Electrophysiology (ep) study

An electrophysiology study is used to check your heart's electrical system. For example, it may be done to:

• Identify heart rhythm problems.
• Check your heart before you have an ICD (implantable cardioverter-defibrillator) implanted.
• Treat certain problems with catheter ablation.

Before the test

• Be sure to empty your bladder completely just before the test.
• You will be taken to a special room, sometimes called a "cath lab" or "EP lab." You will lie on a flat table under a large X-ray machine.
• Several small electrodes will be placed on the skin of your chest, legs, and arms. These are connected to an EKG machine that keeps track of the electrical activity of your heart during the test.
• A device called a pulse oximeter may be clipped to your finger. It measures oxygen levels in your blood and monitors your pulse.
• An intravenous (I.V.) needle will be inserted into a vein in one of your arms to give you fluids or medicine during the test.
• You will be kept comfortable and safe by your anesthesia provider. You may be asleep during the test. Or you may get medicine that relaxes you or puts you in a light sleep. The areas where the catheters will go into blood vessels will be numb. If you are awake during the test, the medicine may make you so sleepy that you may not remember much afterward.
• The areas where the doctor plans to insert a catheter will be shaved and cleaned. This is usually in your groin, neck, or arm. Sterile towels will be draped over your body, except for the areas over the insertion sites.

During the test

• A doctor called a cardiac electrophysiologist inserts the catheter through your skin and into the blood vessel.
• The doctor slowly pushes the catheter through the blood vessel toward your heart. Usually several catheters are used. The doctor moves the catheters into various places in the heart. An X-ray screen shows the doctor where to move the catheters.
• The catheters have small electrical conductors, called electrodes, on their ends. The doctor can use the electrodes to do what is called "pacing." This means sending electrical currents through the catheters to try to re-create your heart rhythm problem. This can tell the doctor what kind of problem you have and the best way to treat it. The doctor may also use pacing to see how well medicines work to control your problem.
• The electrodes also send information to a computer. The computer uses the information to draw pictures of your heart and its rhythm problems. This is called "mapping," because the pictures serve as maps that show the doctor exactly where the problem areas are.
• The doctor might give you a medicine through the IV that starts the abnormal heart rhythm. You might feel your heart beat fast and strong. You might also feel jittery or very nervous.
• Your doctor may let you watch the video monitor so you can see the pictures of your heart.

After the test

• After the procedure, pressure may be applied to the areas where a catheter was put into a blood vessel. This will help prevent bleeding and allow your blood vessels to heal. A small device may also be used to close the blood vessel. You may have a bandage or a compression device on each catheter site.
• If the catheter was put in your groin, you will need to lie still and keep your leg straight for up to a few hours. The nurse may put a weighted bag on your leg to keep it still.
• If the catheter was put in your neck or arm, you may be able to sit up right away. If it was put in your arm, you will need to keep your arm still for at least 1 hour.
• You will be taken to an observation room where nurses and others can watch your heart rate, blood pressure, and temperature for a while and check for signs of bleeding.
• If you have an EP study only, you may go home the same day. If you also have ablation or other treatment, you may stay overnight in the hospital.

Procedures can be stressful for both your child and you. This information will help you understand what you can expect. And it will help you safely prepare for your child's procedure.

Preparing for the procedure

• Talk to your child about the procedure. Tell your child that the procedure will help the heart work as it should. Hospitals know how to take care of children. The staff will do all they can to make it easier for your child.
• Ask if a special tour of the surgery area and hospital is available. This may make your child feel less nervous about what happens.
• Understand exactly what procedure is planned, along with the risks, benefits, and other options.
• Tell the doctor ALL the medicines, vitamins, supplements, and herbal remedies your child takes. Some may increase the risk of problems during the procedure. Your doctor will tell you if your child should stop taking any of them before the procedure and how soon to do it.
• Plan for your child's recovery time. Your child may need more of your time right after the procedure, both for care and for comfort.

An electrophysiology study will show whether you have an abnormal heartbeat that needs treatment. (Sometimes the treatment is done during the test.)