An electrophysiology (EP) study is an accurate method for assessing the heart's electrical function. It allows doctors to locate abnormal sites inside the heart that may be causing serious arrhythmias (abnormal heart rhythms).

 

During an EP study, doctors insert special electrode catheters (long, flexible wires) into veins and guide them into the heart. Once inside, the catheters can sense electrical impulses in various areas of the heart; they can also be used to stimulate different parts of the heart.

 

The EP study provides more accurate and detailed information about the heart's electrical function than other diagnostic tests. It helps doctors diagnose the problem accurately and enables them to choose the most effective treatment.

 

EP studies are most useful in people who have had life-threatening arrhythmias, and in people with persistent symptoms in whom suspected arrhythmias could not be diagnosed with other tests.

 

The EP study is performed in a specially equipped room called an EP lab.  The patient will be transported to the EP lab on a movable bed and then transferred to an x-ray table. The table has a large camera about it and television screens close by. The equipment in the EP lab also includes heart monitors and various instruments and devices.

 

The EP lab team generally includes the electrophysiologist, an assistant, nurses, and technicians.

 

After being positioned on the x-ray table, the patient is connected to a variety of monitors and covered with sterile sheets. The staff will be wearing gowns and gloves.

 

The area(s) where the catheters are inserted (groin, arm, shoulder or neck) is cleansed thoroughly. A local anesthetic is injected into the skin with a tiny needle to numb the area.

 

A small incision is made in the skin and a needle is used to puncture the blood vessel (usually a vein) into which the catheters will be inserted.

 

The special electrode catheters used for the EP study are long and flexible wires that can conduct electrical impulses to and from the heart. One or more catheters are inserted into the body and advanced toward the heart, while the staff follows their progress on a television screen. The catheters are then positioned inside the heart.

 

The EP study is performed by doing two basic things: 1) recording electric signals (electrode catheters sense electrical activity in various areas of the heart and measure how fast electrical impulses travel) and 2) pacing the heart (electrode catheters can also be used to deliver tiny electrical impulses to pace the heart; doctors try to induce certain abnormal heart rhythms so that they can be observed under controlled conditions).

 

If an arrhythmia is induced, medications may be given through the IV line to test their effect on the heart rhythm. If arrhythmias cannot be induced after a medication has been given, that medication may prevent similar arrhythmias in the future.

 

The EP study helps define the exact location of the heart's abnormal electrical activity (this part of the study is called mapping). The location and type of arrhythmia will help determine the best treatment option.

 

Patients are awake during the procedure, although medication may be given to help patients relax. The staff will be monitoring progress constantly.

 

The EP study usually is not painful, although patients may feel some pressure at the insertion site(s) during the insertion of the electrode catheters. There also may be some discomfort from lying still for a long time. Patients will not feel the catheters moving through the blood vessels and into the heart.

 

During the procedure, doctors may stimulate the heart with tiny electrical impulses that may induce the arrhythmia that has caused symptoms.

 

An EP study is an invasive procedure that requires the insertion of catheters into the body. It therefore involves some risk. The risk is small, however, and the EP study is considered relatively safe.

 

Some patients may develop bleeding at the insertion site. Blood collects under the skin, resulting in local swelling and/or a bruise in the groin or arm.

 

Less frequently, EP studies may be associated with more serious complications. These include damage to the heart or blood vessels, formation of blood clots, and infection. Deaths are very rare.

 

Although most patients who undergo EP studies do not experience complications, you should be aware of the risk. To learn about your particular risk, you should discuss the matter with your doctor.

 

After the procedure is completed and the catheters are removed, the doctor or nurse will apply firm pressure to the insertion site for about 10 – 20 minutes. This is done to prevent bleeding. If the insertion site was in the arm, the doctor may close the incision with a few stitches.

 

You'll be transported to your room or the recovery area. Whether you are allowed to eat or drink soon after the study depends on your condition.

 

Back in your room, you'll lie flat in bed for 2 to 4 hours (occasionally longer), to allow a small seal to form over the puncture in the blood vessel. During that time, do not bend or lift the leg where the catheters were inserted. If you feel sudden pain at the site or if you notice bleeding, notify the nurse immediately.

 

The doctor who performed the study may be able to discuss with you some of the test findings soon after the procedure. A complete, detailed analysis of all of the measurements will take more time.

 

Depending upon the results of the study, you may be sent home after several hours of observation or the next day. When it's time to go home, have a friend or family member drive you.

 

At home, after your EP study:

 

·                    Limit your activity during the first 24 hours after you return home. You can move about, but do not strain or lift heavy objects.

·                    If you notice new blood on the dressing, place your fingers over the site and press firmly for about 20 minutes. If bleeding continues, call your doctor or go to the nearest emergency room while continuing to apply pressure.

·                    Leave the dressing on the insertion site(s) until the day after the procedure. The nurse will tell you how to take it off and when it's okay to take a shower.

·                    A bruise or a small lump under the skin at the insertion site is common. It will generally disappear within 3 to 4 weeks.

·                    Call your doctor or nurse if the insertion site becomes painful, warm to the touch, the bruising or swelling increases, or you develop a fever over 100 ^oF.

·                    Call your doctor if you have recurrence of your rapid heart rhythm, or if you experience dizziness, chest pain, or shortness of breath.

·                    Be sure to check with your doctor or nurse about medications – which ones to continue and which ones to stop.