What is an Electrophysiology Study?
An Electrophysiology (EP) test or study looks at the conduction or electrical
system of your heart by recording electrical activity from within the heart
chambers. Thin wires are advanced into the heart through a small tube similar to
cardiac catheterization to see if the irregular heartbeat can be reproduced. An
EP study allows the doctor (Electrophysiologist) to study heart rhythm
disturbances (arrhythmias) in a controlled setting.
What does the test show?
The EP study results can help your doctor determine if you have a heart
rhythm disturbance or diagnose your abnormal heart rhythm. It can show how well
medications work. This information helps determine the best treatment. The test
also can be used to see how well your defibrillator (ICD) operates during your
abnormal heart rhythm.
In order for your heart to beat, it needs an electrical impulse to generate a
heart beat (More information about heart anatomy). Your heart’s natural
pacemaker (sinoatrial node) normally makes your heart beat 60-100 times per
minute. This is called sinus rhythm. There are conditions when the electrical
impulse becomes blocked in its route down the conduction system that cause an
abnormal slowing of your rhythm. This is called Bradycardia and refers to a
heart rate of less than 60 beats per minute.
In other conditions, an abnormal or “irritable pacemaker” outside the
sinoatria node may cause a very fast heart rhythm to occur. This is called
Tachycardia and refers to a heart rate of greater than 100 beats per minute. If
the tachycardia comes from the upper chambers of the heart it is called
Supraventricular Tachycardia (SVT). If it comes from the lower chambers it is
Ventricular Tachycardia (VT).
Either too slow or too fast a heartbeat may cause the following symptoms:
- Dizziness or lightheadedness
- Palpitations (a fluttering or pounding in the chest)
- Fainting spells
- Shortness of breath
How do I prepare for the test?
- Do not eat or drink anything after midnight the night before your
procedure because you need to be fasting for at least 8 hours.
- Medications should be taken as scheduled with a sip of water unless
special instructions are given to stop your meds. Your doctor may advise you
to stop taking certain medications before your EP study to obtain more
accurate test results.
- Be sure to mention to the doctor or nurse if you have any allergies
- Make arrangements with a family member or friend to drive you home after
the procedure - you probably will not be permitted to drive. Family members
and friends can wait in an assigned area.
- Pack a small bag in case your doctor decides to keep you overnight in the
hospital. You may want to include a robe, slippers, toiletries, and a book /
word games (something to pass the time).
- Leave money, jewelry, and valuables at home unless a family member or
friend can hold them for you during the procedure.
- Bring a list of all medications you are currently taking. Your doctor may
want to continue them while you recover from your procedure.
- Tell your doctor if you take aspirin or a blood thinner because they may
need to be stopped several days before the procedure.
- Several routine tests are done before the EP study:
- EKG (electrocardiogram)
- Blood tests
- Medical history and exam
- Chest x-ray
Who gets arrhythmias?
Arrhythmias are usually a byproduct of damage to the heart from disease or
age. People with otherwise healthy hearts can develop an arrhythmia, but it is
rare. Many things can damage your heart’s electrical system and lead to an
electrical problem: diseases of the heart valves, enlargement of the heart,
coronary artery disease, high blood pressure, lung disease, congenital heart
problems (existing at birth) and scarring from a heart attack.
What happens during an Electrophysiology Study?
The Electrophysiology Study may be done as an inpatient
or in many cases, as an outpatient. If you are an outpatient, arrive 1-1/2 hours
to 2 hours before your procedure pending on blood work needed. After you go
through admitting, you will go to the pre op area (Ambulatory Surgery) – located
on the ground floor Outpatient Care - unless other arrangements have been made. You will change
into a hospital gown. An intravenous line (IV) will be started in a
vein in your arm and you will be given consent to sign for the procedure.
You will be transported to the EP laboratory located on the ground floor
operative/cardiology unit. You will arrive to the laboratory approximately 30 minutes before your procedure begins, so
our highly trained staff can prepare you and get you relaxed for the procedure. Sometimes
a scheduled procedure time must be changed because of an emergency case. Please keep
in mind that we try our best to remain on schedule however, sometimes
some procedures do take longer than we may expect.
Pending on the outcome of your procedure if you are
scheduled to return home that day you will be taken to post op (Ambulatory Surgery) –
located on the ground floor Outpatient Care for recovery until you are discharged. If you are
scheduled to stay overnight our specialized trained cardiology nurses for Cardiac Lab and
Electrophysiology Procedures will care for you on our new Cardiovascular Care Unit on
the second floor of the main hospital building.
Once in the EP lab, you will be transferred to a table. Electrodes (sticky
patches) will be placed on your chest, back, arms, and legs. You may need to be
shaved so the electrodes will stick. You will also be hooked up to other
monitoring devices such as a blood pressure cuff and oxygen monitor. You will
need to lie still and relax during the test because movement or muscle tensing
can interfere with the electrical signals.
The area where the catheters are to be placed (in the groin, arms or neck)
will be cleansed with an antiseptic solution. Sterile towels and sheets will be
placed over you, leaving exposed only the area where the catheters will be
inserted. The doctor will inject a numbing medicine in the areas where the
catheters will be inserted. You will feel some stinging at that time. Once the
medication takes effect, you should not feel any discomfort.
Once the areas are numb, one to four special insulated wires (called
catheters) are inserted into different parts of your heart using a special x-ray
machine. This machine allows the doctor to watch the catheters as they move into
the correct places. Part of the x-ray machine will be placed directly over your
entire body. You will receive only intermittent low dose x-rays.
After the catheters are in position, the doctor evaluates your heart rhythm
disturbance by giving your heart small electrical impulses by an artificial
pacemaker through one of the catheters. This will make your heart beat at
different rates. You may feel your heart beating quickly, or experience
fluttering or palpitations. If you feel chest pain or discomfort, let the doctor
You may be asked questions during the test such as:
“Do you feel faint?”
“Do you feel your heart pounding?”
“Is this feeling similar to one you
have had before?”
“Do you feel dizzy or lightheaded?”
“Are you short of
“Do you have chest pain or pressure?”
Some patients pass out when the doctor is inducing a rapid heart rhythm. If
you do pass out, it will be for a very short period of time. A small electrical
shock may be required to bring back your normal heart rhythm. Most patients
report that they do not experience any pain. Some patients do not even realize
they have passed out.
If you do have an irregular rhythm, the doctor may prescribe a cardiac
medication. This drug will be given through your IV. You blood pressure, heart
rate, oxygen levels will be monitored during this time. Once an adequate dose of
the drug is given, the doctor will check to see how effective it is in
controlling your irregular rhythm.
When the EP study is completed, the doctor will remove the catheters. To
prevent bleeding, pressure will be applied to the catheter insertion site until
the bleeding stops. A small sterile dressing will be applied which will be
removed the next day. No stitches will be required. You will return to a
recovery area on a stretcher.
The catheter insertion areas require time to heal, so you will need to follow
- Bed rest for 3-6 hours.
- Do not cross your legs and keep the legs straight if the catheters were
inserted in the groin. To sit up or bend your knees may cause bleeding at the
- Report any symptoms to your nurse such as chest pain, swelling in the
insertion sites, warmth, anything unusual.
The nurse will make sure you are given something to eat or drink, make sure
you are comfortable, answer any questions or concerns, check your blood pressure
and heart rhythm (EKG), help you with urination, etc.
What is Catheter Ablation?
The EP study and ablation procedure are very similar. In fact, your doctor
may decide to do both procedures, one after the other, while you are in the EP
lab. This possibility will be discussed with you prior to the study.
Catheter ablation is a non-surgical technique that is used to destroy heart
muscle cells responsible for an arrhythmia. The procedure can be quite lengthy.
An ablation procedure can last for 2-4 hours. This procedure is the preferred
treatment for many types of arrhythmias.
During catheter ablation, a doctor guides a catheter through a vein in your
leg to your heart. The catheter is positioned in the area of your heart
responsible for the arrhythmia. Electrodes at the tip of the catheter emit radio
frequency (heat) energy through it that destroys the heart muscle cells
responsible for the arrhythmia.
Drug therapy for arrythmias
Medication: If the doctor diagnoses you with a heart rhythm
disturbance (arrhythmia) after the study, he/she will prescribe a medication
(antiarrhythmic) to control your arrhythmia. Antiarrhythmic medications can help
alleviate symptoms and prolong life. Some sample medications include:
Quinidine – used to treat patients with Supraventricular (SVT) and
Ventricular Arrhythmias (VT), such as Atrial Fibrillation (afib) or flutter,
Paroxysmal Supraventricular Tachycardia (PSVT), and Premature Ventricular
Contractions (PVCs). The drug comes in several forms, including Quinidine
Sulfate (Ci-Quin) and Quinidine Gluconate (Duraquin).
Propranolol (Inderal) – decreases heart rate and contractility.
Reduces the incidence of sudden cardiac death after a heart attack.
Sotalol (Betapace) – decreases heart rate, slows AV conduction,
decreases cardiac output, and lowers blood pressure.
Amiodarone – used to treat SVT, PSVT, VT, Wolff-Parkinson-White
*Medications may not be the answer for treating your arrhythmia. If this is
the case, your doctor will discuss other ways of treating your problem, such as
a pacemaker or defibrillator (AICD).
Where is the test performed?
St. Mary has two state-of-the art Electrophysiology Labs,
than 1,200 procedures annually.
How long does this test take?
An EP study usually takes 1-4 hours.