U.S. patent application number 10/972049 was filed with the patent office on 2005-06-23 for myocardial lead.
This patent application is currently assigned to Cardiac Pacemakers, Inc.. Invention is credited to Coe, M. Sean, Heil, Ronald W. JR., Kelley, Peter T., Palme, Donald F. II, Shiroff, Jason Alan, Westlund, Randy W., Yingling, David B..
Application Number | 20050137672 10/972049 |
Document ID | / |
Family ID | 34528512 |
Filed Date | 2005-06-23 |
United States Patent
Application |
20050137672 |
Kind Code |
A1 |
Coe, M. Sean ; et
al. |
June 23, 2005 |
Myocardial lead
Abstract
The present invention is a lead for use in connection with a
myocardial lead attachment system of the type having an anchor for
engaging the heart and a tether extending from the anchor. The lead
includes a lead body having a proximal end, a distal end and a
lumen for accepting the tether. A tapered tip is separate from the
lead and positioned adjacent the distal end of the lead. The tip
has a longitudinal through-hole for accepting the tether.
Inventors: |
Coe, M. Sean; (Plymouth,
MN) ; Heil, Ronald W. JR.; (Roseville, MN) ;
Kelley, Peter T.; (Buffalo, MN) ; Shiroff, Jason
Alan; (Shoreview, MN) ; Westlund, Randy W.;
(River Falls, WI) ; Palme, Donald F. II;
(Princeton, MN) ; Yingling, David B.; (Stillwater,
MN) |
Correspondence
Address: |
JASON R. KRAUS
FAEGRE & BENSON, LLP
2200 WELLS FARGO CENTER
90 SOUTH SEVENTH STREET
MINNEAPOLIS
MN
55402-3901
US
|
Assignee: |
Cardiac Pacemakers, Inc.
St. Paul
MN
|
Family ID: |
34528512 |
Appl. No.: |
10/972049 |
Filed: |
October 22, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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60514037 |
Oct 24, 2003 |
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60514665 |
Oct 27, 2003 |
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60514042 |
Oct 24, 2003 |
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60514714 |
Oct 27, 2003 |
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60514039 |
Oct 24, 2003 |
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60514146 |
Oct 24, 2003 |
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60514038 |
Oct 24, 2003 |
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60514713 |
Oct 27, 2003 |
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Current U.S.
Class: |
607/126 ;
607/122 |
Current CPC
Class: |
A61B 2017/0417 20130101;
A61B 2017/0608 20130101; A61N 1/0587 20130101; A61N 2001/0578
20130101; A61B 5/296 20210101; A61B 2017/06042 20130101; A61N
1/0568 20130101; A61N 2001/058 20130101; A61B 17/0469 20130101;
A61B 17/06109 20130101 |
Class at
Publication: |
607/126 ;
607/122 |
International
Class: |
A61N 001/05 |
Claims
We claim:
1. A lead for use in connection with a myocardial lead attachment
system of the type having an anchor for engaging the heart and a
tether extending from the anchor, the lead including: a lead body
having a proximal end, a distal end and a lumen for accepting the
tether; and a tapered tip separate from the lead and positioned
adjacent the distal end of the lead body, wherein the tip has a
longitudinal through-hole for accepting the tether.
2. The lead of claim 1 wherein the tip is coupled to the distal end
of the lead body.
3. The lead of claim 1 wherein the tip is free from fixed
connection to the lead.
4. The lead of claim 1 wherein the tip has a reduced diameter in a
direction from a proximal end to a distal end to reduce trauma to
the heart as the lead is advanced through the myocardium.
5. The lead of claim 4 wherein the tip is cone shaped.
6. The lead of claim 4 wherein the tip is bullet shaped.
7. The lead of claim 1 wherein the tip is made from a dissolvable
material.
8. The lead of claim 7 wherein the tip is formed from a
water-soluble material.
9. The lead of claim 7 wherein the tip is formed from one of sugar,
mannitol or polyethylene glycol.
10. The lead of claim 7 wherein a period of time necessary to
dissolve the tip is less than a period of time in which scar tissue
forms about the tip.
11. The lead of claim 7 further comprising a fixation mechanism
coupled to the distal end of the lead, wherein the tip has an
opening to receive the fixation mechanism and retain the fixation
mechanism in a retracted configuration and upon dissolution of the
tip the fixation mechanism deploys to an expanded
configuration.
12. The lead of claim 7 wherein the tip includes a therapeutic drug
for release as the tip dissolves.
13. The lead of claim 12 wherein the therapeutic drug is a
steroid.
14. The lead of claim 1 wherein the tip is formed from a
therapeutic drug-eluting material.
15. The lead of claim 14 wherein the drug is a steroid.
16. The lead of claim 1, further comprising a therapeutic drug
attached to an outer surface of a portion of the lead body.
17. The lead of claim 16 wherein the therapeutic drug is a
steroid.
18. The lead of claim 16 wherein the drug is attached onto an
implanted portion of the lead.
19. The lead of claim 1 wherein the tip is formed from an ablatable
material.
20. The lead of claim 1 further comprising: a lock housing on the
lead; and a lock formed on a distal end of the tether and lock
having a first diameter, wherein the tip through-hole has an
internal diameter smaller than the lock first diameter.
21. A method of implanting a myocardial lead, the method
comprising: advancing an anchor mechanism coupled to a distal end
of a tether through the myocardium to an implant site; selecting an
appropriate dilating tip having an internal through-hole; threading
the tip and lead onto the tether such that the tip is distal to the
lead; and advancing the tip and lead over the tether to the implant
site.
22. The method of claim 21 further comprising coupling the tip to a
distal end of the lead.
23. The method of claim 21 further comprising allowing the tip to
dissolve.
24. The method of claim 23 wherein threading the tip and lead onto
the tether further comprises inserting a fixation mechanism coupled
to a distal end of the lead into an opening in the tip in a
retracted configuration and dissolving the tip further includes
allowing the fixation mechanism to deploy to an expanded
configuration.
25. The method of claim 23 further comprising releasing a
therapeutic drug from the tip as the tip dissolves.
26. A method of implanting a lead into a myocardium of a heart, the
method comprising: attaching a proximal end of an anchor mechanism
and tether arrangement to a needle; advancing the needle through
the heart at least until the proximal end of the tether 45 exits
the heart; detaching the needle from the tether; tensioning the
proximal end of the tether to cause the anchor mechanism to engage
the heart; and advancing a lead over the tether into the heart.
Description
REFERENCES
[0001] The present application claims the benefit of the following
U.S. Provisional Applications: Application Ser. No. 60/514,037
filed Oct. 24, 2003, entitled "Absorbable Myocardial Lead Fixation
System", Application Ser. No. 60/514,665 filed Oct. 27, 2003,
entitled "Lead Electrode Arrangement for Myocardial Leads",
Application Ser. No. 60/514,042 filed Oct. 24, 2003, entitled
"Tapered Tip for Myocardial Lead", Application Ser. No. 60/514,714
filed Oct. 27, 2003, entitled "Minimally-Invasive Fixation Systems
for Over-the-Tether Myocardial Leads", Application Ser. No.
60/514,039 filed Oct. 24, 2003, entitled "Distal or Proximal
Fixation of Over-the-Suture Myocardial Leads", Application Ser. No.
60/514,146 filed Oct. 24, 2003, entitled "Myocardial Lead with
Fixation Mechanism", Application Ser. No. 60/514,038 filed Oct. 24,
2003 entitled "Delivery Instrument for Myocardial Lead Placement"
and Application Ser. No. 60/514,713 filed Oct. 27, 2003, entitled
"Drug-Eluting Myocardial Leads", all of which are incorporated
herein by reference.
[0002] Reference is hereby made to the following commonly assigned
U.S. patent application Ser. No. 10/821,421, filed Apr. 9, 2004,
entitled "Cardiac Electrode Anchoring System" and the following
commonly assigned U.S. patent applications filed on an even date
herewith, all of which are incorporated herein by reference:
application Ser. No. ______, entitled "Myocardial Lead Attachment
System", application Ser. No. ______, entitled "Distal or Proximal
Fixation of Over-the-Tether Myocardial Leads", application Ser. No.
______, entitled "Myocardial Lead with Fixation Mechanism" and
application Ser. No. ______, entitled "Absorbable Myocardial Lead
Fixation System."
FIELD OF THE INVENTION
[0003] This invention relates generally to implantable lead
assemblies for stimulating and/or sensing electrical signals in
muscle tissue. More particularly, it relates to
myocardially-implanted leads for cardiac stimulation and systems
for anchor the leads.
BACKGROUND OF THE INVENTION
[0004] Cardiac rhythm management systems are used to treat heart
arrhythmias. Pacemaker systems are commonly implanted in patients
to treat bradycardia (i.e., abnormally slow heart rate). A
pacemaker system includes an implantable pulse generator and leads,
which form the electrical connection between the implantable pulse
generator and the heart. An implantable cardioverter defibrillator
("ICD") is used to treat tachycardia (i.e., abnormally rapid heart
rate). An ICD also includes a pulse generator and leads that
deliver electrical energy to the heart.
[0005] The leads coupling the pulse generator to the cardiac muscle
are commonly used for delivering an electrical pulse to the cardiac
muscle, for sensing electrical signals produced in the cardiac
muscle, or for both delivering and sensing. The leads are
susceptible to categorization according to the type of connection
they form with the heart. An endocardial lead includes at least one
electrode at or near its distal tip adapted to contact the
endocardium (i.e., the tissue lining the inside of the heart). An
epicardial lead includes at least one electrode at or near its
distal tip adapted to contact the epicardium (i.e., the tissue
lining the outside of the heart). Finally, a myocardial lead
includes at least one electrode at or near its distal tip inserted
into the heart muscle or myocardium (i.e., the muscle sandwiched
between the endocardium and epicardium). Some leads have multiple
spaced apart distal electrodes at differing polarities and are
known as bipolar type leads. The spacing between the electrodes can
affect lead performance and the quality of the electrical signal
transmitted or sensed through the heart tissue.
[0006] The lead typically consists of a flexible conductor
surrounded by an insulating tube or sheath that extends from the
electrode at the distal end to a connector pin at the proximal end.
Endocardial leads are typically delivered transvenously to the
right atrium or ventricle and commonly employ tines at a distal end
for engaging the trabeculae.
[0007] The treatment of congestive heart failure ("CHF"), however,
often requires left ventricular stimulation either alone or in
conjunction with right ventricular stimulation. For example,
cardiac resynchronization therapy ("CRT") (also commonly referred
to as biventricular pacing) is an emerging treatment for heart
failure, which requires stimulation of both the right and the left
ventricle to increase cardiac output. Left ventricular stimulation
requires placement of a lead in or on the left ventricle near the
apex of the heart. One technique for left ventricular lead
placement is to expose the heart by way of a thoracotomy. The lead
is then positioned so that the electrodes contact the epicardium or
are embedded in the myocardium. Another method is to advance an
epicardial lead endovenously into the coronary sinus and then
advance the lead through a lateral vein of the left ventricle. The
electrodes are positioned to contact the epicardial surface of the
left ventricle.
[0008] Unfortunately, insertion through the myocardium can be
somewhat traumatic to the muscle tissue. Accordingly, there is a
need for a lead that can be implanted with minimal long-term damage
to the physiology of the heart.
SUMMARY OF THE INVENTION
[0009] According to one embodiment, the present invention is a lead
for use in connection with a myocardial lead attachment system of
the type having an anchor for engaging the heart and a tether
extending from the anchor. The lead includes a lead body having a
proximal end, a distal end and a lumen for accepting the tether. A
tapered tip is separate from the lead body and is positioned
adjacent the distal end of the lead body. The tip has a
longitudinal through-hole for accepting the tether.
[0010] According to another embodiment, the present invention is a
method of implanting a myocardial lead. An anchor mechanism coupled
to a distal end of a tether is advanced through the myocardium to
an implant site. An appropriate dilating tip having an internal
through-hole is selected. The tip and lead are threaded onto the
tether such that the tip is distal to the lead. The tip and lead
are advanced over the tether to the implant site.
[0011] According to another embodiment, the present invention is a
method of implanting a lead into a myocardium of a heart. A
proximal end of an anchor mechanism and tether arrangement is
attached to a needle. The needle is advanced through the heart at
least until the proximal end of the tether 45 exits the heart. The
needle is detached from the tether and the proximal end of the
tether is tensioned to cause the anchor mechanism to engage the
heart. A lead is advanced over the tether into the heart.
[0012] This summary is not intended to describe each embodiment or
every implementation of the present invention. Advantages and a
more complete understanding of the invention will become apparent
upon review of the detailed description and claims in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a sectional view of a patient's heart showing a
portion of the vasculature and a myocardial lead attachment and
pacing system according to one embodiment of the present
invention.
[0014] FIG. 2 is a side sectional view of a distal portion of the
myocardial lead attachment system of FIG. 1 in accordance with one
embodiment of the present invention.
[0015] FIG. 3 is a side sectional view of a distal portion of the
myocardial lead attachment system of FIG. 1 in accordance with
another embodiment of the present invention.
[0016] FIG. 4 is a side sectional view of a distal portion of the
myocardial lead attachment system of FIG. 1 in accordance with yet
another embodiment of the present invention.
[0017] FIG. 5 is a side sectional view of a distal portion of the
myocardial lead attachment system of FIG. 1 in accordance with
still another embodiment of the present invention.
[0018] FIG. 6A is a side sectional view of a distal portion of the
myocardial lead attachment system of FIG. 1 in accordance with
another embodiment of the present invention.
[0019] FIG. 6B is a side sectional view of the attachment system of
FIG. 6A following removal of the tip.
[0020] FIG. 7 is a perspective view of a distal portion of the
myocardial lead attachment system of FIG. 1 in accordance with yet
another embodiment of the present invention.
[0021] While the invention is amenable to various modifications and
alternative forms, specific embodiments have been shown by way of
example in the drawings and are described in detail below. The
intention, however, is not to limit the invention to the particular
embodiments described. On the contrary, the invention is intended
to cover all modifications, equivalents, and alternatives falling
within the scope of the invention as defined by the appended
claims.
DETAILED DESCRIPTION
[0022] FIG. 1 shows a myocardial lead attachment and pacing system
10 deployed in a human heart 12 according to one embodiment of the
present invention. The heart 12 includes a right atrium 14 and a
right ventricle 16 separated from a left atrium 18 and a left
ventricle 20 by a septum 22. During normal operation of the heart
12, deoxygenated blood is fed into the right atrium 14 through the
superior vena cava 24 and the inferior vena cava 26. The
deoxygenated blood flows from the right atrium 14 into the right
ventricle 16. The deoxygenated blood is pumped from the right
ventricle 16 into the lungs, where the blood is re-oxygenated. From
the lungs the oxygenated blood flows into the left atrium 18, then
into the left ventricle 20. The left ventricle 20 beats forcefully
to pump the oxygenated blood throughout the body.
[0023] The outer walls of the heart 12 are lined with a tissue
known as the epicardium 28. The inner walls of the heart are lined
with a tissue known as the endocardium 30. The heart muscle, or
myocardium 32, is sandwiched between the endocardium 30 and the
epicardium 28. A tough outer pericardial sac 33 surrounds the heart
12.
[0024] The pacing system 10 includes a pulse generator 34 coupled
to a myocardial lead 36. The pulse generator 34 is typically
implanted in a pocket formed underneath the skin of the patient's
chest or abdominal region. The lead 36 extends from the pulse
generator 34 to the heart 12 and is implanted in the myocardium 32
near an apex 38 of the left ventricle 20. The lead 36 delivers
electrical signals from the pulse generator 34 to at least one
electrode located at or near a distal region of the lead 36 to
accomplish pacing of the heart 12 (not visible in FIG. 1). Although
shown in implanted near the apex 38, the lead 36 may be implanted
anywhere in the heart 12 pacing therapy is needed. An anchor
mechanism 44 is coupled to the lead 36 via a tether 45 to secure
the lead 36 to the heart 12 and to facilitate delivery of the lead
36 into the heart 12.
[0025] The pacing lead assembly 36 and anchor mechanism 44 may be
implanted in the heart 12 with a delivery instrument and according
to methods described in the above-identified application
"Myocardial Lead Attachment System". Briefly, the delivery
instrument and anchor mechanism 44 are advanced through the heart
12, forming a tract through the myocardium 32 (not visible in FIG.
1). The anchor mechanism 44 is deployed on a surface of the heart
12 so that the tether 45 extends longitudinally through the tract.
Following implantation of the anchor mechanism 44, the tether 45 is
threaded through the lead 36 and the lead 36 is advanced over the
tether 45 into the myocardium 32. The tether 45 is then tensioned
and attached to the lead 36 to secure the lead 36 in place within
the myocardium 32. This structure results in a locally-stable
myocardial implant.
[0026] Optionally, the anchor mechanism 44 may be implanted without
the aid of a delivery instrument as is described above, but rather
with a curved suture needle. The proximal end of the tether 45 is
attached to the needle, either directly or to a short length of
suture attached to the needle. The needle is used to pierce the
epicardium 28, is pushed through the myocardium 32 and drawn back
through the epicardium 28, pulling the tether 45 through the
myocardium 32. The tether 45 is cut from the needle and tensioned
to bring the anchor mechanism 44 in contact with the epicardium 28.
The lead 36 is threaded onto the tether 45 and advanced over the
tether 45 as previously described.
[0027] FIG. 2 is a sectional view of a distal portion of the
myocardial lead attachment system 10 according to one embodiment of
the present invention. The myocardial lead 36 includes two
electrodes, a proximal anode 40a and a distal cathode 40b. An outer
insulating sheath 46 is formed around the lead 36 and protects a
pair of coiled conductive members 48a and 48b coupled to the anode
40a and cathode 40b, respectively. A second inner insulating sheath
50 forms an internal lumen 43 for receiving the tether 45. A marker
band 52 is optionally formed on the outer insulating sheath 46.
[0028] The lead 36 includes a tapered tip 54 positioned distal to
the distal region 42 of the lead 36. The tapered tip 54 tapers from
a first diameter a at a proximal end 54a to a second diameter b,
smaller than the first diameter a, at a distal end 54b. In one
embodiment, as shown in FIG. 2, the tapered tip 54 is formed in the
shape of a cone. In another embodiment, shown in FIG. 3, the tip 54
is more rounded and is formed in the shape of a bullet. A bore 56
extends through the tip 54 in communication with the lumen 43 for
receiving the tether 45.
[0029] As the lead 36 is advanced over the tether 45 through the
during insertion, the tapered tip 54 does not cut through the
myocardial tissue 32, but rather dissects or dilates the tissue.
The tapered tip 54 provides a streamlined leading edge to the lead
36, reducing trauma to the myocardium 32. According to one
embodiment, the diameter a of the proximal end 54a is greater than
a diameter of the lead 36. Such a tip 54 gently dilates or expand
the tract to facilitate advancement of the lead 36. According to
other embodiments, the tip 54 has any shape having rounded edges
and a streamlined shape chosen to reduce trauma to the myocardium
32 during insertion.
[0030] Prior to lead implantation, the tip 54 may be selected from
a plurality of tips having differing shapes based on the physiology
of the heart 12. Where the epicardium 28 and or pericardium 33 are
generally undisturbed and in relatively healthy condition, the more
bullet shaped tip of the embodiment shown in FIG. 3 is sufficient
to facilitate advancement of the lead 36. However, sometimes the
epicardium 28 and/or pericardium 33 have been damaged, either by
disease or previous trauma, resulting in the presence of tough
adhesions or scar tissue. The more pointed cone shaped tip 54 of
the embodiment shown in FIG. 2 may be required to effectively
traverse such adhesions or scar tissue. Prior to inserting the lead
36, the surgeon may evaluate the implant site and select an
appropriate tip 54, i.e. pointed or blunt, as deemed necessary to
pierce the epicardium 28 and or pericardium 33 and dilate the tract
through the heart 12 to facilitate insertion of the lead 36.
[0031] According to one embodiment, as shown in FIGS. 2 and 3, the
tapered tip 54 is configured to securely couple with the blunt
distal tip 42 of the lead 36. According to one embodiment, the
diameter a of the proximal end 54a of the tip 54 is sized to
receive the distal tip 42 of the lead 36. According to other
embodiments, the tip 54 and distal tip 42 of the lead 36 are
provided with complementary threads for rotational coupling, or are
provided with a complementary interlock or other structure for
coupling.
[0032] FIG. 4 shows another embodiment, in which the tapered tip 54
is positioned adjacent to the distal tip 42 of the pacing lead 36
without securely coupling to the lead 36. The tapered tip 54 rides
along the tether 45 in front of the lead 36 to facilitate the lead
36 in passing through the myocardium 32. A tip 54 according to the
present embodiment may be used in conjunction with any such
commercially available myocardial lead. According to another
embodiment, the tapered tip 54 is integrally formed at the distal
end 42 of the lead 36.
[0033] FIG. 5 shows another embodiment in which the system is
further provided with a lock 60 and lock housing 61 as is described
in the above-identified application "Distal or Proximal Fixation of
Over-the-Tether Myocardial Leads". The tip bore 56 has a diameter c
greater than the diameter of the tether 45 such that the tip 54
easily passes over the tether 45, but smaller than a diameter of
the lock 60 formed on the tether 45. The tip 54 and lead 36 are
easily threaded over the tether 45 and advanced along the tether
45. When the tip 54 contacts the lock 60, the tip 54 and lead 36
are prevented from advancing further along the tether 45. The
tapered tip 54 is used to prevent the lead 36 from advancing over
the lock 60, and to provide spacing between the lead 36 and the
anchor mechanism 44.
[0034] According to another embodiment, the tip 54 is made from a
water-soluble material, such that the tip 54 will dissolve upon
placement within the myocardium 32. The tip 54 may be made from any
biocompatible, water-soluble material known in the art, such as a
sugar. In one embodiment, the tip 54 is made from mannitol. In
another embodiment, the tip 54 is made from polyethylene glycol
("PEG"). The molecular weight of the PEG can be selected to achieve
a desired dissolution time of the tapered tip 54. In yet another
embodiment, additives known in the art are used to further control
the dissolution time. According to another embodiment, the tip 54
is made of an ablatable material.
[0035] A dissolvable tip 54 reduces the amount of foreign matter
located in the heart 12 following dissolution. This may reduce
irritation in the heart 12, as well as the formation of scar
tissue. Addition of the tip 54 does not increase the overall size
of the lead 36 chronically implanted in the heart 12. Following
dissolution of the tip 54, the lead 36 may be advanced over the
lock 60 to mate the lock 60 with the lock housing 61. In addition,
the dissolved portion of the dissolving tip 54 provides a
lubricating coating or film within the tract to further facilitate
passage of the lead 36.
[0036] FIGS. 6A and 6B show another embodiment of the lead 36, in
which a fixation mechanism 62 is provided at the distal tip 42 of
the lead 36. Such a fixation mechanism 62 facilitates fixation of
the lead 36 to myocardial tissue 32. The above-identified
application "Myocardial Lead with Fixation Mechanism" describes
various fixation mechanisms suitable for use with a lead 36
according to the present embodiment. The tapered tip 54 is
dissolvable as previously described and is configured to mate with
the fixation mechanism 62. According to one embodiment, the
fixation mechanism 62 is received in the tip bore 56.
[0037] Throughout insertion of the lead 36 into the heart 12, the
tapered tip 54 facilitates passage of the lead 36 through the tract
and masks the fixation mechanism 62, which may include sharp edges
or points. Upon dissolution of the tip 54, the fixation mechanism
62 is revealed and operable to retain the lead 36 in a stable
position. According to one embodiment, the fixation mechanism 62 is
retained in the tip bore 56 in a first collapsed or retracted
configuration, as is shown in FIG. 6A. Following dissolution of the
tip 54, the fixation mechanism 62 deploys to a second expanded
configuration, as is shown in FIG. 6B.
[0038] According to another embodiment, the tip 54 contains a
pharmaceutical additive to treat implant trauma. Such an additive
may be provided to reduce myocardial irritation or inflammation.
This pharmaceutical additive may administer a "bolus" therapeutic
agent to treat the implant trauma. In one embodiment, the tip 54 is
made of a dissolvable material as described above but which also
includes a steroid (or other therapeutic drug) released as the tip
54 dissolves. According to another embodiment, the tip 54 is formed
of a material provided with a coating that is drug eluting. The tip
54 may be chosen to have an appropriate amount of steroid (or other
therapeutic drug) for a particular situation.
[0039] In one embodiment, pharmaceutical additives as previously
described are provided on other portions of the lead 36 in addition
to or instead of the tip 54. In one embodiment, the drug eluting
feature is provided as one or more discrete steroid/polymeric rings
or collars 64 positioned on the lead 36 to contact the myocardium
32 upon implantation and anchoring (See FIG. 2). In another
embodiment, the implanted portion of the lead 20 is coated with a
drug (e.g., steroid) eluting coating, such as a paint stripe (not
shown). In another embodiment, shown in FIG. 7, a polymeric lead
body tubing 66 may be fashioned from a steroid-loaded polymer
composite. In each of these embodiments, a therapeutic amount of
steroid is included on the implanted portion of the lead 36.
[0040] Various controlled-release techniques known in the art may
be incorporated into these embodiments to deliver the therapeutic
drug in the right amount and with the right time distribution.
[0041] Various modifications and additions can be made to the
exemplary embodiments discussed without departing from the scope of
the present invention. Accordingly, the scope of the present
invention is intended to embrace all such alternative,
modifications, and variations as fall within the scope of the
claims, together with all equivalents thereof.
* * * * *