Test Overview
An electrophysiology
study, or EP study, is a test to see if there is a problem with your heartbeat (heart rhythm)
and to find out how to fix it.
In this test, the doctor inserts
one or more flexible tubes, called catheters, into a vein, typically
in the groin or neck. Then he or she threads these catheters into the heart. At the tip of
these catheters are electrodes, which are small pieces of metal that conduct
electricity. The electrodes collect information about your heart's electrical
activity. Your doctor can tell what kind of heart rhythm problems you have and
where those problems are.
Sometimes the problem can be fixed at the same time. A procedure called
catheter ablation uses the catheters to destroy
(ablate) small areas of your heart that are causing the problem.
Heart Problems: Should I Have Catheter Ablation?
Why It Is Done
An electrophysiology study is used
to:
- Identify heart rhythm problems.
- See
how well heart rhythm medicines work for you.
- Check your heart
before you have a
pacemaker or an
ICD (implantable cardioverter-defibrillator)
implanted.
- Treat certain problems with
catheter ablation.
How To Prepare
Tell your doctor if
you:
- Are allergic to any medicines, including iodine, or to latex.
- Have any bleeding problems or take blood-thinning medicine
(anticoagulants), including any nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin or ibuprofen.
- Are or might be pregnant.
- Have
diabetes.
- Have ever had clots in your legs, groin, or pelvis.
- Have a filter in a large vein to prevent clots from traveling to the heart.
Talk to your doctor about any concerns you have about the
need for the test, its risks, how it will be done, or what the results will
show. To help you understand the importance of this test, fill out the
medical test information form(What is a PDF document?).
Tell your doctors all the medicines, vitamins, supplements, and herbal remedies you take. Some of these can increase the risk of bleeding or interact with anesthesia. Your doctor will tell you which medicines to take or stop before your procedure.
If you take blood-thinning medicine, be sure to talk to your doctor. He or she will tell you if you should stop taking this medicine before your procedure. Make sure that you understand exactly what your doctor wants you to do.
Arrange for someone to take you home
after the test. You may not have to stay in the hospital overnight.
Do not eat or drink (except for a small amount of water) for a few
hours before the test. If you are taking any medicines, ask your doctor if you
should take them on the day of the test.
Take off any nail polish. That will make it
easier for doctors and nurses to check the circulation in your fingers and
toes.
Be sure to empty your bladder completely just before the
test.
How It Is Done
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 attached to your legs and arms with a special paste or gel.
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 (IV) needle will be inserted into a vein in one of your
arms to give you fluids or medicine during the test. You will receive a
medicine to help you relax (sedative) through the IV line. You may
be awake during the test. But even if you are awake, the sedative may make you
so sleepy that you may not remember much afterward.
- The area where
the doctor plans to insert a catheter will be shaved and cleaned. Sterile
towels will be draped over your body, except for the area over the
insertion site.
During the test
- A
local anesthetic is injected into your skin at the
insertion site. This is usually in your groin or neck. When the area is numb, a doctor called a
cardiac electrophysiologist inserts the catheter through your skin and into the vein.
- The doctor slowly pushes the catheter through
the vein 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.
- A nurse or other assistant will help
you stay comfortable and resist the urge to move around. Be careful not to
touch the sheets or reach for your groin area, because you could contaminate
the sterile areas and increase the risk of infection.
- Your doctor
may let you watch the video monitor so you can see the pictures of your heart.
- The test takes 1 to 3
hours.
Catheter ablation usually takes 2 to 6 hours. In rare
cases, it can take longer.
After the test
- It's important to prevent bleeding after the
catheter is pulled out. For example, if the catheter was in your groin, firm
pressure will be applied there for about 10 minutes to stop the bleeding. Then
a pressure dressing will be placed over the area.
- 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.
They also watch the pulse, color, and temperature of the arm or leg in which
the catheter was placed.
- If the catheter was in your groin, you may
have to lie in bed with your leg extended for as long as 4 to 12 hours. This
allows your blood vessels to heal.
- If you have an EP study only, you will likely go home the same day. If you also have
ablation or other treatment, you may stay overnight in
the hospital. How long you stay in the hospital depends on the type of ablation
you have. Most people can go back to work and their normal routine in 1 or 2
days.
How It Feels
You
will feel a sharp sting when the local anesthetic is injected to numb your skin
at the catheter insertion site.
When the catheter is inserted, you
may feel a brief, sharp pain. The movement of the catheter through your blood
vessel may cause a feeling of pressure, but it is not usually considered
painful. You may feel your heart skip when the catheter touches the walls of
your heart. This is normal.
The temperature in the catheterization
lab is kept cool so that the equipment does not overheat. For many people, the
hardest part of the test is having to lie still for an hour or longer on the
hard table. You may feel some stiffness or cramping.
Don't be afraid to speak up if you're
worried about anything during the test. The doctors, nurses, and technicians
want to know exactly how you're feeling.
It's
especially important to tell the doctor if you have any of these symptoms
during or after the test:
- Chest pain
- Extreme shortness of
breath
- Dizziness
- Trouble speaking or
swallowing
- Paralysis in any part of your
body
You may have some soreness and bruising at the insertion
site. This should disappear in 2 weeks. It is normal for the site to feel
tender for about a week. But call your doctor if:
- Your arm or leg becomes pale, cold, painful, or
numb.
- You have redness, swelling, or discharge from the catheter
insertion site.
- You have a fever.
Risks
An electrophysiology study is considered safe. The risks of this test are small.
The more common complications are not serious. They include bleeding or bruising where the catheters were put in.
Serious complications are rare. But they include extra bleeding after the test, puncture of the heart, and damage to the electrical system
of the heart that requires a pacemaker.
Very serious complications, such as heart attack or stroke, are very rare.
This test is not usually done during pregnancy, because
it involves X-rays. Radiation could damage the developing
fetus.
Anytime you are exposed to radiation, including the low
levels of X-ray used for this test, there is a chance of damage to cells or
tissue. But the risk of this damage is usually very low compared to the
possible benefits of the test.
Results
An electrophysiology study will show whether you have an
abnormal heartbeat that needs treatment. (Sometimes the treatment is done
during the test.)
What Affects the Test
Reasons you may not be able to have the test or
why the results may not be helpful include:
- Extreme anxiety that causes high blood pressure and irregular
heartbeats.
- Kidney or liver failure.
- Not being able to
follow directions during the procedure.
- Not being able to lie flat.
- Ongoing bleeding problems or infection.
What To Think About
An electrophysiology study can be scary. You may find it helpful to
talk to your doctor ahead of time about your fears. If you are awake during the
test, you can ask questions and let your doctor and others know how you're
feeling.
Other Places To Get Help
Organizations
| American Heart Association (AHA) |
| 7272 Greenville Avenue |
| Dallas, TX 75231 |
| Phone: |
1-800-AHA-USA1 (1-800-242-8721) |
| Web Address: |
www.heart.org |
| |
|
Visit the American Heart Association (AHA) website for information on
physical activity, diet, and various heart-related conditions. You can search for information on heart disease and stroke, share information with friends and family, and use tools to help you make heart-healthy goals and plans. Contact the AHA to find your
nearest local or state AHA group. The AHA provides brochures and information
about support groups and community programs, including Mended Hearts, a
nationwide organization whose members visit people with heart problems and
provide information and support.
|
|
| Heart Rhythm Society |
| 1400 K Street NW |
| Suite 500 |
| Washington, DC 20005 |
| Phone: |
(202) 464-3400 |
| Fax: |
(202) 464-3401 |
| Web Address: |
www.hrsonline.org |
| |
|
The Heart Rhythm Society provides information for
patients and the public about heart rhythm problems. The website includes a
section that focuses on patient information. This information includes causes,
prevention, tests, treatment, and patient stories about heart rhythm problems.
You can use the Find a Specialist section of the website to search for a heart
rhythm specialist practicing in your area.
|
|
| National Heart, Lung, and Blood Institute
(NHLBI) |
| P.O. Box 30105 |
| Bethesda, MD 20824-0105 |
| Phone: |
(301) 592-8573 |
| Fax: |
(240) 629-3246 |
| TDD: |
(240) 629-3255 |
| Email: |
nhlbiinfo@nhlbi.nih.gov |
| Web Address: |
www.nhlbi.nih.gov |
| |
|
The U.S. National Heart, Lung, and Blood Institute
(NHLBI) information center offers information and publications about preventing
and treating:
- Diseases affecting the heart and circulation, such as heart
attacks, high cholesterol, high blood pressure, peripheral artery disease, and
heart problems present at birth (congenital heart diseases).
- Diseases that affect the lungs, such as asthma, chronic
obstructive pulmonary disease (COPD), emphysema, sleep apnea, and
pneumonia.
- Diseases that affect the blood, such as anemia,
hemochromatosis, hemophilia, thalassemia, and von Willebrand disease.
|
|
References
Other Works Consulted
- Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis:
Saunders.
- Fischbach FT, Dunning MB III, eds. (2009).
Manual of Laboratory and Diagnostic Tests, 8th ed.
Philadelphia: Lippincott Williams and Wilkins.
- Miller JM, Zipes DP (2012). Diagnosis of cardiac arrhythmias. In RO Bonow et al., eds., Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine, 9th ed., vol. 1, pp. 687–709. Philadelphia: Saunders.
- Tedrow UB, et al. (2011). Electrophysiology and catheter-ablative techniques. In V Fuster et al., eds., Hurst's The Heart, 13th ed., vol. 1, pp. 1058–1070. New York: McGraw-Hill.
Credits
| By |
Healthwise Staff |
| Primary Medical Reviewer |
Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology |
| Specialist Medical Reviewer |
John M. Miller, MD, FACC - Cardiology, Electrophysiology |
| Last Revised |
September 14, 2012 |
