Electrophysiological Studies

Overview

What is an Electrophysiology Study?

An electrophysiology study (EPS) is an invasive procedure that tests the heart's electrical system. The procedure is performed in an area similar to a cardiac catheterization lab. In fact, in some ways, the procedure itself is similar to a cardiac catheterization.

A small, plastic catheter (tube) is inserted through the groin (or arm, in some cases) and is threaded up into the heart, using a special type of x-ray, called fluoroscopy, to guide the catheter. Once in the heart, electrical signals are sent through the catheter to the heart tissue to evaluate the SA node and the rest of the conduction pathways. A dysrhythmia may be induced (caused) by the electrical signal, in which case medication may be given to treat the dysrhythmia and try to induce it again to evaluate the effectiveness of the medication. Mapping, done to locate the spot where a dysrhythmia starts from, may be done. If a location is found that is the cause of the dysrhythmia, an ablation (removal of the spot by freezing or radiofrequency) can be done, which should stop the dysrhythmia.

The results of the study will help the physician determine further therapeutic measures, such as the insertion of a pacemaker or defibrillator, adding or changing medications, additional ablation procedures, or other treatments.

Reasons for the Procedure

As previously mentioned, some reasons your physician may request EPS may include, but are not limited to, the following:

• to evaluate a symptomatic patient for dysrhythmia when other noninvasive tests have been inconclusive
  
  
• to determine the effectiveness of medication(s) given to treat a dysrhythmia
  
  
• to assess the effectiveness of a pacemaker or implanted defibrillator device
  
  
• to locate the source of a dysrhythmia

Risks of the Procedure

Possible risks of EPS include, but are not limited to, the following:

• inducement of more severe dysrhythmia
  
  
• perforation of the heart muscle
  
  
• heart attack from inducement of a very fast rhythm, or from a clot being dislodged by the catheter
  
  
• stroke (brain attack) from a clot being dislodged by the catheter
  
  
• bleeding from the catheter insertion site
  
  
• damage to the vessel at the catheter insertion site
  
  
• infection of the catheter site

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