a little earlier than the lower two chambers.

The SA node sends impulses that cause your heart to beat normally -- 60 to 100 beats per minute. Depending on your activity, your heart beats lower (at rest) or faster (with activity).

There are conditions where the electrical impulse becomes blocked during its journey, causing an abnormally slow heartbeat (Bradycardia). In other conditions, an abnormal or "irritable pacemaker" outside the Sinus Node may cause an unusually fast heartbeat called Tachycardia. If the Tachycardia comes from the upper chambers of the heart it is referred to as SVT or Supraventricular Tachycardia. If it comes from the lower chambers, it is referred to as VT or Ventricular Tachycardia.

Once a heart rhythm disturbance has been suspected, your doctor will recommend an EP Study. Your EP Study will be performed in a laboratory with special diagnostic equipment and heart monitoring devises. An Electrophysiologist, a cardiologist who specializes in the electrical conduction of the heart, will conduct the study.

For EP Study patient information, click here.