Steroid eluting, transvenous, bipolar, left ventricular, over the wire, cardiac vein pacing lead
Technical Manual
Caution: Federal law (USA) restricts this device to sale by or on the order of a physician.
Page 2
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.
Attain, InSync, Medtronic
Page 3
Contents
1 Required physician training3
2 Device description3
3 Indications for use4
4 Contraindications4
5 Warnings and precautions4
6 Potential adverse events5
7 Clinical trials6
8 Directions for use9
In order to implant a Medtronic Attain Bipolar OTW 4194 lead,
physicians are required to:
●
Thoroughly read this manual, and all associated device
technical manuals.
●
Provide a copy of the patient manual to the patient and
discuss it with him or her and any other interested parties.
●
Be trained on the following topics
– Indications for use
– Device operation to ensure therapy delivery
– Measuring and managing biventricular thresholds
– Assembly and use of LV lead implant tools
– Placement of the LV lead
– Patient management and system follow-up
Prior to implanting the system, Medtronic will certify that
physicians received training.
2 Device description
The Medtronic Attain Bipolar OTW 4194 steroid eluting,
transvenous, bipolar, left ventricular, over the wire, cardiac vein
pacing lead is designed for pacing and sensing via a cardiac vein,
as part of a Medtronic biventricular pacing system. The tip to
anode spacing is 11 mm.
The lead features a tapered annular platinum alloy electrode tip
and a platinum/iridium anode coil. The electrode tip contains a
molded silicone rubber seal. This molded tip provides a fluid seal
which allows guide wire passage and reduces blood ingress. The
lead also features nickel alloy conductors, polyurethane outer
insulation, silicone inner insulation, and an IS-11 Bipolar (BI) lead
connector.
The lead’s distal tip 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.
The Model 4194 lead can be positioned with the aid of a guide wire
or with a stylet. If a stylet is used, use only the stylets packaged
with the lead or in a stylet kit (downsized knob).
Note: To implant the Model 4194 lead in a cardiac vein, a
compatible delivery system is required, such as a Medtronic
delivery system. A compatible delivery system includes a guide
catheter and a hemostasis/introducer valve which allows
passage through or removal from an IS-1 connector. Contact your
Medtronic representative for further information regarding
compatible delivery systems.
2.1 Contents of package
The lead and accessories are supplied sterile. Each package
contains the following items:
●
1 lead with stylet and anchoring sleeve
●
2 guide wire insertion tools
●
1 guide wire clip
●
1 guide wire steering handle
●
Extra stylets
●
Product documentation
2.2 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.
Guide wire clip – A guide wire clip secures the excess guide wire
and helps to protect and maintain the sterility of the guide wire.
Guide wire insertion tool – A guide wire insertion tool provides
additional control when inserting a guide wire into the lead
connector pin or the lead tip.
Guide wire steering handle – A guide wire steering handle is
used only with guide wires 0.46 mm (0.018 in) or less in diameter.
The steering handle provides additional control and steerability of
the guide wire.
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 BI refers to an International Connector Standard (ISO 5841–3) whereby pulse generators and leads so designated are assured of a basic mechanical fit.
3
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3 Indications for use
The lead has application as part of a Medtronic biventricular
pacing system.
4 Contraindications
Coronary vasculature – This lead is contraindicated for patients
with coronary venous vasculature that is inadequate for lead
placement, as indicated by venogram.
Steroid use – The lead is contraindicated in patients for whom a
single dose of 1.0 mg of dexamethasone sodium phosphate may
be contraindicated.
5 Warnings and precautions
For single use only – Do not resterilize and reimplant an
explanted 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.
Backup pacing should be readily available during implant. Use of
the delivery system or leads may cause heart block.
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.
Inspecting the sterile package – Carefully inspect the package
prior to opening.
●
If the seal or package is damaged, contact your local
Medtronic representative.
●
Do not use the product after its expiration date.
●
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 the lead
using ethylene oxide.
Ethylene oxide resterilization – If the sterile package seal is
broken, resterilize the device using a validated ethylene oxide
process. Avoid resterilization techniques that could damage the
lead.
●
Refer to sterilizer instructions for operating instructions.
●
Use an acceptable method to determine sterilizer
effectiveness, such as biological indicators.
●
Before resterilization, place the device in an ethylene oxide
permeable package.
●
Do not exceed temperatures of 55 °C (131 °F).
●
Do not resterilize more than one time.
●
Allow proper aeration of ethylene oxide residues prior to
implant.
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 – Reducing the available amount of
steroid may adversely affect low-threshold performance. Avoid
reducing the amount of steroid available prior to lead implant.
●
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 – Leads should be handled with care at all
times:
●
Do not withdraw the lead through a non-adjustable
hemostasis/introducer valve. This action could cause
distortion of the coil electrode and result in potential injury to
the patient.
●
If a stylet is used for lead positioning, use only the stylets
packaged with the lead or in a stylet kit (downsized knob).
Other stylets may extend beyond the lead tip causing lead tip
seal damage or patient injury.
●
If the lead is damaged, do not implant it. Return the lead to a
Medtronic representative.
●
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
pin.
●
Do not immerse leads in mineral oil, silicone oil, or any other
liquid, except blood, at the time of implant.
●
Use an anchoring sleeve with all leads. Ensure that the
anchoring sleeve is positioned close to the lead connector
pin, to 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.
●
Do not force the guide catheter or leads if significant
resistance is encountered. Use of guide catheters or leads
may cause trauma to the heart.
4
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Handling the guide wire – Handle the guide wire with care at all
times.
●
Damage to a guide wire may prevent the guide wire from
performing with accurate torque response and control and
may cause vessel damage. For additional information about
vessel damage and other potential adverse events, refer to
the technical manual packaged with the appropriate guide
wire.
●
If the distal end of the guide wire becomes severely kinked or
twisted, it may be difficult to withdraw it back through the lead.
Therefore, if there is an indication that the distal end of the
guide wire has become damaged, or if there is significant
resistance in guide wire passage, remove the lead and guide
wire together as a unit. Remove the guide wire from the lead
and insert a new guide wire into the lead. Do not use
excessive force to retract the guide wire from the lead.
Refer to the product documentation packaged with the guide
wire for additional information.
Handling the stylet – Handle the stylet with care at all times.
●
To minimize the likelihood of trauma to the vein and to
maintain lead flexibility while advancing the lead through the
vein, keep the stylet withdrawn 1 to 2 cm or select a more
flexible stylet.
●
Do not use excessive force or surgical instruments when
inserting a stylet.
●
Avoid overbending, kinking, or blood contact on stylets.
●
Use a new stylet when blood or other fluids accumulate on the
stylet. Accumulated fluids may cause damage to the lead or
difficulty in passing the stylet through the lead.
●
Curving the distal end of the stylet prior to insertion into the
lead will achieve a curvature at the distal end of the lead. Do
not use a sharp object to impart a curve to the distal end of the
stylet.
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 – Chronic repositioning or
removal of leads may be difficult because of fibrotic tissue
development. Studies have not specifically evaluated the removal
of left ventricular leads from the coronary venous vasculature. If a
lead must be removed or repositioned, proceed with extreme
caution. Return all removed leads to Medtronic.
●
Verify lead length on the IS-1 label on the connector to choose
an appropriate stylet kit (downsized knob) length when
repositioning. Always choose a stylet kit (downsized knob)
3 cm shorter than the lead length listed on the IS-1 connector
label. For example, choose a stylet kit (downsized knob) with
stylets 75 cm long for a lead 78 cm long.
●
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 a steroid
eluting lead’s low-threshold performance.
●
Cap abandoned leads to avoid transmitting electrical signals.
●
For leads that have been severed, seal the remaining lead
end and suture the lead to adjacent tissue.
●
If a lead is removed and repositioned, inspect it carefully for
insulator or conductor coil damage prior to repositioning.
6 Potential adverse events
The potential adverse events (listed in alphabetical order) related
to the use of transvenous leads include, but are not limited to, the
following conditions:
Additional potential adverse events related to the lead and the
programmed parameters include, but are not limited to, the
following:
Potential adverse
event
Lead dislodgementaIntermittent or contin-
Lead dislodgementaIntermittent or contin-
Indicator of potential adverse event
uous loss of capture
or sensing
a
uous oversensing
Corrective action to
be considered
Reposition the lead.
Reposition the lead.
5
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Potential adverse
event
Lead conductor fracture or insulation failure
Threshold elevation
or exit block
a
Transient loss of capture or sensing may occur following surgery until
lead stabilization takes place. If stabilization does not occur, lead
dislodgement may be suspected.
Indicator of potential adverse event
Intermittent or continuous loss of capture
or sensing
Loss of capture
a
a
Corrective action to
be considered
Replace the lead.
Adjust the implantable device output.
Replace or reposition
the lead.
Implant techniques that may damage the lead include, but are not
limited to, the following:
Implant techniques
that may damage
the lead
Forcing the lead
through the introducer/delivery system
Use of too medial of
an approach with
venous introducer
resulting in clavicle &
first rib binding
Puncturing the periosteum and/or tendon
when using subclavian introducer
approach
Advancing the lead
through the veins
without the stylet or
guide wire fully inserted
Inserting the proximal
end of the guide wire
through the lead tip
seal without using the
guide wire insertion
tool
Advancing a stylet tip
beyond the distal end
of the lead tip seal
7.1 Attain Bipolar OTW Model 4194 left-heart lead
study
A prospective, multi-center trial conducted at 22 investigative
sites in the United States and Canada evaluated the safety and
effectiveness of the Medtronic Attain Bipolar OTW Model 4194
left-heart lead in heart failure patients.
An investigational protocol pre-specified the performance criteria
for both safety and effectiveness based on previous studies. For
this study, patients who satisfied inclusion and exclusion criteria
underwent a baseline evaluation to determine study eligibility and
then underwent a cardiac resynchronization system implant
attempt, which could include the Model 4194 left heart lead.
Key study inclusion criteria included patients with the following:
●
Patient provides written informed consent
●
Patients 18 years of age or older
●
Patient is diagnosed with New York Heart Association
functional classification three (NYHA III) or New York Heart
Association functional classification four (NYHA IV) despite
optimal medical therapy which is defined as:
– ACE inhibitor or Angiotensin Receptor Blocker (ARB), if
tolerated, for at least 1 month prior to implant
– Beta-blockers for at least 3 months preceding implant, if
tolerated, and stable for 1 month. Stable is defined as no
upward titration of beta-blockers.
●
Demonstrated intrinsic QRS duration ≥ 130 ms (test
documented within 6 months of baseline)
●
Left ventricular ejection fraction (EF) ≤ 35% (test documented
within 12 months of baseline)
●
Patient is expected to remain available for follow-up visits
●
Patient is willing and able to comply with the protocol
●
Patient is indicated for ICD implantation for the treatment of
life threatening ventricular arrhythmias (required only if a
patient will receive an ICD)
Key study exclusion criteria included patients with the following:
●
Patients with a previous complete atrial based biventricular
CRT system
●
Patients with a previous LV lead implanted or previous
implant attempt within 30 days of implant or ongoing adverse
events from previous unsuccessful attempt
●
Patients contraindicated for < 1.0 mg dexamethasone sodium
phosphate
●
Patients with unstable angina or who have experienced an
acute myocardial infarction (MI) within the past month
●
Patients who have had a coronary artery revascularization
(CABG) or coronary angioplasty (PTCA) within the past 3
months
●
Patients on more than 2 inotropic infusions per week within 1
month of implant
●
Patients with contraindications for standard transvenous
cardiac pacing (for example, mechanical right heart valves)
●
Patients with chronic (permanent) atrial arrhythmias
●
Post heart transplant patients (patients waiting for heart
transplant are allowed in the study)
●
Patients enrolled in any concurrent drug and/or device study
that may confound the results of this study
●
Patients with a terminal illness who are not expected to
survive more than 6 months
6
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●
Implant attempted (incision made)
Model 4194 lead implant NOT attempted Model 4194 lead implant attempted
No LV lead implanted
Model 4194 lead
successfully
implanted
Three-month
follow-ups
Model 4193 lead
successfully
implanted
Model 4193 lead successfully
implanted
Competitor (not
Medtronic) LV lead
successfully
implanted
No LV lead
implanted
201
1956
5
5
190
2
162
95
10112
3
185
Successful CS cannulation
Unsuccessful CS cannulation
Implant not attempted
Patients enrolled (informed consent form signed)
Women who are pregnant, or have a positive pregnancy test
within 7 days of implant, or with child bearing potential and
who are not on a reliable form of birth control (all women of
child bearing potential must undergo a pregnancy test within
7 days of implant)
●
Patients unable to tolerate an urgent thoracotomy
Patients successfully implanted with a Model 4194 lead were
followed at pre-hospital discharge (PHD), 1 month, 3 months, 6
months and every 6 months thereafter. Patients attempted with a
Model 4194 lead who did not ultimately have a successful Model
4194 implant were followed for 1 month or until all relevant
adverse events were resolved.
All patients who underwent a Model 4194 lead attempt were
included in the analysis of the safety results. Those patients who
were successfully implanted with a Model 4194 lead were
included in the analysis of the efficacy results. Of the 201 patients
who were enrolled in the study, 195 underwent a cardiac
resynchronization implant attempt. One hundred sixtytwo (162) of
those patients were successfully implanted with a Model 4194
lead and 13 patients were successfully implanted with a Model
4193 lead, resulting in an OTW lead success rate of 89.7%.
Ninety-five (95) of the Model 4194 lead patients have completed
the 3-month follow-up visit. Figure 1 illustrates an overview of
patient accountability and disposition at the time of data analysis.
Table 1 summarizes the reasons for unsuccessful Model 4194
lead implants.
Figure 1. Implant status for the 201 patients enrolled in the study
Table 1. Reasons for unsuccessful Model 4194 implant attempts
(N = 23)
ReasonN
Unacceptable pacing thresholds6
Coronary vein too small6
Unable to obtain adequate distal location5
Diaphragmatic stimulation5
Unable to access coronary vein4
Dislodgement/unstable location2
Unable to negotiate curve1
a
Categories are not mutually exclusive.
a
7.1.1 Objectives
There were 2 primary study objectives and 4 secondary
objectives for the Model 4194 lead clinical study. Pre-established
performance criteria for each of the primary objectives were
documented in the protocol prior to study start. The secondary
objectives were descriptive in nature and were designed to obtain
additional information about the Model 4194 lead.
Primary objective – Evaluate the complication-free survival from
lead-related complications at 3 months.
Results:
– Observed survival from Model 4194 lead-related
complications: 96.3%
– Lower limit of 1-sided 95% confidence interval at 3 months:
89.7%
– Objective met.
There were 8 Model 4194 lead-related complications in 8
patients, all of which resolved. Six (6) of these complications had
occurred by 3 months. All 8 are summarized in Table 2.
Table 2. Model 4194 lead-related complications and treatments
Complication event/treatmentN
Lead dislodgement
Lead repositioned4
a
Lead replaced with Model 4193 lead2
Elevated pacing threshold
Lead repositioned1
Diaphragmatic muscle stimulation
Lead replaced with Model 4193 lead1
Total8
a
Two (2) of the lead dislodgements treated by repositioning occurred after
the 3-month time point.
Primary objective – Evaluate the mean bipolar voltage threshold
for the Model 4194 lead at 3 months.
●
Performance criteria: Upper 95% confidence limit ≤ 2.5 V.
7
Page 8
●
1.41
1.62
1.49
1.59
1.51
0
0.5
1
1.5
2
2.5
3
3.5
Implant
(N=162)
PHD
(N=159)
1 Month
(N=149)
3 Month
(N=93)
6 Month
(N=23)
Visit
Threshold @ 0.5 ms (V)
13.86
12.40
13.93
16.00
14.19
0
5
10
15
20
25
Implant
(N=162)
PHD
(N=153)
1 Month
(N=141)
3 Month
(N=89)
6 Month
(N=23)
Visit
R-Wave Amplitude (mV)
963.7
752.5
718.7
793.0
745.9
0
200
400
600
800
1000
1200
1400
Implant
(N=162)
PHD
(N=141)
1 Month
(N=131)
3 Month
(N=82)
6 Month
(N=18)
Visit
Impedance (Ohms)
Results:
– Mean bipolar voltage threshold (@ 0.5 ms) at 3 months:
1.5 V ± 1.05
– Upper limit of 1-sided 95% confidence interval: 1.68 V
– Objective met.
Figure 2. Model 4194 lead bipolar threshold data at 0.5 ms (mean
± one standard deviation)
Table 4. Model 4194 lead implant times (minutes)
NMeanStd. Dev.Range
Cannulation time1628.913.3<1.0 - 90.0
Fluoroscopy time16124.015.85.1 - 101.0
Model 4194 lead
16212.011.81.0 - 100.0
placement time
Total implant time161117.158.439.0 - 380.0
Secondary objective – To evaluate the electrical performance
(sensing, impedance, phrenic nerve stimulation, and atrial anodal
stimulation) of the Model 4194 lead.
There was no anodal stimulation reported at the Pre-Hospital
Discharge and one instance (2.4%) at the 3-month follow-up visit
(5.0 V). Overall, electrical measurements were within expected
ranges and stable over time. Figure 3 and Figure 4 illustrate the
Model 4194 lead R-wave amplitude and impedance over time.
Figure 3. Model 4194 lead R-wave amplitude (mean ± one
standard deviation)
Secondary objective –
●
The overall Attain lead family
●
The Attain lead family after successful coronary sinus
cannulation
●
The Model 4194 lead
To evaluate the implant success rates of:
The overall Attain lead family implant success rate was 89.7%.
The Attain lead family success after successful coronary sinus
cannulation was 93.1%. The overall Model 4194 implant success
rate was 87.6%. These rates are presented in Table 3.
Table 3. Lead implant success rates
Lead Group
implants
Attain lead family19517589.
Attempted
Attain lead family after cannula-
188
tion
Model 4194 lead18516287.
a
This number includes all patients who were successfully cannulated less
the 2 patients who were cannulated but had no lead attempts.
Secondary objective – To evaluate the total implant,
fluoroscopy, cannulation, and LV placement time for the Model
4194 lead.
Table 4 summarizes the implant-related times for successful
Model 4194 lead implants. Cannulation time, fluoroscopy time,
lead placement time, and total implant time were all within
expected ranges.
8
a
Successful
implants
17593.
Su
cce
ss
rat
7%
1%
6%
Figure 4. Model 4194 lead impedance (mean ± one standard
deviation)
e
Table 5 summarizes the phrenic nerve stimulation observed at
implant. Five (5) patients experienced phrenic nerve stimulation in
all 3 configurations. An additional 6 patients experienced phrenic
nerve stimulation at 1 of the 3 configurations (2 patients at each).
Page 9
Table 5. Model 4194 Phrenic nerve stimulation at implant (volts)
Per-
UTC
N MeanStd DevRange
Unipolar75.902.492.20 -
LV tip / LV
anode
LV tip / RV
anode
76.242.522.30 -
76.812.723.20 -
10.0
10.0
10.0
cent
(N)
(%)
15295.6%
15595.7%
15495.7%
Secondary objective – To evaluate all adverse events occurring
during the clinical study (excluding unavoidable adverse events).
A total of 224 adverse events in 107 patients were reported in this
patient cohort. Seventy-nine (79) of the events (in 53 patients)
were classified as complications and 145 (in 79 patients) were
classified as observations. A complication was defined as an
adverse event which was resolved invasively or which directly
resulted in the death of or serious injury to the patient, or the
termination of significant device function regardless of other
treatments. An observation was defined as an adverse event
which was resolved by non-invasive means such as medically or
by reprogramming the device or which resolved spontaneously.
Table 6 provides an overview of all the adverse events.
Table 6. Summary of all adverse events
RelatednessComplicationsObservations
Model 4194 left ventricular lead
Right atrial lead70
Right ventricular lead01
Cardiac resynchronization device
Cardiac resynchronization system
Implant tool74
Procedure1630
Unrelated to cardiac
resynchronization system
Total79145
816
08
01
4185
The Model 4194 lead-related adverse events are presented in
Table 7. Complications related to the Model 4194 lead included
lead dislodgements, diaphragmatic muscle stimulation, and an
elevated pacing threshold.
Table 7. Model 4194 lead-related adverse events
Event
Muscle stimulation - diaphragm
Lead dislodgement606
Compli-
cations
Observa-
tions
11313
Total number
of patients
Table 7. Model 4194 lead-related adverse events (continued)
Event
Elevated pacing threshold123
Muscle stimulation - pectoral
Total81622
a
Note: The 24 events occurred in 22 patients.
Compli-
cations
Observa-
tions
011
Total number
of patients
a
Table X summarizes the implant tool-related adverse events.
Table 8. Implant tool-related adverse events
Event
Coronary sinus dissection336
Coronary sinus perforation112
Air embolism101
Cardiac perforation101
Ventricular tachycardia101
Total7410
a
Note: The 11 events occurred in 10 patients.
Compli-
cations
Observa-
tions
Total number
of patients
a
7.2 InSync Registry study
The InSync Registry clinical study document is available at
www.medtronic.com/manuals. The following is a synopsis of the
study:
InSync Registry condition-of-approval clinical study – This
observational study was required as a condition of approval for
the InSync Model 8040 and InSync III Model 8042 devices, the
Attain LV lead models 2187 and 2188, and the Attain OTW
models 4193 and 4194 left ventricular leads. The findings of the
InSync Registry condition-of-approval clinical study demonstrate
that the InSync and InSync III systems with Attain LV lead models
2187, 2188, and OTW lead models 4193 and 4194, are safe and
effective as part of a cardiac resynchronization therapy (CRT)
system.
8 Directions for use
Warning: Do not force the guide catheter or lead if significant
resistance is encountered. Use of guide catheters or leads may
cause trauma to the heart.
Note: To implant the Model 4194 lead in a cardiac vein, a
compatible delivery system is required, such as a Medtronic
delivery system. A compatible delivery system includes a guide
catheter and a hemostasis valve or introducer valve which allows
passage through or removal from an IS-1 connector. Contact a
Medtronic representative for further information regarding
compatible delivery systems.
9
Page 10
Proper surgical procedures and sterile techniques are the
1
responsibility of the medical professional. The implant
procedures described in this manual are provided for information
only. Each physician must apply the information in these
instructions according to professional medical training and
experience.
The implant procedure generally includes the following steps:
●
Placing the right ventricular lead
●
Preparing the delivery system
●
Accessing the subclavian vein
●
Inserting the guide catheter assembly
●
Obtaining venograms
●
Inserting the lead into the delivery system
●
Selecting the lead placement method
●
Placing the lead using a stylet
●
Preparing the guide wire
●
Placing the lead using a guide wire
●
Fixating the lead
●
Taking electrical measurements
●
Removing the guide catheter from the lead
●
Anchoring the lead
●
Connecting the lead
●
Placing the device and leads into the pocket
8.1 Placing the right ventricular lead
Note: When deciding which ventricular lead to place first,
consider the ease of coronary sinus cannulation and the need for
backup pacing.
●
When a left ventricular lead is implanted first:
– It may be easier to cannulate the coronary sinus without
other leads already implanted.
– Additional hospital equipment may be necessary to
provide backup pacing.
●
When a right ventricular lead is implanted first:
– A right ventricular lead may be used to provide backup
pacing.
– It may be more difficult to cannulate the coronary sinus with
a right ventricular lead already implanted.
8.2 Preparing the delivery system
Prepare the delivery system for lead implantation according to the
instructions in the product literature packaged with the delivery
system.
8.3 Accessing the subclavian vein
Access the subclavian vein:
1. Use a preferred method, based on professional experience,
to access the subclavian vein.
Caution: Certain anatomical abnormalities, such as thoracic
outlet syndrome, may precipitate pinching and subsequent
fracture of the lead.
Caution: Insertion should be done 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
2. Introduce a J-shaped introducer guide wire and
percutaneous introducer sheath.
8.4 Inserting the guide catheter assembly
Warning – Back-up pacing should be readily available during
implant. Use of the delivery system or leads may cause heart
block.
Access the coronary sinus:
1. Insert the guide catheter assembly.
2. Advance the guide catheter to the right atrium.
3. Achieve entry into the coronary sinus by rotating the guide
catheter tip posteriorly and to the patient’s left.
See the delivery system product documentation for additional
information.
8.5 Obtaining venograms
Before placing a lead in the coronary sinus, obtain venograms.
Venograms are recommended to assess a route for passage and
a site for final placement based on the size, shape, location, and
tortuosity of the veins. Also, venograms may be useful in
identifying suspected coronary sinus trauma. For information on
obtaining a venogram by using a venogram balloon catheter, see
the product documentation packaged with an appropriate
venogram balloon catheter.
8.6 Inserting the lead into the delivery system
Warning: Use only the stylets packaged with the lead or in a stylet
kit (downsized knob). Other stylets may extend beyond the lead
tip causing lead tip seal damage and/or patient injury.
Warning: Do not force the lead if significant resistance is
encountered during lead passage.
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
pin.
Insert the lead:
1. Remove and discard the stylet packaged with the lead.
2. Insert a straight stylet into the lead to vary the shape of the
lead’s distal end.(Figure 6).
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Note: When the stylet is fully inserted, the distal tip of the
1
2
1
2
stylet does not reach the distal tip of the lead (Figure 6).
Figure 6.
1 Stylet fully withdrawn
2 Stylet fully inserted
3. Insert the lead into the delivery system. See the delivery
system product documentation for additional information.
8.7 Selecting the lead placement method
The Model 4194 lead can be placed with the aid of a stylet or with
a guide wire.
To determine the placement method, review the venogram to
determine if stylet or guide wire delivery should be used.
Stylet delivery – If the patient’s anatomy features gentle vein
angulation off of the coronary sinus and the cardiac vein branch is
not tortuous (Figure 7), use a stylet for lead delivery. See
Section 8.8 for more information.
Figure 7.
Figure 8.
1 Tortuous cardiac vein branch with gentle angulation from the
coronary sinus
2 Tortuous cardiac vein branch with acute angulation from the coronary
sinus
8.8 Placing the lead using a stylet
Warning: Do not force the lead if significant resistance is
encountered during lead passage.
Warning: To minimize the likelihood of trauma to the vein and to
maintain lead flexibility while advancing the lead through the vein,
keep the stylet withdrawn 1 to 2 cm or select a more flexible stylet.
Caution: To avoid damage to the stylet, do not use a sharp object
to impart a curve at the distal end of a stylet (Figure 9).
Figure 9.
1 Coronary sinus
2 Cardiac vein
Guide wire delivery – If the patient’s anatomy features acute
vein angulation off of the coronary sinus and the cardiac vein
branch is tortuous (Figure 8), use a guide wire for lead delivery.
See Section 8.9 for more information.
Note: If it is difficult to advance the stylet around a bend, consider
changing the stylet. More flexible stylets are recommended for
tortuous anatomies. Firmer stylets are recommended where
additional support is needed.
There are 2 techniques that may be used to advance the lead into
a cardiac vein. The choice of technique is left to the discretion of
the physician.
8.8.1 First technique to advance the lead into a cardiac vein
using a stylet
Advance the lead into a cardiac vein:
1. Advance the lead up to, but not past, the cardiac vein ostium
(Figure 10).
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Figure 10.
2. Use 1 or more of the following actions to direct the lead tip
into the cardiac vein:
●
Withdraw the stylet
●
Advance the lead off of the stylet
●
Remove the straight stylet. Manually shape the stylet
into a curve. Insert the curved stylet into the lead. Rotate
the lead body and stylet together.
●
Rotate the lead’s curved tip into the cardiac vein.
3. Advance the lead into the cardiac vein (Figure 11).
Figure 11.
4. Advance the lead, with the stylet inserted, further into the
cardiac vein. See Section 8.11, “Fixating the lead”, page 14
for additional information.
Note: The anode should be placed in the selected vein, not
in the coronary sinus.
8.8.2 Second technique to advance the lead into a cardiac
vein using a stylet
Advance the lead into a cardiac vein:
1. Advance the lead past the ostium of the cardiac vein
(Figure 12).
Figure 12.
2. Refer to 1 of the following procedures according to the type
of stylet used.
●
Straight stylet: If using a straight stylet, withdraw the
stylet 1 to 2 cm and rotate the lead to align the curved
lead tip with the cardiac vein ostium.
●
Curved stylet: If using a curved stylet, withdraw the
stylet 1 to 2 cm and rotate the stylet and lead body
together to align the curved lead tip with the cardiac vein
ostium.
3. Withdraw the lead and drag the curved lead tip over the
ostium of the cardiac vein until the lead turns into the vein.
Reinsert the stylet slightly to advance the lead into the
cardiac vein (Figure 13).
Figure 13.
4. Advance the lead, with the stylet inserted, further into the
cardiac vein. See Section 8.11, “Fixating the lead”, page 14
for additional information.
Note: The anode should be placed in the selected vein, not
in the coronary sinus.
8.9 Preparing the guide wire
Warning: Damage to a guide wire may prevent the guide wire
from performing with accurate torque response and control and
may cause vessel damage. For additional information about
vessel damage and other potential adverse events, refer to the
technical manual packaged with the appropriate guide product.
Caution: Use care when positioning the guide wire. Refer to the
product documentation packaged with the guide wire for
additional information.
Note: Medtronic recommends using guide wires 0.36 mm to
0.46 mm (0.014 in to 0.018 in) in diameter. Contact a Medtronic
representative for further information about recommended guide
wires.
Prepare the guide wire for use:
1. Select a guide wire. A more flexible guide wire is
recommended if the patient has tortuous anatomy. If
additional support is needed, use a firmer guide wire.
Note: Guide wire firmness is determined by 2 factors: guide
wire diameter and guide wire core design. A larger guide wire
diameter may be firmer than a smaller guide wire diameter.
However, guide wires with the same diameter may have
different degrees of firmness. A “J” shaped guide wire or
angled tip guide wire are recommended to aid in
sub-selecting the cardiac vein and where more steerability is
desired.
Note: Consider soaking the guide wire in a heparin solution
prior to insertion to minimize the risk of thrombus formation
during use.
2. Remove the stylet.
3. Insert the guide wire into the lead by placing the distal
(flexible) end of the guide wire into the lead connector pin
using the guide wire insertion tool included in the package
(Figure 14).
Caution: To minimize the risk of damaging the guide wire, be
sure the flexible section of the guide wire is fully inserted into
the lead before removing the guide wire insertion tool from
the lead.
12
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Figure 14.
4. Disengage the guide wire insertion tool from the lead
connector pin.
5. Remove the guide wire insertion tool using the slit on the tool
or by sliding the tool off the end of the guide wire.
6. Position the guide wire steering handle (Figure 15) :
a. Advance the guide wire steering handle over the
proximal (rigid) end of the guide wire.
b. Tighten the guide wire steering handle onto the guide
wire near the lead connector pin.
Figure 15.
1 Guide wire steering handle
2 Lead connector pin
7. Attach the guide wire clip to the guide wire and secure it
within the sterile field. Medtronic recommends securing the
guide wire clip to the patient’s sterile surgical drape.
Alternate approach: In situations where the guide wire is already
in place, the lead can be loaded over the guide wire using the
guide wire insertion tool.
Insert the guide wire into the lead by placing the proximal (rigid)
end of the guide wire into the distal lead tip using the guide wire
insertion tool included in the package (Figure 16).
Note: There may be slight resistance as the guide wire passes
through the lead tip seal.
Note: Be sure to remove the guide wire insertion tool prior to lead
implant.
Figure 16.
8.10 Placing the lead using a guide wire
Warning: Do not force the lead if significant resistance is
encountered during lead passage.
Caution: If the guide wire’s distal end becomes severely kinked or
twisted, it may be difficult to withdraw it back through the lead.
Therefore, if there is an indication that guide wire’s distal end has
become damaged, or if there is a lot resistance in guide wire
passage, remove the lead and guide wire. Remove the guide wire
from the lead and insert a new guide wire into the lead. Do not use
excessive force to retract the guide wire from the lead.
Note: If the lead is not advancing, or if the lead and guide wire
seem to be sticking together, there may be thrombus on the guide
wire at the lead tip. Remove and inspect the lead and guide wire.
Consider using a new guide wire. Reinsert the lead and the guide
wire as described in previous steps.
Note: If it is difficult to advance the guide wire around a bend,
consider changing the guide wire. More flexible guide wires are
recommended for tortuous anatomies. Firmer guide wires are
recommended where additional support is needed.
There are 2 techniques that may be used to advance the lead into
a cardiac vein. The choice of technique is left to the discretion of
the physician.
8.10.1 First technique to advance the lead into a cardiac
vein using a guide wire
Advance the lead into a cardiac vein:
1. Using venogram images as reference, advance the lead into
the coronary sinus. Keep the distal tip of the guide wire
beyond the distal tip of the lead during passage and
placement (Figure 17).
Figure 17.
2. Rotate the guide wire and advance the guide wire into the
cardiac vein. Pass the lead over the guide wire and into the
cardiac vein (Figure 18).
Figure 18.
3. Advance the lead further into the cardiac vein by advancing
the lead along the guide wire or by advancing the lead and
guide wire together. See Section 8.11, “Fixating the lead”,
page 14 for additional information.
Note: The anode should be placed in the selected vein, not
in the coronary sinus.
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Page 14
8.10.2 Second technique to advance the lead into a cardiac
vein using a guide wire
Advance the lead into a cardiac vein:
1. Using venogram images as reference, advance the lead into
the cardiac vein (Figure 19). The lead’s curved distal tip may
be used to aid in subselecting cardiac veins within the
coronary sinus by slightly retracting the guide wire inside the
lead lumen.
Figure 19.
2. If retracted, reinsert the guide wire through the lead tip seal
and more distally into the cardiac vein. Advance the lead
over the guide wire into the cardiac vein (Figure 20).
Figure 20.
3. Advance the lead further into the cardiac vein by advancing
the lead along the guide wire or by advancing the lead and
guide wire together. See Section 8.11, “Fixating the lead”,
page 14 for additional information.
Note: The anode should be placed in the selected vein, not
in the coronary sinus.
8.11 Fixating the lead
Fixation is achieved the same way regardless of whether a stylet
or a guide wire is used.
Fixate the lead:
Using fluoroscopy for guidance, fixate the lead by wedging both
curves of the lead tip into the cardiac vein (Figure 21).
Figure 21.
Note: If the cardiac vein is large, it may be necessary to position
the lead in a smaller cardiac vein in order to achieve lead tip
fixation.
8.12 Taking electrical measurements
Caution: Prior to taking electrical or defibrillation efficacy
measurements, move objects made of conductive materials,
such as guide wires or stylets, away from all electrodes.
Note: For the Model 4194 initial electrical measurements should
be taken with the stylet or guide wire retracted a minimum of 4 cm
inside the lead lumen.
Take electrical measurements:
1. Attach a surgical cable to the lead connector pin.
Note: A unipolar lead requires the use of an indifferent
electrode.
2. Use an implant support instrument, such as a pacing system
analyzer, for obtaining electrical measurements (Table 9).
For information on the use of the implant support instrument,
consult the product documentation for that device.
Satisfactory lead placement is indicated by low stimulation
thresholds and adequate sensing of intracardiac signal
amplitudes.
●
A low stimulation threshold provides a desirable safety
margin, allowing for a possible rise in thresholds that
may occur within 2 months following implant.
●
Adequate sensing amplitudes ensure that the lead is
properly sensing intrinsic cardiac signals. Minimum
signal requirements depend on the sensitivity
capabilities of the device. Acceptable acute signal
amplitudes for the lead must be greater than the
minimum device sensing capabilities. Be sure to include
an adequate safety margin to account for lead maturity.
Table 9. Recommended measurements at implant (Assumes
500 Ω resistance)
Measurement recommendedLeft ventricle
Maximum acute stimulation thresholdsa3.0 V
Minimum acute sensing amplitudes4.0 mV
a
At a pulse duration setting of 0.5 ms.
3. If electrical measurements do not stabilize to acceptable
levels, it may be necessary to reposition the lead and repeat
the testing procedure.
4. Check for diaphragmatic stimulation by pacing at 10 V and a
pulse width setting greater than 0.5 ms. Then observe for
diaphragmatic contracting either by fluoroscopy or direct
abdominal palpitation. Further testing may include patient
positional changes to simulate upright chronic conditions. If
diaphragmatic pacing occurs, reduce the voltage until a
diaphragmatic pacing threshold is determined.
Diaphragmatic stimulation usually necessitates
repositioning of the lead.
14
Page 15
8.13 Removing the guide catheter from the lead
Once the lead is in the final position, perform the following steps:
1. If used, remove the guide wire and replace the guide wire
with a straight stylet (downsized knob). Insert the straight
stylet into the lead to the mid-coronary sinus.
2. Remove the guide catheter from the lead. See the delivery
system product documentation for details.
3. Carefully and completely remove the stylet. When removing
the stylet, grip the lead firmly just below the connector pin;
this will help prevent possible lead tip dislodgement.
4. Repeat the electrical measurements. See Section 8.12,
“Taking electrical measurements”, page 14.
8.14 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.
●
Do not use the anchoring sleeve tabs for suturing.
●
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 22).
●
Do not tie a suture directly to the lead body (Figure 22).
Figure 22.
Anchor the lead using all 3 grooves:
1. Position the 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 23).
Figure 23.
1. Take final electrical measurements.
2. Insert the lead connector into the connector block. Consult
the product documentation packaged with the implantable
device for instructions on proper lead connections.
8.16 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 24).
Figure 24.
Place the device and leads into the pocket:
1. Rotate the device to loosely wrap the excess lead length.
Caution: To prevent undesirable twisting of the lead body,
wrap the excess lead length loosely under the implantable
device and place both into the subcutaneous pocket
(Figure 25).
Figure 25.
2. Suture the pocket closed using a preferred surgical
technique.
8.17 Post-implant evaluation
3. Use at least 1 additional suture in 1 of the grooves to secure
the anchoring sleeve and lead body to the fascia.
8.15 Connecting the lead
Caution: Always remove the stylet and stylet guide before
connecting the lead to the device. Failure to remove the stylet may
result in lead failure.
Connect the lead to an implantable device.
After implant, monitor the patient’s electrocardiogram until the
patient is discharged. If a lead dislodges, it usually occurs during
the immediate postoperative period.
9 Detailed device description
9.1 Specifications (nominal)
ParameterModel 4194
TypeBipolar
Chamber pacedVentricle
Length20–100 cm
15
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ParameterModel 4194
ConnectorIS-1 BI
MaterialsConductors: MP35N
Insulators: Polyurethane (outer)
Silicone (inner)
Electrode tip: Platinum alloy
Anode coil: Platinum alloy
Connector pin: Stainless steel
Connector
Stainless steel
ring:
Molded tip
Silicone rubber
seal:
Tip electrode configurationTapered annular, plati-
nized
DiameterLead body: 6 French (2.0 mm)
Tip electrode: 5.4 French (1.8 mm)
Medtronic delivery sys-
7 French (2.3 mm)
tem (recommended
inner diameter)
Diagnostic guide wire
(recommended diame-
0.36 mm to 0.46 mm
(0.014 in to 0.018 in)
ter)
Tip electrode surface
5.8 mm
2
area
Anode coil surface area38 mm
2
ResistanceUnipolar: 67 Ω at 78 cm
Bipolar: 126 Ω at 78 cm
Distance between elec-
11 mm
trodes
SteroidDexamethasone sodium
phosphate
Amount of steroid1.0 mg maximum
9.2 Specifications drawing
Figure 26.
16
1 Anode coil diameter: 5.4 French (1.8 mm); surface area 38 mm
2
2 Tip electrode diameter: 5.4 French (1.8 mm); surface area 5.8 mm
3 Anchoring sleeve
4 Total lead length: 20-110 cm
5 IS-1 BI connector
2
Page 17
10 Medtronic warranty
For complete warranty information, see the accompanying
warranty document.
11 Service
Medtronic employs highly trained representatives and engineers
located throughout the world to serve you and, upon request, to
provide training to qualified hospital personnel in the use of
Medtronic products. Medtronic also maintains a professional staff
to provide technical consultation to product users. For more
information, contact your local Medtronic representative, or call or
write Medtronic at the appropriate telephone number or address
listed on the back cover.
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