Medtronic 5086MRI45 Technical Manual

CAPSUREFIX MRI™ SURESCAN™ 5086MRI

Steroid-eluting, bipolar, implantable, screw-in, ventricular/atrial, transvenous lead

Technical 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.

CapSureFix, CapSureFix MRI, Medtronic, Quick Twist, SureScan

Contents

1 Description 3
2 Drug component description 3
3 Indications 4
4 Contraindications 4
5 Warnings and precautions 4
6 Potential adverse events 5
7 Drug information 6
8 Implant procedure 7

9 Device description 12
10 Medtronic warranty 13
11 Service 13

1 Description

The Medtronic CapSureFix MRI SureScan Model 5086MRI
steroid-eluting, bipolar, implantable, screw-in, ventricular/atrial,
transvenous lead is designed for pacing and sensing applications
in either the atrium or ventricle. The lead has been designed for
use in the MRI environment when used with a Medtronic
MRI SureScan IPG. The platinum alloy tip and ring electrodes
feature a high-active surface area of titanium nitride
microstructure. This electrode configuration contributes to low
polarization.

The lead has a helical tip electrode made of platinum alloy that can
be actively fixed in the endocardium. The helix electrode can be
extended or retracted by rotating the lead connector pin with either
the Quick Twist tool attached to the lead or with the white fixation
tool. An active fixation lead is particularly beneficial for patients
who have smooth or hypertrophic hearts where lead
dislodgement may be a potential problem. The lead also has a
second, larger electrode proximal to the helical tip electrode and
an IS-1 Bipolar (BI) connector1 with one terminal pin. It features
MP35N nickel alloy conductors and silicone rubber insulation.
The outer insulation of the lead has been treated to facilitate ease
of implant.

The distal tip contains a nominal dosage of 680 µg of
dexamethasone acetate. Upon exposure to body fluids, the
steroid elutes from the lead tip. The steroid is known to suppress
the inflammatory response that is believed to cause threshold
rises typically associated with implanted pacing electrodes.

The Medtronic SureScan pacing system includes a Medtronic
SureScan device connected to Medtronic SureScan leads.
Labeling for SureScan pacing system components displays the
SureScan symbol and the MR Conditional symbol.

SureScan logo

MR Conditional symbol. The Medtronic MRI SureScan pacing
system is MR Conditional and, as such, is designed to allow
implanted patients the ability to undergo an MRI scan under the
specified MRI conditions for use.

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

refer to the SureScan pacing system technical manual for
important information about procedures and MRI-specific
warnings and precautions.

1.1 Package contents

Leads and accessories are supplied sterile. Each package
contains the following items:

●

1 lead with radiopaque anchoring sleeve, stylet, and Quick
Twist tool

●

1 white fixation tool

●

1 vein lifter

●

extra stylets

●

product documentation

1.2 Accessory descriptions

Anchoring sleeve – An anchoring sleeve secures the lead to

prevent it from moving and protects the lead insulation and
conductors from damage caused by tight sutures.

White fixation tool – The white fixation tool facilitates connector
pin rotation.

Quick Twist tool – The Quick Twist tool facilitates both connector
pin rotation and stylet insertion into the lead. This tool comes
attached to the lead.

Stylet – A stylet provides additional stiffness and controlled
flexibility for maneuvering the lead into position. Each stylet knob
is labeled with the stylet diameter and length.

Vein lifter – A vein lifter facilitates lead insertion into a vein.

2 Drug component description

The active ingredient in the Model 5086MRI lead is
dexamethasone acetate. Dexamethasone acetate is
9-Fluoro-11β,
17,21-trihydroxy-16α-methylpregna-1,4-diene-3,20-dione
21-acetate. Dexamethasone acetate has a molecular formula of
C24H31FO6 and a molecular weight of 434.50. The MCRD
(Monolithic controlled release device) excipient is silicone. See
Figure 1 for the structural formula.

1

IS-1 BI refers to an International Connector Standard (ISO 5841-3) whereby pulse generators and leads so designated are assured of a basic mechanical fit.

3

Figure 1.

The target dosage of dexamethasone acetate is 680 µg per lead.

3 Indications

The Medtronic MRI SureScan lead is indicated for use as a
system consisting of a Medtronic MRI SureScan IPG
implanted with SureScan leads. A complete system is
required for use in the MRI environmentThis lead has

application where implantable dual chamber MR Conditional
pacing systems are indicated.

4 Contraindications

●

Use of ventricular transvenous leads is contraindicated in
patients with tricuspid valvular disease.

●

Use of ventricular transvenous leads is contraindicated in
patients with mechanical tricuspid heart valves.

●

Use of steroid-eluting transvenous leads is contraindicated in
patients for whom a single dose of 680 µg dexamethasone
acetate may be contraindicated.

5 Warnings and precautions

Before performing an MRI scan, refer to the SureScan
pacing system technical manual for MRI-specific warnings
and precautions.
Note: Medical procedure warnings and precautions that pertain to

the Medtronic implanted system are provided in the manual that is
packaged with the device or on the Medtronic Manual Library
website (www.medtronic.com/manuals).

Line-powered and battery-powered equipment – An
implanted lead forms a direct current path to the myocardium.
During lead implant and testing, use only battery-powered
equipment or line-powered equipment specifically designed for
this purpose to protect against fibrillation that may be caused by
alternating currents. Line-powered equipment used in the vicinity
of the patient must be properly grounded. Lead connector pins
must be insulated from any leakage currents that may arise from
line-powered equipment.

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.

Magnetic resonance imaging (MRI) – An MRI is a type of
medical imaging that uses magnetic fields to create an internal
view of the body. If certain criteria are met and the warnings and
precautions provided by Medtronic are followed, patients with an
MR Conditional device and lead system are able to undergo an
MRI scan; for details, refer to the MRI Technical Manual that
Medtronic provides for the MR Conditional device.

Vessel and tissue damage – Use care when positioning the
lead. Avoid known infarcted or thin ventricular wall areas to
minimize the occurrence of perforation and dissection.

Single use – The lead and accessories are for single use only.

Inspecting the sterile package – Inspect the sterile package

with care before opening it.

●

If the seal or package is damaged, contact a Medtronic
representative.

●

Store 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 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.

●

Do not use the product after its expiration date.

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

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 lead. For a list of potential adverse effects, refer
to the Physicians’ Desk Reference.

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

●

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

●

Do not wipe or immerse the electrode in fluid, except blood, at
the time of implant.

Handling a screw-in lead – Handle the lead with care at all times.

●

Do not implant the lead if it is damaged. Return the lead to a
Medtronic representative.

●

Protect the lead from materials that shed small particles such
as lint and dust. Lead insulators attract these particles.

4

●

Handle the lead with sterile surgical gloves that have been
rinsed in sterile water or a comparable substance.

●

Do not severely bend, kink, or stretch the lead.

●

Do not immerse the lead in mineral oil, silicone oil, or any other
liquid, except blood, at the time of implant.

●

Do not use surgical instruments to grasp the lead or connector
pin.

●

Do not force the lead if resistance is encountered during lead
passage.

●

Exercise the helix electrode before implanting the lead. On
initial extension, more rotations may be required to extend and
retract the helix electrode, or the helix electrode may extend
suddenly when torque is built up.
Note: The estimated number of rotations (using the fixation
tool) needed to initially extend or retract the helix electrode is
stated in Table 3.

●

Ensure helix is retracted prior to implant.

●

The number of turns required to extend and subsequently
retract the helix may be different. Verify helix electrode
extension and retraction using fluoroscopy during implant
(Figure 8). Overrotation of the connector pin may result in
fracture or distortion of the inner conductor or retraction of the
helix electrode out of its channel.

Handling the stylet – Handle the stylet with care at all times.

●

Curve the stylet before inserting it into the lead to achieve a
curvature at the lead’s distal end. Do not use a sharp object to
impart a curve to the distal end of the stylet.

●

Do not use excessive force or surgical instruments when
inserting the stylet into the lead.

●

Avoid overbending or kinking the stylet.

●

Use a new stylet when blood or other fluids accumulate on the
stylet. Accumulated blood or other fluids may damage the
lead or cause difficulty in passing the stylet into the lead.

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

Concurrent devices – Output pulses, especially from unipolar
devices, may adversely affect device sensing capabilities. If a
patient requires a separate stimulation device, either permanent
or temporary, allow enough space between the leads of the
separate systems to avoid interference in the sensing capabilities
of the devices. Previously implanted pulse generators and
implantable cardioverter defibrillators should generally be
explanted.

Chronic lead removal and the SureScan pacing system –

When implanting a SureScan pacing system, consider the risks
associated with removing previously implanted leads before
doing so. Abandoned leads or previously implanted
non-SureScan labeled leads compromise the ability to safely
scan the SureScan pacing system during MRI scans.

Chronic repositioning or removal of a screw-in lead –

Proceed with extreme caution if a lead must be removed or
repositioned. Chronic repositioning or removal of screw-in
transvenous leads may not be possible because of blood or

fibrotic tissue development into the helix mechanism on the lead.
In most clinical situations, it is preferable to abandon unused leads
in place. Return all removed leads, unused leads, or lead sections
to Medtronic for analysis.

Note: If a helix electrode does not disengage from the
endocardium by rotating the connector pin, rotating the lead body
counterclockwise may withdraw the helix electrode and decrease
the possibility of damage to cardiovascular structures during
removal.

●

Lead removal may result in avulsion of the endocardium,
valve, or vein.

●

Lead junctions may separate, leaving the lead tip and bare
wire in the heart or vein.

●

Chronic repositioning of a lead may adversely affect the
low-threshold performance of a steroid lead.

●

An abandoned lead should be capped so that the lead does
not transmit electrical signals.

●

Severed leads should have the remaining lead end sealed
and the lead body sutured to adjacent tissue.

Connector compatibility – Although the lead conforms to the
IS-1 International Connector Standard, do not attempt to use the
lead with any device other than a commercially available
implantable pacing system with which it has been tested and
demonstrated to be safe and effective. The potential adverse
consequences of using such a combination may include, but are
not limited to, undersensing cardiac activity and failure to deliver
necessary therapy.

6 Potential adverse events

The potential complications (listed in alphabetical order) related
to the use of transvenous leads include, but are not limited to, the
following patient-related conditions that can occur when the lead
is being inserted or repositioned:

●

cardiac perforation

●

cardiac tamponade

●

fibrillation and other arrhythmias

●

heart wall rupture

●

infection

●

muscle or nerve stimulation

●

myocardial irritability

●

pericardial rub

●

pericarditis

●

pneumothorax

●

thrombotic and air embolism

●

thrombosis

●

valve damage (particularly in fragile hearts)

5

Other potential complications related to the screw-in lead and the
programmed parameters include, but are not limited to, the
complications listed in the following table. Symptoms of the
following potential complications include loss of capture or
intermittent or continuous loss of capture or sensing2:

Complication

Lead dislodgement Reposition the lead.

Lead conductor or helix electrode
fracture or insulation failure

Threshold elevation or exit blockaAdjust the implantable device out-

a

Evidence indicates that there is a higher frequency of exit block in the
ventricle when using a screw-in lead. This should be considered when
selecting a screw-in lead for use in the ventricle.

Corrective action to be consid­ered

Replace the lead. In some cases
with a bipolar lead, the implantable
device may be programmed to a
unipolar configuration or the lead
may be unipolarized.

put. Replace or reposition the lead.

Potential acute or chronic complications associated with screw-in
lead placement that may require lead replacement to correct
include, but are not limited to, the following:

Implant technique Potential complication

Forcing the lead through the intro­ducer

Use of too medial of an approach
with venous introducer resulting in
clavicle and first rib binding

Puncturing the periosteum and/or
tendon when using subclavian
introducer approach

Advancing the lead into the venous
insertion site and/or through the
veins without the stylet fully inser­ted

Bending the lead or manually
pinching the lead body during
extension or retraction of the helix
electrode

Screw electrode damage, insula­tion damage

Conductor coil fracture, insulation
damage, helix engagement issues

Conductor coil fracture, insulation
damage

Tip distortion, insulation perfora­tion

Delayed torque transfer

In addition, prolonged implant procedures or repositioning the
lead multiple times may allow blood or body fluids to build up on
the helix mechanism. This may result in an increased number of
rotations needed to extend or retract the helix electrode, which
may damage the lead.

7 Drug information

7.1 Mechanism of action

Steroid suppresses the inflammatory response that is believed to
cause threshold rises typically associated with implanted pacing
electrodes. Dexamethasone acetate is a synthetic steroid of the

glucocorticoid family. Glucocorticoids have potent
anti-inflammatory actions via direct and indirect effects on major
inflammatory cells. Glucocorticosteroids bind to a cytoplasmic
glucocorticoid receptor as well as a membrane-bound receptor.
Binding to the cytoplasmic receptor leads to receptor activation
and translocation to the nucleus. The receptor interacts with
specific DNA sequences within the regulatory regions of affected
genes. Thus, glucocorticoids inhibit the production of multiple cell
factors that are critical in generating the inflammatory response.

7.2 Pharmacokinetics and metabolism

Pharmacokinetics – The pharmacokinetics (local drug levels

and systemic levels) of dexamethasone acetate and its
metabolites following implant were not evaluated in human clinical
trials. When delivered intra-muscularly, the lipid-soluble
dexamethasone acetate is slowly absorbed throughout the tissue.

Metabolism – The conversion of dexamethasone acetate to
dexamethasone occurs within hours. The dexamethasone
alcohol (dexamethasone) is the active glucocorticoid used in this
Medtronic lead. Steroid is applied via MCRD (Monolithic
controlled release device) and eluted to the tissue interface where
it will be used. The form of the steroid, whether it is a prodrug or the
pharmacologically active dexamethasone, is irrelevant, as the
steroid is directly present at the injury site to treat the
inflammation. Dexamethasone acetate is hydrolyzed into
dexamethasone, which is readily absorbed by the surrounding
tissue and body fluids. Glucocorticoids, when given systemically,
are eliminated primarily by renal excretion of inactive metabolites.

7.3 Mutagenesis, carcinogenicity, and reproductive toxicity

Mutagenesis, carcinogenicity and reproductive toxicity –

The mutagenesis, carcinogenicity, and reproductive toxicity or the
Model 5086MRI lead have not been evaluated. However, the
mutagenesis, carcinogenicity, and reproductive toxicity of
dexamethasone acetate has been evaluated previously.

Carcinogenesis, mutagenesis, and impairment of fertility –

No adequate studies have been conducted in animals to
determine whether corticosteroids have a potential for
carcinogenesis (tumor initiation or promotion). Dexamethasone
was genotoxic in assays for clastogenicity (including sister
chromatid exchange in human lymphocytes) but not in an assay
for mutagenicity in salmonella (Ames test).

Adrenocorticoids have been reported to increase or decrease the
number and mobility of spermatozoa in some patients.

7.4 Pregnancy

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

2

Transient loss of capture or sensing may occur for a short time following implant until lead stabilization takes place. If stabilization does not occur, lead dislodgement
may be suspected.

6

adrenocorticoids increase the incidence of cleft palate, placental

1

insufficiency, and spontaneous abortions, and can decrease the
intrauterine growth rate.

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. Because of the potential for serious
adverse reactions in nursing infants from corticosteroids, a
decision should be made whether to discontinue nursing or to use
a non-steroidal lead, taking into account the importance of the
lead and the drug to the mother.

7.5 Lactation

Corticosteroids are secreted into human milk and there is a
potential for serious adverse reactions. A decision should be
made whether to nurse or to discontinue the drug, taking into
account the importance of the drug to the mother. These potential
risks of corticosteroids should also be considered along with any
other steroidal therapy being received by the patient.

8 Implant procedure

Warning: When implanting a SureScan pacing system, consider

the risks associated with removing previously implanted leads
before doing so. Abandoned leads or previously implanted
non-SureScan labeled leads compromise the ability to safely
scan the SureScan pacing system during MRI scans.

Proper surgical procedures and sterile techniques are the
responsibility of the medical professional. Some implant
techniques vary according to physician preference and the
patient’s anatomy or physical condition.

8.1 Verifying the mechanical functioning of the helix electrode

Note: The package includes 2 tools, the Quick Twist tool attached

to the lead and the white fixation tool. Either tool may be used to
verify the mechanical functioning of the helix electrode. The
choice of tool is left to the discretion of the physician.

Before implant, verify the mechanical functioning of the helix
electrode using the following steps:

1. Attach either the Quick Twist tool or the white fixation tool to
the lead. Ensure that the stylet is inserted into the lead and
proceed as indicated, according to the tool being used.

a. Quick Twist tool: Push the Quick Twist tool onto the

connector pin (Figure 2).

Figure 2.

b. White fixation tool: Press both legs of the white fixation

tool together and place the most distal hole on the
connector pin (Figure 3).

Figure 3.

1 The most distal hole of the white fixation tool.

2. Keep the lead body and the IS-1 connector sleeve as straight
as possible (Figure 3). Ensure that the stylet is fully inserted,
then rotate the selected fixation tool clockwise until the helix
electrode is fully extended (Figure 4 or Figure 5). When the
helix electrode is fully extended, approximately 1.5 to 2 helix
coils are exposed.

Figure 4.

7

Figure 5.

1

Caution: Do not severely bend the IS–1 connector sleeve or

the lead body while extending the helix electrode.
Caution: Overrotating the connector pin after the helix
electrode is fully extended may damage the lead.
The number of rotations required to extend the helix
electrode increases proportionately with the length of the
lead. Additional curvatures made to the stylet may increase
the number of rotations needed to extend or retract the helix
electrode. Refer to Table 3 for the estimated number of
rotations required to extend or retract the helix electrode.
Note: The number of rotations required to extend the helix
electrode is variable depending on the lead path.
During the initial helix electrode extension, the helix
electrode may extend suddenly due to accumulated torque
in the lead, or the helix electrode may require additional
rotations for extension.

3. Disconnect the selected fixation tool from the connector pin
and release the proximal end of the lead body. Allow several
seconds for relief of the residual torque in the lead.

4. After allowing for relief of the residual torque, reattach the
selected fixation tool and rotate it counterclockwise until the
helix electrode tip is retracted into the sheath.

8.2 Inserting the lead

Caution: Use care when handling the lead during insertion.

●

Do not severely bend, kink, or stretch the lead.

●

Do not use surgical instruments to grasp the lead or
connector pins.

Insert the lead using the following techniques:

1. Select a site for lead insertion. The lead may be inserted by
venotomy through several different venous routes, including
the right or left cephalic vein or the external or internal jugular
vein. Use the cephalic vein whenever possible to avoid lead
damage in the first rib or clavicular (thoracic inlet) space.

Cautions:

●

Certain anatomical abnormalities, such as thoracic
outlet syndrome, may also precipitate pinching and
subsequent fracture of the lead.

●

When using a subclavian approach, avoid techniques
that may damage the lead.

●

Place the insertion site as far lateral as possible to avoid
clamping the lead body between the clavicle and the first
rib (Figure 6).

Figure 6.

1 Suggested entry site

●

Do not force the lead if significant resistance is
encountered during lead passage.

●

Do not use techniques such as adjusting the patient’s
posture to facilitate lead passage. If resistance is
encountered, it is recommended that an alternate
venous entry site be used.

2. Insert the tapered end of a vein lifter into the incised vein and
gently push the lead tip underneath and into the vein
(Figure 7).
Note: A percutaneous lead introducer (PLI) kit may be used
to facilitate insertion. If a slittable introducer is used, it should
be at least 2.6 mm (8 French). Refer to the technical manual
packaged with an appropriate percutaneous lead introducer
for further instructions.

Figure 7.

3. Advance the lead into the right atrium using a straight stylet to
facilitate movement through the veins.

8.3 Positioning a screw-in ventricular lead

Caution: Use care when handling the lead during positioning:

●

Do not severely bend, kink, or stretch the lead.

●

Do not use surgical instruments to grasp the lead or connector
pin.

1. Insert the tapered end of a vein lifter into the incised vein and
gently push the lead tip underneath and into the vein. A vein
lifter facilitates lead insertion.

2. Advance the lead into the right atrium using a straight stylet to
facilitate movement through the veins.

8

3. Advance the lead through the tricuspid valve. Replacing the
straight stylet with a gently curved stylet may add control in
maneuvering the lead through the tricuspid valve. Then,
advance the lead directly through the tricuspid valve, or
project the lead tip against the lateral atrial wall and retract
the curved portion of the lead body through the tricuspid
valve until the lead tip enters the ventricle.

4. Position the lead in the ventricle using the following
techniques. Accurate positioning of the helix electrode is
essential for stable pacing.
Caution: If there is reason to believe the patient has an
unusually thin wall at the apex of the right ventricle, you may
want to consider another site for placement of the lead.
Caution: If placing the lead in or near the right ventricular
apex, use caution if passing the distal end of the lead directly
from the valve to the apex. This technique may result in
excessive tip pressure.
Caution: If an awake patient feels a twinge of pain, this may
be an early sign of perforation.
Using one of the following techniques may help minimize
transmission of pressure directly toward the tip of the lead:

●

Partially withdraw the stylet so that the stylet tip is
proximal to the electrode ring while positioning the lead,
to minimize tip stiffness. The stylet can then be gently
advanced to the tip of the lead before securing the
electrode in the endocardium.

●

A curved stylet may be used during positioning to
minimize direct pressure on the apex.

●

Using a curved stylet, or partially withdrawing the stylet
to allow the lead to be carried by blood flow, the lead may
be curved up toward the outflow tract and then allowed to
fall gently into position near the apex by pulling back on

the lead body.
Use fluoroscopy (lateral position) to ensure that the tip is not
in a retrograde position or is not lodged in the coronary sinus.

5. After placing the lead in a satisfactory position, extend the
helix electrode by following the procedure in Section 8.5.

8.4 Positioning a screw-in atrial lead

Caution: Use care when handling the lead during positioning:

●

Do not severely bend, kink, or stretch the lead.

●

Do not use surgical instruments to grasp the lead or connector
pin.

The following procedure is suggested for atrial placement of the
lead:

1. Insert the tapered end of a vein lifter into the incised vein and
gently push the lead tip underneath and into the vein. A vein
lifter facilitates lead insertion.

2. Advance the lead into the right atrium using a straight stylet to
facilitate movement through the veins. After the lead tip is
passed into the atrium, replace the straight stylet with a
gently curved stylet or one of the J-shaped stylets supplied
with the lead.

3. Direct the lead tip into an appropriate position. Accurate
positioning of the helix electrode is essential for stable
pacing and sensing.
Generally, a satisfactory position has the lead tip situated
against the atrial endocardium in or near the apex of the
appendage. As viewed on the fluoroscope (A-P view), the
lead tip points medially and forward toward the left atrium. A
successful position is usually achieved with an anterior,
medial, or lateral tip location.

Caution: If an awake patient feels a twinge of pain, this may be an
early sign of perforation.

After placing the lead tip in a satisfactory position, extend the helix
electrode by following the procedure in Section 8.5.

8.5 Securing the helix electrode into the endocardium

Note: The package includes 2 tools, the Quick Twist tool attached

to the lead and the white fixation tool. Either tool may be used to
secure the helix electrode into the endocardium. The choice of
tool is left to the discretion of the physician.

Secure the helix electrode using the following techniques:

1. Attach either the Quick Twist tool or the white fixation tool to
the lead. Ensure that the stylet is inserted into the lead and
proceed as indicated, according to the tool being used.

a. Quick Twist tool: Push the Quick Twist tool onto the

connector pin (Figure 2).

b. White fixation tool: Press both legs of the white fixation

tool together and place the most distal hole on the
connector pin (Figure 3).

2. Press the lead tip against the endocardium using the
appropriate technique:

a. Ventricular placement: Press the lead tip against the

endocardium by gently pushing the stylet and lead at the
vein entry site.

b. Atrial placement: With the lead tip advanced into the

atrium and a J-shaped or gently curved stylet in the lead,
press the lead tip against the endocardium by gently
pulling the stylet and the lead at the vein entry site.

3. Rotate the selected fixation tool clockwise until the helix
electrode is fully extended.
Caution: Do not severely bend the IS-1 connector sleeve or
the lead body while extending the helix electrode.

4. Use fluoroscopy to verify helix electrode extension. This is
the only reliable method to confirm extension. Extension of
the space between the indicator ring (A) and the drive
mechanism (B) implies complete exposure of the helix
electrode (Figure 8). The top view illustrates no gap between
the indicator ring and the drive mechanism (retracted) and
the bottom view illustrates a gap (extended).

9

Cautions:

Retracted

Extended

●

The estimated number of rotations required to fully
extend or retract the helix electrode is variable. Refer to
Table 3, for the estimated number of rotations.

●

Prolonged implant procedures or repositioning the lead
multiple times may allow blood or body fluids to build up
on the helix mechanism. This may result in an increased
number of rotations required to extend or retract the
helix electrode, which may damage the lead.

Figure 8.

5. Remove the selected fixation tool from the IS-1 connector pin
and release the proximal end of the lead body. Allow several
seconds for relief of the residual torque in the lead.

6. Partially withdraw the stylet.

7. Verify that the lead is affixed.

a. For a lead placed in the ventricle: Gently pull back on

the lead and check for resistance to verify affixation. A
properly affixed helix electrode will remain in position. If
the helix electrode is not properly affixed, the lead tip may
become loose in the right ventricle.

b. For a lead placed in the atrial appendage: After the

lead tip is fixed, allow lead slack to build up in the atrium.
Lead slack helps prevent tip dislodgement. Enough slack
is assumed present if, under fluoroscopy, the lead
assumes an “L” shape during deep inspiration. Avoid
excessive slack buildup that may cause the loop of the
lead to drop near the tricuspid valve.

8. If repositioning is required, reattach the selected fixation tool
and rotate counterclockwise until the helix electrode is
retracted. Use fluoroscopy to verify withdrawal of the helix
electrode before attempting to reposition (Figure 8).
Caution: Do not rotate the selected fixation tool more than
the number of rotations required to fully retract the helix
electrode.

9. After final positioning, remove the stylet and the Quick Twist
tool completely. When removing the Quick Twist tool, grip the
lead firmly just below the connector pin to help prevent lead
dislodgement.

10. Obtain final electrical measurements.

8.6 Taking electrical measurements

Take electrical measurements:

1. Attach the clip of a surgical cable to the notch on the stylet
guide (Figure 9).

Figure 9.

Note: A unipolar lead requires the use of an indifferent

electrode.

2. Use an implant support instrument to obtain electrical
measurements. Medtronic recommends using a pacing
system analyzer. For information on the use of the implant
support instrument, see the product literature for that device.
Satisfactory lead placement is indicated by low stimulation
thresholds and adequate sensing of intracardiac signal
amplitudes. Refer to Table 1 for recommended stimulation
threshold and sensing amplitude measurements at implant.

●

A low stimulation threshold provides for a desirable
safety margin, allowing for a possible rise in thresholds
that may occur within 2 months following implant.

●

Adequate sensing amplitudes ensure that the lead is
properly sensing intrinsic cardiac signals. Minimum
signal requirements depend on the device’s sensitivity
capabilities. Acceptable acute signal amplitudes for the
lead must be greater than the minimum device sensing
capabilities, including an adequate safety margin to
account for lead maturity.

Table 1. Recommended measurements at implant

Ventricle Atrium

Maximum acute stimulation thresholds

Minimum acute sensing amplitudes 5.0 mV 2.0 mV

a

At pulse duration setting of 0.5 ms.

a

1.0 V

3.0 mA

1.5 V

4.5 mA

3. If electrical measurements do not stabilize to acceptable
levels, repositioning the lead and repeating the testing
procedure may be necessary.
Note: Initial electrical measurements may deviate from the
recommendations because of acute cellular trauma. If such
a deviation occurs, wait 5 to 15 min and repeat the testing
procedure. Values may vary depending upon lead type,
device settings, cardiac tissue condition, and drug
interactions.

8.6.1 Checking diaphragmatic stimulation for screw-in leads

Diaphragmatic stimulation should also be checked by pacing at
10 V and observing on fluoroscopy whether the diaphragm
contracts with each paced stimulus. If diaphragmatic stimulation
occurs, reposition the lead.

10

8.6.2 Taking pacing impedance (or resistance)

1

measurements

Pacing impedance (or resistance) is used to assess device
function and lead integrity during routine device patient follow-up
sessions and to assist in troubleshooting suspected lead failures.
Additional troubleshooting procedures include ECG analysis,
visual inspection, measurement of thresholds, and electrogram
characteristics.

Pacing impedance values are affected by many factors including
lead position, electrode size, conductor design and integrity,
insulation integrity, and the patient’s electrolyte balance. Apparent
pacing impedance is also significantly affected by the
measurement technique. Comparison of pacing impedance
should be done using consistent methods of measurements and
equipment.

An impedance higher or lower than the typical values is not
necessarily a conclusive indication of a lead failure. Other causes
must be considered as well. Before reaching a conclusive
diagnosis, the full clinical picture must be considered. The full
clinical picture includes pacing artifact size and morphology
changes in 12-lead analog ECGs, muscle stimulation with bipolar
leads, sensing and/or capture problems, patient symptoms, and
device characteristics.

Recommendations for clinically monitoring and evaluating leads
in terms of impedance characteristics are listed below.

Consider the following recommendations for devices with
telemetry readout of impedance:

●

Routinely monitor and record impedance values at implant
and follow-up sessions using consistent output settings.
Note: Impedance values may be different at different
programmable output settings (for example, pulse width or
pulse amplitude) of the device or pacing system analyzer.

●

Establish a baseline chronic impedance value once the
impedance has stabilized, generally within 6 to 12 months
after implant.

●

Monitor for significant impedance changes and abnormal
values.

●

Where impedance abnormalities occur, closely monitor the
patient for indications of pacing and sensing problems. The
output settings used for measuring impedance should be the
same as those used for the original measurements.

●

For patients at high risk, such as implantable
device-dependent patients, consider further action such as
increased frequency of monitoring, provocative maneuvers,
and ambulatory ECG monitoring.

Consider the following recommendations for devices without
telemetry:

●

Record the impedance value at implant. Also record the
measurement device, its output settings, and the procedure
used.

●

At the time of device replacement, if pacing system
analyzer-measured impedance is abnormal, carefully

evaluate lead integrity (including thresholds and physical
appearance) and patient condition before electing to reuse
the lead.

●

Impedances below 250 Ω may result in excessive battery
current drain, which may seriously compromise device
longevity, regardless of lead integrity.

For more information on obtaining electrical measurements,
consult the product literature supplied with the testing device.

8.7 Anchoring the lead

Cautions:

●

Use care when anchoring the lead.

●

Use an anchoring sleeve with all leads.

●

Do not use absorbable sutures to anchor the lead.

●

Do not secure the sutures so tightly that they damage the vein,
lead, or anchoring sleeve.

●

Do not use the anchoring sleeve tabs for suturing (Figure 10).

●

Do not tie a suture directly to the lead body (Figure 11).

●

Do not dislodge the lead tip.

●

Do not attempt to remove or cut the anchoring sleeve.

●

Do not remove the tabs on anchoring sleeves. Tabs are
provided to minimize the possibility of the sleeve entering the
vein.

●

If a large diameter percutaneous lead introducer (PLI) sheath
is used, take extreme care to prevent passage of the
anchoring sleeve into the PLI lumen or the venous system.

Figure 10.

1 Anchoring sleeve tab

Figure 11.

With a triple groove anchoring sleeve, generally 2 or 3 of the
grooves may be used with the following procedure.

Note: The anchoring sleeves contain a radiopaque substance,
which allows visualization of the anchoring sleeve on a standard
x-ray and may aid in follow-up examinations.

Anchor the lead:

1. Position the anchoring sleeve close to the lead’s connector
pin to prevent inadvertent passage of the sleeve into the vein.

2. Insert the anchoring sleeve partially into the vein.

3. Use the most distal suture groove to secure the anchoring
sleeve to the vein.

11

4. Use the middle groove to secure the anchoring sleeve to the
fascia and lead (Figure 12):

a. Create a base by looping a suture through the fascia

underneath the middle groove and tying a knot.

b. Firmly wrap the suture around the middle groove and tie

a second knot.

Figure 12.

5. If anchoring with all 3 grooves, use the third and most
proximal groove to secure the anchoring sleeve to the lead
body (Figure 13).

Figure 13.

8.8 Connecting the lead

Caution: Always remove the stylet and stylet guide before

connecting the lead to the device. Failure to remove the stylet and
stylet guide may result in lead failure.

Connect the lead to the device:

1. Carefully and completely remove the stylet and stylet guide.
Note: When removing the stylet and stylet guide, firmly grip
the lead just below the connector pin to help prevent possible
lead dislodgement.

2. Obtain final electrical measurements.

3. Insert the lead connector into the connector block on the
device. For instructions on proper lead connections, see the
product documentation supplied with the device.

8.9 Placing the device and lead into the pocket

Cautions:

●

Use care when placing the device and lead into the pocket.

●

Ensure that the lead does not leave the device at an acute
angle.

●

Do not grip the lead or device with surgical instruments.

●

Do not coil the lead (Figure 14). Coiling the lead can twist the
lead body and may result in lead dislodgement.

Figure 14.

Caution: To prevent undesirable twisting of the lead body, wrap

the excess lead length loosely under the device and place both the
device and the lead into the subcutaneous pocket.

Place the device and lead into the pocket:

1. Rotate the device to loosely wrap the excess lead length
under the device (Figure 15).

Figure 15.

2. Insert the device and lead into the pocket.

3. Suture the pocket closed.

4. Monitor the patient’s electrocardiogram until the patient is
discharged. If a lead dislodges, it usually occurs during the
immediate postoperative period.

9 Device description

9.1 Specifications (nominal)

Table 2. Specifications (nominal)

Parameter Model 5086MRI

Type Bipolar

Chamber Atrium/Ventricle

Fixation Screw-in

Lengths 45, 52, 58 cm

Connector IS-1 BI

Materials Conductor: MP35N nickel alloy

Insulation: Treated silicone rubber

Connector pin: Stainless steel

Connector ring: Stainless steel

Electrode materi­als

Helix electrode: Titanium nitride coated plati-

num alloy

Ring electrode: Titanium nitride coated plati-

num alloy

12

Table 2. Specifications (nominal) (continued)

Parameter Model 5086MRI

Electrode surface
area

Tip to ring spacing 10 mm

Diameter Lead body: 2.3 mm

Lead introducer (recommended size)

Helix length (fully extended) 1.8 mm

Resistance Unipolar: 70.0 Ω (58 cm)

Steroid Type: Dexamethasone acetate

Nominal dosage of steroid 680 µg (target dose)

Steroid binder Silicone

Helix: 4.2 mm

Ring: 24 mm

without guide

wire:

with guide wire: 3.7 mm (11 French)

Bipolar: 105.0 Ω (58 cm)

2

2

2.7 mm (8 French)

Table 3. Estimated number of rotations required to extend or retract the helix electrode for initial placement

Lead length Straight stylet J-shaped stylet

45 cm 12 18

52 cm 13 20

58 cm 14 21

a

The number of rotations required to extend the helix electrode is variable
depending on the lead path. In addition, the number of turns required to
extend and subsequently retract the helix may be different. Verify
extension and retraction with fluoroscopy.

a

10 Medtronic warranty

For complete warranty information, see the accompanying
warranty document.

11 Service

Medtronic employs highly trained representatives and engineers
located throughout the world to serve you and, upon request, to
provide training to qualified hospital personnel in the use of
Medtronic products. Medtronic also maintains a professional staff
to provide technical consultation to product users. For more
information, contact your local Medtronic representative, or call or
write Medtronic at the appropriate telephone number or address
listed on the back cover.

13

Medtronic, Inc.

*M955299A001*

710 Medtronic Parkway
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]

Europe/Middle East/Africa

Medtronic International Trading Sàrl
Route du Molliau 31
Case Postale 84
CH-1131 Tolochenaz
Switzerland
[phone]

Technical manuals

www.medtronic.com/manuals

© 2015 Medtronic, Inc.
M955299A001 A
2015-09-23