U.S. patent application number 10/117483 was filed with the patent office on 2002-08-15 for low profile, ventricular, transvenous, epicardial defibrillation lead.
This patent application is currently assigned to Cardiac Pacemakers, Inc.. Invention is credited to Bartig, Jeffrey T., Chastain, Stuart R., Crevensten, Gwen, Heil, John E., Jahnke, Aaron W., Lindstrom, Curtis C..
Application Number | 20020111664 10/117483 |
Document ID | / |
Family ID | 23611734 |
Filed Date | 2002-08-15 |
United States Patent
Application |
20020111664 |
Kind Code |
A1 |
Bartig, Jeffrey T. ; et
al. |
August 15, 2002 |
Low profile, ventricular, transvenous, epicardial defibrillation
lead
Abstract
A cardiac lead designed for implantation in the vasculature of
the left side of the heart comprising a flexible lead body having a
central lumen, a removable terminal pin, electrodes electrically
coupled to the removable terminal pin, a mechanism for securing the
electrodes in the proper position in the vasculature and a
mechanism for sealing the central lumen after implantation to
prevent body fluids from invading the lumen. The cardiac lead can
be implanted or explanted using either a guidewire, a guide
catheter or both.
Inventors: |
Bartig, Jeffrey T.;
(Maplewood, MN) ; Chastain, Stuart R.; (Shoreview,
MN) ; Crevensten, Gwen; (Minneapolis, MN) ;
Heil, John E.; (White Bear Lake, MN) ; Lindstrom,
Curtis C.; (Roseville, MN) ; Jahnke, Aaron W.;
(Houston, TX) |
Correspondence
Address: |
NIKOLAI MERSEREAU & DIETZ, P.A.
820 INTERNATIONAL CENTRE
900 SECOND AVENUE SOUTH
MINNEAPOLIS
MN
55402
|
Assignee: |
Cardiac Pacemakers, Inc.
St. Paul
MN
|
Family ID: |
23611734 |
Appl. No.: |
10/117483 |
Filed: |
April 5, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10117483 |
Apr 5, 2002 |
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09407364 |
Sep 29, 1999 |
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6408213 |
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Current U.S.
Class: |
607/122 |
Current CPC
Class: |
A61N 1/0563 20130101;
A61N 2001/0585 20130101 |
Class at
Publication: |
607/122 |
International
Class: |
A61N 001/05 |
Claims
What is claimed is:
1. For use with a cardiac rhythm management device, a low profile,
ventricular, transvenous, epicardial lead having: (a) an elongated,
flexible body member made of an electrically insulative material,
said body member having a proximal section, a distal section, an
outer wall extending the length of the body member, an opening
through said outer wall in said distal section and a lumen
extending from said opening through said outer wall, said proximal
section being stiffer than the distal section, said proximal
section possessing adequate axial stiffness and said distal section
being sized and sufficiently flexible to permit the distal section
to be advanced through the right atrium and coronary sinus into the
coronary vein; (b) an electrode capable of delivering
defibrillating pulses to the left ventricle of the heart and
coupled to the distal section of said body member, said electrode
comprising a soft, flexible material doped with conductive
particles and being of a size and flexibility to be advanced along
with the distal section of the body member through the right atrium
and coronary sinus into the coronary veins to a location adjacent
the wall of the left ventricle; (c) a terminal pin; (d) a
conductive member extending within said body member from said
electrode for providing an electrical path between said electrode
and said terminal pin; (e) means for retaining said electrode in
the coronary vein; and (f) means for sealing said opening through
the outer wall of said body member.
2. For use with a cardiac rhythm management device, a low profile,
ventricular, transvenous, epicardial lead having: (a) an elongated,
flexible body member made of an electrically insulative material,
said body member having a proximal section, a distal section, an
outer wall extending the length of the body member, an opening
through said outer wall in said distal section and a lumen
extending from said opening through said outer wall, said proximal
section being stiffer than the distal section, said proximal
section possessing adequate axial stiffness and said distal section
being sized and sufficiently flexible to permit the distal section
to be advanced through the right atrium and coronary sinus into the
coronary vein; (b) an electrode capable of delivering
defibrillating pulses to the left ventricle of the heart and
coupled to the distal section of said body member, said electrode
comprising a braided wire screen and being of a size and
flexibility to be advanced along with the distal section of the
body member through the right atrium and coronary sinus into the
coronary veins to a location adjacent the wall of the left
ventricle; (c) a terminal pin; (d) a conductive member extending
within said body member from said electrode for providing an
electrical path between said electrode and said terminal pin; (e)
means for retaining said electrode in the coronary vein; and (f)
means for sealing said opening through the outer wall of said body
member.
3. For use with a cardiac rhythm management device, a low profile,
ventricular, transvenous, epicardial lead having: (a) an elongated,
flexible body member made of an electrically insulative material,
said body member having a proximal section, a distal section, an
outer wall extending the length of the body member, an opening
through said outer wall in said distal section and a lumen
extending from said opening through said outer wall, said proximal
section being stiffer than the distal section, said proximal
section possessing adequate axial stiffness and said distal section
being sized and sufficiently flexible to permit the distal section
to be advanced through the right atrium and coronary sinus into the
coronary vein; (b) an electrode capable of delivering
defibrillating pulses to the left ventricle of the heart and
coupled to the distal section of said body member, said electrode
comprising a plurality of small ring spaces of a soft, flexible
material and being of a size and flexibility to be advanced along
with the distal section of the body member through the right atrium
and coronary sinus into the coronary veins to a location adjacent
the wall of the left ventricle; (c) a terminal pin; (d) a
conductive member extending within said body member from said
electrode for providing an electrical path between said electrode
and said terminal pin; (e) means for retaining said electrode in
the coronary vein; and (f) means for sealing said opening through
the outer wall of said body member.
4. For use with a cardiac rhythm management device, a low profile,
ventricular, transvenous, epicardial lead having: (a) an elongated,
flexible body member made of an electrically insulative material,
said body member having a proximal section, a distal section, an
outer wall extending the length of the body member, said outer wall
having at least one area incorporating microtexturing to permit
fibrotic attachment to the wall of the coronary vein, an opening
through said outer wall in said distal section and a lumen
extending from said opening through said outer wall, said proximal
section being stiffer than the distal section, said proximal
section possessing adequate axial stiffness and said distal section
being sized and sufficiently flexible to permit the distal section
to be advanced through the right atrium and coronary sinus into the
coronary vein; (b) an electrode capable of delivering
defibrillating pulses to the left ventricle of the heart and
coupled to the distal section of said body member, said electrode
being of a size and flexibility to be advanced along with the
distal section of the body member through the right atrium and
coronary sinus into the coronary veins to a location adjacent the
wall of the left ventricle; (c) a terminal pin; (d) a conductive
member extending within said body member from said electrode for
providing an electrical path between said electrode and said
terminal pin; and (e) means for sealing said opening through the
outer wall of said body member.
5. For use with a cardiac rhythm management device, a low profile,
ventricular, transvenous, epicardial lead having: (a) an elongated,
flexible body member made of an electrically insulative material,
said body member having a proximal section, a distal section, an
outer wall extending the length of the body member, an opening
through said outer wall in said distal section and a lumen
extending from said opening through said outer wall, said proximal
section being stiffer than the distal section, said proximal
section possessing adequate axial stiffness and said distal section
being sized and sufficiently flexible to permit the distal section
to be advanced through the right atrium and coronary sinus into the
coronary vein; (b) an electrode capable of delivering
defibrillating pulses to the left ventricle of the heart and
coupled to the distal section of said body member, said electrode
being of a size and flexibility to be advanced along with the
distal section of the body member through the right atrium and
coronary sinus into the coronary veins to a location adjacent the
wall of the left ventricle; (c) a terminal pin; (d) a conductive
member comprising a conductive coil extending within said body
member from said electrode for providing an electrical path between
said electrode and said terminal pin, said conductive coil having a
biased area for retaining the electrode in the coronary vein; and
(e) means for sealing said opening through the outer wall of said
body member.
6. For use with a cardiac rhythm management device, a low profile,
ventricular, transvenous, epicardial lead having: (a) an elongated,
flexible body member made of an electrically insulative material,
said body member having a proximal section, a distal section, an
outer wall extending the length of the body member, an opening
through said outer wall in said distal section and a lumen
extending from said opening through said outer wall, said proximal
section being stiffer than the distal section, said proximal
section possessing adequate axial stiffness and said distal section
being sized and sufficiently flexible to permit the distal section
to be advanced through the right atrium and coronary sinus into the
coronary vein; (b) an electrode capable of delivering
defibrillating pulses to the left ventricle of the heart and
coupled to the distal section of said body member, said electrode
being of a size and flexibility to be advanced along with the
distal section of the body member through the right atrium and
coronary sinus into the coronary veins to a location adjacent the
wall of the left ventricle; (c) a terminal pin; (d) a conductive
member extending within said body member from said electrode for
providing an electrical path between said electrode and said
terminal pin; (e) deployable tines coupled to the body member for
retaining said electrode in the coronary vein, said tines being
detachable from said body member to permit explantation of the
lead; and (f) means for sealing said opening through the outer wall
of said body member.
7. The lead of claim 5 wherein said means for sealing said opening
includes a silicone flap.
8. The lead of claim 5 wherein said means for sealing said opening
includes a hydrophilic material that swells when in contact with
body fluids.
9. The lead of claim 5 wherein said means for sealing said opening
includes a plug deployable through said lumen.
Description
BACKGROUND OF THE INVENTION
[0001] I. Field of the Invention
[0002] The present invention relates to implantable devices used to
stimulate the heart to control the heart's rhythm. This invention
is more specifically directed toward leads used to connect a pulse
generator to the left side of the heart to provide defibrillating
pulses to the heart.
[0003] II. Description of the Prior Art
[0004] As set forth in U.S. Pat. No. 5,803,928 granted on Sep. 8,
1998 to Tockman et al, important health benefits can be derived by
positioning an electrode in a branch of the great vein of the heart
to treat tachycardia. Others have discussed positioning an
electrode in the vasculature of the left side of the heart to treat
heart failure. The present invention contemplates placing an
electrode there for purposes of defibrillation.
[0005] Not all leads are suitable for placement in the vasculature
of the left side of the heart. Many leads have too great a
diameter, are too inflexible, and include structures that do not
permit the lead to be safely and easily advanced through the
vasculature. Such problems are compounded when the lead must also
be suitable for delivery of defibrillation pulses.
SUMMARY OF THE INVENTION
[0006] As indicated above, it is often advantageous to
defibrillation therapy to the left ventricle of the heart. While it
is possible to secure a defibrillation electrode to the exterior of
the left ventricle, doing so involves cracking the chest wall and
other highly invasive and traumatic surgical protocols. Much of
this surgical trauma can be avoided through the use of a
transvenous lead. Placing the lead in the left ventricle can
increase the potential for clotting. Clear advantages can,
therefore, be derived by placing the electrode in a branch of the
coronary vein. However, for such a lead to be successfully
implanted in this fashion for effective delivery of therapy to the
ventricle, it must be of a design capable of meeting six critical
needs.
[0007] First, such a lead must be designed so that one or more of
its electrodes can be positioned in one of the coronary veins of
the left side of the heart. As such, the distal end of the lead
must follow a path which includes the right atrium, the coronary
sinus and one of the coronary veins.
[0008] Second, the lead must include a suitable shocking electrode.
To be suitable, the shocking electrode must be of a proper length,
be sufficiently supported for both placement and explant, and yet
flexible enough to travel through the venous structure.
[0009] Third, the lead must have an electrode capable of pacing and
sensing. This may be accomplished using the same electrode used for
shocking. Alternatively, separate electrodes on the lead can be
used to perform the pacing and sensing functions.
[0010] Fourth, proper fixation of the lead is key. Once the
electrode is properly positioned, it must remain in that position
indefinitely. Changes in position can be caused by a variety of
factors, including blood flow, if the lead is not properly fixed in
place.
[0011] Fifth, if an "over-the-wire" type design is used, the open
end of the lumen could be sealed once the guidewire is withdrawn.
Otherwise undesirable flow of blood through the lumen of the lead
might occur.
[0012] Finally, the terminal pins of the lead must be properly
sized. They must be sized for coupling to the defibrillator. They
also must permit removal of a guide catheter.
[0013] Leads constructed in accordance with the subject invention
meet each of these six critical criteria through the incorporation
of various specifically designed structures. First, leads of the
present invention have a proximal section possessing adequate axial
stiffness for torquing and pushing purposes. Such leads also have a
flexible distal section for traversing the required path. The outer
surface is coated with a lubricious material for ease of insertion.
The tip is designed to be atraumatic to heart and vascular tissue.
The lead is also designed to cooperate with a guidewire during the
implantation process.
[0014] Second, the defibrillation electrode is sufficiently
supported for placement and explant. The electrode is also properly
sized and sufficiently flexible to travel through the venous
structure. Once implanted, the electrode is capable of delivering
adequate defibrillation pulses to the heart.
[0015] Third, sensing or pacing is performed either using the same
electrode which delivers defibrillation pulses to the heart, or a
separate electrode. If a separate electrode is used, it must have
characteristics similar to the defibrillation electrode as
discussed above and the lead body structure should have
individually insulated conductive elements.
[0016] Fourth, any fixation device used to assure that the
electrode is maintained in the proper position is designed to not
interfere with efforts to place the electrode in the proper
position. Thus, rather than impacting the cross-section of the lead
during implantation, the fixation device either (a) biases in the
lead body's conductive coil; (b) comprises one or more dissolvable
polymers in the lead body to permit fibrotic attachment to the vein
wall; or (c) has deployable tines. The fixation mechanism may also
be made detachable to allow for explant of the lead.
[0017] Fifth, a guidewire will typically need to be used to
position the electrode properly. If the lead has a distal opening
and is passed over the guidewire, the distal opening is sealed once
the electrode is properly positioned. In accordance with the
present invention, this can be accomplished through the use of
either a silicone flap, a hydrophilic material which swells upon
fluid contact to close the distal opening, or the use of a
deployable plug.
[0018] Finally, the terminal pins of the lead are designed to
accommodate removal of a guide catheter. Either the terminal pins
must be made small enough or the terminal pins must be
removable.
[0019] More specifically, the present invention provides a lead
suitable for both delivery of defibrillation pulses and placement
in the vasculature of the heart. In one embodiment, a single lumen
lead is provided. This lead includes an electrically conductive
single open-lumen inner conductor coil comprising a winding of
multiple wires to reduce electrical resistance. The coil is covered
with an insulative material such as silicone,
polytetrafluoroethylene (PTFE) or polyurethane. The proximal end is
equipped with a terminal connector that can be plugged into the
pulse generator. Just distal of the terminal connector is a
self-sealing disk that permits passage of a guidewire and seals
upon removal of the guidewire. Near the distal end of the lead are
one or more electrodes specifically designed for flexibility and
delivery of defibrillation pulses. The distal end, itself, includes
a tip designed to be atraumatic and to dilate the venous structures
to facilitate lead implantation. The lead may also include a
fixation device for retaining the lead in the proper position.
[0020] Other embodiments of the invention provide a multi-lumen
lead having one or more conductive cables passing through the
lumens and attached to one or more electrodes. Again, a terminal
connector for each cable, a self-sealing disk and an atraumatic tip
are provided.
[0021] Further information related to the present invention and the
advantages it offers can be derived from a review of the following
detailed description of the invention in conjunction with the
drawings which are a part of this specification. The specification
is not intended to be limiting. Instead, the scope of the invention
is defined by the claims when interpreted broadly to include a full
range of equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a perspective view showing the distal end section
of the lead of the present invention.
[0023] FIG. 2 cross-sectional view of the distal section of the
lead shown in FIG. 1.
[0024] FIG. 3 is a cross-sectional view of the proximal section of
the lead shown in FIG. 1.
[0025] FIG. 4 is a perspective view of the distal section of a
second embodiment of the present invention.
[0026] FIG. 5 is a cross-sectional view of the distal section of
the embodiment shown in FIG. 4.
[0027] FIG. 6 is a cross-sectional view of the proximal section of
the embodiment shown in FIG. 4.
[0028] FIG. 7 is a side view showing a first electrode design.
[0029] FIG. 8 is a side view showing a second electrode design.
[0030] FIG. 9 is a side view showing a third electrode design.
[0031] FIG. 10 is a side view of a self-sealing disk used to seal a
lumen of the lead.
[0032] FIG. 11 is an end view of the self-sealing disk shown in
FIG. 10.
[0033] FIGS. 12-16 are each cross-sectional views showing
alternative multi-lumen lead designs.
[0034] FIG. 17 shows a first embodiment of a dual in-line
connector.
[0035] FIG. 18 shows a second embodiment of a dual in-line
connector.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] A first embodiment of the invention is shown generally in
FIGS. 1-3. The lead 10 includes a distal section 12 shown in FIGS.
1 and 2 and a proximal section 14 shown in FIG. 3. The distal
section 12 includes a coil-shaped electrode 16. The electrode 16
can be made of a single wire. However, multi-filar wire coil is
preferred. The coil-shaped electrode 16 surrounds a silicone tubing
18. The coil-shaped electrode 16 is also electrically coupled to a
conductive coil 20 which is used to carry pulses between the
electrode 16 and a terminal pin 22. The coil-shaped electrode 16 is
preferably a winding of multiple wires coupled together. This also
serves to significantly reduce electrical resistance. Suitable wire
materials include platinum clad titanium, platinum clad tantalum,
or platinum coated MP35N wire. The conductive coil 20 preferably
has a biased area that can be used to help retain the lead in the
desired position in the vein. The terminal pin 22 is used to couple
the lead 10 to a cardiac rhythm management device such as an
implantable defibrillator. The terminal pin 22 is preferably
removable and/or small enough to permit the walls of a lumen of a
guide catheter to pass over pin 22.
[0037] FIGS. 1-3 show other important features of the invention.
For example, an insulative layer 24 surrounds the conductive coil
20. Suitable materials for the insulative layer 24 include
silicone, polytetrafluoroethylene (PTFE) and polyurethane. Silicone
offers the advantages of being very flexible and soft. PTFE offers
the advantages of being thin, durable, and reduces abrasion.
Polyurethane is stiffer than silicone, but smoother and more
durable. The insulative layer 24 may include a combination of these
materials. For example, the majority of the insulative layer might
be silicone. A layer of PTFE might be placed between the coil 20
and the silicone on approximately two-thirds the length of the lead
10 to stiffen the proximal section to facilitate advancing the lead
10 over a guidewire during insertion of the lead. Polyurethane
might be used as an outer layer over the silicone to prevent
abrasion of the vessel wall as the lead is implanted a coating of a
lubricious material may also be provided. Ideally, the proximal end
section will be stiffer than the distal section so that the
proximal section has sufficient axial stiffness to allow the lead
to be advanced and the distal section is sufficiently flexible to
be routed along the desired path and at the same time be
sufficiently atraumatic.
[0038] FIGS. 1 and 2 show that the distal section 12 terminates
with an atraumatic tip 26 at the distal end. The tip 26 is designed
to completely cover the electrically conductive coil 20 to prevent
vessel erosion. The tip 26 also acts to dilate the venous structure
to facilitate implantation of the lead 10. Suitable materials for
the tip 26 include silicone or other soft, pliable polymers.
[0039] FIGS. 1 and 2 also show a fixation device 28 incorporating a
plurality of tines 30. These tines 30 are preferably deployable and
act to increase the mechanical pressure against the vessel wall to
hold the lead 10 in place. Suitable materials include silicone and
polyurethane. The lead could be microtextured to permit fibrotic
attachment to the wall of the coronary vein. The tines could also
be made detachable or absorbable in the event the lead needs to be
explanted. Materials could include poliglecaprone 25, polyglactin
910 or polydioxanone.
[0040] FIGS. 4-6 show an alternative embodiment of the present
invention. This embodiment incorporates a plurality of small ring
electrodes 40 in place of the wire coil electrode 16. A soft,
flexible, insulative material covers the conductive coil 20 between
the ring electrodes. The conductive coil 20, of course, carries
current from the terminal pin 22 to each ring electrode. A
plurality of cables could be used in place of the coil 20 if it is
desired to have the ring electrodes 40 perform separate functions,
i.e., pacing, defibrillating or sensing.
[0041] FIGS. 7-9 show various alternative electrode designs. In
FIG. 7, the electrode 40 comprises silicone rubber doped with
conductive particles. In FIG. 8, the electrode 40 merely comprises
an exposed section of the conductive coil 20. In FIG. 9 the
electrode 40 is a conductive braided wire screen electrically
coupled to the conductive coil 20. Of course, a standard ring
electrode might also be used, but it would be less flexible than
the electrode arrangements shown in FIGS. 7-9.
[0042] A significant feature of the present invention is a
deployable plug comprising the sealing disk 50 shown in FIGS. 10
and 11. This disk 50 is deployable so that it resides in the lumen
17 of the lead 10 to block the unintended passage of fluids through
the lumen. The disk 50 is made of a low durometer silicone and has
an orifice 52 that extends through it. The orifice 52 is sized to
allow a guidewire to pass through it. However, when the guidewire
is removed, the orifice seals behind it. Alternatively, the disk 50
could have a self-sealing flap or made of a hydrophilic material
designed to expand when subjected to moisture to seal the
lumen.
[0043] The present invention is not limited to a single lumen lead
design. FIGS. 12-16 show separate multilumen designs fully within
the scope of the invention. FIG. 12 shows a pair of concentric
lumens 60 and 62. Lumen 60 is designed to accommodate a guidewire.
A conductive cable resides in lumen 62. FIG. 13 shows a pair of
concentric lumens 60 and 62 and a third lumen 64 that functions as
a guide tube.
[0044] FIGS. 14 and 15 show a design that includes a first lumen 70
through which a cable conductor 71 passes and a lumen 72 to
accommodate a guidewire, injection of fluoroscopic dye or the like.
Finally, FIG. 16 shows an arrangement incorporating a larger
central lumen 80 and smaller top and bottom lumens 82 and 84. The
top lumen 82 can each include a braided cable 71 which replaces the
conductive coil. The larger central lumen 80 can accommodate a
guidewire. This lumen may be coated with a lubricious material so
that the lead slides easily with respect to a guide wire used
during implantation of the lead. The outer wall of the lead body
can also be coated with a lubricious material to reduce friction
between the lead and vessel wall. The bottom lumen can be used for
dye injection or for another braided cable if the lead includes
multiple electrodes used for differing purposes. When two such
cables are provided, two terminal pins 22 or a dual in-line
connector will be required. The first cable can be coupled to an
electrode for delivery of defibrillating pulses. The second cable
can be coupled to a second electrode for delivering pacing pulses
to the heart or to sense the electrical activity of the heart.
Alternatively, a dual in-line connector 90 of the types shown in
either FIGS. 17 and 18 could be used. Each dual in-line connector
has a first conductive element 92 and a second conductive element
94. In FIG. 17, the first and second conductive elements are spaced
apart bands electrically insulated from each other. Each band is
electrically coupled to a separate electrode by a wire or the like.
In FIG. 18, the electrically conductive elements are a pair of
coaxial wire coils, one having a smaller diameter than the other.
Of course, other multiple arrangements can be used without
deviating from the invention.
* * * * *