U.S. patent application number 11/132788 was filed with the patent office on 2005-09-29 for fixed length anchor and pull mitral valve device and method.
Invention is credited to Mathis, Mark L., Nieminen, Gregory D., Reuter, David G..
Application Number | 20050216077 11/132788 |
Document ID | / |
Family ID | 27610485 |
Filed Date | 2005-09-29 |
United States Patent
Application |
20050216077 |
Kind Code |
A1 |
Mathis, Mark L. ; et
al. |
September 29, 2005 |
Fixed length anchor and pull mitral valve device and method
Abstract
A device affects the mitral valve annulus geometry of a heart.
The device includes a first anchor configured to be positioned
within and anchored to the coronary sinus of the heart adjacent the
mitral valve annulus within the heart and a second anchor
configured to be positioned within the coronary sinus of the heart
proximal to the first anchor and adjacent the mitral valve annulus
within the heart. The second anchor, when deployed, anchors against
distal movement and is moveable in a proximal direction. The device
further includes a connecting member having a fixed length
permanently attached to the first and second anchors. As a result,
when the first and second anchors are within the coronary sinus
with the first anchor anchored in the coronary sinus, the second
anchor may be displaced proximally to affect the geometry of the
mitral valve annulus and released to maintain the effect on the
mitral valve geometry.
Inventors: |
Mathis, Mark L.; (Kirkland,
WA) ; Nieminen, Gregory D.; (Bothell, WA) ;
Reuter, David G.; (Bothell, WA) |
Correspondence
Address: |
WILSON SONSINI GOODRICH & ROSATI
650 PAGE MILL ROAD
PALO ALTO
CA
94304-1050
US
|
Family ID: |
27610485 |
Appl. No.: |
11/132788 |
Filed: |
May 18, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11132788 |
May 18, 2005 |
|
|
|
10066426 |
Jan 30, 2002 |
|
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Current U.S.
Class: |
623/2.11 ;
623/2.37 |
Current CPC
Class: |
A61N 2001/0585 20130101;
A61F 2/2448 20130101; A61F 2/246 20130101; A61F 2220/0008 20130101;
A61F 2/2451 20130101; A61F 2/2466 20130101; A61F 2310/00017
20130101; A61F 2/2442 20130101; A61F 2210/0014 20130101; A61N 1/057
20130101; A61F 2310/00023 20130101; A61B 2017/00243 20130101; A61F
2250/0012 20130101 |
Class at
Publication: |
623/002.11 ;
623/002.37 |
International
Class: |
A61F 002/24 |
Claims
We claim the following:
1. A device that affects mitral valve annulus geometry of a heart,
comprising: a first anchor, a second anchor and a connecting
member; said first anchor configured to be anchored in a coronary
sinus; said second anchor configured to be deployed adjacent the
mitral valve annulus; whereby the first anchor is positioned in the
coronary sinus and the second anchor is deployed proximal of the
first anchor to affect and maintain a desired geometry of the
mitral valve annulus.
2. The device of claim 1 wherein the first anchor is anchored
proximal to a crossover point located between a coronary sinus and
the cimcumflex artery.
3. The device of claim 2 wherein the proximal anchor is positioned
in the coronary sinus distal to an ostium of the coronary
sinus.
4. The device of claim 3 wherein the connecting member has an
arcuate configuration.
5. The device of claim 4 wherein a tension applied to the
connecting member affects the geometry of the mitral valve
annulus.
6. The device of claim 5 wherein the tension is applied by applying
a force on the second anchor.
7. The device of claim 6 wherein the device further comprises a
tension applying member releasably coupled to the second
anchor.
8. The device of claim 6 wherein a desired level of tension is
applied in order to affect a concomitant change in the geometry of
the mitral valve annulus.
9. The device of claim 7 wherein the second member is decoupled
from the second anchor after the desired change in mitral valve
geometry is achieved.
10. The device of claim 8 wherein the desired change in the
geometry of the mitral valve annulus is monitored.
11. The device of claim 8 wherein the desired changed in the
geometry of the mitral valve annulus is indicated by a change in a
patient's mitral valve regurgitation.
12. The device of claim 8 wherein change in the geometry of the
mitral valve annulus reduces mitral valve regurgitation.
13. The device of claim 1 wherein the connecting member is
configured to be atraumatic.
14. The device of claim 8 wherein the device further comprises a
covering.
15. The device of claim 1 wherein the first anchor, the second
anchor and connecting members are integral.
16. A device that affects mitral valve annulus geometry of a heart,
comprising: a first anchor configured to be positioned within and
anchored to the coronary sinus adjacent the mitral valve annulus; a
second anchor configured to be positioned proximal to the first
anchor and adjacent the mitral valve annulus; a connecting member
disposed between the first and second anchors, whereby the first
anchor is anchored in the coronary sinus, the second anchor is
displaced proximally to affect the geometry of the mitral valve
annulus and released to maintain the effect on the mitral valve
geometry; an atraumatic covering; and at least one loop disposed on
the proximal or distal anchor.
Description
CROSS-REFERENCE
[0001] This application is a continuation application of Ser. No.
10/066,426 filed Jan. 30, 2002, which is incorporated herein by
reference in its entirety and to which application we claim
priority under 35 USC .sctn. 120.
FIELD OF THE INVENTION
[0002] The present invention generally relates to a device and
method for treating dilated cardiomyopathy of a heart. The present
invention more particularly relates to a device and method for
reshaping the mitral valve annulus.
BACKGROUND OF THE INVENTION
[0003] The human heart generally includes four valves. Of these
valves, a most critical one is known as the mitral valve. The
mitral valve is located in the left atrial ventricular opening
between the left atrium and left ventricle. The mitral valve is
intended to prevent regurgitation of blood from the left ventricle
into the left atrium when the left ventricle contracts. In
preventing blood regurgitation the mitral valve must be able to
withstand considerable back pressure as the left ventricle
contracts.
[0004] The valve cusps of the mitral valve are anchored to muscular
wall of the heart by delicate but strong fibrous cords in order to
support the cusps during left ventricular contraction. In a healthy
mitral valve, the geometry of the mitral valve ensures that the
cusps overlie each other to preclude regurgitation of the blood
during left ventricular contraction.
[0005] The normal functioning of the mitral valve in preventing
regurgitation can be impaired by dilated cardiomyopathy caused by
disease or certain natural defects. For example, certain diseases
may cause dilation of the mitral valve annulus. This can result in
deformation of the mitral valve geometry to cause ineffective
closure of the mitral valve during left ventricular contraction.
Such ineffective closure results in leakage through the mitral
valve and regurgitation. Diseases such as bacterial inflammations
of the heart or heart failure can cause the aforementioned
distortion or dilation of the mitral valve annulus. Needless to
say, mitral valve regurgitation must not go uncorrected.
[0006] One method of repairing a mitral valve having impaired
function is to completely replace the valve. This method has been
found to be particularly suitable for replacing a mitral valve when
one of the cusps has been severely damaged or deformed. While the
replacement of the entire valve eliminates the immediate problem
associated with a dilated mitral valve annulus, presently available
prosthetic heart valves do not possess the same durability as
natural heart valves.
[0007] Various other surgical procedures have been developed to
correct the deformation of the mitral valve annulus and thus retain
the intact natural heart valve function. These surgical techniques
involve repairing the shape of the dilated or deformed valve
annulus. Such techniques, generally known as annuloplasty, require
surgically restricting the valve annulus to minimize dilation.
Here, a prosthesis is typically sutured about the base of the valve
leaflets to reshape the valve annulus and restrict the movement of
the valve annulus during the opening and closing of the mitral
valve.
[0008] Many different types of prostheses have been developed for
use in such surgery. In general, prostheses are annular or
partially annular shaped members which fit about the base of the
valve annulus. The annular or partially annular shaped members may
be formed from a rigid material, such as a metal, or from a
flexible material.
[0009] While the prior art methods mentioned above have been able
to achieve some success in treating mitral regurgitation, they have
not been without problems and potential adverse consequences. For
example, these procedures require open heart surgery. Such
procedures are expensive, are extremely invasive requiring
considerable recovery time, and pose the concomitant mortality
risks associated with such procedures. Moreover, such open heart
procedures are particularly stressful on patients with a comprised
cardiac condition. Given these factors, such procedures are often
reserved as a last resort and hence are employed late in the mitral
regurgitation progression. Further, the effectiveness of such
procedures is difficult to assess during the procedure and may not
be known until a much later time. Hence, the ability to make
adjustments to or changes in the prostheses to obtain optimum
effectiveness is extremely limited. Later corrections, if made at
all, require still another open heart surgery.
[0010] An improved therapy to treat mitral regurgitation without
resorting to open heart surgery has recently been proposed. This is
rendered possible by the realization that the coronary sinus of a
heart is near to and at least partially encircles the mitral valve
annulus and then extends into a venous system including the great
cardiac vein. As used herein, the term "coronary sinus" is meant to
refer to not only the coronary sinus itself but in addition, the
venous system associated with the coronary sinus including the
great cardiac vein. The therapy contemplates the use of a device
introduced into the coronary sinus to reshape and advantageously
affect the geometry of the mitral valve annulus.
[0011] The device includes a resilient member having a cross
sectional dimension for being received within the coronary sinus of
the heart and a longitudinal dimension having an unstressed arched
configuration when placed in the coronary sinus. The device
partially encircles and exerts an inward pressure on the mitral
valve. The inward pressure constricts the mitral valve annulus, or
at least a portion of it, to essentially restore the mitral valve
geometry. This promotes effective valve sealing action and
eliminates mitral regurgitation.
[0012] The device may be implanted in the coronary sinus using only
percutaneous techniques similar to the techniques used to implant
cardiac leads such as pacemaker leads. One proposed system for
implanting the device includes an elongated introducer configured
for being releasably coupled to the device. The introducer is
preferably flexible to permit it to advance the device into the
heart and into the coronary sinus through the coronary sinus
ostium. To promote guidance, an elongated sheath is first advanced
into the coronary sinus. Then, the device and introducer are moved
through a lumen of the sheath until the device is in position
within the coronary sinus. Because the device is formed of
resilient material, it conforms to the curvatures of the lumen as
it is advanced through the sheath. The sheath is then partially
retracted to permit the device to assume its unstressed arched
configuration. Once the device is properly positioned, the
introducer is then decoupled from the device and retracted through
the sheath. The procedure is then completed by the retraction of
the sheath. As a result, the device is left within the coronary
sinus to exert the inward pressure on the mitral valve to restore
mitral valve geometry.
[0013] The foregoing therapy has many advantages over the
traditional open heart surgery approach. Since the device, system
and method may be employed in a comparatively noninvasive
procedure, mitral valve regurgitation may be treated at an early
stage in the mitral regurgitation progression. Further, the device
may be placed with relative ease by any minimally invasive
cardiologist. Still further, since the heart remains completely
intact throughout the procedure, the effectiveness of the procedure
may be readily determined. Moreover, should adjustments be deemed
desirable, such adjustments may be made during the procedure and
before the patient is sent to recovery.
[0014] Another approach to treat mitral regurgitation with a device
in the coronary sinus is based upon the observation that the
application of a localized force against a discrete portion of the
mitral valve annulus can terminate mitral regurgitation. This
suggests that mitral valve dilation may be localized and
nonuniform. Hence, the device applies a force to one or more
discrete portions of the atrial wall of the coronary sinus to
provide localized mitral valve annulus reshaping instead of
generalized reshaping of the mitral valve annulus. Such localized
therapy would have all the benefits of the generalized therapy. In
addition, a localized therapy device may be easier to implant and
adjust.
[0015] A still further approach to treat mitral regurgitation from
the coronary sinus of the heart contemplates a device having a
first anchor configured to be positioned within and fixed to the
coronary sinus of the heart adjacent the mitral valve annulus
within the heart, a cable fixed to the first anchor and extending
proximally from the first anchor within the heart, a second anchor
configured to be positioned in and fixed in the heart proximal to
the first anchor and arranged to slidingly receive the cable, and a
lock that locks the cable on the second anchor. When the first and
second anchors are fixed within the heart, the cable may be drawn
proximally and locked on the second anchor. The geometry of the
mitral valve is thereby affected. This approach provides
flexibility in that the second anchor may be positioned and fixed
in the coronary sinus or alternatively, the second anchor may be
positioned and fixed in the right atrium. This approach further
allows adjustments in the cable tension after implant. The present
invention provides a still further alternative for treating mitral
regurgitation with a device placed in the coronary sinus adjacent
to the mitral valve annulus.
SUMMARY OF THE INVENTION
[0016] The present invention provides a device that affects mitral
valve annulus geometry of a heart. The device includes a first
anchor configured to be positioned within and anchored to the
coronary sinus of the heart adjacent the mitral valve annulus
within the heart, and a second anchor configured to be positioned
within the heart proximal to the first anchor and adjacent the
mitral valve annulus within the heart. The device further includes
a connecting member having a fixed length permanently attached to
the first and second anchors. As a result, when the first and
second anchors are within the heart with the first anchor anchored
in the coronary sinus, the second anchor may be displaced
proximally to affect the geometry of the mitral valve annulus and
released to maintain the effect on the mitral valve geometry. The
second anchor may be configured, when deployed, to anchor against
distal movement but be moveable proximally to permit the second
anchor to be displaced proximally within the coronary sinus.
[0017] The first anchor and the second anchor are preferably
self-deploying upon release in the coronary sinus or may be
deployable after placement. Further, the connecting member, in
being of fixed length, has a maximum extended length and as such
may be a rigid member, have an initial arcuate configuration,
include a spring, having a maximum length or be flexible but not
stretchable.
[0018] The present invention further provides a device for
affecting mitral valve annulus geometry of a heart. The device
includes first anchor means for anchoring in the coronary sinus of
the heart adjacent the mitral valve annulus, and second anchor
means for being deployed within the heart proximal to the first
anchor means and adjacent the mitral valve annulus, and connecting
means having a fixed length and permanently connecting the first
anchor means to the second anchor means. As a result, when the
first and second anchor means are within the heart with the first
anchor means anchored in the coronary sinus, the second anchor
means may be displaced proximally for cooperating with the first
anchor means and the connecting means for affecting the geometry of
the mitral valve annulus and released for maintaining the effect on
the mitral valve geometry.
[0019] The invention further provides a system that affects mitral
valve annulus geometry of a heart. The system includes a mitral
valve device including a first anchor configured to be positioned
within and anchored to the coronary sinus of the heart adjacent the
mitral valve annulus within the heart, a second anchor configured
to be positioned within the heart proximal to the first anchor and
adjacent the mitral valve annulus within the heart, and a
connecting member having a fixed length permanently attached to the
first and second anchors.
[0020] The system further includes a catheter having a distal end,
a proximal end and a lumen that receives the device, the catheter
being guidable into the coronary sinus adjacent to the mitral valve
annulus and deploying the first and second anchors of the device
within the coronary sinus adjacent to the mitral valve annulus, and
a tether releasably coupled to the second anchor and extending
proximally through the lumen and out of the catheter proximal end.
As a result, when the first anchor is deployed by the catheter in
the coronary sinus, the second anchor may be displaced proximally
by proximally pulling on the tether to affect the geometry of the
mitral valve annulus and thereafter released for deployment to
maintain the effect on the mitral valve geometry.
[0021] The present invention further provides a method of affecting
mitral valve annulus geometry in a heart. The method includes the
steps of fixing a first anchor within the coronary sinus of the
heart adjacent to the mitral valve annulus, positioning a second
anchor within the coronary sinus adjacent to the mitral valve
annulus and proximal to the first anchor, fixing a fixed length
connecting member between the first anchor and the second anchor,
displacing the second anchor proximally to affect the geometry of
the mitral valve annulus, and releasing the second anchor from
further proximal displacement to maintain the effect on the mitral
valve geometry.
[0022] The present invention further provides a device that affects
mitral valve annulus geometry of a heart. The device includes a
first anchor configured to be positioned within and anchored to the
coronary sinus of the heart adjacent the mitral valve annulus
within the heart, a second anchor configured to be positioned
within the heart proximal to the first anchor and adjacent the
mitral valve annulus within the heart, and a connecting member
attached between the first and second anchors. At least one of the
first and second anchors anchoring against movement in a first
direction and being moveable in a second direction opposite the
first direction.
[0023] The at least one anchor may be the first anchor wherein the
first direction is a proximal direction and wherein the second
direction is a distal direction. The at least one anchor may be the
second anchor wherein the first direction is a distal direction and
wherein the second direction is a proximal direction. In a
preferred embodiment, the first anchor anchors against movement in
a proximal direction and is moveable in a distal direction and the
second anchor anchors against movement in the distal direction and
is moveable in the proximal direction.
[0024] The invention still further provides a device that affects
mitral valve annulus geometry of a heart and which permits a
cardiac lead to be implanted in the left side of the heart. The
device includes a first anchor configured to be positioned within
and anchored to the coronary sinus of the heart adjacent the mitral
valve annulus within the heart, a second anchor configured to be
positioned within the heart proximal to the first anchor and
adjacent the mitral valve annulus within the heart, and a
connecting member attached between the first and second anchors.
The first anchor is configured to occupy less than all of the
coronary sinus to permit a cardiac lead to be passed by the first
anchor.
[0025] The first anchor may include a loop through which the
cardiac lead may be passed. The second anchor may be positionable
within the coronary sinus and be configured to occupy less than all
of the coronary sinus to permit the cardiac lead to be passed by
the second anchor. The second anchor may also include a loop
through which the cardiac lead may be passed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The features of the present invention which are believed to
be novel are set forth with particularity in the appended claims.
The invention, together with further aspects and advantages
thereof, may best be understood by making reference to the
following description taken in conjunction with the accompanying
drawings, in the several figures of which like reference numerals
identify identical elements, and wherein:
[0027] FIG. 1 is a superior view of a human heart with the atria
removed;
[0028] FIG. 2 is a superior view of a human heart similar to FIG. 1
illustrating a deployed mitral valve device embodying the present
invention;
[0029] FIG. 3 is a superior view of a human heart similar to FIG. 2
illustrating a first step in the deployment of the mitral valve
device of FIG. 2 embodying the present invention;
[0030] FIG. 4 is a view similar to FIG. 3 illustrating a further
step in the deployment of the device of FIG. 2;
[0031] FIG. 5 is a view similar to FIG. 3 illustrating a final step
in the deployment of the device of FIG. 2;
[0032] FIG. 6 is a superior view of a human heart similar to FIG. 1
illustrating another deployed mitral valve device embodying the
present invention; and
[0033] FIG. 7 is a side view with a portion broken away
illustrating further details of device anchors and the manner in
which they permit an implantable lead to pass thereby.
DETAILED DESCRIPTION OF THE INVENTION
[0034] Referring now to FIG. 1, it is a superior view of a human
heart 10 with the atria removed to expose the mitral valve 12, the
coronary sinus 14, the coronary artery 15, and the circumflex
artery 17 of the heart 10 to lend a better understanding of the
present invention. Also generally shown in FIG. 1 are the pulmonary
valve 22, the aortic valve 24, and the tricuspid valve 26 of the
heart 10.
[0035] The mitral valve 12 includes an anterior cusp 16, a
posterior cusp 18 and an annulus 20. The annulus encircles the
cusps 16 and 18 and maintains their spacing to provide a complete
closure during a left ventricular contraction. As is well known,
the coronary sinus 14 partially encircles the mitral valve 12
adjacent to the mitral valve annulus 20. As is also known, the
coronary sinus is part of the venous system of the heart and
extends along the AV groove between the left atrium and the left
ventricle. This places the coronary sinus essentially within the
same plane as the mitral valve annulus making the coronary sinus
available for placement of the mitral valve therapy device of the
present invention therein.
[0036] FIG. 2 shows a mitral valve therapy device 30 embodying the
present invention. As may be noted in FIG. 2, the device 30
includes a first anchor 32, a connecting member 34, and a second
anchor 36. The anchors 32 and 36 and the connecting member 34 may
be formed from the same material to provide an integral
structure.
[0037] The first anchor 32 is located at the distal end of the
device 30. The anchor 32 is hook-shaped so as to be self-deployable
when released in the coronary sinus 14. More specifically, the
device 30 may be formed of most any biocompatible material such as
stainless steel, Nitinol, a nickel/titanium alloy of the type well
known in the art having shape memory or plastic. The hook-shaped
configuration of the anchor 32 thus expands when released to wedge
against the inner wall of the coronary sinus 14 for anchoring or
fixing the anchor 32 against at least proximal movement. The anchor
32 may however allow distal movement. Preferably, the anchor 32 is
positioned just proximally to the crossover point 19 of the
coronary sinus 14 and a circumflex artery 17.
[0038] The connecting member 34, by being formed of Nitinol, is
relatively rigid and is predisposed to have an arcuate
configuration to generally correspond to the shape of the mitral
valve annulus 20. The connecting member 34 is of a fixed length and
is permanently attached to the first and second anchors 32 and 36.
Here it will be noted that the second anchor is positioned within
the coronary sinus just distal to the ostium 21 of the coronary
sinus 14. The second anchor 36 may have a similar hook-shaped
configuration and is also preferably self-expanding to be
self-deployable. The hook-shape of the anchor 36 anchors or fixes
the anchor 36 against distal movement but permits the anchor to be
pulled proximally. This is a particularly significant aspect of the
device 30 because it permits the device to be adjusted after the
anchors 32 and 36 are first deployed.
[0039] When the device 30 is deployed as shown in FIG. 2, the first
anchor 32 is fixed against proximal movement within the coronary
sinus 14. The connecting member 34 then extends proximally from the
first anchor 32 to the second anchor 36. The second anchor 36 is
then positioned in its desired location within the coronary sinus
14 proximal to the first anchor 32 and permitted to self-expand for
being anchored against distal movement. Then, the second anchor 36
is pulled proximally while the first anchor 32 is held in its fixed
position. This creates tension in the connecting member 34 to
affect the geometry of the mitral valve annulus 20. Once a desired
amount of tension is applied to the connecting member 34, the
second anchor 36 is released from further movement and is
redeployed against distal movement. With the connecting member 34
now under maintained tension, the advantageously affected geometry
of the mitral valve annulus 20 is now preserved. The tension in the
cable is preferably adjusted by the pulling on the second anchor 26
while monitoring a parameter indicative of mitral regurgitation,
such as Doppler echo.
[0040] The connecting member 34 may be provided with a covering
(not shown). The covering may preferably be formed of a
compressible material to serve to cushion the forces of the
connecting member applied against the inner wall of the coronary
sinus 14.
[0041] FIGS. 3 through 5 show a manner in which the device 30 may
be deployed by a deployment assembly 50. As will be noted in FIG.
3, the deployment assembly 50 includes a catheter 52 and a tether
54. The catheter 52 has a lumen 56 dimensioned for slidably
receiving the device 30 in its predeployed state with the tether 54
looped around the second anchor 36 and extending out the proximal
end of the catheter 52.
[0042] As will be noted in FIG. 3, the first anchor 32 has been
deployed while the second anchor remains in the catheter lumen 56.
This may be accompanied by feeding the catheter 52 into the
coronary sinus until the first anchor is in a desired position.
Now, the catheter 52 may be moved proximally while maintaining the
first anchor 32 against movement. Proximal movement of the catheter
52 will release the anchor 32. When the anchor is released, it will
self-expand to self-deploy and be fixed against proximal
movement.
[0043] As shown in FIG. 4, the catheter 52 is further retracted to
release the second anchor 36 to permit it to self-expand and to
self-deploy. The second anchor 36 is now fixed against distal
movement but permitted to move proximally. The tether 54 continues
to extend out the proximal end of the catheter 52.
[0044] As may now be further seen in FIG. 5, tension is then
applied to the connecting member 34 by proximally pulling on the
tether 54, and hence the second anchor 36, while the first anchor
32 resists proximal movement. When the desired tension is placed on
the connecting member 34, the second anchor 36 is released for
re-self-deployment. When this is completed, the first anchor 32 and
the second anchor 36 are fixed in position with a tension in the
connecting member 34. The catheter 52 and the tether 54 may then be
removed to complete the deployment process. Although the proximal
anchor 36 is shown to be finally deployed in the coronary sinus, it
will be appreciated by those skilled in the art that the proximal
anchor 36, after being displaced proximally, may finally be
deployed within the right atrium just proximal to the ostium 21 of
the coronary sinus 14. Hence, any final position of the proximal
anchor 36 proximal to the distal anchor 32 and within the heart is
contemplated in accordance with the present invention.
[0045] In accordance with the present invention, the device 30 may
be deployed in a slightly different manner as described above.
Here, the first anchor 32 may be deployed as described above and
the second anchor 36 left in the catheter 52 as it is moved
proximally. When the second anchor 36 reaches a desired position,
the catheter 52 may then be pulled back to release and deploy the
second anchor 36. As a result, in accordance with this alternative
embodiment, the second anchor, when deployed, may anchor against
both distal and proximal movement.
[0046] FIG. 6 shows another mitral valve device 70 embodying the
present invention. The device 70 is similar to the device 30
previously described except that its connecting member 74 includes
a spring configuration 75. The spring 75 has a maximum length and
serves to more forcefully maintain the applied tension on the
mitral valve annulus 20. To this end, the device 70 includes a
first anchor 72, the connecting member 74, and a second anchor
76.
[0047] The first and second anchors 72 and 76 are again configured
so that when they are released, they self-expand, to wedge against
the inner wall of the coronary sinus 14. Again, the first anchor
resists proximal movement and the second anchor 76 resists distal
movement. In all other respects, the device 70 may be identical to
and deployed in the same manner as the device 30.
[0048] Implantable cardiac stimulation devices are well known in
the art. Such devices may include, for example, implantable cardiac
pacemakers and defibrillators. The devices are generally implanted
in a pectoral region of the chest beneath the skin of a patient
within what is known as a subcutaneous pocket. The implantable
devices generally function in association with one or more
electrode carrying leads which are implanted within the heart. The
electrodes are usually positioned within the right side of the
heart, either within the right ventricle or right atrium, or both,
for making electrical contact with their respective heart chamber.
Conductors within the leads and a proximal connector carried by the
leads couple the electrodes to the device to enable the device to
sense cardiac electrical activity and deliver the desired
therapy.
[0049] Traditionally, therapy delivery had been limited to the
venous, or right side of the heart. The reason for this is that
implanted electrodes can cause blood clot formation in some
patients. If a blood clot were released arterially from the left
heart, as for example the left ventricle, it could pass directly to
the brain potentially resulting in a paralyzing or fatal stroke.
However, a blood clot released from the right heart, as from the
right ventricle, would pass into the lungs where the filtering
action of the lungs would prevent a fatal or debilitating embolism
in the brain.
[0050] Recently, new lead structures and methods have been proposed
and even practiced for delivering cardiac rhythm management therapy
to the left heart. These lead structures and methods avoid direct
electrode placement within the left atrium and left ventricle of
the heart by lead implantation within the coronary sinus of the
heart. As previously mentioned, the phrase "coronary sinus" refers
to not only the coronary sinus itself but in addition, the venous
system associated with the coronary sinus including the great
cardiac vein.
[0051] It has been demonstrated that electrodes placed in the
coronary sinus region of the heart may be used for left atrial
pacing, left ventricular pacing, or cardioversion and
defibrillation. These advancements enable implantable cardiac
stimulation devices to address the needs of a patient population
with left ventricular dysfunction and/or congestive heart failure
which would benefit from left heart side pacing, either alone or in
conjunction with right heart side pacing (bi-chamber pacing),
and/or defibrillation.
[0052] Even though the device of the present invention is
implantable in the coronary sinus of the heart, it is configured in
accordance with further aspects of the present invention to permit
a cardiac lead to pass through the coronary sinus for functioning
as described above. To that end, and as best seen in FIG. 7, the
anchors 32 and 36 of the device 30 occupy only a small portion of
and hence less than all of the interior space of the coronary sinus
14. This permits a cardiac lead 80 to be advanced into the coronary
sinus 14 for implant in the left side of the heart.
[0053] More specifically, the anchors 32 and 36 take the form of
loops 33 and 35 respectively which are then bent backwards on the
device to form the previously referred to hook-shapes for
self-deployment. The loops 33 and 35 thus permit the cardiac lead
80 to be passed therethrough for implant in the left heart. This is
particularly desirable because many patients suffering from mitral
regurgitation may also be candidates for left heart cardiac rhythm
management therapy.
[0054] While particular embodiments of the present invention have
been shown and described, modifications may be made, and it is
therefore intended in the appended claims to cover all such changes
and modifications which fall within the true spirit and scope of
the invention as defined by the appended claims.
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