Pulsed field ablation for cardiac tissue adjacent a nerve therapy site

Abstract

A medical device system includes an elongated structure configured to be navigated to an implantation site within a patient, at least one electrode carried on a distal portion of the elongated structure, and processing circuitry. The processing circuitry is configured to cause the at least one electrode, when proximate to the implantation site, to: deliver PF A energy to ablate a first type of tissue at the implantation site; and provide electrical neuromodulation therapy to a second type of tissue at the implantation site.

Description

PULSED FIELD ABLATION FOR CARDIAC TISSUE ADJACENT A NERVE THERAPY SITE

[0001] This application claims the benefit of and priority from U.S. Provisional Application Serial No. 63 / 712,131, filed October 25, 2024, the entire content of which is incorporated herein by reference.TECHNICAL FIELD

[0002] This disclosure relates generally to neuromodulation therapy and, more particularly, to devices configured to deliver pulsed field ablation in the vicinity of a location for neuromodulation therapy delivery.BACKGROUND

[0003] Medical device systems have been devised to provide electrical neuromodulation therapy to modify the functioning of the heart. For example, delivery of electrical therapy to the vagus nerve may therapeutically modulate, e.g., slow, the conduction response of the atrioventricular (AV) node. The therapy signal may be delivered to the AV node, or to other locations near cardiac tissue.SUMMARY

[0004] Medical device systems, such implantable medical device systems or partially implantable medical device systems, configured to provide electrical neuromodulation therapy to nerve tissue of the heart using electrodes may unintentionally activate cardiac tissue during the delivered therapy. Unintentional cardiac tissue activation may result in arrhythmia, such as atrial fibrillation (AF). In accordance with techniques of this disclosure, an ablation device may deliver pulsed field ablation (PF A) energy to cardiac tissue surrounding a target implantation site for electrodes that will deliver neuromodulation therapy. The delivered PFA may advantageously reduce or eliminate sensitivity of cardiac tissue while preserving integrity of nerve tissue at the target implantation site to the delivered therapy signal.

[0005] For instance, delivering PFA, e.g., irreversible electroporation (IRE) energy, to the cardiac tissue may physiologically modify the cells of the cardiac tissue to which the energy is applied. In some examples, depending on the characteristics of the electrical pulses, the cells may be irreversibly electroporated. When delivering energy to tissue using PFA, cardiac tissue may be affected more by the ablation than nerve tissue. As a result of being subjected to the electrical pulses, the energy gap between an amount of energy needed to cause an unintentional activationof the cardiac tissue and an amount of energy needed to provide neuromodulation therapy may increase, thereby reducing the chance of AF or other arrhythmia caused by cardiac tissue activation while providing neuromodulation therapy.

[0006] In some examples, the ablation device may deliver PFA via the therapy lead after the lead is implanted at the target location. In some examples, the ablation device may deliver PFA via at least one of the electrodes used for delivery of neuromodulation therapy. This may provide an advantage in that the beneficial cardiac tissue modification effects of the PFA may be well located to prevent side effects from neuromodulation therapy. In some examples, the medical device, e.g., implantable medical device, that delivers the neuromodulation therapy may also deliver the PFA, e.g., during an implantation procedure or otherwise prior to delivery of the neuromodulation therapy.

[0007] In some examples, a medical device comprises: an elongated structure configured to be navigated to an implantation site within a patient; at least one electrode carried on a distal portion of the elongated structure; and processing circuitry, wherein the processing circuitry is configured to cause the at least one electrode, when proximate to the implantation site, to: deliver PFA energy to ablate a first type of tissue at the implantation site; and provide electrical neuromodulation therapy to a second type of tissue at the implantation site.

[0008] In some examples, a medical device system comprises: an introducer defining a lumen; an implantable medical lead configured to be navigated to an implantation site within a patient using the introducer, wherein the lumen is sized to allow insertion of the implantable medical lead into the introducer; at least one electrode carried on a distal portion of the implantable medical lead; and processing circuitry, wherein the processing circuitry is configured to cause the at least one electrode, when proximate to the implantation site, to: deliver PFA energy to ablate a first type of tissue at the implantation site; provide electrical neuromodulation therapy to a second type of tissue at the implantation site.

[0009] In some examples, a method comprises: navigating an elongated structure to an implantation site within a patient, wherein the elongated structure carries at least one electrode on a distal portion of the elongated structure, and wherein navigating the elongated structure comprises navigating the at least one electrode to a position proximate to the implantation site; delivering, via the at least one electrode, PFA energy to ablate a first type of tissue at the implantation site; and providing, via the at least one electrode, electrical neuromodulation therapy to a second type of tissue at the implantation site.

[0010] The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 A is a conceptual diagram of an example implantable medical device system in accordance with techniques of this disclosure.

[0012] FIG. IB is a conceptual diagram of an example ablation system in accordance with techniques of this disclosure.

[0013] FIG. 2 is a conceptual diagram of an example implantation site before ablation in accordance with techniques of this disclosure.

[0014] FIG. 3 is a conceptual diagram of an example implantation site after an ablation procedure in accordance with techniques of this disclosure.

[0015] FIG. 4 is a conceptual diagram of an example implantation site after an ablation procedure in accordance with techniques of this disclosure.

[0016] FIG. 5 is a conceptual diagram of an example ablation device in accordance with the techniques of this disclosure.

[0017] FIG. 6 is a flow diagram that illustrates an example technique for providing neuromodulation therapy to a tissue of a patient.

[0018] FIGS. 7 A and 7B are graphs illustrating the voltage of atrioventricular nodal stimulation required to achieve neuromodulation before and after ablation, respectively.DETAILED DESCRIPTION

[0019] Many therapeutic techniques include delivery of therapeutic signals to certain tissue (e.g., nerve tissue) within the human body. However, it may be difficult to affect only the target tissue, and not also affect non-target tissue surrounding the target tissue. In certain body structures (e.g., the heart), neuromodulation of non-nerve tissue surrounding target nerve tissue may cause an unintentional activation of the non-nerve tissue. For example, a lead including one or more electrodes may be implanted within a heart of a patient. A medical device attached to the lead may include processing circuitry configured to provide electrical neuromodulation therapy to a vagus nerve of the patient or branch thereof, e.g., ganglia plexus near the AV node, via the one or more electrodes. The electrical therapy may unintentionally activate cardiac tissue of the patient near the vagus nerve, thereby causing AF or other undesirable activation of the cardiac tissue.

[0020] Before neuromodulation therapy is delivered to target tissue at an implantation site (e.g., a target site) for one or more therapy delivering electrodes, an ablation device may be configured to ablate non-target tissue surrounding or adjacent the target tissue, e.g., using the electrodes of the lead. The ablation energy may be controlled to destroy the non-target tissue at or near the implantation site, and controlled so as not to destroy the target tissue at the implantation site. Ablative destruction of the non-target tissue surrounding the target tissue may prevent the non-target tissue from activating in undesired ways when electrical neuromodulation therapy is provided to the target tissue.

[0021] Destruction of bodily tissue may introduce other undesirable complications. For example, ablation of cardiac tissue may not only prevent unintentional activation of the cardiac tissue, but also interfere with normal heart depolarization propagation through the cardiac tissue and prevent proper contraction of the cardiac muscle. Therefore, it may be advantageous to ablate no more non-target tissue (or modify the non-target tissue to no greater extent) than necessary. Furthermore, if the therapy electrodes are not implanted precisely at the location of the ablation, electrical neuromodulation of patient tissue via the IMD may still activate non-ablated, non-target tissue near the implantation site.

[0022] In accordance with techniques of this disclosure, a system may include an elongated structure configured to be navigated to an implantation site within the patient, and at least one electrode carried on a distal portion of the elongated structure. The at least one electrode may be configured, when proximate to the implantation site, to deliver pulsed field ablation (PF A) energy to ablate a first type of tissue at the implantation site and, in some examples, to provide electrical therapy to a second type of tissue at the implantation site. For example, a chronic therapy lead with one or more electrodes may be configured to perform both ablation of cardiac tissue, as well as electrical neuromodulation of a target nerve in a patient. In this way, it may be ensured that the lead delivers neuromodulation to patient tissue only in areas that have been subject to ablation energy. Furthermore, the lead may provide the minimal necessary ablation to prevent activation of the non-nerve tissue. In some examples, the lead may be configured for implantation in a heart of the patient, and may also be configured to provide electrical stimulation therapy to a vagus nerve of the patient or branch thereof. The vagus nerve may innervate the AV node (AVN), and AVN stimulation may thereby control a ventricular rate of the heart. In particular, electrical neuromodulation of the vagus nerve may significantly reduce the ventricular rate of the patient’s heart during atrial fibrillation (AF).

[0023] Although described primarily herein with reference to a medical lead implanted in a heart of a patient and configured to deliver electrical neuromodulation therapy to a vagus nerveof the patient, the assemblies and techniques described herein may be applicable to systems including medical leads configured to deliver other therapies and / or configured to be implanted in different locations within a patient.

[0024] FIG. 1A is a conceptual diagram of an example medical device system 100 in accordance with techniques of this disclosure. Medical device 100 may include an elongated structure configured to be navigated to an implantation site within patient 102. For example, system 100 includes an implantable medical lead 110 positioned at a target site 108 within a patient 102. Implantable medical lead 110 includes an elongated lead body 112 defining a distal portion 114 of implantable medical lead 110 (“lead distal portion 114”). Lead body 112 may be configured so that distal portion 114 may be navigated to a target site 108 within patient 102. In some examples, as illustrated in FIG. 1 A, target site 108 may include a portion of a heart 104, such as a wall of a right atrium (RA) of heart 104, or other locations within a body of patient 102. A clinician may maneuver lead distal portion 114 through the vasculature of patient 102 in order to position lead distal portion 114 at or near target site 108. For example, the clinician may guide lead distal portion 114 through the superior vena cava (SVC) and into the RA. In some examples, other pathways or techniques may be used to guide lead distal portion 114 into other target implantation sites within the body of patient 102. Medical device system 100 may include a delivery catheter and / or outer member (not shown), and implantable medical lead 110 may be guided and / or maneuvered within a lumen of the delivery catheter in order to approach target site 108. In some examples, medical device system 100 may include a stylet and / or guidewire for delivering distal portion 114 to target site 108.

[0025] System 100 includes an IMD 120 configured to provide electrical neuromodulation (e.g., atrioventricular node stimulation (AVNS)) to tissue of patient 102. For example, processing circuitry of IMD 120 may be configured to cause at least one electrode carried on distal portion 114 of lead 110 to provide neuromodulation to tissue proximate an implantation site (e.g., target site 108). In some examples, medical lead 110 may be configured to provide neuromodulation to a vagus nerve (or ganglia thereof) of patient 102 adjacent heart 104. For example, target site 108 may be an atrial wall of the patient’s heart 104. Fixation device 116 and or a part of distal portion 114 of lead 110 may be configured to pierce through cardiac tissue in the atrial wall to access ganglia plexi of the vagus nerve for neuromodulation thereof, neuromodulation of the vagus nerve may innervate the AVN, thereby controlling AV nodal conduction and / or a ventricular rate of heart 104. For example, electrical neuromodulation therapy of the vagus nerve may significantly reduce the ventricular rate of heart 104 during AF, e.g., due to conduction of the AF to the ventricles.

[0026] Implantable medical lead 110 may include fixation device 116 configured to penetrate cardiac tissue at or near target site 108. For example, fixation device 116 of implantable medical lead 110 may be configured to penetrate to a position at or near one or more ganglia plexi of the vagus nerve in heart 104. In some examples, fixation device 116 supports a fixation device electrode configured to, for example, ablate tissue surrounding the fixation device electrode and / or provide electrical neuromodulation therapy to the vagus nerve. In some examples, processing circuitry of IMD 120 may be configured to cause IMD 120 to ablate tissue surrounding one or more electrodes supported by fixation device 116 and or lead 110, as well as provide electrical neuromodulation therapy to the vagus nerve via the one or more electrodes. Fixation device 116 may be electrically connected to a conductor (not shown) extending through implantable medical lead 110 from fixation device 116. In examples, the conductor is electrically connected to therapy delivery circuitry of IMD 120. Processing circuitry, e.g., of IMD 120 may configure the therapy delivery circuitry to provide electrical signals to tissue through the conductor and fixation device 116 or other electrode of lead 110 (e.g., to the fixation device electrode). The electrical signals may include PFA signals to modify cardiac tissue and neuromodulation signals to modulate a nerve, e.g., the AVN and / or vagus nerve.

[0027] The electrical neuromodulation delivered via an electrode of lead 110 (e.g., by the fixation device electrode 116) to a target tissue type at an implantation site (e.g., target site 108) may unintentionally activate a non-target tissue type at the implantation site. In order to prevent unintentional activation of non-target tissue, at least one electrode of lead 110 may be configured, when proximate the implantation site, to ablate a first type of tissue at the implantation site before providing electrical neuromodulation to a second type of tissue at the implantation site. For example, processing circuitry may be configured to cause IMD 120 deliver PFA energy to ablate a first type of tissue at target site 108, and also be configured to cause IMD 120 to provide electrical neuromodulation therapy to a second type of tissue at target site 108 via the at least one electrode of lead 110.

[0028] In the example of FIG. 1 A, the electrical neuromodulation delivered via an electrode of lead 110 (e.g., by the fixation device electrode) to a vagus nerve of patient 102 may cause unintentional activation of cardiac tissue at the implantation site (e.g., target site 108), resulting in possible AF of heart 104. Before IMD 120 provides electrical neuromodulation therapy, IMD 120 and / or an ablation device (e.g., ablation device 121 of FIG. IB) may be configured to ablate cardiac tissue surrounding the one or more electrodes of lead 110 (e.g., the fixation device electrode). Ablating the cardiac tissue surrounding target site 108 may prevent activation of conduction system 106 during delivery of electrical neuromodulation therapy. Example methodsfor PFA are described in commonly assigned, co-pending U.S. Patent Publication No.2023 / 0310871 (Howard et al.), and U.S. Patent Publication No. 2024 / 0138908 (Stewart et al.), both of which are incorporated herein by reference in their entirety. For example, PFA energy may be delivered via a pulse train of energy having a predetermined frequency to patient tissue. The pulse train may include at least 2 pulses, an inter-phase delay between zero and 200 ms, an inter-pulse delay of at least 1 ms, and a pulse width between 1 and 3000 ps. In some examples, the pulse train of energy may have a voltage between 300V and 4000V, and the predetermined frequency may be approximately 1 kHz.

[0029] IMD 120 and / or the ablation device may be configured to deliver PFA energy to the tissue of patient 102 at target site 108 via one or more electrodes of lead 110. Nerve tissue may be more resistant to destruction than cardiac tissue when subjected to the PFA energy. Therefore, PFA of tissue at target site 108 may more effectively destroy or otherwise modify cardiac tissue at target site 108 than nerve tissue at target site 108. Because of this destruction, neuromodulation applied to tissue at target site 108 that is sufficient to provide therapy via the nerve tissue may be insufficient to unintentionally activate the cardiac tissue. In this way, unintentional activations of cardiac tissue (e.g., AF events) are prevented during therapy neuromodulation after ablation of tissue at the target site.

[0030] In examples, fixation device 116 defines an auger, helix screw, or other fixation device 116 extending distal to a distal end of lead distal portion 114. The helix screw may support the fixation device electrode. Fixation device 116 may be configured such that the helix screw engages tissues of target site 108 when the helix screw rotates about a longitudinal axis defined by lead body 112. For example, lead body 112 may be configured such that a torque on lead body 112 (e.g., on lead proximal portion 119) causes rotation of lead distal portion 114. In some examples, medical device 100 includes a delivery catheter defining a lumen (not shown). Implantable medical lead 110 (e.g., lead distal portion 114) may be configured to translate and / or rotate within the lumen.

[0031] FIG. IB is a conceptual diagram of an example ablation system 101 during an implant procedure using the implantable medical lead 110 of FIG. 1 A, in accordance with techniques of this disclosure. Ablation system 101 includes ablation device 121. Ablation system 101 may include an elongated structure configured to be navigated to an implantation site within a patient. For example, ablation system 101 includes implantable medical lead 110 configured to be delivered through incision site 109 on a body of patient 102 and introducer sheath 111 surrounding a portion of lead 110. Introducer sheath 111 may include a lumen through whichlead 110 may be guided and / or maneuvered in order to approach target site 108. In some examples, introducer sheath 111 may be a catheter.

[0032] In the example of FIG. IB, lead 110 is implanted at least partially within patient 102 through incision site 109. Although FIG. IB depicts lead 110 leading to an implant site in the heart of patient 102, components of system 101 described herein may be utilized with various types of implant tool systems, such as implant tool systems for delivering IMDs configured to deliver electrical therapy (e.g., cardiac electric therapy, neurostimulation), or other implant tool systems in other implant sites in a patient. In addition, it should be noted that system 101 may not be limited to treatment of a human patient. System 101 may be implemented in non-human patients, such as primates, canines, equines, pigs, ovines, bovines, felines, etc. These non-human patients may undergo clinical or research therapies that may benefit from the subject matter of this disclosure. Furthermore, although incision site 109 is pictured in FIG. IB as being located in the upper chest, in other examples it may be located anywhere on the body of patient 102.

[0033] In some examples, a clinician may insert lead 110 into and through a patient’s vasculature to target site 108 within a body of patient 102 (e.g., tissue of a heart of patient 102) where a medical procedure may be undertaken. For example, system 101 may include introducer sheath 111 defining a lumen. The lumen of introducer sheath 111 may be sized to allow insertion of lead 110 into introducer sheath 111. Introducer sheath 111 may first be inserted into and through patient’s vasculature to target site 108, and thereafter lead 110 may be inserted through the lumen of introducer sheath 111 to target site 108. Introducer sheath 111 may define at least one slot that exposes at least one electrode of lead 110 to patient tissue at target site 108 when the at least one electrode is proximate target site 108 and oriented relative to target tissue of patient 102. In some examples, the clinician may insert lead 110 under patient 102’s sternum and to a target site within the body of patient 102, rather than through the vasculature. Although incision site 109 is pictured in FIG. IB as being located in the upper chest, in other examples it may be located anywhere on the body of patient 102.

[0034] Lead 110 may include a proximal end and a distal end. In some examples the distal end of lead 110 may include one or more electrodes that rest against or are attached to patient tissue within patient 102. In some examples the proximal end may be connected to a housing of ablation device 121. In some examples, the housing of ablation device 121 may remain on the exterior of patient 102 with only lead 110 entering patient 102. Although only one lead is shown in FIG. IB, in some examples, ablation system 101 includes multiple leads 102.

[0035] A distal end of lead 110 may include a fixation electrode, e.g., fixation electrode 116 of FIG. 1 A. Ablation device 121 may be configured to deliver PFA energy to tissue of patient102 via the at least one electrode of lead 110. For example, the at least one electrode may be oriented relative to heart 104 of patient 102 at target site 108. Processing circuitry of ablation device 121 may be configured to control delivery of PFA energy to cardiac tissue of patient 102 at target site 108 via the at least one electrode. In some examples, ablation device 121 may be configured to deliver the PFA energy in a bipolar configuration, where an electrode on a distal portion of lead 110 acts as a first pole, and another electrode on the distal portion of lead 110 acts as the second pole. In some examples, a distal portion of introducer sheath 111 may include an electrode that acts as the second pole. In such examples, sheath 111 may be electrically coupled to ablation device 121. In some examples, a separate lead coupled to ablation device 121 may include an electrode that acts as the second pole. In some examples, the electrode on the second lead is an external patch or pad electrode. In some examples, rather than at least one electrode on lead, ablation device is coupled to sheath 111 and is configured to deliver PFA to cardiac tissue at the target site 108 via at least one electrode of sheath 111.

[0036] The distal portion of lead 110 may first be navigated to target site 108, and affixed to patient tissue at target site 108. For example, a distal electrode of lead 110 may be affixed to cardiac tissue at target site 108. Ablation device 121 may be coupled to lead 110 and may then deliver PFA energy to cardiac tissue of patient 102 at target site 108 via the at least one electrode of lead 110. For example, ablation device 121 may include processing circuitry configured to control the delivery of PFA via the at least one electrode when coupled to lead. In some examples, ablation device 121 may be configured to deliver neuromodulation via lead 110 prior to delivery of PFA, e.g., to confirm efficacy of neuromodulation at target site 108. In such examples, ablation device 121 may be configured to sense a response of target tissue at target site 108 to the neuromodulation. In some examples, ablation and / or neuromodulation efficacy testing may be performed by ablation device 121 via a separate mapping catheter rather than lead 110.

[0037] Thereafter, lead 110 may be connected to another device (e.g., IMD 120 of FIG. 1 A) configured to provide electrical neuromodulation therapy to patient 102 tissue at target site 108 via the at least one electrode. For example, processing circuitry of IMD 120 may be configured to control electrical neuromodulation therapy via the at least one electrode. IMD 120 may be implanted with lead 110 (as illustrated in FIG. 1 A) to provide chronic pacing therapy for patient 102 via the at least one electrode of lead 110. In other examples, e.g., as described with respect to FIG. 1A, IMD 120 may deliver PFA via at least one electrode of lead 110 prior to delivery of neuromodulation via the electrode. As illustrated in FIG. IB, target site 108 may be at or near the AV node and / or branches of the vagus nerve 130.

[0038] FIG. 2 is a conceptual diagram of an example implantation site 208 before ablation in accordance with techniques of this disclosure. Features of FIG. 2 may be substantially similar to like-named counterparts of FIGS. 1 A- IB. For example, lead 210 may be substantially similar to lead 110 of FIGS. 1A-1B.

[0039] A medical device system may include implantable medical lead 210 configured to be navigated to implantation site 208 within a patient. Lead 210 may carry at least one electrode on distal portion 214 of lead 210. In the example of FIG. 2, the at least one electrode includes ring electrode 218 and distal electrode 216. In the example of FIG. 2, distal electrode 216 is a helical electrode that supports fixation of distal electrode 216 in patient tissue. Lead 210 includes an elongated lead body defining a distal portion 214 of lead 210.

[0040] Ring electrode 218 and distal electrode 216 may be configured to be oriented relative to a heart of a patient. For example, implantation site 208 may include a portion of a heart, such as a wall of a right atrium (RA) of the heart, or other locations within a body of the patient.Tissue at the implantation site may include cardiac tissue 206, through which lead 210 is disposed to access vagus nerve 230 (e.g., one or more branches or ganglia plexi thereof). Vagus nerve 230 may be disposed within connective tissue 232 of the patient. Connective tissue 232 may include one or more of fat tissue and / or vessel tissue. A clinician may maneuver lead distal portion 214 through the vasculature of the patient in order to position lead distal portion 214 at or near target site 208.

[0041] It may be understood that references to one or more electrodes being configured to provide electrical neuromodulation therapy and / or PFA energy include circuitry (e.g., the circuitry described with respect to FIGS. 5A-5B) being configured to cause the one or more electrodes to deliver electrical neuromodulation therapy and / or PFA energy. For example, the circuitry may be configured to control delivery of electrical neuromodulation therapy and / or PFA energy using the one or more electrodes by controlling one or more stimulation parameters of the electrical neuromodulation therapy and / or PFA energy. In some examples, at least one electrode of lead 210 may be configured to provide electrical stimulation therapy to a first type of tissue at implantation site 208. For example, distal electrode 216 may be configured to provide electrical stimulation therapy to vagus nerve 230. Electrical neuromodulation delivered via distal electrode 216 may, by nature of distal electrode’s proximity to cardiac tissue 206, cause unintentional activation of cardiac tissue 206 at implantation site 208, resulting in possible AF of the heart. For example, stimulation zone 240 may be large enough to encompass cardiac tissue 206 such that sufficient energy is delivered to cardiac tissue 206 to cause propagation of an electrical signal 242 through cardiac tissue 206.

[0042] At least one electrode of lead 210 may be configured to deliver PF A energy to ablate a second type of tissue at implantation site 208. For example, processing circuitry of an ablation device connected to lead 210 may cause distal electrode 216 and / or ring electrode 218 to deliver PFA energy to the second type of tissue. Before processing circuitry of an IMD causes distal electrode 216 to provide electrical neuromodulation therapy to surrounding tissue, processing circuitry of the ablation device may cause distal electrode 216 and / or ring electrode 218 to ablate tissue surrounding distal electrode 216 and / or ring electrode 218. In some examples, distal electrode 216 and / or ring electrode 218 may be configured to deliver PFA energy to cardiac tissue 206. By ablating cardiac tissue 206 surrounding implantation site 208, distal electrode 216 and / or ring electrode 218 may prevent activation of the conduction system in cardiac tissue 206 during delivery of electrical neuromodulation therapy.

[0043] The PFA energy delivered to patient tissue may be configured to ablate one type of patient tissue, and not ablate another type of patient tissue. Because of the proximity of vagus nerve 230 to distal electrode 216 and / or ring electrode 218, vagus nerve 230 may also receive the PFA energy when distal electrode 216 and / or ring electrode 218 deliver PFA energy to cardiac tissue 206. However, the PFA energy delivered via distal electrode 216 and / or ring electrode 218 may be configured to ablate cardiac tissue 206 and not ablate vagus nerve 230. For example, cardiac tissue 206 may be more susceptible to cell death via PFA than nerve tissue. Therefore, a device may be configured to provide PFA energy to the patient’s tissue that is controlled to cause cell death in cardiac tissue 206, but not in vagus nerve 230. For example, processing circuitry of a device connected to lead 210 may be configured to control delivery of a pulse train of energy with particular voltages to patient tissue. For example, distal electrode 216 and / or ring electrode 218 may be configured to apply 400-1500 volts across patient tissue at implant site 208. In some examples, distal electrode 216 and / or ring electrode 218 may be configured to apply 500-1200 volts across patient tissue at implant site 208. In some examples, delivery of the PFA energy may temporarily stun vagus nerve 230. However, delivery of the PFA energy may kill cardiac tissue 206 surrounding the distal electrode 216 and / or ring electrode 218. Destruction of said cardiac tissue 206 may prevent cardiac tissue 206 from activating when electrical neuromodulation therapy is thereafter provided to vagus nerve 230.

[0044] FIG. 3 is a conceptual diagram of an example implantation site 308 after an ablation procedure in accordance with techniques of this disclosure. Features of FIG. 3 may be substantially similar to like-named counterparts of FIGS. 1A-2. For example, lead 310 may be substantially similar to lead 210 of FIG. 2.

[0045] A medical device may include implantable medical lead 310 configured to be navigated to implantation site 308 within a patient. Lead 310 may carry at least one electrode on distal portion 314 of lead 310. In the example of FIG. 3, the at least one electrode includes ring electrode 318 and distal electrode 316. In the example of FIG. 3, distal electrode 316 is a helical electrode that supports fixation of distal electrode 316 in patient tissue. Lead 310 includes an elongated lead body defining a distal portion 314 of lead 310.

[0046] As described above with reference to FIG. 2, one or more electrodes (e.g., distal electrode 316 and / or ring electrode 318) of a lead (e.g., lead 310) may be configured to deliver energy to ablate a first tissue type (e.g., cardiac tissue 306) before providing electrical neuromodulation therapy to another tissue type (e.g., vagus nerve 330). Ablating cardiac tissue 306 surrounding implantation site 308 may prevent activation of the conduction system in cardiac tissue 306 during delivery of electrical neuromodulation therapy. For example, ablation zone 344 (indicating a zone in which cardiac tissue is ablated or otherwise modified) may be sufficiently larger than stimulation zone 340 such that electrical stimulation applied to vagus nerve 330 by distal electrode 316 and / or ring electrode 318 is insufficient to activate cardiac tissue 306. In some examples, ablation zone 344 may represent the area in which cardiac tissue 306 has been ablated to the point of cell death. In some examples, stimulation zone 340 may represent an area in which energy from electrical neuromodulation by distal electrode 316 and / or ring electrode 318 may be sufficient to activate healthy nerve 330, and cardiac tissue 306 were it not ablated.

[0047] A size of ablation zone 344 may depend on the electrical parameters of the PFA performed, as well as on the structure of the electrodes performing the ablation. A size of stimulation zone 340 may depend on the amount of power or energy applied by distal electrode 316 and / or ring electrode 318 to patient tissue. For example, the applied electrical field can be expanded with increasing voltage, or its area of affect increased by increasing the number of deliveries / pulses, etc. that cells receive among other factors. The field that is applied is also determined by the geometry of the electrodes delivering the energy. For example if the electrodes are moved further apart, the area may get bigger, so long as the pulses have sufficient energy to provide the necessary effect to all the cells between the electrodes.

[0048] As described above with reference to FIG. 2, if cardiac tissue 306 is not ablated, electrical neuromodulation therapy by one or more of distal electrode 316 and / or ring electrode 318 may be sufficient to activate cardiac tissue 306. For example, stimulation zone 340 may be large enough to encompass cardiac tissue 306 such that sufficient energy is delivered to cardiac tissue 306 to cause propagation of an electrical signal 342 through cardiac tissue 306. However,electrical signal 342 may not be able to propagate through ablated cardiac tissue 306, thereby preventing potential AF that could be caused by electrical neuromodulation therapy.

[0049] The PFA energy delivered to patient tissue may be configured to ablate one type of patient tissue, and not ablate another type of patient tissue. Because of the proximity of vagus nerve 330 to distal electrode 316 and / or ring electrode 318, vagus nerve 330 may also receive the PFA energy when distal electrode 316 and / or ring electrode 318 are used to deliver PFA energy to cardiac tissue 306. However, distal electrode 316 and / or ring electrode 318 may be configured to ablate cardiac tissue 306 and not ablate vagus nerve 330. For example, cardiac tissue 306 may be more susceptible to cell death via PFA than nerve tissue. Therefore, distal electrode 316 and / or ring electrode 318 may be configured to provide PFA energy to the patient’s tissue that is controlled to cause cell death in cardiac tissue 306, but not in vagus nerve 330. In some examples, delivery of the PFA energy may temporarily stun vagus nerve 330. In some examples, delivery of the PFA energy may have no effect on vagus nerve 330. However, delivery of the PFA energy may destroy cardiac tissue 306 surrounding distal electrode 316 and / or ring electrode 318. Destruction of said cardiac tissue 306 may prevent cardiac tissue 306 from activating when electrical neuromodulation therapy is thereafter provided to vagus nerve 330.

[0050] Delivery of the PFA energy to two different types of patient tissue may increase a difference between a first amount of power required to provide electrical neuromodulation therapy to a first type of tissue and a second amount of power required to activate a second type of tissue at implantation site 308. For example, as a result of being subjected to the PFA energy, the power gap between an amount of power needed to cause an unintentional activation of cardiac tissue 306 and an amount of power needed to provide neuromodulation therapy to vagus nerve 330 may increase, thereby reducing the chance of AF while providing neuromodulation therapy. For example, delivery of PFA energy may temporarily stun vagus nerve 330, so that the nerve does not function for a stunning period. After the stunning period, vagus nerve 330 may return to normal operation, although a higher power level may be necessary to provide effective electrical neuromodulation therapy. In some examples, delivery of PFA energy destroys cardiac tissue 306 within ablation zone 344. Because of the destroyed cardiac tissue 306 closest to distal electrode 316 and / or ring electrode 318, an amount of electrical neuromodulation by distal electrode 316 and / or ring electrode 318 to cause activation of the non-destroyed cardiac tissue 306 may greatly increase. For example, the PFA may destroy cardiac tissue 306 within ablation zone 344, and in order to activate non-destroyed cardiac tissue 306 outside ablation zone 344, sufficient energy may need to be conferred to cardiac tissue 306 outside of ablation zone 344 to start propagation of an electric signal in cardiac tissue outside ablation zone 344. In oneexperimental example, before ablation, a power required to provide effective electrical stimulation therapy to vagus nerve 330 via distal electrode 316 and / or ring electrode 318 at implantation site 308 was around 2 volts. In one example, after ablation, a power required to provide effective electrical stimulation therapy to vagus nerve 330 via distal electrode 316 and / or ring electrode 318 at implantation site 308 was around 2.5 volts. In one example, before ablation, a power required to activate cardiac tissue 306 due to the electrical stimulation from distal electrode 316 and / or ring electrode 318 at implantation site 308 was around 4.5 volts. In one example, after ablation, a power required to activate cardiac tissue 306 due to the electrical stimulation from distal electrode 316 and / or ring electrode 318 at implantation site 308 was around 7 volts.

[0051] Because delivery of PFA energy in general may destroy some of cardiac tissue 306, there may be a risk that too much ablation of cardiac tissue 306 can impair normal operation of the heart. For example, electrical signals propagating through cardiac tissue 306 to cause normal heartbeat function may be interrupted or unevenly distributed through cardiac tissue 306 due to an area of destroyed cardiac tissue 306 through which the electrical signals cannot propagate. Therefore, to increase safety for a patient, distal electrode 316 and / or ring electrode 318 may be configured to ablate as little of cardiac tissue 306 as possible. For example, distal electrode 316 and / or ring electrode 318 may be configured to both deliver PFA energy and to provide electrical neuromodulation therapy. Distal electrode 316 and / or ring electrode 318 may be maneuvered to implantation site 308 and affixed to patient tissue before delivering PFA energy. In this way, the PFA energy is delivered only to the specific implantation site to destroy cardiac tissue 306 only at implantation site 308.

[0052] In examples where a first ablation lead ablates an area of patient tissue before a second therapy lead is implanted at the area, small discrepancies in the placement of the second lead may result in the second lead being displaced from a location where ablation was applied to patient tissue. This can defeat the purpose of the ablation, as the therapy lead may be close enough to non-ablated tissue to unintentionally activate the non-ablated tissue. In some examples, the first ablation lead may be used to ablate a large area of tissue to prevent unintentional activation of patient tissue via a displaced therapy lead, but excess ablation of patient tissue is disadvantageous as discussed above.

[0053] Therefore, examples according to this disclosure in which a single lead (e.g., lead 310) is used for both ablation and therapy delivery (e.g., via distal electrode 316 and / or ring electrode 318) may: save time during an implantation procedure by removing the need for an additional lead; prevent excess harm to patient tissue by only ablating the necessary amount oftissue (e.g., cardiac tissue 306) surrounding the implanted therapy electrodes; and provide fewer instances of unintentional activation of patient tissue at the implantation site (e.g., implantation site 308), as the therapy electrodes will be disposed at the center of the ablated area (e.g., ablation zone 344).

[0054] In some examples, in order to prevent excess ablation of patient tissue, lead 310 (e.g., processing circuitry and / or sensing circuitry of an IMD connected thereto) may be configured to measure an electrical response from patient tissue during an ablation procedure. For example, an IMD connected to lead 310 may be configured to sense an electrical response from a first type of patient tissue and / or a second type of patient tissue via electrodes of lead 310. In some examples, the first type of patient tissue is cardiac tissue 306 and the second type of patient tissue is nerve tissue (e.g., vagus nerve 330). During the ablation procedure, processing circuitry of the IMD may be configured to control delivery, via lead 310 and one or more electrodes thereof, of PFA energy using a defined pulse train with increasing voltage levels. For example, the IMD may first deliver 400 volts across patient tissue at implantation site 308, then measure an electrical response from one or more of cardiac tissue 306 and vagus nerve 330.

[0055] Sensing circuitry of the IMD may sense the electrical response using one or more of distal electrode 316 and / or ring electrode 318. The IMD may be configured to iteratively increase the voltage of the PFA energy delivered until the electrical response satisfies a threshold. For example, the IMD may measure an electrical response from patient tissue between each delivery of PFA energy until the electrical response reaches the desired level. In this way, no more PFA energy is applied to patient tissue than necessary to achieve a desired level of ablation and tissue response. Example electrical responses sensed via lead 110 include cardiac electrogram (EGM) amplitude, impedance, an induced response, e.g., an EMG invoked response to stimulation originated from lead 110 or elsewhere.

[0056] In some examples, sensing circuitry of an IMD connected to lead 310 may be configured to measure an electrical response from nerve tissue (e.g., vagus nerve 330) of the patient before affixing lead 310 at implantation site 308. For example, the sensing circuitry may measure an electrically evoked compound action potential (ECAP) of vagus nerve 330 to determine if placement of distal portion 314 of lead 310 in patient tissue will provide effective therapy to vagus nerve 330. Processing circuitry of the IMD may first cause one or more electrodes to electrically stimulate vagus nerve 330, and the sensing circuitry may measure the ECAP response. If the ECAP response satisfies a threshold, distal portion 314 of lead 310 may be affixed at that location.

[0057] FIG. 4 is a conceptual diagram of an example implantation site 408 after an ablation procedure in accordance with techniques of this disclosure. Features of FIG. 4 may be substantially similar to like-named counterparts of FIGS. 1A-3. For example, lead 410 may be substantially similar to lead 210 of FIG. 2.

[0058] A medical device may include implantable medical lead 410 configured to be navigated to implantation site 408 within a patient. Lead 410 may carry at least one electrode on distal portion 414 of lead 410. In the example of FIG. 4, the at least one electrode includes ring electrode 418 and distal electrode 416. In the example of FIG. 4, distal electrode 416 is a helical electrode that supports fixation of distal electrode 416 in patient tissue. Lead 410 includes an elongated lead body defining distal portion 414 of lead 410.

[0059] In some examples, a single electrode of a lead may be configured to ablate a first tissue type (e.g., cardiac tissue 406) before providing electrical neuromodulation therapy to another tissue type (e.g., vagus nerve 430). In some examples, distal electrode 416 or ring electrode 418 of lead 410 may be configured to ablate cardiac tissue 406 in a unipolar configuration. In the example of FIG. 4, distal electrode 416 has been used to ablate cardiac tissue in a unipolar configuration. For example, ablation delivery may be performed between distal electrode 416 and an otherwise located polarity (e.g., a ground patch or an alternate catheter).

[0060] Distal electrode 416 may be configured to deliver PF A energy to cardiac tissue 406 to ablate cardiac tissue 406. By ablating cardiac tissue 406 surrounding implantation site 408, distal electrode 416 may prevent activation of the conduction system in cardiac tissue 406 during delivery of electrical neuromodulation therapy. For example, ablation zone 444 may be sufficiently larger than stimulation zone 440 such that electrical neuromodulation applied to vagus nerve 430 by distal electrode 416 is insufficient to activate cardiac tissue 406. In some examples, ablation zone 444 may represent the area in which cardiac tissue 406 has been ablated to the point of cell death. In some examples, stimulation zone 440 may represent an area in which energy from electrical neuromodulation by distal electrode 416 may be sufficient to activate healthy cardiac tissue 406. A size of ablation zone 444 may depend on the electrical parameters of the PFA performed, as well as on the structure of the electrodes performing the ablation. A size of stimulation zone 440 may depend on the amount of power or energy applied by distal electrode 416 to patient tissue.

[0061] As described above, if cardiac tissue 406 is not ablated, electrical neuromodulation therapy by distal electrode 416 may be sufficient to activate cardiac tissue 406. For example, stimulation zone 440 may be large enough to encompass cardiac tissue 406 such that sufficientenergy is delivered to cardiac tissue 406 to cause propagation of an electrical signal 442 through cardiac tissue 406. However, electrical signal 442 may not be able to propagate through ablated cardiac tissue 406, thereby preventing potential AF that could be caused by electrical neuromodulation therapy.

[0062] The PFA energy delivered to patient tissue may be configured to ablate one type of patient tissue, and not ablate another type of patient tissue. Because of the proximity of vagus nerve 430 to distal electrode 416, vagus nerve 430 may also receive the PFA energy when distal electrode 416 are used to deliver PFA energy to cardiac tissue 406. However, distal electrode 416 may be configured to ablate cardiac tissue 406 and not ablate vagus nerve 430. For example, cardiac tissue 406 may be more susceptible to cell death via PFA than nerve tissue. Therefore, distal electrode 416 may be configured to provide PFA energy to the patient’s tissue that is controlled to cause cell death in cardiac tissue 406, but not in vagus nerve 430. In some examples, delivery of the PFA energy may temporarily stun vagus nerve 430. In some examples, delivery of the PFA energy may have no effect on vagus nerve 430. However, delivery of the PFA energy may destroy cardiac tissue 406 surrounding distal electrode 416. Destruction of said cardiac tissue 406 may prevent cardiac tissue 406 from activating when electrical neuromodulation therapy is thereafter provided to vagus nerve 430. For example, processing circuitry connected to lead 410 may be configured to control delivery of a pulse train of energy with particular voltages to patient tissue. For example, distal electrode 416 may be configured to deliver a pulse train of energy with a voltage in the range of 400-1500 volts across patient tissue at implant site 408. In some examples, distal electrode 216 may be configured to deliver a pulse train of energy with a voltage in the range of 500-1200 volts across patient tissue at implant site 408. In some examples, delivery of the PFA energy may temporarily stun vagus nerve 430. However, delivery of the PFA energy may kill cardiac tissue 406 surrounding the distal electrode 416. Destruction of said cardiac tissue 406 may prevent cardiac tissue 406 from activating when electrical neuromodulation therapy is thereafter provided to vagus nerve 430.

[0063] FIG. 5 is a conceptual diagram of an example ablation device 501 in accordance with the techniques of this disclosure. Features of FIG. 5 may be substantially similar to like-named counterparts of FIGS. IB-4. For example, lead 510 may be substantially similar to lead 110 of FIG. IB.

[0064] Ablation device 501 may be used in situations in which the neuromodulation delivering medical device, e.g., IMD, is not configured to deliver ablation. In such examples, ablation device 501 may be coupled to the lead that will be used for neuromodulation prior to the neuromodulation device. However, in some examples an IMD may be configured to deliverablation, e.g., PF A, such as described above. In general, the ablation, neuromodulation, pacing, and sensing functionality described herein may be implemented in any one or more devices and via any one or more leads or other electrode-carrying structures. Such leads or other structures, when described as delivering ablation or therapy, or sensing signals, may be controlled to do so by a connected device as described herein.

[0065] Ablation device 501 includes housing 521 with includes signal generator 547, processing circuitry 551, communication circuitry 561, sensing circuitry 559, therapy delivery circuitry 555, ablation circuitry 553, a power source 565, and / or a memory 563. Ablation device 501 may be electrically connected to electrode 516 via lead 510. Although only one electrode is depicted, in some examples, ablation device 501 may include more than one electrode. Lead 510 may be configured to be navigated to an implantation site within a patient. Housing 521 may be configured to enclose processing circuitry 551, ablation circuitry 553, therapy delivery circuitry 555, sensing circuitry 559, communication circuitry 561, memory 563, power source 565 and / or other circuitry within ablation device 501. Housing 521 may be configured to fluidly isolate the circuitry of ablation device 501 from an environment in contact with an exterior surface of housing 521 (e.g., an internal environment of a patient).

[0066] In some examples, memory 563 includes computer-readable instructions that, when executed by processing circuitry 551, cause ablation device 501 and processing circuitry 551 to perform various functions attributed herein to ablation device 501 and processing circuitry 551. Memory 563 may include any volatile, non-volatile, magnetic, optical, or electrical media, such as a random access memory 563 (RAM), read-only memory 563 (ROM), non-volatile RAM (NVRAM), electrically-erasable programmable ROM (EEPROM), ferroelectric RAM (FRAM), flash memory 563, or any other digital media.

[0067] Processing circuitry 551, ablation circuitry 553, therapy delivery circuitry 555, sensing circuitry 559, communication circuitry 561, and / or other circuitry may include fixed function circuitry and / or programmable processing circuitry 551. Processing circuitry 551, ablation circuitry 553, therapy delivery circuitry 555, sensing circuitry 559, communication circuitry 561, and / or other circuitry 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), or equivalent discrete or analog logic circuitry. In some examples, Processing circuitry 551, ablation circuitry 553, therapy delivery circuitry 555, sensing circuitry 559, communication circuitry 561, and / or other circuitry may include multiple components, such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, or one or more FPGAs, as well as other discrete orintegrated logic circuitry. The functions attributed to processing circuitry 551, therapy delivery circuitry 555, sensing circuitry 559, communication circuitry 561, and / or other circuitry herein may be embodied as software, firmware, hardware or any combination thereof.

[0068] In some examples, processing circuitry 551, ablation circuitry 553, therapy delivery circuitry 555, sensing circuitry 559, and / or other circuitry may receive (e.g., from an external device), via communication circuitry 561, a respective value for each of a plurality of cardiac sensing parameters, ablation parameters, and / or electrode vectors. Processing circuitry 551, ablation circuitry 553, sensing circuitry 559, and / or other circuitry may store such parameters and / or electrode vectors in memory 563. Ablation circuitry 553 may include capacitors, current sources, and / or regulators.

[0069] Processing circuitry 551 and sensing circuitry 559 may be configured to monitor signals from electrode 516 in order to monitor electrical activity of patient tissue. Sensing circuitry 559 may include circuits that acquire electrical signals, such as filters, amplifiers, and analog-to-digital circuitry. Electrical signals acquired by sensing circuitry 559 may include intrinsic and / or paced cardiac electrical activity, such as atrial depolarizations and / or ventricular depolarizations, and activations indicating a response of nerve tissue to neuromodulation.Sensing circuitry 559 may filter, amplify, and digitize the acquired electrical signals to generate raw digital data. Processing circuitry 551 may receive the digitized data generated by sensing circuitry 559. In some examples, processing circuitry 551 may perform various digital signal processing operations on the raw data, such as digital filtering. Communication circuitry 561 may include any suitable hardware (e.g., an antenna), firmware, software, or any combination thereof for communicating with another device, e.g., external to the patient. In some examples, during the implantation process, processing circuitry 551 may routinely analyze the data generated by sensing circuitry 559 to determine if placement of lead 510 within patient is sufficient for accurate sensing and / or neuromodulation therapy using the electrode(s) of lead 510. Electrode 516 of lead 510 may be electrically connected to sensing circuitry 559 via a conductor. Sensing circuitry 559 may be configured to sense electrical activity of heart via electrode 516.

[0070] Signal generator 547 may be selectively coupled to electrode 516. Signal generator 547 may be configured to provide electrical pulses to electrode 516 to perform an ablation procedure. For example, signal generator 547 may be configured and programmed to deliver pulsed, high-voltage electric fields appropriate for achieving desired pulsed, high-voltage ablation via IRE and / or pulsed RF ablation. Signal generator 547 may also be configured as directed by therapy delivery circuitry 555 to deliver neuromodulation therapy to test a suitableness of a target site.

[0071] The electrical neuromodulation delivered via electrode 516 to a target tissue type at a target site may unintentionally activate a non-target tissue type at the target site. In order to prevent unintentional activation of non-target tissue, electrode 516 may be configured to ablate a first type of tissue at the implantation site before providing electrical neuromodulation to a second type of tissue at the implantation site. For example, before implantation of IMD 500 in a patient for chronic neuromodulation therapy, ablation device 501 may be configured to deliver PFA energy to ablate tissue surrounding electrode 516 using electrode 516. In some examples, processing circuitry 551 (e.g., via ablation circuitry 553 thereof) may be configured to cause electrode 516 to deliver PFA energy to ablate cardiac tissue surrounding electrode 516. By ablating the cardiac tissue surrounding target site, ablation device 501 may prevent activation of a conduction system of a heart during delivery of AVN stimulation to the vagus nerve via IMD 500. In some examples, electrode 516 may be configured to deliver PFA energy to ablate cardiac tissue at the target site, and be configured to thereafter provide AVN stimulation to a vagus nerve of the patient at the target site. For example lead 510 may be connected to ablation device 501, and electrode 516 may be configured to deliver PFA energy to ablate cardiac tissue at an implant site (e.g., ablation circuitry 553 may be configured to control delivery of PFA energy to ablate the cardiac tissue via electrode 516). Thereafter, lead 510 may be connected to IMD 500, and electrode 516 may be configured to provide electrical neuromodulation therapy (e.g., AVN stimulation) to a vagus nerve at the target site (e.g., therapy delivery circuitry 554 may be configured to control electrical neuromodulation therapy via electrode 516).

[0072] Nerve tissue may be more resistant to destruction than cardiac tissue when subjected to the PFA energy. Therefore, PFA of tissue at the target site may more effectively destroy cardiac tissue at the target site than nerve tissue at target site. Because of this destruction, neuromodulation applied to tissue at the target site that is sufficient to provide therapy via the nerve tissue may be insufficient to unintentionally activate the cardiac tissue. In this way, unintentional activations of cardiac tissue (e.g., AF events) are prevented during therapy neuromodulation after ablation of tissue at the target site.

[0073] In some examples, processing circuitry 551 and ablation circuitry 553 are configured to cause ablation of the cardiac tissue in a bipolar configuration via two electrodes 516. For example, electrode 516 may act as one pole and an additional electrode (not shown) may act as the other pole to create a voltage difference therebetween and across patient tissue. In some examples, electrode 516 may act as a first pole for performing bipolar ablation, and the second pole may be an additional electrode located on a distal portion lead 510. In some examples, the second pole may be an electrode located on a separate lead that is also at or in close proximitywith the implantation site. In some examples, the second pole may be located on a distal portion of an introducer (e.g., introducer sheath 111 of FIG. IB) at or in close proximity to the implantation site.

[0074] Although only one electrode is shown in FIGS. 5A-5B, in some examples lead 510 may include more electrodes. For example, lead 510 may include two or more electrodes, wherein the two or more electrodes comprise a first set of one or more electrodes and a second set of one or more electrodes, wherein the second set of one or more electrodes is separate from the first set of one or more electrodes. For example, processing circuitry 551 may be configured to control delivery of PFA energy via the first set of one or more electrodes, and processing circuitry 550 may be configured to control electrical neuromodulation therapy via the second set of one or more electrodes that is comprised of different electrodes from the first set. In other examples, the first set of one or more electrodes may include at least one electrode in common with the second set of one or more electrodes, such that at least one electrode is configured to both deliver PFA energy as well as provide electrical neuromodulation therapy. In some examples, the first set of one or more electrodes may be disposed on lead 510, and the second set of one or more electrodes may be disposed on another lead, a separate catheter, or other structure.

[0075] The PFA energy delivered to patient tissue may be configured to ablate one type of patient tissue, and not ablate another type of patient tissue. Because of the proximity of two different types of patient tissue to the implantation site, both types of tissue may receive the PFA energy when ablation device 501 delivers the PFA energy to patient tissue via electrode 516. However, processing circuitry 551 (e.g., in conjunction with ablation circuitry 553) may be configured to control delivery of PFA energy that ablates one type of tissue and not the other. For example, processing circuitry 551 may be configured to control delivery of PFA energy that ablates the cardiac tissue and does not ablate the vagus nerve at the implantation site. For example, the cardiac tissue may be more susceptible to cell death via PFA than nerve tissue. Therefore, processing circuitry 551 may be configured to control delivery of PFA energy to the patient’s tissue to cause cell death in the cardiac tissue, but not in the vagus nerve. In some examples, delivery of the PFA energy may temporarily stun the vagus nerve. In some examples, delivery of the PFA energy may have no effect on the vagus nerve. However, delivery of the PFA energy may destroy the cardiac tissue surrounding electrode 516. Destruction of said cardiac tissue may prevent cardiac tissue from activating when AVN stimulation is thereafter provided to the vagus nerve. For example, processing circuitry 551 may be configured to control delivery of a pulse train of energy with particular voltages to the patient tissue. For example, processing circuitry 551 may be configured to control delivery of a pulse train of energy with a voltage inthe range of 400-1500 volts across patient tissue at the implantation site via electrode 516. In some examples, processing circuitry 551 may be configured to control delivery of a pulse train of energy with a voltage in the range of 500-1200 volts across patient tissue at the implantation site. In some examples, delivery of the PFA energy may temporarily stun the vagus nerve. However, delivery of the PFA energy may kill the cardiac tissue surrounding electrode 516. Destruction of said cardiac tissue may prevent the cardiac tissue from activating when AVN stimulation is thereafter provided to the vagus nerve.

[0076] Because delivery of PFA energy in general may destroy some of the cardiac tissue, there may be a risk that too much ablation of the cardiac tissue can impair normal operation of the heart. For example, electrical signals propagating through the cardiac tissue to cause normal heartbeat function may be interrupted or unevenly distributed through the cardiac tissue due to an area of destroyed cardiac tissue through which the electrical signals cannot propagate. Therefore, to increase safety for a patient, IMD 501 may be configured to ablate as little of the cardiac tissue as possible. For example, lead 510 may be configured to both deliver PFA energy and to provide electrical neuromodulation therapy (e.g., AVN stimulation) via one or more electrodes of lead 510 (e.g., electrode 516). Electrode 516 may be maneuvered to the implantation site and affixed to patient tissue before delivering PFA energy. In this way, the PFA energy is delivered only to the specific implantation site to destroy the cardiac tissue only at the implantation site surrounding electrode 516 after implantation.

[0077] In examples where a first ablation lead ablates an area of patient tissue before a second therapy lead is implanted at the area, small discrepancies in the placement of the second lead may result in the second lead being affixed at a slightly different location from where ablation was applied to patient tissue. This can either defeat the purpose of the ablation, as the therapy lead may be close enough to non-ablated tissue to unintentionally activate the nonablated tissue, or the first ablation lead may be used to ablate a large area of tissue to prevent unintentional activation of patient tissue via the misplaced therapy lead. Excess ablation of patient tissue is disadvantageous as discussed above.

[0078] Therefore examples according to this disclosure in which a single lead (e.g., lead 510) includes both ablation and therapy delivery electrodes (e.g., electrode 516) may: save time during an implantation procedure by removing the need for an additional lead; prevent excess harm to patient tissue by only ablating the necessary amount of tissue surrounding the implanted therapy electrode(s); and provide fewer instances of unintentional activation of patient tissue at the implantation site, as the therapy electrodes will be disposed at the same location where ablation was performed.

[0079] In some examples, in order to prevent excess ablation of patient tissue, processing circuitry 551 and sensing circuitry 559 may be configured to measure an electrical response from patient tissue during an ablation procedure. For example, during the ablation procedure, processing circuitry 551, via electrode 516, may control delivery of PF A energy using a defined pulse train with increasing voltage levels. In some examples, electrode 516 may first deliver 400 volts across patient tissue at the implantation site, then measure an electrical response from one or more of the cardiac tissue and the vagus nerve sensed by sensing circuitry 559. Sensing circuitry 559 may sense the electrical response via electrode 516. Processing circuitry 551 may be configured to iteratively increase the voltage of the PFA energy delivered until the electrical response satisfies a threshold. For example, sensing circuitry 559 may measure an electrical response from patient tissue between each delivery of PFA energy until the electrical response reaches the desired level. In this way, no more PFA energy is applied to patient tissue than necessary to achieve a desired level of ablation and tissue response.

[0080] In some examples, sensing circuitry 559 may be configured to measure an electrical response from nerve tissue (e.g., the vagus nerve) of the patient to neuromodulation delivered, e.g., by ablation device 501, before lead 510 (and electrode 516) is affixed at the implantation site. For example, sensing circuitry 559 may measure an electrically evoked compound action potential (ECAP) of the vagus nerve to determine if placement of distal portion of lead 510 in patient tissue will provide effective therapy to the vagus nerve. Therapy delivery circuitry 555 may first electrically stimulate the vagus nerve, and sensing circuitry 559 may thereafter measure the ECAP response. If the ECAP response satisfies a threshold, distal portion of lead 510 may be affixed at that location.

[0081] FIG. 6 illustrates an example technique for providing electrical neuromodulation therapy to a tissue of a patient. Reference may be made to reference numerals of FIGS. 1 A-5B to assist in describing the disclosed technique.

[0082] The method may include navigating a lead to an implantation site within a patient (600). A medical device system (e.g., system 101 of FIG. IB) may include ablation device 121. Ablation device 121 may include an elongated structure configured to be navigated to an implantation site within a patient. For example, ablation system 101 includes implantable medical lead 110 configured to be delivered through incision site 109 on a body of patient 102 and introducer sheath 111 surrounding a portion of lead 110. Introducer sheath 111 may include a lumen through which lead 110 may be guided and / or maneuvered in order to approach target site 108. In some examples, introducer sheath 111 may be a catheter.

[0083] In the example of FIG. IB, lead 110 is implanted at least partially within patient 102 through incision site 109. Although FIG. IB depicts lead 110 leading to an implant site in the heart of patient 102, components of system 101 described herein may be utilized with various types of implant tool systems, such as implant tool systems for delivering IMDs configured to deliver electrical neuromodulation therapy (e.g., cardiac electric therapy, neurostimulation), or other implant tool systems in other implant sites in a patient. Furthermore, although incision site 109 is pictured in FIG. IB as being located in the upper chest, in other examples it may be located anywhere on the body of patient 102.

[0084] In some examples, a clinician may insert lead 110 into and through a patient’s vasculature to target site 108 within a body of patient 102 (e.g., tissue of a heart of patient 102) where a medical procedure may be undertaken. For example, system 101 may include introducer sheath 111 defining a lumen. The lumen of introducer sheath 111 may be sized to allow insertion of lead 110 into introducer sheath 111. Introducer sheath 111 may first be inserted into and through patient’s vasculature to target site 108, and thereafter lead 110 may be inserted through the lumen of introducer sheath 111 to target site 108. Introducer sheath 111 may define at least one slot that exposes at least one electrode of lead 110 to patient tissue at target site 108 when the at least one electrode is proximate target site 108 and oriented relative to target tissue of patient 102. In some examples, the clinician may insert lead 110 under patient 102’s sternum and to a target site within the body of patient 102, rather than through the vasculature. The method may include navigating the at least one electrode to a position proximate the implantation site. For example, the at least one electrode may be oriented relative to heart 104 of patient 102 at target site 108.

[0085] The method may further include delivering, via the at least one electrode, PFA energy to a first type of tissue at the implantation site (602). An ablation device (e.g., ablation device 501 of FIG. 5) may be configured to deliver PFA energy to ablate tissue surrounding electrode 516. In some examples, processing circuitry 551 (e.g., via ablation circuitry 553 thereof) may be configured to cause electrode 516 to deliver PFA energy to ablate cardiac tissue surrounding electrode 516.

[0086] As described herein, the method may include sensing efficacy of neuromodulation at an implant site and / or capture thresholds of first and / or second types of tissue. Such evaluations may occur prior to and / or after delivery of PFA. In some examples, multiple target sites may be evaluated and / or tested post ablation as part of the techniques descried herein. In some examples, neuromodulation parameters and / or tissue capture or entrainment thresholds may be determined in a manual or automated assessment post-PFA or other ablation delivery. In suchexamples, further PFA may be delivered based on such an assessment, e.g., in an iterative manner.

[0087] The method may further include providing electrical neuromodulation therapy to a second type of tissue at the implantation site (604). After ablating tissue, lead 510 may be attached to an IMD (e.g., IMD 120 of FIG. 1 A). IMD 120 may be configured to provide electrical neuromodulation therapy to target tissue of a patient. For example, processing circuitry of IMD 120 may be configured to cause electrode 516 carried on a distal portion of lead 510 to provide AVN stimulation to patient tissue when proximate an implantation site (e.g., a vagus nerve in a heart of the patient). Neuromodulation of the vagus nerve may innervate the AVN, thereby controlling a ventricular rate of heart. For example, electrical neuromodulation therapy of the vagus nerve may significantly reduce the ventricular rate of heart during AF. In some examples,

[0088] The electrical neuromodulation delivered via electrode 516 to a target tissue type at a target site may unintentionally activate a non-target tissue type at the target site. In order to prevent unintentional activation of non-target tissue, electrode 516 may be configured to ablate a first type of tissue at the implantation site before providing electrical neuromodulation to a second type of tissue at the implantation site (as in step 602). For example, processing circuitry 551 may be configured to control delivery of PFA energy to ablate cardiac tissue at the target site, and processing circuitry of IMD 120 may be configured to thereafter control AVN stimulation to a vagus nerve of the patient at the target site via electrode 516. By ablating the cardiac tissue surrounding target site, the system described herein may prevent activation of a conduction system of a heart during delivery of AVN stimulation to the vagus nerve.

[0089] Nerve tissue may be more resistant to destruction than cardiac tissue when subjected to the PFA energy. Therefore, PFA of tissue at the target site may more effectively destroy cardiac tissue at the target site than nerve tissue at target site. Because of this destruction, neuromodulation applied to tissue at the target site that is sufficient to provide therapy via the nerve tissue may be insufficient to unintentionally activate the cardiac tissue. In this way, unintentional activations of cardiac tissue (e.g., AF events) are prevented during therapy neuromodulation after ablation of tissue at the target site.

[0090] In some examples, electrode 516 is configured to ablate the cardiac tissue in a bipolar configuration. For example, electrode 516 may act as one pole and an additional electrode may act as the other pole to create a voltage difference therebetween and across patient tissue. In some examples, electrode 516 may act as a first pole for performing bipolar ablation, and the second pole may be an additional electrode located on a distal portion lead 510. In some examples, thesecond pole may be an electrode located on a separate lead that is also at or in close proximity with the implantation site. In some examples, the second pole may be located on a distal portion of an introducer (e.g., introducer sheath 111 of FIG. IB) at or in close proximity to the implantation site.

[0091] Although only one electrode is shown in FIG. 5 in some examples lead 510 may include more electrodes. For example, lead 510 may include two or more electrodes, wherein the two or more electrodes comprise a first set of one or more electrodes and a second set of one or more electrodes, wherein the second set of one or more electrodes is separate from the first set of one or more electrodes. For example, the first set of one or more electrodes may be configured to control delivery of PFA energy, and the second set of one or more electrodes may be configured to provide electrical neuromodulation therapy, wherein the second set of one or more electrodes that is comprised of different electrodes from the first set. In other examples, the first set of one or more electrodes may include at least one electrode in common with the second set of one or more electrodes, such that at least one electrode is configured to both deliver PFA energy as well as provide electrical neuromodulation therapy. In some examples, the first set of one or more electrodes may be disposed on lead 510, and the second set of one or more electrodes may be disposed on another lead, a separate catheter, an IMD housing, an external patch, or other structure.

[0092] The PFA energy delivered to patient tissue may be configured to ablate one type of patient tissue, and not ablate another type of patient tissue. Because of the proximity of two different types of patient tissue to the implantation site, both types of tissue may receive the PFA energy when electrode 516 delivers the PFA energy to patient tissue. However, processing circuitry 551 may be configured to control delivery of PFA energy that ablates one type of tissue and not the other. For example, processing circuitry 551 may be configured to control delivery of PFA energy that ablates the cardiac tissue and does not ablate the vagus nerve at the implantation site. For example, the cardiac tissue may be more susceptible to cell death via PFA than nerve tissue. Therefore, processing circuitry 551 may be configured to control delivery of PFA energy to the patient’s tissue to cause cell death in the cardiac tissue, but not in the vagus nerve. In some examples, delivery of the PFA energy may temporarily stun the vagus nerve. In some examples, delivery of the PFA energy may have no effect on the vagus nerve. However, delivery of the PFA energy may destroy the cardiac tissue surrounding electrode 516. Destruction of said cardiac tissue may prevent cardiac tissue from activating when AVN stimulation is thereafter provided to the vagus nerve. For example, processing circuitry 551 may be configured to control delivery of a pulse train of energy with particular voltages to the patient tissue. For example, processingcircuitry 551 may be configured to control delivery of a pulse train of energy with a voltage in the range of 400-1500 volts across patient tissue at the implantation site via electrode 516. In some examples, processing circuitry 551 may be configured to control delivery of a pulse train of energy with a voltage in the range of 300-4000 volts across patient tissue at the implantation site. In some examples, delivery of the PFA energy may temporarily stun the vagus nerve. However, delivery of the PFA energy may kill the cardiac tissue surrounding electrode 516. Destruction of said cardiac tissue may prevent the cardiac tissue from activating when AVN stimulation is thereafter provided to the vagus nerve.

[0093] Because delivery of PFA energy in general may destroy some of the cardiac tissue, there may be a risk that too much ablation of the cardiac tissue can impair normal operation of the heart. For example, electrical signals propagating through the cardiac tissue to cause normal heartbeat function may be interrupted or unevenly distributed through the cardiac tissue due to an area of destroyed cardiac tissue through which the electrical signals cannot propagate. Therefore, to increase safety for a patient, ablation device 501 may be configured to ablate as little of the cardiac tissue as possible. For example, electrode 516 may be configured to both deliver PFA energy and to provide electrical neuromodulation therapy (e.g., AVN stimulation). Electrode 516 may be maneuvered to the implantation site and affixed to patient tissue before delivering PFA energy. In this way, the PFA energy is delivered only to the specific implantation site to destroy the cardiac tissue only at the implantation site surrounding electrode 516 after implantation.

[0094] One aspect of this disclosure is an implantable medical lead that is configured deliver neuromodulation therapy as part of an acute or implanted system which is also capable of delivering PFA. In some cases, the lead may be bipolar or otherwise multipoloar and deliver neuromodulation and PFA via such a vector. The lead may be configured with higher current capacity than when a lead is strictly used for lower voltage stimulation therapies. Such configuration may include ufficient insulation between wires in the small lumen of a lead body to protect against the breakdown during delivery.

[0095] In some examples, rather than delivering both signals via the same lead, a secondary catheter may be used to ablate the area where a lead may be located from a procedural side. However, in examples where a first ablation lead ablates an area of patient tissue before a second therapy lead is implanted at the area, small discrepancies in the placement of the second lead may result in the second lead being affixed at a slightly different location from where ablation was applied to patient tissue. This can either defeat the purpose of the ablation, as the therapy lead may be close enough to non-ablated tissue to unintentionally activate the non-ablated tissue, or the first ablation lead may be used to ablate a large area of tissue to prevent unintentionalactivation of patient tissue via the misplaced therapy lead. Excess ablation of patient tissue is disadvantageous as discussed above.

[0096] Therefore examples according to this disclosure in which a single lead (e.g., lead 510) includes both ablation and therapy delivery electrodes (e.g., electrode 516) may: save time during an implantation procedure by removing the need for an additional lead; prevent excess harm to patient tissue by only ablating the necessary amount of tissue surrounding the implanted therapy electrode(s); and provide fewer instances of unintentional activation of patient tissue at the implantation site, as the therapy electrodes will be disposed at the same location where ablation was performed.

[0097] In some examples, in order to prevent excess ablation of patient tissue, the method may include measuring (e.g., via processing circuitry 550 and sensing circuitry 558 or processing circuitry 551 and sensing circuitry 559) an electrical response from patient tissue during an ablation procedure. For example, during the ablation procedure electrode 516 may deliver PFA energy using a defined pulse train with increasing voltage levels. In some examples, processing circuitry 551 may first control delivery of 400 volts across patient tissue at the implantation site, then measure an electrical response from one or more of the cardiac tissue and the vagus nerve sensed by sensing circuitry 559. Sensing circuitry 559 may sense the electrical response via electrode 516. Processing circuitry 551 may be configured to iteratively increase the voltage of the PFA energy delivered until the electrical response satisfies a threshold. For example, sensing circuitry 559 may measure an electrical response from patient tissue between each delivery of PFA energy until the electrical response reaches the desired level. In this way, no more PFA energy is applied to patient tissue than necessary to achieve a desired level of ablation and tissue response.

[0098] In some examples, the method includes measuring (e.g., via sensing circuitry 559 or sensing circuitry 558) an electrical response from nerve tissue (e.g., the vagus nerve) of the patient before lead 510 (and electrode 516) is affixed at the implantation site. For example, sensing circuitry 558 or processing circuitry 559 may measure an electrically evoked compound action potential (ECAP) of the vagus nerve to determine if placement of distal portion of lead 510 in patient tissue will provide effective therapy to the vagus nerve. Processing circuitry 550 or processing circuitry 551 may first electrically stimulate the vagus nerve via electrode 516, and sensing circuitry 558 or sensing circuitry 559 may thereafter measure the ECAP response. If the ECAP response satisfies a threshold, distal portion of lead 510 may be affixed at that location.

[0099] FIGS. 7 A and 7B are graphs illustrating the voltage of atrioventricular nodal stimulation required to achieve neuromodulation before and after ablation, respectively. 7Ashows delivery of therapy to the target site before ablation is performed with the lead. The even spacing of the deliveries is an effective slowing of the desired physiological response. After ablation is performed, the same level of therapy is applied (left side of 7B), and it is only after the therapy level is increased slightly to 2.5V that the same desirable slowed physiologic response is achieved. Significantly, the level needed to apply therapy increases substantially less than the increase in therapy level needed to induce AF or other undesired activation of cardiac tissue. Accordingly, there is an increased safety margin between effective therapy and undesired AF induction (or other negative effect depending on the target). Further, this increase in threshold for the nerve may further be a transient effect, meaning the increase while small, may also be negligible or even zero chronically.

[0100] The following examples are illustrative of the techniques described herein.

[0101] Example 1. A medical device comprising: an elongated structure configured to be navigated to an implantation site within a patient; at least one electrode carried on a distal portion of the elongated structure; and processing circuitry, wherein the processing circuitry is configured to cause the at least one electrode, when proximate to the implantation site, to: deliver PFA energy to ablate a first type of tissue at the implantation site; and provide electrical neuromodulation therapy to a second type of tissue at the implantation site.

[0102] Example 2. The medical device of example 1 , wherein the at least one electrode is further configured to be oriented relative to a heart of the patient, and wherein the processing circuitry is configured to cause the at least one electrode to deliver the PFA energy to cardiac tissue of the patient.

[0103] Example 3. The medical device of example 1 or 2, wherein the at least one electrode is further configured to be oriented relative to a heart of the patient, and wherein the processing circuitry is configured to cause the at least one electrode to provide electrical stimulation therapy to a vagus nerve of the patient.

[0104] Example 4. The medical device of any one or more of examples 1 to 3, wherein the elongated structure comprises an implantable medical lead.

[0105] Example 5. The medical device of any one or more of examples 1 to 4, wherein the PFA energy increases a difference between a first amount of energy required to provide the electrical neuromodulation therapy to the second type of tissue and a second amount of energy required to activate the first type of tissue at the implantation site.

[0106] Example 6. The medical device of any one or more of examples 1 to 5, wherein the PFA energy is configured to ablate the first type of tissue and not to ablate the second type of tissue.

[0107] Example 7. The medical device of any one or more of examples 1 to 6, wherein the processing circuitry is configured to cause the at least one electrode to deliver the PFA energy in a unipolar configuration.

[0108] Example 8. The medical device of any one or more of examples 1 to 6, wherein the at least one electrode comprises at least two electrodes, and wherein the processing circuitry is configured to cause the at least two electrodes to deliver the PFA energy in a bipolar configuration.

[0109] Example 9. The medical device of any one or more of examples 1 to 6, wherein the at least one electrode comprises: a first set of one or more electrodes; and a second set of one or more electrodes, wherein the second set of one or more electrodes is separate from the first set of one or more electrodes, wherein the processing circuitry is configured to cause the first set of one or more electrodes to deliver the PFA energy; and wherein the processing circuitry is configured to cause the second set of one or more electrodes to provide the electrical neuromodulation therapy.

[0110] Example 10. The medical device of any one or more of examples 1 to 9, wherein to deliver the PFA energy, the processing circuitry is configured to cause the at least one electrode to apply 300-4000 volts across the first type of tissue at the implantation site.

[0111] Example 11. A medical system comprising: an introducer defining a lumen; an implantable medical lead configured to be navigated to an implantation site within a patient using the introducer, wherein the lumen is sized to allow insertion of the implantable medical lead into the introducer; at least one electrode carried on a distal portion of the elongated structure; and processing circuitry, wherein the processing circuitry is configured to cause the at least one electrode, when proximate to the implantation site, to: deliver PFA energy to ablate a first type of tissue at the implantation site; and provide electrical neuromodulation therapy to a second type of tissue at the implantation site.

[0112] Example 12. The medical system of example 11, wherein the introducer defines at least one slot that exposes the at least one electrode of the implantable medical lead when the at least one electrode is proximate to the implantation site and oriented relative to target tissue of the patient.

[0113] Example 13. The medical system of example 11 or 12, wherein the at least one electrode is further configured to be oriented relative to a heart of the patient, and wherein the processing circuitry is configured to cause the at least one electrode to deliver the PFA energy to cardiac tissue of the patient.

[0114] Example 14. The medical system of any one or more of examples 11 to 13, wherein the at least one electrode is further configured to be oriented relative to a heart of the patient, and wherein the processing circuitry is configured to cause the at least one electrode to provide electrical stimulation therapy to a vagus nerve of the patient.

[0115] Example 15. The medical system of any one or more of examples 11 to 14, wherein the PFA energy increases a difference between a first amount of energy required to provide the electrical neuromodulation therapy to the second type of tissue and a second amount of energy required to activate the first type of tissue at the implantation site.

[0116] Example 16. The medical system of any one or more of examples 11 to 15, wherein the PFA energy is configured to ablate the first type of tissue and not to ablate the second type of tissue.

[0117] Example 17. The medical system of any one or more of examples 11 to 16, wherein the processing circuitry is configured to cause the at least one electrode to deliver the PFA energy in a unipolar configuration.

[0118] Example 18. The medical system of any one or more of examples 11 to 16, wherein the at least one electrode comprises at least two electrodes, and wherein the processing circuitry is configured to cause the at least two electrodes to deliver the PFA energy in a bipolar configuration.

[0119] Example 19. The medical system of any one or more of examples 11 to 16, further comprising a second electrode carried on a distal portion of the introducer, wherein the at least one electrode and the second electrode are configured to act as poles for delivery of the PFA energy, and wherein the processing circuitry is configured to cause the at least one electrode and the second electrode to deliver the PFA energy in a bipolar configuration.

[0120] Example 20. The medical device of any one or more of examples 11 to 16, wherein the at least one electrode comprises: a first set of one or more electrodes; and a second set of one or more electrodes, wherein the second set of one or more electrodes is separate from the first set of one or more electrodes, wherein the processing circuitry is configured to cause the first set of one or more electrodes to deliver the PFA energy; and wherein the processing circuitry is configured to cause the second set of one or more electrodes to provide the electrical neuromodulation therapy.

[0121] Example 21. The medical device of any one or more of examples 11 to 20, wherein to deliver the PFA energy, the processing circuitry is configured to cause the at least one electrode to apply 300-4000 volts across the first type of tissue at the implantation site.

[0122] Example 22. A method comprising: navigating an elongated structure to an implantation site within a patient, wherein the elongated structure carries at least one electrode on a distal portion of the elongated structure, and wherein navigating the elongated structure comprises navigating the at least one electrode to a position proximate to the implantation site; delivering, via the at least one electrode, PFA energy to ablate a first type of tissue at the implantation site; and providing, via the at least one electrode, electrical neuromodulation therapy to a second type of tissue at the implantation site.

[0123] Example 23. The method of example 22, further comprising: measuring an electrical response from the first type of tissue and / or the second type of tissue; and iteratively increasing the PFA energy delivered until the electrical response satisfies a threshold.

[0124] Example 24. The method of example 22 or 23, further comprising orienting the at least one electrode relative to a heart of the patient, and wherein the first type of tissue is cardiac tissue of the patient.

[0125] Example 25. The method of any one or more of examples 22 to 24, further comprising orienting the at least one electrode relative to a heart of the patient, and wherein the second type of tissue is a vagus nerve of the patient.

[0126] Example 26. The method of any one or more of examples 22 to 25, wherein the elongated structure comprises an implantable medical lead.

[0127] Example 27. The method of any one or more of examples 22 to 26, wherein the PFA energy increases a difference between a first amount of energy required to provide the electrical neuromodulation therapy to the second type of tissue and a second amount of energy required to activate the first type of tissue at the implantation site.

[0128] Example 28. The method of any one or more of examples 22 to 27, wherein the PFA energy is configured to ablate the first type of tissue and not to ablate the second type of tissue.

[0129] Example 29. The method of any one or more of examples 22 to 28, further comprising delivering the PFA energy via the at least one electrode in a unipolar configuration.

[0130] Example 30. The method of any one or more of examples 22 to 28, wherein the at least one electrode comprises at least two electrodes, and wherein the method further comprises delivering the PFA energy in a bipolar configuration.

[0131] Example 31. The method of any one or more of examples 22 to 28, wherein the at least one electrode comprises: a first set of one or more electrodes; and a second set of one or more electrodes, wherein the second set of one or more electrodes is separate from the first set of one or more electrodes, wherein the method further comprises: delivering, via the first set of oneor more electrodes the PFA energy; and providing, via the second set of one or more electrodes, the electrical neuromodulation therapy.

[0132] Example 32. The method of any one or more of examples 22 to 31 , wherein delivering the PFA energy comprises applying 300-4000 volts across the first type of tissue at the implantation site.

[0133] Various aspects of the disclosure have been described. These and other aspects are within the scope of the following claims.

Claims

CLAIMSWHAT IS CLAIMED IS:

1. A medical device comprising:an elongated structure configured to be navigated to an implantation site within a patient; at least one electrode carried on a distal portion of the elongated structure; and processing circuitry, wherein the processing circuitry is configured to cause the at least one electrode, when proximate to the implantation site, to:deliver PFA energy to ablate a first type of tissue at the implantation site; and provide electrical neuromodulation therapy to a second type of tissue at the implantation site.

2. The medical device of claim 1, wherein the at least one electrode is further configured to be oriented relative to a heart of the patient, and wherein the processing circuitry is configured to cause the at least one electrode to deliver the PFA energy to cardiac tissue of the patient.

3. The medical device of claim 1 or 2, wherein the at least one electrode is further configured to be oriented relative to a heart of the patient, and wherein the processing circuitry is configured to cause the at least one electrode to provide electrical stimulation therapy to a vagus nerve of the patient.

4. The medical device of any one or more of claims 1 to 3, wherein the elongated structure comprises an implantable medical lead.

5. The medical device of any one or more of claims 1 to 4, wherein the PFA energy increases a difference between a first amount of energy required to provide the electrical neuromodulation therapy to the second type of tissue and a second amount of energy required to activate the first type of tissue at the implantation site.

6. The medical device of any one or more of claims 1 to 5, wherein the PFA energy is configured to ablate the first type of tissue and not to ablate the second type of tissue.

7. The medical device of any one or more of claims 1 to 6, wherein the processing circuitry is configured to cause the at least one electrode to deliver the PFA energy in a unipolar configuration.

8. The medical device of any one or more of claims 1 to 6, wherein the at least one electrode comprises at least two electrodes, and wherein the processing circuitry is configured to cause the at least two electrodes to deliver the PFA energy in a bipolar configuration.

9. The medical device of any one or more of claims 1 to 6, wherein the at least one electrode comprises:a first set of one or more electrodes; anda second set of one or more electrodes, wherein the second set of one or more electrodes is separate from the first set of one or more electrodes,wherein the processing circuitry is configured to cause the first set of one or more electrodes to deliver the PFA energy; andwherein the processing circuitry is configured to cause the second set of one or more electrodes to provide the electrical neuromodulation therapy.

10. The medical device of any one or more of claims 1 to 9, wherein to deliver the PFA energy, the processing circuitry is configured to cause the at least one electrode to apply 300-4000 volts across the first type of tissue at the implantation site.

11. A medical system comprising:an introducer defining a lumen;an implantable medical lead configured to be navigated to an implantation site within a patient using the introducer, wherein the lumen is sized to allow insertion of the implantable medical lead into the introducer;at least one electrode carried on a distal portion of the elongated structure; and processing circuitry, wherein the processing circuitry is configured to cause the at least one electrode, when proximate to the implantation site, to:deliver PFA energy to ablate a first type of tissue at the implantation site; and provide electrical neuromodulation therapy to a second type of tissue at the implantation site.

12. The medical system of claim 11, wherein the introducer defines at least one slot that exposes the at least one electrode of the implantable medical lead when the at least one electrode is proximate to the implantation site and oriented relative to target tissue of the patient.

13. The medical system of claim 11 or 12, wherein the at least one electrode is further configured to be oriented relative to a heart of the patient, and wherein the processing circuitry is configured to:cause the at least one electrode to deliver the PFA energy to cardiac tissue of the patient; andcause the at least one electrode to provide electrical stimulation therapy to a vagus nerve of the patient.

14. The medical system of any one or more of claims 11 to 13, wherein the PFA energy increases a difference between a first amount of energy required to provide the electrical neuromodulation therapy to the second type of tissue and a second amount of energy required to activate the first type of tissue at the implantation site.

15. The medical system of any one or more of claims 11 to 14, wherein the PFA energy is configured to ablate the first type of tissue and not to ablate the second type of tissue.

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