left posterior fascicular capture

Abstract

Systems and methods can monitor electrical activity of a patient's heart during delivery of a cardiac therapy using electrodes, and determine a degree of left posterior fascicle capture based on the monitored electrical activity. The systems and methods can adjust the cardiac therapy based on the degree of left posterior fascicle capture.

Description

[0001] This disclosure relates to systems and methods for determining left posterior bundle branch engagement via cardiac therapy.

[0002] Implantable medical devices (IMDs), such as implantable pacemakers, cardioverter-defibrillators, or pacemaker-cardioverter-defibrillators, deliver therapeutic electrical stimulation to the heart. IMDs can provide pacing to resolve bradycardia, or pacing or shock to terminate rapid arrhythmias such as tachycardia or fibrillation. In some cases, the device can sense the heart's inherent depolarization, detect arrhythmias based on (or the absence of) inherent depolarization, and, if an arrhythmia is detected based on inherent depolarization, control the delivery of electrical stimulation to the heart.

[0003] IMD can also offer cardiac resynchronization therapy (CRT), a form of pacing. CRT involves delivering pacing pulses to the left ventricle or both the left and right ventricles. The timing and location of the pacing pulses delivered to one or more ventricles can be selected to improve the coordination and efficiency of ventricular contractions.

[0004] In addition to the implantable medical device itself, the system used to implant the device may also include a workstation or other equipment. In some cases, these other devices assist physicians or other technicians in placing the intracardiac lead at a specific location on or within the heart. In other cases, the device provides the physician with information about the heart's electrical activity and the location of the intracardiac lead. Summary of the Invention

[0005] The illustrative systems and methods described herein can be configured to assist users (e.g., physicians) in assessing left posterior bundle branch engagement (e.g., whether the patient's left posterior bundle branch is engaged) in patients receiving cardiac therapies (e.g., cardiac conduction system pacing, conventional, non-conduction system pacing, etc.). More specifically, for example, the illustrative systems and methods can be used to determine the degree of left posterior bundle branch engagement based on monitored electrical activity. The monitored electrical activity can be used to generate or compute electrical heterogeneity information pointing to left posterior bundle branch engagement. Additionally, the illustrative systems and methods described herein can be configured to assist users (e.g., physicians) in adjusting cardiac therapy based on assessments of left posterior bundle branch engagement via cardiac therapy.

[0006] In one or more embodiments, the system and method may be described as non-invasive. For example, in some embodiments, the system and method may not require or include implantable devices such as leads, probes, sensors, catheters, implantable electrodes, etc., to monitor or acquire electrical activity (e.g., multiple cardiac signals) from the patient's tissues for assessing the patient's left posterior bundle branch access via cardiac therapy. Instead, the system and method may use the results of electrical measurements non-invasively performed using multiple external electrodes attached to the patient's skin, for example, around the patient's torso. In one or more embodiments, the system and method may be described as invasive because such systems and methods can utilize implantable electrodes to monitor electrical activity for assessing the patient's left posterior bundle branch access via cardiac therapy. Additionally, it should be understood that in some embodiments, both invasive and non-invasive devices and procedures may be used simultaneously.

[0007] It can be described that, when delivering cardiac therapies such as VfA pacing therapy, this disclosure provides qualitative and quantitative feedback regarding the engagement of the left posterior bundle. One of the goals of VfA pacing therapy may be to engage the left posterior bundle to rapidly propagate electrical activation. The illustrative systems and methods described herein may include electrode devices (e.g., “ECG bands”) that can be used as surface mapping tools to aid in visualizing electrical activation on a “body surface” activation map.

[0008] This disclosure provides various measures that reflect the degree of posterior fascicular engagement during cardiac therapies such as VfA pacing, left bundle branch (LBB) pacing, etc. Therefore, pacing electrode position, pacing thresholds for complete posterior fascicular engagement, and other pacing parameters (e.g., pacing vector, pacing amplitude, pacing pulse length, timing delays such as AV delay and VV delay) can be adjusted to achieve or provide “complete” or maximal engagement of the left posterior bundle from cardiac pacing therapy pacing (e.g., using leadless or leaded VfA pacing). These pacing thresholds and parameters may differ from those used for conventional myocardial tissue capture.

[0009] This disclosure describes systems and methods for providing more efficient resynchronization (e.g., using VfA pacing, LBB pacing, left ventricular septal basement pacing, etc.) based on the engagement of the posterior branch or posterior LBB, which, if successfully completed, should result in full preactivation of the posterior body surface as reflected on an alternative activation time map. Additionally, the novel metrics disclosed herein can be used and correlated with the concept of pacing titration to maximize the engagement of the left posterior bundle.

[0010] An illustrative measure of electrical heterogeneity information (EHI) can be the average activation time of posterior electrodes (e.g., a subset of electrodes placed at the back of the patient, such as near the posterior trunk), which may be referred to as the mean posterior activation time (MPAT). Another illustrative measure of EHI can be the percentage of posterior electrodes that are activated earlier than a specific time threshold (e.g., 35 milliseconds), which may be referred to as the percentage of early posterior activation (PEPA), indicating the extent of early activation spread in the posterior part of the body.

[0011] These illustrative measures of the EHI can be used to reflect the degree of posterior bundle engagement during cardiac therapies such as VfA pacing. For example, an MPAT of 30 ms or less and a PEPA of 75% or more reflect complete posterior bundle engagement. Additionally, an MPAT between 30 and 50 ms and a PEPA between 50% and 75% reflect intermediate posterior bundle engagement. Furthermore, any other values ​​of MPAT and PEPA may reflect insufficient posterior bundle engagement.

[0012] Illustrative systems and methods can utilize illustrative metrics of the EHI to adjust one or more cardiac therapy parameters (e.g., pacing parameters such as pacing output, pacing vector, pacing site, etc.). Thus, one or more cardiac therapy parameters can be “tuned” towards full posterior bundle engagement, indicated by lower MPAT values ​​and higher PEPA values. Additionally, cardiac therapy parameters can be set to maximize left posterior bundle engagement. Illustrative cardiac therapy systems or devices can store such cardiac therapy parameters in memory and accordingly set safety margins above a basic tissue capture threshold for the cardiac therapy thus delivered.

[0013] Additionally, illustrative systems and methods can qualitatively indicate the degree of engagement based on colors on the posterior plot, encoded by red shading for early activation and green / blue shading for late activation. A full red on the posterior plot of the band can signify full engagement. Less red on the posterior plot corresponds to lesser degree of posterior band engagement.

[0014] Successful resynchronization using, for example, VfA pacing can depend in part on the degree of engagement of the left posterior bundle, which leads to rapid propagation of activation in the posterior / posterior portion of the left ventricle. The illustrative systems and methods described herein provide a way to evaluate the degree of noninvasive engagement of the left posterior bundle with an electrode device, which can aid in the delivery of effective cardiac therapy.

[0015] An illustrative system may include an electrode device comprising a plurality of posterior electrodes for monitoring electrical activity from the posterior aspect of a patient; and a computing device comprising a processing circuitry system and coupled to the electrode device. The computing device may be configured to monitor the electrical activity of the patient's heart using the plurality of posterior electrodes during delivery of cardiac therapy, generate electrical heterogeneity information (EHI) based on the electrical activity monitored during delivery of cardiac therapy, and determine the degree of left posterior bundle branch engagement based on the generated EHI.

[0016] An illustrative method may include monitoring the electrical activity of a patient’s heart using multiple posterior electrodes from the back of the patient during delivery of cardiac therapy, generating electrical heterogeneity information (EHI) based on the electrical activity monitored during delivery of cardiac therapy, and determining the degree of left posterior bundle branch entrainment based on the generated EHI.

[0017] An illustrative system may include an electrode device comprising a plurality of posterior electrodes for monitoring electrical activity from the posterior portion of a patient; and a computing device comprising a processing circuitry system and coupled to the electrode device. The computing device is configured to monitor the electrical activity of the patient's heart using the plurality of posterior electrodes during delivery of cardiac pacing therapy, determine the degree of left posterior bundle branch engagement based on the monitored electrical activity, and adjust one or more pacing settings of the cardiac pacing therapy based on the determined degree of left bundle branch engagement.

[0018] The above overview is not intended to describe every embodiment or every implementation of this disclosure. A more complete understanding will become apparent and understood by taking into account the accompanying drawings and the following detailed description and claims. Attached Figure Description

[0019] Figure 1 It is a diagram of an illustrative system that includes electrode devices, display devices, and computing devices.

[0020] Figure 2-3 This is a diagram illustrating an external electrode device used to measure the surface potential of the torso.

[0021] Figure 4 A block diagram illustrating the assessment of the left posterior bundle branch via cardiac therapy and the adjustment of such cardiac therapy.

[0022] Figure 5A Illustrative anterior and posterior electrical activation diagrams depicting full left posterior bundle branch junction are provided.

[0023] Figure 5B Illustrative anterior and posterior electrical activation diagrams depicting the partial left posterior bundle branch junction are provided.

[0024] Figure 5C Illustrative anterior and posterior electrical activation diagrams depicting an insufficiently depicted left posterior bundle branch junction are presented.

[0025] Figure 6A Illustrative anterior and posterior electrical activation diagrams depicting the electrode representation and full left posterior bundle branch junction are provided.

[0026] Figure 6B Illustrative anterior and posterior electrical activation diagrams depicting the partial left posterior bundle branch junction, including electrode representations.

[0027] Figure 6C Illustrative anterior and posterior electrical activation diagrams depicting the electrode representation and the inadequate left posterior bundle branch junction are provided.

[0028] Figure 7 A conceptual diagram of an illustrative cardiac therapy system comprising an intracardiac medical device implanted in the patient's heart and a separate medical device positioned outside the patient's heart.

[0029] Figure 8 for Figure 7 An enlarged conceptual diagram of the anatomy of an intracardiac medical device and a patient's heart.

[0030] Figure 9 A conceptual diagram of a patient's heart in a standard 17-segment view of the left ventricle, showing various electrode implantation sites, for use with the illustrative systems and devices described herein.

[0031] Figure 10 For example, to be enclosed Figure 7-8 A block diagram of an illustrative circuit system within the housing of a medical device to provide the functions and therapies described herein. Detailed Implementation

[0032] In the following detailed description of illustrative embodiments, reference is made to the accompanying drawings, which form part of the specific embodiments and illustrate, by way of illustration, specific embodiments that can be practiced. It should be understood that other embodiments may be utilized and the scope of the structure may be changed without departing from (e.g., still falling within) the scope of this disclosure herein.

[0033] Reference Figure 1-10This description is intended to illustrate illustrative systems and methods. It will be apparent to those skilled in the art that elements or processes of one embodiment may be used in combination with elements or processes of other embodiments, and that possible embodiments of such systems, methods, and apparatuses using combinations of features set forth herein are not limited to the specific embodiments shown in the figures and / or described herein. Furthermore, it will be appreciated that the embodiments described herein may include many elements that are not necessarily shown to scale. Additionally, it will be appreciated that the timing of the processes and the sizes and shapes of the various elements herein may be modified but still fall within the scope of this disclosure, although certain timings, one or more shapes and / or sizes, or element types may be preferred over others.

[0034] Various illustrative systems, methods, and graphical user interfaces can be configured to noninvasively assist users (e.g., physicians) in the assessment of left posterior bundle branch engagement of cardiac therapy and / or the configuration (e.g., optimization) of assessment-based cardiac therapy using electrode devices, display devices, and computing devices that include external electrodes. Figure 1 The illustration depicts a system 100 including an electrode device 110, a computing device 140, and a remote computing device 160.

[0035] The electrode device 110 shown includes a plurality of electrodes incorporated or contained within a band wrapped around the chest or torso of a patient 114. The electrode device 110 is operatively coupled to a computing device 140 (e.g., via a wired or wireless connection) to provide electrical signals from each of the electrodes to the computing device 140 for analysis, evaluation, etc. An illustrative electrode device can be described in U.S. Patent No. 9,320,446, filed March 27, 2014 and published March 26, 2016, entitled “Bioelectric Sensor Device and Methods,” and further details of the illustrative electrode device 110 will be referenced elsewhere. Figure 2-3 To provide a more detailed description.

[0036] Computing device 140 and remote computing device 160 may each include display devices 130 and 170, respectively, which may be configured to display data, such as electrical signals (e.g., electrocardiogram data), electrical activation time, electrical heterogeneity information, etc. For example, one or more measures of a cardiac cycle or a single heartbeat represented by electrical signals collected or monitored by electrode device 110 may be analyzed and evaluated, the one or more measures including activation time and electrical heterogeneity information relevant to evaluation and assessment that can be associated with the left posterior bundle branch. More specifically, for example, one or more measures can be used to assess the QRS complex in a single cardiac cycle, such as QRS onset, QRS deviation, QRS peak, various electrical heterogeneity information (EHI) such as electrical activation time, standard deviation of left ventricular or thoracic electrical activation time (LVED), standard deviation of activation time (SDAT), mean left ventricular or thoracic substitution electrical activation time (LVAT) and reference earliest activation time, QRS duration (e.g., the interval between QRS onset and QRS deviation), the difference between mean left substitution and mean right substitution activation times, relative or absolute QRS morphology, the difference between higher and lower percentiles of activation time (higher percentiles may be 90%, 80%, 75%, 70%, etc. and lower percentiles may be 10%, 15%, 20%, 25%, and 30%, etc.), other statistical measures of central tendency (e.g., median or mode), deviations (e.g., mean deviation, standard deviation, variance, interquartile range), etc. Additionally, each of the one or more measures may be location-specific. For example, some metrics can be calculated based on signals recorded or monitored from electrodes positioned around selected areas of the patient (e.g., the patient's left side, the patient's right side, etc.).

[0037] In at least one embodiment, one or both of the computing device 140 and the remote computing device 160 may be a server, a personal computer, or a tablet computer. The computing device 140 may be configured to receive input from an input device 142 (e.g., a keyboard) and transmit output to a display device 130, and the remote computing device 160 may be configured to receive input from an input device 162 (e.g., a touchscreen) and transmit output to a display device 170. One or both of the computing device 140 and the remote computing device 160 may include a data storage device that allows access to a processor or routine and / or one or more other types of data, such as for analyzing multiple electrical signals captured by the electrode device 110, for determining EHI, for determining QRS start, QRS offset, median, mode, average, peak or maximum, trough or minimum, for determining electrical activation time, for evaluating left posterior bundle branch engagement via cardiac therapy, for determining whether a patient has left or right ventricular delay or block, and for determining cardiac... Whether one or more adjustments to the pacing settings of the visceral therapy can increase left posterior bundle branch engagement, for driving a graphical user interface configured to noninvasively assist the user in configuring one or more pacing parameters or settings, such as pacing rate, ventricular pacing rate, AV interval, VV interval, pacing pulse width, pacing vector, multi-point pacing vector (e.g., left ventricular vector quadrupole lead), pacing voltage, pacing configuration (e.g., biventricular pacing, right ventricular pacing only, left ventricular pacing only, etc.), as well as arrhythmia detection and treatment, rate adaptive settings, and performance, etc.

[0038] Computing device 140 can be operatively coupled to input device 142 and display device 130 to transmit data to and from each of the input devices 142 and 130, for example, and remote computing device 160 can be operatively coupled to input device 162 and display device 170 to transmit data to and from each of the input devices 162 and 170, for example,. For example, computing device 140 and remote computing device 160 can be electrically coupled to input devices 142, 162 and display devices 130, 170 using, for example, analog electrical connections, digital electrical connections, wireless connections, bus-based connections, network-based connections, Internet-based connections, etc. As further described herein, a user can provide input to input devices 142, 162 to view and / or select one or more cardiac therapy configuration information, left posterior bundle branch (LPB) ligation information (e.g., the degree of LPB ligation, an indication of whether LPB ligation has been adequately, partially, or inadequately ligated by cardiac therapy, etc.), and electrical heterogeneity information.

[0039] Although, as depicted, input device 142 is a keyboard and input device 162 is a touchscreen, it should be understood that input devices 142 and 162 may include any device capable of providing input to computing device 140 and computing device 160 to perform the functions, methods, and / or logic described herein. For example, input devices 142 and 162 may include a keyboard, mouse, trackball, touchscreen (e.g., capacitive touchscreen, resistive touchscreen, multi-touch touchscreen, etc.), etc. Similarly, display devices 130 and 170 may include any device capable of displaying information to the user, such as graphical user interfaces 132 and 172, including electrode status information, graphical representations of electrical activation, multiple signals from external electrodes on one or more heartbeats, QRS complex waves, selection areas for various cardiac therapy options, rankings of various cardiac therapy options, various pacing parameters, electrical heterogeneity information (EHI), text commands, graphical depictions of the anatomical structure of the human heart, images or graphical depictions of the patient's heart, graphical depictions of the locations of one or more electrodes, graphical depictions of the human torso, images or graphical depictions of the patient's torso, graphical depictions or actual images of implanted electrodes and / or leads, etc. Furthermore, display devices 130 and 170 may include liquid crystal displays, organic light-emitting diode screens, touch screens, cathode ray tube displays, etc.

[0040] It should be understood that computing device 140 and remote computing device 160 can be operatively coupled to each other in a variety of different ways to perform or execute the functions described herein. For example, in the depicted embodiment, computing device 140 can be operatively wirelessly coupled to remote computing device 160, as depicted by the wireless signal lines emitted therebetween. Alternatively, in contrast to a wireless connection, one or more of computing device 140 and remote computing device 160 can be operatively coupled via one or a wired electrical connection.

[0041] The processing programs or routines stored and / or executed by the computing device 140 and the remote computing device 160 may include programs or routines for computational mathematics, matrix mathematics, decomposition algorithms, compression algorithms (e.g., data compression algorithms), calibration algorithms, image construction algorithms, signal processing algorithms (e.g., various filtering algorithms, Fourier transform, fast Fourier transform, etc.), normalization algorithms, comparison algorithms, vector mathematics, or any other processing that implements one or more of the illustrative methods and / or processes described herein. The data stored and / or used by the computing device 140 and the remote computing device 160 may include, for example, electrical signal / waveform data (e.g., multiple QRS complex waves) from the electrode device 110, electrical activation time from the electrode device 110, heart sound / signal / waveform data from the acoustic sensor, graphics (e.g., graphic elements, icons, buttons, windows, dialog boxes, drop-down menus, graphics areas, graphics regions, 3D graphics, etc.), graphical user interfaces, results of one or more processing procedures or routines adopted according to this disclosure (e.g., electrical signals, electrical heterogeneity information, etc.), or any other data that can be used to perform or conduct one or more processes or methods described herein.

[0042] In one or more embodiments, the illustrative systems, methods, and interfaces may be implemented using one or more computer programs that execute on a programmable computer (e.g., a computer including, for example, processing power, data storage devices (e.g., volatile or non-volatile memory and / or storage elements), input devices, and output devices). The program code and / or logic described herein may be applied to input data to perform the functionality described herein and generate desired output information. The output information may be applied as input to one or more other means and / or methods described herein or to be applied in a known manner.

[0043] Any programmable language can be used to provide one or more programs for implementing the systems, methods, and / or interfaces described herein, such as high-level programs and / or object-oriented programming languages ​​suitable for communicating with computer systems. For example, any such program can be stored on any suitable means, such as a storage medium, readable by a general or special-purpose program that runs on a computer system (e.g., containing a processing device) to configure and operate the computer system to perform the programs described herein when read by a suitable device. In other words, at least in one embodiment, the illustrative systems, methods, and interfaces can be implemented using a computer-readable storage medium configured with computer programs, wherein such a storage medium causes a computer to operate in a specific and predefined manner to perform the functions described herein. Further, in at least one embodiment, the illustrative systems, methods, and interfaces can be described as being implemented by logic (e.g., object code) encoded in one or more non-transitory media, the logic containing code for execution and operable, when executed by a processor or processing circuitry system, to perform operations such as the methods, processes, and / or functions described herein.

[0044] Computing device 140 and remote computing device 160 can be, for example, any fixed or mobile computer system (e.g., controller, microcontroller, personal computer, microcomputer, tablet computer, etc.). The exact configuration of computing device 140 and remote computing device 160 is not limiting, and any device capable of providing suitable computing and control capabilities (e.g., signal analysis, mathematical functions such as median, mode, average, maximum value determination, minimum value determination, slope determination, minimum slope determination, maximum slope determination, graphics processing, etc.) can be used. As described herein, digital files can be any medium (e.g., volatile or non-volatile memory, CD-ROM, punched card, magnetically recordable magnetic tape, etc.) containing digital bits (e.g., encoded in binary or ternary) that can be read and / or written by computing device 140 and remote computing device 160 as described herein. Moreover, as described herein, a user-readable format file can be any representation of data (e.g., ASCII text, binary numbers, hexadecimal numbers, decimal numbers, graphics, etc.) that can be presented on any medium (e.g., paper, monitor, etc.) that can be read and / or understood by a user.

[0045] In view of the foregoing, it will be apparent that the functions described in one or more embodiments of this disclosure can be implemented in any manner known to those skilled in the art. Thus, the computer language, computer system, or any other software / hardware to be used to implement the processes described herein should not limit the scope of the systems, processes, or programs described herein (e.g., the functionality provided by such systems, processes, or programs).

[0046] The illustrative electrode device 110 can be configured to measure the body surface potential of the patient 114, and more specifically, to measure the trunk surface potential of the patient 114. For example... Figure 2 As shown, the illustrative electrode device 110 may include a group or array of external electrodes 112, a strip 113, and an interface / amplifier circuitry system 116. Electrodes 112 may be attached to or coupled to the strip 113, and the strip 113 may be configured to wrap around the torso of the patient 114 such that the electrodes 112 surround the patient's heart. As further shown, the electrodes 112 may be positioned around the patient 114, including posterior, lateral, posterolateral, anterior, and anterior locations of the patient 114's torso.

[0047] The illustrative electrode device 110 may also be configured to measure or monitor sounds from the patient 114 (e.g., heart sounds from the patient's torso). Figure 2 As shown, the illustrative electrode device 110 may include a group or array of acoustic sensors 120 attached to or coupled to the strip 113. The strip 113 may be configured to wrap around the torso of the patient 114 such that the acoustic sensors 120 surround the patient's heart. As further shown, the acoustic sensors 120 may be positioned around the patient 114, including posterior, lateral, rear, anterior, and frontal locations of the patient 114's torso.

[0048] Furthermore, electrode 112 and acoustic sensor 120 can be electrically connected to interface / amplifier circuitry 116 via wired connection 118. Interface / amplifier circuitry 116 can be configured to amplify signals from electrode 112 and acoustic sensor 120 and provide the signals to one or both of computing device 140 and remote computing device 160. Other illustrative systems may use wireless connections (e.g., as data channels) to transmit signals sensed by electrode 112 and acoustic sensor 120 to interface / amplifier circuitry 116, and further to one or both of computing device 140 and remote computing device 160. In one or more embodiments, interface / amplifier circuitry 116 may be electrically coupled to one or both of computing device 140 and remote computing device 160 using, for example, analog electrical connections, digital electrical connections, wireless connections, bus-based connections, network-based connections, Internet-based connections, etc.

[0049] Despite Figure 2In one example, electrode device 110 includes a strip 113, but in other examples, any of a variety of mechanisms, such as tape or adhesive, can be used to assist in the spacing and placement of electrodes 112 and acoustic sensors 120. In some examples, strip 113 may comprise elastic bands, tape strips, or cloth. Further, in some examples, strip 113 may be part of or integrated with a garment (e.g., a T-shirt). In other examples, electrodes 112 and acoustic sensors 120 may be placed separately on the torso of patient 114. Further, in other examples, one or both of electrodes 112 (e.g., arranged in an array) and acoustic sensors 120 (e.g., also arranged in an array) may be patches, vests, and / or other means of securing electrodes 112 and acoustic sensors 120 to or within the torso of patient 114. Furthermore, in other embodiments, one or both of the electrodes 112 and the acoustic sensors 120 may be two portions of material or part of two patches or positioned therein. One of the two patches may be positioned on the front side of the patient 114's torso (e.g., to monitor electrical signals representing the front side of the patient's heart, measure the electrical activation time of an alternative heart representing the front side of the patient's heart, monitor or measure sound on the front side of the patient, etc.) and the other patch may be positioned on the rear side of the patient 114's torso (e.g., to monitor electrical signals representing the rear side of the patient's heart, measure the electrical activation time of an alternative heart representing the rear side of the patient's heart, monitor or measure sound on the rear side of the patient, etc.). Also, in other embodiments, one or both of the electrodes 112 and the acoustic sensors 120 may be arranged to extend from the front side of the patient 114 across the left side of the patient 114 to the top and bottom rows on the rear side of the patient 114. Furthermore, in other instances, one or both of the electrodes 112 and the acoustic sensors 120 may be arranged in a curve around the axillary region, and the electrode / sensor density on the right chest may be lower than the density in the other remaining regions.

[0050] Electrodes 112 can be configured to surround the heart of patient 114 and record or monitor electrical signals associated with cardiac depolarization and repolarization after a signal has propagated through the torso of patient 114. Each electrode in 112 can be used in a monopolar configuration to sense torso surface potentials reflecting cardiac signals. Interface / amplifier circuitry 116 can also be coupled to a return electrode or an unrelated electrode (not shown) that can be used in combination with each electrode 112 for monopolar sensing.

[0051] In some instances, there may be approximately 12 to approximately 50 electrodes 112 spatially distributed around the patient's torso, and approximately 12 to approximately 50 acoustic sensors 120. Other configurations may have more or fewer electrodes 112 and more or fewer acoustic sensors 120. It should be understood that the electrodes 112 and acoustic sensors 120 may not be arranged or distributed in an array extending all around or completely around the patient 114. Alternatively, the electrodes 112 and acoustic sensors 120 may be arranged in an array that extends around only a portion or part of the patient 114. For example, the electrodes 112 and acoustic sensors 120 may be distributed on the front, back, and left sides of the patient, with fewer or no electrodes and acoustic sensors on the right side (including the posterior and anterior regions of the patient's right side).

[0052] One or both of the computing device 140 and the remote computing device 160 can record and analyze trunk surface potential signals sensed by electrode 112 and sound signals sensed by acoustic sensor 120, which are amplified / modulated by interface / amplifier circuitry system 116. Additionally, one or both of the computing device 140 and the remote computing device 160 can be configured to analyze electrical signals from electrode 112 to provide electrocardiogram (ECG) signals, information such as EHI, or data from the patient's heart, as will be further described herein. Furthermore, one or both of the computing device 140 and the remote computing device 160 can be configured to analyze electrical signals from acoustic sensor 120 to provide sound signals, information, or data from the patient's body and / or implanted devices (such as left ventricular assist devices).

[0053] Additionally, computing device 140 and telecomputing device 160 may be configured to provide graphical user interfaces 132, 172 that depict various information associated with electrode device 110 and data collected or sensed using electrode device 110. For example, graphical user interfaces 132, 172 may depict electroactivation maps and EHIs obtained using electrode device 110. For example, graphical user interfaces 132, 172 may depict ECGs containing QRS complexes obtained using electrode device 110 and acoustic data containing sound waves obtained using acoustic sensor 120, along with other related information. The illustrative system and method can noninvasively use the electrical information collected using electrode device 110 and the acoustic information collected using acoustic sensor 120 to assess a patient's cardiac health and evaluate and configure cardiac therapies delivered to the patient. More specifically, the illustrative system and method can noninvasively use the electrical information collected using electrode device 110 to determine whether a patient's left posterior bundle branch has been engaged by cardiac therapy, and, for example, the degree to which the patient's left posterior bundle branch has been engaged.

[0054] Furthermore, the electrode device 110 may further include reference electrodes and / or drive electrodes, for example, to be positioned around the lower torso of the patient 114, which may be further used by the system 100. For example, the electrode device 110 may include three reference electrodes, and signals from the three reference electrodes may be combined to provide a reference signal. Alternatively, the electrode device 110 may use three tail-end reference electrodes (e.g., instead of the standard reference electrodes used in the Wilson Central Terminal) to obtain a “true” unipolar signal with less noise by averaging the reference signals from the three tail-end positions.

[0055] Figure 3 Another illustrative electrode device 110 is shown, comprising a plurality of electrodes 112 and a plurality of acoustic sensors 120. The electrodes are configured to surround the heart of a patient 114 and record or monitor electrical signals associated with cardiac depolarization and repolarization after the signal has propagated through the torso of the patient 114. The acoustic sensors are configured to surround the heart of the patient 114 and record or monitor cardiac-related sound signals after the signal has propagated through the torso of the patient 114. The electrode device 110 may include a vest 114 to which the plurality of electrodes 112 and the plurality of acoustic sensors 120 may be attached or coupled. In at least one embodiment, the plurality of electrodes 112 or an array of the electrodes may be used to collect electrical information, such as alternative electrical activation time. Figure 2 The electrode device 110 is similar. Figure 3 The electrode device 110 may include an interface / amplifier circuitry 116 electrically coupled to each of the electrodes 112 and acoustic sensors 120 via a wired connection 118 and configured to transmit signals from the electrodes 112 and acoustic sensors 120 to a computing device 140. As shown, the electrodes 112 and acoustic sensors 120 may be distributed on the torso of the patient 114, including, for example, the posterior surface, lateral surface, posterolateral surface, anterior surface, and anterior position of the torso of the patient 114.

[0056] Vest 114 may be formed of fabric, with electrodes 112 and acoustic sensors 120 attached to the fabric. Vest 114 may be configured to maintain the positioning and spacing of electrodes 112 and acoustic sensors 120 on the torso of patient 114. Further, vest 114 may be marked to aid in determining the position of electrodes 112 and acoustic sensors 120 on the surface of the torso of patient 114. In some instances, although approximately 25 to approximately 256 electrodes 112 and approximately 25 to approximately 256 acoustic sensors 120 may be distributed around the torso of patient 114, other configurations may have more or fewer electrodes 112 and more or fewer acoustic sensors 120.

[0057] The illustrative systems and methods described herein can be used to provide noninvasive assistance to users in the assessment and evaluation of left posterior bundle branch engagement via cardiac therapies such as VfA pacing, left ventricular septal basement pacing, etc. Additionally, the illustrative systems and methods described herein can be used in the configuration of cardiac therapies currently delivered to patients (e.g., via implantable medical devices such as VfA pacing devices). For example, the illustrative systems and methods can be used to assist users in improving left posterior bundle branch activation by providing guidance on adjusting and / or automatically adjusting cardiac therapies.

[0058] Figure 4 The illustration 200 describes the assessment of left posterior bundle branch engagement and the adjustment of cardiac therapy. Generally, it can be described that the illustration 200 can be used to analyze external electrical activity (e.g., from the patient's posterior trunk region) during the delivery of cardiac pacing therapy and to use such electrical activity to determine whether cardiac therapy has resulted in left posterior bundle branch engagement and the extent of any additional engagement.

[0059] As shown, method 200 may include monitoring electrical activity 202. In one embodiment, electrical activity may be measured from outside the patient. In other words, electrical activity may be measured from tissues outside the patient's body (e.g., skin). For example, method 200 may include using multiple external electrodes to monitor or measure electrical activity, such as regarding... Figure 1-3 As shown and described. In one embodiment, the plurality of external electrodes may be part of or incorporated into a vest or strap positioned around the patient's torso. More specifically, the plurality of electrodes may be described as external surface electrodes positioned in an array and configured to be located near the skin of the patient's torso. It can be described that, when using the plurality of external electrodes, the monitoring process 202 can provide multiple electrocardiograms (ECGs), signals representing the depolarization and repolarization of the patient's heart, and / or multiple activation times. More specifically, the multiple ECGs can be used to generate alternative activation times representing cardiac depolarization.

[0060] Electrical activity can be monitored from a posterior subset of electrodes positioned around or near the posterior part of the patient's trunk 202. The electrical activity or signal captured from the posterior subset of electrodes may represent one or more posterior regions of the patient's heart, such as the posterior branch or the left posterior bundle branch. In one instance, the posterior subset of electrodes may be positioned on the posterior and posterolateral regions of the patient's trunk.

[0061] Method 200 may include delivering cardiac therapy 204, such as cardiac pacing therapy, using an implantable or non-implantable device designed to pace or deliver electrical pacing to one or more zones or regions of a patient's heart. Cardiac pacing therapy may include, but is not limited to, atrial-to-ventricular (VfA) pacing therapy, left ventricular basal septal pacing therapy, His bundle pacing therapy, and interventricular septal left ventricular endocardial pacing therapy.

[0062] VfA pacing therapy is referenced in this article. Figure 7-10 Additionally, it is described and illustrated. VfA pacing therapy can be configured to deliver electrical pacing to one or more areas of the cardiac conduction system, including, but not limited to, areas of the left and right bundle branches, one or more areas of the left ventricle, one or more areas of the right atrium, etc.

[0063] Another example of cardiac conduction system pacing therapy is His bundle pacing therapy, as described in, for example, U.S. Patent Application Serial No. 16 / 163,132, filed October 17, 2018, entitled "His Bundle and Bundle Branch Pacing Adjustment". Yet another example of cardiac conduction system pacing therapy is septal left ventricular endocardial pacing therapy, as described in, for example, U.S. Patent No. 7,177,704, published February 13, 2007, entitled "Pacing Method and Apparatus".

[0064] During the delivery of cardiac pacing therapy 204, electrical activity can be continuously monitored 202 and used to generate electrical heterogeneity information (EHI) 206. EHI (e.g., data) can be defined as information indicating at least one of mechanical or asynchronicity of the heart and / or electrical or asynchronicity of the heart. In other words, EHI can represent an alternative to the actual mechanical and / or electrical function of the patient's heart. In at least one embodiment, relative changes in EHI (e.g., from baseline heterogeneity information to therapeutic heterogeneity information, from a first set of heterogeneity information to a second set of therapeutic heterogeneity information, etc.) can be used to determine alternative values ​​representing changes in hemodynamic response (e.g., a sharp change in the LV pressure gradient). Left ventricular pressure is typically monitored invasively using a pressure sensor located in the left ventricle of the patient's heart. Thus, using EHI to determine alternative values ​​representing left ventricular pressure avoids the need for invasive monitoring using a left ventricular pressure sensor.

[0065] In at least one embodiment, EHI may include the use of, for example, methods described herein. Figure 1-3 The standard deviation of the ventricular activation time measured by some or all of the external electrodes of the described electrode device 110. Additionally, the local or regional EHI may include the standard deviation and / or mean of the activation time measured using electrodes located in certain anatomical regions of the trunk. For example, an external electrode on the posterior aspect of the patient's trunk can be used to calculate the local or regional posterior EHI. Alternatively, for example, an external electrode on the left side of the patient's trunk can be used to calculate the local or regional left-sided EHI.

[0066] EHI can be generated using one or more different systems and / or methods. For example, EHI can be generated using arrays or multiple surface electrodes and / or imaging systems as described below: U.S. Patent Application Publication No. 2012 / 0283587A1, published November 8, 2012, entitled "Assessing Intra-Cardiac Activation Patterns and Electrical Dyssynergy"; U.S. Patent Application Publication No. 2012 / 0284003A1, published November 8, 2012, entitled "Assessing Intra-Cardiac Activation Patterns"; and U.S. Patent No. 8,180,428B2, published May 15, 2012, entitled "Methods and Systems for Using Inselecting Cardiac Pacing Sites".

[0067] EHI may include one or more measures or indices that focus on or refer to alternative activation times measured from the posterior and posterolateral regions of the patient's trunk. For example, one measure or indice of electrical heterogeneity may be the mean or average (MPAT) of alternative posterior electrical activation times monitored by posterior electrodes positioned around the posterior and / or posterolateral regions of the patient's trunk. In some instances, MPAT may be estimated using estimated cardiac activation times on the surface of a model heart. Another measure or indice of electrical heterogeneity or synchronicity may be the percentage of alternative early activation electrical activation times (PEPA) monitored by posterior electrodes positioned around the posterior and / or posterolateral regions of the patient's trunk.

[0068] MPAT and PEPA can be determined (e.g., estimated, calculated, generated, produced, etc.) based solely on electrical activity measured by electrodes located near the patient's posterior side, which may be referred to as "posterior" electrodes. A posterior electrode can be defined as any surface electrode located near the posterior side of the patient's heart in the body or trunk region encompassing the patient's spine. In one embodiment, a posterior electrode may include all electrodes on the patient's posterior side. In another embodiment, a posterior electrode may include all electrodes located on the patient's posterior side and positioned between the patient's spine and the patient's left side. In yet another embodiment, a posterior electrode may be designated based on the contour of the posterior part of the heart determined using imaging equipment (e.g., X-ray, fluoroscopy, etc.), which may be projected onto various corresponding surface electrodes positioned around the patient's trunk.

[0069] The illustrative method 200 may additionally include determining left posterior bundle branch fusion 208 based on one or both of the generated EHIs, such as MPAT and PEPA. For example, the generated EHIs may be analyzed to determine the degree of left posterior bundle branch fusion.

[0070] In one embodiment, the degree of left posterior bundle branch (LPB) engagement can range from complete LPB engagement to inadequate LPB engagement. Complete LPB engagement can be defined as engagement of all or substantially all of the left posterior bundle branch by cardiac therapy. Adequate LPB engagement can be defined as engagement of a portion of the left posterior bundle branch by cardiac therapy to provide effective and adequate left ventricular function. Partial LPB engagement can be defined as engagement of only a portion of the left posterior bundle branch by cardiac therapy to provide partially effective and partially adequate left ventricular function. Inadequate LPB engagement can be defined as engagement of only a small portion of the left posterior bundle branch by cardiac therapy to provide inefficient and inadequate left ventricular function. Therefore, method 200 can determine whether cardiac therapy has resulted in complete LPB engagement, adequate LPB engagement, partial LPB engagement, or inadequate LPB engagement.

[0071] In one or more embodiments, the average value of the alternative posterior electrical activation time (MPAT) monitored by the posterior electrode can be used to assess left posterior bundle branch engagement. MPAT can be compared to one or more thresholds or ranges to determine the degree of left posterior bundle branch engagement. For example, if MPAT is less than or equal to 30 ms, then left bundle branch engagement can be determined to be sufficient. Alternatively, if MPAT is greater than 30 ms and less than 50 ms, then left bundle branch engagement can be determined to be partial. Yet another example, if MPAT is greater than or equal to 50 ms, then left bundle branch engagement can be determined to be insufficient. It should be understood that such thresholds and ranges in this embodiment are merely one example, and other similar thresholds and ranges are also considered in this disclosure.

[0072] In one or more embodiments, the percentage of alternative early activation electrical activation time (PEPA) monitored by the posterior electrode can be used to assess left posterior bundle branch junction. To determine whether activation by the posterior electrode or monitored by the posterior electrode constitutes early activation, the activation time can be compared to an early activation threshold. Electrodes with measured activation times less than or equal to the early activation threshold can be indicated as electrodes with early activation, while electrodes with measured activation times greater than the early activation threshold can be indicated as electrodes without early activation. The early activation threshold can be between about 15 milliseconds and about 50 milliseconds. In one embodiment, the early activation threshold is 35 milliseconds. In other embodiments, the early activation threshold can be greater than or equal to about 15 milliseconds, greater than or equal to about 25 milliseconds, and greater than or equal to about 30 milliseconds and / or less than or equal to about 50 milliseconds and less than or equal to about 40 milliseconds.

[0073] Therefore, the early activation electrode, as determined by the early activation threshold, can be divided by the total number of posterior electrodes to provide a PEPA (partially activated electrical area), and the PEPA can then be used to determine the degree of left posterior bundle branch conjunctival engagement. For example, if the PEPA is greater than 75%, then the left bundle branch is considered adequately conjunctival. Alternatively, for example, if the PEPA is greater than or equal to 50% and less than or equal to 75%, then the left bundle branch is considered partially conjunctival. Still another example, for example, if the PEPA is less than 50%, then the left bundle branch is considered inadequately conjunctival.

[0074] The anterior and posterior electrical activation maps depicting the full left posterior bundle branch junction are shown in the diagram. Figure 5A In the middle, the anterior and posterior electrical activation maps depicting the left posterior bundle branch junction are shown. Figure 5B In the middle, and depicting the anterior and posterior electrical activation maps of the insufficient left posterior bundle branch junction, depicting... Figure 5C In the middle. Each graph contains a front activation graph on the left, a back activation graph on the right, and a back EHI, or MPAT, drawn below each back graph.

[0075] like Figure 5A As shown, the rear view illustrates homogeneous early activation and associated MPAT, i.e., 21 ms < 30 ms, indicating adequate left posterior bundle branch engagement. Figure 5B As shown, the rear view illustrates partial early activation and associated MPAT, i.e., 44 ms less than 50 ms but greater than 30 ms, which indicates partial left posterior bundle branch engagement. Figure 5C As shown, the rear view illustrates a small amount of early activation and associated MPAT, i.e., 80 ms > 50 ms, which indicates insufficient left posterior bundle branch engagement.

[0076] The same front and rear electroactivation maps are depicted in Figures 6A-6CHowever, these maps also include electrode representations 220 overlaid on the posterior electrical activation map, indicating the relative positions of the corresponding electrodes with respect to the patient's posterior trunk region. Electrodes with measured early activation less than the illustrative early activation threshold of 35 ms are represented by circles with crosshairs (e.g., crosshair filled), and electrodes with measured early activation greater than or equal to the illustrative early activation threshold of 35 ms are represented by circles without crosshairs (e.g., no filling).

[0077] Additionally, each figure includes a rear EHI, or PEPA, depicted below each rear figure, which, as described herein, represents the percentage of electrodes with early activation. Since the electrodes are graphically depicted by electrode representation 220, PEPA can be described as the cross-hatched electrode representation 220 divided by the total number of rear electrodes. Figure 6A As shown, the rear view illustrates homogeneous early activation and associated PEPA, with 78% (39 out of 50 electrodes) greater than 75%, indicating adequate left posterior bundle branch engagement. Figure 5B As shown, the rear diagram illustrates partial early activation and associated PEPA, where 54% (27 out of 50 electrodes) is less than 75% but greater than 50%, indicating partial left posterior bundle branch engagement. Figure 5C As shown, the rear view shows a small amount of early activation and associated PEPA, namely 14% (7 out of 50 electrodes) less than 50%, which indicates insufficient left posterior bundle branch engagement.

[0078] One or more posterior EHI measurements may be combined or used together to determine left posterior bundle branch engagement. In one embodiment, MPAT may be used in conjunction with PEPA to determine left posterior bundle branch engagement. For example, if PEPA is greater than 75% and MPAT is less than or equal to 30 ms, then left bundle branch engagement is determined to be adequate. Alternatively, for example, if PEPA is greater than or equal to 50% and less than or equal to 75% and MPAT is greater than 30 ms and less than 50 ms, then left bundle branch engagement is determined to be partial. Yet another way, for example, if PEPA is less than 50% and MPAT is greater than or equal to 50 ms, then left bundle branch engagement is determined to be inadequate.

[0079] After the illustrative method 200 has determined the left posterior bundle branch engagement 208, method 200 may additionally include adjustments or modifications to the cardiac therapy 210 to, for example, increase the left posterior bundle branch engagement in an effort to provide more effective cardiac function. It should be understood that when adjusting the cardiac therapy, the left posterior bundle branch engagement may be only one factor to consider, and therefore, the cardiac therapy adjustments described regarding the engagement of the left posterior bundle branch may be used in conjunction with other factors not described herein.

[0080] Method 200 can adjust cardiac pacing therapy 208 in various ways. For example, cardiac pacing therapy may include or define multiple different pacing settings or parameters that can be adjusted. Multiple pacing settings may include, but are not limited to, pacing electrode position, pacing electrode angle, pacing amplitude or power, pacing time such as AV delay, VV delay and pacing pulse length, use of one or more pacing electrodes, and / or use of one or more pacing vectors. In other words, one or more of the pacing settings can be changed (e.g., increased, decreased, moved, etc.) during adjustment of cardiac pacing therapy 208.

[0081] After adjusting cardiac pacing therapy 208, method 200 may return to generating EHI 206 from electrical activity monitored during the newly adjusted cardiac pacing therapy. Method 200 may then readjust cardiac pacing therapy 210, generating EHI 206, determining left posterior bundle branch engagement 208, and continue cycling until multiple different cardiac pacing therapy configurations are tried, each with at least one different pacing parameter. In one embodiment, the pacing settings may be adjusted incrementally in steps or percentages, “sweeping” through a range of possible parameters for each particular setting. For example, AV delay may start at a level equal to 70% of the patient’s inherent AV delay and may be gradually reduced in steps of approximately 10 milliseconds to approximately 20 milliseconds, up to a predefined minimum of 60 milliseconds. Additionally, for example, the pacing settings may be the position or angle of the pacing electrode, and the position or angle of the pacing electrode may be incrementally adjusted by the implanter to provide a range of different positions and angles.

[0082] It can be described that processes 206, 208, and 210 define a “closed loop.” For example, processes 206, 208, and 210 may loop for multiple different pacing settings or configurations, and for each of the multiple different pacing settings or configurations, generating EHI information 206 and determining left posterior bundle branch engagement 208. The EHI generated for multiple different pacing settings or configurations, and consequently the determination of left posterior bundle branch engagement, can then be used to determine the pacing setting for the selected cardiac pacing therapy 212. In some embodiments, the pacing setting for the selection of cardiac conduction therapy may be referred to as the “optimal” pacing setting, for example, the pacing setting that provides the most complete left posterior bundle branch engagement may be selected. However, it should be understood that the pacing setting that provides the most complete left posterior bundle branch engagement may not necessarily be the pacing setting selected as a consideration other than the presence of left posterior bundle branch engagement, such as the battery life of the device performing the therapy. Therefore, the selected or optimal pacing setting for cardiac pacing therapy may represent a balance of many factors including left posterior bundle branch engagement.

[0083] For example, MPAT can be used to determine the pacing setting 212 for the selection of cardiac pacing therapy. Thus, multiple different pacing settings 210 can be utilized, and MPAT 2018 can be generated for each of the multiple different pacing settings. In this example, the lowest MPAT can indicate the most complete left posterior bundle branch engagement of the cardiac pacing therapy, and therefore, the cardiac pacing therapy setting having or corresponding to the lowest MPAT can be selected 212 for use with the cardiac pacing therapy.

[0084] Further illustrative systems, methods, and processes for optimizing cardiac pacing therapy are described in U.S. Patent Application Serial No. 15 / 934,517, entitled "Evaluation of Ventricle from Atrium Pacing Therapy," filed March 23, 2019, and U.S. Provisional Patent Application Serial No. 62 / 725,763, entitled "Adaptive VFA Cardiac Therapy," filed August 31, 2018.

[0085] Figure 7 Describes an illustrative atrium-to-ventricle (VfA) cardiac therapy system, said system being configurable with, for example, those described herein. Figure 1 The system and method described in -6 are used together. Although it should be understood that this disclosure can utilize one or both of leadless and ledged implantable medical devices, Figure 7The illustrative cardiac therapy system includes a leadless intracardiac medical device 10, which can be configured for single-chamber or dual-chamber therapy and implanted in a patient's heart 8. In some embodiments, the device 10 can be configured for single-chamber pacing and can be switched, for example, between single-chamber pacing and multi-chamber pacing (e.g., dual-chamber or triple-chamber pacing). As used herein, "intracardiac" means a device configured to be completely implanted within a patient's heart, for example, to provide cardiac therapy. A device 10 is shown implanted in a target implantation region 4 in the right atrium (RA) of a patient's heart 8. The device 10 may include one or more fixation members 20 anchoring the distal end of the device 10 to the atrial endocardium in the target implantation region 4. The target implantation region 4 may be located between the His bundle 5 and the coronary sinus 3 and may be adjacent to or immediately adjacent to the tricuspid valve 6. Device 10 can be described as an atrial-ventricular device because it can perform one of two things simultaneously, while typically placed in the right atrium: sensing electrical activity from one or both ventricles (e.g., the right ventricle, the left ventricle, or both ventricles, as appropriate) and providing therapy thereto. Specifically, device 10 may include a tissue-piercing electrode that can be implanted from the Koch's triangle region of the right atrium through the right atrial endocardium and central fibrous body into the base and / or septal region of the left ventricular myocardium of the patient's heart.

[0086] Device 10 can be described as a leadless implantable medical device. As used herein, "leadless" means a device without leads extending from the patient's heart 8. Further, although a leadless device may have leads, the leads do not extend from outside the patient's heart to inside the heart or from inside the heart to outside the heart. Some leadless devices can be introduced through a vein, but once implanted, the device has no or may not contain any transvenous leads and can be configured to provide cardiac therapy without the use of any transvenous leads. Further, when the device housing is positioned in the atrium, specifically, the leadless VfA device does not use leads to operatively connect to electrodes in the ventricle. Additionally, leadless electrodes can be coupled to the housing of the medical device without the use of leads between the electrodes and the housing.

[0087] Device 10 may include a dart electrode assembly 12 defining or having a straight axis extending from a distal region of device 10. The dart electrode assembly 12 may be placed or at least configured to pass through the atrial myocardium and central fibrous body and enter into the ventricular myocardium 14 or along the interventricular septum without completely penetrating the endocardial or epicardial surface of the ventricle. The dart electrode assembly 12 may carry or include an electrode at the distal region of the axis, such that the electrode can be positioned within the ventricular myocardium for sensing ventricular signals and delivering ventricular pacing pulses (e.g., depolarizing the left and / or right ventricles to induce contraction of the left and / or right ventricles). In some instances, the electrode at the distal region of the axis is a cathode electrode provided for use in a bipolar electrode pair for pacing and sensing. While the implantation region 4 shown allows one or more electrodes of the dart electrode assembly 12 to be positioned in the ventricular myocardium, it should be recognized that devices having the aspects disclosed herein can be implanted in other locations where appropriate for multi-chamber pacing (e.g., dual-chamber or triple-chamber pacing), single-chamber pacing with multi-chamber sensing, single-chamber pacing and / or sensing, or other clinical therapies and applications.

[0088] It should be understood that although the device 10 is described herein as comprising a single dart electrode assembly, the device 10 may comprise more than one dart electrode assembly, which is placed or configured to be placed through the atrial myocardium and central fibrous body and into the ventricular myocardium 14 or along the interventricular septum, without completely passing through the ventricular endocardium or epicardial surface. Additionally, each dart electrode assembly may carry or comprise more than one electrode in a distal region of the axis or in other regions along the axis (e.g., a proximal region or a central region).

[0089] The cardiac therapy system 2 may also include a separate medical device 50 (in Figure 7(Illustrated schematically) The individual medical device 50 may be positioned outside (e.g., subcutaneously) the patient's heart 8 and may be operatively coupled to the patient's heart 8 to deliver cardiac therapy thereto. In one example, the individual medical device 50 may be an extravascular ICD. In some embodiments, the extravascular ICD may include a defibrillation lead containing or carrying a defibrillation electrode. A therapy carrier may be present between the defibrillation electrode on the defibrillation lead and the housing electrode of the ICD. Further, one or more electrodes of the ICD may also be used to sense electrical signals in relation to the patient's heart 8. The ICD may be configured to deliver electrical shock therapy comprising one or more defibrillation or cardioversion shocks. For example, if an arrhythmia is sensed, the ICD may transmit pulses via the lead to shock the heart and restore its normal rhythm. In some instances, the ICD may deliver electrical shock therapy without placing the lead inside the heart or attaching the wire directly to the heart (subcutaneous ICD). Examples of vascular perivascular subcutaneous ICDs that can be used with System 2 described herein can be described in U.S. Patent No. 9,278,229 (Reinke et al.), published March 8, 2016.

[0090] In the case of electrical shock therapy (e.g., defibrillation shock delivered by defibrillation electrodes via defibrillation leads), a standalone medical device 50 (e.g., an extravascular ICD) may include control circuitry that uses a therapy delivery circuit to generate a defibrillation shock with any of a variety of waveform characteristics, including leading-edge voltage, slope, delivered energy, pulse phase, etc. The therapy delivery circuitry may, for example, generate monophasic, biphasic, or multiphasic waveforms. Additionally, the therapy delivery circuitry may generate defibrillation waveforms with varying amounts of energy. For example, the therapy delivery circuitry may generate a defibrillation waveform delivering a total of approximately 60-80 joules (J) of energy for subcutaneous defibrillation.

[0091] The individual medical device 50 may further include sensing circuitry. The sensing circuitry may be configured to acquire electrical signals sensed by one or more combinations of electrodes and to process the acquired signals. Components of the sensing circuitry may include analog components, digital components, or combinations thereof. The sensing circuitry may, for example, include one or more sense amplifiers, filters, rectifiers, threshold detectors, analog-to-digital converters (ADCs), etc. The sensing circuitry may convert the sensed signals into digital form and provide the digital signals to control circuitry for processing and / or analysis. For example, the sensing circuitry may amplify the signal from the sensing electrodes and convert the amplified signal into a multi-bit digital signal via an ADC, and then provide the digital signal to the control circuitry. In one or more embodiments, the sensing circuitry may also compare the processed signal with a threshold to detect the presence of atrial or ventricular depolarization (e.g., P wave or R wave) and indicate the presence of atrial depolarization (e.g., P wave) or ventricular depolarization (e.g., R wave) to the control circuitry.

[0092] Device 10 and a separate medical device 50 can cooperate to provide cardiac therapy to a patient's heart 8. For example, device 10 and the separate medical device 50 can be used to detect tachycardia, monitor tachycardia, and / or provide tachycardia-related therapy. For example, device 10 can wirelessly communicate with the separate medical device 50 to trigger an electric shock therapy using the separate medical device 50. As used herein, "wireless" means an operative coupling or connection between device 10 and the separate medical device 50 that does not use a metallic conductor. In one example, wireless communication can use a unique, signaling, or triggering electrical pulse provided by device 10 that is conducted through the patient's tissue and can be detected by the separate medical device 50. In another example, wireless communication can use the communication interface (e.g., an antenna) of device 10 to provide electromagnetic radiation that propagates through the patient's tissue and can be detected, for example, using the communication interface (e.g., an antenna) of the separate medical device 50.

[0093] Figure 8 for Figure 7 An enlarged conceptual diagram of the anatomy of an intracardiac medical device 10 and a patient's heart 8. Specifically, device 10 is configured to sense electrical activity and / or deliver pacing therapy. Intracardiac device 10 may include a housing 30. Housing 30 may define internal components of device 10 (such as those used in conjunction with...). Figure 10The generally described sensing circuitry, therapy delivery circuitry, control circuitry, memory, telemetry circuitry, other optional sensors, and power supply reside in a hermetically sealed internal cavity. The housing 30 may contain (e.g., formed therefrom or derived therefrom) conductive materials such as titanium or titanium alloys, stainless steel, MP35N (a non-magnetic nickel-cobalt-chromium-molybdenum alloy), platinum alloys, or other biocompatible metals or metal alloys. In other examples, the housing 30 may contain (e.g., formed therefrom or derived therefrom) non-conductive materials, including ceramics, glass, sapphire, silicone, polyurethane, epoxy resin, acetyl copolymer plastics, polyetheretherketone (PEEK), liquid crystal polymers, or other biocompatible polymers.

[0094] In at least one embodiment, the housing 30 may be described as extending between the distal region 32 and the proximal region 34 and as defining a generally cylindrical shape, for example, to facilitate catheter delivery. In other embodiments, the housing 30 may be prismatic or any other shape to perform the functions and utilities described herein. The housing 30 may include, for example, a delivery tool interface member 26 defined or positioned at the proximal region 34 for engagement with a delivery tool during implantation of the device 10.

[0095] All or a portion of the housing 30 can serve as a sensing and / or pacing electrode during cardiac therapy. In the illustrated example, the housing 30 includes a proximal housing-based electrode 24 external to a proximal portion of the housing 30 (e.g., closer to the proximal region 34 than the distal region 32). When the housing 30 (e.g., defined by a conductive material, formed of, etc., of which), portions of the housing 30 can be electrically insulated by a non-conductive material (e.g., a coating of parylene, polyurethane, silicone, epoxy, or other biocompatible polymers), thereby exposing one or more discrete regions of the conductive material to form or define the proximal housing-based electrode 24. When the housing 30 (e.g., defined by or formed of a non-conductive material, such as ceramic, glass, or polymeric materials), a conductive coating or layer, such as titanium, platinum, stainless steel, or alloys thereof, can be applied to one or more discrete regions of the housing 30 to form or define the proximal housing-based electrode 24. In other instances, the proximal housing-based electrode 24 may be a component mounted or assembled onto the housing 30, such as a ring electrode. The proximal housing-based electrode 24 may be electrically coupled to the internal circuitry of the device 10, for example, via a conductive housing 30 or, when the housing 30 is made of a non-conductive material, via an electrical conductor.

[0096] In the illustrated example, the proximal housing-based electrode 24 is positioned closer to the proximal housing region 34 than the distal housing region 32, and thus can be referred to as the proximal housing-based electrode 24. However, in other examples, the proximal housing-based electrode 24 may be positioned at other locations along the housing 30, for example, further away from the illustrated location.

[0097] At the distal region 32, the device 10 may include a distal fixation and electrode assembly 36, which may include one or more fixation members 20 and one or more dart electrode assemblies 12 of equal or unequal length. In one such example as shown, a single dart electrode assembly 12 includes a shaft 40 extending distally away from the distal region 32 of the housing, and one or more electrode elements, such as a tip electrode 42, at or near the free distal region of the shaft 40. The tip electrode 42 may have a conical or hemispherical distal tip with a relatively narrow tip diameter (e.g., less than about 1 mm) for penetration and through tissue layers without the need for sharp or beveled tips or needle-like tips.

[0098] The dart electrode assembly 12 can be configured to pierce one or more tissue layers to position the tip electrode 42 within a desired tissue layer (e.g., ventricular myocardium). Thus, the height 47 or length of the shaft 40 can correspond to the intended pacing site depth, and the shaft 40 can have relatively high compressive strength along its longitudinal axis to resist bending in the lateral or radial directions when pressed and inserted into the implantation region 4. If a second dart electrode assembly 12 is used, its length may not be equal to the intended pacing site depth and can be configured to act as an independent electrode for delivering pacing energy to and / or sensing signals from said tissue. In one embodiment, a longitudinal axial force can be applied to the tip electrode 42, for example, by applying a longitudinal thrust to the proximal region 34 of the housing 30, to advance the dart electrode assembly 12 into the tissue within the target implantation region.

[0099] Shaft 40 can be described as longitudinally non-compressible and / or elastically deformable in the transverse or radial direction when subjected to transverse or radial forces, allowing for temporary bending, for example, with tissue movement, but returning to its normal straight positioning when the transverse force decreases. Therefore, the dart electrode assembly 12 containing shaft 40 can be described as elastic. When shaft 40 is not exposed to any external force or is only exposed to a force along its longitudinal central axis, shaft 40 can maintain a straight, linear positioning as shown.

[0100] In other words, the shaft 40 of the dart electrode assembly 12 can normally be a straight member and can be rigid. In other embodiments, the shaft 40 can be described as relatively rigid, but still possessing limited flexibility in the lateral direction. Further, the shaft 40 can be non-rigid to allow some lateral bending with heart movement. However, in a relaxed state, when not subjected to any external force, the shaft 40 can maintain a straight positioning as shown to space the tip electrode 42 from the distal region 32 of the housing by at least the height or length 47 of the shaft 40.

[0101] The one or more fixation members 20 can be described as one or more “teeth” having a normal bending positioning. The teeth can be held in a distally extending position within the delivery tool. The distal tip of the teeth can penetrate cardiac tissue to a limited depth before elastically or resiliently bending back to the normal bending positioning (as shown) proximally upon release from the delivery tool. Further, the fixation member 20 can include one or more aspects described, for example, in U.S. Patent No. 9,675,579, issued June 13, 2017 (Grubac et al.) and U.S. Patent No. 9,119,959, issued September 1, 2015 (Rys et al.).

[0102] In some instances, the distal fixation and electrode assembly 36 includes a distal housing-based electrode 22. When using the device 10 as a pacemaker for multi-chamber pacing (e.g., dual-chamber or triple-chamber pacing) and sensing, the tip electrode 42 can serve as a cathode electrode paired with the proximal housing-based electrode 24, which acts as a return anode electrode. Alternatively, the distal housing-based electrode 22 can serve as a return anode electrode paired with the tip electrode 42 for sensing ventricular signals and delivering ventricular pacing pulses. In other instances, the distal housing-based electrode 22 can be a cathode electrode for sensing atrial signals and delivering pacing pulses to the atrial myocardium in the target implantation region 4. When the distal housing-based electrode 22 acts as an atrial cathode electrode, the proximal housing-based electrode 24 can serve as a return anode paired with the tip electrode 42 for ventricular pacing and sensing, and can also serve as a return anode paired with the distal housing-based electrode 22 for atrial pacing and sensing.

[0103] As illustrated in the diagram, in some pacing applications, the target implantation region 4 is along the atrial endocardium 18, typically below the AV node 15 and His bundle 5. The dart electrode assembly 12 may at least partially define the height 47 or length of the shaft 40 to penetrate the atrial endocardium 18 in the target implantation region 4, through the central fibrous body 16, and into the ventricular myocardium 14 without penetrating the ventricular endocardial surface 17. When the height 47 or length of the dart electrode assembly 12 is fully advanced into the target implantation region 4, the tip electrode 42 may be positioned within the ventricular myocardium 14, and the distal housing-based electrode 22 may be positioned in close contact with or very close to the atrial endocardium 18. In various examples, the dart electrode assembly 12 may have a total combined height 47 or length of the tip electrode 42 and shaft 40 of approximately 3 mm to approximately 8 mm. The diameter of the shaft 40 may be less than approximately 2 mm and may be approximately 1 mm or less, or even approximately 0.6 mm or less.

[0104] Figure 9 A two-dimensional (2D) ventricular diagram 300 of a patient's heart (e.g., a top-down view) shows the left ventricle 320 and right ventricle 322 in a standard 17-segment view. Figure 300 defines or includes multiple regions 326 corresponding to different areas of the human heart. As shown, regions 326 are numbered from 1 to 17 (e.g., corresponding to 17 segments of a standard 17-segment human heart model, corresponding to 17 segments of the left ventricle of the human heart). Regions 326 of Figure 300 may include the anterior basal region 1, the anterior basal septum region 2, the subbasal septum region 3, the subbasal region 4, the subbasal lateral region 5, the anterior basal lateral region 6, the mid-anterior region 7, the mid-anterior septum region 8, the mid-inferior septum region 9, the mid-inferior region 10, the mid-inferior lateral region 11, the mid-anterior lateral region 12, the anterior vertex region 13, the vertex septum region 14, the vertex inferior region 15, the vertex lateral region 16, and the apex region 17. The inferior and anterior septal regions of the right ventricle 322, as well as the right bundle branch (RBB) 25 and the left bundle branch (LBB) 27, are also shown.

[0105] In some embodiments, any tissue-piercing electrode of this disclosure may be implanted in the base and / or septum region of the left ventricular myocardium of a patient's heart. Specifically, the tissue-piercing electrode may be implanted through the right atrial endocardium and central fibrous body via the Koch's triangle region of the right atrium. Once implanted, the tissue-piercing electrode can be positioned in a target implantation area such as the base and / or septum region of the left ventricular myocardium. Figure 7-8 Referring to Figure 300, the basal region includes one or more of the following: anterior basal region 1, anterior basal septum 2, subbasal septum 3, subbasal region 4, mid-anterior region 7, mid-anterior septum 8, mid-inferior septum 9, and mid-inferior region 10. Referring to Figure 300, the septal region includes one or more of the following: anterior basal septum 2, anterior basal septum 3, mid-anterior septum 8, mid-inferior septum 9, and superior septum 14.

[0106] In some embodiments, when implanted, the tissue-puncturing electrode may be positioned in the baso-septal region of the left ventricular myocardium. The baso-septal region may include one or more of the following: anterior baso-septal region 2, subbaso-septal region 3, anterior baso-septal region 8, and subbaso-septal region 9.

[0107] In some embodiments, when implanted, the tissue-puncturing electrode can be positioned in the superior / posterior basal septum region of the left ventricular myocardium. The superior / posterior basal septum region of the left ventricular myocardium may include a portion of one or more of the subbasal septum region 3 and the middle / inferior septum region 9 (e.g., only the subbasal septum region, only the middle / inferior septum region, or both). For example, the superior / posterior basal septum region may include a region 324 generally illustrated as a dashed boundary. As shown, the dashed boundary indicates the approximate location of the superior / posterior basal septum region, and its shape or size may vary slightly depending on the specific application.

[0108] Figure 10 The diagram depicts a block diagram of a circuit system that, according to one example, may be enclosed within a housing 30 of device 10 to provide functions such as sensing cardiac signals, determining capture and / or delivering pacing therapy, or within the housing of any other medical device described herein. A separate medical device 50 (such as...) Figure 7 The device 10 (as shown) may include some or all of the same components that can be configured in a similar manner. The electronic circuitry enclosed within housing 30 may include software, firmware, and hardware that collaboratively monitor atrioventricular and ventricular electrocardiographic signals, determine whether cardiac system capture has occurred, determine when cardiac therapy is needed, and / or deliver electrical pulses to the patient's heart according to programmed therapy patterns and pulse control parameters. The electronic circuitry may include control circuitry 80 (e.g., including processing circuitry), memory 82, therapy delivery circuitry 84, sensing circuitry 86, and / or telemetry circuitry 88. In some instances, device 10 includes one or more sensors 90 for generating signals related to one or more physiological functions, states, or symptoms of the patient. For example, one or more sensors 90 may include patient activity sensors for determining the need for pacing therapy and / or controlling the pacing rate. In other words, device 10 may include additional sensors 90 for sensing signals from the patient to determine whether and / or control the delivery of electrical stimulation therapy by therapy delivery circuitry 84.

[0109] Power source 98 can provide power as needed to the circuitry of device 10, which includes each of components 80, 82, 84, 86, 88, and 90. Power source 98 may include one or more energy storage devices, such as one or more rechargeable or non-rechargeable batteries. The connections between power source 98 and each of components 80, 82, 84, 86, 88, and 90 (not shown) can be understood from the overall block diagram shown to a person skilled in the art. For example, power source 98 may be coupled to one or more charging circuits included in therapy delivery circuitry 84 to provide power for charging a holding capacitor included in therapy delivery circuitry 84, which is discharged at appropriate times under the control of control circuitry 80 to deliver pacing pulses, for example, according to a dual-chamber pacing mode (such as DDI(R)). Power source 98 may also be coupled to components of sensing circuitry 86 (such as sensing amplifiers, analog-to-digital converters, switching circuitry, etc.), sensor 90, telemetry circuitry 88, and memory 82 to provide power to various circuits.

[0110] Figure 10 The functional blocks shown represent the functions included in device 10 and may include any discrete and / or integrated electronic circuit components that implement analog and / or digital circuitry capable of producing the functions attributed to the medical device 10 described herein. Each component may include processing circuitry systems (such as application-specific integrated circuits (ASICs), electronic circuitry, processors (shared, dedicated, or grouped), and memory) that execute one or more software or firmware programs, combinational logic circuitry, state machines, or other suitable components or combinations of components that provide the described functions. The specific form of software, hardware, and / or firmware used to implement the functions disclosed herein will be determined primarily by the specific system architecture employed in the medical device and the specific detection and therapy delivery methods employed by the medical device.

[0111] Memory 82 may comprise any volatile, non-volatile, magnetic, or electrically non-transitory computer-readable storage medium, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, or any other memory device. Furthermore, memory 82 may comprise a non-transitory computer-readable medium storing instructions that, when executed by one or more processing circuits, cause control circuitry 80 and / or other processing circuitry systems to determine left posterior bundle branch engagement and / or perform single-chamber, dual-chamber, or triple-chamber calibrated pacing therapy (e.g., single-chamber or multi-chamber pacing) or other cardiac therapeutic functions attributed to device 10 (e.g., sensing or delivery therapy). The non-transitory computer-readable medium storing instructions may comprise any of the media listed above.

[0112] The control circuit 80 can communicate, for example, via a data bus with the therapy delivery circuit 84 and the sensing circuit 86 to sense cardiac electrical signals and control the delivery of cardiac electrical stimulation therapy in response to sensed cardiac events (e.g., P waves and R waves, or their absence). The tip electrode 42, the distal housing-based electrode 22, and the proximal housing-based electrode 24 can be electrically coupled to the therapy delivery circuit 84 for delivering electrical stimulation pulses to the patient's heart, and electrically coupled to the sensing circuit 86 for sensing cardiac electrical signals.

[0113] Sensing circuit 86 may include an atrial (A) sensing channel 87 and a ventricular (V) sensing channel 89. A distal housing-based electrode 22 and a proximal housing-based electrode 24 may be coupled to the atrial sensing channel 87 to sense atrial signals, such as P waves associated with atrial myocardial depolarization. In instances including two or more selectable distal housing-based electrodes, sensing circuit 86 may include a switching circuit system for selectively coupling one or more of the available distal housing-based electrodes to a cardiac event detection circuitry system contained in the atrial sensing channel 87. The switching circuit system may include a switch array, switch matrix, multiplexer, or any other type of switching device suitable for selectively coupling components of sensing circuit 86 to selected electrodes. A tip electrode 42 and a proximal housing-based electrode 24 may be coupled to the ventricular sensing channel 89 to sense ventricular signals, such as R waves associated with ventricular myocardial depolarization.

[0114] Each of the atrial sensing channel 87 and the ventricular sensing channel 89 may include a cardiac event detection circuitry for detecting P waves and R waves, respectively, from cardiac electrical signals received by the respective sensing channel. The cardiac event detection circuitry included in each of channels 87 and 89 may be configured to amplify, filter, digitize, and rectify the cardiac electrical signals received from selected electrodes to improve signal quality for detecting cardiac electrical events. The cardiac event detection circuitry within each channel 87 and 89 may include one or more sensing amplifiers, filters, rectifiers, threshold detectors, comparators, analog-to-digital converters (ADCs), timers, or other analog or digital components. The cardiac event sensing thresholds, such as P wave sensing thresholds and R wave sensing thresholds, may be automatically adjusted by each respective sensing channel 87 and 89 under the control of the control circuitry 80, for example, based on a timing period and sensing thresholds stored in memory 82 and / or controlled by the hardware, firmware, and / or software of the control circuitry 80 and / or the sensing circuitry 86, as determined by the control circuitry 80.

[0115] When a cardiac electrical event is detected based on a sensing threshold crossing, sensing circuit 86 can generate a sensed event signal that is transmitted to control circuit 80. For example, atrial sensing channel 87 can generate a P-wave sensed event signal in response to a P-wave sensed threshold crossing. Ventricular sensing channel 89 can generate an R-wave sensed event signal in response to an R-wave sensed threshold crossing. Control circuit 80 can use the sensed event signals to set a pacing escape interval timer that controls the basic time interval used to schedule cardiac pacing pulses. Depending on the specific programmed pacing mode, the sensed event signals can trigger or suppress pacing pulses. For example, a P-wave sensed event signal received from atrial sensing channel 87 can cause control circuit 80 to suppress scheduled atrial pacing pulses and schedule ventricular pacing pulses with a programmed atrioventricular (AV) pacing interval. If an R-wave is sensed before the AV pacing interval expires, the ventricular pacing pulse can be suppressed. If the AV pacing interval is terminated before the control circuit 80 receives the R-wave sensing event signal from the ventricular sensing channel 89, the control circuit 80 can use the therapy delivery circuit 84 to deliver a scheduled ventricular pacing pulse synchronized with the sensed P wave.

[0116] In some instances, device 10 may be configured to deliver a variety of pacing therapies, including bradycardia pacing, cardiac resynchronization therapy, post-shock pacing, and / or tachycardia-related therapies such as ATP. For example, device 10 may be configured to detect non-sinus tachycardia and deliver ATP. Control circuitry 80 may determine cardiac event time intervals, such as the PP interval between consecutive P-wave sensed event signals received from atrial sensing channel 87, the RR interval between consecutive R-wave sensed event signals received from ventricular sensing channel 89, and the PR and / or RP intervals received between P-wave sensed event signals and R-wave sensed event signals. These intervals may be compared to tachycardia detection intervals to detect non-sinus tachycardia. Tachycardia may be detected in a given cardiac chamber based on a threshold number of detected tachycardia detection intervals.

[0117] The therapy delivery circuit 84 may include an atrial pacing circuit 83 and a ventricular pacing circuit 85. Each pacing circuit 83, 85 may include a charging circuit system, one or more charge storage devices (such as one or more low-voltage holding capacitors), an output capacitor, and / or a switching circuit system that controls when the one or more holding capacitors are charged and discharged across the output capacitor to deliver pacing pulses to the pacing electrode vector coupled to the respective pacing circuit 83, 85. The tip electrode 42 and the proximal housing-based electrode 24 may be coupled as a bipolar cathode and anode pair to the ventricular pacing circuit 85 to deliver ventricular pacing pulses, for example, upon the expiration of the AV or VV pacing interval set by the control circuit 80 for providing atrial synchronizing ventricular pacing and a basic lower ventricular pacing rate.

[0118] Atrial pacing circuit 83 can be coupled to distal housing-based electrode 22 and proximal housing-based electrode 24 to deliver atrial pacing pulses. Control circuit 80 can set one or more atrial pacing intervals based on a programmed lower pacing rate or a temporarily lower rate set according to a pacing rate indicated by a rate responsive sensor. If the atrial pacing interval is cut off before a P-wave sensed event signal is received from atrial sensing channel 87, the atrial pacing circuit can be controlled to deliver atrial pacing pulses. Control circuit 80 initiates an AV pacing interval in response to the delivered atrial pacing pulses to provide synchronized multi-chamber pacing (e.g., dual-chamber or triple-chamber pacing).

[0119] The therapy delivery circuit 84 can charge the holding capacitors of the atrial or ventricular pacing circuits 83, 85 to a programmed pacing voltage amplitude and discharge the capacitors for a programmed pacing pulse width, based on control signals received from the control circuit 80. For example, the pacing timing circuit included in the control circuit 80 may include a programmable digital counter, set by the microprocessor of the control circuit 80, to control the basic pacing interval associated with various single-chamber or multi-chamber pacing (e.g., dual-chamber or triple-chamber pacing) modes or anti-tachycardia pacing sequences. The microprocessor of the control circuit 80 can also set the amplitude, pulse width, polarity, or other characteristics of the cardiac pacing pulses based on programmed values ​​stored in memory 82.

[0120] Control parameters for sensing cardiac events and controlling the delivery of pacing therapy, utilized by control circuitry 80, can be programmed into memory 82 via telemetry circuitry 88, which can also be described as a communication interface. Telemetry circuitry 88 includes a transceiver and antenna for communicating with external devices such as programmers or home monitors using radio frequency communication or other communication protocols. Control circuitry 80 can use telemetry circuitry 88 to receive downlink telemetry from external devices and transmit uplink telemetry to external devices. In some cases, telemetry circuitry 88 can be used to transmit and receive communication signals to and from another medical device implanted in the patient.

[0121] The techniques described in this disclosure, including those attributable to IMD 10, device 50, computing device 140, and computing device 160 and / or various constituent components, can be implemented at least in part in hardware, software, firmware, or any combination thereof. For example, aspects of these techniques can be implemented within one or more processors (including one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated or discrete logic circuit systems, and any combination of such components), embodied in a programmer, such as a physician or patient programmer, stimulator, image processing device, or other device. The terms “module,” “processor,” or “processing circuit system” can generally refer to any circuit system, alone or in combination with other logic circuit systems, or any other equivalent circuit system.

[0122] Such hardware, software, and / or firmware may be implemented within the same device or in separate devices to support the various operations and functions described in this disclosure. Furthermore, any described unit, module, or component may be implemented together or individually as discrete but interoperable logical devices. Describing different features as modules or units is intended to highlight different functional aspects and does not necessarily imply that such modules or units must be implemented by separate hardware or software components. Rather, the functionality associated with one or more modules or units may be performed by separate hardware or software components, or integrated into common or separate hardware or software components.

[0123] When implemented in software, the functionality attributable to the systems, apparatus, and techniques described in this disclosure can be embodied in instructions on a computer-readable medium such as RAM, ROM, NVRAM, EEPROM, flash memory, magnetic data storage media, optical data storage media, etc. The instructions can be executed by a processing circuit system and / or one or more processors to support one or more aspects of the functionality described in this disclosure.

[0124] For all purposes, all references and publications cited herein are expressly incorporated herein by reference in their entirety, unless any incorporated aspect directly contradicts this disclosure.

[0125] Unless otherwise stated, all scientific and technical terms used herein have the meanings commonly used in the art. The definitions provided herein are intended to facilitate understanding of certain terms frequently used herein and are not intended to limit the scope of this disclosure.

[0126] Unless otherwise stated, all figures used in the specification and claims to indicate the size, quantity, and physical properties of features are to be understood as being modified by the terms “complete” or “about”. Therefore, unless indicated to the contrary, the numerical parameters shown in the foregoing specification and appended claims are approximations that may vary depending on the desired properties sought by those skilled in the art using the teachings disclosed herein or, for example, within typical ranges of experimental error.

[0127] The numerical ranges listed by endpoints include all numbers included within the range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within the range. In this document, the terms "at most" or "not greater than" a number (e.g., at most 50) include that number (e.g., 50), and the terms "not less than" a number (e.g., not less than 5) include that number (e.g., 5).

[0128] The terms “coupled” or “connected” refer to components being directly connected to each other (in direct contact with each other) or indirectly connected (having one or more components between two components and connecting them). Both terms can be modified by “operationally” and “operably”, and they can be used interchangeably to describe a coupling or connection configured to allow components to interact to perform at least some functions (e.g., a first medical device can be operably coupled to another medical device to send or receive information in the form of data).

[0129] Orientation-related terms, such as “top,” “bottom,” “side,” and “end,” are used to describe the relative position of components and do not imply limitation on the orientation of the embodiments under consideration. For example, embodiments described as having a “top” and a “bottom” also include embodiments in which they rotate in various directions, unless otherwise clearly indicated by the content.

[0130] The references to "one embodiment," "an embodiment," "certain embodiments," or "some embodiments," etc., mean that a particular feature, configuration, composition, or characteristic described in connection with the embodiment is included in at least one embodiment of this disclosure. Therefore, the appearance of these phrases in various places throughout the text does not necessarily refer to the same embodiment of this disclosure. Furthermore, in one or more embodiments, particular features, configurations, compositions, or characteristics may be combined in any suitable manner.

[0131] As used in this specification and the appended claims, unless otherwise expressly stated herein, the singular forms “a,” “an,” and “the” include embodiments having multiple referents. Unless otherwise expressly stated herein, as used in this specification and the appended claims, the term “or” is generally used in its sense to include “and / or.”

[0132] As used in this article, terms such as “have,” “having,” “include,” “including,” “comprise,” and “comprising” are used in their open-ended sense and generally refer to “including but not limited to.” It will be understood that phrases such as “basically composed of” or “composed of” are included within “including.”

[0133] The term "and / or" refers to one or all of the listed elements or a combination of at least two of the listed elements. The phrases "at least one," "including at least one," and "one or more" that follow the list refer to any item in the list and any combination of two or more items in the list.

[0134] Illustrative Examples

[0135] Example 1: A system comprising:

[0136] Electrode device comprising multiple posterior electrodes for monitoring electrical activity from the posterior aspect of the patient; and

[0137] A computing device, comprising a processing circuitry system coupled to the electrode device and configured to:

[0138] The multiple posterior electrodes were used to monitor the patient's cardiac electrical activity during the delivery of cardiac therapy.

[0139] Electrical heterogeneity information (EHI) is generated based on electrical activity monitored during cardiac therapy delivery, and

[0140] The degree of left posterior bundle branch conjunctival fusion is determined based on the generated EHI.

[0141] Example 2: A method comprising:

[0142] Multiple posterior electrodes from the back of the patient are used to monitor the electrical activity of the patient's heart during delivery of cardiac therapy;

[0143] Electrical heterogeneity information (EHI) is generated based on electrical activity monitored during cardiac therapy delivery; and

[0144] The degree of left posterior bundle branch conjunctival fusion is determined based on the generated EHI.

[0145] Example 3: A system or method according to one of Examples 1 to 2, wherein generating EHI based on the monitored electrical activity during delivery of cardiac therapy includes generating an average of alternative posterior electrical activation times monitored by the posterior electrode.

[0146] Example 4: According to the system or method of any one of Examples 1 to 3, determining the degree of left posterior bundle branch engagement based on the generated EHI includes determining that the left bundle branch is sufficiently engaged if the average value of the alternative posterior electrical activation time monitored by the posterior electrode is less than or equal to 30 milliseconds, determining that the left bundle branch is moderately engaged if the average value of the alternative posterior electrical activation time monitored by the posterior electrode is greater than 30 milliseconds and less than 50 milliseconds, or determining that the left bundle branch is insufficiently engaged if the average value of the alternative posterior electrical activation time monitored by the posterior electrode is greater than or equal to 50 milliseconds.

[0147] Example 5: A system or method according to any one of Examples 1 to 4, wherein generating EHI based on the monitored electrical activity during delivery of cardiac therapy includes generating a percentage of alternative early activation electrical activation time less than an early activation threshold monitored by the rear electrode.

[0148] Example 6: The system or method according to Example 5, wherein the early activation threshold is 35 milliseconds.

[0149] Example 7: According to the system or method of one of Examples 5 to 6, determining the degree of left posterior bundle branch engagement based on the generated EHI includes determining that the left bundle branch is sufficiently engaged if the percentage of the alternative early activation electrical activation time is greater than 75%, determining that the left bundle branch is moderately engaged if the percentage of the alternative early activation electrical activation time is greater than or equal to 50% and less than or equal to 75%, or determining that the left bundle branch is insufficiently engaged if the percentage of the alternative early activation electrical activation time is less than 50%.

[0150] Example 8: A system or method according to any one of Examples 1 to 7, wherein the cardiac therapy is an atrial-to-ventricular (VfA) pacing therapy.

[0151] Example 9: A system or method according to any one of Examples 1 to 8, wherein the computing device is further configured to perform or the method further includes adjusting the cardiac therapy to increase the degree of left posterior bundle branch engagement.

[0152] Example 10: A system comprising:

[0153] Electrode device comprising multiple posterior electrodes for monitoring electrical activity from the posterior aspect of the patient; and

[0154] A computing device, comprising a processing circuitry system coupled to the electrode device and configured to:

[0155] The multiple rear electrodes are used to monitor the patient's cardiac electrical activity during the delivery of cardiac pacing therapy.

[0156] The degree of left posterior bundle branch conjunctival fusion is determined based on monitored electrical activity, and

[0157] One or more pacing settings of the cardiac pacing therapy are adjusted based on the determined degree of left bundle branch engagement.

[0158] Example 11: The system according to Example 10, wherein the cardiac pacing therapy includes one or more of atrial-to-ventricular (VfA) pacing therapy, His bundle pacing therapy, and interventricular septal left ventricular endocardial pacing.

[0159] Example 12: A system or method according to any one of Examples 1 to 11, wherein the plurality of posterior electrodes comprises a plurality of surface electrodes positioned in an array near the skin of the posterior torso of the patient.

[0160] This disclosure is provided with reference to illustrative embodiments and is not intended to be limiting. As previously described, those skilled in the art will recognize that various other illustrative applications can utilize the beneficial features of the devices and methods described herein using the techniques described herein. Various modifications to the illustrative embodiments and further embodiments of this disclosure will become apparent in this specification.

Claims

1. A medical system comprising: An electrode device comprising multiple posterior electrodes for monitoring electrical activity from the posterior part of a patient; and A computing device, comprising a processing circuitry system coupled to the electrode device and configured to: The multiple posterior electrodes were used to monitor the patient's cardiac electrical activity during the delivery of cardiac therapy. Electrical heterogeneity information (EHI) is generated based on the electrical activity monitored using the multiple post-electrodes during cardiac therapy delivery. The degree of left posterior bundle branch engagement is determined based on the EHI generated according to the electrical activity monitored using the plurality of posterior electrodes.

2. The system of claim 1, wherein generating EHI based on the monitored electrical activity during delivery of cardiac therapy comprises generating an average of alternative posterior electrical activation times monitored by the posterior electrode.

3. The system of claim 2, wherein determining the degree of left posterior bundle branch engagement based on the generated EHI comprises: If the average value of the alternative posterior electrical activation time monitored by the posterior electrode is less than or equal to 30 milliseconds, then the left bundle branch is determined to be adequately engaged; if the average value of the alternative posterior electrical activation time monitored by the posterior electrode is greater than 30 milliseconds and less than 50 milliseconds, then the left bundle branch is determined to be moderately engaged; or if the average value of the alternative posterior electrical activation time monitored by the posterior electrode is greater than or equal to 50 milliseconds, then the left bundle branch is determined to be inadequately engaged.

4. The system of claim 1, wherein generating EHI based on the monitored electrical activity during delivery of cardiac therapy comprises generating a percentage of alternative early activation electrical activation time less than an early activation threshold monitored by the rear electrode.

5. The system of claim 4, wherein the early activation threshold is at most 35 milliseconds.

6. The system of claim 4, wherein determining the degree of left posterior bundle branch engagement based on the generated EHI comprises: If the percentage of the alternative early activation electrical activation time is greater than 75%, then the left bundle branch is determined to be adequately engaged; if the percentage of the alternative early activation electrical activation time is greater than or equal to 50% and less than or equal to 75%, then the left bundle branch is determined to be moderately engaged; or if the percentage of the alternative early activation electrical activation time is less than 50%, then the left bundle branch is determined to be inadequately engaged.

7. The system according to any one of claims 1 to 6, wherein the cardiac therapy is an atrial-to-ventricular (VfA) pacing therapy.

8. The system according to any one of claims 1 to 6, wherein the computing device is further configured to adjust the cardiac therapy to increase the degree of left posterior bundle branch engagement.

9. The system according to any one of claims 1 to 6, wherein the plurality of posterior electrodes comprises a plurality of surface electrodes positioned in an array near the skin of the posterior part of the patient's torso.

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