A Patient’s Guide to
MRI Conditional
Pacemakers
Your Pacemaker
A pacemaker monitors the heart’s rate (how
fast it beats) and rhythm (the pattern in which
it beats), and provides electrical stimulation
when the heart does not beat or beats too slowly
(bradycardia).
What a Pacemaker Does
A pacemaker is typically used for cardiac
rhythm disorders involving a too-slow heart rate
(bradycardia) or because electrical impulses get
delayed on their way through the heart.
The pacemaker “listens” to the heart. When the
heart’s own electrical system sends a signal and
the heart beats, the pacemaker waits and does
nothing. When the heart’s system misses a signal,
the pacemaker sends a signal to replace it.
Example of one type
of bradycardia
(third-degree AV block).
Example of a normal
sinus rhythm.
Why is MRI compatibility important?
MRI is fast becoming a preferred diagnostic
tool used by physicians in the treatment of
cancer, stroke, heart-related conditions, and
musculoskeletal disorders or injury and is
particulary used in patients over the age of 65.
Because of its high-resolution image quality
and low-radiation risk, MRI is often selected
over other diagnostic techniques. Each year
up to 8 million MRI scans are performed in
Europe. That number is increasing significantly,
however, as the use of MRI continues to grow.
Historically, pacemaker patients have not been
able to benefit from MRI technology due to the
risk of interference with the pacemaker.
The extremely strong magnetic fields used in
MRI procedures could affect the pacemaker’s
normal functions; therefore, patients with
traditional pacemakers should not have MRIs.
Experts estimate that as many as 75% of pacemaker patients will have medical
need for MRI.1
1 Kalin R and Stanton MS. Current clinical issues for MRI scanning of pacemaker and defibrillator
patients. PACE 2005;28:326–8.
What do I need to know about having a
pacemaker and getting an MRI scan?
Some newer pacemakers are MRI (or MR)
conditional. This means that they are designed
to allow you to safely undergo an MRI scan
under certain conditions, due to safeguards
in the system’s design that protect it from the
risks a non-MRI conditional system might face.
How do I know if I can safely undergo
an MRI with my pacemaker?
As a patient with an MRI conditional system,
you should have received a special patient card
that identifies you as having an MRI conditional
system. It is important for you to carry this
card with you at all times. Sometimes MRI
procedures are planned, and other times they
are needed under unexpected circumstances.
You will need to let the healthcare professionals
caring for you, as well as the MRI technologist
or radiologist, know that you have an MRI
conditional system.
With an MRI conditional system, you can be
comfortable knowing that the device has been
designed for safety under set conditions in the
MRI environment.
What can I expect before an MRI scan?
Your pacemaker needs to be put into special MRI
settings for you to safely undergo an MRI scan.
There are two ways your doctor might do this.
The first way is for your doctor to program your
pacemaker to the special MRI settings ahead of
time and store those settings in the pacemaker.
This programming happens during a follow-up
appointment.
Then, when you need an MRI scan, the MRI
settings are enabled by a clinician, who places
a small hand-held device over your pacemaker.
The hand-held device uses radio waves to
communicate with your pacemaker and enable
the pre-programmed MRI settings. Activating
the MRI settings is painless and takes
only moments.
The second method involves programming your
device to MRI settings when it is determined you
need an MRI scan. With this method, your doctor
uses the programmer to temporarily set your
device to MRI settings before your MRI scan.
What can I expect after an MRI scan?
After the MRI scan, your device needs to be
returned to its regular settings. In other words,
your MRI settings need to be disabled. This can
be accomplished in the same two ways in which
your MRI settings were enabled.
With the first method, the hand-held device is
placed back over your device to disable MRI
settings and enable your pacemaker to go back
to its permanent settings. With the second
method, the programmer is used to program
your device back to its regular settings after
the scan.
With either method, your device is placed back
to its regular settings.
Your MRI conditional pacemaker is designed
to give your heart the support it needs, in
addition to ensuring you can receive the best
in diagnostic imaging in the future should that
need arise. Your doctor is the best source of
information about your total overall health. It is
important to discuss any questions or concerns
you might have with him or her.
My additional notes and questions:
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My follow-up questions:
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Atrial Fibrillation
Cardiac Rhythm Management
CARDIOVASCULAR
Neuromodulation
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+46 8 474 40 00
+46 8 760 95 42 Fax
(GMCRM857EN)
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Note: This pamphlet is not intended to take the place of the manufacturer’s
patient manual provided with each device.
Prior to using these devices, please review the User’s Manual for a complete listing
of indications, contraindications, warnings, precautions, potential adverse events
and directions for use. Unless otherwise noted, ® or TM indicates a registered or
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©2011 St. Jude Medical, Inc. All rights reserved. Item No.GMCRM857EN.