What is a Electrophysiology Study?

An electrophysiologic study (EPS) is a detailed analysis of the electrical conduction system of the heart.  This type of test is used to determine in the heart beats at normal rythem or at a irregular rythem.  An irregular heart beat is called an arrhythmia.  Electrophysiologic studies are done to:

• Determine if a patient requires a pacemaker.
• Determine why a person is fainting if other tests have been negative.
• Determine if a person is prone to troublesome, disabling, or life-threatening fast heart rhythms and guide the appropriate treatment.
• Assess the results of prior therapy for fast heart rhythms.

How the test is performed:
The test is performed by placing thin plastic tubes into a vein where the leg connects to the stomach. A local anesthetic is given as well as a mild sedative. The procedure is not painful and the patient is not put to sleep.

After being placed into the vein, these long thin tubes, called catheters, are then passed into the heart under fluoroscopic guidance. These catheters measure the electrical signals generated by the heart. This gives a much more detailed analysis of these signals than does a simple electrocardiogram ECG.

The catheters are also used to rapidly pace the heart, i.e. make the heart beat fast. The electrical conduction system of the heart is also measured during this rapid pacing and the heart is observed during this rapid pacing to see if any abnormal heart rhythms develop.
 
Sometimes, an intravenous medicine is infused and the study repeated to determine the effect of that medicine.

The studies usually take 2 hours but can occasionally last longer.

How to prepare for the test:
The test requires that the patient eat nothing after midnight the night before. Some medications may need to be withheld before the test. These include some medicines that regulate the heart beat, the powerful blood thinner coumadin as well as some diabetic medicines. This is normal performed as an outpatient procedure.

How the test will feel:
You may feel some discomfort at the site where the IV is placed. Local anesthesia will be used to numb the site, so the only sensation should be one of pressure at the site.  You can resume normal activities the following day unless advised otherwise by their physician.