Electrophysiology Study (EP)
Electrical signals in your heart make the heart muscles
contract, which pumps blood to your body. If the
electrical signals are not flowing well through the
heart, this can create serious problems.
An electrophysiology study is a test where electrode
wires are passed through a blood vessel and into your
heart. This electrode can record or create electrical
activity. This can help find any problems with the flow
of electricity in your heart.
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Reasons for Procedure
An electrophysiology study is performed to:
Find the cause of abnormally slow heart
rhythms ( bradycardias )
Find the source of abnormally fast heart
rhythms ( tachycardias )
Provoke and diagnose heart arrhythmias
(irregular heart beats) that occur
Reveal suspected arrhythmias
Evaluate a person’s risk for sudden
Assess symptoms of unknown cause,
Need for a pacemaker
Need for an implantable
Need for cryoablation
(destruction of some
heart cells by freezing)
If you are planning to have an electrophysiology study,
your doctor will review a list of possible
complications, which may include:
Blot clot formation
Injuries to blood vessels or the heart
Abnormal heart rhythm
A person’s risk level is very individual. It may relate
to the specific arrhythmia suspected and any underlying
What to Expect
Prior to Procedure
Follow your doctor’s instructions.
Do not drink or eat anything after midnight the
night before the procedure.
You doctor may order:
Electrocardiogram —recording of
the heart's electrical activity
Talk to your doctor about your medicines. You
may be asked to stop taking some medicines up to
one week before the procedure, like:
Aspirin or other
Blood thinners, such as
clopidogrel (Plavix) or warfarin
A local anesthetic will be given by needle. It
will numb the area where the catheter will be
inserted. You will also receive a mild sedative
through an IV in your arm. This will help you to
relax during the test.
Description of the Procedure
You will be asked to lie down on an
examination table. Electrodes will be
placed on your chest. The electrodes
will help to monitor your heart rhythm
during the test. An area on your thigh,
neck, or just below your collarbone will
be cleaned. A thin electrical wire will
be inserted into a blood vessel in that
The electrode will be passed through the blood
vessel and into your heart. Your doctor will be
able to see the progress of the catheter with
the help of x-rays on a screen. The tip of the
electrode can send electrical signals to your
heart. The signals will make the heart beat at
different speeds. Your heart rhythm will be
recorded to look for abnormalities. The tip of
the electrode can also record electrical
activity at specific spots in your heart muscle.
How Long Will It Take?
The length of the test will vary based on what
your doctor is investigating. The test may take
2-4 hours or more to complete.
Will It Hurt?
You may feel some mild discomfort with the
initial injection. As the doctors induce an
arrhythmia, you may feel palpitations, shortness
of breath, chest discomfort, or you may even
lose consciousness. The medical team can usually
control arrhythmias with medicines, but they may
need to administer a shock to stop some rhythms.
If they need to do this, you will receive more
sedation so that you do not feel pain.
Average Hospital Stay
If your doctor does not need to do additional
procedures, you may be able to go home after
about six hours. However, you may need to remain
in the hospital for up to 24 hours if additional
procedures are done during the study.
At the Care Center
EKG and blood studies may be
You will likely need to lie
still and flat on your back for
a period of time. A pressure
dressing may be placed over the
area where the catheter was
inserted to help prevent
bleeding. It is important to
follow the nurses' directions.
You will need to rest in bed
until the sedative has worn off.
Your heart rate and blood
pressure will be monitored. You
will also be checked for
swelling or infections. If
necessary, you may be given pain
medicine. After resting for at
least 4-6 hours, your doctor
will let you know if you can go
home that day or if you need to
be admitted for more treatment
or observation. If you are
discharged on the same day as
the test, you should have
someone drive you home.
The results of the study may be
available before you leave the hospital
or in the next few days. Your doctor
will notify you if you need any
When you return home, do the following
to help ensure a smooth recovery:
Do not lift heavy
objects or engage in
strenuous exercise or
sexual activity for at
least 24 hours.
Change the dressing
around the insertion
area as instructed.
Take medicines as
Ice may help decrease
discomfort at the
insertion site. You may
apply the ice for 15-20
minutes each hour, for
the first few days.
Be sure to follow your
doctor's instructions .
Call Your Doctor
After arriving home, contact your doctor if any of the
Signs of infection, including fever and
Redness, swelling, increasing pain,
excessive bleeding, or any discharge
from the insertion site
Cough, shortness of breath, or chest
Your leg feels cold, turns white or
blue, or becomes numb or tingly
Discomfort in the jaw, chest, neck,
arms, or upper back
Dizziness or weakness
In case of an emergency, call for medical help right
American Heart Association http://www.americanheart.org/
Texas Heart Institute http://www.texasheartinstitute.org/
Heart and Stroke Foundation of Canada http://ww2.heartandstroke.ca/splash/
University of Ottawa Heart Institute http://www.ottawaheart.ca/
HeartCenter Online website. Available at:
http://www.heartcenteronline.com . Accessed November 22, 2004.
North American Society of Pacing and Electrophysiology website.
. Accessed November 22, 2004.
Texas Heart Institute website. Available at:
http://texasheartinstitute.org/ . Accessed November 22, 2004.
Reviewer: David N. Smith, MD
Review Date: 12/2011
Update Date: 12/30/2011