An electrophysiological study is used to diagnose and treat cardiac rhythm disturbances.
Using special pacing wires, the doctor can identify your rhythm disturbance and choose the best method of treatment.
On this page: Arrhythmia · Before the EPS · During the EPS · After the EPS
Arrhythmia: abnormal heart beats
There are conditions where the normal electrical conduction of your heart becomes disrupted. This causes abnormal heart rhythms, or arrhythmia.
There can be many different reasons for this, so ask your doctor to explain your particular condition to you.
Before the EPS
The doctor will discuss the test with you and your family, and answer any questions, as well as discussing potential risks and complications.
You will be asked to sign a consent form. Women should tell the doctor if there is any chance they might be pregnant, as x-rays are used to guide the pacing catheters.
The next steps are:
- medical history and physical examination
- electrocardiogram, chest x-ray and blood tests
- your right groin area is shaved
- an intravenous cannula (a small plastic tube) is inserted into a vein in your arm. This may be used to give medication during your test.
- fasting for four hours before your test.
During the EPS
The procedure usually takes 1 to 1½ hours. It is performed in a special laboratory under local anaesthetic, so you will be awake and able to communicate with the doctor and staff. You may be given medication through the cannula to help you relax.
You will be attached to an ECG monitor by the cardiac technician or nurse, who both assist the cardiologist throughout the procedure.
The doctor will be dressed in theatre garments, and will clean the groin area with antiseptic, and cover you with green sterile drapes. The doctor will then inject a local anaesthetic into your groin. This may cause a brief stinging sensation as the area goes numb, but once the medication has taken effect you should not feel any discomfort.
The catheters or pacing wires are introduced through the groin into the leg vein and guided. With the use of an x-ray camera above the bed the wires are placed into the correct position in your heart. You will have no sensation of this, as there are no nerve endings in the blood vessels.
Between one and four pacing electrodes are placed in different positions in the heart. The doctor will give small electrical impulses through the electrodes, which will cause your heart to beat at different rates. You may feel your heart beat very quickly, or experience ‘skipped beats'. This is part of the test and you should not be alarmed. However, let the staff know if you feel any discomfort or chest pain.
It is possible during the test for the doctor to initiate a rapid heart rhythm. It is very important that the doctor knows how you feel at this time. You may be asked questions such as:
- Do you feel dizzy or lightheaded?
- Do you feel your heart pounding?
- Is this similar to the feeling you had before?
During the test the doctor may administer medication to control your heart rhythm. The doctor will monitor how effective this medication is for you. This will be given through the cannula.
In some cases a rapid heart rhythm may cause you to pass out for an extremely short period of time. A small electric shock may be required to restore your normal rhythm. Although it may be frightening to think of this possibility, most patients do not report experiencing any pain. Some people do not even recall passing out.
When the EPS is completed, the doctor will remove the catheters and apply pressure to the insertion site for 5–10 minutes to prevent bleeding. A small sterile dressing will be applied, which may be removed after 24–48 hours. No stitches are required. The results of your EPS will be explained to you by your doctor.
After the EPS
You will be returned to your ward where you will need to rest in bed for about two hours. A nurse will monitor your pulse and blood pressure, and observe the groin for signs of bleeding. You will be able to eat and drink.
If your doctor prescribes medication for your heart rhythm disturbance, it is important for him to make sure it is working correctly. You may need to have a follow-up study after a period of time on medication; this test is similar but usually a much shorter procedure.
Compiled by Ann Kirkness and Rachel Peake, Cardiovascular Education Centre
