Click above to view an animation of an EP Study

An electrophysiology study, or EP study, is performed to evaluate the electrical activity of the heart. This is typically performed by an electrophysiologist, which is a cardiologist that specializes in the electrical system of the heart.

The purpose of the electrical system of the heart is to coordinate the pumping of the four chambers of the heart and to control the heart rate so that the heart speeds up and slows down as the demands of the body change. The SA node starts the electrical signal. The electrical signal then travels through the atria causing them to contract. Then it passes through the AV node the bundle of His, and bundle branches and then out to the muscle fibers of the ventricles. As the impulse spreads, the muscles contract and the ventricles pump. The EP study identifies the path of the heart's electrical conduction.

To perform an electrophysiology study, three to five electrically sensitive catheters are placed inside the heart to record electrical activity. These recordings locate abnormal tissue that causes irregularities in the heartbeat (arrhythmias).

The electrodes detect the heart's electrical activity and map out any irregular heartbeats. This helps the electrophysiologist see the type of arrhythmia you have and where the problem starts in your heart. Abnormal electrical activity can occur anywhere along this heart's conduction system. Normally, the heart's electrical signals move through the the two chambers on the top of the heart (the atria), to the atrioventricular (AV) node, and then to the lower chambers of the heart (the ventricles).

Your cardiologist may order this test if you have signs of an abnormal heart rhythm (arrhythmia). Information from this study helps your cardiologist/electrophysiologist to determine the severity of the arrhythmia as well as appropriate treatment.

An EPS may be done to:

• Pinpoint the location of a known arrhythmia and determine the best therapy
• Determine the severity of the arrhythmia and whether you are at risk for future heart events, especially sudden cardiac death
• See if medicine is controlling an abnormally heart rhythm
• Evaluate the need for a permanent pacemaker or an implantable defibrillator (ICD)