Medtronic DDMD3D1 Product Information

Medical Procedure and EMI Warnings and Precautions

for implantable cardiac defibrillators

Manual for Health Care Professionals

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1 Warnings, precautions, and guidance for medical procedures and electromagnetic interference (EMI)

1.1 Introduction

This manual is intended for physicians and other health care professionals who treat patients who have an
implantable cardiac defibrillator (ICD) or a cardiac resynchronization therapy defibrillator (CRT-D). To view this
manual online, to download it, or to see the latest list of device models to which this manual pertains, refer to the
Medtronic Manual Library at www.medtronic.com/manuals.

Section 1.2 of this document is useful to health care professionals who perform medical procedures on patients
with Medtronic cardiac pacing systems and who consult with the patients’ cardiologists. This section provides
warnings, precautions, and guidance related to medical therapies and diagnostic procedures that may cause
serious injury to a patient, interfere with the system, or permanently damage the system. Some common medical
procedures that pose no risk are also listed.

Section 1.3 of this document provides precautions and other information related to electromagnetic interference
(EMI) that is helpful to patients in their daily living. Health care professionals can review the information with their
patients and use it as a reference for post-implant appointments.

For guidance on medical procedures or potential EMI scenarios that are not addressed in this manual, contact the
following resources:

●

Customers in the United States can contact Medtronic Technical Services at [phone]. You may also
submit questions to [e-mail] or your Medtronic representative.

●

Customers outside of the United States can contact a Medtronic representative.

1.2 Warnings, precautions, and guidance for clinicians performing medical procedures on cardiac device patients

Ablation (RF ablation or microwave ablation) – Ablation is a surgical technique in which radio frequency (RF)

or microwave energy is used to destroy cells by creating heat. Ablation used in cardiac device patients may result
in, but is not limited to, induced ventricular tachyarrhythmias, oversensing, unintended tissue damage, device
damage, or device malfunction. Pulse-modulated ablation systems may pose higher risk for induced ventricular
tachyarrhythmias. Medtronic cardiac devices are designed to withstand exposure to ablation energy. To mitigate
risks, observe the following precautions:

●

Ensure that temporary pacing and defibrillation equipment is available.

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Avoid direct contact between the ablation catheter and the implanted system.

●

Position the return electrode patch so that the electrical current pathway does not pass through or near the
device and lead system.

●

Always monitor the patient during ablation with at least two separate methods, such as arterial pressure
display, ECG, manual monitoring of the patient’s rhythm (taking pulse) or monitor by some other means such
as ear or finger pulse oximetry, or Doppler pulse detection.

To avoid or mitigate the effects of oversensing, consider the following precautions:

●

Suspend tachyarrhythmia detection by using a magnet or a programmer. If a programmer is used and ablation
causes a device reset, the cardiac device resumes detection. After the ablation procedure, remove the magnet
or restore device parameters.

●

If appropriate for the patient, program the device to an asynchronous pacing mode (for example, DOO). After
the ablation procedure, restore device parameters.

Capsule endoscopy, pH capsule procedures – Capsule endoscopy is a procedure in which a capsule
containing a tiny camera is swallowed by the patient to take pictures of the patient’s digestive tract. Capsule
endoscopy and pH capsule procedures should pose no risk of electromagnetic interference.

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Dental procedures – Dental equipment, such as ultrasonic scalers, drills, and pulp testers, poses no risk of
electromagnetic interference. Keep a cardiac device at least 15 cm (6 in) away from magnets, such as magnets
found in dental office pillow headrests.

Diagnostic radiology (CT scans, fluoroscopy, mammograms, x-rays) – Diagnostic radiology refers to the
following medical procedures:

●

Computerized axial tomography (CT or CAT scan)

●

Fluoroscopy (an x-ray procedure that makes it possible to see internal organs in motion by producing a video
image)

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Mammograms

●

X-rays (radiography, such as chest x-rays)

Normally, the accumulated dose from diagnostic radiology is not sufficient to damage the device. If the device is
not directly exposed to the radiation beam, no risk of interference with device operation occurs. However, if the
device is directly in a CT scan beam, see the following precautions in “CT scan”. Similar interference may be
observed for some forms of high-intensity fluoroscopy.

CT scan – A CT scan is a computerized process in which two-dimensional x-ray images are used to create a
three-dimensional x-ray image. If the device is not directly in the CT scan beam, the device is not affected. If the
device is directly in the CT scan beam, oversensing may occur for the duration of time the device is in the beam.
If the device will be in the beam for longer than 4 s, to avoid or mitigate the effects of oversensing, consider the
following precautions:

●

Suspend tachyarrhythmia detection by using a magnet or a programmer. After completing the CT scan,
remove the magnet or restore device parameters.

●

If appropriate for the patient, program the device to an asynchronous pacing mode (for example, DOO). After
completing the CT scan, restore device parameters.

Diagnostic ultrasound – Diagnostic ultrasound is an imaging technique that is used to visualize muscles and
internal organs, their size, structures, and motion as well as any pathological lesions. It also is used for fetal
monitoring and to detect and measure blood flow. Diagnostic ultrasound, such as echocardiogram, poses no risk
of electromagnetic interference. For precautions about therapeutic ultrasound, see “Diathermy treatment
(including therapeutic ultrasound)”.

Diathermy treatment (including therapeutic ultrasound) – Diathermy is a treatment that involves the
therapeutic heating of body tissues. Diathermy treatments include high frequency, short wave, microwave, and
therapeutic ultrasound. Except for therapeutic ultrasound, do not use diathermy treatments on cardiac device
patients. Diathermy treatments may result in serious injury or damage to an implanted device and lead system.
Therapeutic ultrasound (including physiotherapy, high intensity therapeutic ultrasound, and high intensity focused
ultrasound), is the use of ultrasound at higher energies than diagnostic ultrasound to bring heat or agitation into the
body. Therapeutic ultrasound is acceptable if treatment is performed with a minimum separation distance of 15 cm
(6 in) between the applicator and the implanted device and lead system, as long as the ultrasonic beam is pointing
away from the device and lead system.

Electrolysis – Electrolysis is the permanent removal of hair by using an electrified needle (AC or DC) that is
inserted into the hair follicle. Electrolysis introduces electrical current into the body, which may cause oversensing.
Evaluate any possible risks associated with oversensing with the patient’s medical condition. To avoid or mitigate
the effects of oversensing, consider the following precautions:

●

Suspend tachyarrhythmia detection by using a magnet or a programmer. After completing electrolysis, remove
the magnet or restore device parameters.

●

If appropriate for the patient, program the device to an asynchronous pacing mode (for example, DOO). After
completing electrolysis, restore device parameters.

Electrosurgery – Electrosurgery (including electrocautery, electrosurgical cautery, Medtronic Advanced Energy
surgical incision technology, and hyfrecator) is a process in which an electric probe is used to control bleeding, to
cut tissue, or to remove unwanted tissue. Electrosurgery used on cardiac device patients may result in, but is not

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