Dexamethasone acetate steroid eluting, quadripolar, ventricular lead with tined tip and RV/SVC defibrillation coil
electrodes
Technical Manual
Caution: Federal law (USA) restricts this device to sale by or on the order of a physician.
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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.
AccuRead, Medtronic, Sprint Quattro, Tensi-Lock
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Contents
1 Device description3
2 Drug component description3
3 Indications4
4 Contraindications4
5 Warnings and precautions4
6 Potential adverse events5
7 Clinical data6
8 Drug information6
9 Directions for use7
10 Specifications (nominal)11
11 Medtronic warranty12
12 Service12
13 Explanation of symbols on package labeling12
1 Device description
The Medtronic Sprint Quattro Model 6946M lead is a
steroid-eluting, quadripolar, tined tip, ventricular lead with right
ventricular (RV) and superior vena cava (SVC) defibrillation coil
electrodes. This lead is designed for pacing, sensing,
cardioversion, and defibrillation therapies.
The lead features tines, silicone insulation with overlay, parallel
conductors, tip and ring electrodes, and RV and SVC coils. The
lead also features Tensi-Lock1 and silicone-backfilled
defibrillation coils.
The DF4-LLHH2 four-pole HV inline connector on the lead
facilitates device connection during implant. The DF4 connector
pin has a color band indicator that may be used to visually confirm
proper connection to the device.
The RV and SVC coils deliver cardioversion and defibrillation
therapies. Pacing and sensing occur between the tip and
ring electrodes. An AccuRead analyzer cable interface tool (ACI
tool) is attached to the lead to facilitate accurate electrical
measurements during implant.
The tip electrode contains a steroid-eluting plug that contains
dexamethasone acetate. The tip electrode contains a nominal
dosage of 272 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 Package contents
Leads and accessories are supplied sterile. Each package
contains the following items:
●
1 lead with a radiopaque anchoring sleeve3, stylet, and
AccuRead tool
●
1 purple stylet guide
●
1 slit anchoring sleeve
●
1 vein lifter
●
extra stylets
●
product literature
1.2 Accessory descriptions
AccuRead analyzer cable interface (ACI) tool – The ACI tool
facilitates accurate electrical measurements during implant and
prevents possible connector damage.
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.
Purple stylet guide – A stylet guide facilitates stylet insertion into
the lead.
Slit anchoring sleeve – A slit anchoring sleeve secures excess
lead length in the device pocket.
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.
Vein lifter – A vein lifter facilitates lead insertion into a vein.
2 Drug component description
The active ingredients in the Model 6946M lead 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 shown below:
Dexamethasone acetate is a white to off-white, odorless powder
(USP) that is a practically insoluble in aqueous solutions.
Dexamethasone acetate is a synthetic adrenocortical steroid
produced by the esterification of dexamethasone.
Structural formula for dexamethasone acetate (DXAC) C24H31FO
6
1
Tensi-Lock is an exclusive Medtronic design feature that utilizes lead body cables to act like a built-in locking stylet and add tensile strength to the lead.
2
DF4-LLHH refers to the International Connector Standard ISO 27186:2010, where the lead connector contacts are defined as low voltage (L) or high voltage (H).
3
Two radiopaque anchoring sleeves are provided on leads that are 85 cm or longer.
3
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Figure 1.
The nominal dosage of dexamethasone acetate is 272 µg per
lead.
3 Indications
The lead is intended for single, long-term use in the right ventricle.
This lead has application for patients for whom implantable
cardioverter defibrillators (ICDs) are indicated.
4 Contraindications
Atrial use – The lead is contraindicated for the sole use of
detection and treatment of atrial arrhythmias.
Ventricular use – The lead is contraindicated for ventricular use
in patients with tricuspid valvular disease or a tricuspid
mechanical heart valve.
Transient ventricular tachyarrhythmias – The lead is
contraindicated for patients with transient ventricular
tachyarrhythmias due to reversible causes (drug intoxication,
electrolyte imbalance, sepsis, hypoxia) or other factors
(myocardial infarction, electric shock).
Steroid use – The lead is contraindicated in patients for whom a
single dose of 272 µg of dexamethasone acetate may
be contraindicated.
5 Warnings and precautions
Inspecting the sterile package – Inspect the sterile package
with care before opening it.
●
Contact a Medtronic representative if the seal or package is
damaged.
●
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.
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.
Connector compatibility – Although the lead conforms to the
International Connector Standard for DF4, do not attempt to use
the lead with any device other than a commercially available
implantable defibrillator 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.
Electrophysiologic testing – Prior to lead implant, it is strongly
recommended that patients undergo a complete cardiac
evaluation, which should include electrophysiologic testing. Also,
electrophysiologic evaluation and testing of the safety and
efficacy of the proposed pacing, cardioversion, or defibrillation
therapies are recommended during and after the implant of the
system.
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 the lead – Handle the lead with care at all times.
●
Protect the lead from materials that shed 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 use surgical instruments to grasp the lead or
connector pins.
●
Do not immerse the lead in mineral oil, silicone oil, or any other
liquid, except blood, at the time of implant.
●
Inserting the lead using a lead introducer that has a
hemostasis valve may require a larger introducer than the size
recommended. To avoid distortion of the coil electrode, do not
withdraw the lead through a hemostasis valve.
Handling the stylet – Handle the stylet with care at all times.
●
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.
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●
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.
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.
Second anchoring sleeve – Leads that are 85 cm or longer
include 2 anchoring sleeves. Use both anchoring sleeves to
assure adequate fixation.
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.
Magnetic resonance imaging (MRI) – An MRI is a type of
medical imaging that uses magnetic fields to create an internal
view of the body. Do not conduct MRI scans on patients who have
this device or lead implanted. MRI scans may result in serious
injury, induction of tachyarrhythmias, or implanted system
malfunction or damage.
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.
Chronic repositioning or removal – Chronic repositioning or
removal of leads may be difficult because of fibrotic tissue
development. Return all removed leads, or lead segments, to
Medtronic. If a lead must be removed or repositioned, proceed
with extreme caution.
●
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 may adversely affect the low-threshold
performance of a steroid-eluting 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.
AccuRead tool – The AccuRead tool reduces the risk of
connector damage, and reduces the risk of bridging and shorting
that may occur while taking electrical measurements during
implant. The potential for connector damage, bridging, and
shorting is due to variations in analyzer cable terminals, as well as
to the connector ring width and the proximity of the rings on the
DF4 connector.
6 Potential adverse events
Potential adverse events – The potential adverse events
associated with the use of transvenous leads and pacing systems
include, but are not limited to, the following events:
●
acceleration of tachyarrhythmias (caused by device)
●
air embolism
●
bleeding
●
body rejection phenomena, including local tissue reaction
●
cardiac dissection
●
cardiac perforation
●
cardiac tamponade
●
chronic nerve damage
●
constrictive pericarditis
●
death
●
device migration
●
endocarditis
●
erosion
●
excessive fibrotic tissue growth
●
extrusion
●
fibrillation or other arrhythmias
●
fluid accumulation
●
formation of hematomas/seromas or cysts
●
heart block
●
heart wall or vein wall rupture
●
hemothorax
●
infection
●
keloid formation
●
lead abrasion and discontinuity
●
lead migration/dislodgement
●
mortality due to inability to deliver therapy
●
muscle and/or nerve stimulation
●
myocardial damage
●
myocardial irritability
●
myopotential sensing
●
pericardial effusion
●
pericardial rub
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●
pneumothorax
●
poor connection of the lead to the device, which may lead to
oversensing, undersensing, or a loss of therapy
●
threshold elevation
●
thrombosis
●
thrombotic embolism
●
tissue necrosis
●
valve damage (particularly in fragile hearts)
●
venous occlusion
●
venous perforation
Other potential adverse events related to the lead include, but are
not limited to, the following conditions:
●
insulation failure
●
lead conductor or electrode fracture
Additional potential adverse events associated with the use of ICD
systems include, but are not limited to, the following events:
●
inappropriate shocks
●
potential mortality due to inability to defibrillate
●
shunting current or insulating myocardium during
defibrillation
7 Clinical data
Clinical study data – Clinical data from the Model 6947 and 4074
leads support the safety and efficacy of the Model 6946M lead.
The Model 6946M lead is a passive fixation model of the
Medtronic Sprint Quattro lead family, combining the Sprint
Quattrol lead body and the electrode tip of the Model 4074 lead.
The Model 6946M lead includes a combination of components
used in currently marketed Medtronic leads with some
enhancements.
All functional features of the Model 6946M lead have been
approved in these currently marketed Medtronic leads. Previous
clinical studies have shown leads with titanium nitride coated
electrodes, as used on Model 6946M, have clinically acceptable
pacing thresholds and sensing amplitudes. The length and
spacing of the defibrillation electrodes are identical to currently
approved Spring Quattro leads Model 6947 and Model 6947M.
Based upon its similarity to the Model 6947 and Model 4074
leads, the clinical data from these lead models support the safety
and efficacy of the Model 6946M lead. These relationships are
summarized in the following table.
Use of steroid-eluting plugUse of steroid-eluting plug
Passive fixation - tinesPassive fixation - tines
a
8 mm tip to ring spacing, 12 mm tip to RV coil spacing
clinical data supports:
Tip electrode material, titanium
nitride
Ring electrode material, titanium
nitride
For more information about the clinical data of these leads, you
can get printed copies of the Model 6947 and Model 4074
technical manuals from your Medtronic representative, or you can
call the toll-free number located on the back cover of this manual.
Information regarding the Model 6947 lead and Model 4074 lead
clinical study is also available on the Medtronic website. To view,
download, print, or order the Model 6947 and Model 4074
technical manual from the website, perform the following steps:
1. Navigate your Web browser to
http://www.medtronic.com/manuals.
2. Select the United States hyperlink.
3. Select the radio button for “by Model Number” and type
“6947” or “4074”.
4. Select one of the items from the drop-down list. Click Go. A
list of all technical literature for this device appears including
clinical summaries.
8 Drug information
8.1 Steroid 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.
8.2 Pharmacodynamics of the Model 6946M lead
Pharmacokinetics – The pharmacokinetics (local drug levels
and systemic levels) of dexamethasone acetate (DXAC) and its
metabolites following lead implantation were not evaluated in
human clinical trials.
Metabolism – The conversion of DXAC to dexamethasone
occurs within hours. The dexamethasone alcohol
(dexamethasone) is the active glucocorticoid used in Medtronic
leads. Steroid is applied to the tip and eluted through the electrode
6
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tip to the tissue interface where it will be used. Dexamethasone
1
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.
Mutagenesis, carcinogenicity and reproductive toxicology –
The mutagenesis, carcinogenicity, and reproductive toxicity of the
Model 6946M lead have not been evaluated. However, the
mutagenesis, carcinogenicity, and reproductive toxicity of
dexamethasone acetate has been evaluated previously.
Carcinogenesis, mutagenesis, impairment of fertility – No
adequate studies have been conducted in animals to determine
whether corticosteroid 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.
Pregnancy – Pregnancy category C. 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.
●
Connecting the lead
●
Placing the device and lead into the pocket
9.1 Opening the package
Use the following steps to open the sterile package and inspect
the lead:
1. Within the sterile field, open the sterile package and remove
the lead and accessories.
2. Inspect the lead. Leads that are shorter than 85 cm should
have 1 anchoring sleeve on the lead body. Leads that are
85 cm or longer should have 2 anchoring sleeves on the lead
body.
9.2 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, the subclavian 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 2).
Figure 2.
9 Directions for use
Proper surgical procedures and sterile techniques are the
responsibility of the medical professional. The following
procedures are provided for information only. Some implant
techniques vary according to physician preference and the
patient’s anatomy or physical condition. Each physician must
apply the information in these instructions according to
professional medical training and experience.
The implant procedure generally includes the following steps:
●
Opening the package
●
Inserting the lead
●
Positioning the lead
●
Taking electrical measurements and defibrillation efficacy
measurements
●
Anchoring the lead
1 Suggested entry site
●
Do not force the lead if significant resistance is
encountered during lead passage.
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●
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 3).
Note: A percutaneous lead introducer (PLI) kit may be used
to facilitate insertion. If an introducer is used, it should be at
least 3.0 mm (9 French). Refer to the technical manual
packaged with an appropriate percutaneous lead introducer
for further instructions.
Figure 3.
3. Advance the lead into the right atrium using a straight stylet to
facilitate movement through the veins.
9.3 Positioning the 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 pins.
Use the following steps to position the lead:
1. After the lead tip is passed into the atrium, advance the lead
through the tricuspid valve. Replace the straight stylet with a
gently curved stylet to add control when maneuvering the
lead through the tricuspid valve.
Caution: Do not use a sharp object to impart a curve to the
distal end of the stylet. Imparting a curve to the stylet can be
accomplished with a smooth-surface, sterile instrument
(Figure 4).
Figure 4.
Note: When you pass the lead tip through the tricuspid valve
or chordae tendineae, it may be difficult due to the flexible
nature of the lead body. Rotate the lead body as the tip
passes through the valve to facilitate passage.
2. After the lead tip is in the ventricle, the curved stylet may be
replaced with a straight stylet. Withdraw the stylet slightly, to
avoid using excessive tip force while achieving final
electrode position. Avoid known infarcted or thin wall areas to
minimize the occurrence of perforation.
9.4 Taking electrical measurements and
defibrillation efficacy measurements
Caution: Prior to taking electrical or defibrillation efficacy
measurements, move objects made from conductive materials,
such as guide wires, away from all electrodes. Metal objects, such
as guide wires, can short a lead and an active implantable device,
causing electrical current to bypass the heart and possibly
damage the implantable device and lead.
Caution: The ACI tool reduces the risk of connector damage, and
reduces the risk of bridging and shorting that may occur while
taking electrical measurements during implant. The potential for
connector damage, bridging, and shorting is due to variations in
analyzer cable terminals, as well as to the connector ring width
and the proximity of the rings on the DF4 connector.
Note: The ACI tool may be removed or attached at any time during
the procedure using the slit on the side of the tool (see Figure 5).
8
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Figure 5.
1 Removing the ACI tool from the connector pin
2 Removing the ACI tool from the stylet using the slit on the side of the
tool
Use the following steps to take electrical measurements:
1. Ensure that the lead connector is completely inserted into the
ACI tool. The connector pin will be completely accessible if
the ACI tool is properly attached (see Figure 6).
Figure 6.
2. Attach a surgical cable to the ACI tool. Line up the cable clips
with the contacts on the ACI tool to ensure that accurate
readings are obtained. (See Figure 13 for specific contacts.)
3. Use a testing device, such as a pacing system analyzer, for
obtaining electrical measurements (see Table 2 for
recommended measurements). For information on the use
of the testing device, consult the product literature for
that device.
4. After the electrical measurements are complete, remove the
surgical cable from the ACI tool before removing the tool from
the lead.
In order to demonstrate reliable defibrillation efficacy, obtain final
defibrillation measurements for the lead system.
Table 2. Recommended measurements at implant
(when using a pacing system analyzer)
Measurements
requiredAcutea lead system
Capture threshold
(at 0.5 ms pulse width)
Pacing impedance200–1000 Ω200–1000 Ω
≤1.0 V≤3.0 V
Chronicb lead sys-
tem
Table 2. Recommended measurements at implant
(when using a pacing system analyzer) (continued)
Measurements
requiredAcutea lead system
Filtered R-wave
amplitude (during
sinus rhythm)
Slew rate≥0.75 V/s≥0.45 V/s
a
<30 days after implant.
b
>30 days after implant.
≥5 mV≥3 mV
Chronicb lead sys-
tem
If initial electrical measurements deviate from the recommended
values, it may be necessary to repeat the testing procedure 15 min
after final positioning. Initial electrical measurements may deviate
from the recommended values:
●
Initial impedance values may exceed the measuring
capabilities of the testing device, resulting in an error
message.
●
Values may vary depending upon lead type, implantable
device settings, cardiac tissue condition, and drug
interactions.
If electrical measurements do not stabilize to acceptable levels, it
may be necessary to reposition the lead and repeat the testing
procedure.
In order to keep patient morbidity and mortality to a minimum,
patients should be rescued promptly with an external defibrillator
if the implanted lead system fails to terminate a VF episode. At
least 5 min should elapse between VF inductions.
For more information about obtaining electrical measurements,
consult the product documentation supplied with the testing
device.
9.5 Anchoring the lead
Caution: Use care when anchoring the lead.
●
Use only nonabsorbable sutures to anchor the lead.
●
Do not attempt to remove or cut the anchoring sleeve from the
lead body.
●
During lead anchoring, take care to avoid dislodging the
lead tip.
●
Do not secure sutures so tightly that they damage the vein,
lead, or anchoring sleeve (Figure 7).
●
Do not tie a suture directly to the lead body (Figure 7).
Figure 7.
Use the following steps to anchor the lead using all 3 grooves:
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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.
1. Position the distal anchoring sleeve against or near the vein.
2. Secure the anchoring sleeve to the lead body by tying a
suture firmly in each of the 3 grooves (Figure 8).
Figure 8.
3. Use at least one additional suture in one of the grooves to
secure the anchoring sleeve and lead body to the fascia.
4. A second anchoring sleeve is provided with leads that are
85 cm or longer. For abdominal implants, the redundant lead
body (for example, a curve for strain relief) should be placed
just proximal to the first anchoring sleeve. Then, the second
anchoring sleeve may be lightly sutured to the lead body and
fascia to hold the curve in place. This procedure helps isolate
the vein entry site from tension on the proximal end of the
lead body.
5. A slit anchoring sleeve may be used in the device pocket to
secure excess lead length. First, secure the anchoring
sleeve to the lead body. Then, orient the slit toward the fascia
and secure the anchoring sleeve to the fascia with sutures.
9.6 Connecting the lead
Figure 9. Lead connector pin viewing area
1 Lead tip extends past setscrew block; lead connector pin is visible in
pin viewing area (color band may be used to verify full lead insertion)
2 Setscrew block, located behind grommet
3 Lead
9.7 Placing the device and lead into the pocket
Caution: Use care when placing the device and leads into
the pocket.
●
Ensure that the leads do not leave the device at an acute
angle.
●
Do not grip the lead or device with surgical instruments.
●
Do not coil the lead. Coiling the lead can twist the lead body
and may result in lead dislodgement (Figure 10).
Figure 10.
Use the following steps to connect the lead to an implantable
device:
1. Make sure that the stylet and all accessories have been
completely removed. When removing the accessories, grip
the lead firmly just below the ACI tool on the connector to
prevent dislodgement.
2. Push the lead or plug into the header block until the color
band on the tip of the lead connector pin is visible in the pin
viewing area (see Figure 9). The color band will be visible
when the lead is fully inserted. Consult the product literature
packaged with the implantable device for instructions on
proper lead connections.
10
Use the following steps to place the device and leads into the
pocket:
1. To prevent undesirable twisting of the lead body, rotate the
device to loosely wrap the excess lead length (Figure 11).
Figure 11.
2. Insert the device and leads into the pocket.
Page 11
3. Before closing the pocket, verify sensing, pacing,
cardioversion, and defibrillation efficacy.
9.8 Post-implant evaluation
After implant, monitor the patient’s electrocardiogram until the
patient is discharged. If a lead dislodges, it usually occurs during
the immediate postoperative period.
Recommendations for verifying proper lead positioning include
x-rays and pacing and sensing thresholds taken at pre-hospital
discharge, 3 months after implant, and every 6 months thereafter.
In the event of a patient death, explant all implanted leads and
devices and return them to Medtronic with a completed Product
Information Report form. Call the appropriate phone number on
the back cover if there are any questions on product handling
procedures.
10 Specifications (nominal)
10.1 Detailed device description
Table 3. Specifications (nominal)
ParameterModel 6946M
TypeQuadripolar
PositionRight ventricle
FixationTined
Length20–110 cm
ConnectorQuadripolar/true
MaterialsConductors: MP35N coil
Tip electrode (pace, sense): Sintered platinum alloy with Tita-
DF4 pin and rings: MP35N
SteroidType: Dexamethasone acetate
Conductor
resistances
DiametersLead body: 2.8 mm
Pacing (unipolar): 27.9 Ω (62 cm)
bipolar:
Insulation: Silicone, PTFE, ETFE
Overlay: Polyurethane
Seal Zone: PEEK
Ring electrode
(pace, sense):
RV/SVC coils: Platinum-clad tantalum
DF4 pin: MP35N
Amount: 272 µg
Steroid binder: Silicone
Pacing (bipolar): 29.3 Ω (62 cm)
Defibrillation: 1.4 Ω (62 cm)
Four-pole inline (DF4–LLHH)
MP35N composite cables
nium Nitride (TiN) coating
Platinum alloy with Titanium
Nitride (TiN) coating
Tip: 2.8 mm
Table 3. Specifications (nominal) (continued)
ParameterModel 6946M
Lead introducer (recommended
size)
without guide wire: 3.0 mm (9.0 French)
with guide wire: 3.7 mm (11 French)
Figure 12. 6946M distal lead components
11
Page 12
1 Tip electrode; surface area: 2.5 mm
2 Ring electrode; surface area: 25.2 mm
3 RV coil electrode; length: 57 mm; surface area: 614 mm2; electrical
5 Anchoring sleeve; leads 85 cm or longer have 2 anchoring sleeves
2
2
2
2
Figure 13. Model 6946M proximal lead components
5 RV contact
6 Ring (+) contact
7 Tip (-)
11 Medtronic warranty
For complete warranty information, see the accompanying
warranty document.
12 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 Explanation of symbols on package labeling
Refer to the package labels to see which symbols apply to this
product.
Table 4. Explanation of symbols on package labeling
SymbolExplanation
Conformité Européenne (European Conformity).
This symbol means that the device fully complies
with AIMD Directive 90/385/EEC (0123).
Toll-free in the USA (24-hour technical consultation for
physicians and medical professionals)
Bradycardia: +1 800 505 4636
Tachycardia: +1 800 723 4636
Europe/Middle East/Africa
Medtronic International Trading Sàrl
Route du Molliau 31
Case Postale 84
CH-1131 Tolochenaz
Switzerland
+41 21 802 7000