Medtronic MC1AVR1 Implant Manual

Micra™ AV MC1AVR1

MR Conditional dual chamber transcatheter pacing system with SureScan™ technology
(VDD)

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

The following list includes trademarks or registered trademarks of Medtronic in the United
States and possibly in other countries. All other trademarks are the property of their respective
owners.

Capture Management, Marker Channel, Medtronic, Micra, Quick Look, SureScan

Contents

1 System overview ..................................................... 5

1.1 Introduction ......................................................... 5

1.2 System description ................................................... 5

1.3 Indications for use ................................................... 9

1.4 Contraindications .................................................... 9

1.5 Pre-implant considerations ........................................... 10

1.6 Feature summary ................................................... 11

1.7 Pacing mode information ............................................. 12

1.8 Data security ....................................................... 14

2 Warnings, precautions, and potential adverse events .................. 15

2.1 General warnings and precautions .................................... 15

2.2 Explant and disposal under care ...................................... 17

2.3 Explant and disposal postmortem ..................................... 18

2.4 Handling and storage instructions ..................................... 18

2.5 Device operation .................................................... 19

2.6 Warnings, precautions, and guidance for clinicians performing medical

procedures on cardiac device patients ................................. 21

2.7 Warnings, precautions, and guidance related to electromagnetic

interference (EMI) for cardiac device patients ........................... 29

2.8 Physician training ................................................... 38

2.9 Potential adverse events ............................................. 38

2.10 Adverse events and clinical trial data ................................... 40

3 Drug information .................................................... 41

3.1 Mechanism of action ................................................ 41

3.2 Pharmacokinetics and metabolism .................................... 41

3.3 Mutagenesis, carcinogenicity, and reproductive toxicity ................... 41

4 Implant procedure ................................................... 43

4.1 Preparing for an implant .............................................. 43

4.2 Implanting the device ................................................ 47

4.3 Implanting a new Micra AV device in a patient with an existing Micra device .. 59

4.4 Retrieving and repositioning the device after the tether removal ............ 63

3

5 Product specifications ............................................... 68

5.1 Physical characteristics .............................................. 68

5.2 Electrical specifications .............................................. 69

5.3 Replacement indicators .............................................. 70

5.4 Projected service life ................................................ 71

6 Device parameters ................................................... 74

6.1 Emergency settings ................................................. 74

6.2 Pacing parameters .................................................. 74

6.3 Data collection setup parameters ...................................... 77

6.4 Test parameters .................................................... 78

6.5 Nonprogrammable parameters ....................................... 79

7 Packaging symbols and declaration of conformity ..................... 80

7.1 Declaration of compliance to standards ................................ 80

7.2 Explanation of symbols .............................................. 80

4

1 System overview

1.1 Introduction

This manual describes the Medtronic Micra™ AV Model MC1AVR1 MR Conditional dual
chamber transcatheter pacing system (VDD). It contains feature descriptions, indications
and contraindications, warnings and precautions, instructions for implanting the device,
quick reference specifications, and parameter tables.

The following manuals and documents also contain information about the device:

MRI technical manual – This manual provides MRI-specific procedures and warnings and
precautions.

Reference manual – This manual contains detailed information about the functionality of
Micra AV device features.

Programming guide – This manual explains how to use the programmer software to
conduct a patient session.

Radio regulatory compliance information – This document provides compliance
information related to the radio components of the device.

1.2 System description

The Medtronic Micra AV Model MC1AVR1 MR Conditional dual chamber, transcatheter
pacing system with SureScan technology is a programmable cardiac device that monitors
and regulates the patient’s heart rate by providing rate-responsive bradycardia pacing to the
right ventricle and AV synchrony based on the mechanical sensing of atrial activity.

The device senses both the electrical activity and the mechanical activity of the patient’s
heart using sensing and pacing electrodes and an accelerometer enclosed in a miniature
titanium capsule. It monitors the heart for bradycardia and AV synchrony. It also provides the
following features for patients:

●

The device responds to bradycardia by providing pacing therapy based on programmed
pacing parameters.

●

The device provides AV synchrony based on sensed mechanical activity in the atrium.

●

The device provides diagnostic and monitoring information to evaluate device
performance and to provide the best possible patient care.

5

Figure 1. Implanted Micra AV Model MC1AVR1 transcatheter pacing system

1 The device implant location in the right ventricle

The MRI SureScan feature permits a mode of operation that allows a patient with a SureScan
system to be safely scanned by an MRI machine while the device continues to provide
appropriate pacing. When programmed to On, MRI SureScan operation disables all
user-defined diagnostics. Before performing an MRI scan, refer to the MRI technical manual.

The users of this device include medical professionals (physicians, nurses, technicians, and
their supporting staff) trained in surgery, cardiology, radiology, and magnetic resonance
(MR) technology and able to implement the procedures documented in the instructions for
use for this device.

The components of the Micra AV Model MC1AVR1 transcatheter pacing system are shown
in the following figure:

6

Figure 2. System components

VVI

Medtronic Programmer Micra delivery catheter

Implantable device

1.2.1 Intended use

Transcatheter pacing systems are sterile, single-use only, active implantable medical
devices that are implanted in patients by health care professionals trained in cardiology.
Transcatheter pacing systems are intended to improve cardiac output, prevent symptoms of
and protect against arrhythmias related to cardiac impulse formation or conduction
disorders by providing pacing therapy to the heart.

1.2.2 Usage environments

The device is intended to be used in the following environments and conditions:

●

The device will be implanted in a properly equipped, staffed, and sterile surgical
environment. Implant will take place under standard surgical protocols and in the patient
population for which the device is indicated.

●

Post-surgical patient and device follow-up care will take place in a properly equipped
and staffed cardiology clinic or office.

●

MRI procedures for patients with this device will take place in a properly equipped and
staffed MR facility, and in consideration of the conditions and requirements described in
the MRI technical manual.

7

●

After having an implant, patients may resume their lives at home, at work, and in other
environments in consideration of physician orders, and in consideration of the advice
and restrictions documented in this manual and in the patient literature.

1.2.3 System components and accessories

Contents of sterile package – The sterile package contains 1 implantable transcatheter

pacing system, which includes the implantable device and delivery catheter system.
The Micra AV transcatheter pacing system is sterilized with ethylene oxide gas and

packaged in a pouch that contains a sterile aseptic tray. The tray is designed to ease the
placement of the pacing system in the sterile field. For the pacing system to be sterile, the
pouch must not be damaged or opened. The outer surfaces of the pouch are nonsterile and
must not be placed in the sterile field.

For instructions to open the sterile package, see Section 4.1.5, “How to open the sterile
package”, page 45.

Implantable device – The Micra AV Model MC1AVR1 is a dual chamber transcatheter
pacing system that provides AV synchronous pacing and bipolar sensing and pacing in the
right ventricle. The device has an active fixation mechanism consisting of 4 electrically
inactive tines designed to anchor the device in the cardiac tissue at the implant location in the
right ventricle.

MRI SureScan feature – Patients with an implanted Micra AV Model MC1AVR1 pacing
system can undergo an MRI scan if the system meets the requirements described in the
Micra AV Model MC1AVR1 MRI technical manual. The MRI SureScan pacing feature allows
the patient to be safely scanned while the device continues to provide appropriate pacing.

Before performing an MRI procedure, refer to the Micra AV Model MC1AVR1 MRI technical
manual for important information about procedures and MRI-specific contraindications,
warnings, and precautions.

Device delivery catheter system – The Micra AV delivery catheter system consists of the
following parts:

●

A delivery catheter designed to carry, deliver, and position the device for implant in the
right ventricle by accessing this chamber through the femoral vein. The delivery catheter
has a steerable, flexible shaft with a rigid distal end that contains a device cup to hold the
device and a recapture cone to retrieve it. The delivery catheter is compatible with a

7.8 mm (23 Fr) introducer sheath that is 56 cm (22 in) long or longer, such as the
Medtronic Micra Introducer.

●

A handle with controls to navigate the delivery catheter and deploy the device. The
handle also provides a tether designed as an aid to test the device fixation and to
recapture and reposition the device for proper fixation during the implant procedure.

Programmer and software – The Medtronic programmer and software are used to
program the device for implant testing and patient follow-up sessions. The use of a
Medtronic programming head is required for communication between the device and the

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programmer. Programmers from other manufacturers are not compatible with Medtronic
devices but will not damage Medtronic devices.

1.3 Indications for use

Micra AV Model MC1AVR1 is indicated for use in patients who have experienced one or
more of the following conditions:

●

Paroxysmal or permanent high-grade AV block in the presence of AF

●

Paroxysmal or permanent high-grade AV block in the absence of AF, as an alternative to
dual chamber pacing, when a dual-chamber transvenous pacing system is considered
difficult, high risk, or not deemed necessary for effective therapy

●

Symptomatic bradycardia-tachycardia syndrome or sinus node dysfunction (sinus
bradycardia or sinus pauses), as an alternative to atrial or dual chamber pacing, when a
dual-chamber transvenous pacing system is considered difficult, high risk, or not
deemed necessary for effective therapy

The device is also indicated for VDD pacing in patients with adequate sinus rates who may
benefit from maintenance of AV synchrony. The Micra AV device provides AV synchronous
ventricular pacing similar to a transvenous VDD system. The implanted device depends on
the appropriate sensing of atrial mechanical signals to achieve AV synchrony. The level of AV
synchrony may vary in individual patients and may not be predictable prior to implant.

Rate-responsive pacing is indicated to provide increased heart rate appropriate to
increasing levels of activity.

The device is designed to be used only in the right ventricle.

1.4 Contraindications

Micra AV Model MC1AVR1 devices are contraindicated for use in the following situations:

●

If an implanted inferior vena cava filter is present

●

If a mechanical tricuspid valve is present

●

If another implanted cardiac device providing active cardiac therapy may interfere with
the sensing performance of the Micra device

●

If another implanted device would interfere with the implant of the Micra device in the
judgment of the implanting physician

●

If femoral venous anatomy is unable to accommodate a 7.8 mm (23 Fr) introducer sheath
or implant on the right side of the heart (for example, due to obstructions or severe
tortuosity)

●

If morbid obesity prevents the implanted device from obtaining adequate telemetry
communication within 12.5 cm (4.9 in)

●

If known intolerance to heparin or the tissue contacting materials in the device exists

●

If sensitivity to contrast media cannot be adequately premedicated

●

If the steroid dose from this device cannot be tolerated

9

For the MRI contraindications for patients with a Micra AV MRI device, refer to the Micra AV
MRI technical manual.

1.5 Pre-implant considerations

The Micra AV device is intended to provide AV synchrony at rest and VVIR pacing during
periods of high patient activity. Synchronous ventricular pacing using sensing of atrial
mechanical contraction may not provide continuous AV synchrony. Device-mediated AV
synchrony can vary depending on patient condition and activity levels, and it can be limited
at high sinus rates. During periods of intermittent AV synchrony, the device will provide
ventricular pacing support with increased potential for pacing rate variability.

The decision to implant the Micra AV device should consider the benefits of leadless pacing
versus the patient’s need for continuous AV synchrony.

Some patients will not benefit from the AV synchronous (VDD) mode. Patients with the
following conditions should be considered for a dual-chamber transvenous pacing system:

●

Sinus node dysfunction

●

High sinus rates requiring atrial tracking

●

Weak atrial contraction

●

Symptoms during loss of AV synchrony

●

Frequent premature atrial or ventricular contractions where atrial tracking is required
immediately after the premature beat

Patient evaluation for the implant of Micra AV Model MC1AVR1 should include that the
Micra AV device is not intended to be removed following the End of Service (EOS) condition.

Patient evaluation for the implant of Micra AV Model MC1AVR1 should include the following
consideration about a concomitant implant with a neurostimulator:

Concomitant neurostimulator and cardiac device implants – Some patients have
medical conditions that require the implant of both a neurostimulator and a cardiac device
(for example, a pacemaker, a defibrillator, or a monitor). In this case, physicians (for example,
a neurologist, a neurosurgeon, a cardiologist, and a cardiac surgeon) involved with either
device should contact Medtronic Technical Services or their Medtronic representative
before implanting the patient with the second device. Based on the particular devices that
the physicians have prescribed, Medtronic can provide the necessary precautions and
warnings related to the implant procedure. For information about how to contact Medtronic,
see the telephone numbers and addresses provided on the back cover of this manual.

Note: The Micra AV device has not been tested with active coexisting devices.

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1.6 Feature summary

For a list of the features that are enabled at shipping, see Chapter 6, “Device parameters”,
page 74.

1.6.1 Pacing features

Auto PVARP – This feature adjusts the post-ventricular atrial refractory period (PVARP) in

VDD mode in response to changes in the patient’s heart rate or pacing rate. PVARP is longer
at lower tracking rates to prevent pacemaker-mediated tachycardia and shorter at higher
rates to maintain 1:1 tracking.

Capture Management – This feature monitors and manages pacing thresholds in the right
ventricle to ensure that the myocardium is consistently captured in consideration of
changing patient conditions.

Atrial mechanical sensing – The atrial mechanical sensing feature interprets mechanical
activity that is generated by the cardiac cycle as signals. These signals include a signal for
atrial contraction. If necessary, the device delivers a synchronous ventricular pace following
an atrial contraction signal.

MRI SureScan – This feature allows patients with an implanted MRI SureScan device to
have a safe MRI procedure if the requirements provided in the MRI technical manual are
followed.

Mode switch – The device provides 2 types of mode switch:

●

Activity Mode Switch engages when the device is programmed to the VDD pacing
mode but patient activity raises the intrinsic heart response to a rate that is better paced
by a rate-responsive pacing mode.

●

AV Conduction Mode Switch engages when the device is programmed to the VDD
pacing mode but switches to the VVI pacing mode in response to consistent intrinsic AV
conduction.

Noise reversion – The noise reversion operation allows the device to continue pacing the
heart while blocking oversensing otherwise caused by external electromagnetic
interference.

Rate Hysteresis – This feature promotes intrinsic activity below the programmed Lower
Rate. It prevents the device from overriding slow, but appropriate, intrinsic rhythms that may
develop from extended periods of inactivity, such as sleep.

Rate Profile Optimization – Rate Profile Optimization ensures that the Rate Response
feature provides appropriate pacing for the full range of patient activities. It monitors the
patient’s daily sensor rate profile and adjusts the rate response curves over time to achieve
a prescribed target.

Rate Response – This feature, also known as rate-responsive pacing, varies the device
pacing rate in response to the patient’s physical activity as detected by the activity sensor of
the device.

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Rate Smoothing – This feature improves AV synchrony in cases of intermittent atrial
mechanical undersensing.

Sensed AV – This pacing feature helps to optimize AV synchrony in the VDD pacing mode,
where you can program the interval between an atrial mechanical sense and a ventricular
pace.

Tracking Check – This feature operates when the device paces in VDD mode. Tracking
Check identifies and controls undesired device pacing above the sinus rate, including
device-induced tachycardias, due to atrial oversensing or external mechanical noise.

1.6.2 Monitoring and follow-up features

Atrial sensing setup – This feature is an automated post-implant process that collects atrial

mechanical sensing data and then sets the atrial sensing parameters to patient-specific
values, based on the collected data.

Device diagnostics – The device collects information on device performance over time.
The following metrics are included:

●

Battery voltage

●

Remaining device longevity

●

Electrode impedance trend

●

Capture threshold trend

●

R-wave amplitude trend

●

A4 amplitude trend

Holter telemetry – This function allows the implanted device to transmit an EGM with
marker telemetry continuously for up to 24 hours, regardless of the use of the programming
head. Enabling Holter telemetry results in a higher consumption of the device battery. Use of
a customized Holter monitor (provided by Medtronic) is required for monitoring the EGM.

Rate Histogram – This feature provides a programmer screen and a printable report of
graphs that present ventricular and atrial ventricular event data stored by the device.

1.7 Pacing mode information

Pacemaker modes are described using the NBG code. The five-letter NBG code, named
after The North American Society of Pacing and Electrophysiology (NASPE) and the British
Pacing and Electrophysiology Group (BPEG), describes the operation of implantable pulse
generators. The NBG code, which supersedes the ICHD Code, is described in Table 1.

12

Table 1. The Revised NASPE/BPEG Generic Code for antibradycardia pacing

Position: I II III IV V

Category: Chamber(s)

Paced

O = None
A = Atrium
V = Ventricle
D = Dual
(A + V)

Chamber(s)
Sensed

O = None
A = Atrium
V = Ventricle
D = Dual
(A + V)

Response to
Sensing

O = None
T = Trig­gered
I = Inhibited
D = Dual

Rate Modu­lation

O = None
R = Rate
modulation

Multisite
Pacing

a

O = None
A = Atrium
V = Ventricle
D = Dual
(A + V)

(T + I)

Manufactur-

ers’ designa-

S = Single
(A or V)

b

S = Single
(A or V)

b

tion only:

a

Medtronic devices do not use the Multisite Pacing code.

b

The programmer displays A or V (not S) for chambers paced and sensed.

1.7.1 Pacing modes available in Micra AV Model MC1AVR1 dual chamber

pacemaker

VDD and VDI modes – In the VDD mode, the device uses the accelerometer to mimic dual

chamber sensing by sensing atrial mechanical activity instead of atrial electrical activity. The
ventricle is paced based on atrial sensed events to promote AV synchrony at lower intrinsic
rates. In the VDI mode, atrial activity is sensed as it is in the VDD mode, but the ventricle is
paced at the programmed lower rate, regardless of intrinsic events.

VVIR and VVI modes – In the VVIR mode and the VVI mode, the ventricle is paced if no
intrinsic ventricular events are sensed before the current pacing interval ends. Pacing occurs
at the sensor rate in the VVIR mode and at the programmed lower rate in the VVI mode.

VOO mode – The VOO mode provides ventricular pacing at the programmed lower rate with
no inhibition by intrinsic ventricular events. In the VOO mode, no ventricular sensing occurs.

ODO mode – The ODO mode senses atrial mechanical activity and ventricular electrical
activity. The ODO mode turns off pacing outputs, but it allows the clinician to see intrinsic AV
synchrony.

OVO mode – The OVO mode does not deliver ventricular pacing outputs, regardless of the
intrinsic rate. The OVO mode is intended only for those situations where the clinician wants
to turn off bradycardia pacing outputs from the device.

Device Off mode – In the Device Off mode, the device does not pace or sense the heart. The
Device Off mode is intended only for those situations where the clinician wants to turn off
bradycardia pacing and sensing from the device.

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1.8 Data security

Medtronic has designed safeguards to protect patient information and device data for
Micra AV transcatheter pacemakers.

Inductive telemetry communication is used through a Medtronic programming head to a
Medtronic clinician programmer to interrogate and program the device. Inductive telemetry
is short-range communication that protects patient information and device data.

If you experience a cybersecurity event, or if you believe that you have identified a potential
security vulnerability involving a Medtronic Micra AV transcatheter pacemaker, consult the
Medtronic Coordinated Disclosure Process web site at https://www.medtronic.com/security
to report your concerns.

14

2 Warnings, precautions, and potential adverse events

2.1 General warnings and precautions

Antibiotic prophylaxis with dental procedures – Due to the lack of long-term, chronic

human experience, consider the use of prophylactic antibiotics prior to dental procedures to
reduce the risk of endocarditis.

Anti-coagulation – Appropriate anticoagulation therapy should be administered to reduce
potential thrombosis.

Anticoagulant agents, antiplatelet agents, and contrast media – Precautions should
be taken before administering anticoagulant agents, antiplatelet agents, or contrast media in
patients with known hypersensitivity to these agents.

Dexamethasone acetate use during pregnancy – Dexamethasone acetate has been
shown to be teratogenic in many species when given in doses equivalent to the human dose.
There are no adequate and well-controlled studies in pregnant women. Dexamethasone
acetate should be used during pregnancy only if the potential benefit justifies the potential
risk to the fetus. Studies in mice, rats, and rabbits have shown that adrenocorticoids increase
the incidence of cleft palate, placental insufficiency, and spontaneous abortions, and can
decrease the intrauterine growth rate.

Electrical isolation during implant – Do not allow the patient to have contact with
grounded electrical equipment that might produce electrical current leakage during implant.
Electrical current leakage may induce tachyarrhythmias that may result in the patient’s
death.

MRI conditions for use – Before an MRI scan is performed on a patient implanted with the
Micra AV MRI SureScan device, the cardiology and radiology professionals involved in this
procedure must understand the requirements specific to their tasks. For information about
MRI-specific warnings and precautions, refer to the Medtronic MRI technical manual
provided for this device.

External defibrillation equipment – Keep external defibrillation equipment nearby for
immediate use during the implant procedure, or whenever arrhythmias are possible or
intentionally induced during post-implant testing.

Mechanical vibrations in daily living – Patient activities and environments which present
mechanical vibrations to the patient can interfere with the mechanical sensing of atrial
contractions. This can result in loss of AV synchrony.

Multiple devices – The use of deactivated Micra devices in situ and an active Micra device,
or an active transvenous pacemaker or defibrillator, has not been clinically tested to
determine whether EMI or physical interaction is clinically significant. Bench testing
supports that implantation of an active Micra device, or an active transvenous pacemaker or

15

defibrillator, next to an inactivated Micra device is unlikely to cause EMI or physical
interaction. Post-approval studies are planned to characterize risks of co-implanted,
deactivated Micra devices. Currently recommended end of device life care for a Micra device
may include the addition of a replacement device with or without explantation of the Micra
device, which should be turned off.

Pacing thresholds following external defibrillation – Higher pacing threshold can
develop following external defibrillation. Higher pacing thresholds can cause loss of capture.

Patient’s age and medical condition – The patient’s age and medical condition should be
considered by physicians and patients as they select the pacing system, mode of operation,
and implant technique best suited to the individual.

Prosthetic tricuspid valve – Use caution when implanting a Micra AV device in a patient
with a prosthetic tricuspid valve to avoid valve damage. During device implant, visualizing
the prosthetic valve using the LAO fluoroscopic view can aid in limiting interaction with the
valve leaflets.

Steroid use – It has not been determined whether the warnings, precautions, or
complications usually associated with injectable dexamethasone acetate apply to the use of
this highly localized, controlled-release device. For a list of potential adverse effects, refer to
the Physicians’ Desk Reference.

Temporary pacing – For patients with left bundle branch block: recognition of the inherent
risk of complete heart block related to catheter and lead manipulation in the right ventricle is
important. Consider insertion of temporary pacing capabilities before a Micra implant.

Temporary high-rate pacing – High-rate stimulation of the ventricle can result in ventricular
tachycardia or fibrillation. Temporary high-rate pacing should be applied only under careful
patient monitoring and control.

Right ventricular apical pacing – Right ventricular apical pacing may be associated with
an increased risk of atrial fibrillation, left ventricular dysfunction, and congestive heart failure.

Nursing mothers – Systemically administered corticosteroids appear in human milk and
could suppress growth, interfere with endogenous corticosteroid production, or cause other
untoward effects in nursing infants. Owing to the potential for serious adverse reactions in
nursing infants from corticosteroids, a decision should be made whether to discontinue
nursing or to use the device, taking into account the importance of the device and the drug
to the mother.

Drug component description – The active ingredient in the device electrode is
dexamethasone acetate [9-Fluoro-11β,
17,21-trihydroxy-16α-methylpregna-1,4-diene-3,20-dione 21-acetate]. The structural
formula for this steroid is as follows:

Dexamethasone acetate (DXAC) - C24H31FO

6

16

Figure 3. Structure of dexamethasone acetate (DXAC)

The target dosage of dexamethasone acetate in this device is 272 µg.

Cautions:

●

Drug interactions of dexamethasone acetate with this device have not been studied.

●

Before implanting this device, consider the total patient exposure to dexamethasone
acetate.

2.2 Explant and disposal under care

Consider the following information about the explant and disposal of the device:

End of Service (EOS) – The Micra AV device is not intended to be removed following the
End of Service (EOS) condition.

Note: Removal of the Micra AV device may be difficult because of its deeper implant site in
the heart and the development of fibrotic tissue. If removal of the device is required, refer the
patient to a medical center that has expertise in the removal of implanted leads (particularly
with cardiac surgery backup) or call a Medtronic representative for more information.

Return mailer kits – Contact Medtronic for return mailer kits to return explanted devices for
analysis and disposal. See the back cover for addresses.

17

2.3 Explant and disposal postmortem

Postmortem – The Micra AV device is not intended to be explanted postmortem. If the

device is subjected to cremation, no technical difficulties or significant emissions are
expected. In some countries, explanting battery-operated implantable devices postmortem
is mandatory because of environmental concerns. Check the local regulations about
battery-operated implantable devices and environmental disposal laws.

Device malfunction – If the Micra AV device is removed because of a malfunction, return it
to Medtronic for analysis and disposal. Use the Product Information Report to return
explanted devices. See the back cover of this manual for Medtronic phone numbers and
mailing addresses.

Medtronic implantable devices are intended for single use only. Do not resterilize and
reimplant explanted devices.

2.4 Handling and storage instructions

Carefully observe these guidelines when handling or storing the device.

2.4.1 Device handling

Checking and opening the package – Before opening the sterile pouch, which is the

sterile barrier, visually check for any signs of damage that might invalidate the sterility of the
package contents.

Dropped device – Do not implant the device if it is dropped on a hard surface from a height
of 30 cm (12 in) or more after it is removed from its packaging.

If the package is damaged – The device packaging consists of a sterile barrier pouch,
aseptic tray, retainer cover, and protective clamshell. If the sterile barrier pouch is wet,
punctured, opened, or damaged, do not use the device or delivery catheter system. If any
information on the outer package or the sterile package is defaced or damaged so that the
information is illegible, do not use the device or delivery catheter system. Return the device
and delivery catheter system to Medtronic because the integrity of the sterile packaging or
the device functionality might be compromised. This device and delivery catheter system are
not intended to be resterilized.

If the printed manual is illegible – If this manual is supplied in its printed form and any part
of it is illegible, contact a Medtronic representative to request a replacement manual.

Sterilization – Medtronic has sterilized the package contents with ethylene oxide before
shipment. This product is for single use only and is not intended to be resterilized.

Device temperature – Allow the device to reach room temperature before it is programmed
or implanted. Device temperature above or below room temperature may affect initial device
function.

18

Handle with care – When handling the transcatheter pacing system, do not allow the
delivery catheter to whip the implantable device against hard surfaces. If this action occurs
inside or outside of the sterile field, do not implant the device.

Handling the steroid tip – Avoid reducing the amount of steroid available before implanting
the device. Reducing the available amount of steroid may adversely affect low-threshold
performance.

Do not allow the electrode surface to come into contact with surface contaminants.

Device fixation tines – Do not retract the device fixation tines all the way into the device cup
until you are ready to insert the delivery catheter system into the introducer. Unlike the helix
electrode of an active fixation lead, the device tines do not require pre-implant exercise.
Excessively retracting the device tines into the device cup before implant could adversely
affect their fixation performance.

“Use by” date – Do not implant the device after the “Use by” date because the battery
longevity could be reduced.

Single use – This product is intended for single use only. Do not resterilize and re-implant
the explanted product.

2.4.2 Device storage

Avoid magnets – To avoid damaging the device, store the device in a clean area away from

magnets, kits containing magnets, and any sources of electromagnetic interference.

Temperature limits – Store the transcatheter pacing system package at 25°C (77°F).
Excursions from this storage temperature are permitted in the range of 15 to 30°C (59 to
86°F). See the United States Pharmacopeia (USP) Controlled Room Temperature.
According to USP excursion conditions, transient spikes up to 40°C (104°F) are permitted,
as long as they do not exceed 24 hours.

2.5 Device operation

Accessories – Use this device only with accessories, parts subject to wear, and disposable

items that have been tested to technical standards and found safe by an approved testing
agency.

Battery depletion – Carefully monitor device longevity by checking battery voltage and
replacement indicators. Battery depletion eventually causes the device to stop functioning.

Device status indicators – If any of the device status indicators (for example, Electrical
Reset) are displayed on the programmer after interrogating the device, inform a Medtronic
representative immediately. If these device status indicators are displayed, therapies may
not be available to the patient.

19

Elective Replacement Indicator (ERI) – The programmer displays the ERI indicator when
the device battery reaches the ERI condition. When the ERI indicator is displayed, implant
a new device immediately.

Electrical reset – Electrical reset can be caused by exposure to temperatures below –18°C
(0°F) or strong electromagnetic fields. Advise patients to avoid strong electromagnetic
fields. Observe temperature storage limits to avoid exposure of the device to cold
temperatures. If a partial reset occurs, pacing resumes in the programmed mode with many
of the programmed settings retained. If a full reset occurs, the device operates in VVI mode
at 65 bpm. Electrical reset is indicated by a programmer warning message that is displayed
immediately upon interrogation. To restore the device to its previous operation, it must be
reprogrammed. Inform a Medtronic representative if your patient’s device has reset.

End of Service (EOS) indicator – The programmer displays an EOS indicator when the
device battery no longer has adequate capacity to provide therapy to the patient and the
device has reached the End of Service condition. When the battery reaches the EOS
condition, the device deactivates pacing permanently.

Longevity estimate near RRT – As the device approaches the RRT condition, the longevity
estimate is not updated during a programming session. It is instead updated every day at
00:00 (midnight). These daily longevity estimates can be incorrect if the pacing burden
changes significantly for the patient.

Pacing and sensing safety margins – Provide an adequate safety margin when selecting
values for pacing amplitude, pacing pulse width, and sensitivity parameters.

Programmers – Use only Medtronic programmers and application software to
communicate with the device. Programmers and software from other manufacturers are not
compatible with Medtronic devices.

Rate-responsive mode – Do not program the rate-responsive mode for patients who
cannot tolerate rates above the programmed Lower Rate. The rate-responsive mode may
cause discomfort for those patients.

Recommended Replacement Time (RRT) indicator – The programmer displays the RRT
indicator when the device battery reaches the RRT condition. If the programmer displays the
RRT indicator, schedule an appointment with the patient to implant a new device.

RV Capture Management – RV Capture Management does not adjust ventricular output to
a value greater than 5.0 V.

Shipping values – Do not use shipping values or nominal values for pacing amplitude and
sensitivity without verifying that the values provide adequate safety margins for the patient.

2.5.1 Pacemaker-dependent patients

Manual sensing test – Before starting the sensing test, select a temporary pacing rate that

is likely to allow intrinsic sensed events and may be well tolerated by the patient. If the patient
shows poor tolerance to the selected pacing rate when the test is in progress, tap STOP to
stop the test. To complete this test, the device must detect 2 consecutive ventricular sensed

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events with an interval of at least 500 ms (a heart rate of 120 bpm or slower) between them.
If such an interval is not identified after 10 s, the device stops the test. If a pacing rate suitable
to the patient is not available to select, consider omitting the sensing test from the device
measurement tests.

See the Micra AV SW044 Programming Guide for more information.

2.6 Warnings, precautions, and guidance for clinicians

performing medical procedures on cardiac device patients

This section is intended for physicians and other health care professionals who perform
medical procedures on patients with Medtronic implanted transcatheter pacemakers 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 a Medtronic implanted transcatheter pacemaker, or
permanently damage the device. This section also lists some common medical procedures
that pose no risk.

For guidance on medical procedures that are not addressed in this section, contact your
Medtronic representative.

The following table defines the acceptability for EMI from medical procedures and
equipment to patients with a Medtronic Micra AV transcatheter pacemaker.

Table 2. Acceptability of medical equipment and procedures for patients with an implanted transcatheter pacemaker

Acceptability Acceptability criteria

Acceptable The equipment and procedure have a low potential for EMI

with an implanted device, and they are safe if the equip­ment is in proper working condition and used as intended.

Acceptable with precau­tions

Not recommended The equipment and procedure have a high potential for

Note: The off-label use of any medical equipment or procedure described in this document

voids these acceptability criteria.

The equipment and procedure have some potential for EMI
with an implanted device. You can mitigate the effects of
the EMI if the equipment is in proper working condition and
used as intended, and if you follow the precautions in this
document.

EMI with an implanted device, and they are not safe. You
cannot mitigate the effects of the EMI.

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2.6.1 Ablation

There are 2 types of ablation: cryogenic ablation and radiofrequency (RF) or microwave
ablation.

Cryogenic ablation – Acceptable. Cryogenic ablation is indicated for the treatment of
atrial fibrillation. This procedure creates lesions in the cardiac tissue near the pulmonary
veins with cryothermal energy (pressurized liquid nitrous oxide).

Radiofrequency (RF) or microwave ablation – Acceptable with precautions. RF or
microwave ablation is a surgical technique in which energy creates heat to destroy cells.
Common types of ablation include, but are not limited to, intracardiac ablation and
endometrial ablation.

RF or microwave ablation used for cardiac device patients can result in, but is not limited to,
ventricular tachyarrhythmias, oversensing, unintended tissue damage, or unintended
device function.

Observe the following precautions when you administer RF or microwave ablation to a
patient with a transcatheter pacemaker:

●

Make sure that temporary pacing and defibrillation equipment is available.

●

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

●

Consider using at least 2 methods to monitor the patient during ablation. These methods
can include arterial pressure display, ECG, manual monitoring of patient rhythm (taking
pulse), ear or finger pulse oximetry, or Doppler pulse detection.

2.6.2 Capsule endoscopy

Contact Medtronic Technical Services. Capsule endoscopy, also known as video

capsule endoscopy, uses an ingestible digital camera that captures a video record of the
patient’s digestive tract. The camera is in a capsule with light-emitting diodes, a battery, and
a transmitter. Transmission of the video data occurs in short bursts of radiofrequency energy,
approximately 2 per s, for an 8-hour diagnostic period.

Note: Contact Medtronic Technical Services to confirm that your capsule endoscopy system
is safe for your patient.

2.6.3 Dental equipment

Acceptable with precautions. Dental procedures that use equipment such as apex

locators, ultrasonic scalers, drills, and pulp testers, pose no potential for EMI with an
implanted transcatheter pacemaker.

Accessories, such as office pillows or headrests, can contain magnets that can affect
sensing in an implanted transcatheter pacemaker. Keep an implanted transcatheter
pacemaker at least 15 cm (6 in) from these magnets.

Note: See “Electrosurgery” for guidance with electrosurgery used in periodontal surgery.

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

Diagnostic radiology includes the following procedures: computerized axial tomography (CT
or CAT scan), fluoroscopy, mammograms, and x-rays.

Normally, the accumulated dose of radiation from diagnostic radiology is insufficient to
damage an implanted transcatheter pacemaker. If the implanted transcatheter pacemaker
is not directly in the radiation beam, there is no potential for EMI, except where noted here.

CT scan – Acceptable with precautions. Oversensing can occur only when the implanted
transcatheter pacemaker is directly in the CT scan beam.

Fluoroscopy at < 1 cGy/min – Acceptable. Fluoroscopy at < 1 cGy/min generates
insufficient EMI to affect an implanted transcatheter pacemaker.

Fluoroscopy at ≥ 1 cGy/min – Not recommended. EMI from fluoroscopy at ≥ 1 cGy/min
can cause oversensing in an implanted transcatheter pacemaker.

Mammography – Acceptable. Mammography generates insufficient EMI to affect an
implanted transcatheter pacemaker.

X-ray – Acceptable. X-rays generate insufficient EMI to affect an implanted transcatheter
pacemaker.

2.6.5 Diagnostic ultrasound

Acceptable. Diagnostic ultrasound is an imaging technique that visualizes muscles and

internal organs, their size, structures, and motion, as well as any pathological lesions. It can
also monitor a fetus, and it can detect and measure blood flow. Diagnostic ultrasound
generates insufficient EMI to affect an implanted transcatheter pacemaker. For precautions
about therapeutic ultrasound, see “Diathermy (3 types)”.

2.6.6 Diathermy (3 types)

Diathermy involves the therapeutic heating of body tissues. There are 3 types of diathermy:
shortwave diathermy, microwave diathermy, and ultrasonic diathermy, also known as
therapeutic ultrasound. Shortwave diathermy or microwave diathermy can cause serious
injury, or they can damage an implanted transcatheter pacemaker. Do not use shortwave
diathermy or microwave diathermy. Ultrasonic diathermy is acceptable with precautions.

Shortwave diathermy – Not recommended. Shortwave diathermy can cause serious
patient injury. It can damage an implanted transcatheter pacemaker. Do not perform
shortwave diathermy on patients who have an implanted transcatheter pacemaker.

Microwave diathermy – Not recommended. Microwave diathermy can cause serious
patient injury. It can damage an implanted transcatheter pacemaker. Do not perform
microwave diathermy on patients who have an implanted transcatheter pacemaker.

Therapeutic ultrasound – Acceptable with precautions. Therapeutic ultrasound
(including physiotherapy, high intensity therapeutic ultrasound, and high intensity focused

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ultrasound) uses ultrasound at higher energies than diagnostic ultrasound to bring heat or
agitation into the body. Therapeutic ultrasound does not produce EMI fields capable of
inducing significant energy levels; however, the mechanical energy can physically damage
internal device components.

Therapeutic ultrasound is acceptable with a minimum separation distance of 15 cm (6 in)
between the applicator and the implanted transcatheter pacemaker. Also, point the
ultrasonic beam away from the device.

2.6.7 Electrolysis

Acceptable with precautions. Electrolysis permanently removes hair by inserting an

electrified needle (AC or DC) into the hair follicle. Electrolysis introduces electrical current
into the body, which can cause oversensing. Patients should consult with their clinicians to
determine if their cardiac condition allows them to undergo electrolysis.

To mitigate the effects of EMI during electrolysis, consider programming asynchronous
pacing.

2.6.8 Electrosurgery

Acceptable with precautions. Electrosurgery (including electrocautery, argon plasma

coagulation, electrosurgical cautery, advanced energy surgical technology, and hyfrecator)
uses an electric probe to control bleeding, cut tissue, or remove unwanted tissue.
Electrosurgery performed on patients with an implanted transcatheter pacemaker can result
in, but is not limited to, the following complications:

●

Potential pacing interruption during and up to 5 s immediately after exposure to
electrosurgery

●

Oversensing

●

Unintended tissue damage

●

Tachyarrhythmias

●

Device damage

●

Device malfunction

If electrosurgery is required, consider the following precautions:

●

Ensure that temporary pacing and defibrillation equipment is immediately available.

●

If possible, use a bipolar electrosurgery system or advanced energy surgical technology.
If a unipolar electrosurgery system is used, position the return electrode patch so that the
electrical current pathway passes no closer than 15 cm (6 in) from the device. Contact
Medtronic Technical Services for further guidance with unipolar electrosurgery.

●

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

●

Always monitor the patient during electrosurgery. If the ECG tracing is not clear due to
interference, manually monitor the patient’s rhythm (take pulse); alternatively, monitor by
some other means such as ear or finger pulse oximetry, Doppler pulse detection, or
arterial pressure display.

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2.6.9 External defibrillation and cardioversion

Acceptable with precautions. 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 transcatheter pacemakers are designed to withstand exposure to external
defibrillation and cardioversion. While damage to an implanted transcatheter pacemaker
from an external shock is rare, the probability increases with increased energy levels. These
procedures can also temporarily or permanently elevate pacing thresholds or temporarily or
permanently damage the myocardium.

Follow these precautions when you deliver external defibrillation or cardioversion:

●

Use the lowest clinically appropriate energy.

●

Position the patches or paddles at least 15 cm (6 in) from the implanted transcatheter
pacemaker.

●

Use a Medtronic programmer or a Medtronic device manager to evaluate the implanted
transcatheter pacemaker if you deliver external defibrillation or cardioversion.

2.6.10 Hearing aids

This section describes 2 types of hearing aids that can be used by patients with transcatheter
pacemakers.

Hearing aids and cochlear implants, in ear or hardwired

Acceptable. – Hearing aids or cochlear implants worn in the ear or hardwired to an

acoustical detector have no potential for EMI with an implanted transcatheter pacemaker.

Hearing aids with transmitting loop antenna

Acceptable with precautions. – A hearing aid with a transmitting loop antenna, worn

around the neck, radiates a magnetic field that is coupled with the T-coil in the earpiece.
Advise patients to keep the loop antenna at least 15 cm (6 in) from an implanted
transcatheter pacemaker.

If the loop antenna is closer than 15 cm (6 in) to a transcatheter pacemaker, there is potential
for pacing inhibition.

Advise patients to reposition the loop antenna to the shoulder opposite the implant site. If that
is not possible, advise patients to use an alternative transmitting antenna that can be worn
at least 15 cm (6 in) from the implanted device.

Note: This precaution also applies to transmitting loop antennae attached to audio
equipment.

Note: Bluetooth hearing aids without a transmitting loop are acceptable.

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2.6.11 Hyperbaric therapy (including hyperbaric oxygen therapy, or HBOT

Acceptable with precautions. Hyperbaric therapy is the medical use of air or 100%

oxygen at a higher pressure than atmospheric pressure. Hyperbaric therapy treats several
conditions, including decompression sickness, carbon monoxide poisoning, serious
infections, and persistent wounds. Hyperbaric therapies with pressures exceeding 4.0 ATA,
approximately 30 m (100 ft) of seawater, can affect the function of or damage an implanted
transcatheter pacemaker. To avoid or mitigate risks to an implanted transcatheter
pacemaker, do not expose patients to pressures exceeding 4.0 ATA.

2.6.12 Lithotripsy

Acceptable with precautions. Lithotripsy uses mechanical shock waves to break up

kidney stones or gallbladder stones. Lithotripsy can damage an implanted transcatheter
pacemaker if it is at the focal point of the lithotripter beam. Keep the focal point of the
lithotripter beam at least 2.5 cm (1 in) away from the implanted transcatheter pacemaker.

2.6.13 Magnetic resonance imaging (MRI)

A Medtronic Micra AV implanted transcatheter pacemaker is MR Conditional.

Use any of the following resources to confirm that the Medtronic Micra AV transcatheter
pacemaker is MR Conditional:

●

See the Medtronic MR Conditional Product Search for Cardiac Devices at
www.medtronic.com/mrc.

●

See the Medtronic MRI Resource Library at
http://manuals.medtronic.com/manuals/mri/region.

●

If you are in the USA, you can call [phone] for MRI technical consultation.

●

If you are outside of the USA, you can contact a Medtronic representative for MRI
technical consultation.

Patients with an implanted Medtronic Micra AV transcatheter pacemaker can undergo an
MRI scan under specified conditions. For details, refer to the Medtronic Micra AV MRI
technical manual, or contact the listed Medtronic resources.

2.6.14 Stereotaxis

Acceptable with precautions. Stereotaxis allows clinicians to steer catheter-based

diagnostic and therapeutic devices throughout the body by using magnetic navigation.
During a stereotaxis procedure, the magnetic field can cause interference to the device. The
implanted transcatheter pacemaker resumes normal programmed operation after the
stereotaxis procedure.

Clinicians should consult with cardiologists to determine if a stereotaxis procedure is safe for
their patients with an implanted transcatheter pacemaker.

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