What is a pacemaker?
A pacemaker is a small device that uses electrical impulses to control the speed and rhythm of your child’s heartbeat.
How does the normal heart work?
The heart is a pump that moves blood through your body. The rate and rhythm of the heartbeat are normally controlled by the
heart's own natural electrical system. The upper portion of the heart has its own pacemaker, called the sinus node. Electrical
impulses start in the sinus node and travel down through the atria (upper chambers), causing them to contract. The impulses
then reach the place where the atria join the ventricles (lower chambers).
This place is called the AV node. The AV node sends the impulses through the muscles of the ventricles, causing them to contract.
When the ventricles contract, they pump the blood out of the heart to the rest of the body.
For more information, please see "How the Body Works: Electrocardiogram (ECG)."
Why does my child's heart need a pacemaker to work normally?
There are several reasons why a child might need a pacemaker. The two main reasons are heart block and sick sinus syndrome.
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Heart block: With heart block, the electrical impulses do not pass normally between the upper and lower chambers because of
a blockage at the AV node. This blockage can exist before birth (
congenital heart block) or can result from
surgery to repair
a
cardiac defect.
Acquired heart block can result from heart infections (such as endocarditis or
myocarditis) or even from
certain drugs.
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Sick sinus syndrome: In sick sinus syndrome, the sinus node does not work properly. The result is that the heartbeats are
too slow or too fast.
How does the pacemaker work?
The pacemaker has two parts: the pacemaker itself and the lead (wire).
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The pacemaker: This is a small metal container that holds the battery and electrical circuits. It is very small, weighing
less than 2 ounces. It is placed under the skin and muscle, either near the shoulder or near the stomach area. The pacemaker
watches for the natural electrical activity of the heart, and sends electrical impulses to make the heart beat only when necessary.
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Leads: The electrical impulse from the pacemaker travels through insulated wires with metal tips called leads that are in
contact with your child's heart. Depending on the type of pacemaker, the leads may be attached to the upper chamber of the
heart, the lower chamber, or both.
What kinds of pacemakers are available?
Pacemakers come in many different makes and models. Your child’s doctor will decide which kind of pacemaker your child should
have. For more information about pacemakers, you can talk to your doctor or the pacemaker clinic staff.
Transvenous vs. epicardial pacemaker systems
In children, pacemakers can be placed in one of two ways:
| Pacemaker Types |
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| A transvenous pacemaker lead is passed through a vein to the correct location inside the heart. An epicardial pacemaker lead
is stitched to the outside of the heart muscle.
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Single vs. dual chamber pacemakers
A single chamber pacemaker system has 1 pacing lead that is placed either in the top (atrium) or the bottom (ventricle) chamber
of the heart. A dual chamber pacemaker has 2 pacing leads, with 1 lead each in the top and bottom chambers of the heart.
Rate-responsive pacemakers
Pacemakers can adjust the pacing rate according to the level of the patient’s activity. For example, most pacemakers have
built-in sensors that can detect body motion such as walking or running and increase the pacing rate in proportion to the
patient’s activity.
Your child should avoid strong electric and magnetic fields
Strong magnetic fields will interfere with the pacemaker's ability to sense the heart's activity. When this happens, the pacemaker
will respond by sending out its pacing impulses at a fixed rate. It will not turn itself off. Your child needs to take precautions
with the following:
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If your child visits the Hydro exhibit at the Ontario Science Centre, he should stay behind the rope because the strong magnet
can interfere with the pacemaker.
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If your child has Industrial Arts classes at school or is interested in mechanical hobbies, he should not work with arc welders
or alternators.
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Any procedure involving electrical equipment that is used in a doctor's office or an operating room may interfere with the
pacemaker's function or change the pacemaker's settings. An example is electrocautery, which uses electricity to burn (cauterize)
tissue.
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Magnetic resonance imaging (
MRI), a procedure done in health care facilities, should not be performed on anyone with a pacemaker.
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Items containing magnets, such as magnetic jewelry, toys with large magnets, and some headphones should be kept at least 6
inches away from the pacemaker.
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In general, any electronics, particularly those with antennas that transmit electrical signals, should be kept at least 6
inches away from the pacemaker. An example is a cellphone.
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Your child should walk past anti-theft detectors normally and should not linger between the gates. The pacemaker may activate
the alarm but should not be affected by it.
A microwave oven will not interfere with the function of your child's pacemaker.
Activity
Most children with a pacemaker can play and work normally. But there are a few precautions. Your child should avoid sport
activities that may cause repetitive, direct impact to the pacemaker, such as karate and kickboxing. Repeated blows could
weaken or damage the leads. The pacemaker clinic staff will discuss these precautions with you and your child.
Use this space to write down any questions and notes:
Your child's cardiologist will discuss with you any other activity restrictions that are related to your child's underlying
heart condition.
How often must the pacemaker be changed?
The pacemaker battery is reliable and the battery level goes down very gradually. The pacemaker battery information is obtained
at each routine pacemaker clinic visit. The pacemaker is replaced when its battery reaches the replacement level. At this
level, there is still a 2- to 3-month window where the pacemaker continues to work properly. This allows time for the doctor
to book the surgery electively.
In general, a pacemaker may last between 5 to 8 years depending on how often it is being used and how much energy is used
for pacing. Surgery may be done sooner if there are problems with the pacing lead wire(s) or the pacemaker system. Your child
will be admitted to the hospital for about a 2-day stay to have the surgery to replace the pacemaker.
What happens in the pacemaker clinic?
Clinic staff will check your child's pacemaker by using a small computer. The pacemaker's settings, such as heart rate, can
be changed using this computer. Your child will not feel any discomfort or pain during this procedure.
Chest X-rays may be taken if the cardiologist thinks there may be a problem with a lead. X-rays will also be taken about once
a year to check the position and length of the pacemaker's leads.
In addition, a Holter monitor will be used once a year. This allows the cardiologist to check the pacemaker's functions.
For more information, please read "Holter Monitors."
Follow-up appointments
Attend all appointments at the pacemaker clinic (usually once every 6 months) and at the office of your child's cardiologist.
Regular medical follow-up is very important.
When the battery is starting to get low, some follow-up may be done over the telephone using a monitoring device called a
telephone transmitter. This method is helpful, but it does not replace regular clinic visits.
Who to call if you have questions
If you are concerned about your child, please seek medical attention. Call your family doctor or paediatrician, or call 911
as needed. You may also call the pacemaker clinic staff if you have any specific questions about the pacemaker.
Key points
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A pacemaker is a small device that uses electrical impulses to control the speed and rhythm of your child’s heartbeat.
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Your child should avoid strong electric and magnetic fields, as these can interfere with pacemaker function.
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Your child should not play sports where there is a risk of repetitive blows to the pacemaker area.
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Regular follow-up appointments with both the cardiologist and the pacemaker clinic are important.
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If you are concerned about your child, please seek medical attention. If you have questions about the pacemaker, please call
the pacemaker clinic staff.
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| Last Reviewed | Reviewed by |
| August 27, 2009 |
Carrie Morgan, RN, MN Christine Chiu-Man, MSc
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