SPRINT QUATTRO SECURE® 6947 DXAC/DSP
Dexamethasone acetate and dexamethasone sodium phosphate steroid-eluting, quadripolar, screw-in,
ventricular lead with RV/SVC defibrillation coil electrodes
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
Contents
1 Device description 3
2 Indications 3
3 Drug component description 3
4 Contraindications 4
5 Warnings and precautions 4
6 Drug information 5
7 Pharmacodynamics of the Model 6947 lead 5
8 Adverse events 6
9 Clinical study 6
10 Directions for use 7
11 Specifications (nominal) 12
12 Medtronic warranty 13
13 Service 13
1 Device description
The Medtronic Sprint Quattro Secure Model 6947 lead is a
steroid-eluting, quadripolar, screw-in, 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 an extendable and retractable helix electrode,
silicone insulation, and parallel conductors. The four electrodes
of the lead are the helix, ring, RV coil, and SVC coil.
●
The tip electrode is common to the connector pin of the
IS-11 BI connector.
●
The ring electrode is common to the connector pin 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 SVC coil electrode is common to the connector pin of the
SVC DF-1 connector (blue band).
The RV and SVC coils deliver cardioversion and defibrillation
therapies. Pacing and sensing occur between the helix and
ring electrodes.
The lead features a helix electrode made of platinized platinum
alloy that can be actively fixed into the endocardium. The helix
electrode can be extended or retracted by using a fixation tool to
rotate the IS-13 connector pin.
The IS-1 bipolar leg of the trifurcation features a lumen for stylet
passage. The DF-14 connectors do not accept stylets.
The steroid dexamethasone sodium phosphate (DSP) is located
on the lead tip surface. The lead tip also incorporates a
steroid-eluting ring containing dexamethasone acetate (DXAC).
The lead tip contains a maximum of 1.0 mg dexamethasone.
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 one radiopaque anchoring sleeve5, stylet, and
stylet guide
●
1 slit anchoring sleeve
●
1 vein lifter
●
2 fixation tools
●
2 pin caps
●
extra stylets
●
product literature
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 – A 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 corresponding lead length.
Stylet guide – A stylet guide facilitates stylet insertion into the
lead.
Vein lifter – A vein lifter facilitates lead insertion into a vein.
2 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.
3 Drug component description
The active ingredients in the 6947 lead are dexamethasone
acetate [21-(acetyloxy)-9-fluoro-11β,
17-trihydroxy-16α-methylpregna-1,4-diene-3,20-dione] and
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
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.
4
DF-1 refers to the International Connector Standard (ISO 11318) whereby pulse generators and leads so designated are assured of a basic mechanical fit.
5
Two radiopaque anchoring sleeves are provided with leads 85 cm or longer.
3
dexamethasone sodium phosphate [9-fluoro-11β,
17-dihydroxy-16α-methyl-21-(phosphonooxy)
pregna-1,4-diene-3,20-diene-3,20-dione disodium salt].
The structural formula for each of these steroids is shown below:
Figure 1. Structural formula for dexamethasone sodium phosphate (DSP)
Dexamethasone sodium phosphate is an inorganic ester of
dexamethasone, a synthetic adrenocortical steroid.
Dexamethasone sodium phosphate is a white or slightly yellow
crystalline powder. It is freely soluble in water and is very
hygroscopic.
Figure 2. Structural formula for dexamethaxone acetate (DXAC)
Dexamethasone acetate is a white to practically white, odorless
powder. Dexamethasone acetate is a practically insoluble ester
of dexamethasone, a synthetic adrenocortical steroid.
The maximum dosage of dexamethasone sodium phosphate and
dexamethasone acetate is less than 1.0 mg per lead.
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
combined dose of 1.0 mg of dexamethasone sodium phosphate
and dexamethasone acetate may be contraindicated.
5 Warnings and precautions
Single use – The lead is for single use only.
Inspecting the sterile package – Inspect the sterile package
before opening it.
●
If the seal of the package is damaged, contact a Medtronic
representative.
●
Do not store this product above 40 °C (104 °F).
●
Do not use the product after its expiration date.
Ethylene oxide resterilization – The lead has been sterilized
with ethylene oxide prior to shipment. If the integrity of the sterile
package has been compromised prior to the expiration date,
resterilize using ethylene oxide. Avoid resterilization techniques
that could damage the lead.
●
Refer to sterilizer instructions for operating instructions.
●
Use an acceptable method for determining sterilizer
effectiveness, such as biological indicators.
●
Do not exceed temperatures of 130 °F (55 °C).
●
Do not resterilize more than one time.
●
After sterilization, allow the device to aerate ethylene oxide
residues.
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 sodium phosphate or dexamethasone acetate
apply to the use of this highly localized, controlled-release lead.
For a list of potentially 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 shedding 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.
4
●
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 leads in mineral oil, silicone oil, or any
other liquid, except blood, at the time of implantation.
●
Do not implant the lead without first verifying the mechanical
functioning of the helix electrode. Refer to Section 10.2,
“Verifying the mechanical functioning of the helix electrode”,
page 8 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 11.1,
“Detailed device description”, page 12 for the
recommended maximum number of rotations.
●
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.
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.
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.
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.
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.
6 Drug information
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 and dexamethasone acetate
are synthetic steroids 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 Pharmacodynamics of the Model 6947 lead
Pharmacokinetics – The pharmacokinetics (local drug levels
and systemic levels) of dexamethasone acetate (DXAC) and
dexamethasone sodium phosphate (DSP) and their metabolites
following lead implantation were not evaluated in human clinical
trials.
5
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