Download electrophysiology (ep) study - Sir Charles Gairdner Hospital

“ELECTROPHYSIOLOGY
(EP) STUDY”
Patient Information Booklet
Sir Charles Gairdner Hospital
Department Of Cardiovascular Medicine
Sir Charles Gairdner Hospital
Cardiovascular Medicine
Level 4 G Block
Verdun Street
NEDLANDS WA 6009
Ph (08) 9346 2677
Fax (08) 9346 2483
e-mail [email protected]
Revised June 2012
Coordinator Cardiac Rehabilitation
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Index
BACKGROUND ............................................................................. 4
WHAT IS AN ELECTROPHYSIOLOGY (EP) STUDY? ................ 5
PREPARATION FOR THE EP STUDY......................................... 6
IN THE LAB ................................................................................... 7
AFTER THE PROCEDURE .......................................................... 9
RESULTS AND TREATMENT .................................................... 10
CATHETER ABLATION TREATMENT ....................................... 11
WHAT ARE THE RISKS? ........................................................... 12
AT HOME .................................................................................... 13
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BACKGROUND
The heart consists of two upper chambers (atria) and two lower chambers
(ventricles) and is a very strong and efficient muscular pump. Its job is to keep
blood, carrying oxygen and nutrients, supplied to all parts of the body.
To ensure that the heart contracts and pumps in an orderly sequence there is a
small area of specialised cells, known as the sino-atrial node (S-A) node, situated
in the top right chamber. This node sends out messages (electrical impulses) to
the heart muscle, through special nerve pathways and the atrio-ventricular (A-V)
node, causing it to contract and pump blood. This happens each time the heart
beats.
A normal heartbeat is frequent and regular; this is called sinus rhythm.
Depending on your fitness and age, the average resting heart rate in adults is
usually 60 to 90 beats per minute. Heart rates outside this range are not
necessarily abnormal. Your heart rate will change with activity and can be
affected by certain medications.
In some people the heart may beat abnormally slowly (bradycardia) or
abnormally fast (tachycardia). The electrical impulse may be interrupted or
delayed and cause this abnormal heart beat. What is felt when the heartbeat is
abnormal varies depending on the heart rate, type of rhythm and how the heart’s
pumping action is affected.
Symptoms of an abnormal heart rhythm may include:
♥ feeling tired
♥ light-headedness
♥ faintness or even blackout
♥ palpitations
♥ pain or pressure in the chest
♥ shortness of breath.
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WHAT IS AN ELECTROPHYSIOLOGY (EP) STUDY?
An Electrophysiology (EP) Study is a procedure in which the electrical activity of
the heart is examined carefully under controlled circumstances. It can provide
information that is unobtainable by other tests. This is done by inserting one or
more long thin wires (an electrode catheter) into the heart and stimulating the
heart muscle with very small electrical impulses.
An EP study may be ordered to:
♥ examine the hearts response to these electrical impulses
♥ establish the mechanism (or locate the focus) of any abnormal rhythms and
determine whether they are the cause of your symptoms
♥ help in the selection of the most appropriate therapy, such as medications,
catheter ablation, pacemaker insertion, defibrillator implantation or surgery.
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PREPARATION FOR THE EP STUDY
If you are unwell prior to coming to hospital, that is if you have a cold or infection,
it may be necessary to postpone the procedure. Please notify your doctor if this is
the case.
Bring your current medications with you to hospital.
Before the EP study you may require or be required to:
♥ Chest X-ray
♥ Electrocardiogram
♥ Bloods taken
♥ Understand of the procedure and after care
♥ Sign a consent form
♥ Hair shave around groin and/or chest area
♥ An IV (drip) insertion
♥ Notify doctor if you have any allergies
♥ Fast at least 6 hours prior to the EP study
♥ Take your usual medications except:
Diabetic tablets
Diuretic (fluid) tablets
Anticoagulants (e.g. Warfarin)
If you take medications to control your abnormal heart rhythm you may or
may not be given these, depending on the type of study
You will be given specific instructions about your medications.
♥ Change into a hospital gown and disposable underwear
♥ Jewellery to be removed and sent home. (There is no need to remove glasses
or dentures)
♥ Empty your bladder just before leaving the ward
♥ You will be taken to the Catheter Lab on your bed
♥ Take your own radio or stereo with head phones to listen to during the
procedure if you wish
Note: Usually your test will take place as scheduled but occasionally emergency
patients may need to be attended to first or the previous procedure can be longer
or shorter than anticipated.
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IN THE LAB
The EP studies will be performed in the Catheter Lab located on level 4 of G
block, Department of Cardiovascular Medicine.
Inside the lab you will have to lie flat on an X-ray table. If you have back
problems or find it difficult to lie flat for long periods discuss this with your doctor
prior to the procedure so that medication to make you more comfortable can be
given. You will be connected to an ECG machine and a large cool pad adhered
to your chest and back. Your heart rhythm and blood pressure will be monitored
throughout the procedure.
To prevent infection, your groin and or neck (depending on which vein the doctor
wishes to access) will be cleansed with a cool antiseptic (usually iodine) solution.
Most of your body will be covered with sterile sheets. It is important that you do
not touch the top of these sheets or move around once you are covered. You will
be asked to keep your arms by your side. If your nose itches or you need to
cough or move for any reason, tell one on the nursing staff. They will do their
best to keep you comfortable.
As the doctor injects some local anaesthetic into your groin or neck you will
experience a slight stinging sensation, closely followed by numbness in that area.
After the anaesthetic has taken effect you may feel a sensation of pressure but
there should be no pain or discomfort. Additional injections can be given as
necessary.
When the area is numb a special needle will be inserted into the vein. One or
more hollow sheaths are inserted into the vein and through these sheaths
catheters (flexible electrodes to record electrical activity) are advanced to various
areas of the heart. X-ray pictures will be taken to assist with the positioning of
the tube into the chambers of the heart.
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IN THE LAB CONTINUED
A low humming sound can be heard when the X-ray machine is in use and at the
same time the lights will be dimmed so that the pictures can be easily seen. The
X-ray table and camera will also move about during this time to get pictures at
various angles.
+ Although you will be only receiving a low dose of X-ray it is very
important to inform your doctor before the procedure if there is a
possibility that you may be pregnant.
In some cases the doctor will need to put a catheter into an artery via your groin
in addition to one in your vein in order to access the left side of the heart.
Once the catheter(s) are positioned, small electrical impulses will be delivered to
various parts of the heart to try and map the electrical activity. You may feel
some fluttering in the chest while this is being done. This is normal and no cause
for alarm. You may also have some symptoms similar to those caused by your
abnormal heart rhythm. If this makes you feel uncomfortable let the doctor know,
as these rhythms can be stopped at any stage. In some instances a fast heart
rhythm may be induced that requires defibrillation, that is, an electric shock
delivered via the large adhesive pads on your chest. You won’t feel the shock, as
it will only be delivered if you loose consciousness.
The doctor may also wish to stimulate your heart with medications through your
drip. This can make you feel nervous, sweaty and your heart pound for few
seconds only. Try to relax and concentrate on breathing normally.
The length of time it takes to perform this procedures varies from patient to
patient. In some instances it can take up to four hours. The length of time taken is
not a reflection of the severity of your problem.
When the procedure is completed you will be transferred to either G42 (if a
period of monitoring is required) or G41.
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AFTER THE PROCEDURE
The catheters used during the procedure will be removed in the cath lab or on
G42. If the doctor needs to put a catheter into an artery, the removal of this
catheter is more involved. A clamping device is placed over the puncture site to
apply pressure to that area for approximately 30 minutes. You will be required to
lie flat and still for 4 hours once the clamp has been removed.
Notify the nurse if you feel any of the following symptoms:
♥
♥
♥
♥
♥
♥
♥
Bleeding from you puncture site
Swelling, numbness or pain of the affected leg
Palpitations
Dizziness or light headedness
Shortness of breath
Chest pain or discomfort
Feeling unwell in any way.
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RESULTS AND TREATMENT
Once the test results have been studied your Cardiologist will discuss them with
you and the kind of treatment that is required.
Medication treatment may be advised and this usually requires extra days in
hospital until the medication (drug) reaches an effective level within your system.
In some cases a Pacemaker may be required if the heart beat is too slow for any
reason.
Ablation therapy is another alternative for some abnormal heart rhythms. This is
usually done at the time of the EP Study. Your cardiologist will discuss this with
you before the procedure if he/she feels that it might be appropriate treatment.
See next page for more information on catheter ablation.
Another alternative for the treatment of some arrhythmias is the implantation of
an internal cardiac defibrillator. This will be discussed with you, by your
Cardiologist if he or she feels that it is appropriate.
Depending on the problem identified during the EP study, you may need to
undergo additional testing at a later date. This will allow your doctors to evaluate
the effectiveness of treatment given for your abnormal heart rhythm. The second
EP study is usually much shorter in duration than the initial study.
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CATHETER ABLATION TREATMENT
Some abnormal rhythms can be treated by ablation therapy, particularly those
involving the atria (the upper heart chambers). This involves applying a high
frequency current though a catheter to the area of tissue in the heart located in
the EP study. This current, delivered in pulses lasting 30 to 60 seconds at a time,
destroys the electrical pathway or group of cells responsible for the abnormal
heart rhythm.
By destroying the abnormal pathway it is anticipated that the heart’s normal
pathway will then be allowed to work. In some cases damage will result to the
normal pathways, slowing the heart rate down. You may then require a
pacemaker to be inserted. In some cases your cardiologist will know that a
pacemaker will be required and will inform you if this is likely before the
procedure.
Usually a catheter ablation requires you to be admitted to hospital just for the
day. In some cases you may be required to stay over night.
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WHAT ARE THE RISKS?
As with all medical procedures, EP testing and Catheter Ablation carry some
risks about which you should be informed.
These risks include:
 Infection or bleeding at the sites where the catheters are inserted
 Blood clots in the leg (usually where the catheters were inserted),
approximately 1 in 500 procedures
 Damage (perforation) to the blood vessels, heart chambers or heart valves - 1
in 500 procedures
 Collapsed lung (which usually only occurs if it is necessary to place a catheter
from the neck) - approximately 1 in 1000 procedures
 Stroke - approximately 1 in 1000 procedures
 Death is very rare, approximately 1 in 5000 procedure
 Damage to the heart’s normal electrical pathway requiring insertion of a
pacemaker (usually only occurs if catheter ablation is performed) approximately 1 in 200 ablation procedures.
If you have any question about these risks please discuss them further with your
doctor.
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AT HOME
Once discharged you will be able to resume all normal activities (the issue of
driving may need to be discussed with your cardiologist). It is normal for the
puncture sites to be tender and slightly bruised. However if you notice:
♥ the bruised area continues to enlarge significantly,
♥ the wound becomes reddened or hot,
♥ there is any fluid or pus coming from the sites,
♥ you have pain or discomfort that doesn’t go away, or
♥ any sudden increase in leg swelling,
it is important that you seek medical attention immediately.
Your medications may be altered after the procedure. It is important to remember
that you can not stop, alter or omit your medications without consulting your
doctor.
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