U.S. patent application number 17/105603 was filed with the patent office on 2021-05-27 for implantable medical devices for multi-chamber pacing.
The applicant listed for this patent is Medtronic, Inc.. Invention is credited to Andrea J. Asleson, Wade M. Demmer, Nathan A. Grenz, Ruth N. Klepfer, Alexander R. Mattson, Kevin Seifert, Zhongping Yang.
Application Number | 20210154477 17/105603 |
Document ID | / |
Family ID | 1000005386872 |
Filed Date | 2021-05-27 |
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United States Patent
Application |
20210154477 |
Kind Code |
A1 |
Asleson; Andrea J. ; et
al. |
May 27, 2021 |
IMPLANTABLE MEDICAL DEVICES FOR MULTI-CHAMBER PACING
Abstract
Systems, devices, and methods may be used to deliver and provide
cardiac pacing therapy to a patient. Leads or leadlets carrying one
or more left ventricular electrodes may be positioned in or near
the interventricular septum to sense and pace left ventricular
signals of the patient's heart. In one example, a leadlet including
one or more left ventricular electrodes may extend in the coronary
sinus from a leadless implantable medical device located in the
right atrium.
Inventors: |
Asleson; Andrea J.; (Maple
Grove, MN) ; Demmer; Wade M.; (Coon Rapids, MN)
; Grenz; Nathan A.; (North Oaks, MN) ; Klepfer;
Ruth N.; (St. Louis Park, MN) ; Mattson; Alexander
R.; (St. Paul, MN) ; Seifert; Kevin; (Forest
Lake, MN) ; Yang; Zhongping; (Woodbury, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Medtronic, Inc. |
Minneapolis |
MN |
US |
|
|
Family ID: |
1000005386872 |
Appl. No.: |
17/105603 |
Filed: |
November 26, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62940711 |
Nov 26, 2019 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61N 1/37512 20170801;
A61B 17/3468 20130101; A61N 1/056 20130101; A61N 2001/0578
20130101; A61N 1/0573 20130101; A61N 2001/0585 20130101; A61N
1/3684 20130101 |
International
Class: |
A61N 1/368 20060101
A61N001/368; A61N 1/05 20060101 A61N001/05; A61B 17/34 20060101
A61B017/34; A61N 1/375 20060101 A61N001/375 |
Claims
1. An implantable medical device comprising: a plurality of
electrodes comprising: a right atrial electrode positionable within
the right atrium to deliver cardiac therapy to or sense electrical
activity of the right atrium of the patient's heart; and at least
one left ventricular electrode positionable proximate the left
ventricle of the patient's heart to deliver cardiac therapy to or
sense electrical activity of the left ventricle of the patient's
heart; a housing extending from a proximal end region to a distal
end region, wherein the right atrial electrode is leadlessly
coupled to the proximal end region; a leadlet extending from a
proximal region to a distal region, wherein the proximal region is
coupled to the distal end region of the housing and the at least
one ventricular electrode is coupled to the distal region of the
leadlet, wherein the leadlet is configured to extend through the
coronary sinus ostium and into the coronary sinus or a coronary
vein of the patient's heart to position the least one left
ventricular electrode proximate the left ventricle of the patient's
heart; a therapy delivery circuit within the housing and operably
coupled to the plurality of electrodes to deliver cardiac therapy
to the patient's heart; a sensing circuit within the housing and
operably coupled to the plurality of electrodes to sense electrical
activity of the patient's heart; and a controller within the
housing and comprising processing circuitry operably coupled to the
therapy delivery circuit and the sensing circuit, the controller
configured to: monitor electrical activity using the processing
circuitry and one or more of the plurality of electrodes; and
delivering pacing therapy using the processing circuitry and one or
more of the plurality of electrodes.
2. The device of claim 1, wherein the at least one left ventricular
electrode is implantable into the left ventricular myocardium from
the coronary sinus proximal to the posterior vein of the patient's
heart.
3. The device of claim 1, wherein the at least one left ventricular
electrode is implantable into the anterior interventricular vein of
the patient's heart.
4. The device of claim 1, wherein the at least one left ventricular
electrode is implantable into the lateral vein of the patient's
heart.
5. The device of claim 1, wherein delivering pacing therapy
comprises utilizing field steering to avoid left atrial capture by
the at least one left ventricular electrode.
6. A method comprising: implanting a right atrial electrode in the
right atrial endocardium or in the right atrial myocardium of a
patient's heart, the right atrial electrode being leadlessly
coupled to a proximal end region of an implantable housing, wherein
processing circuitry is disposed in the housing and operably
coupled to the right atrial electrode; implanting at least one left
ventricular electrode through the coronary sinus ostium and into
the coronary sinus or a coronary vein of the patient's heart, the
at least one left ventricular electrode being coupled to a distal
region of a leadlet, a proximal region of the leadlet being coupled
to a distal end region of the implantable housing, wherein the
processing circuitry is operably coupled to the at least one left
ventricular electrode; monitoring electrical activity using the
processing circuitry and one or more of the right atrial electrode
and the at least one left ventricular electrode; and delivering
pacing therapy using the processing circuitry and at one or more of
the right atrial electrode and the at least one left ventricular
electrode.
7. The method of claim 6, wherein implanting the left ventricular
electrode comprises implanting the left ventricular electrode into
the left ventricular myocardium from the coronary sinus proximal to
the posterior vein of the patient's heart.
8. The method of claim 6, wherein implanting the left ventricular
electrode comprises implanting the left ventricular electrode into
the anterior interventricular vein of the patient's heart.
9. The method of claim 6, wherein implanting the left ventricular
electrode comprises implanting the left ventricular electrode into
the lateral vein of the patient's heart.
10. The method of claim 6, wherein delivering pacing therapy
comprises utilizing field steering to avoid left atrial capture by
the left ventricular electrode.
11. A method comprising: delivering a delivery catheter and a
penetration element disposed in the delivery catheter to the right
ventricular endocardium of the interventricular septal wall of a
patient's heart; puncturing the right ventricular endocardium using
the penetration element to form an opening through the right
ventricular endocardium and into the interventricular septal wall;
retracting the penetration element; advancing a distal portion of a
guide element through the delivery catheter and the opening and
into the interventricular septal wall to extend along the left
ventricular endocardial wall; and delivering a distal portion of an
implantable medical lead over the guide element to the left
ventricular myocardium to extend along the left ventricular
endocardial wall to position at least one left ventricular
electrode on the distal portion in the left ventricular
myocardium.
12. The method of claim 11, wherein the at least one left
ventricular electrode is positioned proximate to the left bundle
branch of the conduction system of the patient's heart.
13. The method of claim 11, further comprising implanting at least
one right ventricular electrode proximate to the right ventricular
endocardium, the at least one right ventricular electrode being
positioned proximal to the at least one left ventricular electrode
on the distal portion of the implantable medical lead.
14. The method of claim 13, further comprising: monitoring
electrical activity of at least one of the at least one right
ventricular electrode and the at least one left ventricular
electrode; and delivering pacing therapy using at least one of the
at least one right ventricular electrode and the at least one left
ventricular electrode.
15. The method of claim 14, wherein delivering pacing therapy
comprises delivering pacing pulses using the at least one left
ventricular electrode to the left bundle branch of the conduction
system of the patient's heart.
16. The method of claim 13, wherein the at least one left
ventricular electrode comprises a plurality of left ventricular
electrodes, wherein the at least one right ventricular electrode
comprises a plurality of right ventricular electrodes.
17. The method of claim 11, wherein the delivery catheter extends
from a proximal portion to a distal portion, wherein the distal
portion defines a curvature to position a distal end of the
catheter substantially flush to the right ventricular
endocardium.
18. The method of claim 11, wherein the guide element extends from
a proximal region to the distal region, wherein the distal region
comprises a distal curvature portion that curves when exiting the
delivery catheter into the interventricular septal wall so as to
deliver at least a region of the distal portion of the implantable
medical lead substantially parallel to the interventricular septal
wall in the left ventricular myocardium.
19. A system for delivering an implantable medical lead into the
interventricular septal wall and proximate the left ventricular
myocardium, the system comprising: a delivery catheter extending
from a proximal end region to a distal end region, the distal end
region positionable adjacent to the right ventricular endocardium
of the interventricular septal wall of a patient's heart; a
penetration element disposable in the delivery catheter to form an
opening through the right ventricular endocardium and into the
interventricular septal wall; and a guide element extending from a
proximal end region to a distal end region, the guide element
disposable in the delivery catheter to enter the interventricular
septal wall through the opening and to extend along the left
ventricular endocardial wall.
20. The system of claim 19, wherein the system further comprises an
implantable medical lead comprising at least one left ventricular
electrode and deliverable over the guide element to the left
ventricular myocardium to extend along the left ventricular
endocardial wall to position the at least one left ventricular
electrode in the left ventricular myocardium of the patient's
heart.
21. The system of claim 20, wherein the at least on left
ventricular electrode is positioned proximate to the left bundle
branch of the conduction system of the patient's heart.
22. The system of claim 20, where the implantable medical lead
further comprises at least one right ventricular electrode
positionable proximate to the right ventricular endocardium.
23. The system of claim 22, wherein the at least one left
ventricular electrode comprises a plurality of left ventricular
electrodes, wherein the at least one right ventricular electrode
comprises a plurality of right ventricular electrodes.
24. The system of claim 19, wherein the distal end region of the
delivery catheter defines a curvature to position a distal end of
the catheter substantially flush to the right ventricular
endocardium.
25. The system of claim 19, wherein the distal end region of the
guide element comprises a distal curvature portion that curves when
exiting the delivery catheter into the interventricular septal wall
so as to deliver at least a region of the distal portion of the
implantable medical lead substantially parallel to the
interventricular septal wall in the left ventricular myocardium.
Description
[0001] This application claims the benefit of U.S. Provisional
Patent Application. Ser. No. 62/940,711 entitled "Implantable
Medical Devices For Multi-Chamber Pacing" filed on Nov. 26, 2019,
which is incorporated herein by reference in its entirety.
[0002] The present technology is generally related to implantable
medical devices and, in particular, leadless implantable medical
devices and related uses.
SUMMARY
[0003] In one illustrative implantable medical device, the device
includes a plurality of electrodes. The plurality of electrodes may
include a right atrial electrode positionable within the right
atrium to deliver cardiac therapy to or sense electrical activity
of the right atrium of the patient's heart and at least one left
ventricular electrode positionable proximate the left ventricle of
the patient's heart. The device may further include a housing
extending from a proximal end region to a distal end region and the
right atrial electrode may be leadlessly coupled to the proximal
end region. The device may further include a leadlet extending from
a proximal region to a distal region, where the proximal region is
coupled to the distal end region of the housing and the at least
one ventricular electrode is coupled to the distal region of the
leadlet. Further, the leadlet may be configured to extend through
the coronary sinus ostium and into the coronary sinus or a coronary
vein of the patient's heart to position the least one left
ventricular electrode proximate the left ventricle of the patient's
heart. The device may further include a therapy delivery circuit
within the housing and operably coupled to the plurality of
electrodes to deliver cardiac therapy to the patient's heart and a
sensing circuit within the housing and operably coupled to the
plurality of electrodes to sense electrical activity of the
patient's heart. The device may further include a controller within
the housing and comprising processing circuitry operably coupled to
the therapy delivery circuit and the sensing circuit. The
controller may be configured to monitor electrical activity using
the processing circuitry and one or more of the plurality of
electrodes and delivering pacing therapy using the processing
circuitry and one or more of the plurality of electrodes.
[0004] In one illustrative method, the method may include
implanting a right atrial electrode in the right atrial endocardium
or in the right atrial myocardium of a patient's heart, the right
atrial electrode being leadlessly coupled to a proximal end region
of an implantable housing. The method may further include
implanting at least one left ventricular electrode through the
coronary sinus ostium and into the coronary sinus or a coronary
vein of the patient's heart, where the at least one left
ventricular electrode being coupled to a distal region of a leadlet
and a proximal region of the leadlet being coupled to a distal end
region of the implantable housing. Processing circuitry may be
located, positioned, or disposed, in the housing and operably
coupled to the right atrial electrode and the at least one left
ventricular electrode. The method may further include monitoring
electrical activity using the processing circuitry and one or more
of the right atrial electrode and the at least one left ventricular
electrode and delivering pacing therapy using the processing
circuitry and at one or more of the right atrial electrode and the
at least one left ventricular electrode.
[0005] In one illustrative method, the method may include
delivering a delivery catheter and a penetration element located,
positioned, or disposed, in the delivery catheter to the right
ventricular endocardium of the interventricular septal wall of a
patient's heart, puncturing the right ventricular endocardium using
the penetration element to form an opening through the right
ventricular endocardium and into the interventricular septal wall,
and retracting the penetration element. The method may further
include advancing a distal portion of a guide element through the
delivery catheter and the opening and into the interventricular
septal wall to extend along the left ventricular endocardial wall
and delivering a distal portion of an implantable medical lead over
the guide element to the left ventricular myocardium to extend
along the left ventricular endocardial wall to position at least
one left ventricular electrode on the distal portion in the left
ventricular myocardium.
[0006] In one illustrative system for delivering an implantable
medical lead into the interventricular septal wall and proximate
the left ventricular myocardium, the system may include a delivery
catheter extending from a proximal end region to a distal end
region, where the distal end region positionable adjacent to the
right ventricular endocardium of the interventricular septal wall
of a patient's heart. The system may further include a penetration
element locatable, positionable, or disposable, in the delivery
catheter to form an opening through the right ventricular
endocardium and into the interventricular septal wall and a guide
element extending from a proximal end region to a distal end
region. The guide element may be locatable, positionable, or
disposable, in the delivery catheter to enter the interventricular
septal wall through the opening and to extend along the left
ventricular endocardial wall.
[0007] The above summary is not intended to describe each
embodiment or every implementation of the present disclosure. A
more complete understanding will become apparent and appreciated by
referring to the following detailed description and claims taken in
conjunction with the accompanying drawings. In other words, these
and various other features and advantages will be apparent from a
reading of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a conceptual diagram of one example of a leadless
implantable medical device (LIMD) positioned in the right atrium
(RA) of a patient's heart including a leadlet positioned in the RA
of the patient's heart.
[0009] FIGS. 2A-2B depicts examples of a LIMD including a
deployable leadlet.
[0010] FIGS. 3A-3C depicts examples of a LIMD including a
deployable leadlet.
[0011] FIG. 4 is a conceptual diagram of an LIMD positioned in the
RA of a patient's heart including a leadlet extending through the
coronary sinus (CS) ostium of the patient's heart.
[0012] FIGS. 5A-5D are conceptual diagrams showing one example of
an implantable medical device (IMD) including an implantable
medical lead or leadlet extending through the right ventricular
(RV) endocardium into the ventricular septum.
[0013] FIGS. 6-7 are conceptual diagrams showing one example of an
implantable medical device (IMD) including an implantable medical
lead or leadlet extending through the RA endocardium.
[0014] FIG. 8 is a conceptual diagram showing one example of a
"screw-like" structure that may be used to support and fixate one
or more electrodes in myocardial tissue.
[0015] FIG. 9 is a block diagram of illustrative circuitry that may
be enclosed within a housing of the devices and systems of FIGS.
1-8, for example, to provide the functionality and therapy
described herein.
[0016] FIG. 10 depicts an illustrative ventricular septum lead and
delivery system with components all located with the delivery
catheter.
[0017] FIG. 11 depicts the ventricular septum lead and delivery
system of FIG. 10 with the delivery catheter partially retracted
thereby releasing the fixation tines of the outer lead body.
[0018] FIG. 12 depicts the ventricular septum lead and delivery
system of FIGS. 10-11 with the delivery catheter and the penetrator
element both completed removed.
[0019] FIG. 13 depicts the ventricular septum lead and delivery
system of FIGS. 10-11 with the inner lead body extended from the
outer lead body.
[0020] FIG. 14 depicts of an illustrative quadripolar lead.
DETAILED DESCRIPTION
[0021] The present disclosure makes reference to a leadless
implantable medical device (LIMD). Examples LIMDs having a leadlet
that may be used are described in U.S. Pat. No. 10,463,853, granted
Nov. 5, 2019, which is incorporated by reference in its
entirety.
[0022] The present disclosure also makes reference to the triangle
of Koch region. Examples of uses of the triangle of Koch region are
described U.S. Patent Application Publication No. 2019/0290905
published on Sep. 26, 2019, which is incorporated by reference in
its entirety.
[0023] In general, any suitable type of IMD (or LIMD) including a
lead or leadlet may be used. Non-limiting examples of suitable IMDs
include an implantable transvenous pacemaker, a transvenous cardiac
resynchronization therapy (CRT) device, a transvenous CRT pacemaker
(CRT-P), a transvenous CRT defibrillator (CRT-D), an implantable
transvenous cardioverter defibrillator (ICD), a subcutaneous ICD
(S-ICD), and a subcutaneous medical device.
[0024] One example of a LIMD 10 positioned in the right atrium (RA)
of a patient's heart 2 including a leadlet 20 positioned in the RA
of the patient's heart 2 is depicted in FIG. 1. The LIMD 10 may
include a housing 11 extending from a distal end region 12 to a
proximal end region 14. The leadlet 20 may be physically and
operably coupled to the proximal end region 14 of the housing 11 of
LIMD 10.
[0025] The LIMD 10 may be used to sense electrical activity of the
patient's heart or to deliver cardiac therapy to the patient's
heart. In general, a first electrode 21 operably and physically
coupled to the leadlet 20 may be implanted in the RA endocardium or
myocardium. And, a second electrode 31 may be operably and
physically coupled to a fixation element 30 extending from the
distal end region 12 of the LIMD 10 and may be implanted in the
left ventricular (LV) myocardium. More specifically, the second
electrode 31 may be coupled to a distal end region 12 of an
implantable housing 11 of the LIMD 10, such as disposed on a
fixation element 30 (e.g., helical or screw-like structure)
extending away from the housing 11 of the LIMD 10 to facilitate
fixation. The first electrode 21 may be coupled to a leadlet 20
extending from a proximal end region 14 of the housing 11 of the
LIMD 10. The LIMD 10 may be described as a ventricular LIMD
implanted in the atrium that paces the ventricle that also includes
a leadlet, or "pig tail," that paces the atrium.
[0026] The LIMD 10 may be used in any suitable manner. In some
embodiments, a method of using the LIMD 10 may include implanting
the first, or right atrial, electrode 21 on the right atrial
endocardium or in the right atrial myocardium of the patient's
heart 2. It may be described that the leadlet 20 extends from a
distal end, or first portion, to a proximal end, or second portion.
The first, or right atrial, electrode 21 may be coupled to the
distal end, or first portion, of the leadlet 20. The proximal end,
or second portion, of the leadlet 20 may be coupled to the proximal
end region 14 of the housing 11 of the LIMD 10. Processing
circuitry 19 may be disposed in the housing 11 and operably coupled
to the electrodes 21, 31.
[0027] An illustrative method may include implanting a left
ventricular electrode through or proximate to the triangle of Koch
region of the right atrium, such as in the coronary sinus (CS)
ostium, through the right atrial endocardium, and through central
fibrous body and into the basal, septal, or basal-septal region in
the left ventricular myocardium of the patient's heart. The left
ventricular electrode may be leadlessly coupled to a distal portion
of the implantable housing. The processing circuitry may be
operably coupled to the left ventricular electrode. The method may
further include monitoring electrical activity using the processing
circuitry and at least one of the right atrial electrode and the
left ventricular electrode. Further, the method may include
delivering pacing therapy using the processing circuitry and at
least one of the right atrial electrode and the left ventricular
electrode.
[0028] In another embodiment, an LIMD similar to the LIMD 10 of
FIG. 1 may be utilized in a different configuration or method. For
example, the LIMD may include a right atrial electrode for
implantation on the right atrial endocardium or in the right atrial
myocardium of the patient's heart, and the right atrial electrode
may be leadlessly coupled to a distal end region, or distal
portion, of an implantable housing of the LIMD. Further, a left
ventricular electrode may be implanted through or proximate to the
triangle of Koch region of the right atrium, such as in the CS
ostium, through the right atrial endocardium, and through central
fibrous body and into the basal, septal, or basal-septal region in
the left ventricular myocardium of the patient's heart. The left
ventricular electrode may be coupled to a distal end region, or a
first portion, of a leadlet. A proximal end region, or a second
portion, of the leadlet may be coupled to a proximal end region, or
proximal portion, of the implantable housing of the LIMD. The
processing circuitry located in the housing may be operably coupled
to both of the right and the left ventricular electrode. The LIMD
may monitor electrical activity using the processing circuitry and
at least one of the right atrial electrode and the left ventricular
electrode. Further, the LIMD may deliver pacing therapy using the
processing circuitry and at least one of the right atrial electrode
and the left ventricular electrode.
[0029] An illustrative LIMD 40 including a deployable leadlet is
depicted in FIGS. 2A-2B. The LIMD 40 may include one or more
fixation elements (although not shown), a deployable leadlet 45, a
first electrode 50, and a second electrode 52 coupled to the
leadlet 45. The leadlet 45 extends from a proximal end region 54 to
a distal end region 56, and the second electrode is located
proximate (or within) the distal end region 56.
[0030] The LIMD 40 may include a body portion 41 and a sheath
portion 42 moveable with respect to the body portion 41. The sheath
portion 42 may define an opening or aperture within which the body
portion 41 is located. The LIMD 40 may define a stowed
configuration or position as shown in FIG. 2A and a deployed
configuration as shown in FIG. 2B. When in the stowed
configuration, the body portion 41 may be located substantially
completely within the opening of the sheath portion 42 such that,
e.g., the deployable leadlet 45 is also in a stowed configuration
where the leadlet 45 does not extend beyond or outside of the
sheath portion 42. More specifically, when in the stowed
configuration, the leadlet 45 may reside within a recess, or
groove, 49. The leadlet 45 may include (e.g., be formed of)
resilient materials such that, e.g., when the sheath portion 42 is
retracted 48 away exposed a distal end region 44 of the body
portion 41, the leadlet 45 may move 47 away from (e.g., pivot or
partially rotate away from) the body portion 41 in at least
partially radial manner to position the distal end region 56, and
consequently, the second electrode 52, of the leadlet 45, away from
the body portion 41.
[0031] Although not shown in FIGS. 2A-2B, one or more fixation
elements may be disposed on the distal end region 44 of the body
portion 41 of the LIMD 40 and extend distally from the body portion
41. The one or more fixation elements may be electrically active or
passive. The first electrode 50 may be positioned on the distal end
region 44 of the body portion 41 of the LIMD 40 to engage the
endocardial wall of the patient's heart. The second electrode 52
may be coupled to the leadlet 45 extending at least partially in a
radial direction away from the body portion 41 in a deployed
position. As described herein, the body portion 41 may define, or
include, a recess 49 to at least partially receive the leadlet 45
in the stowed position. In other words, it may be described that
the body portion 41 may be delivered in a "cup" (e.g., defined by
the sheath portion 42) and protracted to deploy the body portion 41
for implantation. In some embodiments, the endocardial wall is the
right atrial endocardial wall. Additionally, as can be seen in FIG.
2B, the leadlet 45 may described as defining a shape have two
sections or portions. The first section, which is closest to the
proximal end region 54, may extend tangentially and in a straight
line away from the outside (e.g., circumference) of the body
portion 41. The second section, which is closer to the distal end
region 56, may then curve or bend away from the tangentially
straight line defined by the first section back towards a path
somewhat or partially parallel to the outside (e.g., circumference)
of the body portion 41.
[0032] An illustrative LIMD 60 including a deployable leadlet 65 is
depicted in FIGS. 3A-3B. The LIMD 60 may include one or more
fixation elements 69 (e.g., curved tines), a deployable leadlet 65,
a first electrode 70, and a second electrode 72 coupled to the
leadlet 65. The leadlet 65 extends from a proximal end region 74 to
a distal end region 76, and the second electrode 72 is located
proximate (or within) the distal end region 76.
[0033] The LIMD 60 may include a body portion 61 and a sheath
portion 62 moveable with respect to the body portion 61. The sheath
portion 62 may define an opening or aperture within which the body
portion 61 is located. The LIMD 60 may define a stowed
configuration or position when the body portion 61 is substantially
completely within the opening of the sheath portion 62 such that,
e.g., the deployable leadlet 65 is also in a stowed configuration
or position where the leadlet 65 does not extend beyond or outside
of the sheath portion 62. The LIMD 60 may further define a deployed
configuration as shown in FIGS. 3A-3B. More specifically, when in
the stowed configuration, the leadlet 65 may reside within a recess
or groove. The leadlet 65 may include (e.g., be formed of)
resilient materials such that, e.g., when the sheath portion 62 is
retracted 68 away exposed a distal end region 64 of the body
portion 61, the leadlet 65 may move 67 (e.g., pivot or partially
rotate) away from the body portion 61 in at least partially radial
manner to position the distal end region 76, and consequently, the
second electrode 72, of the leadlet 65, away from the body portion
61.
[0034] One or more fixation elements 69 may be disposed on the
distal end region 64 of the body portion 61 of the LIMD 60 and
extend distally from the body portion 61. The one or more fixation
elements 69 may be electrically active or passive. The first
electrode 70 may be positioned on the distal end region 64 of the
body portion 61 of the LIMD 40 to engage the endocardial wall of
the patient's heart. The second electrode 72 may be coupled to the
leadlet 65 extending at least partially in a radial direction away
from the body portion 61 in a deployed position as shown. As
described herein, the body portion 61 may define, or include, a
recess to at least partially receive the leadlet 65 in the stowed
position. In other words, it may be described that the body portion
61 may be delivered in a "cup" (e.g., defined by the sheath portion
62) and protracted to deploy the body portion 61 for implantation.
In some embodiments, the endocardial wall is the right atrial
endocardial wall.
[0035] Another illustrative LIMD 63 including a deployable leadlet
65 is depicted in FIG. 3C. The LIMD 63 may be substantially similar
to the LIMD 60 except for the movement of the leadlet 65. As shown,
the leadlet 65 of LIMD 63 swings, or rotates, away from the body
portion 61 in an opposite direction than the leadlet 65 of LIMD 60
to, e.g., provide ease of re-sheathing the body portion 61 into the
sheath portion 62. More specifically, the sheath portion 62 may
contact and "fold down" the leadlet 65 when the body portion 61 is
moved with respect to the sheath portion 62 of the LIMD 63 to
position the body portion 61 within the aperture or opening of the
sheath portion 62 (i.e., the body portion 61 being retracted into
the sheath portion 62). In other words, the LIMD 63 may be provide
"easy" retraction of the body portion 61 within the sheath portion
62.
[0036] The LIMDs 40, 60, 63 may be used in any suitable manner. In
some embodiments, a method of using the LIMDs 40, 60, 63 may
include attaching one or more fixation elements 69 thereof to the
endocardial wall of the patient's heart. The fixation elements 69
may be coupled to the distal end region, or distal portion, 44, 64
of the body portion 41, 61. Processing circuitry 19 may be disposed
in the body portion 41, 61. The method of using the LIMDs 40, 60,
63 may also include implanting the first electrode 50, 70 to engage
the endocardial wall of the patient's heart when the fixation
element is attached. The first electrode 50, 70 may be leadlessly
coupled to the distal end region, or distal portion, 44, 64 of the
body portion 41, 61. The processing circuitry 19 may be operably
coupled to each of the first and second electrodes 50, 52, 70,
72.
[0037] The method of using the LIMDs 40, 60, 63 may further include
implanting the second electrode 52, 72 to engage the endocardial
wall of the patient's heart when the LIMD 40, 60, 63 is in the
deployed configuration placing the leadlet 45, 65 in the deployed
position. More specifically, it may be described that the second
electrode 52, 72 is coupled to the distal end region, or a first
portion, 56, 76 of the leadlet 45, 65 and the proximal end region,
or a second portion, 54, 74 of the leadlet 45, 65 may be coupled to
the distal end region 44, 64 of the body portion 41, 61. As
described herein, the leadlet 45, 65 may extend at least partially
in a radial direction away from the body portion 41, 61 in the
deployed configuration/position so as to, e.g., engage cardiac
tissue with the second electrode 52, 72.
[0038] The method of using the LIMDs 40, 60, 63 may further include
monitoring electrical activity using the processing circuitry 19
and at least one of the first electrode 50, 70 and the second
electrode 52, 72. Further, the method of using the LIMDs 40, 60, 63
may further include delivering pacing therapy using the processing
circuitry 19 and at least one of the first electrode 50, 70 and the
second electrode 52, 72.
[0039] Although no fixation element is depicted on the LIMD 40 in
FIGS. 2A-2B and tines 69 are depicted on the LIMD 60 of FIGS.
3A-3C, it is to be understood that any suitable fixation element
may be used. In some embodiments, the fixation elements may include
one or more helix structures or screw-like structures. In some
embodiments, the fixation elements may include one or more
adhesives (which may be used in conjunction with other fixation
elements such as a helix structure).
[0040] A conceptual diagram of an LIMD 80 positioned in the right
atrium of a patient's heart including a leadlet 85 extending
through the coronary sinus (CS) ostium of the patient's heart is
depicted in FIG. 4. The LIMD 80 may include an implantable housing
81 extending from a proximal end region 82 to a distal end region
84. The LIMD 80 may include a plurality of electrodes. The
plurality of electrodes may include one or more right atrial
electrodes configured to sense and/or pace right atrial tissue and
one or more left ventricular electrodes configured to sense and/or
pace left ventricular tissue. For example, as shown, the LIMD 80
includes a right atrial electrode 90 positioned on the proximal end
region 82 of the implantable housing 81 of the LIMD 80. The right
atrial electrode 90 may be implanted in the right atrial
endocardium or in the right atrial myocardium of the patient's
heart. In some embodiments, the right atrial electrode 90 may be
positioned proximate to (e.g., in contact with, adjacent, partially
within, within, etc.) the right atrial appendage.
[0041] The LIMD 80 in FIG. 4 also includes a pair of left
ventricular electrodes 92 coupled to the leadlet 85 extending
distally from the housing 81. The leadlet 85 may be described as
extending from a proximal region 86 to a distal region 87. The
proximal region 86 is coupled to the distal end region 84 of the
housing 81. The electrodes 92 are positioned on or proximate the
distal region 87 of the leadlet 85. When implanted, the leadlet 85
may extend through the coronary sinus ostium and into the coronary
sinus or a coronary vein of the patient's heart to position the
left ventricular electrodes 92 proximate the left ventricle of the
patient's heart. Thus, in some embodiments, the left ventricular
electrodes 92 may be implanted in the coronary sinus or a coronary
vein, and in other embodiments, the left ventricular electrodes may
be implanted in the left ventricular myocardium of the patient's
heart, for example, using a helical structure or screw-like
structure. In the embodiment depicted in FIG. 4, it may be
described that a plurality of left ventricular electrodes 92 are
coupled to the leadlet 85, for example, including an anode and a
cathode. In some embodiments, the plurality of left ventricular
electrodes 92 may be used for field steering, for example, to avoid
capture of the left atrium (LA) of the patient's heart.
[0042] The LIMD 80 may be described as being implanted in the
atrium to sense or pace the atrium. The leadlet 85, which may be
advanced a relatively long way down the coronary sinus, anterior
interventricular vein (AIV) or great cardiac vein (GCV), or lateral
vein, to pace the left ventricle or may be advanced a short way
into the coronary sinus and then fixated "down" into left
ventricular myocardium to pace the left ventricle. In some
embodiments, the leadlets described herein may be quadripolar
leadlets including four electrodes. Further, any of the leadlets
described herein may also use active fixation, which may allow for
adjustment of electrode depth, for example, into the left
ventricular myocardium.
[0043] The LIMD 80 of FIG. 4 may be used in any suitable manner. In
some embodiments, a method of using the LIMD 80 may include
implanting the right atrial electrode 90 on the right atrial
endocardium or in the right atrial myocardium of the patient's
heart. The right atrial electrode 90 may be leadlessly coupled to a
proximal end region, or portion, 82 of the implantable housing 81.
Processing circuitry 19 may be disposed in the housing 81 and may
be operably coupled to the right atrial electrode 90.
[0044] The method of using the LIMD 80 may also include implanting
the left ventricular electrodes 92 through the coronary sinus
ostium and into the coronary sinus or a coronary vein of the
patient's heart. The left ventricular electrodes 92 may be coupled
to the distal region, or first portion, 87 of the leadlet 85. The
proximal region, or second portion, 86 of the leadlet 85 may be
coupled to the distal end region 84 of the implantable housing 81.
The processing circuitry 19 may also be operably coupled to the
left ventricular electrodes 92.
[0045] The method of using the LIMD 80 may further include
monitoring electrical activity using the processing circuitry 19
and at least one of the right atrial electrode 90 and the left
ventricular electrodes 92 and may include delivering pacing therapy
using the processing circuitry 19 and at least one of the right
atrial electrode 90 and the left ventricular electrodes 92. In some
embodiments, implanting the left ventricular electrodes 92 may
include implanting the left ventricular electrodes 92 into the left
ventricular myocardium from the coronary sinus proximal to the
posterior vein of the patient's heart. In some embodiments,
implanting the left ventricular electrodes 92 may include
implanting the left ventricular electrodes 92 into the anterior
interventricular vein (AIV) of the patient's heart. In some
embodiments, implanting the left ventricular electrodes 92 may
include implanting the left ventricular electrodes 92 into the
lateral vein of the patient's heart. Further, in some embodiments,
delivering pacing therapy may include utilizing field steering to
avoid left atrial capture by the left ventricular electrodes
92.
[0046] Conceptual diagrams showing one example of implantation of
an implantable medical device (IMD) 100 including an implantable
medical lead or leadlet 150 extending through the right ventricular
(RV) endocardium are depicted in FIGS. 5A-5D. Although a lead is
described herein, a leadlet extending from an intracardiac
implantable housing of an LIMD may also be used. In other words,
the lead 150 could be either a lead extending from an IMD located,
or positioned, outside of the heart or a leadlet extending from a
LIMD located, or positioned, inside of the heart.
[0047] The lead 150 may extend from a proximal portion coupled to
the a control portion of the IMD 100 (e.g., a housing, battery,
controller, processing circuitry, etc.) to a distal portion 154
that is positioned in or proximate the left ventricular myocardium
extending along the left ventricular endocardial wall 8, for
example, toward the apex of the patient's heart. The distal portion
154 may be proximate to the left bundle branch (LBB) of the
patient's heart. Although any suitable delivery system may be used
to deliver the lead 150, a delivery system and method of
implantation using such delivery system are shown and described
with respect to FIGS. 5A-5D. Generally, the delivery system may be
described as puncturing the right ventricular endocardium 6 to
allow a lead 150 to be simply pushed into the septal myocardium 7,
or interventricular septal wall, and tunneled up or down the
septum. The lead 150 may be tunneled into the basal-septal,
mid-septal, or even apical septal region with the septal myocardium
7.
[0048] The lead 150 may be a multipolar lead such as, e.g., the
quadripolar lead 590 described herein with respect to FIG. 14. More
specifically, a distal portion 154 of the lead 150 may have a
quadripolar configuration, which may be the same or similar to an
ATTAIN STABILITY.TM. or ATTAIN STABILITY QUAD.TM. or ATTAIN
PERFORMA.TM. leads available from Medtronic plc of Dublin, Ireland.
A side helix or hook usable for fixation that may be disposed on
the distal portion, which may be selectively electrically active or
passive and may be mechanically active or adjustable. Another
exemplary lead that may be employed is described in U.S. Pat. No.
9,901,732 to Sommer et al., granted Feb. 27, 2018, which is
incorporated by reference in its entirety, in which electrodes are
jumpered in a diagonal configuration in order to increase the
opportunity to capture cardiac tissue.
[0049] A guide element 130, such as a guidewire, a steerable stylet
or wire, or a hybrid of stylet guidewire that is a part of the
ATTAIN family, may be used to guide 130 the lead 150 into the
septum 7. With multiple electrodes and different spacing, one lead
150 may be used to pace the atrium and multiple locations down the
septum 7. One example of a guiding element that may be used is
described in U.S. Pat. No. 7,881,806 to Sommer et al., granted Feb.
1, 2011, which is incorporated by reference in its entirety.
[0050] The IMD 100 including the lead 150 may be used in any
suitable manner. In some embodiments, a method of delivering and
using the IMD 100 may include delivering a delivery catheter 110
and a penetration element 120 disposed in the delivery catheter 110
to the right ventricular endocardium 6 of the interventricular
septal wall of a patient's heart as shown in FIG. 5A. The delivery
catheter 110 may be configured to provide positioning of the distal
end 115 of the delivery catheter to target implantation location
101 such that the distal end 115 is positioned adjacent to (e.g.,
substantially flush or in contact with) the right ventricular
endocardium 6. For example, in one embodiment, the delivery
catheter 110 extends from a proximal portion to a distal portion
114, and the distal portion 114 defines a curvature to position the
distal end 115 of the catheter 110 substantially flush to the right
ventricular endocardium 6.
[0051] The method may include puncturing the right ventricular
endocardium 6 using the penetration element 120 to form an opening
through the right ventricular endocardium 6 and into the
interventricular septal wall 7 as shown in FIG. 5B. The penetration
element 120 may then be retracted through the delivery catheter
110. Then, a distal portion of a guide element 130 may be advanced
through the delivery catheter 110 and the opening and into the
interventricular septal wall 7 to extend along the left ventricular
endocardial wall 8. The guide element 130 may extend from a
proximal region to a distal region 134 and the distal region 134
may be configured to be positioned into the interventricular septal
wall 7 to extend along the left ventricular endocardial wall 8. In
at least one embodiment, the distal region 134 may define or
include a distal curvature portion that curves when exiting the
delivery catheter 110 into the interventricular septal wall 7 so as
to deliver at least a region of a distal portion 154 of an
implantable medical lead 150 substantially parallel to the
interventricular septal wall 7 in the left ventricular
myocardium.
[0052] In addition, a distal portion of the implantable medical
lead 150 of the device 100 may be advanced or delivered over the
guide element 130 to the left ventricular myocardium to extend
along the left ventricular endocardial wall 8 to position one or
more left ventricular electrodes 162 on the distal portion in the
left ventricular myocardium. In one or more embodiments, the guide
element 130 does not extend beyond the tip of the lead 150, and
instead, may remain a selected distance away from the tip (e.g.,
about 1 centimeter) to allow tip to flex during blunt
dissection/tunneling of the lead 150. Further, Examples of the
guide element 130 may include a steerable stylet, shaped stylets,
etc. In some embodiments, one or more left ventricular electrodes
162 may be positioned proximate to the left bundle branch (LBB) of
the conduction system of the patient's heart.
[0053] In some embodiments, a right ventricular electrode 160 on
the lead 150 may be positioned/implanted proximate to the right
ventricular endocardium 6. The right ventricular electrode 160 may
be positioned proximal to the left ventricular electrode on the
distal portion 154 of the implantable medical lead 150.
[0054] Further, the method of using IMD 100 may include monitoring
electrical activity of at least one of the right ventricular
electrode 160 and one or more of the left ventricular electrodes
162, and delivering pacing therapy using at least one of the right
ventricular electrode 160 and the left ventricular electrodes 162.
In some embodiments, delivering pacing therapy may include
delivering pacing pulses to the left ventricular electrodes 162
configured to pace the left bundle branch of the conduction system
of the patient's heart. In some embodiments, the implantable
medical lead 150 may include a plurality of left ventricular
electrodes, a plurality of right ventricular electrodes, or
both.
[0055] FIGS. 6-7 are conceptual diagrams showing one example of an
implantable medical device (IMD) 200 including an implantable
medical lead or leadlet 250 extending through the right atrial
endocardium. Although a lead 250 is described herein, a leadlet
extending from an intracardiac implantable housing may also be
used. A distal portion 254 of the lead 250 may be positioned in the
left ventricular myocardium extending along the left ventricular
endocardial wall, for example, toward the apex of the patient's
heart. The distal portion 254 may be proximate to the left bundle
branch (LBB) of the patient's heart 2. Any suitable delivery system
and method may be used to deliver the lead 250. In at least one
embodiment, the delivery systems described herein with respect to
FIG. 5 and FIGS. 10-14 may be utilized. For example, a delivery
system may be configured to puncture the right atrial endocardium
and central fibrous body (CFB) to allow the lead 250 to be simply
pushed into the septal myocardium, or interventricular septal wall,
and tunneled up or down the septum as shown by the trajectory 270
in FIG. 7. The lead 250 may be tunneled into the basal-septal,
mid-septal, or even apical septal region.
[0056] A multipolar lead may be used such as, e.g., the quadripolar
lead 590 described herein with respect to FIG. 14. The distal
portion 254 of the lead 250 may have a quadripolar configuration,
which may be the same or similar to an ATTAIN STABILITY.TM. or
ATTAIN STABILITY QUAD.TM. or ATTAIN PERFORMA.TM. leads available
from Medtronic plc of Dublin, Ireland. A side helix or hook usable
for fixation that may be disposed on the distal portion, which may
be selectively electrically active or passive and may be
mechanically active or adjustable. Another exemplary lead that may
be employed is described in U.S. Pat. No. 9,901,732 to Sommer et
al., granted Feb. 27, 2018, which is incorporated by reference in
its entirety, in which electrodes are jumpered in a diagonal
configuration in order to increase the opportunity to capture
cardiac tissue.
[0057] The guiding element may be a guidewire, a steerable stylet
or wire, or a hybrid of stylet guidewire that is a part of the
ATTAIN family, may be used to guide the lead into the septum. With
multiple electrodes and different spacing, one lead may be used to
pace the atrium and multiple locations down the septum. One example
of a guiding element that may be used is described in U.S. Pat. No.
7,881,806 to Sommer et al., granted Feb. 1, 2011, which is
incorporated by reference in its entirety.
[0058] The IMD 200 may be used in any suitable manner. In some
embodiments, a method of implanting and using the IMD 200 may
include delivering the delivery catheter and a penetration element
disposed in the delivery catheter to the right atrial endocardium
in or proximate to the triangle of Koch region of a patient's
heart, such as in the coronary sinus ostium. The method of
implanting and using the IMD 200 may also include puncturing the
right atrial endocardium and the central fibrous body using the
penetration element to form an opening through the right
ventricular endocardium and the central fibrous body and into the
interventricular septal wall. Then, the penetration element may be
retracted. Then, a distal portion of a guide element may be
advanced through the delivery catheter and the opening and into the
interventricular septal wall to extend along the left ventricular
endocardial wall.
[0059] In addition, the method of implanting and using the IMD 200
may include delivering a distal portion 254 of an implantable
medical lead 250 over the guide element to the left ventricular
myocardium to extend along the left ventricular endocardial wall to
position one or more left ventricular electrodes 262 on the distal
portion 254 in the left ventricular myocardium. In some
embodiments, the left ventricular electrodes 262 may be positioned
proximate to the left bundle branch of the conduction system of the
patient's heart. In some embodiments, the method of implanting and
using the IMD 200 may also include implanting one or more right
atrial electrodes 260 proximate to the right atrial endocardium.
The right atrial electrodes 260 may be positioned proximally along
the lead 250 to the left ventricular electrodes 262 on the distal
portion 254 of the implantable medical lead 250.
[0060] In some embodiments, the method of using the IMD 100 may
further include monitoring electrical activity of at least one of
the right atrial electrodes 260 and the left ventricular electrodes
262, and delivering pacing therapy using at least one of the right
atrial electrodes 260 and the left ventricular electrodes 262. In
some embodiments, delivering pacing therapy may include delivering
pacing pulses to the left ventricular electrodes 262 configured to
pace the left bundle branch of the conduction system of the
patient's heart. Further, In some embodiments, the implantable
medical lead may include a plurality of left ventricular
electrodes, a plurality of right atrial electrodes, or both.
[0061] A conceptual diagram showing one example of a "screw-like"
structure that may be used to support and fixate one or more
electrodes in myocardial tissue is depicted in FIG. 8. In some
embodiments, IMD or LIMD may include an elongate member 300
extending between a proximal portion and a distal portion 304. A
first electrode 320 may be disposed on the distal portion 304 of
the elongate member. A second electrode 322 may be disposed
proximal to the first electrode 320 on the distal portion 304 of
the elongate member 300. A first threaded bulb region 312 may be
disposed between the first and second electrodes 320, 322 on the
distal portion 304 of the elongate member 300. A second threaded
bulb region 314 disposed between the first threaded bulb region 312
and the second electrode 322 on the distal portion 304 of the
elongate member 300. In some embodiments, the threaded bulb regions
312, 314 may share a similar threaded pattern or spacing.
[0062] FIG. 9 is a block diagram of circuitry that may be enclosed
within the housings of an illustrative IMD 400 to provide the
functions of cardiac therapy described herein with respect to FIGS.
1-8. In other words, the IMD 400 may be used with any one or more
of the embodiments described with respect to FIGS. 1-8. The
electronic circuitry of the device 400 may include software,
firmware, and hardware that cooperatively monitor atrial and
ventricular electrical cardiac signals, determine when a cardiac
therapy is necessary, and/or deliver electrical pulses to the
patient's heart according to programmed therapy mode and pulse
control parameters. The electronic circuitry may include a control
circuit 480 (e.g., including processing circuitry), a memory 482, a
therapy delivery circuit 484, a sensing circuit 486, and/or a
telemetry circuit 488. In some examples, the device 400 includes
one or more sensors 490 for producing a signal that is correlated
to a physiological function, state, or condition of the patient,
such as a patient activity sensor, for use in determining a need
for pacing therapy and/or controlling a pacing rate.
[0063] The power source 498 may provide power to the circuitry of
the device 400 including each of the components 480, 482, 484, 486,
488, and 490, as needed. The power source 498 may include one or
more energy storage devices, such as one or more rechargeable or
non-rechargeable batteries. The connections between the power
source 498 and each of the components 480, 482, 484, 486, 488, and
490 are to be understood from the general block diagram illustrated
but are not shown for the sake of clarity. For example, the power
source 498 may be coupled to one or more charging circuits included
in the therapy delivery circuit 484 for providing the power needed
to charge holding capacitors included in the therapy delivery
circuit 484 that are discharged at appropriate times under the
control of the control circuit 480 for delivering pacing pulses,
e.g., according to a dual chamber pacing mode such as DDI(R). The
power source 498 may also be coupled to components of the sensing
circuit 486, such as sense amplifiers, analog-to-digital
converters, switching circuitry, etc., sensors 490, the telemetry
circuit 488, and the memory 482 to provide power to the various
circuits.
[0064] Any suitable technique may be used to recharge a
rechargeable power source 498. In some embodiments, the device 400
may include an antenna, inductive coils, or other inductive
coupling structures configured to couple to another device, such as
an external charger or programmer, to receive power in situ.
Various examples of charging a leadless implantable medical device
are described in U.S. Patent Pub. No. 2018/0212451 (Schmidt et
al.), filed Jan. 26, 2017, entitled "Recharge of Implanted Medical
Devices," which is incorporated herein by reference in its
entirety. The device 400 may also be configured to use various
techniques to extend the life of the power source 498, such as a
low-power mode.
[0065] Various examples of power sources and techniques related to
power sources may be used, such as those found in, for example,
U.S. Pat. No. 8,383,269 (Scott et al.), granted Feb. 26, 2013, U.S.
Pat. No. 8,105,714 (Schmidt et al.), granted Jan. 31, 2012, and
U.S. Pat. No. 7,635,541 (Scott et al.), granted Dec. 22, 2009, each
of which is incorporated herein by reference in its entirety.
[0066] The functional blocks shown represent functionality included
in the device 400 and may include any discrete and/or integrated
electronic circuit components that implement analog, and/or digital
circuits capable of producing the functions attributed to the
device 400 herein. The various components may include processing
circuitry, such as an application specific integrated circuit
(ASIC), an electronic circuit, a processor (shared, dedicated, or
group), and memory that execute one or more software or firmware
programs, a combinational logic circuit, state machine, or other
suitable components or combinations of components that provide the
described functionality. The particular form of software, hardware,
and/or firmware employed to implement the functionality disclosed
herein will be determined primarily by the particular system
architecture employed in the medical device and by the particular
detection and therapy delivery methodologies employed by the
medical device. Providing software, hardware, and/or firmware to
accomplish the described functionality in the context of any modern
cardiac medical device system, given the disclosure herein, is
within the abilities of one of skill in the art.
[0067] The memory 482 may include any volatile, non-volatile,
magnetic, or electrical non-transitory computer readable storage
media, such as random-access memory (RAM), read-only memory (ROM),
non-volatile RAM (NVRAM), electrically-erasable programmable ROM
(EEPROM), flash memory, or any other memory device. Furthermore,
the memory 482 may include a non-transitory computer readable media
storing instructions that, when executed by one or more processing
circuits, cause the control circuit 480 and/or other processing
circuitry to perform a single, dual, or triple chamber pacing
(e.g., single or multiple chamber pacing) function or other sensing
and therapy delivery functions attributed to the device 400. The
non-transitory computer-readable media storing the instructions may
include any of the media listed above.
[0068] The control circuit 480 may communicate, e.g., via a data
bus, with the therapy delivery circuit 484 and the sensing circuit
486 for sensing cardiac electrical signals and controlling delivery
of cardiac electrical stimulation therapies in response to sensed
cardiac events, e.g., P-waves and R-waves, or the absence thereof.
The electrodes 422, 424, 442 (e.g., left ventricular electrodes,
right ventricular electrodes, right atrial electrodes, housing
electrodes, etc.) may be electrically coupled to the therapy
delivery circuit 484 for delivering electrical stimulation pulses
to the patient's heart and to the sensing circuit 486 and for
sensing cardiac electrical signals.
[0069] The sensing circuit 486 may include an atrial (A) sensing
channel 487 and a ventricular (V) sensing channel 489. For example,
the electrodes 422, 424 may be coupled to the atrial sensing
channel 487 for sensing atrial signals, e.g., P-waves attendant to
the depolarization of the atrial myocardium. Further, in some
examples, the sensing circuit 486 may include switching circuitry
for selectively coupling one or more of the available electrodes to
cardiac event detection circuitry included in the atrial sensing
channel 487. Switching circuitry may include a switch array, switch
matrix, multiplexer, or any other type of switching device suitable
to selectively couple components of the sensing circuit 486 to
selected electrodes. Further, for example, electrodes 424, 442 may
be coupled to the ventricular sensing channel 489 for sensing
ventricular signals, e.g., R-waves attendant to the depolarization
of the ventricular myocardium.
[0070] Each of the atrial sensing channel 487 and the ventricular
sensing channel 489 may include cardiac event detection circuitry
for detecting P-waves and R-waves, respectively, from the cardiac
electrical signals received by the respective sensing channels. The
cardiac event detection circuitry included in each of the channels
487 and 489 may be configured to amplify, filter, digitize, and
rectify the cardiac electrical signal received from the selected
electrodes to improve the signal quality for detecting cardiac
electrical events. The cardiac event detection circuitry within
each channel 487 and 489 may include one or more sense amplifiers,
filters, rectifiers, threshold detectors, comparators,
analog-to-digital converters (ADCs), timers, or other analog or
digital components. A cardiac event sensing threshold, e.g., a
P-wave sensing threshold and an R-wave sensing threshold, may be
automatically adjusted by each respective sensing channel 487 and
489 under the control of the control circuit 480, e.g., based on
timing intervals and sensing threshold values determined by the
control circuit 480, stored in the memory 482, and/or controlled by
hardware, firmware, and/or software of the control circuit 480
and/or the sensing circuit 486.
[0071] Upon detecting a cardiac electrical event based on a sensing
threshold crossing, the sensing circuit 486 may produce a sensed
event signal that is passed to the control circuit 480. For
example, the atrial sensing channel 487 may produce a P-wave sensed
event signal in response to a P-wave sensing threshold crossing.
The ventricular sensing channel 489 may produce an R-wave sensed
event signal in response to an R-wave sensing threshold crossing.
The sensed event signals may be used by the control circuit 480 for
setting pacing escape interval timers that control the basic time
intervals used for scheduling cardiac pacing pulses. A sensed event
signal may trigger or inhibit a pacing pulse depending on the
particular programmed pacing mode. For example, a P-wave sensed
event signal received from the atrial sensing channel 487 may cause
the control circuit 480 to inhibit a scheduled atrial pacing pulse
and schedule a ventricular pacing pulse at a programmed
atrioventricular (AV) pacing interval. If an R-wave is sensed
before the AV pacing interval expires, the ventricular pacing pulse
may be inhibited. If the AV pacing interval expires before the
control circuit 480 receives an R-wave sensed event signal from the
ventricular sensing channel 489, the control circuit 480 may use
the therapy delivery circuit 484 to deliver the scheduled
ventricular pacing pulse synchronized to the sensed P-wave.
[0072] In some examples, the device 400 may be configured to
deliver a variety of pacing therapies including bradycardia pacing,
cardiac resynchronization therapy, post-shock pacing, and/or
tachycardia-related therapy, such as ATP, among others. For
example, the device 40 may be configured to detect non-sinus
tachycardia and deliver ATP. The control circuit 480 may determine
cardiac event time intervals, e.g., P-P intervals between
consecutive P-wave sensed event signals received from the atrial
sensing channel 487, RR intervals between consecutive R-wave sensed
event signals received from the ventricular sensing channel 489,
and P-R and/or R-P intervals received between P-wave sensed event
signals and R-wave sensed event signals. These intervals may be
compared to tachycardia detection intervals for detecting non-sinus
tachycardia. Tachycardia may be detected in a given heart chamber
based on a threshold number of tachycardia detection intervals
being detected.
[0073] The therapy delivery circuit 484 may include atrial pacing
circuit 483 and ventricular pacing circuit 485. Each pacing circuit
483 and 485 may include charging circuitry, one or more charge
storage devices such as one or more low voltage holding capacitors,
an output capacitor, and/or switching circuitry that controls when
the holding capacitor(s) are charged and discharged across the
output capacitor to deliver a pacing pulse to the pacing electrode
vector coupled to respective pacing circuits 483 or 485. The
electrodes 424, 442 may be coupled to the ventricular pacing
circuit 485 as a bipolar cathode and anode pair for delivering
ventricular pacing pulses, e.g., upon expiration of an AV or VV
pacing interval set by the control circuit 480 for providing
atrial-synchronized ventricular pacing and a basic lower
ventricular pacing rate.
[0074] The atrial pacing circuit 483 may be coupled to, for
example, the electrodes 422, 424 to deliver atrial pacing pulses.
The control circuit 480 may set atrial pacing intervals according
to a programmed lower pacing rate or a temporary lower rate set
according to a rate-responsive sensor indicated pacing rate. Atrial
pacing circuit may be controlled to deliver an atrial pacing pulse
if the atrial pacing interval expires before a P-wave sensed event
signal is received from the atrial sensing channel 487. The control
circuit 480 starts an AV pacing interval in response to a delivered
atrial pacing pulse to provide synchronized multiple chamber pacing
(e.g., dual or triple chamber pacing).
[0075] Charging of a holding capacitor of the atrial or ventricular
pacing circuit 483 or 485 to a programmed pacing voltage amplitude
and discharging of the capacitor for a programmed pacing pulse
width may be performed by the therapy delivery circuit 484
according to control signals received from the control circuit 480.
For example, a pace timing circuit included in the control circuit
480 may include programmable digital counters set by a
microprocessor of the control circuit 480 for controlling the basic
pacing time intervals associated with various single chamber or
multiple chamber pacing (e.g., dual or triple chamber pacing) modes
or anti-tachycardia pacing sequences. The microprocessor of the
control circuit 480 may also set the amplitude, pulse width,
polarity, or other characteristics of the cardiac pacing pulses,
which may be based on programmed values stored in the memory
482.
[0076] The device 400 may include other sensors 490 for sensing
signals from the patient for use in determining a need for and/or
controlling electrical stimulation therapies delivered by the
therapy delivery circuit 484. In some examples, a sensor indicative
of a need for increased cardiac output may include a patient
activity sensor, such as an accelerometer. An increase in the
metabolic demand of the patient due to increased activity as
indicated by the patient activity sensor may be determined by the
control circuit 480 for use in determining a sensor-indicated
pacing rate.
[0077] Control parameters utilized by the control circuit 480 for
sensing cardiac events and controlling pacing therapy delivery may
be programmed into the memory 482 via the telemetry circuit 488,
which may also be described as a communication interface. The
telemetry circuit 488 includes a transceiver and antenna for
communicating with an external device such as a programmer or home
monitor, using radio frequency communication or other communication
protocols. The control circuit 480 may use the telemetry circuit
488 to receive downlink telemetry from and send uplink telemetry to
the external device. In some cases, the telemetry circuit 488 may
be used to transmit and receive communication signals to/from
another medical device implanted in the patient.
[0078] An illustrative ventricular septum lead and delivery system
500 is depicted in FIGS. 10-14 that may be used in a similar manner
as the illustrative method and system described herein with respect
to FIG. 4 The lead and delivery system 500 may include a delivery
catheter 510 that extends from a proximal end region (not depicted)
to a distal end region 514. The delivery catheter 510 may define an
opening, or aperture, extending from a proximal end to a distal end
516. The other components of the lead and delivery system 500 may
be located, or positioned, within the opening of the delivery
catheter 510 for delivery to a target location such as right
ventricular endocardium, the ventricular septum, etc.
[0079] The delivery catheter 510 may be manipulable by a clinician
to locate, or position, the distal end 516 proximate (e.g.,
adjacent, in close contact with, substantially flush to, etc.) a
target location such as, e.g., the right ventricular endocardium of
the interventricular septal wall of a patient's heart, the right
atrial endocardium and central fibrous body (CFB), etc. When the
delivery catheter 510 is positioned proximate the target location,
the delivery catheter 510 may be retracted thereby exposing an
penetration element 520 located within an inner lead body 560,
which is located in an outer lead body 550, as shown in FIG. 11. In
other words, the delivery catheter 510 may be moved relative to the
remaining components of the system 500. In at least one embodiment,
the remaining components of the system 500 may be held, or kept,
secure and stationary while the delivery catheter 510 is pulled
proximally away from the target location.
[0080] The outer lead body 550 extends from a proximal end region
to a distal end region 554 and includes, among other things,
fixation elements 555 located proximate the distal end region 554.
The fixation elements 555 may be resilient such that, e.g., they
may be "folded up" within the delivery catheter 510 and may move,
or "spring," to a deployed state as shown in FIG. 11. In other
words, the fixation elements 555 may be configured in a stowed
configuration and a deployed configuration. The fixation elements
555 may be predisposed in the deployed configuration and configured
to move back to the deployed configuration without application of
an outside force. Thus, the delivery catheter 510 may provide an
outside force by contacting the fixation elements 555 to hold
(e.g., "fold down," restrict, etc.) the fixation elements 555 in
the stowed configuration when the distal end region 554 is located
within the opening of the delivery catheter 510. More specifically,
each of the fixation elements extends from a proximal end 556
attached to the distal end region 554 to a distal end 558, and when
the stowed configuration, the distal end 558 may extend and point
to the distal end 516 of the delivery catheter 510. When the distal
end 516 of the delivery catheter 510 is adjacent tissue at a target
location and the delivery catheter 510 is moved to release the
fixation elements 555 of the outer lead body 550, the fixation
elements 555 may pierce the tissue at the target location and
"pull" the outer lead body 550 (and inner lead body 560 and
penetration element 520) into the tissue. Such fixation element
configuration is described further in U.S. Pat. App. Pub. No.
2019/0076646 A1 entitled "Securing an Implantable Medical Device In
Position while Reducing Perforations" published on Mar. 14, 2019,
which is incorporated by reference herein in its entirety. Although
two fixation elements 555 are depicted in FIGS. 11-13, it is be
understood that one fixation element or more than two fixation
elements may be used with the illustrative systems and methods
described herein.
[0081] A distance 501 may be defined between where the proximal end
556 of the fixation element 555 is coupled to (e.g., extends from)
the outer lead body 550 and a distal penetration end 524 of the
penetration element 520. The distance 501 may be between about 2
millimeters (mm) and about 15 mm. In one embodiment, the distance
501 may be 4 mm. In one or more embodiments, the distance 501 may
be greater than or equal to 2 mm, greater than or equal to 5 mm,
greater than or equal to 8 mm, etc. and/or less than or equal to 4
mm, less than or equal to 7 mm, less than or equal to 10 mm, less
than or equal to 12 mm etc.
[0082] In some embodiments, the distance 501 may be referred to as
an initial penetration distance because, for example, the force
applied to the inner lead body 560 and penetration element 520 by
the fixation elements 555 being released in the deployed positioned
and "grabbing" tissue may be sufficient to drive the inner lead
body 560 and penetration element 520 into the target location up to
the distal end region 554 of the outer lead body 550. In other
words, the fixation elements 555 may "drive" the inner lead body
560 and penetration element 520 into the tissue across the distance
501.
[0083] Further, a relationship between the distance 501 and the
length and shape of the fixation element 555 (i.e., from the
proximal end 556 to the distal end 558) may be defined to provide
effective penetration to a particular target location. For example,
the length of the fixation elements 555 may be less than the
distance 501 by about 20% or mm to, e.g., allow the penetration
element 530 and the inner lead body 560 (e.g., at least the distal
end 568) to contact and/or penetrate the endocardium prior the
fixation elements 555 contacting the endocardium.
[0084] The outer lead body 550 may include one or more electrodes
within the distal end region 554. In at least one embodiment, the
fixation elements 555 may function as electrodes to, e.g., sense
and or pace right ventricular tissue when the fixation elements 555
are located in the right ventricular endocardium.
[0085] The outer lead body 550 defines an opening extending from
the proximal end region to the distal end region 554, and as shown
in FIGS. 11-13, the inner lead body 560 may be located therein. The
inner lead body 560 may also extend from a proximal end region to a
distal end region 564 and may define an opening extending from the
proximal end region to the distal region 564, within which the
penetration element 520, a guide wire, or stylet may be inserted
(e.g., located therethrough). As shown in FIG. 11, a penetration
element 520 extends from a proximal end to the distal penetration
end 524 and is located in the opening of the inner lead body 560
extending distally from a distal end 568 of the inner lead body
560.
[0086] The system 500 may be configured to restrict, or limit, the
distance 502 that the penetration element 520 may extend beyond the
distal end 568 of the inner lead body 560. The distance 502 may be
defined between the distal end 568 of the inner lead body 560 and
the distal penetration end 524 of the penetration element 520
(e.g., a sharpened point configured for penetration for the right
ventricular endocardium). The distance 502 may be between about 1
millimeter (mm) and about 5 mm. In one embodiment, the distance 502
may be 2 mm. In one or more embodiments, the distance 502 may be
greater than or equal to 1 mm, greater than or equal to 1.5 mm,
greater than or equal to 2.5 mm, etc. and/or less than or equal to
5 mm, less than or equal to 4 mm, less than or equal to 3.5 mm,
less than or equal to 3 mm etc.
[0087] The inner lead body 560 may further include one or more
electrodes 569 that may be configured to be positioned within the
intraventricular septum to sense cardiac electrical activity and
deliver pacing therapy (e.g., cardiac conduction system pacing
therapy, left bundle branch pacing therapy, etc.). Only one of the
electrodes 569 is exposed on FIG. 11.
[0088] Once the outer lead body 550 is fixated to the target
location such as, e.g., the right ventricular endocardial wall, the
inner lead body 560 may be moved relative to the outer lead body
550 to implant the distal end region 564 of the inner lead body 560
within the ventricular septum. More specifically, the outer lead
body 550 may remain relatively stationary as being fixated, or
anchored, to tissue at the target location. The penetration element
520 will have been used to penetrate the target location (e.g., the
right ventricular endocardium), and thus, the inner lead body 560
may then follow the opening made by the penetration element 520
(e.g., tunnel into the opening). First, the penetration element may
be removed (e.g., retracted proximally) from the inner lead body
560. In some embodiments, the inner lead body 560 may then be moved
relative the outer lead body 550 to position to the distal end
region 564 in the desired location for sensing and/or pacing (e.g.,
with the intraventricular septum proximate the left ventricular
endocardium with puncturing or penetrating the left ventricular
endocardium). In other embodiments, a guide wire or stylet may be
inserted through the opening of the inner lead body 560, which may
then be used to position the distal end region 564 of the inner
lead body 560 in the desired location. Additionally, the distal end
region 564 and distal end 568 of the inner lead body 560 may define
a curvature or taper configured to provide tunneling functionality
into tissue and to effectively expand the opening made by the
penetration element 520.
[0089] The inner lead body 560 and the outer lead body 550 are
depicted in FIG. 12 with the penetration element 520 and the
delivery catheter 510 completely removed therefrom. The inner lead
body 560 moved distally away from the outer lead body 550, e.g.,
after the outer lead body 550 is fixated to a target location, is
depicted in FIG. 13. As shown, the inner lead body 560 may also
include, or define, fixation elements 561 configured to fixate, or
fix, the inner lead body 560 within the desired location. In this
embodiment, the fixation elements 561 are configured to provide
"one-way" fixation. Thus, the fixation elements 561 restrict the
inner lead body 560 from moving proximally towards (e.g., back
towards) the outer lead body 550 after the inner lead body 560 has
been moved away (e.g., distally) from the outer lead body 550.
Further, as the inner lead body 560 becomes more exposed, more of
the electrodes 569 along the inner lead body 560 are shown.
[0090] In brief, the lead and delivery system 500 of FIGS. 10-13
may provide for mechanical injection into the intraseptal space. It
may be described that the lead is loaded into a delivery system, a
perforating element is extended out of the distal of the lead and
is shrouded by the catheter. After lead has been positioned in
desired implant location, the lead may be extended out of catheter.
As the lead extends out of catheter, the fixation elements (e.g.,
nitinol tines) may engage the endocardium. Further, as the fixation
elements actuate, they extend the lead out of the delivery system.
Still further, as the lead tip/needle is actuated forward, the lead
is injected into the septum and simultaneously fixated. Then, the
needle may be retracted, and the inner assembly of the lead may
then be tunneled to desired location. In at least one example, to
guide the lead during tunneling, the lead/catheter can be shifted,
and shaped/steerable stylets can be used. Further, the inner and
outer lead assemblies may then be secured.
[0091] An illustrative quadripolar lead 590 that may be used with
the systems and methods described herein is depicted FIG. 14. As
shown, the lead 590 includes four di-pole electrodes 592 spaced
along the length of the lead 590. The electrodes 592 may be spaced
apart between about 1 millimeters (mm) and about 5 mm.
Additionally, the lead 590 includes a plurality of small fixation
elements 594 located between each of the electrodes 592. In one
embodiment, the fixation elements 594 may be flexible, polymer
tines that can fold down in a delivery catheter and can deploy into
to muscle fiber when deployed. Also, when enough force is applied,
the fixation elements 594 will flex and allow removal chronically
(e.g., pulled out of an implant location, moved proximally away
from an implant location).
[0092] In another embodiment, the lead 590 may include a helix or
helical fixation element as opposed to the fixation elements 594
shown in FIG. 14. A helix may allow the lead 590 to be fixated, and
then the inner lead body to be advanced after outer lead body is
fixated.
[0093] In another embodiment, similar to the fixation elements 561
of the inner lead body 560, the fixation elements 594 may be
configured to be predominantly "one-way." In other words, the
fixation elements 594 may restrict proximal movement of the lead
590 more than distal movement of the lead 590 to, e.g., allow for
implantation but restrict dislodgment in the proximal
direction.
[0094] All references and publications cited herein are expressly
incorporated herein by reference in their entirety for all
purposes, except to the extent any aspect directly contradicts this
disclosure.
[0095] All scientific and technical terms used herein have meanings
commonly used in the art unless otherwise specified. The
definitions provided herein are to facilitate understanding of
certain terms used frequently herein and are not meant to limit the
scope of the present disclosure.
[0096] Unless otherwise indicated, all numbers expressing feature
sizes, amounts, and physical properties used in the specification
and claims may be understood as being modified either by the term
"exactly" or "about." Accordingly, unless indicated to the
contrary, the numerical parameters set forth in the foregoing
specification and attached claims are approximations that can vary
depending upon the desired properties sought to be obtained by
those skilled in the art utilizing the teachings disclosed herein
or, for example, within typical ranges of experimental error.
[0097] Terms related to orientation, such as "proximal," "distal,"
or "end," are used to describe relative positions of components and
are not meant to limit the absolute orientation of the embodiments
contemplated.
[0098] The terms "coupled" or "connected" refer to elements being
attached to each other either directly (in direct contact with each
other) or indirectly (having one or more elements between and
attaching the two elements). Either term may be modified by
"operatively" and "operably," which may be used interchangeably, to
describe that the coupling or connection is configured to allow the
components to interact to carry out functionality.
[0099] The singular forms "a," "an," and "the" encompass
embodiments having plural referents unless its context clearly
dictates otherwise.
[0100] The term "or" is generally employed in its inclusive sense,
for example, to mean "and/or" unless the context clearly dictates
otherwise. The term "and/or" means one or all of the listed
elements or a combination of at least two of the listed
elements.
[0101] The phrases "at least one of," "comprises at least one of,"
and "one or more of" followed by a list refers to any one of the
items in the list and any combination of two or more items in the
list.
Illustrative Examples
[0102] Example 1: An implantable medical device comprising:
[0103] a plurality of electrodes comprising: [0104] a right atrial
electrode positionable within the right atrium to deliver cardiac
therapy to or sense electrical activity of the right atrium of the
patient's heart; and [0105] at least one left ventricular electrode
positionable proximate the left ventricle of the patient's
heart;
[0106] a housing extending from a proximal end region to a distal
end region, wherein the right atrial electrode is leadlessly
coupled to the proximal end region;
[0107] a leadlet extending from a proximal region to a distal
region, wherein the proximal region is coupled to the distal end
region of the housing and the at least one ventricular electrode is
coupled to the distal region of the leadlet, wherein the leadlet is
configured to extend through the coronary sinus ostium and into the
coronary sinus or a coronary vein of the patient's heart to
position the least one left ventricular electrode proximate the
left ventricle of the patient's heart;
[0108] a therapy delivery circuit within the housing and operably
coupled to the plurality of electrodes to deliver cardiac therapy
to the patient's heart;
[0109] a sensing circuit within the housing and operably coupled to
the plurality of electrodes to sense electrical activity of the
patient's heart; and
[0110] a controller within the housing and comprising processing
circuitry operably coupled to the therapy delivery circuit and the
sensing circuit, the controller configured to: [0111] monitor
electrical activity using the processing circuitry and one or more
of the plurality of electrodes; and [0112] delivering pacing
therapy using the processing circuitry and one or more of the
plurality of electrodes.
[0113] Example 2. The device as in Example 1, wherein the at least
one left ventricular electrode is implantable into the left
ventricular myocardium from the coronary sinus proximal to the
posterior vein of the patient's heart.
[0114] Example 3. The device as in Example 1, wherein the at least
one left ventricular electrode is implantable into the anterior
interventricular vein of the patient's heart.
[0115] Example 4. The device as in Example 1, wherein the at least
one left ventricular electrode is implantable into the lateral vein
of the patient's heart.
[0116] Example 5. The device as in any one of Examples 1-4, wherein
delivering pacing therapy comprises utilizing field steering to
avoid left atrial capture by the at least one left ventricular
electrode.
[0117] Example 6: A method comprising: [0118] implanting a right
atrial electrode in the right atrial endocardium or in the right
atrial myocardium of a patient's heart, the right atrial electrode
being leadlessly coupled to a proximal end region of an implantable
housing, wherein processing circuitry is disposed in the housing
and operably coupled to the right atrial electrode; [0119]
implanting at least one left ventricular electrode through the
coronary sinus ostium and into the coronary sinus or a coronary
vein of the patient's heart, the at least one left ventricular
electrode being coupled to a distal region of a leadlet, a proximal
region of the leadlet being coupled to a distal end region of the
implantable housing, wherein the processing circuitry is operably
coupled to the at least one left ventricular electrode; [0120]
monitoring electrical activity using the processing circuitry and
one or more of the right atrial electrode and the at least one left
ventricular electrode; and [0121] delivering pacing therapy using
the processing circuitry and at one or more of the right atrial
electrode and the at least one left ventricular electrode.
[0122] Example 7: The method as in Example 6, wherein implanting
the left ventricular electrode comprises implanting the left
ventricular electrode into the left ventricular myocardium from the
coronary sinus proximal to the posterior vein of the patient's
heart.
[0123] Example 8: The method as in Example 6, wherein implanting
the left ventricular electrode comprises implanting the left
ventricular electrode into the anterior interventricular vein of
the patient's heart.
[0124] Example 9: The method as in Example 6, wherein implanting
the left ventricular electrode comprises implanting the left
ventricular electrode into the lateral vein of the patient's
heart.
[0125] Example 10: The method as in any one of Examples 6-9,
wherein delivering pacing therapy comprises utilizing field
steering to avoid left atrial capture by the left ventricular
electrode.
[0126] Example 11: A method comprising: [0127] delivering a
delivery catheter and a penetration element disposed in the
delivery catheter to the right ventricular endocardium of the
interventricular septal wall of a patient's heart; [0128]
puncturing the right ventricular endocardium using the penetration
element to form an opening through the right ventricular
endocardium and into the interventricular septal wall; [0129]
retracting the penetration element; [0130] advancing a distal
portion of a guide element through the delivery catheter and the
opening and into the interventricular septal wall to extend along
the left ventricular endocardial wall; and [0131] delivering a
distal portion of an implantable medical lead over the guide
element to the left ventricular myocardium to extend along the left
ventricular endocardial wall to position at least one left
ventricular electrode on the distal portion in the left ventricular
myocardium.
[0132] Example 12: The method as in Example 11, wherein the at
least one left ventricular electrode is positioned proximate to the
left bundle branch of the conduction system of the patient's
heart.
[0133] Example 13: The method as in any one of Examples 11-12,
further comprising implanting at least one right ventricular
electrode proximate to the right ventricular endocardium, the at
least one right ventricular electrode being positioned proximal to
the at least one left ventricular electrode on the distal portion
of the implantable medical lead.
[0134] Example 14: The method as in Example 13, further comprising:
[0135] monitoring electrical activity of at least one of the at
least one right ventricular electrode and the at least one left
ventricular electrode; and [0136] delivering pacing therapy using
at least one of the at least one right ventricular electrode and
the at least one left ventricular electrode.
[0137] Example 15: The method as in Example 14, wherein delivering
pacing therapy comprises delivering pacing pulses using the at
least one left ventricular electrode to the left bundle branch of
the conduction system of the patient's heart.
[0138] Example 16: The method as in any one of Examples 13-15,
wherein the at least one left ventricular electrode comprises a
plurality of left ventricular electrodes, wherein the at least one
right ventricular electrode comprises a plurality of right
ventricular electrodes.
[0139] Example 17: The method as in any one of Examples 11-16,
wherein the delivery catheter extends from a proximal portion to a
distal portion, wherein the distal portion defines a curvature to
position a distal end of the catheter substantially flush to the
right ventricular endocardium.
[0140] Example 18: The method as in any one of Examples 11-17,
wherein the guide element extends from a proximal region to the
distal region, wherein the distal region comprises a distal
curvature portion that curves when exiting the delivery catheter
into the interventricular septal wall so as to deliver at least a
region of the distal portion of the implantable medical lead
substantially parallel to the interventricular septal wall in the
left ventricular myocardium.
[0141] Example 19: A system for delivering an implantable medical
lead into the interventricular septal wall and proximate the left
ventricular myocardium, the system comprising: [0142] a delivery
catheter extending from a proximal end region to a distal end
region, the distal end region positionable adjacent to the right
ventricular endocardium of the interventricular septal wall of a
patient's heart; [0143] a penetration element disposable in the
delivery catheter to form an opening through the right ventricular
endocardium and into the interventricular septal wall; and [0144] a
guide element extending from a proximal end region to a distal end
region, the guide element disposable in the delivery catheter to
enter the interventricular septal wall through the opening and to
extend along the left ventricular endocardial wall.
[0145] Example 20: The system as in Example 19, wherein the system
further comprises an implantable medical lead comprising at least
one left ventricular electrode and deliverable over the guide
element to the left ventricular myocardium to extend along the left
ventricular endocardial wall to position the at least one left
ventricular electrode in the left ventricular myocardium of the
patient's heart.
[0146] Example 21: The system as in Example 20, wherein the at
least on left ventricular electrode is positioned proximate to the
left bundle branch of the conduction system of the patient's
heart.
[0147] Example 22: The system as in any one of Examples 20-21,
where the implantable medical lead further comprises at least one
right ventricular electrode positionable proximate to the right
ventricular endocardium.
[0148] Example 23: The system as in Example 22, wherein the at
least one left ventricular electrode comprises a plurality of left
ventricular electrodes, wherein the at least one right ventricular
electrode comprises a plurality of right ventricular
electrodes.
[0149] Example 24: The system as in any one of Examples 19-23,
wherein the distal end region of the delivery catheter defines a
curvature to position a distal end of the catheter substantially
flush to the right ventricular endocardium.
[0150] Example 25: The system as in any one of Examples 19-24,
wherein the distal end region of the guide element comprises a
distal curvature portion that curves when exiting the delivery
catheter into the interventricular septal wall so as to deliver at
least a region of the distal portion of the implantable medical
lead substantially parallel to the interventricular septal wall in
the left ventricular myocardium.
[0151] Thus, various embodiments of implantable medical devices for
multi-chamber pacing are disclosed. It should be understood that
various aspects disclosed herein may be combined in different
combinations than the combinations specifically presented in the
description and accompanying drawings. It should also be understood
that, depending on the example, certain acts or events of any of
the processes or methods described herein may be performed in a
different sequence, may be added, merged, or left out altogether
(e.g., all described acts or events may not be necessary to carry
out the techniques). In addition, while certain aspects of this
disclosure are described as being performed by a single module or
unit for purposes of clarity, it should be understood that the
techniques of this disclosure may be performed by a combination of
units or modules associated with, for example, a medical
device.
* * * * *