Medtronic 407658 Technical Manual

CapSureFix Novus MRI™ SureScan™ 4076

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 Novus MRI, Medtronic, SureScan

Contents

1 Description 3
2 Drug component description 4
3 Indications 4
4 Contraindications 4
5 Warnings and precautions 4
6 Drug information 6
7 Adverse events 6
8 Clinical trials 7

9 Directions for use 9
10 Specifications 15
11 Medtronic warranty 16
12 Service 16

1 Description

The Medtronic CapSureFix Novus MRI SureScan 4076 steroid
eluting, bipolar, implantable, screw-in, ventricular/atrial,
transvenous lead is designed for pacing and sensing applications
in either the atrium or ventricle. 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 been tested for use in the Magnetic
Resonance Imaging (MRI) environment. The following lead
lengths are MR conditional: 35 cm to 85 cm. Other lead lengths
are not MR conditional.

The helical tip electrode on the lead can be actively fixed in the
endocardium. The helix electrode can be extended or retracted by
rotating the lead connector pin with a fixation tool. An active
fixation lead is particularly beneficial for patients who have smooth
or hypertrophic hearts where lead dislodgment may be a potential
problem. The lead also has a second, larger electrode proximal to
the helical tip electrode and an IS-11 Bipolar (BI) connector with 1
terminal pin. The lead features MP35N nickel alloy conductors, an
outer insulation of 55D polyurethane, and an inner insulation of
silicone rubber.

The distal tip of the lead contains a target 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.

1.1 Medtronic SureScan system

A complete SureScan pacing system is required for use in
the MR environment. A complete SureScan system includes
a Medtronic SureScan device with the appropriate number
of Medtronic SureScan leads. Any other combination may

result in a hazard to the patient during an MRI scan.

The Model 4076 lead is part of the Medtronic SureScan system.
The SureScan system includes a Medtronic SureScan device
connected to Medtronic SureScan leads. Labeling for SureScan
system components displays the SureScan logo and the MR
Conditional symbol. To verify that components are part of a
SureScan system, visit http://www.mrisurescan.com.

SureScan logo

MR Conditional symbol. The Medtronic SureScan sys­tem is MR Conditional and is designed to allow implan­ted patients 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 MRI technical manual for important
information about procedures and MRI-specific warnings
and precautions.

1.2 Contents of package

The lead and accessories are supplied sterile. Each package
contains:

●

1 lead with 1 radiopaque anchoring sleeve, stylet, and stylet
guide

●

1 vein lifter

●

2 fixation tools

●

extra stylets

●

product documentation

1.3 Accessory descriptions

Dispose of all single-use accessories according to local
environmental requirements.

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.

Fixation tool – A fixation tool facilitates connector pin rotation.

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 corresponding lead length.

1

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

3

Stylet guide – A stylet guide facilitates stylet insertion into the
lead.

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

2 Drug component description

The active ingredient in the Model 4076 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.

Figure 1.

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

3 Indications

The Model 4076 lead is designed to be used with a compatible
implantable pulse generator as part of a chronic cardiac pacing
system. The lead has application where implantable atrial or
ventricular, single chamber or dual chamber pacing systems are
indicated.

4 Contraindications

Before performing an MRI scan, refer to the SureScan MRI
technical manual for MRI-specific contraindications.

●

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

●

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

●

Use of a steroid eluting lead is contraindicated in patients for
whom a single dose of 1.0 mg of dexamethasone acetate may
be contraindicated.

5 Warnings and precautions

A complete SureScan system is required for use in the MRI
environment. Before performing an MRI scan, refer to the

SureScan 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).

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 SureScan MRI technical manual
that Medtronic provides for an MR Conditional device.

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.

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

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.

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.

Inspecting the sterile package – Inspect the sterile package
with care before opening it.

●

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

4

●

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.

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.

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 listing of potential adverse effects,
refer to the dexamethasone acetate manufacturer prescribing
information or the Physicians’ Desk Reference.

Steroid elution and exit block – Although the addition of steroid
to passive fixation leads has been shown to reduce pacing
thresholds in patients with a history of exit block, the frequency of
redevelopment of exit block was not statistically different between
the steroid eluting and the non-steroid eluting, active fixation,
screw-in leads in the Medtronic Model 4068 clinical trial.

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 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.

Before inserting the lead – Use an anchoring sleeve with all
leads. Ensure that the anchoring sleeve is positioned close to the
lead connector pin. This will prevent inadvertent passage of the
sleeve into the vein. If wiping the lead is necessary prior to
insertion, ensure that the anchoring sleeve remains in position.

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.

Handling a 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.

●

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.

●

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

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.

External defibrillation and cardioversion – External
defibrillation and cardioversion are therapies that deliver an
electrical shock to the heart to convert an abnormal heart rhythm
to a normal rhythm.

5

Medtronic cardiac devices are designed to withstand exposure to
external defibrillation and cardioversion. While damage to an
implanted system from an external shock is rare, the probability
increases with increased energy levels. These procedures may
also temporarily or permanently elevate pacing thresholds or
temporarily or permanently damage the myocardium. If external
defibrillation or cardioversion are required, consider the following
precautions:

●

Use the lowest clinically appropriate energy.

●

Position the patches or paddles no closer than 15 cm (6 in) to
the device.

●

Position the patches or paddles perpendicular to the device
and lead system.

●

If an external defibrillation or cardioversion is delivered within
15 cm (6 in) of the device, use a Medtronic programmer to
evaluate the device and lead system.

6 Drug information

6.1 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.

6.2 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.

6.3 Mutagenesis, carcinogenicity, and reproductive toxicity

Mutagenesis, carcinogenicity, and reproductive toxicity –

The mutagenesis, carcinogenicity, and reproductive toxicity of the

CapSureFix Novus 4076 lead have not been evaluated. However,
the mutagenesis, carcinogenicity, and reproductive toxicity of
dexamethasone acetate have 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.

6.4 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
adrenocorticoids increase the incidence of cleft palate, placental
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.

6.5 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.

7 Adverse events

The potential adverse events 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 and/or
repositioned:

●

cardiac perforation

●

cardiac tamponade

●

fibrillation and other arrhythmias

●

heart wall rupture

●

infection

●

muscle or nerve stimulation

●

myocardial irritability

●

pericardial rub

●

pericarditis

6