U.S. patent application number 16/796895 was filed with the patent office on 2020-08-27 for apparatus, systems, and methods to improve atrial fibrillation outcomes involving the left atrial appendage.
The applicant listed for this patent is Ablation Innovations, LLC. Invention is credited to Clayton A. Kaiser, Daniel Walter Kaiser, Katie Miyashiro, Robert A. Pickett.
Application Number | 20200269059 16/796895 |
Document ID | / |
Family ID | 1000004837476 |
Filed Date | 2020-08-27 |
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United States Patent
Application |
20200269059 |
Kind Code |
A1 |
Kaiser; Daniel Walter ; et
al. |
August 27, 2020 |
APPARATUS, SYSTEMS, AND METHODS TO IMPROVE ATRIAL FIBRILLATION
OUTCOMES INVOLVING THE LEFT ATRIAL APPENDAGE
Abstract
Apparatus, systems, and methods are provided for monitoring AF
episodes, delivering ATP pulses, and/or achieving electrical
isolation of the left atrial appendage (LAA) of a patient's heart
and/or preventing thrombus formation after electrical isolation.
For example, devices are provided that may implanted from within
the left atrium, e.g., to isolate the LAA, prevent thrombus
formation within the LAA, facilitate endothelialization, and/or
deliver pacing.
Inventors: |
Kaiser; Daniel Walter;
(Nashville, TN) ; Pickett; Robert A.; (Nashville,
TN) ; Miyashiro; Katie; (Portland, OR) ;
Kaiser; Clayton A.; (Nashville, TN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ablation Innovations, LLC |
Brentwood |
TN |
US |
|
|
Family ID: |
1000004837476 |
Appl. No.: |
16/796895 |
Filed: |
February 20, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62808130 |
Feb 20, 2019 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61N 1/37512 20170801;
A61B 2018/00577 20130101; A61N 1/3756 20130101; A61B 17/12031
20130101; A61N 1/37211 20130101; A61B 17/12122 20130101 |
International
Class: |
A61N 1/375 20060101
A61N001/375; A61N 1/372 20060101 A61N001/372; A61B 17/12 20060101
A61B017/12 |
Claims
1. A leadless pacemaker device for implantation within or near a
left atrial appendage extending from a left atrium of a heart to
monitor and/or treat a patient with conduction abnormalities and/or
cardiac dysrhythmias, the device comprising: a battery capable of
storing electrical energy; at least one electrode capable of
sensing and pacing the left atrium; a control processor capable of
processing data; a communication module to communicate outside of
the patient; and a cover portion designed to prevent thrombus from
within the left atrial appendage of the left atrium to embolize out
of the left atrial appendage of the left atrium; wherein at least a
portion of the device comprises a linear chain of subunits coupled
together by connectors, wherein the connectors configured to allow
each subunit to change orientation relative to any adjacent
subunits.
2. The device of claim 1, wherein the subunits are cylindrical in
shape, wherein subunits define a length that is between about ten
and thirty millimeters (10-30 mm), and a diameter that is between
about three and six millimeters (3-6 mm).
3. The device of claim 1, further comprising that the at least one
electrode capable of sensing and pacing the left atrium is
configured to be located against the wall of the left atrium
outside of the left atrial appendage and at least two millimeters
(2 mm) away from the ostium of the left atrial appendage.
4. The device of claim 1, further comprising at least one electrode
configured for delivering ablation energy.
5. The device of claim 1, wherein the subunits are configured to
undergo a first conformational change upon entering the left atrium
and then undergo a second conformational change after being
positioned within the left atrial appendage.
6-13. (canceled)
14. A leadless pacemaker system, comprising: a delivery sheath
comprising a proximal end, a distal end sized for introduction into
a left atrium of a heart, and a lumen extending between the
proximal and distal ends; a pacemaker device comprising a plurality
of elements deployable sequentially through the lumen from the
distal end into the left atrium, the elements configured to adopt
an expanded configuration within the left atrium; an actuator for
advancing the elements from the left atrium into the left atrial
appendage, and releasing the elements to implant the device within
the left atrial appendage.
15. The system of claim 14, wherein the elements are connected
sequentially together by connectors between adjacent elements, the
connectors biased to a nonlinear shape such that, when the elements
are deployed from the distal end of the delivery sheath, the
connectors automatically cause the elements to spiral or fold into
the expanded configuration.
16. The system of claim 15, further comprising a constraining
mechanism for constraining the elements in a contracted
configuration having a lower profile than the expanded
configuration before advancing the elements into the left atrial
appendage.
17. The system of claim 16, wherein the actuator is configured to
release the elements from the contracted configuration once
advanced into the left atrial appendage such that the connectors
bias the elements back towards the expanded configuration to secure
the elements within the left atrial appendage.
18. The system of claim 14, wherein the actuator comprises a
plunger slidable within the lumen of the delivery sheath.
19. The system of claim 14, wherein the elements are connected
sequentially together by connectors between adjacent elements, and
wherein the actuator is coupled to the connectors to direct the
connectors to a nonlinear shape and cause the elements to spiral or
fold into the expanded configuration.
20. The system of claim 19, further comprising a constraining
mechanism for constraining the elements in a contracted
configuration having a lower profile than the expanded
configuration before advancing the elements into the left atrial
appendage.
21. The system of claim 29, wherein the actuator is further
configured to direct the elements from the contracted configuration
towards the expanded configuration to secure the elements within
the left atrial appendage.
22. The system of claim 14, further comprising a cover operatively
coupled to the elements and slidably received within the lumen such
that the cover is deployed from the lumen after deploying the
elements, the cover expandable for isolating the left atrial
appendage from the left atrium after advancing the elements into
the left atrial appendage.
23. The system of claim 22, further comprising one or more
electrodes carried by the cover, the one or more electrodes
configured to contact a wall of the left atrium outside the left
atrial appendage when the left atrial appendage is isolated by the
cover.
24. The system of claim 23, further comprising a processor coupled
to the one or more electrodes configured to: identify a cardiac
condition of the heart warranting pacing; and deliver electrical
pacing via at least one of the one or more electrodes until the
cardiac condition is remedied.
25. The system of claim 14, wherein the pacemaker device further
comprises a plurality of electrodes coupled to a power source, the
electrodes configured to deliver energy to ablate atrial tissue to
electrically isolate the left atrial appendage from the rest of the
left atrium.
26. The system of claim 14, wherein the electrodes carry one or
more electrodes, the system further comprising a power source
coupled to the one or more electrodes to deliver energy to heat
tissue adjacent tissue to secure the elements within the left
atrial appendage.
27. A method for implanting a leadless pacemaker device within a
left atrial appendage extending from a left atrium of a heart,
comprising: introducing a distal end of a delivery sheath into the
left atrium; deploying a plurality of elements of the pacemaker
device sequentially from the distal end into the left atrium, the
elements adopting an expanded configuration within the left atrium;
advancing the elements from the left atrium into the left atrial
appendage; and releasing the elements to implant the device within
the left atrial appendage.
28-41. (canceled)
Description
RELATED APPLICATION DATA
[0001] The present application claims benefit of co-pending
provisional application Ser. No. 62/808,130, filed Feb. 20, 2019,
the entire disclosure of which is expressly incorporated by
reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates to apparatus, systems, and
methods for improving atrial fibrillation outcomes involving the
left atrial appendage. More specifically, implantable devices are
provided that are designed for placement within a patient's body,
e.g., within the left atrial appendage of the atrium of a patient's
heart to monitor and treat abnormal rhythms.
BACKGROUND
[0003] Atrial fibrillation ("AF") is the most common sustained
cardiac arrhythmias. Cardiac ablation of atrial fibrillation is one
of most common cardiac procedures. The cornerstone of AF ablation
procedures have been pulmonary vein isolation ("PVI"). However, in
recent years, non-pulmonary vein triggers have been identified. One
of the most common non-pulmonary vein triggers is the left atrial
appendage ("LAA"). Therefore, there is a growing interest in
performing LAA isolation during ablation procedures. However, there
are technical difficulties in creating electrical isolation of the
LAA. In addition, numerous reports suggest that there is increased
risk of thromboembolic events following LAA isolation. Inadequate
function of the LAA after electrical isolation is felt to be
responsible. After electrical isolation, the LAA does not squeeze
adequately. As a result, blood can coagulate to form a thrombus in
the LAA. This thrombus can then embolize to other parts of the
body.
[0004] The LAA has various morphologies and sizes. An ablation tool
needs to be adaptive enough to accommodate these differences. Some
LAA have a straight structure (`windsock` morphology) while other
LAA morphologies include a sharp bend (`chicken-wing` morphology).
In addition, an ablation tool that prevents thrombus formation
within the LAA is optimal. There are data that suggest that some
patients who are in sinus rhythm remain at risk for thrombus
formation in the LAA after electrical isolation of the LAA.
[0005] The only commercially available leadless pacemaker is
intended to be placed in the right ventricle. There are apparently
next generation leadless pacemakers under development to enable
placement within the right atrium. However, there are no known
devices available or in development that describes a leadless
pacemaker designed to be placed within the left atrium.
[0006] Therefore, improved tools to improve AF ablation procedures,
e.g., by monitoring AF episodes, delivering ATP pulses, and/or
isolating the LAA without the increased risk of thromboembolic
events, may be useful.
SUMMARY
[0007] The present invention relates to apparatus, systems, and
methods for monitoring AF episodes, delivering ATP pulses, and/or
achieving electrical isolation of the left atrial appendage (LAA)
of a patient's heart and/or preventing thrombus formation after
electrical isolation.
[0008] More particularly, the systems and methods herein may
include a device that is implanted from within the left atrium,
isolates the LAA, and prevents thrombus formation within the LAA.
In addition, the device may include material that facilitates
endothelialization. In an exemplary embodiment, the device may be
placed within the body through a sheath and takes a desired shape
after leaving the deployment sheath.
[0009] Anti-tachycardia pacing (ATP) delivered from traditional
pacemakers has been shown to reduce atrial fibrillation burden. It
is likely that a leadless pacemaker implanted within the left
atrial appendage can also deliver ATP pulses to terminate atrial
arrhythmias. A pacemaker in the left atrial appendage can reduce AF
burden and prevent thrombus from forming in the left atrial
appendage.
[0010] In general, patients who go into AF need to be on blood
thinners to prevent thrombus formation. A medical device placed
into the LAA may help prevent thrombus from forming inside the LAA.
In addition, the LAA also provides potential space for a processor
and battery. In addition, this space may be used for monitoring
purposes. This enables the device to monitor for AF recurrence and
alert patients and/or their caretakers. In addition, if the
implanted device is able to deliver anti-tachycardia pacing (ATP)
pulses to the atrial tissue, the device may help pace-terminate AF
episodes if the ablation/isolation procedure is unsuccessful. In
addition, patients with AF often demonstrate both fast heart rates
(tachycardia) as well as slow heart rates (bradycardia). The device
may pace the heart in response to slow heart rates to treat these
abnormal rhythms.
[0011] Most AF triggers or initiators originate from the left
atrium. Specifically, the large majority of atrial tachycardia
episodes that initiate and sustain AF episodes come from the
pulmonary veins (which connect to the left atrial) and the left
atrial appendage. These atrial tachycardia episodes can be
interrupted and terminated via anti-tachycardia pacing (ATP).
However, ATP episodes are more effective if the ATP pulses are in
proximity to the originator of the atrial tachycardia. Therefore,
delivering ATP pulses from the left atrium is likely to be more
effective than ATP delivery from the right atrium.
[0012] Anti-tachycardia pacing (ATP) may be delivered from an
implantable pacemaker implanted within the left atrial appendage to
terminate atrial tachycardia and atrial flutter. By terminating
regular rhythms, a pacemaker in the left atrial appendage may
reduce AF burden and prevent thrombus from forming in the left
atrial appendage.
[0013] In accordance with one embodiment, the LAA isolating device
is aligned with electrodes. These electrodes may enable the device
to be visualized on mapping systems. This enables mapping systems
that use impedance-based mapping or magnetically-based mapping to
be visualized to help deploy the device optimally into the LAA. In
some embodiments, the device may also include materials to enhance
visualization using other methods, such as echocardiography and
fluoroscopy, to further aid optimal deployment and placement into
the LAA.
[0014] In addition, the system may include a monitor of the
patient's rhythm. In one embodiment, after the device is deployed
and the LAA is isolated, the system is still able to sense and pace
the heart. In one embodiment, the device may pace the heart in
order to terminate abnormal rhythms. In another embodiment, the
device may identify atrial fibrillation and send messages outside
of the body. In order to record and send transmissions, in some
embodiments, the device may include a battery and/or other
implanted power source. In some embodiments, the battery may be
charged from the outside world, e.g., inductively, using
ultrasound, electromagnetic energy, or otherwise using an external
device that communicates with the implanted device.
[0015] In accordance with another embodiment, the system may
include an elongate member that is designed to be deployed through
a specialized deployment sheath into the left atrial appendage. The
device coils on itself to fill, attach, and then close off the left
atrial appendage from the rest of the left atrium. In addition,
electrodes may align the elongate member. These electrodes permit
deployment using standard mapping systems (e.g., using impedance or
magnetic based systems) as well as ablation to electrically isolate
the left atrial appendage. In other embodiments, the device may use
electroporation and laser ablation to ablate tissue. In other
embodiments, the device may be cooled to freeze LAA tissue to
isolate the appendage. In addition, the device may provide a radial
force to compress the tissue to induce electrical isolation.
[0016] The elongate member may be designed to coil on itself. In
addition or alternatively, an inner cable or the like, the
materials of the coil itself, or positioning from the delivery
system may be utilized to enlarge the coil to optimize contact and
force. In other embodiments, electrodes are used to help guide the
closure device into place and are then withdrawn. In another
embodiment, many or all of the electrodes are deployed and left
within the left atrium and/or left atrial appendage.
[0017] In some embodiments, detailed imaging is performed on the
left atrium and left atrial appendage to better determine the
anatomy to facilitate electrical isolation and device deployment.
Imaging may be obtained using normal mapping electrodes used during
the ablation procedure, or using catheters and electrodes
specifically designed to map the LA and LAA. In another embodiment,
ultrasound imaging, such as obtained from a transesophageal
echocardiogram ("TEE") images or intracardiac echocardiogram images
are combined with other mapping techniques to best understand the
LAA anatomy. For example, an intracardiac echocardiography ("ICE")
catheter may be advanced into the LAA to determine the anatomy. The
walls and anatomy of the LAA may be visualized and identified on
ultrasound imaging and then incorporated into a three-dimensional
map to determine optimal ablation device size/length as well as
device deployment within the LAA. A specialized tip may be placed
on the tip of the ICE catheter to prevent traumatic damage to the
LAA.
[0018] In another embodiment, the isolation device combines aspects
of an LAA closure device. In one embodiment, electrodes are used to
guide device deployment which combines self-expanding nitinol with
electrodes for positioning and electrical isolation. In another
embodiment, a sponge-like material is used to occlude the LAA. By
leading the sponge-like material with electrodes, the sponge-like
material may be optimally deployed within the LAA. The sponge-like
material may then help lock the electrodes in place and decrease
the risk of device embolization.
[0019] In another embodiment, after detailed mapping is created,
the sponge-like material is cut to optimally fit within the LAA.
For example, a desired mass or section of sponge-like material may
be formed using a 3D printing system. In one embodiment, the LAA
closure material is printed using a specially-designed 3D printer.
In another embodiment, the sponge-like material is trimmed to fit
the LAA anatomy. In this embodiment, the 3D printer only carves the
outside of the sponge-like material--it does not lay down the
material. The sponge-like material can then be collapsed to fit
within a delivery sheath and deployed within the LAA. The
sponge-like material may be aligned with electrodes. In another
embodiment, there are electrodes leading the sponge-like material,
behind the sponge-like material, located between the beginning and
end of the sponge-like material, or a combination thereof.
[0020] In another embodiment, two sheaths are used to electrically
isolate and then close the LAA. In this embodiment, one sheath is
used to map the LAA and facilitate safe deployment of the second
sheath into the LAA.
[0021] In exemplary embodiments, electrical isolation may occur
through pinching or clamping tissue of the LAA. The closure device
may be coated with insulation material to force electrical current
to optimize tissue ablation.
[0022] The connection between the electrodes on the closure device
and the external world need to be cut or released at some point.
This connection may be rotated to release (a screw mechanism),
pulled into the delivery sheath to release, or may be designed to
break away with force. In another embodiment, electrical current is
used to burn or electrolytically separate the connection to
facilitate release.
[0023] In another embodiment, the closure device is used to deliver
a chemical that prevents the body from healing the ablation. In one
embodiment, the device is covered with chemotherapy agents that
prevent electrical reconnection. Therefore, the electrodes may
deliver RF or electrical current to induce electroporation ablation
to the LAA. The device may combine electroporation, chemical
ablation, and pressure to maintain electrical isolation. The device
may also contain distal electrodes capable of sensing distal LAA
electrical signals in order to verify electrical isolation. The
closure device may include a battery to maintain electrical
ablation. In addition, the closure device may include a
communication system to communicate outside of the body. In one
embodiment, the closure device can be charged from outside the body
using ultrasound energy. The device may then use this energy to
measure left atrial pressure or pace the heart.
[0024] In response sinus slow heart rates such as bradycardia or
sinus arrest, the devices herein may be configured to pace the
atrium to speed up the heart rate. However, pacing the LAA after
electrical isolation may not increase the heart rate since the LAA
will be electrically isolated from the rest of the heart.
Therefore, the device needs to be implanted within the LAA to
prevent thrombus formation; however, the electrodes need to have
contact to atrial tissue outside of the LAA in order to affect the
heart rate. Therefore, in an alternatively embodiment, the device
may be configured to be positioned within the LAA but has
electrodes adjacent atrial tissue outside the LAA in order to pace
heart tissue to speed up the heart rate.
[0025] Furthermore, AF is often initiated by fast and sometimes
irregular heart rhythms such as atrial flutter or atrial
tachycardia. By deliver pacing pulses at a rate faster than the
sensed atrial rate, overdrive pacing is often able to terminate the
abnormal atrial rhythm. Therefore, delivering ATP from the device
can help terminate tachyarrhythmias. In addition, even though the
device is positioned in the left atrial appendage, this location is
often overhanging the left ventricle. Therefore, by delivering high
output pacing, the device may be designed to treat abnormally slow
ventricular rates in the setting of poor atrio-ventricular
conduction, such as heart block.
[0026] In addition, the closure device may be covered in drug
eluting material that prevents the body from healing the lesion. In
one embodiment, the closure device delivers an agent that prevents
electrical reconnection; this agent may include one or more of
sirolimus, paclitaxel, zotarolimus, everolimus, biolinx polymer, a
steroid, and ridaforolimus material. In addition or alternatively,
the device may include a steroid eluting agent. In another
embodiment, the closure device is designed to facilitate
endothelialization, including containing endothelial progenitor
cell capture material, basic polymeric woven or non-woven
materials, or surfaces roughened through mechanical or chemical
methods. In another embodiment, the closure device is covered with
radioactive material that facilitates electrical isolation.
[0027] Other aspects and features including the need for and use of
the present invention will become apparent from consideration of
the following description taken in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a side view of an exemplary embodiment of a
leadless pacemaker device designed for implantation within the left
atrial appendage that includes three portions deployed from a
distal portion of a delivery sheath.
[0029] FIG. 2 is a cross-sectional view of a region of a heart
showing the device of FIG. 1 being introduced into a left atrial
appendage of the heart.
[0030] FIG. 3 is a schematic illustration of the device of FIGS. 1
and 2 being deployed.
[0031] FIG. 4 is a schematic illustration of a view of the device
of FIGS. 1-3 fully deployed within the left atrial appendage as
seen from the left atrium.
[0032] FIG. 5 is a cross-sectional view of a region of a heart
showing another embodiment of a leadless pacemaker advancing into
the left atrial appendage after conformational change within the
left atrium.
[0033] FIG. 6 is a schematic illustration of an exemplary
embodiment of a device for electrical isolation of a left atrial
appendage before deployment.
[0034] FIG. 7 is a cross-sectional view of a region of a heart
showing another embodiment of a device for electrical isolation of
a left atrial appendage of the heart after deployment.
[0035] FIG. 8 is a cross-sectional view of a region of a heart
showing yet another embodiment of a device being deployed within a
left atrial appendage of the heart.
[0036] FIG. 9 is a schematic illustration of an exemplary
embodiment of an electrical connection for a device for electrical
isolation of a left atrial appendage, such as that shown in FIG.
8.
[0037] FIG. 10 is a schematic illustration of another embodiment of
a leadless pacemaker device designed for implantation within or
near a left atrial appendage.
[0038] FIG. 11 is a simplified functional block diagram of an
exemplary embodiment of a leadless pacemaker device.
[0039] FIG. 12 is a schematic illustration of still another
embodiment of a leadless pacemaker designed for implantation within
the left atrial appendage.
[0040] FIGS. 13A-16B show an exemplary method for delivering the
device of FIG. 10.
[0041] FIGS. 17A-19B show an exemplary method for delivering
another leadless pacemaker into the left atrial appendage.
[0042] FIG. 20 is a schematic illustration of yet another
embodiment of a leadless pacemaker designed for deployment into or
near a left atrial appendage.
[0043] FIG. 21A-26 shows an exemplary method for deploying the
device of FIG. 20.
[0044] FIGS. 27A-27B show other exemplary embodiments of a leadless
pacemaker designed for deployment within the left atrial
appendage.
[0045] FIG. 28 is a flow diagram of an exemplary method for
deploying a leadless pacemaker device.
[0046] FIG. 29 is a flow diagram of another exemplary method for
deploying a leadless pacemaker device.
[0047] FIGS. 30A-30C are cross-sectional views of a region of a
heart showing another embodiment of a leadless pacemaker device
being deployed within the left atrial appendage of a heart.
[0048] FIGS. 31A-31D show an exemplary method for manipulating a
leadless pacemaker device for introduction into a left atrial
appendage of a heart.
[0049] FIGS. 32A and 32B are side views of another exemplary
embodiment of a leadless pacemaker device.
[0050] FIG. 33 is a side view of still another example of a
leadless pacemaker device.
[0051] FIGS. 34A-34C are cross-sectional views of a region of a
heart showing a method for deploying the device of FIG. 33 within
the left atrial appendage of a heart.
[0052] FIGS. 35A and 35B are side views of yet another example a
leadless pacemaker device in expanded and contracted conditions,
respectively.
[0053] FIGS. 36A-36D are side views of yet another example a
leadless pacemaker device being manipulated between expanded and
contracted conditions.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0054] Before the exemplary embodiments are described, it is to be
understood that the invention is not limited to particular
embodiments described, as such may, of course, vary. It is also to
be understood that the terminology used herein is for the purpose
of describing particular embodiments only, and is not intended to
be limiting, since the scope of the present invention will be
limited only by the appended claims.
[0055] Where a range of values is provided, it is understood that
each intervening value, to the tenth of the unit of the lower limit
unless the context clearly dictates otherwise, between the upper
and lower limits of that range is also specifically disclosed. Each
smaller range between any stated value or intervening value in a
stated range and any other stated or intervening value in that
stated range is encompassed within the invention. The upper and
lower limits of these smaller ranges may independently be included
or excluded in the range, and each range where either, neither or
both limits are included in the smaller ranges is also encompassed
within the invention, subject to any specifically excluded limit in
the stated range. Where the stated range includes one or both of
the limits, ranges excluding either or both of those included
limits are also included in the invention.
[0056] Unless defined otherwise, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention belongs. Although
any methods and materials similar or equivalent to those described
herein can be used in the practice or testing of the present
invention, some potential and exemplary methods and materials are
now described.
[0057] It must be noted that as used herein and in the appended
claims, the singular forms "a," "an," and "the" include plural
referents unless the context clearly dictates otherwise. Thus, for
example, reference to "a compound" includes a plurality of such
compounds and reference to "the polymer" includes reference to one
or more polymers and equivalents thereof known to those skilled in
the art, and so forth.
[0058] Turning to the drawings, FIG. 1 shows an exemplary
embodiment of an ablation device 8 for electrical isolation of a
left atrial appendage ("LAA"). In this example, the ablation device
8 includes three components, segments, or portions that are
introduced, deployed, and remain within the vicinity of the LAA: an
occluding portion 21, an ablation/compression portion 31, and an
anchoring portion 41. The components of the device 8 may be
introduced and/or deployed using a deployment sheath or other
tubular and/or elongate member 11. The components may be separate
devices that may be deployed sequentially or they may be components
of a single integral device including different regions. In the
embodiment shown, the deployment sheath 11 includes one or more
electrodes 12 (two shown) on its distal end to facilitate
positioning the components of the device 8. In some embodiments,
the distal end of the sheath 11 may be biased to a predetermined
shape, e.g., including a bend or curve to facilitate the components
of the device 8 being deployed from the deployment sheath 11 in a
controlled method.
[0059] The occluding portion 21 may also be lined by or otherwise
include a plurality of electrodes 22. The occluding portion 21 may
be a self-expanding disc to close off the LAA from the rest of the
left atrium ("LA") of a subject's heart. In another embodiment, the
occluding portion 21 is biased to a predetermined helical and/or
conical shape, e.g., that spirals on itself like a pyramid, that
may be shaped to completely close off the LAA when deployed.
Optionally, the occluding portion 21 may be made of or covered in
certain material that facilitates endothelialization and/or
minimizes platelet aggregation.
[0060] The ablation/compression portion 31 is designed to be
enlarged at the ostium of the LAA to electrically isolate the LAA.
The ablation/compression portion 31 may be lined by and/or
otherwise include electrodes 32 that may be monitored and/or
identified, e.g., using an external imaging and/or mapping system
(not shown). In addition, the ablation/compression portion 31
includes one or more electrodes 32, e.g., a plurality of
spaced-apart electrodes as shown, which may be used to deliver
radiofrequency energy, electroporation, freezing temperature, or
force to the tissue at the LAA ostium to electrically isolate the
LAA from the rest of the LA. The ablation/compression portion 31
may also include one or more tines or other fixturing elements 33
to prevent device movement and/or embolization of the device 8
after deployment. The ablation/compression portion 31 may have an
inner cable or plunger (not shown) that enables the portion 31 to
be enlarged after deployment to optimize radially force and tissue
contact.
[0061] With continued reference to FIG. 1, the anchoring portion 41
may also include one or more anchoring portion electrodes 42, e.g.,
a plurality of spaced-apart electrodes as shown, to help position
the anchoring portion 41 within the LAA. The anchoring portion 41
may also include a plurality of anchoring portion tines or other
fixturing elements 43 spaced apart along the anchoring portion 41
to help anchor the device 8 within the LAA to prevent movement
and/or embolization of the device 8.
[0062] In addition, the device 8 may also include an electrical
connector 25, e.g., for detachably coupling one or more components
of the device 8 to an elongate deliver member (not shown). For
example, as shown in FIG. 1, an electrical connector 25 may be
included on a proximal end of the occluding portion 21, although,
in addition or alternatively, an electrical connector may also be
included on the ablation/compression portion 31, or even the
anchoring portion 41 (not shown). The electrical connector 25
includes one or more electrical connections, e.g., coupled to one
or more wires or electrical leads (not shown) between the
electrodes 22, 32, 42 on the device components and a controller
and/or other devices external to the patient (not shown) to
facilitate device positioning and ablation of cardiac tissue.
[0063] Optionally, the electrical connector 25 may have a
specialized cover (not shown) that once the connection is
decoupled, the electrical components are covered to prevent
exposure within the heart. For example, the electrical connector 25
may be part of the ablation/compression segment 31, such that after
the electrical connections are decoupled, the electrical
connections will not have access to blood within the LA by the
occluding portion 21.
[0064] In another embodiment, the occluding portion electrodes 22
may be used to measure impedance across the occluding section 21,
e.g., to monitor for complete coverage of the LAA ostium. In one
embodiment, the impedance between the occluding portion electrodes
22 may be used as a surrogate for comprehensive contact between
loops of the pyramid shape to identify if there are any gaps in the
occluding portion 21.
[0065] FIG. 2 is a cross-sectional view of a portion of a patient's
heart, showing the device 8 of FIG. 1 located within a left atrial
appendage 92 adjacent a left atrium 90 of the heart. As shown, a
distal end of the deployment sheath 11 carrying deployment sheath
electrodes 12 may be introduced into the patient's body, e.g.,
percutaneously into the patient's vasculature, and advanced into
the LA 90 and into the LAA 92, e.g., by manipulating a proximal end
of the sheath 11 (not shown), to introduce and deploy the
components 21, 31, 41 of the device 8. For example, as shown, when
the device 8 is fully deployed, the occluding portion 21 has been
coiled like a rounded pyramid or cylindrical coil to cover the left
atrial appendage ostium 91. The ablation/compression portion 31 is
located at the ostium 91 distal to the occluding portion 21 in
order to injure the tissue to facilitate electrical isolation of
the LAA 92. The ablation/compression portion 31 includes one or
more ablation/compression portion electrodes 32 to perform ablation
on the tissue. In another embodiment, the ablation portion may
include one or more electrodes or other elements 32 that enable
laser therapy or electroporation to isolate tissue at the left
atrial appendage ostium 91, or may use ultrasound to deliver
ablation energy to the tissue.
[0066] The anchoring portion 41 is deployed deep within the LAA 92,
i.e., distally beyond the ablation/compression portion 31, with
anchoring portion tines 43 and anchoring portion electrodes 42 to
help guide the device into the LAA 92.
[0067] FIG. 3 shows an exemplary method for sequentially deploying
the components of the device 8 within the left atrial appendage 92.
In this embodiment, the deployment sheath 11 with deployment sheath
electrodes 12 may be used, first, to deploy the anchoring portion
41 of the device 8 into the deep aspects of the LAA 92. In the
exemplary embodiment shown, the anchoring portion 41 may be a
spiral catheter that may be enlarged to enable optimal contact and
force against the cardiac tissue. The anchoring portion tines 43
are used to prevent embolization and anchoring portion electrodes
42 are used for positioning and deployment of the anchoring portion
41. In some embodiments, the anchoring portion electrodes 42 may be
used to verify LAA 92 electrical isolation, e.g., by a controller
(not shown) communicating with the electrodes 42. In another
embodiment, the anchoring portion electrodes 42 may also deliver
energy to ablate cardiac tissue, e.g., via a power source operated
via the controller.
[0068] In this embodiment, a distal portion of the deployment
sheath 11 may have a predetermined shape, e.g., biased to include a
bend or angle, e.g., an acute angle not more than ninety degrees,
proximal to the electrodes 12 to facilitate device deployment. In
another embodiment, the bend may be able to rotate freely along the
axis of the deployment sheath 11. In yet another embodiment, the
angle may be controlled to a certain angle, e.g., using a steering
element (not shown) extending from the distal portion to an
actuator on the proximal end of the sheath, and/or the rotation may
be controlled e.g., by rotating the proximal end of the deployment
sheath 11 from outside the patient's body.
[0069] FIG. 4 is a cross-sectional view showing the device 8
deployed within the LAA looking at the ostium of the LAA en face.
The ablation/compression portion electrodes 32 are aligned along
the LAA ostium 91. In one embodiment, the electrodes may be
configured to deliver RF energy between the electrode and a
grounding pad (e.g., in a uni-polar configuration). In addition or
alternatively, RF energy may be delivered between two different
electrodes (e.g., in a bi-polar configuration). By performing
numerous ablations between one electrode and the ground; as well as
each electrode to its closest neighbors, the LAA may be
successfully electrically isolated. The closest neighboring
electrode may be the electrode next along the device length, or
against the closest electrode in the neighboring loop.
[0070] The ablation/compression portion 31 may be spring loaded,
e.g., to a diameter or other cross-section larger than the LAA,
such that it may be released to create radial force against the LAA
ostium 91. In another embodiment, the ablation/compression portion
31 may have an inner cable or plunger (not shown) to enlarge the
spiral/coils in order to control the size and resulting radial
force. After the ablation/compression portion 31 is successfully
positioned in the LAA 92, the occluding portion 21 may then be
positioned to form a spiral pyramid to completely occlude the LAA
92 from the left atrium.
[0071] Turning to FIGS. 5-6, another embodiment of a device 8' is
shown for electrical isolation of a left atrial appendage 92. In
this embodiment, the device 8' includes an expanding portion 61,
e.g., made of nitinol or other metal, such that the self-expanding
portion 61 self-expands in blood, similar to a sponge. In one
embodiment, the expanding portion 61 has an elongate member 68
extending from a distal end of the expanding portion 61. The
elongate member 68 may have one or more guiding electrodes 62,
e.g., a plurality of electrodes spaced apart along its length. In
addition, one or more ablation electrodes 65, e.g., a plurality of
spaced-apart electrodes, may also be provided on the elongate
member 68. The elongate member 68 may be biased to coil around a
distal portion of a deployment sheath 11 used to deliver and/or
deploy the device 8'. The ablation electrodes 65 may also function
as guiding electrodes 62 and are not mutually exclusive in any
embodiment.
[0072] In this embodiment, the device 8' may be advanced into the
deployment sheath 11, e.g., through a lumen of the deployment
sheath 11 previously positioned within the left atrium 90. Once
inside the left atrium 90, the device 8' may be advanced such that
the elongate member 68 with guiding electrodes 62 extends out of
the tip of the deployment sheath 11, e.g., as shown in FIG. 5. The
elongate member 68 may automatically coil in front of the
self-expanding portion 61 to help deployment into the LAA 92. In
another embodiment, the elongate member 68 may automatically coil
around the deployment sheath 11 once deployed. By surrounding the
sheath 11 with electrodes 62, the deployment sheath 11 may be
safely advanced into the LAA 92, e.g., using external imaging
and/or mapping, similar to other embodiments herein. In addition,
the guiding electrodes 62 may be seen on a mapping system to make
sure the device 8' and deployment sheath 11 have the correct
orientation when advanced into the LAA 92.
[0073] In one embodiment, the expanding portion 61 is
self-expanding, e.g., formed from superelastic and/or
temperature-activated material that is biased to assume the coil
shape when deployed from the sheath 11 within the left atrium 90.
In another embodiment, the expanding portion 61 may be expanded
using to an external force, including inflating a balloon,
delivering current through the material, or using a
plunger/mechanical mechanism (not shown).
[0074] Once the deployment sheath 11 is advanced into the LAA 92,
the guiding electrodes 62 may enlarge, uncoil, or change shape to
facilitate contact with the LAA 92 tissue. RF energy may then be
delivered through the guiding electrodes 62 to electrically isolate
the LAA 92. Next, the deployment sheath 11 may be withdrawn,
exposing the expanding member 61 within the LAA 92, e.g., within
the ostium 91. The expanding member 61 may then expand and
completely occlude the LAA 92 from the rest of the left atrium 90.
The expanding member 61 then locks the device 8' within the LAA
92.
[0075] Optionally, the expanding member 61 may include material to
facilitate endothelialization. In another embodiment, a cover may
be provided proximal to the expanding member 61 to completely
occlude the LAA 92 from the LA 90. The expanding member 61 may be
designed to deliver radial force to isolate the LAA 92 through
compression, e.g., similar to other embodiments herein. In another
embodiment, a covering disc 69 (not shown, see FIG. 6) is
positioned proximal to the expanding member 61 to deliver radial
force to isolate the LAA 92.
[0076] The covering disc may also occlude the LAA 92 from the rest
of the LA 90. A useful aspect of the device 8' shown in FIG. 5 is
that the device 8' is deployed within the LA 90 such the device 8'
makes a conformational change within the LA 90 before it is
advanced into the LAA 92. Current LAA devices are generally
designed to have the device deployed directly into the LAA 92. A
unique aspect of the device 8' is that it is deployed into the LA
90 and then changes shape before being advanced into the LAA 92.
This confirmation change may be easily performed within the open
space of the LA 90 without being confined to the LAA 92 structure,
which is known to be quite friable. By enabling the device 8' to be
deployed and change shape within the LA 90, new opportunities are
available to positioning the device 8'. Similar to a
ship-in-a-bottle, the device 8' may be prepared in the LA 90 and
then advanced and deployed into the LAA 92.
[0077] FIG. 6 is a cross-sectional view of a distal end of the
deployment sheath 11 including the device 8' positioned within a
lumen of the deployment sheath 11. In this embodiment, the covering
disc 69, the enlarging member 61, the elongate member 68 with
guiding electrodes 62 are all positioned sequentially within the
lumen of the deployment sheath 11. As the device 8' is advanced,
the elongate member 68 initially is deployed and coils. The
elongate member 68 includes electrodes 62 to guide the deployment
sheath 11 into the LAA ostium 91. The elongate member 68 may then
bend into a certain pre-specified structure. Similar to a
ship-in-a-bottle, the elongate member 68 may assume a complex shape
to facilitate the deployment sheath 11 into the LAA 92, position
the device 8' optimally, expand to deliver radial force against the
ostium of the LAA 91, and/or deliver RF energy. The expanding
member 61 may then further lock the device 8' into place.
[0078] Turning to FIG. 7, another embodiment of a device 8'' is
shown for electrical isolation of a left atrial appendage 92
generally similar to other embodiments herein. In this embodiment,
the device 8'' includes an elongate member 68 including one or more
electrodes 62. e.g., a plurality of spaced-apart electrodes similar
to other embodiments herein. After leaving the deployment sheath
(not shown), the elongate member 68 coils into a predetermined
shape, e.g., a spherical shape, within the LAA 92. By having the
elongate member 68 lined by electrodes 62 into a spherical
structure, any orientation of the device 8'' may be used isolate
the LAA 92 electrically.
[0079] Turning to FIG. 8, another embodiment of a device 8''' is
shown for electrical isolation of a left atrial appendage 92. In
this embodiment, the device 8''' includes an expandable member 71
carrying one or more electrodes 72, e.g., a plurality of spaced
apart electrodes. These electrodes 72 may be used to guide
deployment as well ablate cardiac tissue to isolate the LAA 92,
e.g., similar to other embodiments herein. The ablation may be
performed utilizing ultrashort high voltage ablation, e.g., to
induce electroporation to induce LAA 92 electrical isolation. The
ablation electrodes 72 may be connected to the deployment sheath 11
through one or more connectors 73, which transmit electrical
signals from an external controller (not shown) to the electrodes
72.
[0080] FIG. 9 is a schematic illustration of an exemplary
embodiment of an electrical connection to the device 8''' shown in
FIG. 8. The closure device 71 is transported through a lumen of the
deployment sheath 11, e.g., previously introduced into the left
atrium, similar to other embodiments herein. The closure device 71
maybe deployed using a plunger 78, e.g., movable relative to the
sheath 11, that includes one or more connectors 75 to transmit
electricity from the external controller.
[0081] The plunger 78 and closure device 71 may include one or more
cooperating and/or detachable connectors for releasing the closure
device 71 from the plunger 78 after deployment. For example, in an
exemplary embodiment, the plunger 78 and closure device 71 may
include mating threads such that the plunger 78 may be rotated to
disconnect the closure device 71. After the plunger 78 and
connectors 75 are disconnected and withdrawn, a cap 79 covers the
connection site between the connectors 75 and the closure device
71.
[0082] Turning to FIGS. 10 and 13-16, another embodiment of a
deployable device 8G is shown including an elongate spiraling
member 110 carrying one or more batteries 117, a controller or
processor 120, and a cover 130, e.g., formed from Nitinol or other
elastic material. As shown, a delivery sheath 11 may be used to
deliver the device 8G, e.g., to sequentially deploy the components
to isolate the LAA 92. Optionally, the spiraling member 110 may
include one or more tines 113, e.g., to help stabilizing the device
8G within the LAA 92. In the embodiment shown, the spiraling member
110 may carry a plurality of battery subunits 117 connected to one
another by connectors or electrodes 112, e.g., in series. The
connectors 112 may be flexible to allow the spiraling member 110 to
spiral or fold upon deployment. In other embodiments, the
connectors 112 may include electrodes, which may be configured to
be visualized on a mapping system. In addition, the connectors 112
may be coupled to the processor 120, e.g., to deliver ablation
energy to electrically isolate the left atrial appendage, similar
to other embodiments herein. Optionally, the connectors 112 may
also measure local electrical activity. For example, connectors 112
in the proximal portion of the LAA 92 may deliver ablation energy,
while connectors 112 in the distal portion of the LAA 92 may be
used to identify that the LAA 92 has been successfully electrically
isolated. Optionally, some of the distal connectors 112 may also
deliver electrical energy to facilitate adherence or attachment to
tissue. The energy may be delivered while the connectors 112 are in
contact with the LAA 92, thereby making the tissue `stick` to the
connectors 112. In another embodiment, the created heat may be used
to cause a confirmation change in the tines 113 to have better
contract or even screw into the LAA 92.
[0083] The spiraling member 110 may also house the battery units
117 for the device 8G. In general, the battery units 117 may be
made similar to components that power other implantable devices,
including but not limited to lithium-metal, lithium-ion, silver
oxide, lithium iodide, and lithium/manganese dioxide. In some
embodiments, the batteries are firm; in other embodiments the
batteries are flexible to facilitate deployment. In other
embodiments, the spiraling member 110 is able to create electrical
energy from heart movement. In other embodiments, the device 8G may
be powered by ultrasound or electromagnetic energy.
[0084] In some embodiments, the spiraling member 110 includes a
series of repeating battery subunits 117 that are flexible.
However, not all batteries are flexible. Therefore, in order for
the battery subunits 117 to change shape to fit and/or attach
within the LAA 92, the battery subunits 117 may not be flexible but
the connectors 112 are flexible. In some embodiments of the device
8G, the battery portion of the elongate member 110 includes at
least two or more similar repeating subunits 117. These battery
subunits 117 are connected by one or more connectors 112. The
connector 112 enables a hinge point that allows the battery
subunits 117 to change orientation for deployment within the LAA
92.
[0085] The device 8G may be deployed from the distal end of the
delivery sheath 11 using a plunger 140, e.g., movable within a
lumen of the sheath 11. In some embodiments, the plunger 140 may
include inner connecting wires (not shown), e.g., coupled to the
connectors 112 until the device 8G is released. In the exemplary
embodiment shown, the plunger 140 on the distal end includes a
screw 122 that may be turned to release the plunger 140 from the
rest of the device 8G, although it will be appreciated that other
releasable connectors may be used, e.g., similar to other
embodiments herein.
[0086] In some embodiments, the device 8G includes a cover portion
130 designed to prevent thrombus from leaving the LAA 92. This
cover portion 130 may be configured to enclose most or all of the
device 8G within the LAA 92, e.g., expand across the ostium 91 of
the LAA 92, similar to other embodiments herein. Any blood clots
that form within the LAA 92 are then trapped within the LAA 92 and
cannot embolize. The cover portion 130 may include one or more
sensors that help measure left atrial pressure or physical
movement.
[0087] Optionally, the cover portion 130 may also include one or
more pacing electrodes 132. The pacing electrode(s) 132 enable the
device 8G to sense and pace the heart even if the LAA 92 is
electrically isolated. For example, the cover portion 130 may be
designed to extend beyond the ostium 91 of the LAA 92 to contact
atrial tissue within the main chamber of the left atrium 90.
Therefore, when the cover portion 130 covers the LAA 92, the pacing
electrodes 132 may contact atrial tissue outside the LAA 92. These
pacing electrode(s) 132 may be a few millimeters away from the
ostium 91 of the LAA 92 or extend several millimeters away from the
ostium 91 of the LAA 92. This enables the proceduralist to freely
electrically isolate the LAA 92 without concern that the device 8G
will not be able to sense and pace the heart. In some embodiments,
the cover 130 is able to freely rotate relative to the processor
120. This enables the cover 130 to completely close off the LAA 92.
In addition, this enables the cover 130 to be pulled back and
rotated to reposition the pacing electrodes (132). This may be done
if the pacing electrodes (132) do not have adequate sensing and
capture parameters to adequately sense and pace the heart,
respectively. In some embodiments, the pacing electrodes 132 extend
outward from the cover portion 130 to facilitate good tissue
contact.
[0088] FIG. 11 shows a simplified functional block diagram of one
embodiment of the device 8G. The components include the control
processor 120, battery component 117, memory component 250, pacing
electrodes 132, implantation electrodes 142, various sensors 231,
and a telemetry interface 257. The control processor 120 receives
input information from various components in order to determine the
function of the different components to treat the patient. The
pacing electrodes 132 are used to sense and pace the heart. The
pacing electrodes 132 are coupled to pacing circuitry 255 that is
coupled to the control processor 120.
[0089] Optionally, the device 8G may include one or more
implantation electrodes 142, which may visualized by a mapping
system in order to help deploy the device 8G within the LAA 92,
similar to other embodiments herein. In addition, optionally, the
implantation electrodes 142 may be used to deliver electrical or
electroporation energy in order to electrically isolate the LAA 92.
In other embodiments, the implantation electrodes 142 may deliver
energy to help attach the electrodes 142 to LAA 92 tissue to
prevent device 8G embolization.
[0090] The processor 120 may also be connected to one or more
sensors 231. In one embodiment, the sensors include a three-axis
accelerometer. Signals from the three-axis accelerometer may be
used by the processor 120 to detect patient activity in the
presence of cardiac motion. Alternative sensors 231 may include
vibration or movement sensing abilities, which may sense sound or
vibrations, e.g., to correlate with valve closure. By determining
valve closure, the device 8G may determine what the ventricle of
the heart is doing. In another embodiment, one or more temperature
and/or movement/accelerometer sensors may be provided that may be
coupled to the processor 120 to determine if the patient is
exerting or moving in order to determine the pacing rate of the
device 8G.
[0091] In another embodiment, the device 8G may include one or more
sensors 231 that correlate with the blood pressure within the left
atrium 90. These sensor(s) 231 may help identify a heart failure
admission similar to the CardioMEMs device. These sensor(s) 231 may
also be used to optimize medical therapy. In another embodiment,
various measurements between electrodes are used to guide device 8G
therapy. Both near-field and far-field electrical activity may be
used to determine atrial and ventricular activity as well as
diagnose conduction abnormalities.
[0092] The pacing circuitry 55 connects to pacing electrodes 132 to
the control processor 120. These connections allow for multiple
capacities to sense electrical activity (such as myocardial
depolarizations), deliver pacing stimulations, and/or deliver
defibrillation or cardioversion shocks. The control processor 120
may be connected to a telemetry interface 257. The telemetry
interface 257 may wirelessly send and/or receive data from an
external programmer 262, which may be coupled to a display module
264 in order to facilitate communication between the control
processor 120 and other aspects of the system external to the
patient.
[0093] Turning to FIG. 12, another exemplary embodiment of a
leadless pacemaker device 8H is shown that generally includes an
elongate member 110 carrying battery subunits 117, a processor 120,
and a cover 130, configured to be deployed sequentially from a
delivery sheath 11 for implantation within the left atrial
appendage (LAA) 92, generally similar to other embodiments herein.
In this embodiment, the battery subunits 117 are connected by
flexible connectors 112 that allow the batteries 117 to fold on
themselves. In this manner, the elongate member 110 carrying the
battery subunits 117 may be advanced out of the delivery sheath 11
and packed into the LAA 92. After the battery subunits 117 have
been advanced into the LAA 92, the processor 120 may be advanced
into the LAA 92. Finally, the cover portion 130 may be placed over
the ostium of the LAA 92. Optionally, in some embodiments, the
device 8H may include a separate anchor system (not shown) that
anchors the device 8H into the LAA 92. In another embodiment, the
connectors 112 are set to lock in place. By locking in place, the
entire structure is locked into position within the LAA 92. In some
embodiments, the elongate member 110 may include a plurality of
tines (not shown) that help attach the device 8H within the LAA
92.
[0094] Turning to FIGS. 13A and 16B, an exemplary method is shown
for deploying the device 8G shown in FIG. 10. Initially, as shown
in FIG. 13A, the distal end of the delivery sheath 11 may be
advanced to the ostium 91 of the left atrial appendage 92. The
plunger 140 is then moved relative to the delivery sheath 11, e.g.,
advanced while the delivery sheath 11 is held stationary. Moving on
to FIG. 13B, as the spiraling member 110 is deployed from the
delivery sheath 11, the spiraling member 110 coils around the
ostium 91 of the left atrial appendage 92. In some embodiments, the
delivery sheath 11 has a curved distal end. The distal end of the
delivery sheath 11 may help position the spiraling member 110
against the tissue of the left atrial appendage 92.
[0095] As shown, the spiraling member electrodes 112 may be evenly
spaced along the spiraling member 110. In other embodiments, the
spiraling member electrodes 112 are not evenly spaced. For example,
the spiraling member electrodes 112 may be more closely spaced
adjacent the distal end in order to have more electrodes located
near the proximal portion of the left atrial appendage 92, while
there may be just a few spiraling member electrodes 112 more
proximally which are then positioned deeper into the left atrial
appendage 92. This is because in some embodiments, as the plunger
140 is advanced, this action several loops of the spiraling member
110 to coil deeper and deeper into the left atrial appendage
92.
[0096] In some embodiments, a mechanism as used to dilate the
spiraling member 110. In one embodiment, the spiraling member 110
is placed entirely within the left atrial appendage 92, and then
the coils are released to create a radial force outwardly. This
radial force holds the spiraling member 110 firmly against left
atrial appendage 112 tissue. This mechanism includes a spring
mechanism that can be released as well as an inner cable (not
shown) that can be pulled or pushed to dilate/enlarge the coils of
the spiraling member 110.
[0097] Moving to FIG. 14A, the plunger 140 continues to be advanced
while the delivery sheath 11 remains stationary. The spiraling
member 110 continues to coil distally into the left atrial
appendage 92. Moving onto FIG. 14B, the processor component 120 is
advanced into the left atrial appendage 92. The processor component
120 may fit within an open central region of the spiraling member
110 after it's deployed. The connector component 110 may have
stabilizing tines (not shown) to position the processor component
120 within the center of the spiraling member 110.
[0098] Moving on to FIG. 15A, the spiraling member 110 has several
loops wrapping around the inside of the left atrial appendage 92.
In addition, as shown, the processor component 120 is located
within the spiraling member 110. In some embodiments, one or more
indicators may be provided on the proximal end of the delivery
sheath 11 located outside of the body (not shown), e.g., to
indicate that the spiraling member 110 and processor component 120
should not be located entirely within the left atrial appendage 92.
The deliver sheath 11 may then be withdrawn while the plunger 140
is fixed.
[0099] Moving to FIG. 15B, by withdrawing the deliver sheath 11
over the plunger 140, the Nitinol cover 130 is released. The
Nitinol cover 130 is designed to self-expand. This causes the
Nitinol cover 130 to cover the ostium 91 of the left atrial
appendage 92. This Nitinol cover 130 may substantially occlude or
otherwise isolate the left atrial appendage 92 from the rest of the
left atrium (not shown).
[0100] Moving to FIG. 16A, the device 8G is now completely located
within the left atrial appendage 92. The delivery sheath 11 may be
withdrawn to provide space between the delivery sheath 11 and the
device 8G. The plunger 140 may now be withdrawn to confirm the
device 8G is firmly positioned within the left atrial appendage 92.
This is a `tug test` to verify the device is unlikely to dislodge
and embolize.
[0101] Energy may then be delivered to the optimally positioned
spiral member electrodes 112. This energy may ablate the proximal
portion of the left atrial appendage 92 tissue to electrically
isolate the left atrial appendage 92. More distal spiral member
electrodes 112 may be used to monitor electrical activity from the
left atrial appendage 92 to verify the left atrial appendage 92 has
been electrically isolated.
[0102] Moving to FIG. 16B, the plunger 140 may then be rotated or
otherwise manipulated to release the device 8G. For example, as
shown, rotation spins the screw 122 to release the plunger 140 from
the device 8G. The plunger 140 may then be withdrawn. The distal
end of the plunger 140 includes connecting electrodes 125. These
connecting electrodes 125 connect the inner wires within the
plunger 140 to electrodes within the connector component 120. Once
the plunger 140 leaves the Nitinol cover 130, the Nitinol cover 130
may have a self-closing valve (not shown) to completely close off
the device 8G.
[0103] Turning to FIGS. 17A-19B, another embodiment of a device 8J
is shown for electrical isolation of a left atrial appendage 92
generally similar to the device 8H shown in FIG. 12 with several
differences. In this embodiment, instead of a connector component
122 described in FIG. 12, the device 8J includes a processor 170
electrically connected to the spiraling member electrodes 112,
e.g., located between a spiraling member 100 carrying the
electrodes 112 and a compression portion 180. In addition, the
spiraling member 110 may be deployed from the distal end of the
delivery sheath 11 whereupon the spiraling member 110 may
automatically coil towards a preset shape. Once coiled inside of
the left atrium 90, the sheath 11 may then be safely advanced
towards the left atrium appendage 92.
[0104] Moving on to FIG. 17B, the device 8J may then be advanced
deep into the left atrial appendage 92. The depth of the device 8J
may be determined and verified using a mapping system (not shown),
e.g., connected to the spiraling member electrodes 112 such that
the mapping system receives signals from the electrodes 112 that
may be analyzed to confirm the position of the spiraling member
110. The electrodes 112 may be coupled to the mapping system via
wires that extend through the delivery sheath 11; alternatively,
the signals may be sent wirelessly, e.g., via a wireless
communications interface (not shown) communicating with the
processor 170. A battery (not shown) for the processor 170 may be
stored in the processor portion, e.g., mounted on a substrate (also
not shown) that carries the processor 170. In another embodiment,
the spiraling member 110 has energy stored within this segment. The
spiraling member 110 may therefore also function as a battery. Once
the spiraling member 110 and sheath 11 are optimally placed within
the left atrial appendage 92, the spiraling member 110 may be
enlarged to stabilize within the left atrial appendage 92.
[0105] Moving on to FIG. 18A, once the spiraling member 110 is
properly positioned, the delivery sheath 11 may be withdrawn,
thereby releasing the processor 170 within the left atrial
appendage 92. In some embodiments, the processor 170 itself may
coil within the left atrial appendage 92 or the processor 170 may
maintain its original linear orientation. Moving to FIG. 18B, as
the delivery sheath 11 is further withdrawn, processor stabilizing
rods 172 may be deployed, e.g., that expand radially outwardly from
the processor 170 to help position the processor 170 within the
left atrial appendage 92.
[0106] Now moving to FIG. 19A, as the delivery sheath 11 is further
withdrawn, the compression portion 180 is released, e.g., by
plunger 140, which may cause the compression portion 180 to
resiliently expand to at least partially seal the ostium 91 of the
LAA 92. The compression portion 180 is designed to deliver radial
force against tissue within the left atrial appendage 92 to
electrically isolate the left atrial appendage 92. The spiraling
member electrodes 112 may be used to verify electrical isolation.
These signals may be sent via the processor 170 through wireless
connection or coupled through the plunger 140. The processor 170
may also be charged wirelessly from outside the body, e.g., using
an inductive charging system (not shown). In some circumstances,
electrodes (not shown) may be attached to or otherwise provided on
the compression portion 180, e.g., configured to deliver energy to
electrically isolate the left atrial appendage 92, e.g., if
compression alone does not isolate the left atrial appendage
92.
[0107] Moving on to FIG. 19B, the plunger 140 may be rotated or
otherwise decoupled to free the plunger 140 from the rest of the
device. The delivery sheath 11 and plunger 140 may then be removed
from the body. As can be seen in this figure, sometimes the
processor stabilizing rods 172 are oriented in a different way to
optimally position the device within the left atrial appendage
92.
[0108] Optionally, the processor 170 may continue to measure one or
more patient characteristics based on electrical signals from the
electrodes 112, e.g., to identify heart rate, recurrence of atrial
fibrillation, or other arrhythmias. The electrodes 112 (or other
electrodes) on the device 8J may measure both local electrical
signals to identify electrical activity of the left atrial
appendage 92 as well as far-field signals of the left atrium and
ventricular activation. By measuring the interval between the
ventricular signals, the device 8J may identify atrial
fibrillation. The processor 170 may send these signals to devices
outside of the body for medical intervention.
[0109] In another embodiment, the device 8J may identify if local
electrical reconnection has occurred within the left atrial
appendage 92. In yet another embodiment, the device 8J may measure
left atrial pressure, oxygen saturation, cardiac output, and
patient activity. In addition or alternatively, an accelerometer
may be included on the device 8J, and the device 8J may measure
heart rate and patient movement to determine if the heart rate is
congruent with patient activity.
[0110] Turning to FIGS. 20-21, another exemplary embodiment of the
device 8K is shown that includes a plurality of repeating subunits
301-311 connected sequentially to one another by connectors
301c-311c. Although, the device 8K includes eleven subunits
301-311, it will be appreciated that the device 8K may include any
desired number of subunits. As shown, the subunits include a first
subset that include battery subunits to provide a battery 117 for
the device 8K, e.g., the distal two repeating subunits 301-302, as
shown in FIG. 20. The connectors 301c-311c connecting the subunits
301-311 may be flexible to allow the subunits 301-311 to move in a
desired manner, e.g., during advancement through the delivery
sheath 11, yet bias the device 8K to adopt a desired shape when
deployed. For example, the connectors 301c-311c may provide hinge
points that permit the subunits 301-311 to fold on themselves to
provide a desired expanded configuration. Optionally, the
connectors 301c-311c may include one or more tines (not shown),
electrodes (not shown), or other components to facilitate
deployment, e.g., similar to other embodiments described elsewhere
herein.
[0111] Turning to FIGS. 21A-21B, an exemplary method is shown for
deploying the device 8K when the device 8K is advanced out of the
delivery sheath 11. Initially, as shown in FIG. 21A, the distal
subunit 301 is deployed from the delivery sheath 11, whereupon the
connector 301c provides a hinge point, e.g., biased to cause the
distal subunit 301 to have an orientation change to the adjacent
subunit 302. For example, the connector 301c may be biased to a "U"
or other shape, e.g., to cause the distal subunit 301 to rotate or
otherwise translate one hundred eighty degrees relative to the
second subunit 302. Moving onto FIG. 21B, as the device 8K is
further advanced out of the delivery sheath 11, the subunits
302-311 are deployed sequentially, and automatically fold relative
to the adjacent subunits into a designed orientation. In some
embodiments, the connectors 302c-311c of the device 8K are
configured to automatically orient the subunits 302-311 as the
device 8K emerges from the delivery sheath 11.
[0112] In other embodiments, an external force may be used to force
the change in orientation. For example, the connectors 301c-311c
may have a hinge type joint where the degrees of freedom are
designed to fold the device 8K into the pre-designed
orientation.
[0113] FIG. 22 demonstrates an exemplary expanded configuration
where the subunits 301-311 orient themselves into a structure
depicted, e.g., where the subunits 301-311 are aligned axially
adjacent one another with the connectors 301c-311c alternating
between opposite ends of the expanded structure. In this
embodiment, the subunits 301-311 are relatively fixed; while the
connectors 301c-311c enable the device 8K to fold into the depicted
structure.
[0114] FIG. 23 demonstrates another exemplary expanded
configuration of the device 8K where the subunits 301-311 extend
radially outwardly from a central region, to provide a
conformational change once positioned inside the LAA (not figured).
In this example, the connectors 303c, 305c, 307c, 309c, and 311c
are designed to expand along their hinge joint, while other
connectors 301c, 302c, 304c, 306c, 308c, and 310c are designed to
maintain a closed position.
[0115] Optionally, one or more tines and/or leads (not shown) may
be provided on the connectors 304c, 306c, 308c, and 310c that make
contact against the LAA (not shown), e.g., to prevent embolization
or to confirm contact through electrical signals, similar to other
embodiments herein. In other embodiments, the connectors 304c,
306c, 308c, and 310c may include electrodes (not shown) that may be
used for visualization, cardiac pacing, tissue heating (for tissue
`sticking`), ablating, and/or electroporation, as previously
described elsewhere herein.
[0116] Alternatively, the example shown in FIG. 23 may represent
the configuration of the device 8K wherein initially deployed
within the left atrium, e.g., when fully deployed from the sheath
11. Features such as tines, hooks, loops, or the like (not shown)
on the distal portion of the connectors 304c, 306c, 308c, 310c may
be manipulated to narrow the device profile to the configuration
presented in FIG. 22 for advancement into the LAA 92.
[0117] For example, with reference to FIG. 24, the device 8K may be
deployed within the left atrium 90 in the configuration shown in
FIG. 23 and then folded or otherwise constrained into the
configuration shown in FIG. 22, whereupon the folded device 8K may
be advanced into the LAA 92, e.g., over guide 330. In this
embodiment, the delivery sheath 11 has been advanced into the left
atrium 90 through the interatrial septum 94. Once inside the left
atrium 90, the elongate device 8G may be advanced to create the
desired shape within the left atrium 90, e.g., the deployed
configuration shown in FIG. 23. Similar to a ship-in-a-bottle, the
device 8K may be manipulated to take on a conformational change
within the left atrium 90 to take on a desired shape or structure,
e.g., that shown in FIGS. 22 and 24. The conformed device 8K may
then be advanced into the LAA 92. Once inside the LAA 92, the
device 8K may take on a second conformational change to deploy the
device 8K into the LAA 92, e.g., by releasing the device 8K to
allow the subunits to resiliently return towards the configuration
shown in FIG. 23. The second conformational change locks the device
8G in place within the LAA 92.
[0118] In the embodiment depicted in FIG. 24, an elongate guide
member 330 is provided that is configured to pass through a
delivery lumen of the delivery sheath 11, the proximal connector
311c (not shown), and the proximal subunit 311. In exemplary
embodiments, the elongate guide member 330 may be a wire or may be
a steerable catheter. In other embodiments, the elongate guide
member 330 may be similar to a pigtail catheter with an inner lumen
that allows an inner wire to advance through the elongate guide
member 330. For example, a distal portion of the elongate guide
member 330 may be exposed from the sheath 11 and advanced or
otherwise directed into the LAA 92, and then the device 8K may be
advanced over the elongate guide member 330 in order to position
the device 8K optimally within the LAA 92. In some embodiments, the
elongate guide member 330 passes through an inner lumen of the
connector 311c and subunit 311 or connector 301c.
[0119] In some embodiments, at least the distal portion of the
elongate guide member 330 may have a substantially square or other
non-circular cross-section. By being square, the elongate guide 330
may be spun to deliver force to the device 8G. For example, if the
elongate guide member 330 and an inner lumen of the subunit 311
have a similar cross-section, rotating the elongate guide member
330 about its longitudinal axis may be used to spin the subunit
311. This spinning motion may be designed to expand the device 8K
into a desired expanded configuration, for example, the
configuration shown in FIG. 23.
[0120] In other embodiments, the elongate guide member 330 may
include a balloon or other expanded member on the distal portion
that may be inflated or otherwise expanded to expand or otherwise
deploy the device 8K once in place in the LAA 92. The balloon
portion may be asymmetric in order to expand the distal or proximal
connectors. In other embodiments, the elongate guide member 330 may
also include docking features (not pictured) to interface with the
distal portion of the device 8K, e.g., providing an additional
landmark for visibility during device placement.
[0121] Alternatively, other mechanisms may be provided to orient
the device 8K, e.g., including one or more of springs, ratchets,
Nitinol or other elastic material, temperature-activated materials,
and/or through electricity. As an example, FIG. 33 shows the device
8K in the delivery configuration, with the articulating members of
the device 8K including springs and micro-ratchets. Deployment of
the FIG. 33 device into the atrium, advancement into the LAA, and
further expansion in the LAA are shown in FIGS. 34A-C,
respectively. In some embodiments, one of the connectors used to
orient the device 8K may also serve as an atraumatic lead in the
tip of the delivery sheath 11.
[0122] In other embodiments, a string or wire may run through the
device 8K, e.g., as shown in FIG. 35A where the device has been
deployed in the left atrium. As shown in FIG. 35B, the string may
be pulled or otherwise actuated from outside the patient, e.g.,
using an actuator on the proximal end (not shown) of the sheath 11,
to force the subunits to collapse as or after the device 8K is
advanced out of the delivery sheath 11. Once the device 8G is
positioned within the LAA 92, the string may be relaxed. The
relaxation may then cause certain connectors (or all the
connectors) to elongate in prescribed directions and/or force to
lock the device 8K within the LAA 92. For example, once the string
is relaxed, the device 8K may expand automatically through a
variety of methods, including but not limited to a spring
mechanism, Nitinol, temperature-activated materials, and/or
electrical energy. Optionally, the string may be tightened to
collapse the device 8K in a desired manner, e.g., into the
configuration as illustrated in FIG. 22. As exemplified in FIGS.
36A-36D, repositioning within the LAA 92 while in the narrowed
configuration of FIG. 22 may be repeated as needed, by relaxing the
string to expand the device 8G (FIG. 36A), verifying the position,
and tightening the string to reposition as necessary (FIGS. 36
B-C). After the string is relaxed and placement within the LAA 92
is confirmed (FIG. 36D), the string may then be cut or otherwise
separated and withdrawn from the device 8K to leave the device 8K
in place within the LAA 92.
[0123] In another embodiment, e.g., as illustrated in FIG. 30A, a
balloon may be provided on a distal tip (not shown) of the elongate
guide member 330, which may be filled with saline and/or other
inflation media to expand the subunits 301-311 of the device 8K in
a desired manner, e.g., opening the proximal connectors to assume
the shape in FIG. 23, creating contact with the distal portion of
the device 8K and the LAA 92. As shown in FIG. 30B, if the device
8K needs to be advanced into the LAA 92, the balloon may be
inflated within the proximal connectors, thereby expanding the
proximal profile of the device 8K and narrowing the position of the
distal connectors. The balloon may then be collapsed, the device 8K
advanced further into the LAA 92, and the balloon inflated within
the distal connectors, e.g., as shown in FIG. 30C. In another
embodiment, features on the distal connectors remain captured by
the delivery system using a string method similar to that described
above, and are leveraged to collapse the device after balloon
expansion.
[0124] In another embodiment, the delivery sheath 11 may be used to
collapse the device 8K in a desired manner, e.g., as shown in FIGS.
31A-31D. In this embodiment, the distal tip 11b of the delivery
sheath 11 may include a plurality of axial slots 11c and one or
more circumferential strings, wires, or other filaments 11d coupled
to the subunits 301-311. The filament(s) 11d may be relaxed to
widen the sheath distal diameter, e.g., as shown in FIG. 31B, and
then the sheath 11 is advanced over the proximal connectors, as
shown in FIG. 13C. Once the proximal connectors and part of the
rigid subunits are captured, the circumferential filament 11d may
be tightened to collapse the distal tip 11c of the sheath 11 and
narrow the device profile, as shown in FIG. 31D, for introduction
into the LAA (not shown).
[0125] Turning to FIGS. 25A and 25B, an exemplary method is for
implanting the device 8K, i.e., deploying, introducing and
anchoring the device 8K within the LAA 92. Initially, the device
8K8G is advanced into the LAA 92 in a constrained condition, e.g.,
similar to the configuration shown in FIG. 22. Moving onto FIG.
25B, the device 8k may then be enlarged or otherwise deployed to
connect within the walls of the LAA 92, e.g., similar to the
configuration shown in FIG. 23. The device 8K may then undergo tug
testing from outside the patient's body to make sure the device 8K
is adequately fixed within the LAA 92, visually assessed using
fluoroscopy, echocardiography, or other visual mapping methods to
confirm device 8G shape and depth of position, and/or contact with
the LAA may be confirmed by electrical signal. If needed, the
device may be recaptured, repositioned, and then re-deployed, e.g.,
using any of the methods described elsewhere herein. In another
embodiment, if fixation is insufficient, the proximal hinges may be
further elongated or otherwise manipulated in order to widen the
angle between the rigid subunits, providing greater apposition to
the LAA 92.
[0126] Moving on to FIG. 26, once the device 8K is satisfactorily
deployed within the LAA 92, a cover or occluding portion 21 may be
deployed to cover the ostium of the LAA 92. The cover 21 may be
made out of a variety of materials. The cover 21, which may be
similar to cover 130 or any of the other embodiments described
elsewhere herein, is designed to cap the ostium of the LAA 92 and
prevent thrombus or clot that may form within the LAA 92 from
leaving the LAA 92. In some embodiments, the cover 21 includes one
or more pacing electrodes 132, e.g., located on the LAA 92 side of
the cover 21. These pacing electrodes 132 may be configured to
contact the wall of left atrium 90 outside of the LAA 92.
Therefore, if the LAA 92 is electrically isolated, the pacing
electrodes 132 are still able to sense and capture atrial tissue.
The pacing electrodes 132 may be single or bipolar electrodes. The
pacing electrodes 132 are therefore able to sense atrial
depolarizations and deliver pacing stimulations to pace the atrial
tissue. In some embodiments, atrial anti-tachycardia pacing (ATP)
may be delivered from one electrode 132 and sensed by other
electrodes. Therefore, pacing stimulations may be delivered at one
location; and distant electrodes are able to determine if the
pacing stimulations are capturing heart tissue. The ATP algorithm
may then change pacing strategies based on whether the pacing
stimulations are capturing the atria.
[0127] In some embodiments, the center of the cover 21 is deployed
first, followed by the outer circumference of the cover 21. In
other embodiments, the outer circumference is deployed first,
contact with ostium verified through methods described above, and
the remainder of the cover 21 deployed. If the leads in the cover
21 are unable to obtain sufficient contact with the ostium, the
cover 21 may be recovered into the delivery system, repositioned,
and redeployed.
[0128] Turning to FIGS. 32A and 32B, in other embodiments, the
cover 21 may include two regions, a first region 21a that caps the
ostium of the LAA and a middle member 21b that sits within the LAA.
In some embodiments, the middle member 21b may include one or more
temporary or permanent leads 21c for electrical isolation of the
LAA, e.g., as shown in FIG. 32B. The middle member 21b may be
deployed before the cap 21a to allow for electrical isolation
treatments to be conducted before the cap 21a is deployed. In some
embodiments, the cover 21 and middle member 21b may include one or
more channels through which the leads 21c used for electrical
isolation or materials for electroporation may be advanced and
removed. In other embodiments, the middle member 21b itself may be
composed of materials that may be utilize to complete established
isolation methods. Furthermore, in some embodiments, the middle
member 21b provides tension between the cover 21a and the remainder
of the device 8K implanted further in the LAA, ensuring apposition
between the cover 21a and the ostium of the LAA 92. In other
embodiments, the deployment of the cover 21a or middle member 21b
further widens the angle between the rigid subunits in the distal
portion of the device 8K.
[0129] Turning to FIGS. 27A and 27B, two different expanding
devices are shown that include a different number of subunits. FIG.
27A shows a device with seven (7) subunits 301-307, while FIG. 27B
shows a device with eleven (11) subunits 301-311. In either
embodiment (or any of the others wherein), the device may include
two or more subunits that provide a housing to contain the various
components previously described, e.g., a processor, battery,
communications interface, and the like. The subunits may take on
various lengths and sizes. For example, in the embodiments shown in
FIG. 21-FIG. 26, the subunits may have lengths longer than about
ten millimeters (10 mm) and less than about thirty millimeters (30
mm). The diameter of the subunits may be larger than about three
millimeters (3 mm) and less than about six millimeters (6 mm). In
some embodiments, the subunits are sized to be about twenty one
millimeters (21 mm) in length (+/-5 mm) and about four millimeters
(4 mm) in diameter (+/-1 mm).
[0130] Turning to FIG. 28, a flow diagram is shown illustrating an
exemplary method for implanting a device, such as the device 8K (or
any other devices herein). In step 401, access of the left atrium
is obtained. A delivery sheath is typically placed across from the
right atrium into the left atrium. In step 402, the device is
advanced into the left atrium. Moving to step 403, once part of the
device is located within the left atrium, and the device changes
shape (e.g., automatically upon deployment or upon being actuated).
The shape change may be described as a conformation change or a
configuration change. Moving to step 404, the conformed or
configured device may then be advanced into or near the left atrial
appendage. In step 405, the device may then undergo a second shape
change within or near the left atrial appendage (e.g., constrained
or otherwise manipulated into a smaller profile). This second shape
change may also be described as a second conformational or second
configuration change. In some embodiments, this second shape change
is utilized to keep the device within or near the left atrial
appendage. In step 406, the device may then be deployed within or
near the left atrial appendage. The delivery tools may then be
removed from the left atrium.
[0131] FIG. 29 is another flow diagram describing another exemplary
embodiment implanting any of the devices described herein. In step
411, trans-septal puncture is obtained. In step 412, the left
atrial appendage is electrically isolated. Electrical isolation may
be achieved through heating, freezing, laser energy, or
electroporation. Electrical isolation may be achieved through an
ablation catheter that is separate from the device that will be
deployed within or near the left atrial appendage. Therefore, in
one embodiment, an ablation catheter may be used to electrical
isolate the left atrial appendage. After the left atrial appendage
is electrically isolated, we move to step 413 where the device is
deployed within or near the left atrial appendage. In other
embodiments, the device that will be deployed into or near the left
atrial appendage achieves electrical isolation. Moving to step 414,
at least one electrode is positioned against the left atrium but
outside the left atrial appendage. In step 415, the device is
deployed to monitor and treat atrial arrhythmias by pacing from the
electrode positioned against the left atrium but outside the left
atrial appendage. In some embodiments, the device has at least two
electrodes spaced apart from each other against left atrial tissue
but outside the left atrial appendage. By having two electrodes
spaced apart, one electrode can delivery anti-tachycardia pacing
(ATP) while the second electrode can monitor for local electrical
activity to determine if the ATP pacing pulses are capturing at
least a section of atrial tissue.
[0132] In another embodiment, an electrode is placed deep into the
left atrial appendage. This electrode may be used to sense
electrical activity. For example, ventricular activity may be
determined. In another embodiment, high output pacing from an
electrode positioned near the left ventricle can be used to pace
the left ventricle. The device may deliver high-powered shocks or
defibrillations to convert both atrial and ventricular arrhythmias.
When delivering atrial cardioversions, these high powered pulses
should be synced to ventricular activity.
[0133] Further, in describing representative embodiments, the
specification may have presented the method and/or process as a
particular sequence of steps. However, to the extent that the
method or process does not rely on the particular order of steps
set forth herein, the method or process should not be limited to
the particular sequence of steps described. As one of ordinary
skill in the art would appreciate, other sequences of steps may be
possible. Therefore, the particular order of the steps set forth in
the specification should not be construed as limitations on the
claims.
[0134] While the invention is susceptible to various modifications,
and alternative forms, specific examples thereof have been shown in
the drawings and are herein described in detail. It should be
understood, however, that the invention is not to be limited to the
particular forms or methods disclosed, but to the contrary, the
invention is to cover all modifications, equivalents and
alternatives falling within the scope of the appended claims.
* * * * *