Medtronic LNQ22 Reference Guide

LINQ II™ LNQ22

Medical Procedure and EMI Warnings, Precautions, and Guidance

Manual for Health Care Professionals

Caution: Federal law (USA) restricts this device to sale by or on the order of a physician.

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LINQ II, Medtronic

1 Medical procedure and EMI warnings, precautions, and guidance

1.1 Introduction

This manual is intended for physicians and other health care professionals who treat patients who have a
Medtronic LINQ II insertable cardiac monitor. To view this manual online or to download it, refer to the Medtronic
Manual Library at www.medtronic.com/manuals.

The “Warnings, precautions, and guidance for clinicians performing medical procedures” section of this document
is useful to health care professionals who perform medical procedures on patients with Medtronic insertable
cardiac monitor 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 LINQ II patient, interfere with a LINQ II insertable cardiac monitor (device), or permanently damage the device.

The “Warnings, precautions, and guidance related to electromagnetic interference (EMI)” section 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-procedure consultations.

For guidance on unusual or new medical procedures or potential EMI scenarios you are concerned about when
treating LINQ II patients that are not addressed in this manual, contact Medtronic as follows:

●

In the United States, contact a Medtronic representative or Medtronic Technical Services at
[e-mail] or [phone].

●

Outside the United States, contact a Medtronic representative.

Caution regarding concomitant device implants: – If the LINQ II patient has an implanted pacemaker or
defibrillator, the automatic detection of arrhythmia episodes in the LINQ II device may be affected by the paced
heart rhythm. To minimize the possibility of a Medtronic programmer’s programming head and telemetry interfering
with a pacemaker or defibrillator, do not hold either the Patient Assistant activator or the programming head directly
above an implanted device that was not manufactured by Medtronic while the programmer application is active.

1.2 Warnings, precautions, and guidance for clinicians performing medical procedures on LINQ II patients

The influence of medical equipment on LINQ II device performance varies considerably according to the type of
unit and energy levels employed. In situations where risks are known, the LINQ II device should be interrogated in
order to save the device data before medical procedures that may affect device data are performed. After the
medical procedure and at the patient’s and clinician’s earliest convenience, the patient’s LINQ II device should be
checked for proper function.

The following subsections provide warnings, precautions, and guidance for health care providers that perform the
specified medical procedures on LINQ II patients.

1.2.1 Ablation (RF ablation or microwave ablation)

Ablation is a surgical technique in which radiofrequency (RF) or microwave energy is used to destroy cells by
creating heat. Ablation may temporarily affect LINQ II device data collection, cause device electrical reset, or
damage the device. To avoid such effects, observe the following precautions:

●

The ablation equipment should not directly contact the LINQ II device.

●

Use short, intermittent, and irregular bursts at the lowest clinically appropriate energy levels.

If an electrical reset occurs, the patient’s LINQ II device health care provider should reprogram device parameters
as needed.

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1.2.2 Diagnostic radiology (x-rays, mammograms, CT scans, and fluoroscopy)

Normally, the accumulated dose from diagnostic radiology, such as from chest x-rays, is not sufficient to damage
the LINQ II device. If the device is not directly exposed to the radiation beam, no risk of interference with device
function occurs. However, the following precautions apply to mammograms, CT scans (if the device is directly in
a CT scan beam), and some forms of high-intensity fluoroscopy.

Mammography – Mammography involves compressing the breast between two plates in order to take various
x-ray views. During the mammography procedure, manipulation or angular stress of the LINQ II device between
the plates could cause tissue trauma, vascular trauma, or pain, or affect device sensing. Before scheduling a
mammogram, the cardiologist and mammography clinician should weigh the potential risks against the benefits
and evaluate other diagnostic options. To minimize device manipulation or angular stress that a mammography
procedure can cause, allow sufficient time for the LINQ II device pocket and incision to heal before performing a
mammography procedure.

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 patient undergoes a CT scan procedure and the LINQ II device is exposed
to the CT scan beam, oversensing may occur for the duration of time that the device is in the beam.

Fluoroscopy – Fluoroscopy is an x-ray procedure that makes it possible to see internal organs in motion by
producing a video image. Similar interference as described for CT scan may be observed for some forms of
high-intensity fluoroscopy.

1.2.3 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.

1.2.4 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 LINQ II patients. Diathermy treatments may result in serious injury or damage to the
LINQ II device. Therapeutic 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 LINQ II device. If you have specific concerns
about particular patient conditions and the use of diathermy, contact Medtronic.

1.2.5 Electrosurgery

Electrosurgery (including electrocautery, electrosurgical cautery, and Medtronic Advanced Energy surgical
incision technology) is a process in which an electric probe is used to control bleeding, to cut tissue, or to remove
unwanted tissue. Electrosurgery may temporarily affect LINQ II device data collection, cause device electrical
reset, or damage the device. To avoid such effects, observe the following precautions:

●

The electrosurgery equipment should not directly contact the LINQ II device.

●

Use short, intermittent, and irregular bursts at the lowest clinically appropriate energy levels.

If an electrical reset occurs, the patient’s LINQ II device health care provider should reprogram device parameters,
as needed.

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1.2.6 External defibrillation and cardioversion

External defibrillation and cardioversion are therapies that deliver an electrical shock to the heart to convert an
abnormal heart rhythm to a normal rhythm. Medtronic cardiac devices are designed to withstand exposure to
external defibrillation and cardioversion. While damage to a cardiac device from an external shock is rare, the
probability increases with increased energy levels. Use the lowest clinically appropriate energy. Do not place
defibrillation paddles directly over the LINQ II device, and try to avoid having the device between the paddles when
defibrillating. Defibrillation may lead to tissue damage, device reset, or loss of stored data. After defibrillation and
at the patient’s and clinician’s earliest convenience, the LINQ II device health care provider should check device
function. If an electrical reset occurs during external defibrillation or cardioversion, the LINQ II device health care
provider also needs to reprogram device parameters.

1.2.7 Hyperbaric therapy (including hyperbaric oxygen therapy, or HBOT)

Hyperbaric therapy is the medical use of air or 100% oxygen at a higher pressure than atmospheric pressure.
Hyperbaric therapies with pressures exceeding 4 ATA (approximately 30 m or 100 ft of seawater) may affect LINQ II
device function or cause device damage. To avoid or mitigate risks, do not expose LINQ II patients to pressures
exceeding 4 ATA.

1.2.8 Lithotripsy

Lithotripsy is a medical procedure that uses mechanical shock waves to break up kidney or gallbladder stones.
Lithotripsy can permanently damage the LINQ II device if it is at the focal point of the lithotripsy beam. If lithotripsy
is required, keep the focal point of the lithotripsy beam at least 5 cm (2 in) from the device. If lithotripsy is performed
closer than 5 cm (2 in) from the device, the LINQ II device health care provider should check device function at the
patient’s and clinician’s earliest convenience.

1.2.9 Magnetic resonance imaging (MRI)

An MRI is a type of medical imaging that uses magnetic fields to create an internal view of the body. LINQ II is an
MR Conditional device. If certain criteria are met and the warnings and precautions provided by Medtronic are
followed, patients with an MR Conditional device are able to undergo an MRI scan. For details on performing MRI
scans on a LINQ II device patient, contact the patient’s cardiologist or Medtronic to obtain the LINQ II MRI Technical
Manual or to get answers to your questions.

1.2.10 Radiation therapy

Exposing the LINQ II device to therapeutic levels of ionizing radiation (such as that produced by cobalt machines
or linear accelerators used for cancer treatment) may trigger inappropriate episode detection or corrupt the data
stored in memory. After radiation therapy and at the patient’s and clinician’s earliest convenience, the LINQ II
device health care provider should check device function. Cumulative radiation levels above 5 Gy may
permanently damage the device. Damage may not be immediately apparent.

1.2.11 Radiotherapy

Radiotherapy is a cancer treatment that uses radiation to control cell growth. Exposing the LINQ II device to direct
or scattered neutrons may cause electrical reset of the device, errors in device function, errors in diagnostic data,
or loss of diagnostic data. To help reduce the chance of electrical reset due to neutron exposure, deliver
radiotherapy treatment using photon beam energies less than or equal to 10 MV. The use of conventional x-ray
shielding during radiotherapy does not protect the device from the effects of the neutrons. If photon beam energies
exceed 10 MV, Medtronic recommends that the LINQ II device health care provider interrogate the device
immediately after radiotherapy treatment. If an electrical reset occurs, the patient’s LINQ II device health care
provider should reprogram device parameters, as needed. Electron beam treatments that do not result in neutron
production will not cause electrical reset of the device.

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1.2.12 Transcutaneous electrical nerve stimulators (TENS)

TENS therapy (including neuromuscular electrical stimulation or NMES) is a pain control technique that uses
electrical impulses passed through the skin to stimulate nerves. Using TENS equipment can affect the data stored
in the cardiac device.

1.2.13 Transurethral Needle Ablation (TUNA) therapy

Transurethral needle ablation is a surgical procedure used for benign prostatic hyperplasia (BPH) in which
precisely focused, conducted radiofrequency energy is used to ablate prostate tissue. LINQ II patients may
conditionally undergo procedures that use the Medtronic TUNA system. To avoid affecting LINQ II device function
when performing the TUNA procedure, position the return electrode on the lower back or lower extremity at least
15 cm (6 in) away from the LINQ II device.

1.3 Warnings, precautions, and guidance related to electromagnetic interference (EMI) for LINQ II patients

The LINQ II cardiac monitor is not affected by most household electrical items. However, the electromagnetic
energy fields of certain electrical items may temporarily affect the cardiac monitor’s ability to collect information
about the patient’s heart and can reduce the amount of data available for the clinic to analyze. By following simple
guidelines included in this section, the patient may avoid data collection problems related to electrical interference.
Any effects of electromagnetic energy fields on the heart monitor data will stop when the patient moves away from
the source of the electromagnetic energy field.

The following information is also provided to the patient in the LINQ II patient manual. The cardiology nurse or
doctor may want to review this information with the LINQ II patient. If you have any questions or concerns about
EMI, contact a Medtronic representative.

1.3.1 General guidelines for patients

Area restrictions – Before entering an area where signs are posted prohibiting persons with an implanted cardiac

device, such as a pacemaker, ICD, or cardiac monitor, consult with your doctor.

Proper grounding of electrical items – To avoid interference from electrical current that may leak from
improperly grounded electrical items and pass through the body, observe the following precautions:

●

Make sure that all electrical items are properly wired and grounded.

●

Make sure that electrical supply lines for swimming pools and hot tubs are properly installed and grounded
according to local and national electrical code requirements.

1.3.2 Wireless communication devices

Wireless communication devices – Wireless communication devices and accessories can interfere with the

function of cardiac devices. To avoid such interference, keep the following items at least 15 cm (6 in) away from your
cardiac device:

●

Cordless home telephones

●

Laptop or tablet computers, keyboards; network routers; MP3 players; eReaders; gaming consoles;
televisions, DVD/DVR players, and remote controls; wearable fitness monitors; smart watches

●

Headsets, headphones, and earbuds

●

Remote keyless entry and remote car starter devices

●

Remote controller of radio-controlled toys

●

Two-way walkie-talkies (less than 3 W)

For example, to avoid interference, do not carry a wireless device in a pocket over the cardiac device or in a
shoulder bag near the cardiac device. Note: Magnets in these wireless communication devices can interfere with
cardiac devices; however transmitters in these wireless communication devices are not likely to interfere with
cardiac devices.

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Mobile telephones – Mobile telephones, including cellular telephones and smartphones, are not likely to affect
cardiac devices. However, some accessories for mobile telephones contain magnets, such as cases with
magnetic clasps. Keep these accessories at least 15 cm (6 in) away from cardiac devices.

1.3.3 Household and hobby items with motors and other items that cause EMI

Household and hobby items that have motors or that generate electromagnetic energy fields could interfere with
your cardiac monitor. Keep your cardiac monitor at least 15 cm (6 in) away from the following items:

●

Handheld kitchen appliances such as electric mixers

●

Sewing machines and sergers

●

Personal care items such as corded hair dryers, corded electric shavers, electronic back massagers, or the
charging base stations of electric or ultrasonic toothbrushes

Here are other items that require special precautions. Keep your cardiac monitor the following minimum distances
away from these items:

Induction cooktops (when the heating zone is turned on) – At least 60 cm (24 in)

UPS (uninterruptible power source) up to 200 A – At least 30 cm (12 in). If the UPS is operating by battery

source, keep your cardiac monitor at least 45 cm (18 in) away.

Electronic pet fences or invisible fences (buried wire and indoor antenna) – At least 30 cm (12 in)

Home-use electric kilns – At least 60 cm (24 in)

Handheld metal detectors – At least 60 cm (24 in)

Boat motors (either electric trolling or gasoline-powered) – At least 30 cm (12 in)

Portable electric generators up to 20 kW – At least 30 cm (12 in)

Smart scales that measure body-mass index (BMI) – There is no minimum distance recommendation for

these scales, but they can affect the data stored in the cardiac monitor. Contact your clinician before using a BMI
scale.

1.3.4 Home power tools

Most home power tools should not affect cardiac monitors. Consider the following common-sense guidelines:

●

To avoid electrical shock, keep all equipment in good working order.

●

Be certain that plug-in tools are properly grounded or double insulated. Using a ground fault interrupter (GFI)
outlet is a good safety measure.

Some home power tools could affect cardiac monitor operation. To avoid interference, keep your cardiac monitor
the following minimum distances away from these tool and equipment types:

Electric yard and handheld power tools (plug-in and cordless) – At least 15 cm (6 in)

Soldering guns and demagnetizers – At least 30 cm (12 in)

Gasoline-powered tools and gasoline-powered yard equipment – Turn off the motor before making

adjustments or repairs to this equipment. When the motor is running, keep your cardiac monitor at least 30 cm
(12 in) away from components of the ignition system.

Car engine repair – Turn off the engine before making any car repairs or adjustments. When the engine is running,
keep your cardiac monitor at least 30 cm (12 in) away from components of the ignition system.

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1.3.5 Industrial equipment

After recovering from the LINQ II insertion procedure, you likely will be able to return to work, to school, or to your
daily routine. However, if you will be using or working near high-voltage equipment, sources of high electrical
current, magnetic fields, or other EMI sources that may affect device operation, consult with your doctor. You may
need to avoid using, or working near, the following types of industrial equipment:

●

Electric furnaces used in the manufacturing of steel

●

Induction heating equipment and induction furnaces, such as kilns

●

Industrial magnets or large magnets, such as those used in surface grinding and electromagnetic cranes

●

Dielectric heaters used in industry to heat plastic and dry glue in furniture manufacturing

●

Electric arc and resistance welding equipment

●

Broadcasting antennas of AM, FM, shortwave radio, and TV stations

●

Microwave transmitters
Note: Microwave ovens are unlikely to affect cardiac devices.

●

Power plants, large generators, and transmission lines

Note: Lower-voltage distribution lines for homes and businesses are unlikely to affect cardiac devices.

1.3.6 Radio transmitters

Determining a safe distance between the antenna of a radio transmitter and a cardiac device depends on many
factors such as transmitter power, frequency, and the antenna type. If the transmitter power is high or if the antenna
cannot be directed away from a cardiac device, you may need to stay farther away from the antenna. Refer to the
following guidelines for different types of radio transmitters:

Two-way radio transmitter (less than 3 W) – Keep a cardiac device at least 15 cm (6 in) away from the antenna.

Portable transmitter (3 to 15 W) – Keep a cardiac device at least 30 cm (12 in) away from the antenna.

Commercial and government vehicle-mounted transmitters (15 to 30 W) – Keep a cardiac device at least

60 cm (24 in) away from the antenna.

Other transmitters (125 to 250 W) – Keep a cardiac device at least 2.75 m (9 ft) away from the antenna. For
transmission power levels higher than 250 W, contact a Medtronic representative for more information.

1.3.7 Security systems

When passing through security systems, follow these precautions:

Electronic antitheft systems, such as in a store or a library, and point-of-entry control systems, such as
gates or readers that include radiofrequency identification (RFID) equipment – These systems should not

affect a cardiac device, but, as a precaution, do not linger near or lean against such systems. Simply walk through
these systems at a normal pace.

Airport, courthouse, and jail security systems – Given the short duration of security screening, it is unlikely that
metal detectors (walk-through archways and handheld wands) and full body imaging scanners (also called
millimeter wave scanners and three-dimensional imaging scanners) in airports, courthouses, and jails will affect
a cardiac device. When encountering these security systems, follow these guidelines:

●

Always carry your cardiac device ID card. If a cardiac device sets off a metal detector or security system, show
your ID card to the security operator.

●

Minimize the risk of temporary interference with your cardiac device while going through the security screening
process by not touching metal surfaces around any screening equipment.

●

Do not stop or linger in a walk-through archway; simply walk through the archway at a normal pace.

●

If a handheld wand is used, ask the security operator not to hold it over or wave it back and forth over your
cardiac device.

●

If you have concerns about security screening methods, show your cardiac device ID card to the security
operator, request alternative screening, and then follow the security operator’s instructions.

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Minneapolis, MN 55432
USA
www.medtronic.com
[phone]

Medtronic USA, Inc.

Toll-free in the USA (24-hour technical
consultation for physicians and medical
professionals)
Bradycardia: [phone]
Tachycardia: [phone]

Technical manuals

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M974770A001 A
2019-01-28