US-12623071-B2 - Substernal electrical stimulation system

Abstract

Implantable cardiac pacing systems and methods for providing substernal pacing are described. In one example, a cardiac pacing system includes a pacemaker implanted in a patient and an implantable medical electrical lead. The implantable medical electrical lead includes an elongated lead body having a proximal end and a distal portion, a connector configured to couple to the pacemaker at the proximal end of the elongated lead body, and one or more electrodes along the distal portion of the elongated lead body, wherein the distal portion of the elongated lead body of the lead is implanted substantially within an anterior mediastinum of the patient and the pacemaker is configured to deliver pacing pulses to a heart of the patient.

Inventors

• Amy E. Thompson-Nauman
• Melissa G.T. Christie
• Rick D. McVenes

Assignees

• MEDTRONIC, INC.

Dates

Publication Date

20260512

Application Date

20220428

Claims (17)

1. 1 . A cardiac pacing system comprising: a pulse generator configured to provide cardiac pacing therapy; an implantable medical electrical lead that includes: a lead body having a proximal end and a distal portion; a connector configured to couple to the pulse generator at the proximal end of the lead body; and a plurality of electrodes on the distal portion of the lead body, wherein the distal portion of the lead body of the lead is configured to be positioned within the substernal space of the patient and the pulse generator is configured to deliver pacing pulses to an atrium of a heart of the patient using at least a first pair of electrodes of the plurality of electrodes and deliver pacing pulses to a ventricle of the heart of the patient via at least a second pair of electrodes of the plurality of electrodes, the first pair of electrodes and the second pair of electrodes being electrically coupled to a therapy circuitry of the pulse generator, the first pair of electrodes and the second pair of electrodes being positioned on the distal portion of the lead body that is configured to be positioned within the substernal space, the first pair of electrodes being spaced apart from the second pair of electrodes such that the first pair of electrodes are configured to deliver pacing pulses to the atrium of the heart of the patient and the second pair of electrodes are configured to deliver pacing pulses to the ventricle of the heart of the patient, wherein a distance between the first pair electrodes and the second pair of electrodes is greater than a distance between each electrode of the first pair of electrodes.
2. 2 . The system of claim 1 , wherein the pulse generator is configured to provide one of bradycardia pacing, antitachycardia (ATP) pacing, and post-shock pacing to the patient via the lead.
3. 3 . The system of claim 1 , wherein the distal portion of the lead is configured to be positioned within the substernal space such that the second pair of electrodes-is located over a cardiac silhouette of the ventricle of the heart as observed via an anterior-posterior (AP) fluoroscopic view of the heart or the first pair of electrodes-is located over a cardiac silhouette of the atrium of the heart as observed via an anterior-posterior (AP) fluoroscopic view of the heart.
4. 4 . The system of claim 1 , wherein the first pair of electrodes is located along the lead body such that when the distal portion of the lead body is positioned within the substernal space, the first pair of electrodes-is located over a cardiac silhouette of the atrium of the heart as observed via an anterior-posterior (AP) fluoroscopic view of the heart to pace the atrium of the heart via the delivery of the pacing pulses, and wherein the second pair of electrodes is located along the lead body such that when the distal portion of the lead body is positioned within the substernal space, the second pair of electrodes-is located over a cardiac silhouette of the ventricle of the heart as observed via the AP fluoroscopic view of the heart to pace the ventricle of the heart via the delivery of the pacing pulses.
5. 5 . The system of claim 1 , wherein the pulse generator is configured to deliver pacing pulses having pulse widths greater than or equal to two (2) milliseconds.
6. 6 . The system of claim 1 , wherein the pulse generator is configured to deliver pacing pulses having pulse widths between two (2) and three (3) milliseconds.
7. 7 . The system of claim 1 , wherein the pulse generator is configured to deliver pacing pulses having pulse widths between approximately one and a half (1.5) milliseconds and twenty (20) milliseconds.
8. 8 . The system of claim 1 , wherein the pulse generator is configured to deliver pacing pulses having pulse widths greater than two (2) milliseconds and less than eight (8) milliseconds.
9. 9 . The system of claim 1 , wherein the pulse generator is configured to deliver pacing pulses having pulse amplitudes between approximately one (1) and twenty (20) volts.
10. 10 . The system of claim 1 , wherein the pulse generator includes a conductive housing that functions as an electrode and the pulse generator is configured to deliver pacing pulses between the plurality of electrodes on the lead and the electrode formed by the conductive housing.
11. 11 . The system of claim 1 , wherein the distal portion of the lead body of the lead is configured to be positioned within the substernal space such that at least a portion of the distal portion is underneath a ribcage of the patient.
12. 12 . The system of claim 1 , wherein the distal portion of the lead body of the lead is configured to be positioned within the substernal space such that at least a portion of the distal portion is between a ribcage of the patient and a pericardium of the patient.
13. 13 . A method comprising: generating one or more pacing pulses with a pulse generator; and delivering the one or more pacing pulses via a plurality of electrodes including at least a first pair of electrodes and a second pair of electrodes of an implantable medical electrical lead to a heart of the patient the implantable medical electrical lead including: a lead body having a proximal end and a distal portion; and the first pair of electrodes and the second pair of electrodes on the distal portion of the lead body, the first pair of electrodes being spaced apart from the second pair of electrodes such that the first pair of electrodes are configured to deliver pacing pulses to the atrium of the heart of the patient and the second pair of electrodes are configured to deliver pacing pulses to the ventricle of the heart of the patient, wherein a distance between the first pair electrodes and the second pair of electrodes is greater than a distance between each electrode of the first pair of electrodes, wherein, during the delivery of the pacing pulses, the distal portion of the lead body of the lead is positioned within the substernal space of the patient such that the plurality of electrodes are physically isolated from a pericardium of the patient.
14. 14 . The method of claim 13 , wherein, during the delivery of the pacing pulses, the distal portion of the lead body of the lead is positioned within the substernal space such that at least a portion of the lead body is underneath a ribcage of the patient.
15. 15 . The method of claim 13 , wherein, during the delivery of the pacing pulses, the distal portion of the lead body of the lead is positioned within the substernal space such that at least a portion of the lead body is between a ribcage of the patient and a pericardium of the patient.
16. 16 . The method of claim 13 , wherein, during the delivery of the pacing pulses, the distal portion of the lead body of the lead is positioned within the substernal space such that at least a portion of the lead body is offset laterally from a center of a sternum of the patient.
17. 17 . The method of claim 13 further comprising: anchoring, via one or more anchoring mechanisms positioned along the lead body, the lead body to loose connective tissue or structures of the anterior mediastinum such that the plurality of electrodes are physically isolated from the pericardium of the patient.

Description

This application is a continuation of U.S. application Ser. No. 16/725,458, filed Dec. 23, 2019 (issued as U.S. Pat. No. 11,344,720), which is a divisional of U.S. application Ser. No. 14/261,479, filed Apr. 25, 2014 (issued as U.S. Pat. No. 10,532,203), which claims the benefit of U.S. Provisional Application No. 61/820,033, filed on May 6, 2013. The content of each of these applications is incorporated herein by reference in its entirety. FIELD OF THE INVENTION The present application relates to electrical stimulation devices, systems and/or methods for providing substernal electrical stimulation, including substernal cardiac pacing. BACKGROUND OF THE INVENTION Implantable pulse generators have been utilized to provide electrical stimulation to various organs, tissues, muscle, nerves or other features of a patient's body. One example of electrical stimulation provided to a patient is cardiac pacing. Cardiac pacing electrically stimulates the heart when the heart's natural pacemaker and/or conduction system fails to provide synchronized atrial and ventricular contractions at appropriate rates and intervals for a patient's needs. When a patient's heart is beating too slow, bradycardia pacing increases the rate at which the patient's heart contracts to provide relief from symptoms associated with bradycardia. Cardiac pacing may also provide electrical overdrive stimulation intended to suppress or convert tachyarrhythmias, again supplying relief from symptoms and preventing or terminating arrhythmias that could lead to sudden cardiac death or need to be treated with high voltage defibrillation or cardioversion shocks. Pacemakers typically require at least two electrodes to deliver electrical stimulation therapy to the heart and to sense electrical activity of the heart. Traditionally, pacemaker systems are comprised of an implantable pulse generator (or pacemaker) coupled to one or more leads. The lead(s) include one or more electrodes on a distal portion of the lead that are implanted inside the heart such that at least one electrode touches the endocardium. In other examples, the one or more leads can be implanted on the epicardial surface of the heart. SUMMARY OF THE INVENTION The present application is directed to implantable cardiac pacing systems and methods for providing substernal pacing. In one embodiment, a cardiac pacing system includes a pacemaker implanted in a patient and an implantable medical electrical lead. The implantable medical electrical lead includes an elongated lead body having a proximal end and a distal portion, a connector configured to couple to the pacemaker at the proximal end of the elongated lead body, and one or more electrodes along the distal portion of the elongated lead body, wherein the distal portion of the elongated lead body of the lead is implanted substantially within an anterior mediastinum of the patient and the pacemaker is configured to deliver pacing pulses to a heart of the patient. In another embodiment, a method comprises generating one or more stimulation pulses with an implantable pulse generator and delivering the one or more stimulation pulses via at least one electrode of an implantable medical electrical lead implanted at least partially within the anterior mediastinum. This summary is intended to provide an overview of the subject matter described in this disclosure. It is not intended to provide an exclusive or exhaustive explanation of the techniques as described in detail within the accompanying drawings and description below. Further details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the statements provided below. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a front view of patient 12 implanted with implantable medical system 10. FIG. 1B is a side view of patient 12 with implantable medical system 10. FIG. 1C is a transverse view of patient 12 with implantable medical system 10. FIG. 2A is a front view of patient 12 implanted with implantable cardiac pacing system 40. FIG. 2B is a side view of patient 12 with implantable cardiac pacing system 40. FIG. 3A is a front view of patient 12 implanted with implantable cardiac pacing system 50. FIG. 3B is a transverse view of patient 12 with implantable cardiac pacing system 50. FIG. 4 is a functional block diagram of an example configuration of electronic components of an example implantable pulse generator 14. FIG. 5 is a graph illustrating strength-duration curves showing the capture thresholds obtained at various pulse widths during a first acute study. FIG. 6 is a graph illustrating strength-duration curves showing the capture thresholds obtained at various pulse widths during a second acute study. FIG. 7 is a graph illustrating strength-duration curves of electrical data from a third acute experiment. FIG. 8 is a graph illustrating strength-duration c