Implantable defibrillation device

Abstract

An implantable medical device (IMD) comprising: an elongated body comprising: a distal section comprising a fixation mechanism configured to affix the distal section to wall tissue within a first chamber of a heart, a proximal section, and a medial section connecting the distal section to the proximal section, wherein the proximal section is configured to be disposed within a second chamber of the heart or a blood vessel connected to the heart when the distal section is affixed to the first chamber; signal generation circuitry; a first electrode disposed on or around the distal section; a second electrode disposed on or around the proximal section; and processing circuitry disposed within the elongated body, the processing circuitry being configured to: cause the signal generation circuitry to transmit a defibrillation pulse between the first electrode and the second electrode through cardiac tissue of the heart.

Description

IMPLANTABLE DEFIBRILLATION DEVICE

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 711,972, filed October 25, 2024, the entire content of which is incorporated herein by reference.TECHNICAL FIELD

[0002] The disclosure relates to medical devices, and more particularly to implantable cardiac devices.BACKGROUND

[0003] Various types of implantable medical devices (IMDs) have been implanted for treating or monitoring one or more conditions of a patient. Such IMDs may be adapted to monitor or treat conditions or functions relating to heart, muscle, nerve, brain, stomach, endocrine organs or other organs and their related functions. Such IMDs may be associated with leads that position electrodes at a desired location or may be leadless with electrodes integrated with and / or attached to the device housing. These IMDs may have the ability to wirelessly transmit data either to another device implanted in the patient or to another instrument located externally of the patient, or both.A cardiac device may include an IMD configured to deliver therapy signals to the heart to restore a more normal heart rhythm. Such IMDs sense the electrical activity of the heart, and deliver therapy signals based on the sensed electrical activity, via electrodes. Some IMDs are implanted with a distance from the heart and coupled to one or more leads that intravascularly extend into the heart to position electrodes with respect to cardiac tissue.SUMMARY

[0004] In general, this disclosure is directed to implantable medical devices (IMDs) configured to sense and deliver electrical signals to tissue of a patient via a plurality of electrodes. More particularly, this disclosure is directed to IMDs configured to deliver defibrillation shock signals to cardiac tissue of the patient.

[0005] In some examples, a single IMD is wholly implanted within vasculature of the patient. The IMD may define an elongated body within a distal section, a proximal section,and a medial section connecting the distal and proximal sections. The distal section of the IMD may be disposed within one chamber of a heart of the patient and is able to sense signals from and / or deliver therapy signals (e.g., defibrillation signals, pacing signals) to wall tissue of the chamber. The proximal section may be disposed within another chamber of the heart and / or within a blood vessel connected to the heart. The proximal section may be able to sense signals from and / or deliver therapy signals to tissue around the proximal section. Each of the distal section or the proximal section may define a corresponding defibrillation electrode (e.g., a shock coil). The IMD may transmit a defibrillation signal between the defibrillation electrodes to defibrillate cardiac tissue of the patient.

[0006] The distal section and the proximal section may each define a rigid body configured to house electronic components (e.g., processing circuitry, signal generation circuitry, power source(s)) of the IMD. The medial section connecting the distal and proximal sections may be flexible, e.g., thereby allowing the distal and proximal sections to be implanted at different locations within the heart and / or the vasculature of the patient. The flexible medial portion may allow for movement of the IMD with the movement of the heart within the patient.

[0007] The IMD may sense signals from the patient and determine, based on the sensed signals, whether to deliver one or more of a pacing signal or a defibrillation signal to the patient. The IMD may sense signals from electrode(s) and / or sensor(s) disposed on or within one or more of the distal section, the medial section, or the proximal section. The IMD may determine whether to deliver one or more of the pacing signal or the defibrillation signal to one or more target locations within the heart based on one or more of a electrical stability of one or more chambers of the heart or a hemodynamic status of the patient.

[0008] The IMD described herein may provide several advantages over other implantable defibrillators. The IMD may be entirely disposed within the vasculature of the patient, which may reduce patient discomfort and / or reduce visibility of the IMD.Containing the components of the IMD within the elongated body may reduce a number of leads connecting signal generating components of the IMD (e.g., signal generation circuitry) to signal delivery elements of the IMD (e.g., electrodes, defibrillation electrodes). Containing the components of the IMD within the elongated body and disposing the IMD entirely within the vasculature of the patient may eliminate a need foran extravascular IMD, which may reduce a complexity and / or a risk of failure of the IMD, and pocket or device related infections. The design of the IMD may allow the IMD to be implanted at different sites within the heart and / or blood vessels connected to the heart, which may allow for the IMD to be used for a range of different cardiac applications. Implantation of the IMD within the vasculature of the patient may eliminate a need for a subcutaneous pocket for the IMD, which may eliminate a potential source of infection.

[0009] The IMD described herein may deliver therapy signals at locations within the heart and / or closer to cardiac tissue than other IMDs, which may allow the IMD to deliver therapy signals at lower amplitudes to achieve a same efficacy. The IMD may also increase a distance between electrodes (e.g., compared to other IMDs), which may allow for the delivery of lower-amplitude therapy signals to achieve an efficacious result within the patient (e.g., pacing capture, returning the heart to a regular cardiac cycle). The ability to achieve efficacious results with lower-amplitude therapy signals may improve the lifespan of the IMD, reduce an overall profile of the IMD (e.g., by allowing for the use of smaller and lower-power components within IMD), and / or reduce patient discomfort. The IMD may be configured to deliver either pacing or defibrillation signals to the patient based on patient status (e.g., hemodynamic stability, etc.), which may reduce a number of unnecessary shocks delivered to the patient, thereby reducing patient discomfort.

[0010] In some examples, the configuration improves the efficacy of the ATP (antitachycardia pacing) therapy delivered by the IMD. The IMD may thus attempt to deliver as many sequences of ATP as possible if the patient is still hemodynamically stable and the ventricular tachy-arrhythmia is not accelerated. A majority of the tachy-arrhythmia will self-terminate during ATP delivery or be stopped by the ATP therapy, thereby reducing a number of defibrillation shock signals delivered by the IMD to the patient. The reduction in the number of defibrillation shock signals delivered by the IMD may increase a lifespan of the IMD.

[0011] In some examples, this disclosure is directed to an implantable medical device (IMD) comprising: an elongated body extending along a longitudinal axis and comprising: a distal section comprising a fixation mechanism configured to affix the distal section to wall tissue within a first chamber of a heart of the patient, a proximal section, and a medial section connecting the distal section to the proximal section, wherein the elongated body is configured to be entirely disposed within the vasculature of a patient, and wherein theproximal section is configured to be disposed within a second chamber of the heart or a blood vessel connected to the heart when the distal section is affixed to the first chamber; signal generation circuitry disposed within the elongated body; a first electrode disposed on or around the distal section and coupled to the signal generation circuitry; a second electrode disposed on or around the proximal section and coupled to the signal generation circuitry; and processing circuitry disposed within the elongated body, the processing circuitry being configured to: cause the signal generation circuitry to transmit a defibrillation pulse between the first electrode and the second electrode through cardiac tissue of the heart.

[0012] In some examples, this disclosure is directed to a method comprising: advancing a distal section of an elongated body an implantable medical device (IMD) into first chamber of a heart of a patient, wherein the IMD comprises: the elongated body, wherein the elongated body defines the distal section comprising a fixation mechanism, a proximal section, and a medial section connecting the distal section to the proximal section; signal generation circuitry disposed within the elongated body; processing circuitry disposed within the elongated body; a first electrode disposed on or around the distal section and coupled to the signal generation circuitry; and a second electrode disposed on or around the proximal section and coupled to the signal generation circuitry; affixing the distal section to wall tissue of the first chamber via the fixation mechanism; advancing the proximal section of the elongated body into one of a second chamber of the heart or a blood vessel connected to the heart; and causing, by the processing circuitry, the signal generation circuitry to transmit a defibrillation shock pulse to cardiac tissue of the heart via the first electrode and the second electrode.

[0013] In some examples, this disclosure is directed to an implantable medical device (IMD) comprising: an elongated body extending along a longitudinal axis and comprising: a distal section comprising a fixation mechanism configured to affix the distal section to wall tissue within a chamber of a heart of a patient, a proximal section, and a medial section connecting the distal section to the proximal section; signal generation circuitry disposed within the elongated body; processing circuitry disposed within the elongated body; a first electrode disposed on or around the distal section and coupled to the signal generation circuitry; and a second electrode disposed on or around the proximal section and coupled to the signal generation circuitry, wherein the IMD is configured to beentirely disposed within a vasculature of a patient, and wherein the proximal section is configured to be disposed within one of : a superior vena cava (SVC) of the patient, an inferior vena cava (IVC) of the patient, or a coronary sinus of the patient when the distal section is affixed to the chamber, and wherein the processing circuitry is configured to: cause the signal generation circuitry to transmit a defibrillation shock pulse between the first electrode and the second electrode and into cardiac tissue of the heart.

[0014] 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 methods and systems described in detail within the accompanying drawings and description below.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The details of one or more examples of this disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of this disclosure will be apparent from the description and drawings, and from the claims.

[0016] FIG. 1 A is a conceptual diagram illustrating an example device implanted in the heart of a patient, in accordance with one or more aspects of this disclosure.

[0017] FIG. IB is a conceptual diagram illustrating another example device implanted in the heart of the patient.

[0018] FIG. 1C is a conceptual diagram illustrating another example device implanted in the heart of the patient.

[0019] FIG. 2A is a perspective diagram illustrating a side view of the example device of FIG. 1A.

[0020] FIG. 2B is a perspective diagram illustrating a side view of the example device of FIG. IB.

[0021] FIG. 2C is a perspective diagram illustrating a side view of the example device of FIG. 1C.

[0022] FIG. 2D is a perspective diagram illustrating another example of the device of FIGS. 1A-1C.

[0023] FIG. 3 A is a perspective diagram illustrating an example delivery system for the device of FIGS. 1A-2D.

[0024] FIG. 3B is a perspective diagram illustrating the example delivery system of FIG. 3 A after implantation of a distal section of the device.

[0025] FIG. 4 is a conceptual diagram illustrating implantation of the device of any of FIGS. 1 A-2D via the example delivery system of FIGS. 3A-3B.

[0026] FIG. 5 is a block diagram illustrating an example configuration of an example device of any of FIGS. 1-4.

[0027] FIG. 6 is a flowchart illustrating an example process for delivering defibrillation signals to a heart of a patient via an example device of any of FIGS. 1-5.DETAILED DESCRIPTION

[0028] In general, this disclosure is directed to implantable medical devices (IMDs). More particularly, this disclosure is directed to IMDs configured to deliver therapy signals (e.g., defibrillation signals, pacing signals) to a heart of the patient. While the IMD described below is primarily described as being wholly implanted within the vasculature of the patient, the IMD may be at least partially disposed within an epicardial region of the patient or may be implanted within another body lumen of the patient.

[0029] FIG. 1 A is a conceptual diagram illustrating an example device 104A (alternatively referred to herein as “IMD 104 A”) implanted in heart 102 of a patient, in accordance with one or more aspects of this disclosure. Device 104A may include a distal section 110A implanted within one chamber of heart 102, a proximal section 116A disposed within a blood vessel 120 of the patient, and a medial section 114 connecting distal section 110A to proximal section 116A. Any of the example devices described herein (e.g., any of devices 104A-D) may be alternatively referred to as “device 104”.

[0030] Distal section 110A may be implanted within heart 102 at target location 106A within heart 102. In the example illustrated in FIG. 1 A, distal section 110A is disposed within a right ventricle (RV) of heart 102 and target location 106A is located along septum 108 of heart 102. In some examples, distal section 110A may be disposed within another chamber of heart 102 (e.g., right atrium (RA), left atrium (LA), left ventricle (LV)) and target location 106A may be located at another position within heart 102. For example, target location 106A may be located at or around a Triangle of Koch within the RA, a Bundle of His, high septum, left bundle branch, left bundle branch area, or conduction system of the patient.

[0031] Distal section 110A may be a rigid body, e.g., may define a rigid housing. At least some components of device 104A may be disposed within the rigid body of distal section 110A. For example, one or more power sources of device 104A may be disposed within distal section 110A. Distal section 110A may include one or more electrodes (e.g., defibrillation electrode(s) such as shock coil(s), an electrically active surface of distal section 110A) disposed on, distal to, or proximal to distal section 110A (e.g., on medial section 114 but close to distal section 110A). Distal section 110A may deliver cardiac pacing signals (e.g., brady pacing, VF induction pacing, post-shock pacing, and ATP, etc.) to heart 102 at or around target location 106A via electrode(s) on distal section 110A.

[0032] Distal section 110A may include one or more fixation elements disposed at or around a distal end of a housing of distal section 110A. The one or more fixation elements may engage with wall tissue of heart 102 at or around target location 106A, e.g., to affix distal section 110A to the wall tissue. The one or more fixation elements may include, but are not limited to, fixation tine(s), fixation barb(s), fixation heli(ces), or the like. In some examples, distal section 110A is affixed to the wall tissue via passive fixation, e.g., via tines embedded in the ventricular trabeculae. In some examples, electrode(s) of distal section 110A are disposed on the one or more fixation elements and may be distal to the distal end of the housing of distal section 110A.

[0033] In some examples, the one or more fixation elements may be formed from an absorbable material (e.g., an absorbable polymer, an absorbable metal such as Zinc or Magnesium). Once device 104A is disposed within the vasculature, the absorbable material may absorb body fluids of the patient, e.g., to increase fixation of device 104A within the vasculature.

[0034] Proximal section 116A may be disposed within a chamber of heart 102 or blood vessel 120 connected to heart 102. In some examples, where proximal section 116A is disposed within heart 102, proximal section 116A is placed in a different chamber of heart 102 than distal section 110A. Blood vessel 120 may include, but is not limited to, a superior vena cava (SVC), an inferior vena cava (IVC), left pulmonary artery, or a coronary sinus of the patient.

[0035] Proximal section 116A may be a rigid body, e.g., may define a rigid housing. The housing of proximal section 116A may define similar or dimensions than the housing of distal section 110A. In some examples, as illustrated in FIG. 1 A, proximal section 116Aincludes one rigid body. In some examples, proximal section 116A includes two or more rigid bodies, e.g., connected by intermediate flexible portions. The two or more rigid bodies may extend along a curvature, e.g., such that proximal section 116A defines an overall curved configuration. In such examples, the curvature of proximal section 116A may facilitate disposal of device 104A around curvatures in the vasculature.

[0036] At least some components of device 104A may be disposed within the rigid body of proximal section 116A. For example, one or more power sources of device 104 A may be disposed within proximal section 116A. Proximal section 116A may include one or more electrodes and / or defibrillation electrodes (e.g., shock coil(s), an electrically active surface of proximal section 116A) disposed on, distal to, or proximal to Proximal section 116A (e.g., on medial section 114 but close to Proximal section 116A, on an extension extending proximally from a proximal end of proximal section 116A). Proximal section 116A may be configured to deliver cardiac pacing signals to cardiac tissue of heart 102 and / or to wall tissue of blood vessel 120 at or proximal section 116A, e.g., via electrode(s) on proximal section 116A.

[0037] Proximal section 116A may include one or more fixation elements disposed on, along, proximal to, and / or distal to a housing of proximal section 116A. The one or more fixation elements may engage with wall tissue of heart 102 and / or blood vessel 120 to maintain a position of proximal section 116A within a chamber of heart 102 and / or blood vessel 120. The one or more fixation elements may engage with tissue of the patient with or without penetrating the tissue. The one or more fixation elements may include, but are not limited to, fixation tine(s), fixation barb(s), fixation heli(ces), expandable stent(s), inflatable elements, or the like. In some examples, electrode(s) of proximal section 116A are disposed on the one or more fixation elements.

[0038] In some examples, proximal section 116A is a proximal-most portion of device 104 A. In some examples, device 104 A includes one or more extensions extending proximally from a proximal end of proximal section 116A. The one or more extensions may include, but are not limited to, electrode(s), leadlet(s), one or more flexible sections, one or more rigid sections, or the like. The one or more extensions may extend further into the vasculature and away from heart 102.

[0039] In some examples, device 104 A includes a first set of one or more power sources in distal section 110A and a second set of one or more power sources in proximalsection 116A. In such examples, each set of power source(s) may provide power to components of device 104A to perform different functions. For example, the first set of power source(s) in distal section 110A may provide power to components of device 104A within distal section 110A, e.g., for sensing and / or delivery of electrical signals at or around target location 106. In some examples, the first and second sets of power source(s) may provide power to the components within the respective distal and proximal sections 110A, 116A, e.g., to transmit a defibrillation signal between distal and proximal sections 110A, 116A and into the tissue of heart 102. One or more sets of power source(s) may include rechargeable power source(s). In some examples, the configuration of device 104A may define a charging loop for the rechargeable power source(s).

[0040] Medial section 114 may connect distal and proximal sections, 110A, 116A. At least a portion of medial section 114 may be flexible, e.g., to allow for flexure of device 104 in response to movement of heart 102 throughout a cardiac cycle. In some examples, as illustrated in FIG. 1 A, an entire length of medial section 114 from distal section 110A to proximal section 116A is flexible. In some examples, medial section 114 may include one or more rigid bodies. In such examples, rigid body may be connected at either end to an adjacent rigid body (e.g., another rigid body on medial section 114, to distal section 110A, to proximal section 116A) via a flexible section.

[0041] Medial section 114 may define one or more inner lumen connecting an inner volume of distal section 110A to an inner volume of proximal section 116A. The components of device 104A within the inner volumes of distal and proximal sections 110A, 116A, may be electrically connected via electrical conductor(s) extending through the inner lumen of medial section 114. In some examples medial section 114 includes a support element disposed within and extending through the inner lumen of medial section 114. The support element may control an amount of flexure of medial section 114 and / or inhibit excessive flexure of medial section 114. Electrode(s) and / or sensor(s) may be disposed on or within medial section 114. In some examples, as illustrated in FIG. 1 A, where an intermediate chamber of heart 102 (e.g., RA of heart 102) separates distal section 110A and proximal section 116A. the electrode(s) and / or sensor(s) of medial section 114 may be disposed within the intermediate chamber.

[0042] The electrode(s) and / or sensor(s) on one or more of distal section 110A, medial section 114, or proximal section 116A may sense signals from the patient and transmit thesignals to processing circuitry of device 104A (e.g., disposed within distal section 110A and / or proximal section 116A). The processing circuitry may determine whether to deliver a therapy signal to heart 102 and / or a type of therapy signal to deliver to heart 102 based at last in part on the sensed signals from the electrode(s) and / or sensor(s) on or within distal section 110A, medial section 114, and / or proximal section 116A.

[0043] In some examples, sensor(s) on medial section 114 may sense electrical activity within a chamber of heart 102 (e.g., atrial electrical activity of heart 102). The processing circuitry of device 104 A may determine, based on the sensed electrical activity, an electrogram (EGM) of the chamber of heart 102 (e.g., an atrial EGM). The processing circuitry may perform supraventricular tachycardiac (SVT) discrimination (e.g., dualchamber sensing) based at least in part on the determined EGM. In some examples, sensor(s) 114 sense mechanical or acoustic signals from heart 102. The processing circuitry may supplement the determined EGMs with the sensed mechanical and / or acoustic signals to monitor electrical stability of one or more chambers of heart 102 and / or hemodynamic status of heart 102.

[0044] The processing circuitry of device 104 A may cause signal generation circuitry of device 104A to transmit a defibrillation shock signal (e.g., a defibrillation shock pulse) between the defibrillation electrodes on distal and proximal sections 110A, 116A. The defibrillation shock signal may travel from a first defibrillation electrode at or around distal section 110A to a second defibrillation electrode at or around proximal section 116A, or vice versa. The defibrillation shock signal may travel through cardiac tissue of heart 10 between the first and second defibrillation electrodes, thereby shocking the cardiac tissue.

[0045] FIG. IB is a conceptual diagram illustrating another example device 104B implanted in heart 102 of the patient. Device 104B may be the same as device 104 A, aside from the elements described below. Device 104B may include distal section HOB, proximal section 116B, and medial section 114 connecting distal section HOB to proximal section 116B. Distal section 110B may be implanted within the RV of heart 102 at or around target location 106B. Target location 106B may be at or around an apex of the RV.

[0046] Distal section 110B of device 104B may define a first shock coil 111. Shock coil 111 may be disposed around an outer surface of distal section 110B (e.g., around at least a portion of an outer surface of a housing of distal section 110B). Distal section 110Bmay define an elongated body extending from a distal end of the housing of distal section HOB. The elongated body may penetrate wall tissue of heart 102 at target location 106B. The elongated body may define electrode 112B at or around a distal end of the elongated body. In some examples, as illustrated in FIG. IB, the elongated body defines a helical shape.

[0047] Proximal section 116B may define a second shock coil 118. Second shock coil 118 may be disposed around an outer surface of proximal section 116B (e.g., around at least a portion of an outer surface of a housing of proximal section 116B). When proximal section 116B is disposed within blood vessel 120, an outer surface of second shock coil 118 may be in contact with a vessel wall of blood vessel 120.

[0048] Shock coils 111 and 118 may define a shock vector. Device 104B may transmit a defibrillation shock signal along the shock vector. Shock coils 111 and 118 may be separated along device 104B by a greater distance, compared to other implantable cardioverter defibrillators (ICDs) and / or may be placed closer to cardiac tissue of heart 102 than other ICDs. The increased distance between shock coils 111, 118 and / or the placement of shock coils 111, 118 near cardiac tissue may allow for the user of a lower-amplitude defibrillation shock signal transmitted between shock coils 111 and 118 to successfully return heart 102 to a regular cardiac cycle. In some examples, a first set of power source(s) in distal section HOB powers first shock coil 111 and a second set of power source(s) in proximal section 116B powers second shock coil 118. Powering both shock soils 111, 118 during transmission of the defibrillation shock signal may reduce the effect of a direct current (DC) bias between distal and proximal sections 110B, 116B on the efficacy of the defibrillation shock signal. In some examples, device 104B may include other defibrillation electrodes in addition to and / or instead of shock coils 111 and 118.

[0049] FIG. 1C is a conceptual diagram illustrating another example device implanted in the heart of the patient. Device 104C may be the same as device 104 A, aside from the elements described below. Device 104C may include distal section HOC, proximal section 116C, and medial section 114 connecting distal section 110C to proximal section 116C. Distal section 110C may be implanted within the RA of heart 102 at or around target location 106C. Target location 106C may be at or around a Triangle of Koch of heart 102. Proximal section 116C may be implanted within the RV of heart 102 at or around targetlocation 122. Target location 122 may be at or around an apex of the RV or at another location within heart 102 (e.g., within the RV).

[0050] Distal section 110C may define one or more electrodes on or around a distal end of a housing of distal section 110C. The one or more electrodes may include distal electrode 112C. Device 104C may deliver a cardiac pacing signal to one or more chambers of heart 102 (e.g., to RA and / or LV of heart 102) to capture one or more chambers of heart 102.

[0051] Proximal section 116C may be affixed to wall tissue of heart 102 at or around target location 122 via one or more fixation elements (e.g., fixation tines, fixation barbs, fixation helix) at or around an end of proximal section 116C. When distal section 110C is implanted at target location 106, and proximal section 110C is implanted at target location 122, defibrillation electrodes on distal and proximal sections HOC, 116C (e.g., shock coils 111, 118 respectively) may define a shock vector extending around heart 102 and / or through septum 108. In some examples, distal section HOC may deliver therapy signals (e.g., pacing and / or defibrillation signals) to one chamber of heart 102 (e.g., to RA) and proximal section 116C may deliver therapy signals (e.g., pacing and / or defibrillation signals) to another chamber of heart 102 (e.g., to RV).

[0052] While FIGS. 1 A - 1C illustrate devices 104A-C with different features, other example devices 104 described herein may include features from any of devices 104A-C, or other devices 104 described herein (e.g., device 104D as illustrated in FIG. 2D below) in any combination. For example, device 104A may include any of distal sections 110A-C, any of proximal sections 116A-C, distal section 110 with one or more elements of any of distal sections 110A-C, and / or proximal section 116 with one or more elements of any of proximal sections 116A-C. While FIGS. 1A-1C illustrate devices 104A-C being entirely disposed within the vasculature of the patient, at least a portion of an example device 104 (e.g., including any of devices 104A-C) may be disposed within an epicardial region around heart 102 of the patient. In such examples, the at least the portion of device 104 may deliver therapy signals (e.g., pacing and / or defibrillation signals) to the epicardium of heart 102 (e.g., from within the pericardium and outside the epicardium).

[0053] In some examples, proximal section 116 of device 104 is placed within the left pulmonary artery of the patient. Placement of proximal section 116 within the left pulmonary artery may allow device 104 to define a defibrillation threshold with animproved Defibrillation Threshold (DFT), e.g., compared to one or more other configurations described herein (e.g., as illustrated in FIGS. 1 A-C). Placement of proximal section 116 within the left pulmonary artery may also reduce strain on the tricuspid value of the patient and / or reduce tricuspid valve regurgitation. Placement of proximal section 116 within the left pulmonary artery may also improve fixation of device 104 within the vasculature and / or inhibit unintended movement of device 104 within the vasculature.

[0054] The device described herein (e.g., any of devices 104) may sense signals from and / or deliver therapy signals to cardiac tissue of heart 102). For example, device 104A-C may deliver cardiac pacing signals and / or defibrillation signals to one or more regions within heart 102. Cardiac pacing therapy delivered by cardiac pacing signals may include, but is not limited to, antitachycardia pacing (ATP), single-chamber pacing, multi-chamber synchronous pacing, backup cardiac pacing, or permanent cardiac pacing. In some examples, device 104 may be cardiac resynchronization therapy with a defibrillator (CRT-D) device. Device 104 being capable of delivering both cardiac pacing signals and defibrillation signals depending on the need of the patient may reduce an amount of unnecessary defibrillation shocks delivered to the patient, which may increase the lifespan of device 104 and / or reduce patient discomfort.

[0055] FIG. 2A is a perspective diagram illustrating a side view of example device 104 A of FIG. 1 A. Device 104 A may define an elongated body extending along longitudinal axis 201 from a distal end 204A to a proximal end 204B. The elongated body may include distal section 110A, medial section 114, and proximal section 116A. Distal section 110A may define distal end 204A and proximal section 116A may define proximal end 204B.

[0056] Distal section 110A, medial section 114, and proximal section 116A may define same, similar, or different dimensions. For example, distal section 110A may define a greater or same diameter as proximal section 116A. Proximal section 116A may define a same or greater length along longitudinal axis 201 as distal section 110A. Medial section 114 may define a length longer than one or more of distal section 110A or proximal section 116A.

[0057] Distal section 110A may define a housing 202, distal electrode 112A, tine(s) 206, reference electrode 208, and defibrillation electrode 111. In some examples, distalsection 110A does not include defibrillation electrode 111 and at least a portion of an electrically active outer surface of housing 202 may perform the functions attributed to defibrillation electrode 111 as described herein.

[0058] Housing 202 may define a rigid body. Housing 202 may define a hermetically sealed cavity configured to contain at least some electronic components of device 104 A. Housing 202 may be formed from a conductive material including titanium or titanium alloy, stainless steel, MP35N (a non-magnetic nickel-cobalt-chromium-molybdenum alloy), platinum alloy or other bio-compatible metal or metal alloy, or other suitable conductive material. In some examples, housing 202 is formed from a non-conductive material including ceramic, glass, sapphire, silicone, polyurethane, epoxy, acetyl copolymer plastics, polyether ether ketone (PEEK), a liquid crystal polymer, other biocompatible polymer, or other suitable non-conductive material.

[0059] Housing 202 may extend distally from one end of medial section 114 to distal end 204A. Housing 202 may be cylindrical or substantially cylindrical, but may be other shapes, e.g., prismatic or other geometric shapes. An end of housing 202 at or around distal end 204A may define a flat surface (e.g., orthogonal to longitudinal axis 201), a domed surface, an angled surface, or any other shaped surfaces. Distal electrode 112A and tine(s) 206 may be disposed on housing 202 at or around distal end 204A and may extend distally from distal end 204 A.

[0060] Tine(s) 206 may be formed from a shape memory material including, but not limited to, Nitinol. Tine(s) 206 may transition between a constrained configuration and an unconstrained configuration (e.g., as illustrated in FIG. 2A). In the unconstrained configuration, tine(s) 206 may extend radially away from longitudinal axis 201 and curve back towards proximal end 204B. Each of tine(s) 206 may terminate in a distal tip configured to penetrate tissue of the patient. When tine(s) 206 are unconstrained, tine(s) 206 may transition from the constrained configuration to the unconstrained configuration. During the transition, tine(s) 206 may penetrate cardiac tissue of heart 102 (e.g., at or around target location 106A) and affix distal section 110A to the cardiac tissue. Distal section 110A may include one or more fixation features on housing 202 at or around distal end 204A to affix distal section 110A to the cardiac tissue. The one or more fixation features may include, but is not limited to, prongs, barbs, surface textures, recesses, protrusions, or the like.

[0061] When distal section 110A is affixed to the cardiac tissue, distal electrode 112A may be placed in contact with a surface of the cardiac tissue. Distal electrode 112A may be a button electrode, a spring electrode, or the like. Distal electrode 112A may define an electrically active region and may be configured to transmit electrical signals (e.g., cardiac pacing signal) to and / or receive electrical signals from the cardiac tissue in contact with distal electrode 112A via the electrically active region. Distal electrode 112A may be formed from an electrically conductive material, such as titanium, platinum, iridium, tantalum, stainless steel, or alloys thereof. For example, distal electrode 112A may be formed from one or more of Platinum Iridium, a Platinum Iridium-clad alloy (e.g., Platinum Iridium-clad Titanium orNitinol), Nitinol, or Tantalum Tungsten. In some examples, at least a portion of distal electrode 112A may be coated within an electrically insulating coating, e.g., a parylene, polyurethane, silicone, epoxy, or other insulating coating, to limit an electrically conductive active surface area of distal electrode 112A and define the electrically active region.

[0062] All, substantially all, or a portion of housing 202 may function as electrode 208 and / or first shock coil 111. Electrode 208 may function as an anode electrode during pacing and / or sensing, e.g., while distal electrode 112A functions as the cathode electrode. Electrode 208 and / or shock coil can fully or partially circumscribe housing 202, e.g., at or around a proximal end of housing 202. The proximal end of housing 202 may be connected to medial section 114. FIG. 2A shows electrode 208 extending as a singular band around the outer perimeter of housing 202. Electrode 208 can also include multiple segments spaced a distance apart along longitudinal axis 201 and / or around a perimeter of housing 202.

[0063] When housing 202 is formed from a conductive material, portions of housing 202 may be electrically insulated by a non-conductive material such as a coating of parylene, polyurethane, silicone, epoxy or other biocompatible polymer, or other suitable material. For the portions of housing 202 without the non-conductive material, one or more discrete areas of housing 202 with conductive material can be exposed to define electrode 208 and / or first shock coil 111.

[0064] First shock coil 111 may be disposed around an outer surface of housing 202 and / or medial section 114. First shock coil 111 may define an electrically active surface and may transmit a defibrillation shock signal from the electrically active surface. In someexamples, one or more portions of first shock coil 111 may be coated with a non-conductive material, e.g., to define an area of the electrically active surface. In some examples, instead of first shock coil 111 on distal section 110A and / or medial section 114, an electrically active surface of the outer surface of housing 202 may perform the functionality of first shock coil 111 (e.g., may transmit a defibrillation shock signal).

[0065] Proximal section 116A may extend proximally along longitudinal axis to proximal end 204B. Proximal section 116A may define a housing 210 extending from a proximal end of proximal section 116A to proximal end 204B. Proximal section 116A may include second shock coil 118, tine(s) 224, and a delivery tool interface member 212 extending proximally from proximal end 204B.

[0066] Housing 210 may define a rigid body. Housing 210 may define a hermetically sealed cavity configured to contain at least some electronic components of device 104 A. Together, housings 202, 210 and medial section 114 may contain all of the electronic components of device 104 A. Housing 210 may be formed from a conductive material including titanium or titanium alloy, stainless steel, MP35N (a non-magnetic nickel -cobalt-chromium-molybdenum alloy), platinum alloy or other bio-compatible metal or metal alloy, or other suitable conductive material. In some examples, housing 210 is formed from a non-conductive material including ceramic, glass, sapphire, silicone, polyurethane, epoxy, acetyl co-polymer plastics, polyether ether ketone (PEEK), a liquid crystal polymer, other biocompatible polymer, or other suitable non-conductive material. Housing 210 may extend proximally from a proximal end of medial section 114 to proximal end 204B. Housing 210 may be cylindrical or substantially cylindrical, but may be other shapes, e.g., prismatic or other geometric shapes. Housing 210 may define same, similar, or different dimensions than housing 202.

[0067] Proximal section 116A may include second shock coil 118 disposed over an outer surface of housing 210. In some examples, as illustrated in FIG. 2A, second shock coil 118 may be disposed over the outer surface of housing 210 at or around the proximal end of medial section 114 and / or over a portion of medial section 114. Second shock coil 118 may include the same features as shock coil 111 and may form an electrical circuit with shock coil 111 for transmission of the defibrillation shock signal between shock coils 111, 118. Shock coils 111, 118 may define a defibrillation shock vector extending from first shock coil 111 to second shock coil 118. In some examples, where housing 210 isformed from an electrically conductive material, an electrically active surface of housing 210 may perform the functions of second shock coil 118 instead of or in addition to second shock coil 118.

[0068] Tine(s) 224 may be disposed on housing 202 and may be configured to transition from a constrained configuration and an unconstrained configuration. In the constrained configuration (e.g., when tine(s) 224 are constrained by a guide element), tine(s) 224 may be collapsed against the outer surface of housing 210, e.g., to reduce an overall profile of proximal section 116A. When unconstrained, tine(s) 224 may expand radially away from housing 202 to the unconstrained configuration and secure proximal section 116A within blood vessel 120. Tine(s) 224 may be configured to penetrate a vessel wall of blood vessel 120 to secure proximal section 116A within blood vessel 120. In some examples, tine(s) 224 act against the vessel wall of blood vessel 120 without penetrating the vessel wall to secure proximal section 116A within blood vessel 120. Tine(s) 224 may be formed from a shape memory material including, but is not limited to, Nitinol.

[0069] Tine(s) 224 may define electrically active surfaces and may transmit and / or sense electrical signals from the wall tissue of blood vessel 120. Tine(s) 224 may be positioned on housing 210 and proximal to second shock coil 118 (e.g., as illustrated in FIG. 2A) and / or distal to second shock coil 118. In some examples, instead of or in addition to tine(s) 224, proximal section 116A may include one or more additional fixation features including, but are not limited to, fixation barbs, expandable fixation elements, fixation helices (e.g., a side helix extending around an outer surface of housing 210), or the like.

[0070] Delivery tool interface member 212 may engage with a delivery tool (e.g., a tether assembly) operated by the clinician. The clinician may navigate device 104 A within the vasculature of the patient by applying forces (e.g., pushing, pulling, rotary forces) on delivery tool interface member 212 via the delivery tool. Delivery tool interface member 212 may be electrically conductive and may transmit electrical signals (e.g., from electrical components of device 104 A) along the delivery tool to an external computing device operated by the clinician. Delivery tool interface member 212 may be configured to deflect away from longitudinal axis 201, e.g., to allow for the positioning of at least adistal portion of delivery tool next to device 104A (e.g., during the positioning of proximal section 116A).

[0071] Medial section 114 may connect distal section 110A to proximal section 116A. Medial section 114 may be flexible and may be configured to flex away from longitudinal axis 201. An inner lumen of medial section 114 may connect an inner volume of housing 202 to an inner volume of housing 210. Medial section 114 may include one or more rigid bodies (not pictured in FIG. 2A) disposed along the length of medial section 114. In some examples, medial section 114 includes one or more electrodes 225 disposed around an outer surface of medial section 114. Electrode(s) 225 may sense electrical signals, e.g., within a chamber (e.g., atrium) of heart 102 between target location 106 A and blood vessel 120.

[0072] Medial section 114 may include one or more conductors disposed within the inner lumen and electrically connecting the components disposed within housing 202 and housing 210. The one or more conductors may be configured to flex with medial section 114 and assume a plurality of different shapes. The one or more conductors may include, but are not limited to, a metallic alloy (e.g., a Tantalum alloy) capacitor, a polymer capacitor, or a diamond capacitor (a chemical vapor deposition (CVD) diamond).

[0073] In some examples, one or more of distal section 110A, medial section 114, or proximal section 116A may define one or more power-generation elements. The one or more power-generation elements may include self-powering elements, energy harvesting systems, or the like. In some examples, the one or more power-generation elements include a fl exoelectric material and may generate electrical power for device 104 A based on flexure of the fl exoelectric material, e.g., as a result of movement of heart 102 during a cardiac cycle. The electrical power generated by the one or more power-generation elements may at least supply electrical power to device 104 A, e.g., for the sensing of signals from heart 102, for delivery of therapy signals (e.g., pacing signals, defibrillation shock signals to heart 102. The electrical power generated by the one or more powergeneration elements may increase an overall lifespan of device 104 A. In some examples, when device 104A is deployed within the vasculature of the patient, device 104A may define a charging loop to recharge the one or more power-generation elements. In such examples, device 104A may recharge the one or more power-generation coils via a charging coil placed on or within the body of the patient and oriented to device 104 A.

[0074] FIG. 2B is a perspective diagram illustrating a side view of example device 104B of FIG. IB. Device 104B may be substantially similar to device 104A illustrated in FIG. 2A and described above, aside from the elements described below.

[0075] Distal section 112B may include one or more electrodes (e.g., including distal electrode 112B) extending distally from face 220 of housing 202 of distal section HOB. Distal electrode 112B may be disposed on an elongated body defining a helical shape. Distal electrode 112B may be configured to penetrate into cardiac tissue at or around target location 112B and deliver therapy signals (e.g., cardiac pacing signals) from within the cardiac tissue. The elongated body may interface with the cardiac tissue to affix distal section 112B to the cardiac tissue. In some examples, distal section 112B includes one or more fixation features on face 220. The one or more fixation features may include, but are not limited to, tines, barbs, surface textures, ramps, protrusions, recesses, or the like.

[0076] In some examples, as illustrated in FIG. 2B, housing 202 and housing 210 may define different diameters. For example, as illustrated in FIG. 2B, housing 202 of distal section HOB may define a greater diameter than housing 210 of proximal section 116B. In such examples, medial section 114 may define a tapered profile from housing 202 to housing 210. As illustrated in FIG. 2B, medial section 114 may taper proximally from a first diameter of housing 202 to a second diameter of housing 210. Tapering medial section 114 may increase a volume within an inner lumen of medial section 114 while allowing at least a portion of medial section 114 (e.g., a proximal portion of medial section 114 connected to proximal section 116B) to be disposed within a narrower portion of the vasculature of the patient (e.g., within blood vessel 120 compared to a chamber of heart 102). The increased volume within the inner lumen of medial section 114 may allow more and / or larger components to be disposed within medial section 114. For example, the increased volume within the inner lumen of medial section 114 may allow for the placement of additional electrodes and / or sensors within medial section 114.

[0077] FIG. 2C is a perspective diagram illustrating a side view of example device 104C of FIG. 1C. Device 104C may be substantially similar to devices 104A, 104B illustrated in FIGS. 2A and 2B and described above, aside from the elements described below.

[0078] In some examples, proximal section 116C of device 104C is implanted within one chamber of heart 102 (e.g., at or around target location 122) and distal section 110C ofdevice 104C is implanted within another chamber of heart 102 (e.g., at or around target location 106C). Distal section HOC of device 104C may include distal electrode 112C. Distal electrode 112C may define a helical shape and may penetrate cardiac tissue at or around target location 106C to affix distal section 1 IOC to the cardiac tissue.

[0079] Proximal section 116C may include tine(s) 225 and electrode 227 disposed on housing 210 and at or around proximal end 204B. Tine(s) 225 may be substantially similar to tine(s) 206 of device 104 A. Tine(s) 225 may transition between a constrained configuration and an unconstrained configuration and may penetrate cardiac tissue at or around target location 122 to affix proximal section 116C to the cardiac tissue. Electrode 227 may be disposed on a surface of housing 210 defining proximal end 204B and may extend proximal of proximal end 204B. Electrode 227 may include, but is not limited to, a helical electrode, a button electrode, a spring electrode, or the like.

[0080] When proximal section 116C is affixed to the cardiac tissue, electrode 227 may be placed into contact with the cardiac tissue, e.g., with or without penetrating the cardiac tissue. Electrode 227 may sense signals from and / or deliver therapy signals (e.g., cardiac pacing signals, defibrillation signals) to target location 122. Device 104C may transmit a defibrillation shock signal between target locations 106C and 122 (e.g., via shock coils 111 and 118, respectively) to defibrillate heart 102. Device 104C may deliver cardiac pacing signals to target locations 106C and 122 via distal electrode 112C and electrode 227, respectively to pace two or more chambers of heart 102, e.g., synchronously.

[0081] FIG. 2D is a perspective diagram illustrating another example of the device of FIGS. 1 A-1C. Device 104D may be substantially similar to devices 104A-C illustrated in FIGS. 2A-2C and described above, aside from the elements described below.

[0082] Proximal section 116D may include an expandable structure 226 around housing 210. Expandable structure 226 may include, but is not limited to, an expandable coil, an expandable stent, an expandable basket, a ballon or other inflatable element, or the like. Expandable structure 226 may be configured to transition between a collapsed configuration (e.g., as illustrated in FIG. 2D) and an expanded configuration. Expandable structure 226 may include a plurality of electrodes 228 arranged on an outer surface of expandable structure 226. In the expanded configuration, expandable structure 226 may expand and place electrodes 228 in contact with a surface of a chamber of heart 102 and / or a vessel wall of blood vessel 120, e.g., without penetrating the surface of the cardiac tissueand / or the vessel wall. Electrodes 228 may deliver cardiac pacing signals or defibrillation shock signals through the surface of the chamber of heart 102 and / or the vessel wall and into cardiac tissue of heart 102. When expanded, expandable structure 226 may interface with the surface of the chamber and / or with the vessel wall to maintain a position of proximal section 116 within the chamber of heart 102 and / or blood vessel 120.Expandable structure 226 may define openings separated by struts and / or extensions and body fluid (e.g., blood) may flow through the openings, e.g., such that expandable structure 226 does not occlude portions of the vasculature of the patient when expandable structure 226 is in the expanded configuration.

[0083] FIG. 3A is a perspective diagram illustrating an example delivery system 302 for device 104 (e.g., any of devices 104A-D) of FIGS. 1A-2D. While delivery system 302 is primarily illustrated and described for delivery of device 104A, delivery system 302 may be used for delivery of any device described herein. FIG. 3B is a perspective diagram illustrating delivery system 302 of FIG. 3A after implantation of distal section 110A of device 104 A.

[0084] Delivery system 302 may include a delivery catheter 304, guide element 310, and tether assembly 314. Delivery catheter 304 may include an elongated body extending along longitudinal axis 201 and defining an inner lumen 312. Delivery catheter 304 may define a delivery cup 306 at or around a distal end of delivery catheter 304. Delivery cup 306 may define an opening 308 at a distal end of delivery cup 306.

[0085] Device 104A may be retained within inner lumen 312 of delivery catheter 304. At least a portion of device 104A (e.g., distal section 110A) may be retained within delivery cup 306. Delivery cup 306 may have a sufficient length to retain distal section 110A of device 104A and any other elements extending distal of distal section 110A. For example, as illustrated in FIG. 3A, delivery catheter 304 may retain tine(s) 206 extending distally from distal section 110A in a constrained configuration.

[0086] A remaining portion of device 104 A may be disposed within inner lumen 312 of delivery catheter 304 and proximal to delivery cup 306. Within inner lumen 312, guide element 310 may be disposed over at least a portion of device 104A (e.g., over proximal section 116A of device 104A). Guide element 310 may include, but is not limited to, a guide sheath. Guide element 310 may be configured to be advanced and / or retracted along longitudinal axis 201 within delivery catheter 304. Guide element 310 may retain fixationfeatures on device 104A (e.g., fixation tine(s) 224) in a constrained configuration. Guide element 310 may be retracted along longitudinal axis 201 relative to device 104A to unconstrain the fixation features and allow the fixation features to transition from the constrained configuration to the unconstrained configuration.

[0087] A distal portion of tether assembly 314 may be disposed within an inner lumen of guide element 310 (e.g., as illustrated in FIG. 3B). Tether assembly 314 may define a tether head assembly 316 at or around a distal end of tether assembly 314. Tether head assembly 316 may be removably coupled to delivery tool interface member 212 on proximal section 116A and define interface 318 between tether assembly 314 and device 104A. When tether head assembly 316 is coupled to delivery tool interface member 212, tether assembly 314 may transmit forces from the clinician to device 104A (e.g., a pushing force, a pulling force, a rotary force), e.g., to manipulate device 104A within the body of patient.

[0088] During implantation of device 104A, the clinician may retain distal section 110A in delivery cup 306 as the clinician navigates delivery cup 306 within the vasculature of the patient, e.g., to inhibit unintended penetration of a blood vessel wall of the vasculature during navigation of delivery system 302, e.g., as illustrated in FIG. 3B. When the clinician determines that delivery cup 306 is at or around a target implantation location for distal section 110A (e.g., any of target locations 112-C), the clinician may at least partially advance distal section 110A out of opening 308 of delivery cup 306 towards the tissue at or around the target implantation location. The clinician may advance distal section 110A out of opening 308 by advancing, via tether assembly 314, device 104 A within inner lumen 312 of deliver catheter 304. The clinician may advance guide element 310 alongside device 104A. Fixation elements on distal section 110A (e.g., fixation tine(s) 206) may engage with the tissue and affix distal section 110A to the tissue.

[0089] The clinician may sense signals from heart 102 via distal section 110A (e.g., via distal electrode 112A) to determine whether distal section 110A is implanted at a proper position within heart 102. The clinician may readjust the position of distal section 110A until the clinician determines that distal section 110A is in a proper position within heart 102, e.g., for efficacious delivery of cardiac pacing signals and / or defibrillation signals to heart 102 and / or for accurate sensing of signals from heart 102.

[0090] Once distal section 110A is implanted, the clinician may advance proximal section 116A to the corresponding target location (e.g., within blood vessel 120, at target location 122 within heart 102) via tether assembly 314. The clinician may advance all of device 104A and at least a portion of tether assembly 314 (e.g., at least tether head assembly 316) out of guide element 310. Delivery tool interface member 212 may bend relative to longitudinal axis 201 and tether head assembly 316 and at least a portion of tether assembly 314 may be placed next to device 104A (e.g., along a reference axis substantially parallel to longitudinal axis 201). In such a configuration, the clinician may advance proximal section 116A in a direction away from distal section 110A to place proximal section 116A at the target location. The configuration may reduce an overall profile of delivery system 302 within the body of the patient and may allow for navigation of tether assembly 314 and proximal section 116A in the constrained spaces within blood vessels. Medial section 114 may be flexible and may facilitate movement of proximal section 116A, e.g., without causing distal section 110A to detach from the tissue. Delivery system 302 may define one or more curvatures, e.g., to allow for navigation of proximal section 116A within the vasculature. In some examples, as illustrated in FIG. 3B, guide element 310 may define each curvature and tether assembly 314 may be advanced within guide element 310 and around each curvature.

[0091] In some examples, delivery tool interface member 212 may be disposed distal of a proximal end of proximal section 116 (e.g., on medial section 114). In such examples, the clinician may insert and / or affix device 104 to target location 106 without gripping onto proximal section 116 via tether assembly 314. For example, the clinician may retract tether assembly 314 into deliver catheter 304 while tether assembly 314 is still attached to delivery tool interface member 212. In such examples, at least a portion of proximal section 116 and / or medial section 114 may be retracted (e.g., looped) back into delivery cup 306 of delivery catheter 304. In some examples, when at least a portion of device 104 is retracted back into delivery cup 306, both distal section 110 and proximal section 116 are external to and distal to deliver cup 306, while at least a portion of medial section 114 is retained within delivery cup 306.

[0092] FIG. 4 is a conceptual diagram illustrating implantation of device 104 of any of FIGS. 1A-2D via example delivery system 302 of FIGS. 3A-3B. FIG. 4 illustrates delivery system 302 and device 104A in the example configuration illustrated in FIG. 3A.While delivery system 302 as illustrated in FIG. 4 is primarily described with regard to implantation of device 104 A, delivery system 302 may be used to implant any device 104 described herein in heart 102.

[0093] The clinician may advance delivery cup 306 of delivery catheter 304 into a chamber of heart 102 containing target location 106A (e.g., RV of heart 102, as illustrated in FIG. 4). Once opening 308 of distal cup 306 is at or around distal location 106A, the clinician may advance at least a portion of distal section 110A out of distal cup 306 and affix fixation elements on distal section 110A (e.g., tine(s) 206) to tissue of heart 102 (e.g., septum 108) at or around target location 106A. For example, when tine(s) 206 are advanced to outside of delivery cup 306, tine(s) 206 may transition from a constrained configuration to an unconstrained configuration and penetrate tissue of heart 102 at or around target location 106A to affix distal section 110A to the tissue. When distal section 110A is affixed to the tissue, distal electrode 112A may be placed in contact with cardiac tissue of heart 102 at or around target location 106A. The clinician may re-position device 104A at different target locations 106 within heart 102 until the clinician determines (e.g., based on sensed signals from distal electrode 106A and / or other electrodes on or within distal section 110A) that distal section 110A is implanted at a suitable location for efficacious delivery of therapy signals (e.g., cardiac pacing signals) to cardiac tissue of heart 102, e.g., via distal electrode 112A.

[0094] When distal section 110A is implanted, the clinician may retract delivery catheter 304 and guide element 310 (not pictured in FIG. 4) proximally relative to device 104 A until the entire elongated body of device 104 A, delivery tool interface member 212, at least a distal portion of tether assembly 314, and interface 318 between tether assembly 314 and device 104A are external to delivery catheter 304. Delivery tool interface member 212 may be bent or extend away from longitudinal axis 201 of device 104A, e.g., to allow placement of the distal portion of tether assembly 314 parallel to at least proximal section 116A of device 104 A.

[0095] The clinician may, using tether assembly 314, orient the proximal end of device 104A towards blood vessel 120. For example, the clinician, may transmit, via tether assembly 314, forces to proximal section 116A of device 104 A to orient interface 318 towards blood vessel 120. The clinician may than apply forces on tether assembly 314 (e.g., using a handle of tether assembly 314) to cause the tether head assembly 316 andproximal portion 116A to enter blood vessel 120, e.g., in direction 402. Direction 402 may extend away from distal section 110A. Within blood vessel 120, the clinician may position proximal portion 116A at a location where the clinician determines (e.g., based on sensed signals from electrode(s) and / or sensor(s) in or on device 104A) where device 104A may deliver efficacious therapy signals (e.g., defibrillation signals) to cardiac tissue of heart 102 via shock coils 111, 118 on distal section 110A and proximal section 116A, respectively.

[0096] The clinician may, using tether assembly 314, secure proximal section 116A within blood vessel 120. The clinician may place fixation features on device 104A (e.g., tine(s) 224, tine(s) 225, expandable structure 226, fixation helix) in contact with a vessel wall of blood vessel 120 (e.g., with or without penetrating the vessel wall) to inhibit movement of proximal section 116A within blood vessel 120. Once the clinician determines that proximal section 116A is secured within blood vessel 120, the clinician may actuate tether assembly 314 (e.g., via a handle of tether assembly 314) to detach tether head assembly 316 from delivery tool interface member 212 at interface 318 and retract delivery system 302 from within the body of the patient.

[0097] FIG. 5 is a block diagram illustrating an example configuration of an example device 104 of any of FIGS. 1-4. As illustrated in FIG. 5, device 104 include electrodes 112 and 208 and shock coils 111 and 118, which may be configured as described with respect to FIGS. 1-4. In the example shown in FIG. 5, device 104 includes switch circuitry 502, sensing circuitry 504, signal generation circuitry 506, sensor(s) 508, processing circuitry 510, telemetry circuitry 512, memory 514, and power source 516. The various circuitry may be, or include, programmable or fixed function circuitry configured to perform the functions attributed to respective circuitry. Memory 514 may store computer-readable instructions that, when executed by processing circuitry 510, cause device 104 to perform various functions. Memory 514 may be a storage device or other non-transitory medium. The components of device 104 illustrated in FIG. 5 may be housed within housing 202, housing 210, and / or medial section 114. In some examples, the components of device 104 illustrated in FIG. 5 may be housed in housings 202, 210 and connected along medial section 114 via conductor(s) disposed within medial section 114.

[0098] Signal generation circuitry 506 generates electrical therapy signals, e.g., cardiac pacing signals, defibrillation signals. Switch circuitry 502 is coupled to electrodes112, 208, and to shock coils 111, 118 and may include one or more switch arrays, one or more multiplexers, one or more switches (e.g., a switch matrix or other collection of switches), one or more transistors, or other electrical circuitry. Switch circuitry 502 is configured to direct therapy signals from signal generation circuitry 506 to a selected combination of electrodes 112, 208, and / or coils 111, 118, having selected polarities, e.g., to selectively deliver pacing pulses to the RA, ventricles, or interventricular septum of heart 102 and / or to deliver defibrillation shock signals to heart 102. For example, switch circuitry 502 may couple distal electrode 112, to signal generation circuitry 506 as a cathode, and electrode 208 and / or one or more other electrodes (e.g., electrode 227 to signal generation circuitry 506 as an anode. As another example, in order to deliver defibrillation shock signals to heart 102, switch circuitry 502 may couple first shock coil 111 to signal generation circuitry 506 as a cathode and second shock coil 118 to signal generation circuitry 506 as an anode, or vice versa.

[0099] Switch circuitry 502 may also selectively couple sensing circuitry 504 to selected combinations of electrodes (e.g., distal electrode 112, electrode 208, other electrodes on distal section 110, medial section 114, or proximal section 116), e.g., to selectively sense the electrical activity of one or more chambers of heart 102. Sensing circuitry 504 may include filters, amplifiers, analog-to-digital converters, or other circuitry configured to sense cardiac electrical signals via the selected electrodes. For example, switch circuitry 502 may couple different electrodes to respective sensing channels provided by sensing circuitry 504 to respectively sense either ventricular or atrial cardiac electrical signals. In some examples, sensing circuitry 504 is configured to detect events, e.g., depolarizations, within the cardiac electrical signals, and provide indications thereof to processing circuitry 510. In this manner, processing circuitry 510 may determine the timing of atrial and ventricular depolarizations and control the delivery of cardiac pacing based thereon. Processing circuitry510 may include any one or more of a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), discrete logic circuitry, or any other processing circuitry configured to provide the functions attributed to processing circuitry 510 herein may be embodied as firmware, hardware, software or any combination thereof.

[0100] Sensor(s) 508 may include one or more sensing elements that transduce patient physiological activity to an electrical signal to sense values of a respective patientparameter, e.g., electrical stability of one or more chambers of heart 102 (e.g., ventricular electrical stability of heart 102) and / or a hemodynamic status of the patient. Sensor(s) 508 may include one or more accelerometers, optical sensors, chemical sensors, temperature sensors, pressure sensors, strain gauges, other mechanical sensors, or any other types of sensors. Sensor(s) 508 may output patient parameter values that may be used as feedback to control sensing and delivery of therapy by device 104.

[0101] Telemetry circuitry 512 supports wireless communication between device 104 and an external programmer (not shown in FIG. 5) or another computing device under the control of processing circuitry 510. Processing circuitry 510 of device 104 may receive, as updates to operational parameters from the computing device, and provide collected data, e.g., sensed heart activity or other patient parameters, via telemetry circuitry 512.Telemetry circuitry 512 may accomplish communication by radiofrequency (RF) communication techniques, e.g., via an antenna (not shown).

[0102] Power source(s) 516 delivers operating power to various components of device 104. Power source(s) 516 may include a rechargeable or non-rechargeable battery and a power generation circuit to produce the operating power. Recharging may be accomplished through proximal inductive interaction between an external charger and an inductive charging coil within device 104. In some examples, device 104 includes two or more power sources 516. Each power source 516 may be disposed in one of housing 202 of distal section 110A or housing 210 of proximal section 116A. In such examples, each power source 516 may provide power to different or same components of device 104. For example, one of power sources 516 may provide power to sensing circuitry 504, signal generation circuitry 506 (e.g., for the generation of cardiac pacing signals), to one of shock coils 111 or 118, and / or to sensor(s) 508. Another of power sources 516 may provide power to another of shock coils 111 or 118. Providing power to both shock coils 111 and 118 during delivery of defibrillation shock signals by device 104 may reduce a DC bias between shock coils 111 and 118, thereby reducing a required amplitude of the defibrillation shock signal and increasing an efficacy of the defibrillation shock signal.

[0103] In some examples, device 104 may include one or more power generation components (not pictured in FIG. 5) coupled to power sources 516. The one or more power generation components may be disposed within one or more of distal section 110A, medial section 114, or proximal section 116A. The one or more power generationcomponents may convert forces applied on device 104A (e.g., resulting from mechanical movement of heart 102) to electrical power and may store the generated electrical power within power sources 516.

[0104] In some examples, device 104 is configured to deliver cardiac pacing signal (e.g., via electrodes 112, 208) or to deliver defibrillation shock signals (e.g., via shock coils 111, 118) to heart 102 based on a status (e.g., electrical stability of one or more chambers of heart 102, a hemodynamic status of the patient). Processing circuitry 510 may receive (e.g., from sensing circuitry 504, sensor(s) 508) signals indicating one or more physiological parameters of heart 102 and determine, based on the one or more physiological parameters, one or more of the electrical stability of heart 102 or the hemodynamic status of the patient. The one or more physiological parameters may include, but are not limited to, a respiration rate, a heart rate, changes in an average heart rate, timing of individual waves within a QRS complex of an electrocardiogram signal from heart 102, timing of depolarization of chamber(s) of heart 102, timing of repolarization of chamber(s) of heart 102, a presence of an abnormal heart rhythm, or the like. Based on the one or more physiological parameters, processing circuitry 510 may determine the electrical stability of heart 102 or the hemodynamic status of the patient (e.g., may determine a hemodynamic score for the patient).

[0105] Processing circuitry 510 may compare the status of the patient against a threshold condition (e.g., a threshold score) stored in memory 514. The threshold condition may correspond to a presence of abnormal heart rhythm, a condition where heart 102 is no longer beating and / or one or more other cardiac conditions necessitating the delivery of a defibrillation shock signal. The threshold condition may correspond to one or more of the electrical stability of heart 102 or the hemodynamic status of the patient. Based on a determination that the determined status of the patient satisfies the threshold condition (e.g., that the determined hemodynamic score is greater than or equal to the threshold score), processing circuitry 510 may cause signal generation circuitry 506 to deliver defibrillation shock signals to heart 102. Based on a determination that the determined status of the patient does not satisfy the threshold condition, processing circuitry 510 may cause signal generation circuitry 506 to deliver cardiac pacing signals to heart 102. By switching between the two types of signal delivery based on the needs of the patient, device 104 may have an increased lifespan, reduce overall power consumption,and / or reduce a number of unnecessary shocks delivered to the patient (e.g., thereby reducing patient discomfort).

[0106] FIG. 6 is a flowchart illustrating an example process for delivering defibrillation signals to heart 102 of a patient via an example device 104 of any of FIGS.1-5. While the technique illustrated in FIG. 6 is primarily described with respect to device 104 A, the technique may be performed using any other example device 104 described herein.

[0107] A clinician may advance a distal section 110A of an implantable medical device (IMD) 104A into a chamber of heart 102 of a patient (602). Device 104A may include an elongated body defining distal section 110A, proximal section 116A, and medial section 114 connecting distal section HOAto proximal section 116A. Device 104 A may be coupled to tether assembly 314 via delivery tool interface member 212 disposed on proximal section 116A of device 104A. Device 104A may be disposed within delivery catheter 304 (e.g., within inner lumen 312 of delivery catheter 304). Distal section 110A may be disposed within delivery cup 306 of delivery catheter 304. Delivery cup 306 may constrain fixation elements on distal section 110A (e.g., tine(s) 206) in a constrained configuration and retain fixation elements proximal to opening 308 at a distal end of delivery cup 306.

[0108] The clinician may advance a distal portion of delivery catheter 304 (e.g., including delivery cup 306) from an incision location, through the vasculature of the patient, and into the chamber of heart 102. The chamber may be an atrium or a ventricle (e.g., the RV) of heart 102. Within the chamber, the clinician may position opening 308 of delivery cup 306 at or around target location 106A within the chamber.

[0109] The clinician may affix distal section 110A of IMD 104A to wall tissue of the chamber of heart 102 (604). The clinician may advance distal section 110A out of delivery catheter 304 to affix distal section 110A to the wall tissue, e.g., at or around target location 106A. In some examples, when fixation elements (e.g., tine(s) 206) on distal section 110A are unconstrained by delivery cup 306, the fixation elements expand towards the unconstrained configuration and penetrate the wall tissue, thereby affixing distal section 110A to the wall tissue. In some examples, the clinician causes fixation elements (e.g., a fixation helix) on distal section 110A to penetrate the wall tissue, e.g., by rotating distal section 110A about longitudinal axis 201 using a handle of tether assembly 314.

[0110] When distal section 110A is affixed to the wall tissue, distal electrode 110 on distal section 110A may be placed in contact with a surface of the wall tissue at target location 106A and / or may be disposed within the wall tissue at target location 106A. Device 104A may deliver therapy signals (e.g., cardiac pacing signals) to and / or sense electrical signals from the wall tissue using distal electrode 110.[oni] The clinician may advance proximal section 116A of IMD 104 A into blood vessel 120 connected to heart 102 (606). Blood vessel 120 may include, but is not limited to, a superior vena cava (SVC), an inferior vena cava (IVC), or a coronary sinus of the patient. The clinician may further retract delivery catheter 304 relative to device 104 A to expose medial section 114 and proximal section 116A. The clinician may position tether head assembly 316 of tether assembly 314 alongside proximal section 116 and orient proximal section 116A towards blood vessel 120. The clinician may then advance tether head assembly 316 and proximal section 116A into blood vessel 120, e.g., in direction 402 away from distal section 110A. and position proximal section 116A within blood vessel 120.

[0112] The clinician may secure proximal section 116A of IMD 104 within blood vessel 120 (608). The clinician may place fixation elements on proximal section 116A (e.g., tine(s) 224, a side helix around proximal section 116A) in contact with vessel wall of blood vessel 120. The fixation elements may affix proximal section 116A to the vessel wall, e.g., with or without penetrating the vessel wall. In some examples, the clinician expands an expandable element (e.g., expandable element 226) within blood vessel 120 to secure proximal section 116A within blood vessel 120. In some examples, the clinician may leave proximal section 116A unsecured within blood vessel 120. The clinician may, after placing proximal section 116A within blood vessel 120, detach tether head assembly 316 from delivery tool interface member 212 and retract delivery system 302 including delivery catheter 304 and tether assembly 314 from within the body of the patient. Once detached, the entirety of IMD 104 A may be within the vasculature of the patient.

[0113] IMD 104A may deliver a defibrillation signal to cardiac tissue of heart 102 (610). When IMD 104A is implanted within the patient, first shock coil 111 on or around distal section 110A may be disposed within the chamber of heart 102 and second shock coil 118 on or around proximal section 116A may be disposed within blood vessel 120. Together, shock coils 111 and 118 may define a shock vector for the defibrillation signal.IMD 104A may transmit the defibrillation signal between shock coils 111 and 118 and through any intervening cardiac tissue of heart 102, thereby delivering the defibrillation signal to cardiac tissue, e.g., to shock heart 102 back into a regular cardiac rhythm.

[0114] It 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.

[0115] In one or more examples, the described techniques may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may include non-transitory computer-readable media, which corresponds to a tangible medium such as data storage media (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer).

[0116] In addition, it should be noted that system described herein may not be limited to treatment of a human patient. In alternative examples, the system may be implemented in non-human patients, e.g., primates, canines, equines, pigs, and felines. These other animals may undergo clinical or research therapies that may benefit from the subject matter of this disclosure.

[0117] Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the term “processor” as used herein may refer to any of the foregoing structure or any other physical structure suitable for implementation of the described techniques. Also, the techniques could be fully implemented in one or more circuits or logic elements.

[0118] This disclosure describes each of the following examples.

[0119] Example 1: an implantable medical device (IMD) comprising: an elongated body extending along a longitudinal axis and comprising: a distal section comprising a fixation mechanism configured to affix the distal section to wall tissue within a first chamber of a heart of the patient, a proximal section, and a medial section connecting the distal section to the proximal section, wherein the elongated body is configured to be entirely disposed within the vasculature of a patient, and wherein the proximal section is configured to be disposed within a second chamber of the heart or a blood vessel connected to the heart when the distal section is affixed to the first chamber; signal generation circuitry disposed within the elongated body; a first electrode disposed on or around the distal section and coupled to the signal generation circuitry; a second electrode disposed on or around the proximal section and coupled to the signal generation circuitry; and processing circuitry disposed within the elongated body, the processing circuitry being configured to: cause the signal generation circuitry to transmit a defibrillation pulse between the first electrode and the second electrode through cardiac tissue of the heart.

[0120] Example 2: the IMD of example 1, wherein the distal section comprises a distal rigid body, wherein the proximal section comprises a proximal rigid body, and wherein the medial section comprises a flexible body connecting the distal rigid body to the proximal rigid body.

[0121] Example 3 : the IMD of example 2, wherein the first electrode extends around an outer surface of the distal rigid body, and wherein the second electrode extends around an outer surface of the proximal rigid body.

[0122] Example 4: the IMD of any of examples 2 or 3, further comprising: one or more power sources disposed within one or more of the distal rigid body or the proximal rigid body, wherein the one or more power sources is configured to supply power to the signal generation circuitry.

[0123] Example 5: the IMD of any of examples 2-4, wherein one or more of the first electrode or the second electrode is disposed around an outer surface of the flexible body.

[0124] Example 6: the IMD of any of examples 2-5, further comprising one or more flexible capacitors extending along a length of the flexible body from the distal rigid body to the proximal rigid body.

[0125] Example 7: the IMD of any of examples 2-6, further comprising one or more power-generating elements, wherein the one or more power-generating elements isconfigured to generate electrical power in response to movement of the IMD as a result of mechanical movement of the heart.

[0126] Example 8: the IMD of any of examples 1-7, further comprising one or more of a third electrode or a sensor disposed along the flexible body.

[0127] Example 9: the IMD of example 8, wherein the proximal section is disposed within the blood vessel connected to the heart, wherein the first chamber of the heart and the blood vessel is separated by the second chamber, and wherein the one or more of the third electrode or the sensor is configured to be disposed within the second chamber.

[0128] Example 10: the IMD of any of examples 1-9, further comprising one or more sensors disposed on one or more of the distal section, the medial section, or the proximal portion, and wherein the processing circuitry is configured to sense, via the one or more sensors, signals indicative of one or more of an electrical stability of at least one chamber of the heart or a hemodynamic stability of the patient.

[0129] Example 11 : the IMD of any of examples 1-10, further comprising a plurality of electrodes, wherein the plurality of electrodes comprises the first electrode and the second electrode, and wherein the processing circuitry is configured to cause the signal generation circuitry to deliver a pacing signal to the cardiac tissue of the heart via at least two electrodes of the plurality of electrodes.

[0130] Example 12: the IMD of example 11, wherein the processing circuitry is configured to: determine a hemodynamic stability of the patient; cause, based on a determination that the hemodynamic stability of the patient satisfies a threshold condition, the signal generation circuitry to deliver the defibrillation shock pulse to the cardiac tissue via the first electrode and the second electrode; and cause, based on a determination that the hemodynamic stability of the patient does not satisfy the threshold condition, the signal generation circuitry to deliver the pacing signal to the cardiac tissue via the at least two electrodes.

[0131] Example 13: the IMD of any of examples 11 or 12, wherein the processing circuitry is configured to: determine an electrical stability of at least one chamber of the heart the patient; compare the determined electrical stability against a threshold electrical stability; cause, based on a determination that the electrical stability satisfies the threshold electrical stability, the signal generation circuitry to deliver the defibrillation shock pulse to the cardiac tissue via the first electrode and the second electrode; and cause, based on adetermination that the electrical stability does not satisfy the threshold electrical stability, the signal generation circuitry to deliver the pacing signal to the cardiac tissue via the at least two electrodes.

[0132] Example 14: the IMD of any of examples 12 or 13, wherein the first electrode and the second electrode defines a shock vector extending between the first electrode and the second electrode, and wherein the processing circuitry is configured to cause the signal generation circuitry to transmit the defibrillation shock pulse along the shock vector.

[0133] Example 15: the IMD of any of examples 1-14, wherein the first electrode comprises a first shock coil, and wherein the second electrode comprises a second shock coil.

[0134] Example 16: the IMD of any of examples 1-14, wherein the second electrode is configured to transition between a collapsed configuration and a radially expanded configuration extending away from the longitudinal axis.

[0135] Example 17: the IMD of any of examples 1-14, wherein a first electrically active outer surface of the distal section defines the first electrode, and wherein a second electrically active outer surface of the proximal section defines the second electrode.

[0136] Example 18: the IMD of any of examples 1-17, wherein the first chamber comprises one of: an atrium of the heart; or a ventricle of the heart.

[0137] Example 19: the IMD of any of examples 1-18, wherein the blood vessel comprises one of: a superior vena cava (SVC) of the patient; an inferior vena cava (IVC) of the patient; a pulmonary artery of the patient; or a coronary sinus of the patient.

[0138] Example 20: a method comprising: advancing a distal section of an elongated body an implantable medical device (IMD) into first chamber of a heart of a patient, wherein the IMD comprises: the elongated body, wherein the elongated body defines the distal section comprising a fixation mechanism, a proximal section, and a medial section connecting the distal section to the proximal section; signal generation circuitry disposed within the elongated body; processing circuitry disposed within the elongated body; a first electrode disposed on or around the distal section and coupled to the signal generation circuitry; and a second electrode disposed on or around the proximal section and coupled to the signal generation circuitry; affixing the distal section to wall tissue of the first chamber via the fixation mechanism; advancing the proximal section of the elongated body into one of a second chamber of the heart or a blood vessel connected to the heart;and causing, by the processing circuitry, the signal generation circuitry to transmit a defibrillation shock pulse to cardiac tissue of the heart via the first electrode and the second electrode.

[0139] Example 21 : the method of example 20, wherein the elongated body extends along a longitudinal axis, and wherein advancing the proximal section of the elongated body into the one of the second chamber or the blood vessel comprises: rotating a distal end of a tether assembly coupled to the proximal section of the elongated body relative to the longitudinal axis until the distal end of the tether assembly extends proximally along the longitudinal axis; advancing the distal end of the tether assembly proximally along the longitudinal axis to retract the proximal section of the elongated body proximally into the one of the second chamber or the blood vessel; and releasing the tether assembly from the proximal section of the elongated body within the one of the second chamber or the blood vessel.

[0140] Example 22: the method of any of examples 20 or 21, wherein the distal section comprises a distal rigid body, wherein the proximal section comprises a proximal rigid body, and wherein the medial section comprises a flexible body connecting the distal rigid body to the proximal rigid body.

[0141] Example 23: the method of example 22, wherein the IMD further comprises one or more power sources are disposed within one or more of the distal rigid body or the proximal rigid body.

[0142] Example 24: the method of any of examples 20-23, further comprising: sensing, by the processing circuitry, and via one or more sensors disposed on one or more of the distal section, the medial section, or the proximal section, physiological signals indicative of one or more of an electrical stability of at least one chamber of the heart or a hemodynamic stability of the patient.

[0143] Example 25: the method of any of examples 20-24, wherein the IMD further comprises a plurality of electrodes, the plurality of electrodes comprising the first electrode and the second electrode, wherein the plurality of electrodes are coupled to the signal generation circuitry, and wherein the method further comprises: receiving, by the processing circuitry, sensed signals indicating a hemodynamic status of the patient; comparing, by the processing circuitry, the hemodynamic status of the patient against a threshold condition; based on a determination that the hemodynamic status of the patientdoes not satisfy the threshold condition, causing, by the processing circuitry, the signal generation circuitry to transmit a pacing signal to the cardiac tissue of the heart via at least two electrodes of the plurality of electrodes; and based on a determination that the hemodynamic status of the patient satisfies the threshold condition, causing, by the processing circuitry, the signal generation circuitry to transmit the defibrillation shock pulse to the cardiac tissue of the heart via the first electrode and the second electrode.

[0144] Example 26: the method of any of examples 20-24, wherein the IMD further comprises a plurality of electrodes, the plurality of electrodes comprising the first electrode and the second electrode, wherein the plurality of electrodes are coupled to the signal generation circuitry, and wherein the method further comprises: receiving, by the processing circuitry, sensed signals indicating an electrical stability of at least one chamber of the heart; comparing, by the processing circuitry, the electrical stability against a threshold electrical stability; based on a determination that the electrical stability does not satisfy the threshold electrical stability, causing, by the processing circuitry, the signal generation circuitry to transmit a pacing signal to the cardiac tissue of the heart via at least two electrodes of the plurality of electrodes; and based on a determination that the electrical stability satisfies the threshold electrical stability, causing, by the processing circuitry, the signal generation circuitry to transmit the defibrillation shock pulse to the cardiac tissue of the heart via the first electrode and the second electrode.

[0145] Example 27: the method of any of examples 20-26, wherein the IMD further comprises one or more of a third electrode or a sensor disposed along the medical section.

[0146] Example 28: the method of example 27, wherein advancing the proximal section of the elongated body into one of the second chamber of the heart or the blood vessel connected to the heart comprises: advancing the proximal section into the blood vessel in a direction away from the heart until the one or more of the third electrode or the sensor is disposed within the second chamber, wherein the second chamber connects the first chamber to the blood vessel.

[0147] Example 29: the method of any of examples 20-28, wherein causing the signal generation circuitry to transmit the defibrillation shock pulse to the cardiac tissue of the heart via the first electrode and the second electrode comprises: causing, by the processing circuitry, the signal generation circuitry to transmit the defibrillation shock pulse from one of the first electrode or the second electrode to another of the first electrode or the secondelectrode along a shock vector extending between the first electrode and the second electrode.

[0148] Example 30: the method of any of examples 20-29, wherein the first electrode comprises a first shock coil, and wherein the second electrode comprises a second shock coil.

[0149] Example 31 : the method of any of examples 20-30, wherein advancing the proximal section of the elongated body into the one of the second chamber of the heart or the blood vessel connected to the heart comprises: radially expanding the second electrode from a collapsed configuration into an expanded configuration within the blood vessel.

[0150] Example 32: the method of any of examples 20-31, wherein a first electrically active outer surface of the distal section defines the first electrode, and wherein a second electrically active outer surface of the proximal section defines the second electrode.

[0151] Example 33: the method of any of examples 20-32, wherein the first chamber comprises one of: an atrium of the heart; or a ventricle of the heart.

[0152] Example 34: the method of any of examples 20-33, wherein the blood vessel comprises one of: a superior vena cava (SVC) of the patient; an inferior vena cava (IVC) of the patient; a pulmonary artery of the patient; or a coronary sinus of the patient.

[0153] Example 35: an implantable medical device (IMD) comprising: an elongated body extending along a longitudinal axis and comprising: a distal section comprising a fixation mechanism configured to affix the distal section to wall tissue within a chamber of a heart of a patient, a proximal section, and a medial section connecting the distal section to the proximal section; signal generation circuitry disposed within the elongated body; processing circuitry disposed within the elongated body; a first electrode disposed on or around the distal section and coupled to the signal generation circuitry; and a second electrode disposed on or around the proximal section and coupled to the signal generation circuitry, wherein the IMD is configured to be entirely disposed within a vasculature of a patient, and wherein the proximal section is configured to be disposed within one of : a superior vena cava (SVC) of the patient, an inferior vena cava (IVC) of the patient, or a coronary sinus of the patient when the distal section is affixed to the chamber, and wherein the processing circuitry is configured to: cause the signal generation circuitry to transmit a defibrillation shock pulse between the first electrode and the second electrode and into cardiac tissue of the heart.

[0154] Example 36: the IMD of example 35, wherein the chamber of the heart comprises one of: a right atrium of the heart; or a right ventricle of the heart.

[0155] Example 37: the IMD of any of examples 35 or 36, wherein the distal section comprises a distal rigid body, wherein the proximal section comprises a proximal rigid body, and wherein the medial section comprises a flexible body connecting the distal rigid body to the proximal rigid body.

[0156] Example 38: the IMD of example 37, wherein the first electrode extends around an outer surface of the distal rigid body, and wherein the second electrode extends around an outer surface of the proximal rigid body.

[0157] Example 39: the IMD of any of examples 37 or 38, further comprising: one or more power sources disposed within one or more of the distal rigid body or the proximal rigid body, wherein the one or more power sources is configured to supply power to the signal generation circuitry.

[0158] Example 40: the IMD of any of examples 37-39, wherein at least one of the first electrode or the second electrode is disposed around an outer surface of the flexible body.

[0159] Example 41 : the IMD of any of examples 37-40, further comprising one or more flexible capacitors extending along a length of the flexible body from the distal rigid body to the proximal rigid body.

[0160] Example 42: the IMD of any of examples 37-41, further comprising one or more power-generating elements, wherein the one or more power-generating elements is configured to generate electrical power in response to movement of the IMD as a result of mechanical movement of the heart.

[0161] Example 43: the IMD of any of examples 37-42, further comprising one or more of a third electrode or a sensor disposed along the flexible body.

[0162] Example 44: the IMD of example 43, wherein the chamber comprises a first chamber of the heart, wherein the first chamber of the heart and the blood vessel is separated by a second chamber of the heart, and wherein the one or more of the third electrode or the sensor is configured to be disposed within the second chamber.

[0163] Example 45: the IMD of any of examples 35-44, further comprising one or more sensors disposed on one or more of the distal section, the medial section, or the proximal section, and wherein the processing circuitry is configured to sense, via the oneor more sensors, signals indicative of one or more of an electrical stability of at least one chamber of the heart or a hemodynamic stability of the patient.

[0164] Example 46: the IMD of any of examples 35-45, further comprising a plurality of electrodes, the plurality of electrode comprising the first electrode and the second electrode, and wherein the processing circuitry is configured to cause the signal generation circuitry to transmit a pacing signal to the cardiac tissue of the heart via at least two electrodes of the plurality of electrodes.

[0165] Example 47: the IMD of example 46, wherein the processing circuitry is configured to: determine a hemodynamic stability of the patient; cause, based on a determination that the hemodynamic stability of the patient satisfies a threshold condition, the signal generation circuitry to deliver the defibrillation shock pulse to the cardiac tissue; and cause, based on a determination that the hemodynamic stability of the patient does not satisfy the threshold condition, the signal generation circuitry to deliver the pacing signal to the cardiac tissue via the at least two electrodes.

[0166] Example 48: the IMD of any of examples 46 or 47, wherein the processing circuitry is configured to: determine a ventricular electrical stability of the heart; compare the ventricular electrical stability against a threshold electrical stability; cause, based on a determination that the electrical stability satisfies the threshold electrical stability, the signal generation circuitry to deliver the defibrillation shock pulse to the cardiac tissue; and cause, based on a determination that the electrical stability does not satisfy the threshold electrical stability, the signal generation circuitry to deliver the pacing signal to the cardiac tissue via the at least two electrodes.

[0167] Example 49: the IMD of claim any of examples 47 or 48, wherein the first electrode and the second electrode defines a shock vector extending between the first electrode and the second electrode, and wherein the processing circuitry is configured to cause the signal generation circuitry to transmit the defibrillation shock pulse along the shock vector.

[0168] Various examples have been described. These and other examples are within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1. An implantable medical device (IMD) comprising:an elongated body extending along a longitudinal axis and comprising:a distal section comprising a fixation mechanism configured to affix the distal section to wall tissue within a first chamber of a heart of the patient,a proximal section, anda medial section connecting the distal section to the proximal section, wherein the elongated body is configured to be entirely disposed within the vasculature of a patient, and wherein the proximal section is configured to be disposed within a second chamber of the heart or a blood vessel connected to the heart when the distal section is affixed to the first chamber;signal generation circuitry disposed within the elongated body;a first electrode disposed on or around the distal section and coupled to the signal generation circuitry;a second electrode disposed on or around the proximal section and coupled to the signal generation circuitry; andprocessing circuitry disposed within the elongated body, the processing circuitry being configured to:cause the signal generation circuitry to transmit a defibrillation pulse between the first electrode and the second electrode through cardiac tissue of the heart.

2. The IMD of claim 1, wherein the distal section comprises a distal rigid body, wherein the proximal section comprises a proximal rigid body, and wherein the medial section comprises a flexible body connecting the distal rigid body to the proximal rigid body.

3. The IMD of claim 2, wherein the first electrode extends around an outer surface of the distal rigid body, and wherein the second electrode extends around an outer surface of the proximal rigid body.

4. The IMD of any of claims 2 or 3, further comprising:one or more power sources disposed within one or more of the distal rigid body or the proximal rigid body, wherein the one or more power sources is configured to supply power to the signal generation circuitry.

5. The IMD of any of claims 2-4, further comprising one or more flexible capacitors extending along a length of the flexible body from the distal rigid body to the proximal rigid body.

6. The IMD of any of claims 2-5, further comprising one or more powergenerating elements, wherein the one or more power-generating elements is configured to generate electrical power in response to movement of the IMD as a result of mechanical movement of the heart.

7. The IMD of any of claims 1-6, further comprising one or more of a third electrode or a sensor disposed along the flexible body, wherein the proximal section is disposed within the blood vessel connected to the heart, wherein the first chamber of the heart and the blood vessel is separated by the second chamber, and wherein the one or more of the third electrode or the sensor is configured to be disposed within the second chamber.

8. The IMD of any of claims 1-7, further comprising one or more sensors disposed on one or more of the distal section, the medial section, or the proximal portion, and wherein the processing circuitry is configured to sense, via the one or more sensors, signals indicative of one or more of an electrical stability of at least one chamber of the heart or a hemodynamic stability of the patient.

9. The IMD of any of claims 1-8, further comprising a plurality of electrodes, wherein the plurality of electrodes comprises the first electrode and the second electrode, and wherein the processing circuitry is configured to cause the signal generation circuitry to deliver a pacing signal to the cardiac tissue of the heart via at least two electrodes of the plurality of electrodes.

10. The IMD of claim 9, wherein the processing circuitry is configured to: determine a hemodynamic stability of the patient;cause, based on a determination that the hemodynamic stability of the patient satisfies a threshold condition, the signal generation circuitry to deliver the defibrillation shock pulse to the cardiac tissue via the first electrode and the second electrode; and cause, based on a determination that the hemodynamic stability of the patient does not satisfy the threshold condition, the signal generation circuitry to deliver the pacing signal to the cardiac tissue via the at least two electrodes.

11. The IMD of any of claims 9 or 10, wherein the processing circuitry is configured to:determine an electrical stability of at least one chamber of the heart the patient; compare the determined electrical stability against a threshold electrical stability;cause, based on a determination that the electrical stability satisfies the threshold electrical stability, the signal generation circuitry to deliver the defibrillation shock pulse to the cardiac tissue via the first electrode and the second electrode; and cause, based on a determination that the electrical stability does not satisfy the threshold electrical stability, the signal generation circuitry to deliver the pacing signal to the cardiac tissue via the at least two electrodes.

12. The IMD of any of claims 1-11, wherein the first electrode and the second electrode defines a shock vector extending between the first electrode and the second electrode, and wherein the processing circuitry is configured to cause the signal generation circuitry to transmit the defibrillation shock pulse along the shock vector.

13. The IMD of any of claims 1-12, wherein the first electrode comprises a first shock coil, and wherein the second electrode comprises a second shock coil.

14. The IMD of any of claims 1-12, wherein the second electrode is configured to transition between a collapsed configuration and a radially expanded configuration extending away from the longitudinal axis.

15. The IMD of any of claims 1-14, wherein the blood vessel comprises one of: a superior vena cava (SVC) of the patient;an inferior vena cava (IVC) of the patient;a pulmonary artery of the patient; ora coronary sinus of the patient.

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