Anodal stimulation-based conduction system pacing lead movement detection and alert

Abstract

A system includes a medical device including therapy delivery circuitry configured to deliver conduction system pacing to a heart of a patient via a first one or more of a plurality of electrodes disposed on an implantable medical lead coupled to the medical device and deliver anodal stimulation pacing via a second one or more of the plurality of electrodes disposed on the implantable medical lead; and sensing circuitry configured to sense one or more cardiac electrograms (EGMs) of the patient responsive to the delivery of the anodal stimulation pacing; and processing circuitry configured to: control the delivery of the anodal stimulation pacing by the therapy delivery circuitry on a periodic schedule; determine the implantable medical lead has migrated based on the one or more cardiac EGMs; and output an alert indicating the implantable medical lead has migrated to a user.

Description

ANODAL STIMULATION-BASED CONDUCTION SYSTEM PACING LEAD MOVEMENT DETECTION AND ALERT

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 678,138, filed August 1, 2024, which is entitled, “ANODAL STIMULATION-BASED CONDUCTION SYSTEM PACING LEAD MOVEMENT DETECTION AND ALERT” and is hereby incorporated by reference in its entirety.FIELD

[0002] This disclosure generally relates to medical devices and, more particularly, to cardiac therapy delivery by implantable medical devices.BACKGROUND

[0003] Some types of implantable medical devices, such as cardiac pacemakers or implantable cardioverter defibrillators, provide electrical therapy to a heart of a patient via electrodes of one or more implantable leads. The electrical therapy may be delivered to the heart in the form of pulses or shocks for pacing, cardioversion or defibrillation. In some cases, an implantable medical device may sense intrinsic depolarizations of the heart and control the delivery of electrical therapy to the heart based on the sensing.

[0004] Cardiac resynchronization therapy (CRT) is one type of electrical therapy delivered by an implantable medical device. Cardiac resynchronization therapy may help enhance cardiac output by resynchronizing the electromechanical activity of the ventricles of the heart and between one or more atria of the heart and the ventricles of the heart.Ventricular dyssynchrony may occur in patients that suffer from congestive heart failure (CHF). Atrioventricular dyssynchrony may occur when contraction of one or more ventricles of the heart are not properly synchronized with contractions of one or more atria of the heart. Implantable medical device systems that deliver CRT often include three leads to respectively place electrodes in or near the right atrium, right ventricle, and left ventricle, for separate pacing and / or sensing in each of these chambers.

[0005] Conduction system pacing (CSP) is a technology that uses the heart’s native conduction system to provide paced depolarizations and resulting contractions that better mimic intrinsic depolarizations and contractions, which may improve the health and pumping efficiency of the heart. Example types of conduction system pacing include His bundlepacing, left bundle branch area pacing (LBBAP), right bundle branch area pacing (RBBAP), and ventricular pacing from the atrium (VfA).SUMMARY

[0006] In general, this disclosure describes techniques for monitoring for lead migration in an implantable medical device (IMD) system configured to provide conduction system pacing (CSP) to a patient. If the lead is placed into a cardiac septum such that a ring electrode of the lead is in contact with a septum of a heart of the patient, the IMD system may be able to achieve anodal stimulation (i.e., capture at a ring electrode of the lead). This disclosure describes techniques for longitudinally monitoring for lead migration based on the ability of the system to achieve anodal stimulation changes.

[0007] CSP may provide cardiac resynchronization that is comparable to traditional technologies for providing CRT. CSP may have benefits over traditional technologies for providing CRT because CSP may be able to take advantage of synchronous depolarization from the heart’s native conduction system and may utilize fewer leads and / or deliver pulses to fewer cardiac chambers per cardiac cycle. Use of the techniques described in this disclosure may allow a user to ensure that the system delivering CSP is maintaining an expected quality of capture and / or to facilitate remedial action in cases of decreasing capture quality and / or loss of capture.

[0008] In one example, a system includes: a medical device comprising: therapy delivery circuitry configured to deliver conduction system pacing to a heart of a patient via a first one or more of a plurality of electrodes disposed on an implantable medical lead coupled to the medical device and deliver anodal stimulation pacing via a second one or more of the plurality of electrodes disposed on the implantable medical lead; and sensing circuitry configured to sense one or more cardiac electrograms (EGMs) of the patient responsive to the delivery of the anodal stimulation pacing; and processing circuitry configured to: control the delivery of the anodal stimulation pacing by the therapy delivery circuitry on a periodic schedule; determine the implantable medical lead has migrated based on the one or more cardiac EGMs; and output an alert indicating the implantable medical lead has migrated to a user.

[0009] In another example, a method includes: controlling, by therapy delivery circuitry of a medical device of a system, delivery of anodal stimulation pacing on a periodic schedule, wherein the therapy delivery circuitry is configured to deliver conduction system pacing to a heart of a patient via one or more of a plurality of electrodes disposed on an implantablemedical lead coupled to the medical device and deliver the anodal stimulation pacing via one or more of the plurality of electrodes disposed on the implantable medical lead; sensing, by sensing circuitry of a medical device of a system, one or more cardiac EGMs of the patient responsive to the delivery of the anodal stimulation pacing; determining, by processing circuitry of the medical device, the implantable medical lead has migrated based on the one or more cardiac EGMs; and outputting, by the processing circuitry, an alert indicating the implantable medical lead has migrated to a user.

[0010] In another example, a non-transitory computer-readable medium stores instructions that when executed cause processing circuitry to: control delivery of anodal stimulation pacing by therapy delivery circuitry of a medical device of a system on a periodic schedule, wherein the therapy delivery circuitry is configured to deliver conduction system pacing to a heart of a patient via a first one or more of a plurality of electrodes disposed on an implantable medical lead coupled to the medical device and deliver the anodal stimulation pacing via a second one or more of the plurality of electrodes disposed on the implantable medical lead; determine an implantable medical lead coupled to a medical device of a system has migrated based on one or more cardiac EGMs, wherein sensing circuitry of the medical device is configured to sense the one or more cardiac EGMs of a patient responsive to the delivery of the anodal stimulation pacing; and output an alert indicating the implantable medical lead has migrated to a user.

[0011] In another example, a system includes: a medical device comprising: therapy delivery circuitry configured to deliver conduction system pacing to a heart of a patient via a first one or more of a plurality of electrodes disposed on an implantable medical lead coupled to the medical device and deliver anodal stimulation pacing via a second one or more of the plurality of electrodes disposed on the implantable medical lead; and sensing circuitry configured to sense one or more cardiac electrograms (EGMs) of the patient responsive to the delivery of the anodal stimulation; and processing circuitry configured to: during an implantation procedure, control therapy delivery circuitry to deliver anodal stimulation pacing; determine whether anodal capture is present based on the one or more cardiac EGMs sensed by the sensing circuitry responsive to the anodal stimulation during the implantation procedure; determine a location of the implantable medical lead based on the determination; and output an indication of the location of the implantable medical lead.

[0012] In another example, a method includes: delivering, during an implantation procedure and by therapy delivery circuitry of a medical device system, the therapy delivery circuitry being configured to deliver conduction system pacing to a heart of a patient via afirst one or more of a plurality of electrodes disposed on an implantable medical lead coupled to the medical device and deliver anodal stimulation pacing via a second one or more of the plurality of electrodes disposed on the implantable medical lead, anodal stimulation pacing to the heart of the patient; sensing, by sensing circuitry of the medical device system, one or more cardiac electrograms (EGMs) of the patient responsive to delivery of anodal stimulation during the implantation procedure; determining, by processing circuitry of the medical device system, whether anodal capture is present based on the one or more cardiac EGMs sensed by the sensing circuitry responsive to the anodal stimulation during the implantation procedure; determining, by the processing circuitry, a location of the implantable medical lead based on the determination; and outputting, by the processing circuitry, an indication of the location of the implantable medical lead.

[0013] This summary is intended to provide an overview of the subject matter described in this disclosure. It is not intended to provide an exclusive or exhaustive explanation of the apparatus and methods described in detail within the accompanying drawings and description below. Further details of one or more examples are set forth in the accompanying drawings and the description below.BRIEF DESCRIPTION OF DRAWINGS

[0014] FIG. l is a conceptual diagram illustrating an example implantable medical device (IMD) system, in accordance with one or more techniques of this disclosure.

[0015] FIG. 2 is a block diagram illustrating an example system configured to longitudinally monitor for anodal capture in a patient, in accordance with one or more techniques of this disclosure.

[0016] FIG. 3 is a block diagram of an example configuration of an IMD, in accordance with one or more techniques of this disclosure.

[0017] FIG. 4 is a block diagram of an example configuration of an external device that operates in accordance with one or more techniques of this disclosure.

[0018] FIG. 5 is a flow diagram illustrating an example operation for determining a lead of the IMD system has migrated, in accordance with one or more techniques of this disclosure.

[0019] FIG. 6 is a graph illustrating cardiac electrogram and electrocardiogram signals, in accordance with one or more techniques of this disclosure.

[0020] FIG. 7 is a flow diagram illustrating an example operation for determining whether an IMD system can achieve anodal capture during an initialization phase, in accordance with one or more techniques of this disclosure.

[0021] FIG. 8 is a flow diagram illustrating an example operation for outputting a location of the lead of the IMD system to a user, in accordance with one or more techniques of this disclosure.

[0022] FIG. 9 is a flow diagram illustrating an example operation for determining whether the IMD system achieved anodal capture during an implantation procedure, in accordance with one or more techniques of this disclosure.

[0023] FIG. 10 is a flow diagram illustrating an example operation for determining the lead of the IMD system has migrated based on a score based on the cardiac EGM meeting a threshold, in accordance with one or more techniques of this disclosure.

[0024] Like reference characters refer to like elements throughout the figures and description.DETAILED DESCRIPTION

[0025] In general, this disclosure describes example techniques for longitudinally monitoring for migration of a lead of an implantable medical device (IMD) system configured for delivering conduction system pacing (CSP). Conduction system pacing is a technique in which one or more pacemaker devices use the heart’s native electrical conduction system to conduct electrical signals that cause depolarization of heart muscles, which ultimately causes synchronous contraction of the ventricles. Implantable medical device systems that perform conduction system pacing should generate electrical impulses based on a timing regime so that the patient’s heart achieves atrioventricular (AV) synchrony and interventricular synchrony.

[0026] CSP comprises pacing techniques that target specific portions of the natural conduction system of the heart. By targeting specific portions of the natural conduction system, CSP is associated with achieving more physiological pacing and better overall performance relative to other pacing techniques. The conduction system is a relatively small target. Over time, the lead of a CSP device can migrate, e.g., migrate within the septum or migrate out of the septum, which can cause issues with quality of capture, i.e., the ability to improve ventricular synchrony, and may even cause complete loss of capture. This disclosure describes techniques for detecting lead migration based on one or more cardiac EGMs sensed during anodal stimulation. A ring electrode configured for anodal stimulation may be one ofthe first components of the lead to leave the septum if the lead migrates. If the system detects a change in anodal capture while pacing with intentional anodal stimulation, e.g., pacing from the ring electrode to a case electrode or from a tip electrode to a ring electrode at a relatively high amplitude, e.g., between 1 V and 5 V, the system may determine the lead has migrated, e.g., partially migrated, out of the septum. Since the ring electrode will move with the lead and may be one of the first components to leave the septum if the lead migrates, the techniques of this disclosure may facilitate relatively quick identification of lead migration, which may improve patient outcomes.

[0027] This disclosure describes techniques for monitoring for changes in anodal capture over time on a periodic schedule based on one or more signals, e.g., one or more cardiac EGMs. In some examples, by monitoring for changes in anodal capture over time on the periodic schedule, the system may identify small changes in lead position over time. Some current systems are configured to identify complete loss of capture and do not detect small changes in lead position. In some examples, by identifying small changes in lead position, the techniques of this disclosure may facilitate identification of lead migration before complete loss of capture, which may improve patient outcomes. For example, by identifying lead migration before complete loss of capture, the techniques of this disclosure may allow the lead to be repositioned more easily. Additionally, patients may feel more at ease due to the relatively frequent checks to ensure the lead has not migrated.

[0028] In some examples, the system may determine lead migration based on one or more of a cardiac EGM, an electrocardiogram (ECG), or an impedance signal, e.g., an impedance signal of a ring electrode of the lead, corresponding to the anodal stimulation. As an example, the system may identify a change in a cardiac EGM from a baseline or template cardiac EGM. In some examples, the baseline or template cardiac EGM is based on one or more previous cardiac EGMs sensed during anodal stimulation.

[0029] In some examples, the system may determine whether anodal capture is present during an initialization phase. The initialization phase may be an implantation phase, e.g., during an implantation of a lead of the system or shortly thereafter, e.g., 30 to 60 days thereafter, or the initialization phase may correspond to any other time the system determines a placement of the implantable medical lead to determine whether to periodically apply anodal stimulation to monitor for lead migration. In some examples, the system may be configured to output an indication to a user of a location of the lead. As an example, based on whether anodal capture is present, the system may determine whether a portion of the lead, e.g., the ring electrode of the lead, is in contact with septal tissue of a heart of the patient. Ifthe ring electrode is in contact with the septal tissue, the system may determine the lead is placed appropriately. In some examples, based on the lead being placed appropriately and / or anodal capture being present, the system may determine to periodically deliver anodal stimulation to check for anodal capture to determine whether the lead has migrated. If the ring electrode is not in contact with the septal tissue, the system may determine the lead is not placed appropriately, e.g., the lead isn’t deep enough within a septum of the heart of the patient. In some examples, if the lead is not placed appropriately, the system may output instructions to adjust a position of the lead. In some examples, if the ring electrode remains inappropriately placed and / or anodal capture is not present, the system may determine not to periodically deliver anodal stimulation and check for anodal capture to determine whether the lead has migrated.

[0030] In some examples, in response to detecting the lead has migrated based on a detected change in anodal capture, the system may be configured to generate an alert to a user, e.g., the patient and / or a clinician. In some examples, the alert may include information indicating an extent to which the lead has migrated out of the septum. By alerting the user, the techniques of this disclosure may allow the user to take remedial action, which may improve patient outcomes.

[0031] FIG. l is a conceptual diagram illustrating a portion of an example implantable medical device (IMD) system 100 in accordance with one or more aspects of this disclosure. IMD system 100 may function as a dual-chamber pacemaker that delivers CSP to a heart 124 of patient 4.

[0032] In the example of FIG. 1, IMD system 100 includes implantable medical leads 104, 102 and an IMD 10. While two implantable medical leads are depicted in the example of FIG. 1, in other examples, system 100 may alternatively include a different number of implantable medical leads, such as one implantable medical lead. Implantable medical leads 104, 102 include elongated lead bodies 108, 106 with distal portions 112, 116, respectively. Distal portions 112, 116 of implantable medical leads 104, 102 are positioned at target sites 126, 122 within a heart 124 of a patient 4. Each of distal portions 112, 116 may include one or more electrodes.

[0033] Target site 126 may be located at an atrioventricular septal wall of a right atrium (RA) of heart 124. Target site 122 may be located at an interventricular septal wall of a right ventricle (RV) or left ventricle (LV) of heart 124. Each of leads 104, 102 may be a bipolar or multipolar lead.

[0034] A clinician may maneuver distal portions 112, 116 through the vasculature of patient 4 in order to position distal portions 112, 116 at or near target sites 126, 122. For example, the clinician may guide distal portion 112 through the superior vena cava (SVC) and into the RA, in order to access target site 126 on an atrioventricular septal wall 120 of heart 124, e.g., in the triangle of Koch region. The clinician may guide distal portion 116 through the SVC to target site 122 on or in a ventricular septal wall 120 of heart 124. In some examples, other pathways or techniques may be used to guide distal portions 112, 116 into other target implant sites within the body of patient 4. IMD system 100 may include a delivery catheter and / or outer member (not shown), and implantable medical leads 112, 113 may be guided and / or maneuvered within a lumen of the delivery catheter in order to approach target sites 126, 122.

[0035] In some examples, target site 126 may be the triangle of Koch region in the atrioventricular septal wall of the patient’s heart, and target site 122 may be the ventricular septal wall in the basal (e.g., high basal or high septal) region or apical (e.g., low septal or near the apex) region. Implantation in the triangle of Koch region of the atrioventricular septal wall may facilitate pacing of the His bundle or ventricular myocardium. Implantation in the basal region of the ventricular septal wall may facilitate pacing of the bundle of His or the left bundle branch. Implantation in the apical region may facilitate pacing of Purkinje fibers.

[0036] Implantable medical leads 104, 102 may include electrodes 114, 118 configured to penetrate cardiac tissue at or near target sites 126, 122, respectively. For example, electrodes 118 of implantable medical lead 102 may include a tip electrode be configured to penetrate to a position at or near the left bundle branch (LBB), His bundle (HB), right bundle branch (RBB), other specialized conductive tissue, or other ventricular tissue of heart 124 and a nontip or more proximal electrode, e.g., a ring electrode. In examples where the tip electrode of electrodes 118 is configured to penetrate to a position at or near the LBB or HB, electrode 118 may traverse the ventricular septum, i.e., septal wall 120, from right to left. The ring electrode, or other non-tip or more proximal electrode, of electrodes 118 may be in contact with septal tissue, which may result in anodal capture being possible. Although described as a ring electrode in examples of this disclosure, the non-tip or more proximal electrode may have a different shape. As examples, the non-tip or more proximal electrode may be a coil electrode, a pad electrode, a button electrode, or one or more segment electrodes. In some examples, electrodes 114, 118 are configured to function as electrodes in order to, for example, provide pacing to heart 124. Electrodes 114, 118 may be electrically connected toconductors (not shown) extending through implantable medical leads 104, 102 from electrodes 114, 118. In some examples, the conductors are electrically connected to therapy delivery circuitry of an IMD 10, with the therapy delivery circuitry configured to provide electrical signals through the conductor to electrodes 114, 118. Electrodes 114, 118 may conduct the electrical signals to the target tissue of heart 124, causing the cardiac muscle, e.g., of the ventricles, to depolarize and, in turn, contract at a regular interval. In examples in which one or more of electrodes 114, 118 penetrate to a position at or near the HB, RBB, LBB, or other specialized conductive tissue of heart 124, the cardiac pacing delivered via electrodes 114, 118 may be CSP of heart 122, which may provide more physiologic activation and contraction of heart 124. Electrodes 114, 118 may also be connected to sensing circuitry of IMD 10 via the conductor, and the sensing circuitry may sense activity of heart 124 via electrode 114. Electrodes 114, 118 may have various shapes such as tines, helices, screws, rings, and so on.

[0037] In some examples, tip electrodes of electrodes 114, 118 are configured to be extendable and / or retractable with respect to lead bodies 108, 106, in order to facilitate penetration of the cardiac tissue in the vicinity of target sites 126, 122. Lead bodies 108, 106 may allow tip electrodes of electrodes 114, 118 to be placed deeper into the tissue and to provide multiple electrodes at different locations. The extension and / or retraction of tip electrodes of electrodes 114, 118 may be controlled by a clinician. Although shown and described as being performed by IMD 10, in some examples, another medical device capable of being electrically connected to implantable medical leads 104, 102 during implantation, such as a pacing system analyzer, may be configured to take electrical measurements during penetration of electrodes 114, 118 into the cardiac tissue in order to, for example, determine suitable locations within the cardiac tissue for CSP of heart 124 and / or to determine whether to periodically deliver anodal stimulation to monitor for lead migration.

[0038] In the example of FIG. 1, IMD system 100 may administer cardiac pacing to a native conduction system (e.g., at least one of the HB, LBB, or RBB) of heart 124 of patient 4. In some instances, the native conduction system may be referred to as the “His-Purkinje conduction system” or “His-Purkinje system” which generally includes the HB, RBB, LBB and the Purkinje fibers. The adaptive optimized pacing provided by IMD system 100 may equal or exceed the clinical efficiency of conventional cardiac resynchronization therapy, but only uses two leads. In some examples, an IMD system provides conduction system pacing as described herein using a single lead placed in the right atrium and including electrodes configured to pacing and sense the right atrium and the left ventricle or other ventricularconduction system components discussed above, e.g., ventricle from atrium (VfromA) pacing. Furthermore, although described primarily in the context of examples in an IMD and intravascular leads, one or more transcatheter pacing devices may be additionally or alternatively used in some examples.

[0039] In some examples, IMD 10 may be in wireless communication with an external device 12. External device 12 may be a computing device with a display viewable by the user and an interface for providing input to external device 12 (i.e., a user input mechanism). External device 12 is configured for wireless communication with IMD 10. External device 12 retrieves sensed physiological data, e.g., cardiac electrogram (EGM) data, from IMD 10 that was collected and stored by IMD 10. In some examples, external device 12 takes the form of a personal computing device of the user, e.g., patient 4 or the clinician. For example, external device 12 may take the form of a smartphone of patient 4. In some examples, external device 12 may be any computing device configured for wireless communication with IMD 10, such as a desktop, laptop, or tablet computer. External device 12 may communicate with IMD 10 via near-field communication technologies e.g., inductive coupling, NFC or other communication technologies operable at ranges less than 10-20 cm, and far-field communication technologies, e.g., radiofrequency telemetry according to the Bluetooth® or Bluetooth® Low Energy (BLE) protocols, or other communication technologies operable at ranges greater than near-field communication technologies. When external device 12 is configured for use by the clinician, external device 12 may be used to transmit instructions to IMD 10. The clinician may also configure and store operational parameters for IMD 10 with the aid of external device 12.

[0040] External device 12 may be used to retrieve data from IMD 10. The retrieved data may include values of patient parameters measured by IMD 10 based on signals sensed by IMD 10. For example, external device 12 may retrieve physiological signal data, e.g., cardiac EGM data.

[0041] FIG. 2 is a block diagram illustrating an example system that includes an access point 210, a network 220, external computing devices, such as server 230, and one or more other computing devices 240A-240N, which may be coupled to IMD 10, and external device 12 via network 220, in accordance with one or more techniques described herein. IMD 10 may communicate with external device 12 via a first wireless connection and may communicate with an access point 210 via a second wireless connection. In the example of FIG. 2, access point 220, external device 12, server 230, and computing devices 240A-240N are interconnected and may communicate with each other through network 220.

[0042] Access point 210 may include a device that connects to network 220 via any of a variety of connections, such as telephone dial-up, digital subscriber line (DSL), or cable modem connections. In other examples, access point 210 may be coupled to network 220 through different forms of connections, including wired or wireless connections. In some examples, access point 90 may be a user device, such as a tablet or smartphone, that may be co-located with the patient. As discussed above, IMD 10 may be configured to transmit physiological data to external device 12. In addition, access point 210 may interrogate IMD 10, such as periodically or in response to a command from the patient or network 220, in order to retrieve patient data from IMD 10. Access point 210 may be communicate the retrieved data to server 230 via network 220.

[0043] In some cases, server 230 may be configured to provide a secure storage site for data that has been collected from IMD 10, and / or external device 12. In some cases, server 230 may assemble data for viewing by clinicians via computing devices 240A-240N. One or more aspects of the illustrated system of FIG. 2 may be implemented with general network technology and functionality, which may be similar to that provided by the Medtronic CareLink™ Network developed by Medtronic, Inc.

[0044] Server 230 may include processing circuitry 234. Processing circuitry 234 may include fixed function circuitry and / or programmable processing circuitry. Processing circuitry 234 may include any one or more of a microprocessor, a controller, digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), graphics processing unit (GPU), tensor processing unit (TPU), or equivalent discrete or analog logic circuitry. In some examples, processing circuitry 234 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 FGPAs, one or more GPUs, one or more TPUs, as well as other discrete of integrated logic circuitry. The functions attributed to processing circuitry 234 may be embodied as software, firmware, hardware, or any combination thereof. In some examples, processing circuitry 234 may perform one or more techniques described herein to monitor for lead migration based on a cardiac EGM signal received from IMD 10 and collected during anodal stimulation and / or to alert a user of the lead migration.

[0045] Server 230 may include storage device 232. Storage device 232 includes computer-readable instructions that, when executed by processing circuitry 234, cause IMD 10 and processing circuitry 234 to perform various functions attributed to IMD 10 and processing circuitry 234 herein. Storage device 232 may include any volatile, non-volatile,magnetic, optical, or electrical media, such as random access memory (RAM), read only memory (ROM), non-volatile RAM (NVRAM), electronically erasable programmable ROM (EEPROM), flash memory, or any other digital media.

[0046] In some examples, one or more of computing devices 240A-240N (collectively, “computing devices 240”), e.g., computing device 240A, may be a tablet or other smart device located with a clinician, by which the clinician may program, receive alerts from, and / or interrogate IMD 10. For example, the clinician may access data corresponding to the cardiac EGM signal and, in some examples, an impedance signal corresponding to the ring electrode, or lead migration information determined by IMD 10 based on the cardiac EGM signal, through device 240A, such as when patient 4 is in between clinician visits, to monitor for changes in anodal capture indicative of lead migration. In some examples, the clinician may enter instructions for medical intervention for patient 4 into an application in computing device 240 A, such as based on a status of a patient condition determined by IMD 10, external device 12, or the combination thereof, or based on other patient data known to the clinician. Computing device 240A may then transmit the instructions for medical intervention to another of computing devices 240, e.g., computing device 240B, located with patient 4 or a caregiver of patient 4. For example, such instructions for medical intervention may include an instruction to schedule a visit with the clinician or to seek medical attention. In this manner, patient 4 may be empowered to take action, as needed, to address his or her medical status, which may help improve clinical outcomes for patient 4.

[0047] FIG. 3 is a block diagram of an example configuration of IMD 10, in accordance with one or more techniques of this disclosure. IMD 10 is an example of a medical device that may be connected to implantable medical lead(s), but other medical devices, e.g., an external pacing system analyzer, may similarly be connected to implantable medical lead(s) and perform techniques of this disclosure. In examples in which IMD system 100 includes an external pacing system analyzer, the external pacing system analyzer may be configured substantially similarly to IMD 10.

[0048] In the illustrated example, IMD 10 includes memory 314, processing circuitry 302, sensing circuitry 304, therapy delivery circuitry 306, communication circuitry 318, and power source 310, one or more of which may be disposed within a housing of IMD 10. Power source 310 provides operational power for processing circuitry 302, sensing circuitry 304, sensor(s) 312, communication circuitry 318, memory 314, and therapy delivery circuitry 306.

[0049] In the example of FIG. 3, IMD 10 may also include one or more sensor(s) 312. In some examples, memory 314 includes computer-readable instructions that, when executed by processing circuitry 302, cause IMD 10 and processing circuitry 302 to perform various functions attributed to IMD 10 and processing circuitry 302 herein. Memory 314 may include any volatile, non-volatile, magnetic, optical, or electrical media, such as a random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically-erasable programmable ROM (EEPROM), flash memory, or any other digital media.

[0050] Processing circuitry 302 may include one or more of a microprocessor, a controller, digital signal processing circuitry (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or equivalent discrete or integrated logic circuitry. In some examples, processing circuitry 302 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 or integrated logic circuitry. The functions attributed to processing circuitry 302 herein may be implemented as software, firmware, hardware or any combination thereof. Processing circuitry 302 may control therapy delivery circuitry 306 to deliver pacing to a native conduction system of heart 124.

[0051] In some examples, processing circuitry 302 may control therapy delivery circuitry 306 to deliver unipolar pacing to a native conduction system of heart 124, and, on a periodic schedule, may control therapy delivery circuitry 306 to deliver relatively higher amplitude bipolar pacing, e.g., configured to result in anodal stimulation pacing, to the native conduction system of heart 124. In some examples, typical left bundle branch area pacing (LBBAP) may be effective at less than or around 1 Volt (V), and therapy delivery circuitry 306 may be configured to deliver up to 2 V during LBBAP to ensure capture. Therapy delivery circuitry 306 may deliver the relatively higher amplitude bipolar pacing between 1 V and 5 V or at a higher voltage, e.g., 10 V. In some examples, the relatively higher amplitude bipolar pacing may be around double a cathodal stimulation pacing threshold. The relative higher amplitude bipolar pacing may be below a typical shock pacing voltage, e.g., 600 V to 700 V. Sensing circuitry 304 may sense one or more signals, e.g., cardiac EGMs, during the unipolar pacing and / or during the anodal stimulation pacing. Based on the one or more cardiac EGMs corresponding to the anodal stimulation pacing, processing circuitry 302 may determine whether the implantable medical lead has migrated. For example, processing circuitry 302 may compare the one or more cardiac EGMs corresponding to the anodal stimulation pacing to the one or more cardiac EGMs corresponding to the unipolar pacing.Based on the comparison, processing circuitry 302 determines whether anodal capture has changed and / or whether anodal capture is lost. Based on the determination, processing circuitry 302 determines whether the implantable medical lead has migrated.

[0052] Sensing circuitry 304 is configured to monitor signals from at least one of electrodes 316 in order to monitor activity of heart 124, e.g., via cardiac EGM signals, ECG signals, and / or impedance signals. Electrodes 316 may correspond to electrodes on one or more of leads 104, 102 and / or one or more electrodes on a housing of IMD 10. In some examples, sensing circuitry 304 includes switching circuitry (not depicted) to select which of the available electrodes are used to sense the activity of heart 124. For example, processing circuitry 302 may select the electrodes that function as sense electrodes via the switching circuitry within sensing circuitry 304, e.g., by providing signals via a data / address bus. In some examples, sensing circuitry 304 includes one or more sensing channels, each of which may comprise an amplifier. In response to the signals from processing circuitry 302, the switching circuitry of sensing circuitry 304 may couple the outputs from the selected electrodes to one of the sensing channels.

[0053] Sensing circuitry 304 may include impedance sensing circuitry 320. Impedance sensing circuitry 320 may receive signals from one or more of electrodes 316 indicative of an impedance signal. In some examples, the impedance signal may be sensed by at least a ring electrode of electrodes 316 on one of leads 104, 102.

[0054] Signals from the sensing electrodes may be converted to multi-bit digital signals by an analog-to-digital converter for storage in memory 314. Processing circuitry 302 may employ digital signal analysis techniques to characterize the digitized signals stored in memory 314 to detect and classify the patient's heart rhythm from the signals. Processing circuitry 302 may detect and classify the heart rhythm of patient 4 by employing any of the numerous signal processing methodologies known in the art.

[0055] In some examples, IMD 10 may include one or more additional sensor(s) 312, such as accelerometers. In some examples, accelerometers may comprise one or more three-axis accelerometers. Processing circuitry 302 may determine patient parameter values based on the signals obtained therefrom. Furthermore, in some examples, processing circuitry 302 may use signals generated by accelerometers to sense specific cardiac events, such as atrial or ventricular contractions.

[0056] In the example of FIG. 3, therapy delivery circuitry 306 is electrically coupled to electrodes 316. Electrodes 114, 118 (FIG. 1) may include one or more of electrodes 316. Therapy delivery circuitry 306 is configured to administer cardiac pacing. For example,therapy delivery circuitry 306 may deliver a pacing stimulus to a native conduction system of heart 124 and thereby administer cardiac pacing.

[0057] Therapy delivery circuitry 306 may include switching circuitry. Processing circuitry 302 may use the switching circuitry to select, e.g., via a data / address bus, which of the available electrodes are used to deliver pacing pulses. The switching circuitry may include a switch array, switch matrix, multiplexer, or any other type of switching device suitable to selectively couple energy to selected electrodes. In other examples, processing circuitry 302 may select a subset of electrodes 316 with which energy is delivered to heart 124 without a switching circuitry.

[0058] In some examples, processing circuitry 302 may store data in memory 314. The diagnostic data may include one or more of cardiac EGMs corresponding to the periodic anodal stimulation, impedances corresponding to the periodic anodal stimulation, or ECGs corresponding to the periodic anodal stimulation.

[0059] In some examples, during cardiac pacing, processing circuitry 302 may determine pace timing by mechanical assessment of cardiac activation. For instance, IMD system 100 may include one or more transcatheter pacing devices, which may also be referred to as transcatheter pacemakers, intracardiac pacemakers, or leadless pacemakers. An example type of transcatheter pacing device is a Mi era ™ device from Medtronic, Inc of Minneapolis, Minnesota.

[0060] Communication circuitry 318 may include any suitable hardware, firmware, software, or any combination thereof for communicating with another device, such as external device 12, another networked computing device, or another IMD or sensor. Under the control of processing circuitry 302, communication circuitry 318 may receive downlink telemetry from, as well as send uplink telemetry to external device 12. In addition, processing circuitry 302 may communicate with a networked computing device via an external device (e.g., external device 12) and a computer network, such as the Medtronic CareLink™ Network. Communication circuitry 318 may be configured to transmit and / or receive signals via inductive coupling, electromagnetic coupling, Near Field Communication (NFC), Radio Frequency (RF) communication, Bluetooth, Wi-Fi, or other proprietary or nonproprietary wireless communication schemes.FIG. 4 is a block diagram of an example configuration of external device 12 that operates in accordance with one or more techniques of this disclosure. External device 12 is configured to communicate with any IMD (e.g., IMD 10) described herein, in accordance with one or more techniques of this disclosure. In theexample of FIG. 4, external device 12 includes processing circuitry 406, communication circuitry 408, user interface 404, power source 402, and memory 410.

[0061] Processing circuitry 406, in one example, may include one or more processors that are configured to implement functionality and / or process instructions for execution within external device 600. For example, processing circuitry 406 may be capable of processing instructions stored in memory 410. Processing circuitry 406 may include, for example, microprocessors, DSPs, ASICs, FPGAs, GPUs, TPUs, or equivalent discrete or integrated logic circuitry, or a combination of any of the foregoing devices or circuitry. Accordingly, processing circuitry 406 may include any suitable structure, whether in hardware, software, firmware, or any combination thereof, to perform the functions ascribed herein to processing circuitry 406.

[0062] Communication circuitry 408 may include any suitable hardware, firmware, software or any combination thereof for communicating with another device, such as IMD 10. Under the control of processing circuitry 406, communication circuitry 408 may receive downlink telemetry from, as well as send uplink telemetry to, IMD 10, or another device.

[0063] A user, such as a clinician or patient 4, may interact with external device 12 through user interface 404. User interface 404 includes a display (not shown), such as an LCD or LED display or other type of screen, with which processing circuitry 406 may present information related to IMD 10 (e.g., a detection of lead migration). In addition, user interface 404 may include an input mechanism to receive input from the user. The input mechanisms may include, for example, any one or more of buttons, a keypad (e.g., an alphanumeric keypad), a peripheral pointing device, a touch screen, or another input mechanism that allows the user to navigate through user interfaces presented by processing circuitry 406 of external device 12 and provide input. In other examples, user interface 404 also includes audio circuitry for providing audible notifications, instructions or other sounds to patient 4, receiving voice commands from patient 4, or both. Memory 410 may include instructions for operating user interface 404 and for managing power source 608.

[0064] Processing circuitry 302 of IMD 10 may control communication circuitry 304 to transmit information, e.g., the one or more cardiac EGMs, ECG(s), impedance data, lead migration information, anodal capture information, and / or alert information, to external device 12. In some examples, processing circuitry 406 determines whether to display an alert based on the transmitted information. In some examples, processing circuitry 406 determines the lead migration information and / or anodal capture information. As an example, when the transmitted information includes the cardiac EGM(s), ECG(s), and / or impedance data,processing circuitry 406 may determination lead migration information and / or anodal capture information. Processing circuitry 406 may control user interface 404 to display an alert corresponding to the lead migration and / or anodal capture information to the user.

[0065] In some examples, external device 12 may be a patient device, e.g., a smartphone of patient 4. In some examples, external device 12 may be a programming device of the clinician. As an example, during an implantation procedure, processing circuitry 302 and / or processing circuitry 406 may determine whether a placement of the implantable medical lead(s) results in anodal capture. User interface 404 may display information indicative of the implantable medical lead(s) placement and may instruct the clinician to reposition the implantable medical lead(s).

[0066] Power source 402 is configured to deliver operating power to the components of external device 12. Power source 402 may include a battery and a power generation circuit to produce the operating power. In some examples, the battery is rechargeable to allow extended operation. Recharging may be accomplished by electrically coupling power source 402 to a cradle or plug that is connected to an alternating current (AC) outlet. In addition, recharging may be accomplished through proximal inductive interaction between an external charger and an inductive charging coil within external device 12. In other examples, traditional batteries (e.g., nickel cadmium or lithium ion batteries) may be used. In addition, external device 12 may be directly coupled to an alternating current outlet to operate.

[0067] Memory 410 may be configured to store information within external device 12 during operation. In some examples, memory 410 may be referred to as a storage device and include computer-readable instructions that, when executed by processing circuitry 406, cause external device 12 and processing circuitry 406 to perform various functions attributed to external device 12 and processing circuitry 406 herein. Memory 410 may include any volatile, non-volatile, magnetic, optical, or electrical media, such as RAM, DRAM, SRAM, magnetic discs, optical discs, flash memories, ROM, NVRAM, EPROM, EEPROM, flash memory, or any other digital media. Memory 410 may also store data generated by sensing circuitry 304 of IMD 10, such as signals corresponding to indications of lead migration.

[0068] FIG. 5 is a flow diagram illustrating an example operation for determining a lead of the IMD system 100 has migrated, in accordance with one or more techniques of this disclosure. The example of FIG. 5 will be described with respect to processing circuitry 302 of IMD 10, but other processing circuitry, e.g., processing circuitry 406 of external device 12 and / or other devices or systems may be used in other examples. In some examples,processing circuitry of different devices may be used to collectively perform this technique in a distributed computing model.

[0069] Processing circuitry 302 controls therapy delivery circuitry, e.g., therapy delivery circuitry 306, to deliver anodal stimulation pacing to a heart of a patient, e.g., heart 124 patient 4, on a periodic schedule via one or more of a plurality of electrodes, e.g., a ring electrode of electrodes 114, 118, disposed on an implantable medical lead, e.g., one of leads 104, 102 (502). The periodic schedule may correspond to delivering anodal stimulation pacing daily, weekly, or monthly, as examples. In some examples, based on a determination that the lead has migrated, processing circuitry 302 may update the periodic schedule. For example, if processing circuitry 302 determines the lead has migrated, processing circuitry may adjust the periodic schedule from weekly to daily. In some examples, therapy delivery circuitry 306 may be configured to normally deliver unipolar pacing and may switch to relatively high amplitude, e.g., between 1 V and 5 V, bipolar pacing to check for lead migration on the periodic schedule. For examples, therapy delivery circuitry 306 may deliver unipolar pacing to a patient and periodically provide high amplitude bipolar pacing to provide anodal stimulation pacing. In some examples, therapy delivery circuitry 306 may be configured to normally deliver bipolar pacing and may switch to relatively high amplitude bipolar pacing to check for lead migration on the periodic schedule. In some examples, processing circuitry 302 may determine to check for lead migration by controlling therapy delivery circuitry 306 to deliver bipolar pacing in response to determining a change in a morphology of one or more cardiac EGMs. Processing circuitry 302 may be configured to differentiate between morphology changes caused by lead migration and other causes, e.g. drug administration, electrolyte disturbances, and changes in disease state.

[0070] Sensing circuitry 304 senses one or more cardiac EGMs of patient 4 during the anodal stimulation pacing (504). In some examples, the one or more cardiac EGMs comprises a cardiac EGM sensed via a tip electrode and ring electrode. In some examples, the one or more cardiac EGMs additionally or alternatively comprises one or more cardiac EGMs sensed via one or more of a tip electrode and a can electrode or a ring electrode and a can, e.g., housing, electrode. In some examples, sensing circuitry 304 additionally senses an ECG of patient 4. As an example, IMD 10 may be in wireless communication with two or more external electrodes configured to sense an ECG of patient 4. In some examples, impedance sensing circuitry 320 of sensing circuitry 304 senses an impedance signal of patient 4.

[0071] Processing circuitry 302 determines whether the implantable medical lead has migrated based on the one or more cardiac EGMs (506). In examples in which sensingcircuitry 304 additionally senses an ECG and / or an impedance signal, processing circuitry 302 may determine whether the implantable medical lead has migrated based on the one or more cardiac EGMs and the ECG and / or the impedance signal. If processing circuitry 302 determines the implantable medical lead has migrated, processing circuitry 302 generates for output an alert indicating the implantable medical lead has migrated to a user, e.g., patient 4 or a clinician (508). In some examples, to output the alert, processing circuitry 302 controls communication circuitry 318 to transmit the generated alert, the determination that the lead has migrated, and / or the one or more cardiac EGMs to external device 12. In some examples, user interface 404 of external device 12 is configured to display the alert.

[0072] FIG. 6 is a graph illustrating cardiac EGM and ECG signals, in accordance with one or more techniques of this disclosure. Cardiac EGMs 622 and ECG signals 620 correspond to signals sensed during unipolar pacing, and cardiac EGMs 608 and ECG signals 606 correspond to signals sensed during bipolar pacing. In some examples, to determine whether anodal capture is present, processing circuitry 302 may be configured to compare a unipolar paced cardiac EGM, e.g., cardiac EGM 610 of cardiac EGMs 622, to a bipolar, anodal stimulation paced cardiac EGM, e.g., cardiac EGM 612 of cardiac EGMs 608 sensed by sensing circuitry 304. In some examples, positive deflection 614 may be indicative of anodal capture. Cardiac EGMs 610 and 612 may be sensed by sensing circuitry via vector from tip electrode to ring electrode of one of leads 102, 104 or a ring electrode of one of leads 102, 104 to a housing, i.e., can or case, electrode of IMD 10. In some examples, lead 102 may be configured for LBBAP.

[0073] In some examples, IMD system 100 may be programmed to deliver unipolar pacing to patient 4. Processing circuitry 302 may determine to switch to delivering relatively higher amplitude bipolar pacing to patient 4 on the periodic schedule to monitor for changes in anodal capture. After monitoring for the change in anodal capture by delivering high amplitude bipolar pacing, e.g., anodal stimulation, processing circuitry 302 may switch back to delivering unipolar pacing. In some examples, IMD system 100 may be programmed to delivery bipolar pacing at a first amplitude to patient 4. Processing circuitry 302 may determine to increase the bipolar pacing amplitude from the first pacing amplitude to a second pacing amplitude, e.g., higher amplitude bipolar pacing, on the periodic schedule to monitor for changes in anodal capture. After monitoring for the change in anodal capture, processing circuitry 302 may decrease the bipolar pacing amplitude from the high amplitude bipolar pacing to the first bipolar pacing amplitude.

[0074] Processing circuitry 302 may determine whether anodal capture is present and / or whether anodal capture has changed based on the comparison between cardiac EGMs 610 in 612. In some examples, processing circuitry 302 may compare additional cardiac EGMs. As an example, processing circuitry 302 may compare cardiac EGM 616 of cardiac EGMs 622 to cardiac EGM 618 of bipolar cardiac EGMs 608, which may correspond to tip electrode to ring electrode EGMs of lead 104. In some examples, the bipolar cardiac EGMs 608 may additionally or alternatively correspond to a ring electrode to can electrode EGM. In some examples, lead 104 may be configured to RV pacing. In some examples, cardiac EGMs 608 and cardiac EGMs 622 may additionally include one or more of a tip electrode to can electrode EGM or a ring electrode to can electrode EGM (not depicted).

[0075] In some examples, sensing circuitry 304 may additionally sense ECGs 606. Processing circuitry 302 may compare one or more of ECG signals 606 to one or more corresponding signals of ECG signals 620 to determine whether anodal capture is present. As shown in FIG. 6, each of ECG signals 606, e.g., the ECG signals corresponding to high amplitude bipolar pacing, e.g., anodal stimulation pacing, undergo morphological changes compared to the respective ECG signals of ECG signals 620. Processing circuitry 302 may compare one or more of the ECG signals 606 to one or more of the ECG signals 620 by comparing one or more morphology features.

[0076] In some examples, cardiac EGMs 622 and ECG signals 620 include waveforms that are patient specific. For example, cardiac EGMs 622 and ECG signals 620, which are associated with conduction system pacing, e.g., unipolar pacing, and to which the waveforms associated with anodal stimulation, e.g., cardiac EGMs 608 and ECG signals 606, are compared, may comprise a patient specific template. In some examples, cardiac EGMs 622 comprises average cardiac EGM waveforms and ECG signals 620 comprises average ECG waveforms of a plurality of previous cardiac EGM and ECG waveforms sensed during unipolar pacing to the heart 124 of patient 4. Processing circuitry 302 may update the waveforms of cardiac EGMs 622 and ECG signals 620 continuously over time, or cardiac EGMs 622 and ECG signals 620 may be based on waveforms corresponding to a time of implantation or shortly after implantation, e.g., within 30 to 60 days of implantation, and may not be updated. In some examples, cardiac EGMs 622 and ECG signals 620 include waveforms that are not patient specific. For example, cardiac EGMs 622 and ECG signals 620 may include average expected waveforms based on waveforms of a plurality of patients.

[0077] Processing circuitry 302 may compare one or more cardiac EGMs of cardiac EGMs 608 to one or more cardiac EGMs of cardiac EGMs 622. In some examples, tocompare the cardiac EGM(s) corresponding to high amplitude bipolar pacing, i.e., cardiac EGMs 608, to the cardiac EGM(s) corresponding to unipolar pacing, i.e., cardiac EGMs 622, processing circuitry 302 may determine a similarity value. If the similarity value exceeds a threshold, processing circuitry 302 may determine anodal capture is not present or has changed. If the similarity value is less than the threshold, processing circuitry 302 may determine anodal capture is present or has not changed.

[0078] In some examples, processing circuitry 302 may be configured to determine whether to periodically control therapy delivery circuitry 306 to deliver anodal stimulation pacing, e.g., high amplitude bipolar pacing, by delivering anodal stimulation pacing (e.g., high amplitude bipolar pacing) and unipolar pacing to patient 4 during an initialization phase, e.g., during an implantation phase, such as during an implantation procedure or shortly thereafter, e.g., within 60 days of implantation, or any other time processing circuitry 302 determines to determine whether to periodically control therapy delivery circuitry 306 to deliver anodal stimulation pacing. Sensing circuitry 304 may sense one or more cardiac EGMs and ECGs corresponding to the anodal stimulation pacing and one or more cardiac EGMs and ECGs corresponding to the unipolar stimulation pacing. Processing circuitry 302 may compare the cardiac EGM(s) 608 and ECG signals 606 corresponding to the anodal stimulation pacing to the cardiac EGM(s) 622 and ECGs 620 corresponding to the unipolar stimulation pacing. If processing circuitry 302 determines anodal capture is present, processing circuitry 302 may determine to periodically check for anodal capture to monitor for lead migration. If processing circuitry 302 determines anodal capture is not present, processing circuitry 302 may determine to output instructions to adjust a placement of the implantable medical lead or may determine not to periodically check for anodal capture.

[0079] FIG. 7 is a flow diagram illustrating an example operation for determining whether IMD system 100 can achieve anodal capture during an initialization phase, in accordance with one or more techniques of this disclosure. The example of FIG. 7 will be described with respect to processing circuitry 302 of IMD 10, but other processing circuitry, e.g., processing circuitry 406 of external device 12 and / or other devices or systems may be used in other examples. In some examples, processing circuitry of different devices may be used to collectively perform this technique in a distributed computing model. For example, an external pacing system analyzer may be connected to the implantable medical lead(s) and may perform the techniques described herein in whole or in part.

[0080] During an initialization phase, e.g., during an implantation phase, such as during implantation of the implantable medical lead(s) and / or within a period of time, e.g., 30 days,after implantation, processing circuitry 302 may control therapy delivery circuitry 306 to deliver anodal stimulation pacing via one or more of a plurality of electrodes disposed on the implantable medical lead, e.g., electrodes 114, 118 of leads 104, 102 (702). Sensing circuitry 304 may sense one or more cardiac EGMs corresponding to the anodal stimulation. Based on the one or more cardiac EGMs, processing circuitry 302 determines whether anodal capture is present (704). If anodal capture is present (“YES” of 704), processing circuitry 302 determines to deliver anodal stimulation pacing on a periodic schedule to check for migration of the implantable medical lead after implantation (706). If anodal capture is not present (“NO” of 704), processing circuitry 302 determines not to deliver anodal stimulation pacing on the periodic schedule (708). In some examples, before determining not to deliver anodal stimulation pacing on the periodic schedule, processing circuitry may control communication circuitry 304 to output instructions to adjust a placement of the implantable medical lead and may deliver anodal stimulation pacing again to check for anodal capture of the repositioned implantable medical lead.

[0081] FIG. 8 is a flow diagram illustrating an example operation for outputting a location of the lead of the IMD system to a user, in accordance with one or more techniques of this disclosure. The example of FIG. 8 will be described with respect to processing circuitry 302 of IMD 10, but other processing circuitry, e.g., processing circuitry 406 of external device 12 and / or other devices or systems may be used in other examples. In some examples, processing circuitry of different devices may be used to collectively perform this technique in a distributed computing model. For example, an external pacing system analyzer may be connected to the implantable medical lead(s) and may perform the techniques described herein in whole or in part.

[0082] During implantation of implantable medical leads 104, 102, processing circuitry 302 controls therapy delivery circuitry 306 to deliver anodal stimulation pacing (802). Sensing circuitry 304 senses one or more cardiac EGMs of heart 124 of patient 4 during anodal stimulation (804). In some examples, sensing circuitry 304 additionally or alternatively senses one or more of an ECG of heart 124 and / or an impedance signal of heart 124. Based on the one or more cardiac EGMs, processing circuitry 302 determines whether anodal capture is present (806). In some examples, to determine whether anodal capture is present, processing circuitry 302 compares the one or more EGMs corresponding to the delivered anodal stimulation pacing to one or more EGMs corresponding to unipolar pacing.

[0083] In some examples, comparing the one or more EGMs corresponding to the delivered anodal stimulation pacing to the one or more EGMs corresponding to the unipolarpacing comprises determining a similarity value. If the similarity value exceeds a similarity threshold, processing circuitry 302 may determine anodal capture is not present. If the similarity value falls below the similarity threshold, processing circuitry 302 may determine anodal capture is present. Based on the determination, processing circuitry 302 determines a location of the implantable medical lead (808). In some examples, as part of determining the location of the implantable lead, processing circuitry 302 determines whether the implantable medical lead is placed appropriately. If the implantable medical lead is not placed appropriately, e.g., that the implantable medical lead is in sufficient contact with the septum of heart 124. In some examples, if the lead is not placed appropriately, anodal capture is not present. In some examples, an implantable medical lead is in sufficient contact with the septum when a ring electrode of the lead is in contact with septal tissue. If the similar value falls below the similarity threshold, processing circuitry 302 may determine the implantable medical lead is placed appropriately, e.g., that the ring electrode of the lead is in contact with septal tissue. In some examples, if the lead is placed appropriately, anodal capture is present.

[0084] Processing circuitry 302 controls communication circuitry 318 to transmit data indicative of the location of the implantable medical lead to, for example, external device 12. External device 12 may be a programming device or other computing device used by a clinician. Processing circuitry 406 of external device 12 may control user interface 404 to output an indication of the location of the implantable medical lead for user review, e.g., for clinician review (810). In some examples, the indication may comprise an image indicative of a location of the implantable medical lead. Additionally or alternatively, the indication may be text indicating to the clinician whether the lead is placed appropriately and / or whether anodal capture is present. In some examples, the indication may additionally or alternatively include an audible indication.

[0085] FIG. 9 is a flow diagram illustrating an example operation for determining whether IMD system 100 achieved anodal capture during an implantation procedure, in accordance with one or more techniques of this disclosure. In some examples, FIG. 9 may be a specific example of FIG. 8. The example of FIG. 9 will be described with respect to processing circuitry 302 of IMD 10, but other processing circuitry, e.g., processing circuitry 406 of external device 12 and / or other devices or systems may be used in other examples. In some examples, processing circuitry of different devices may be used to collectively perform this technique in a distributed computing model. For example, an external pacing system analyzer may be connected to the implantable medical lead(s) and may perform the techniques described herein in whole or in part.

[0086] During an implantation procedure, processing circuitry 302 controls therapy delivery circuitry 306 to deliver unipolar pacing, e.g., high output unipolar pacing (902). Sensing circuitry 304 senses a cardiac EGM and / or an ECG corresponding to the unipolar pacing (904). Optionally, sensing circuitry 304 additionally measures an impedance signal, e.g. determines an impedance based on a current signal sensed in response to an applied voltage, corresponding to the unipolar pacing, i.e., an impedance measurement between a tip electrode of leads 104, 102 and a housing electrode of IMD 10 (906). Processing circuitry 302 controls therapy delivery circuitry to deliver bipolar pacing, e.g., high output bipolar pacing, e.g., anodal stimulation pacing (908). Sensing circuitry 304 senses a cardiac EGM and / or an ECG corresponding to the bipolar pacing (910). Optionally, sensing circuitry 304 additionally measures an impedance signal corresponding to the bipolar pacing, i.e., an impedance between a ring electrode and a tip electrode of leads 104, 102 (912). Processing circuitry 302 compares the cardiac EGMs and / or the ECGs corresponding to the unipolar pacing and the bipolar pacing (914). In examples in which sensing circuitry senses the impedance signals corresponding to the unipolar pacing and the bipolar pacing, processing circuitry compares the impedance signals (916). Impedance signals may comprise a single impedance measurement or a plurality of impedance measurements over a period of time. Processing circuitry 302 determines whether the comparison(s) meet corresponding threshold(s) (918). If the comparison(s) meet the corresponding threshold(s) (“YES” of 918), processing circuitry 302 outputs to the user that anodal capture is present (920). If the comparison(s) do not meet the corresponding threshold(s) (“NO” of 918), processing circuitry 302 outputs to the user that anodal capture is not present (922). In some examples, to output to the user that anodal capture is or is not present, processing circuitry 302 may control communication circuitry 318 to transmit data to external device 12. User interface 404 may display the output that anodal capture is or is not present.

[0087] FIG. 10 is a flow diagram illustrating an example operation for determining the implantable medical lead of IMD system 100 has migrated based on a score based on the cardiac EGM meeting a threshold, in accordance with one or more techniques of this disclosure. The example of FIG. 9 will be described with respect to processing circuitry 302 of IMD 10, but other processing circuitry, e.g., processing circuitry 406 of external device 12 and / or other devices or systems may be used in other examples. In some examples, processing circuitry of different devices may be used to collectively perform this technique in a distributed computing model.

[0088] Processing circuitry 302 determines a score based on a tip electrode to ring electrode EGM corresponding to anodal stimulation, e.g., cardiac EGM 612 of FIG. 6 (1002). In some examples, the EGM corresponding to anodal stimulation may alternatively comprise a ring electrode to can electrode EGM. In some examples, the score is based on a comparison of the tip electrode to ring electrode EGM corresponding to the anodal stimulation to a template tip electrode to ring electrode EGM corresponding to unipolar stimulation, e.g., cardiac EGM 610 of FIG. 6. In some examples in which the template is patient specific, processing circuitry 302 updates the template continuously, e.g., on a periodic basis. In some examples, if the score meets a score threshold, processing circuitry 302 determines the implantable medical lead has migrated (1004). In some examples, the score updates continuously. For example, the score threshold may be a previous score, e.g., a score determined based on a previous cardiac EGM during a previous delivery of anodal stimulation. In some examples, the score threshold is a static value, and processing circuitry determines a difference between the difference between the score and the score threshold and the difference between the previous score and the score threshold.

[0089] Example 1. A system comprising: a medical device comprising: therapy delivery circuitry configured to deliver conduction system pacing to a heart of a patient via a first one or more of a plurality of electrodes, wherein at least one of the first one or more of the plurality of electrodes is disposed on an implantable medical lead coupled to the medical device, and deliver anodal stimulation pacing via a second one or more of the plurality of electrodes, wherein at least one of the second one or more of the plurality of electrodes is disposed on the implantable medical lead; and sensing circuitry configured to sense one or more cardiac electrograms (EGMs) of the patient responsive to the delivery of the anodal stimulation pacing; and processing circuitry configured to: control the delivery of the anodal stimulation pacing by the therapy delivery circuitry on a periodic schedule; determine the implantable medical lead has migrated based on the one or more cardiac EGMs; and output an alert indicating the implantable medical lead has migrated to a user.

[0090] Example 2. The system of example 1, wherein the processing circuitry is further configured to: during an initialization phase, control the therapy delivery circuitry to deliver anodal stimulation pacing via the one or more of the plurality of electrodes disposed on the implantable medical lead; determine anodal capture is present based on one or more cardiac EGMs sensed by sensing circuitry and responsive to the anodal stimulation pacing delivered during the initialization phase; and based on the determination that anodal captureis present during the initialization phase, determine to deliver anodal stimulation pacing on the periodic schedule.

[0091] Example 3. The system of example 2, wherein the initialization phase comprises an implantation phase, and wherein anodal capture is indicative of a placement of the implantable medical lead.

[0092] Example 4. The system of any of examples 2-3, wherein the processing circuitry is further configured to: generate, for output to a user, an indication of whether anodal capture is present based on the determination that anodal capture is present during the initialization phase.

[0093] Example 5. The system of example any of examples 1-4, wherein the processing circuitry is configured to determine the implantable medical lead has migrated based on at least a morphology of the one or more cardiac EGMs.

[0094] Example 6. The system of any of examples 1-5, wherein the sensing circuitry is configured to sense the one or more cardiac EGMs via a tip electrode and a ring electrode of the implantable medical lead.

[0095] Example 7. The system of example 6, wherein the sensing circuitry is configured to sense the one or more cardiac EGMs via one or more of a tip electrode and can electrode of the implantable medical lead or a ring electrode and can electrode of the implantable medical lead.

[0096] Example 8. The system of any of examples 6-7, wherein to determine the implantable medical lead has migrated based on the one or more cardiac EGMs, the processing circuitry is configured to at least: determine a score based on the cardiac EGM sensed via the tip electrode and ring electrode EGM or the ring electrode and can electrode EGM; and based on the score satisfying a threshold, determine the implantable medical lead has migrated.

[0097] Example 9. The system of example 8, wherein to determine the score, the processing circuitry is configured to compare a current beat of the cardiac EGM sensed via the tip electrode and ring electrode of the implantable medical lead to one or more of a previous paced beat of the cardiac EGM sensed via the tip electrode and ring electrode of the implantable medical lead or via the ring electrode and can electrode or a template.

[0098] Example 10. The system of example 9, wherein the template is patientspecific.

[0099] Example 11. The system of any of examples 1-10, wherein the conduction system pacing comprises left bundle branch area pacing (LBBAP).

[0100] Example 12. The system of any of examples 1-11, wherein to determine the lead has migrated, the processing circuitry is configured to determine the lead has migrated relative to a septum of the heart of the patient.

[0100] Example 13. The system of any of examples 1-12, wherein the processing circuitry comprises processing circuitry of the medical device.

[0101] Example 14. The system of any of examples 1-13, wherein the medical device comprises an implantable medical device.

[0102] Example 15. The system of any of examples 1-14, wherein the therapy delivery circuitry is configured to deliver the conduction system pacing at a first amplitude, and the anodal stimulation pacing at a second amplitude higher than the first amplitude.

[0103] Example 16. A method comprising: controlling, by therapy delivery circuitry of a medical device of a system, delivery of anodal stimulation pacing on a periodic schedule, wherein the therapy delivery circuitry is configured to deliver conduction system pacing to a heart of a patient via a first one or more of a plurality of electrodes, wherein at least one of the plurality of electrodes is disposed on an implantable medical lead coupled to the medical device, and deliver the anodal stimulation pacing via a second one or more of the plurality of electrodes, wherein at least one of the plurality of electrodes is disposed on the implantable medical lead; sensing, by sensing circuitry of a medical device of a system, one or more cardiac electrograms (EGMs) of the patient responsive to the delivery of the anodal stimulation pacing; determining, by processing circuitry of the medical device, the implantable medical lead has migrated based on the one or more cardiac EGMs; and outputting, by the processing circuitry, an alert indicating the implantable medical lead has migrated to a user.

[0104] Example 17. The method of example 16, further comprising: controlling, by the processing circuitry and during an initialization phase, the therapy delivery circuitry to deliver anodal stimulation pacing via the one or more of the plurality of electrodes disposed on the implantable medical lead; determining, by the processing circuitry, anodal capture is present based on one or more cardiac EGMs sensed by sensing circuitry and responsive to the anodal stimulation pacing delivered during the initialization phase; and determining, by the processing circuitry and based on the determination that anodal capture is present during the initialization phase, to deliver anodal stimulation pacing on the periodic schedule.

[0105] Example 18. The method of example 17, wherein the initialization phase comprises an implantation phase, and wherein anodal capture is indicative of a placement of the implantable medical lead.

[0106] Example 19. The system of any of examples 17-18, wherein the processing circuitry is further configured to: generate, for output to a user, an indication of whether anodal capture is present based on the determination that anodal capture is present during the initialization phase.

[0107] Example 20. The method of example any of examples 16-19, wherein determining the implantable medical lead has migrated comprises determining the medical lead has migrated based on at least a morphology of the one or more cardiac EGMs.

[0108] Example 21. The method of any of examples 16-20, wherein the sensing circuitry is configured to sense the one or more cardiac EGMs via a tip electrode and a ring electrode of the implantable medical lead.

[0109] Example 22. The method of example 21, wherein the sensing circuitry is further configured to sense the one or more EGMs via one or more of a tip electrode and a can electrode of the implantable medical lead or a ring electrode and a can electrode of the implantable medical lead.

[0110] Example 23. The method of any of examples 21-22, wherein determining the implantable medical lead has migrated based on the one or more cardiac EGMs comprises: determining, by the processing circuitry, a score based on the cardiac EGM sensed via the tip electrode and ring electrode or the ring electrode and can electrode; and determining, by the processing circuitry and based on the score satisfying a threshold, the implantable medical lead has migrated.

[0111] Example 24. The method of example 23, wherein determining the score comprises: comparing, by the processing circuitry, a current beat of the cardiac EGM sensed via the tip electrode and ring electrode or the ring electrode and can electrode to one or more of a previous paced beat of the cardiac EGM sensed via the tip electrode and ring electrode or via the ring electrode and can electrode or a template.

[0112] Example 25. The method of example 24, wherein the template is patient specific.

[0113] Example 26. The method of any of examples 16-25, wherein the conduction system pacing comprises left bundle branch area pacing (LBBAP).

[0114] Example 27. The method of any of examples 16-26, wherein determining the lead has migrated comprises determining the lead has migrated relative to a septum of the heart of the patient.

[0115] Example 28. The method of any of examples 16-27, wherein the processing circuitry comprises processing circuitry of the medical device.

[0116] Example 29. The method of any of examples 16-28, wherein the medical device comprises an implantable medical device.

[0117] Example 30. The method of any of examples 16-29, wherein the therapy delivery circuitry is configured to deliver the conduction system pacing at a first amplitude, and the anodal stimulation pacing at a second amplitude higher than the first amplitude.

[0118] Example 31. A non-transitory computer-readable medium storing instructions that when executed cause processing circuitry to: control delivery of anodal stimulation pacing by therapy delivery circuitry of a medical device of a system on a periodic schedule, wherein the therapy delivery circuitry is configured to deliver conduction system pacing to a heart of a patient via a first one or more of a plurality of electrodes, wherein at least one of the first one or more of the plurality of electrodes is disposed on an implantable medical lead coupled to the medical device, and deliver the anodal stimulation pacing via a second one or more of the plurality of electrodes, wherein at least one of the second one or more of the plurality of electrodes is disposed on the implantable medical lead; determine an implantable medical lead coupled to a medical device of a system has migrated based on one or more cardiac electrograms (EGMs), wherein sensing circuitry of the medical device is configured to sense the one or more cardiac EGMs of a patient responsive to the delivery of the anodal stimulation pacing; and output an alert indicating the implantable medical lead has migrated to a user.

[0119] Example 32. A system comprising: a medical device comprising: therapy delivery circuitry configured to deliver conduction system pacing to a heart of a patient via a first one or more of a plurality of electrodes, wherein at least one of the first one or more of the plurality of electrodes is disposed on an implantable medical lead coupled to the medical device, and deliver anodal stimulation pacing via a second one or more of the plurality of electrodes, wherein at least one of the second one or more of the plurality of electrodes is disposed on the implantable medical lead; and sensing circuitry configured to sense one or more cardiac electrograms (EGMs) of the patient responsive to the delivery of the anodal stimulation; and processing circuitry configured to: during an implantation procedure, control therapy delivery circuitry to deliver anodal stimulation pacing; determine whether anodal capture is present based on the one or more cardiac EGMs sensed by the sensing circuitry responsive to the anodal stimulation during the implantation procedure; determine a location of the implantable medical lead based on the determination; and output an indication of the location of the implantable medical lead.

[0120] Example 33. The system of example 31, wherein to determine the location of the implantable medical lead based on the determination, the processing circuitry is configured to: responsive to a determination that anodal capture is present, determine a ring electrode of the implantable medical lead is in contact with septal tissue of the heart of the patient; or responsive to a determination that anodal capture is not present, determine that the ring electrode of the implantable medical lead is not in contact with the septal tissue.

[0121] Example 34. A method comprising: delivering, during an implantation procedure and by therapy delivery circuitry of a medical device system, the therapy delivery circuitry being configured to deliver conduction system pacing to a heart of a patient via a first one or more of a plurality of electrodes, wherein at least one of the first one or more of the plurality of electrodes is disposed on an implantable medical lead coupled to the medical device, and deliver anodal stimulation pacing via a second one or more of the plurality of electrodes, wherein at least one of the second one or more of the plurality of electrodes is disposed on the implantable medical lead, anodal stimulation pacing to the heart of the patient; sensing, by sensing circuitry of the medical device system, one or more cardiac electrograms (EGMs) of the patient responsive to delivery of anodal stimulation during the implantation procedure; determining, by processing circuitry of the medical device system, whether anodal capture is present based on the one or more cardiac EGMs sensed by the sensing circuitry responsive to the anodal stimulation during the implantation procedure; determining, by the processing circuitry, a location of the implantable medical lead based on the determination; and outputting, by the processing circuitry, an indication of the location of the implantable medical lead.

[0122] Example 35. The system of example 34, wherein to determining the location of the implantable medical lead based on the determination comprises: determining, by the processing circuitry and responsive to a determination that anodal capture is present, a ring electrode of the implantable medical lead is in contact with septal tissue of the heart of the patient; or determining, by the processing circuitry and responsive to a determination that anodal capture is not present, the ring electrode of the implantable medical lead is not in contact with the septal tissue.

[0123] Various examples have been described. These and other examples are within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1. A system comprising: a medical device comprising: therapy delivery circuitry configured to deliver conduction system pacing to a heart of a patient via a first one or more of a plurality of electrodes, wherein at least one of the first one or more of the plurality of electrodes is disposed on an implantable medical lead coupled to the medical device, and deliver anodal stimulation pacing via a second one or more of the plurality of electrodes, wherein at least one of the second one or more of the plurality of electrodes is disposed on the implantable medical lead; and sensing circuitry configured to sense one or more cardiac electrograms (EGMs) of the patient responsive to the delivery of the anodal stimulation pacing; and processing circuitry configured to: control the delivery of the anodal stimulation pacing by the therapy delivery circuitry on a periodic schedule; determine the implantable medical lead has migrated based on the one or more cardiac EGMs; and output an alert indicating the implantable medical lead has migrated to a user.

2. The system of claim 1, wherein the processing circuitry is further configured to: during an initialization phase, control the therapy delivery circuitry to deliver anodal stimulation pacing via the one or more of the plurality of electrodes disposed on the implantable medical lead; determine anodal capture is present based on one or more cardiac EGMs sensed by sensing circuitry and responsive to the anodal stimulation pacing delivered during the initialization phase; and based on the determination that anodal capture is present during the initialization phase, determine to deliver anodal stimulation pacing on the periodic schedule.

3. The system of claim 2, wherein the initialization phase comprises an implantation phase, and wherein anodal capture is indicative of a placement of the implantable medical lead.

4. The system of any of claims 2-3, wherein the processing circuitry is further configured to: generate, for output to a user, an indication of whether anodal capture is present based on the determination that anodal capture is present during the initialization phase.

5. The system of claim any of claims 1-4, wherein the processing circuitry is configured to determine the implantable medical lead has migrated based on at least a morphology of the one or more cardiac EGMs.

6. The system of any of claims 1-5, wherein the sensing circuitry is configured to sense the one or more cardiac EGMs via a tip electrode and a ring electrode of the implantable medical lead.

7. The system of claim 6, wherein the sensing circuitry is configured to sense the one or more cardiac EGMs via one or more of a tip electrode and can electrode of the implantable medical lead or a ring electrode and can electrode of the implantable medical lead.

8. The system of any of claims 6-7, wherein to determine the implantable medical lead has migrated based on the one or more cardiac EGMs, the processing circuitry is configured to at least: determine a score based on the cardiac EGM sensed via the tip electrode and ring electrode EGM or the ring electrode and can electrode EGM; and based on the score satisfying a threshold, determine the implantable medical lead has migrated.

9. The system of claim 8, wherein to determine the score, the processing circuitry is configured to compare a current beat of the cardiac EGM sensed via the tip electrode and ring electrode of the implantable medical lead to one or more of a previous paced beat of the cardiac EGM sensed via the tip electrode and ring electrode of the implantable medical lead or via the ring electrode and can electrode or a template.

10. The system of claim 9, wherein the template is patient-specific.

11. The system of any of claims 1-10, wherein the conduction system pacing comprises left bundle branch area pacing (LBBAP).

12. The system of any of claims 1-11, wherein to determine the lead has migrated, the processing circuitry is configured to determine the lead has migrated relative to a septum of the heart of the patient.

13. The system of any of claims 1-12, wherein the processing circuitry comprises processing circuitry of the medical device.

14. The system of any of claims 1-13, wherein the medical device comprises an implantable medical device.

15. The system of any of claims 1-14, wherein the therapy delivery circuitry is configured to deliver the conduction system pacing at a first amplitude, and the anodal stimulation pacing at a second amplitude higher than the first amplitude.

Images