Medtronic 6935 Technical Manual

SPRINT QUATTRO SECURE S™ 6935

Steroid-eluting, tripolar, screw-in, ventricular lead with RV defibrillation coil electrode

Technical Manual

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

The following are trademarks or registered trademarks of Medtronic in the United States and possibly in other countries:

Medtronic, Sprint Quattro, Sprint Quattro Secure, Sprint Quattro Secure S

Contents

1 Description 3
2 Drug component description 3
3 Indications 4
4 Contraindications 4
5 Warnings and precautions 4
6 Potential complications 5
7 Drug Information 6
8 Adverse events and clinical trial data 6

9 Implant procedure 6
10 Specifications (nominal) 11
11 Medtronic warranty 12
12 Service 12

1 Description

The Medtronic Sprint Quattro Secure S Model 6935 lead is a
steroid-eluting, tripolar, screw-in, ventricular lead with a right
ventricular (RV) defibrillation coil electrode. The lead is designed
for pacing, sensing, cardioversion, and defibrillation therapies.

The lead features an extendable/retractable helix electrode,
silicone insulation with overlay, and parallel conductors. The 3
electrodes of the lead are the helix, ring, and RV coil. The ring and
helix electrodes are platinized. See Figure 13 for an illustration of
the lead.

●

The helix electrode is common to the connector pin of the
IS-11 BI pin connector.

●

The ring electrode is common to the connector ring of the IS-1
BI connector.

●

The RV coil electrode is common to the connector pin of the
RV DF-12 connector (red band).

The RV coil delivers cardioversion and defibrillation therapies.
Pacing and sensing occur between the helix and ring electrodes.

The helix electrode is made of platinized platinum alloy that can
be actively fixed into the endocardium. The helix electrode can
be extended or retracted by rotating the IS-1 connector pin with
the fixation tool.

The IS-1 bipolar leg of the bifurcation features a lumen for stylet
passage. The DF-1 connector legs will not accept a stylet.

The distal tip of the lead contains a maximum of 1.0 mg
dexamethasone sodium phosphate. 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 1 radiopaque anchoring sleeve3, stylet, and stylet
guide

●

2 fixation tools

●

1 slit anchoring sleeve

●

1 vein lifter

●

2 pin caps

●

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.

Fixation tool – The fixation tool facilitates connector pin rotation.

Pin cap – A pin cap covers and insulates unused connector pins.

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 length.

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 6935 lead is dexamethasone
sodium phosphate [9-fluoro-11β,
17-dihydroxy-16α-methyl-21-(phosphonooxy)
pregna-1,4-diene-3,20-dione disodium salt]. Dexamethasone
sodium phosphate (DSP) is an inorganic ester of
dexamethasone, a synthetic adrenocortical steroid. DSP is a
white or slightly yellow crystalline powder. It is freely soluble in
water and is very hygroscopic.

The structural formula for this steroid is shown below.

1

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

2

DF-1 refers to the International Connector Standard (ISO 11318) whereby pulse generators and leads so designated are assured of a basic mechanical fit.

3

Two radiopaque anchoring sleeves are provided with leads 85 cm or longer.

3

Figure 1. Structural formula for dexamethasone sodium
phosphate C22H28FNa2O8P

The maximum dosage of dexamethasone sodium phosphate is
less than 1.0 mg 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 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 – Use of steroid eluting transvenous leads is
contraindicated in patients for whom a single dose of 1.0 mg
dexamethasone sodium phosphate may be contraindicated.

5 Warnings and precautions

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 – People with metal implants such as pacemakers,
implantable cardioverter defibrillators (ICDs), and accompanying
leads should not receive diathermy treatment. The interaction

between the implant and diathermy can cause tissue damage,
fibrillation, or damage to the device components, which could
result in serious injury, loss of therapy, and/or the need to
reprogram or replace the device.

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.

Single use – The lead is for single use only.

Inspecting the sterile package – Inspect the sterile package

with care before opening it.

●

Contact a Medtronic representative if the seal or package is
damaged.

●

Do not store this product above 40 °C (104 °F).

●

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 sodium phosphate apply to the use of this highly
localized, controlled-release device. 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.

Drug interactions – Drug interaction of dexamethasone sodium
phosphate with this lead has not been studied.

Use of multiple leads – Prior to implanting the lead, total patient
exposure to dexamethasone sodium phosphate should be
considered.

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.

4

●

Inserting the lead using a lead introducer that features 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.

●

Do not implant the lead without first verifying the mechanical
functioning of the helix electrode. Refer to Section 9.2,
“Verifying the mechanical functioning of the helix electrode”,
page 7, for complete instructions.

●

Do not rotate the helix electrode after it is fully extended or
fully retracted. The number of rotations required to fully
extend or retract the helix electrode is variable.

●

Furthermore, do not exceed the recommended maximum
number of rotations to extend or retract the helix electrode.
Exceeding the maximum number may result in fracture or
distortion of the inner conductor or helix electrode. Refer to
Section 10 for the recommended maximum number
of rotations.

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.

●

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 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 does not disengage from the endocardium by
rotating the connector pin, rotating the lead body
counterclockwise may withdraw the helix 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.

Second anchoring sleeve – Leads 85 cm or longer feature
2 anchoring sleeves. Use both anchoring sleeves to assure
adequate fixation.

Connector compatibility – Although the lead conforms to the
International Connector Standards IS-1 and DF-1, 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.

6 Potential complications

The potential complications 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

●

constrictive pericarditis

●

embolism

●

endocarditis

●

fibrillation or other arrhythmias

●

heart wall rupture

●

hemothorax

●

infection

●

pneumothorax

●

thrombosis

●

tissue necrosis

Other potential complications related to the lead include, but are
not limited to, the following complications:

●

insulation failure

●

lead conductor or electrode fracture

●

lead dislodgment

●

poor connection to the device, which may lead to
oversensing, undersensing, or a loss of therapy

5

7 Drug Information

7.1 Steroid mechanism of action

Steroid suppresses the inflammatory response that is believed to
cause threshold rises typically associated with implanted pacing
electrodes. Dexamethasone sodium phosphate 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 Pharmacodynamics of the Model 6935 lead

Pharmacokinetics – The pharmacokinetics (local drug levels

and systemic levels) of dexamethasone sodium phosphate and
its metabolites following lead implantation were not evaluated in
human clinical trials.

The in-vivo elution profile of a tined pacemaker lead with a DSP
monolithic controlled release device, based upon an assay of
explanted leads, is shown in Mond and Stokes4.

Metabolism – The conversion of DSP to dexamethasone occurs
within minutes. The dexamethasone alcohol (dexamethasone) is
the active glucocorticoid used in Medtronic leads. Steroid is
applied to the tip and eluted through the electrode tip to the tissue
interface where it will be used. Dexamethasone sodium
phosphate 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 6935 lead have not been
evaluated. However, the mutagenesis, carcinogenicity, and
reproductive toxicity of dexamethasone sodium phosphate have
previously been evaluated.

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 sodium
phosphate 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 sodium phosphate 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, spontaneous abortions, and 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.

8 Adverse events and clinical trial data

Information regarding the Model 6935 lead clinical study and
adverse events is available at www.medtronic.com/manuals. To
view, download, print, or order the clinical study from the
Medtronic website:

1. Navigate your web browser to
www.medtronic.com/manuals.

2. Set the “Your Location” option to United States and click
[OK].

3. Select the “Model # or Name” field on the left side of the
screen and type “6935.”

4. Click [Search]. All technical literature for this lead will be
listed.

The following clinical studies are related to this device:

●

Model 6932 RV Lead clinical study

●

Model 6947 RV Lead clinical study

9 Implant procedure

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.

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 shorter than 85 cm should have
1 anchoring sleeve on the lead body. Leads 85 cm or longer
should have 2 anchoring sleeves on the lead body.

4

Mond, H. and Stokes, K.B., The Electrode - Tissue Interface: The Revolutionary Role of Steroid Elution, Pacing and Clinical Electrophysiology, Vol. 15, No. 1, pp
95-107

6

9.2 Verifying the mechanical functioning of the helix electrode

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

1. With a stylet inserted into the lead, press both legs of the
fixation tool together and place the most distal hole on the
IS-1 connector pin (Figure 2).
Note: The stylet guide may be removed by gently pulling it
off. To reattach a stylet guide, gently push it onto the
connector pin.

Figure 2.

2. Hold the IS-1 connector leg of the lead with the thumb on one
side and 4 fingers on the other side. Keep the lead body and
the IS-1 connector leg as straight as possible. Ensure that
the stylet is fully inserted, then rotate the fixation tool
clockwise until the helix electrode is fully extended
(Figure 3). When the helix electrode is fully extended,
approximately 1.5 to 2 helix coils are exposed.

Figure 3.

the lead is bent on either side of the lead bifurcation during
helix electrode extension or retraction, the lead may be
damaged.

Figure 4.

Caution: Over-rotating the connector pin after the helix

electrode is fully extended or fully retracted may damage the
lead. The number of rotations required to extend or retract
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.
Rotation should be stopped once full helix retraction is
visually verified. Over-retraction of the helix may result in the
inability to extend the helix. If the helix is unable to extend,
use a new lead.
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 turns
for extension.

3. Disconnect the 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
fixation tool and rotate it counterclockwise until the helix
electrode tip is retracted into the sheath.

9.3 Inserting the lead

Caution: Do not severely bend the IS-1 connector leg or the

lead body while extending the helix electrode (Figure 4). If

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.

7

Cautions:

1

●

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 5).

Figure 5.

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 6).
Note: A percutaneous lead introducer (PLI) kit may be used
to facilitate insertion. Refer to the technical manual
packaged with an appropriate percutaneous lead introducer
for further instructions.

Figure 6.

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

9.4 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 7).

Figure 7.

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.

3. Proper positioning of the helix electrode is essential for
stable endocardial pacing. A satisfactory position usually is
achieved when the lead tip points straight toward the apex,
or when the distal end dips or bends slightly. Use fluoroscopy
(lateral position) to ensure that the tip is not in a retrograde
position or lodged in the coronary sinus.
Note: With the helix electrode retracted, the distal end of the
lead may be used to map a desirable site for electrode
fixation. Mapping may reduce the need to repeatedly extend
and fixate the helix electrode.

4. After placing the lead in a satisfactory position, extend the
helix electrode by following the procedure in Section 9.5.

9.5 Securing the helix electrode into the endocardium

Secure the helix electrode using the following techniques:

1. Press both legs of the fixation tool together and place the
most distal hole on the IS-1 connector pin (Step 1).

8

2. Press the lead tip against the endocardium by gently pushing

A B

AB

the stylet and lead at the vein entry site.

3. Rotate the fixation tool clockwise until the helix electrode is
fully extended.
Caution: Do not severely bend the IS-1 connector leg or the
lead body while extending the helix electrode. If the lead is
bent on either side of the lead bifurcation during helix
electrode extension or retraction, the lead may be damaged.
Use fluoroscopy to verify helix electrode extension. The
fluoroscope head may need to be rotated to obtain an
adequate view. Both a visual and fluoroscopic view of a fully
retracted and extended helix electrode is shown in
Figure 8.
Closing of the space between the indicator stop (A) and the
indicator ring (B) implies complete extension of the helix
electrode.

Figure 8.

1 Fully retracted visual
2 Fully retracted fluoroscopic
3 Fully extended visual
4 Fully extended fluoroscopic

Cautions:

●

The number of rotations required to fully extend or retract
the helix electrode is variable. Rotation should be
stopped once full helix extension or retraction is verified
with fluoroscopy as shown in Figure 8. Over-retraction
of the helix, during initial implant or subsequent
repositioning, may result in the inability to extend the
helix. If the helix is unable to extend, replace with a new
lead.

●

Do not exceed the recommended maximum number of
rotations to extend or retract the helix electrode.
Exceeding the maximum number may result in fracture
or distortion of the inner conductor or helix electrode.
Refer to Section 10 for the recommended maximum
number of rotations.

●

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

4. Remove the 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.

5. To assure helix electrode fixation, leave the stylet in place,
hold the lead by the connector, and carefully rotate the lead
body in 2 clockwise rotations.

6. Partially withdraw the stylet.

7. Obtain electrical measurements to verify satisfactory
placement and electrode fixation. Refer to Section 9.6,
“Taking electrical measurements and defibrillation efficacy
measurements”, page 9.

8. Verify that the lead is affixed. Gently pull back on the lead,
and check for resistance to verify fixation. 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.

9. If repositioning is required, reattach the fixation tool, and
rotate counterclockwise until the helix electrode is retracted.
Use fluoroscopy to verify withdrawal of the helix electrode
before attempting to reposition.

10. After final positioning, make sure that the stylet and the stylet
guide have been completely removed. When removing the
stylet guide, grip the lead firmly just below the connector pin
to help prevent lead dislodgment.

11. Obtain final electrical measurements. Refer to Section 9.6.

9.6 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.

Use the following steps to take electrical measurements:

1. Attach a surgical cable to the lead connector pin. A notch in
the style guide allows connection of a surgical cable for
obtaining electrical measurements.

2. Use a testing device, such as a pacing system analyzer, for
obtaining electrical measurements. For information on the
use of the testing device, consult the product documentation
for that device.

In order to demonstrate reliable defibrillation efficacy, obtain final
defibrillation measurements for the lead system.

Table 1. Recommended measurements at implant (when using a pacing system analyzer)

Measurements
required Acutea lead system

Capture threshold
(at 0.5 ms pulse width)

Pacing impedance 200–1000 Ω 200–1000 Ω

≤1.0 V ≤3.0 V

Chronicb lead sys-

tem

9

Table 1. Recommended measurements at implant
(when using a pacing system analyzer) (continued)

Measurements
required Acutea 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 on obtaining electrical measurements,
consult the product documentation supplied with the testing
device.

9.7 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 9).

●

Do not tie a suture directly to the lead body (Figure 9).

Figure 9.

Use the following steps to anchor the lead using all 3 grooves:

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 10).

Figure 10.

3. Use at least 1 additional suture in 1 of the grooves to secure
the anchoring sleeve and lead body to the fascia.

4. A second anchoring sleeve is provided with leads 85 cm or
longer. For abdominal implants, 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.

9.8 Connecting the lead

Use the following steps to connect the lead to an implantable
device:

1. Carefully remove the stylet and stylet guide. When removing
the stylet and stylet guide, grip the lead firmly just below the
connector pin to prevent dislodgment.

2. Insert the lead connectors into the lead connector block.
Consult the product documentation packaged with the
implantable device for instructions on proper lead
connections.

9.9 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 dislodgment (Figure 11).

10

Figure 11.

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 12).

Figure 12.

2. Insert the device and leads into the pocket.

3. Before closing the pocket, verify sensing, pacing,
cardioversion, and defibrillation efficacy.

9.10 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/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 2. Specifications (nominal)

Parameter Model 6935

Type Tripolar

Position Right ventricle

Fixation Extendable/retractable helix

Length 40–110 cm

Connectors Unipolar: DF-1

Bipolar: IS-1

Materials Conductors: MP35N coil

Insulation: Silicone, PTFE, ETFE

Overlay: Polyurethane

Electrodes (pace, sense): Platinized platinum alloy

RV coil: Platinum-clad tantalum

DF-1 pin: Stainless steel

IS-1 pin and rings: Stainless steel

Steroid Type: Dexamethasone sodium phos-

Amount: 1.0 mg maximum

Steroid binder: Polyurethane

Conductor
resistances

Helix length (extended) 1.8 mm

Diameters Lead body: 2.8 mm

Lead introducer (recommended
size)

Pacing (unipolar): 29 Ω (65 cm)

Pacing (bipolar): 32.3 Ω (65 cm)

Defibrillation: <1.2 Ω (65 cm)

without guide wire: 3.0 mm (9.0 French)

with guide wire: 3.7 mm (11.0 French)

Table 3. Maximum number of rotations to extend or retract the helix electrode

Lead length Number of rotations

52 cm 16

58 cm 18

65 cm 20

75 cm 22

100 cm 27

MP35N composite cables

phate

Tip: 2.8 mm

Helix: 1.4 mm

11

Figure 13. Model 6935 distal lead components

7

8

7 DF-1 connector (red band): connector pin is common to RV coil

electrode

8 IS-1 BI connector: connector pin is common to tip electrode;

connector ring is common to ring electrode

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 address or telephone
number listed on the back cover.

1 Helix electrode, surface area: 5.7 mm
2 Ring electrode, surface area: 25.2 mm
3 RV coil electrode, length: 57 mm; surface area: 614 mm2; electrical

shadow area: 506 mm
4 Anchoring sleeve: leads 85 cm or longer have 2 anchoring sleeves
5 Helix electrode to ring electrode, length 8 mm
6 Helix electrode to RV coil, length: 12 mm

12

2

2

2

World Headquarters

*M945870A001*

Medtronic, Inc.
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Minneapolis, MN 55432-5604
USA
www.medtronic.com
Tel. [phone]
Fax [phone]

Medtronic USA, Inc.

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/Africa/Middle East Headquarters

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www.medtronic.com
Tel. [phone]
Fax [phone]

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Representative/Distributed by

Medtronic B.V.
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The Netherlands
Tel. [phone]
Fax [phone]

Technical manuals:
www.medtronic.com/manuals

© Medtronic, Inc. 2010
M945870A001A
2010-10-20