The Heart & Vascualr Center

CARDIAC ELECTROPHYSIOLOGY TESTING:

WHAT IT IS AND HOW IT BENEFITS US

By: Walter R. Hepp, M.D.

An electrophysiology study (EP study) evaluates the electrical conduction system of the heart looking for explanations for such symptoms as passing out or evaluating certain arrhythmias (irregular heart beats). Patients may also be referred for an EP study after surviving a cardiac arrest or other findings that may place them in an extraordinarily high risk category.

The electrophysiology lab is similar to the laboratory used for heart catheterizations or
angiograms. During an angiogram, a physician injects contrast dye into the coronary arteries and is able to see blockages in the heart. A local anesthetic is given to "numb" the skin, and the area where the catheter is inserted is also carefully sterilized.

The catheter is called a cardiac sheath. Through this sheath, temporary pacemaker catheters the size of a piece of spaghetti are placed in strategic positions of the heart. These catheters record electrical activity inside the heart and allow the physician to alter the rhythm pattern. By altering the rhythm pattern, the physician can learn a lot about what is causing the rhythm disturbance.

Throughout the procedure the physician is continually evaluating every aspect of the patient's
conduction system. The physician will be monitoring for any induction of fast heartbeats, also known as tachycardias. If these tachycardias appear, it helps the physician determine the best treatment to control the problem. During the test, patients may experience no symptoms whatsoever, or they may feel lightheaded. The physician will take immediate action if the
situation warrants.

Complications from the electrophysiology studies are minimal. There are three basic benefits to patients undergoing electrophysiology testing. In those patients who have a question as to why they suffered a specific symptom, electrophysiology testing often identifies those causes most readily. In patients who have survived a cardiac arrest, electrophysiology tests may identify a potentially life-threatening arrhythmia which would explain the specific event.

Once a cause is identified, it can then be best managed either medically or surgically. Lastly for those patients with rapid heartbeats, electrophysiology testing after identifying the cause of the arrhythmia can sometimes be used to cure the patient of this arrhythmia through a specific procedure called radio frequency ablation.