The benefits of cardiac conduction system therapy are confirmed.

Abstract

This article describes systems and methods for determining whether cardiac conduction system pacing therapy may be beneficial and / or for determining how close or far a cardiac conduction system block may be using external cardiac signals. For this purpose, one or more left-sided measures can be generated based on left-sided alternative cardiac electrical activity measured using multiple left external electrodes to produce information on electrical heterogeneity.

Description

[0001] This disclosure relates to systems and methods for determining the therapeutic benefits of using multiple external electrodes on the cardiac conduction system.

[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 the ventricles can be selected to improve the coordination and efficiency of ventricular contractions.

[0004] IMDS can be described as delivering one or both of conventional pacing therapy and cardiac conduction system pacing therapy. Conventional or traditional pacing therapy can be described as delivering pacing pulses to myocardial tissue that is not part of the patient's cardiac conduction system, such that electrical activation propagates from one myocardial cell to another (also known as "cell-to-cell"). For example, conventional pacing therapy can deliver pacing pulses directly to the muscular cardiac tissue that needs to be depolarized to provide cardiac contraction. For example, conventional left ventricular pacing therapy can utilize an implanted left ventricular (LV) coronary sinus lead that extends through one or more veins, the vena cava, the right atrium, and into the coronary sinus to reach a region adjacent to the free wall of the left ventricle of the heart, in order to deliver pacing pulses to the myocardial tissue of the free wall of the left ventricle.

[0005] Cardiac conduction system pacing therapy can be described as delivering pacing pulses into the cardiac conduction system. More specifically, cardiac conduction system pacing therapy can involve one or more parts of the cardiac conduction system, such as the left bundle branch, His bundle, atrioventricular node, right bundle branch, etc. For example, an atrial-to-ventricular (VfA) lead can deliver pacing pulses directly to the left bundle branch of the cardiac conduction system, allowing the pulse to propagate along the left bundle branch and Purkinje fibers, thereby initiating depolarization of cardiac tissue near the pulse (e.g., myocardial tissue of the left ventricle).

[0006] In addition to the implantable medical device itself, the system used for implanting the medical device may also include a workstation or other devices. In some cases, these other devices assist physicians or other technicians in placing the intracardiac lead at a specific location on the heart. In some cases, the device provides the physician with information about the heart's electrical activity and the location of the intracardiac lead. The device can perform functions similar to those of the medical device, including delivering electrical stimulation to the heart and sensing cardiac depolarization. In some cases, the device may include equipment for obtaining an electrocardiogram (ECG) via electrodes on the patient's surface or skin. More specifically, the patient may have multiple electrodes on an ECG belt or vest around the patient's torso. After the belt or vest has been secured to the torso, the physician can perform a series of tests to assess the patient's cardiac response. The assessment process may include detecting a baseline rhythm in which no electrical stimulation is delivered to the cardiac tissue and another rhythm after electrical stimulation is delivered to the cardiac tissue.

[0007] ECG electrodes placed on the surface of a patient's body can be used for a variety of therapeutic purposes (e.g., cardiac resynchronization therapy) and include optimization of lead placement, pacing parameters, etc., based on one or more metrics derived from signals captured by the ECG electrodes. Summary of the Invention

[0008] The exemplary systems and methods described herein can be configured to help a user (e.g., physician, clinician, doctor, etc.) determine whether a patient can benefit from cardiac conduction system therapy before implanting and configuring a cardiac therapy device to perform one or both of cardiac conduction system pacing therapy and conventional cardiac pacing therapy. Therefore, the illustrative systems and methods can be performed during the inherent activation of the patient's heart (e.g., without any cardiac therapy being delivered to the patient and allowing the patient's heart to beat naturally). Further, the systems and methods can be described as non-invasive. For example, the systems and methods may not use implantable devices such as leads, probes, sensors, catheters, etc., to assess whether a patient can benefit from cardiac conduction system therapy or to determine the location or extent of cardiac conduction system blockage. Instead, the systems and methods can use electrical measurements obtained non-invasively using, for example, multiple external electrodes attached to the patient's skin around the torso.

[0009] An illustrative system may include an electrode device and a computing device coupled to the electrode device. The electrode device may include a plurality of external electrodes positioned close to the patient's skin, and the plurality of external electrodes may include a plurality of left external electrodes positioned on the left side of the patient's torso. The computing device may include a processing circuitry system and is configured to use the plurality of external electrodes of the electrode device to measure an alternative cardiac electrical activation time during intrinsic activation of the patient's heart. The alternative cardiac electrical activation time may represent cardiac tissue depolarization propagating through the patient's torso. The computing device may be further configured to generate electrical heterogeneity information (EHI) based on the measured alternative cardiac electrical activation time. The EHI may include one or more left metrics generated based on the left activation time of the alternative cardiac electrical activation time measured using the plurality of left external electrodes. The computing device may be further configured to determine, at least based on the one or more left metrics, whether cardiac conduction system pacing therapy would be beneficial to the patient.

[0010] An illustrative method may include measuring the alternative cardiac electrical activation time using multiple external electrodes positioned close to the patient's skin during the inherent activation of the patient's heart. The multiple external electrodes may include multiple left external electrodes positioned on the left side of the patient's torso, and the alternative cardiac electrical activation time may represent cardiac tissue depolarization propagating through the patient's torso. The illustrative method may further include generating electrical heterogeneity information (EHI) based on the measured alternative cardiac electrical activation time. The EHI may include one or more left-side metrics generated based on the left-side activation time of the alternative cardiac electrical activation time measured using the multiple left external electrodes. The illustrative method may further include determining, at least based on said one or more left-side metrics, whether cardiac conduction system pacing therapy would be beneficial to the patient.

[0011] An illustrative system may include an electrode device and a computing device coupled to the electrode device. The electrode device may include a plurality of external electrodes positioned close to the patient's skin, and the plurality of external electrodes may include a plurality of left external electrodes positioned on the left side of the patient's torso. The computing device may include a processing circuitry system and is configured to use the plurality of external electrodes of the electrode device to measure alternative cardiac electrical activation time during the intrinsic activation of the patient's heart. The alternative cardiac electrical activation time may represent cardiac tissue depolarization propagating through the patient's torso. The computing device may be further configured to generate electrical heterogeneity information (EHI) based on the measured alternative cardiac electrical activation time. The EHI may include one or more left metrics generated based on the left activation time of the alternative cardiac electrical activation time measured using the plurality of left external electrodes. The computing device may be further configured to determine, at least based on the one or more left metrics, whether cardiac conduction system block is closer to a proximal region than a distal region along the patient's cardiac conduction network. The patient's cardiac conduction network may extend from a proximal region near the patient's sinoatrial node or atrioventricular node to a distal region near the patient's Purkinje fibers.

[0012] An illustrative system may include an electrode device, a display, and a computing device coupled to the electrode device and the display. The electrode device may include a plurality of external electrodes positioned close to the patient's skin, and the plurality of external electrodes may include a plurality of left external electrodes positioned on the left side of the patient's torso. The display may include a graphical user interface to present information to help the user assess whether the patient will benefit from cardiac conduction system pacing therapy. The computing device may include processing circuitry and be configured to: allow the user to initiate a cardiac conduction system pacing therapy benefit determination on the graphical user interface, and in response to the user initiating the cardiac conduction system pacing therapy benefit determination, measure the alternative cardiac electrical activation time using the plurality of external electrodes of the electrode device during the inherent activation of the patient's heart. The alternative cardiac electrical activation time may represent cardiac tissue depolarization propagating through the patient's torso. The computing device may be further configured to generate electrical heterogeneity information (EHI) based on the measured alternative cardiac electrical activation time. The EHI may include one or more left-side metrics generated based on the left-side activation time of the alternative cardiac electrical activation time measured using the plurality of left external electrodes. The computing device can be further configured to display on a graphical user interface an indication of whether pacing therapy of the cardiac conduction system would be beneficial to the patient, based at least on one or more of the left-hand measurements.

[0013] In at least one embodiment, illustrative systems and methods can determine the percentage of late-activating electrodes on the left side of the body (e.g., external electrodes positioned on the patient's skin in an array around the left side of the spine from the sternum at the front of the patient to the back of the patient) to estimate the degree of left ventricular activation delay during the intrinsic rhythm (e.g., due to left bundle branch block (LBBB)). For example, the percentage of external electrodes on the patient's left side that monitor alternative cardiac activation after a certain time threshold (e.g., 40 milliseconds, 50 milliseconds, etc.) can be expressed as a percentage, relative to the earliest detected alternative cardiac activation divided by the total number of external electrodes on the left side. If the percentage is greater than or equal to a percentage threshold (e.g., 40%, 50%, 60%, etc.) and / or the mean activation time of the left lateral conduction system (LVAT) is greater than or equal to a certain threshold (e.g., 40 ms, 50 ms, 60 ms, etc.), the block in the left bundle may be closer to the proximal side, and such patients can be corrected with proximal conduction system pacing. Therefore, these patients would be candidates to attempt conduction system pacing during implantation (e.g., before routine pacing of cardiac regions outside the cardiac conduction system, such as myocardial tissue). Conversely, if the percentage is less than a percentage threshold and / or the LVAT is less than a certain threshold, the block in the left bundle may be closer to the distal side, which may not be corrected with proximal conduction system pacing.

[0014] Therefore, descriptive systems and methods can be provided to provide screening systems to determine which patients may benefit from cardiac conduction system pacing based on the inherent ECG and the metrics derived from it prior to any invasive procedure for implanting a cardiac conduction system pacing device.

[0015] The above overview is not intended to describe every embodiment or implementation of this disclosure. A more complete understanding will become apparent and readily understood by taking into account the accompanying drawings and the following detailed description and claims. Attached Figure Description

[0016] Figure 1 This is a diagram of an exemplary system that includes an electrode device, a display device, and a computing device.

[0017] Figure 2-3 This is a diagram of an exemplary external electrode device for monitoring electrical activity (e.g., trunk surface potential, surrogate cardiac electrical activation time, etc.).

[0018] Figure 4A The cardiac conduction network of a patient with cardiac conduction system block located between the atrioventricular node and His bundle is depicted.

[0019] Figure 4B The cardiac conduction network of a patient with cardiac conduction system block located in the left branch is depicted.

[0020] Figure 5A This is a block diagram illustrating a method for determining whether a patient can benefit from cardiac conduction system pacing therapy.

[0021] Figure 5B yes Figure 5A The detailed block diagram of the illustrative method described in the diagram.

[0022] Figure 6A Bar graphs showing the intrinsic cardiac electrical data of patients who later underwent His bundle pacing.

[0023] Figure 6B The diagrams show intrinsic or baseline activation in two patients, as well as anterior and posterior activation during His bundle pacing.

[0024] Figure 7 This is a conceptual diagram of an illustrative cardiac therapy system that includes an intracardiac medical device implanted in the patient's heart and a separate medical device positioned outside the patient's heart.

[0025] Figure 8 yes Figure 7 An enlarged conceptual diagram of the anatomy of an intracardiac medical device and a patient's heart.

[0026] Figure 9 This is 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.

[0027] Figure 10 It is possible to enclose, for example 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

[0028] In the following detailed description of illustrative embodiments, reference is made to the accompanying drawings, which form a part of the detailed description, and specific embodiments that can be practiced are illustrated by way of illustration in the drawings. 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.

[0029] Please refer to Figure 1-10Describing illustrative systems and methods. It will be apparent to those skilled in the art that elements or processes from one embodiment can be combined with elements or processes from other embodiments, and that possible embodiments of such systems and methods 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 recognized that the embodiments described herein may include many elements that are not necessarily shown to scale. Still further, it will be recognized that the timing of the processes and the size and shape of the various elements described herein can be modified but still fall within the scope of this disclosure; however, certain timings, one or more shapes and / or sizes, or element types may be preferred over others.

[0030] Multiple external electrodes positioned on or around the patient's surface or skin can be used to measure or monitor multiple electrocardiogram (ECG) signals (e.g., trunk surface potential). ECG signals can be used to assess a patient's cardiac health to determine if the patient can benefit from cardiac conduction pacing therapy and / or another cardiac treatment, and to determine the location or relative position of a cardiac conduction system block. As described herein, ECG signals can be acquired or obtained non-invasively, as implantable electrodes, for example, may not be used to measure ECG signals. Furthermore, ECG signals can be used to determine cardiac electrical activation time, which can be used to generate various metrics (e.g., electrical heterogeneity information) that a user (e.g., a physician) can use to determine if a patient can benefit from cardiac pacing therapy, such as cardiac conduction system pacing therapy and / or conventional pacing therapy.

[0031] Various illustrative systems, methods, and graphical user interfaces can be configured to noninvasively assist users (e.g., physicians) in assessing cardiac health, determining the location of cardiac conduction blockages, and determining whether a patient can benefit from cardiac conduction pacing therapy and / or other types of cardiac therapy using electrode devices, display devices, and computing devices containing 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.

[0032] The electrode device 110 shown in the figure includes a plurality of electrodes incorporated or contained within a bandage wrapped around the chest or torso of the patient 14. 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. Illustrative electrode devices 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 in U.S. Provisional Patent Application Serial No. 62 / 957,449, filed January 6, 2020, entitled “Bioelectric Sensor Device and Methods,” each of which is incorporated herein by reference in its entirety. Further reference will be made to… Figure 2-3 A more detailed description of the illustrative electrode device 110.

[0033] Although not described herein, the illustrative system 100 may further include an imaging device. The imaging device can be any type of imaging device configured to non-invasively image or provide an image of at least a portion of a patient. For example, in addition to non-invasive tools such as contrast solutions, the imaging device may provide an image of the patient without using any components or parts that may be located within the patient's body. It should be understood that the illustrative systems, methods, and interfaces described herein may further utilize the imaging device to provide non-invasive assistance to a user (e.g., a physician) to position or place one or more pacing electrodes near a patient's heart in conjunction with a cardiac therapy configuration.

[0034] For example, illustrative systems and methods can provide image-guided navigation for navigating leads, including electrodes, leadless electrodes, wireless electrodes, catheters, etc., within a patient's body, while also providing non-invasive cardiac therapy configurations, including determining effective or optimal pre-excitation intervals, such as the AV interval and VV interval. Illustrative systems and methods using imaging devices and / or electrode devices can be described in the following documents: U.S. Patent No. 9,877,789B2, issued January 30, 2018 by Ghosh; U.S. Patent No. 10,251,555B2, issued April 9, 2019 by Ghosh et al.; U.S. Patent No. 9,924,884B2, issued March 27, 2018 by Ghosh et al.; and U.S. Patent No. 10,064,567B2, issued September 4, 2018 by Ghosh et al.

[0035] The imaging device can be configured to capture X-ray images and / or any other alternative imaging modalities. For example, the imaging device can be configured to capture images or image data using isocentric fluoroscopy, biplane fluoroscopy, ultrasound, computed tomography (CT), multi-slice computed tomography (MSCT), magnetic resonance imaging (MRI), high-frequency ultrasound (HIFU), optical coherence tomography (OCT), intravascular ultrasound (IVUS), two-dimensional (2D) ultrasound, three-dimensional (3D) ultrasound, four-dimensional (4D) ultrasound, intraoperative CT, intraoperative MRI, etc. Furthermore, it should be understood that the imaging device can be configured to capture multiple consecutive images (e.g., sequentially) to provide video frame data. In other words, multiple images captured by the imaging device over time can provide video frame data or motion picture data. Exemplary systems employing ultrasound can be found in U.S. Patent Application Publication No. 2017 / 0303840, entitled "Noninvasive Assessment of Cardiac Resynthesis Therapy" by Stadler et al. Additionally, images can be obtained and displayed in two, three, or four dimensions. In a more advanced form, four-dimensional surface rendering of the heart or other areas of the body can be achieved by incorporating cardiac data or other soft tissue data from images captured via MRI, CT, or echocardiography modalities. Image datasets from mixed modalities, such as positron emission tomography (PET) combined with CT or single-photon emission computed tomography (SPECT) combined with CT, can also provide functional image data overlaid on anatomical data, for example, for navigating implanted devices to target locations within the heart or other areas of interest.

[0036] Systems and / or imaging devices that can be used in conjunction with the illustrative systems and methods described herein are described in U.S. Patent Application Publication No. 2005 / 0008210, published January 13, 2005, by Evron et al.; U.S. Patent Application Publication No. 2006 / 0074285, published April 6, 2006, by Zakh et al.; U.S. Patent No. 8,731,642, published May 20, 2014, by Zakh et al.; U.S. Patent No. 8,861,830, published October 14, 2014, by Brada et al.; U.S. Patent No. 6,980,675, published December 27, 2005, by Evron et al.; and Okerlun et al. U.S. Patent No. 7,286,866, issued October 23, 2007 by d et al.; U.S. Patent No. 7,308,297, issued December 11, 2011 by Reddy et al.; U.S. Patent No. 7,308,299, issued December 11, 2011 by Burrell et al.; U.S. Patent No. 7,321,677, issued January 22, 2008 by Evron et al.; U.S. Patent No. 7,346,381, issued March 18, 2008 by Okerlund et al.; U.S. Patent No. 7,454,248, issued November 18, 2008 by Burrell et al.; and U.S. Patent No. 7,454,248, issued November 18, 2008 by Vass et al. U.S. Patent No. 7,499,743, issued March 3, 2009; U.S. Patent No. 7,565,190, issued July 21, 2009 by Okerlund et al.; U.S. Patent No. 7,587,074, issued September 8, 2009 by Zakh et al.; U.S. Patent No. 7,599,730, issued October 6, 2009 by Hunter et al.; U.S. Patent No. 7,613,500, issued November 3, 2009 by Vass et al.; U.S. Patent No. 7,742,629, issued June 22, 2010 by Zakh et al.; and U.S. Patent No. 7,742,629, issued June 29, 2010 by Okerlund et al. U.S. Patent No. 7,747,047, Evron et al., U.S. Patent No. 7,778,685, issued August 17, 2010, Vass et al., U.S. Patent No. 7,778,686, issued August 17, 2010, Okerlund et al., U.S. Patent No. 7,813,785, issued October 12, 2010, Vass et al., U.S. Patent No. 7,996,063, issued August 9, 2011, Hunter et al., U.S. Patent No. 8,060,185, issued November 15, 2011, and Verard et al., U.S. Patent No. 8,401,616, issued March 19, 2013.

[0037] Computing device 140 and remote computing device 160 may each include display devices 130 and 170, respectively, which can be configured to display and analyze data, such as electrical signals (e.g., electrocardiogram data), electrical activation time, electrical heterogeneity information, etc. For example, one or more measures of a single cardiac cycle or heartbeat among multiple cardiac cycles or heartbeats represented by electrical signals collected or monitored by electrode device 110 can be analyzed and evaluated. These measures may include alternative cardiac electrical activation time and electrical heterogeneity information that may be related to determining the location or relative position of cardiac conduction system blockage within the patient's cardiac conduction network and determining whether the patient will benefit from one or more different types of cardiac therapies, such as cardiac conduction system pacing therapy. Furthermore, such alternative cardiac electrical activation time and electrical heterogeneity information may also be related to the therapeutic nature of one or more cardiac therapy-related parameters, such as pacing parameters, lead positions, etc., and therefore may be useful for their adjustment. More specifically, for example, one or more measures of the QRS complex in a single cardiac cycle can be assessed, such as QRS onset, QRS deviation, QRS peak, electrical heterogeneity information (EHI), electrical activation time relative to the earliest activation time, percentage of late left activation time relative to left activation time, standard deviation of left ventricular or thoracic electrical activation time (LVED), standard deviation of activation time (SDAT), mean left ventricular or thoracic alternative cardiac electrical activation time (LVAT), QRS duration (e.g., the interval between QRS onset and QRS deviation), difference between mean left alternative activation time and mean right alternative activation time, relative or absolute QRS morphology, 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. Furthermore, each of the one or more measures can be location-specific. For example, some measures can be calculated based on signals recorded or monitored from electrodes located around selected areas of the patient (e.g., the patient's left side, the patient's right side, etc.).

[0038] 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, a tablet computer, a mobile device, and a cellular phone. 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, for example, for analyzing multiple electrical signals captured by the electrode device 110, for determining QRS start, QRS offset, median, mode, average, peak or maximum, trough or minimum, for determining electrical activation time, for driving a graphical user interface configured to non-invasively help a user determine whether a patient can benefit from cardiac conduction system pacing therapy and / or another cardiac therapy, and for driving a configured... A graphical user interface (GUI) configured to non-invasively help users determine the location or relative position of a blockage in the cardiac conduction system, and to drive a GUI configured to non-invasively help users configure 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 four-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, heart rate adaptive settings, and performance, etc.

[0039] 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 configuration information related to cardiac therapy delivered by a cardiac therapy device, such as, for example, an implantable medical device.

[0040] Although input device 142 is a keyboard and input device 162 is a touchscreen as depicted, 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.). Similarly, display devices 130 and 170 may include any device capable of displaying information to a user, such as graphical user interfaces 132 and 172. This information may include electrode status information, graphical representations of electrical activation, indications of whether a patient can benefit from cardiac conduction system pacing therapy and / or another cardiac therapy, the location of possible cardiac conduction system blocks within the patient's cardiac conduction network, multiple signals from external electrodes on one or more heartbeats, QRS complexes, 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 anatomy of the human heart, images or graphical depictions of the patient's heart, graphical depictions of the location of one or more electrodes, graphical depictions of the human torso, images or graphical depictions of the patient's torso, graphical depictions of the patient's cardiac conduction network and any cardiac conduction system blocks located therein, 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, touchscreens, cathode ray tube displays, etc.

[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 used to perform 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 functions 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 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 / or interfaces can be described as being implemented by logic (e.g., object code) encoded in one or more non-transitory media, said logic including 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] The computing device 140 and the remote computing device 160 can be, for example, any fixed or mobile computer system (e.g., a controller, microcontroller, personal computer, microcomputer, tablet computer, etc.). The exact configuration of the computing device 140 and the 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, the digital file 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 the computing device 140 and the remote computing device 160 described herein. Furthermore, as described herein, the user-readable format of the 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, display, 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 intended for implementing the processes described herein should not be limited to the scope of the systems, processes, or programs described herein (e.g., the functions provided by such systems, processes, or programs). Further, additional illustrative systems, methods, and apparatuses that may be used in conjunction with this disclosure are described in U.S. Provisional Patent Application Serial No. 62 / 913,002, filed October 9, 2019, entitled "Systems, Methods, and Devices for Determining Cardiac Condition".

[0046] The illustrative electrode device 110 can be configured to measure the surface potential of the patient 14's body and, more specifically, the surface potential of the patient 14's torso. For example... Figure 2 As shown, the illustrative electrode device 110 may include an external electrode 112, an array or collection of strips 113, and an interface / amplifier circuitry system 116. The electrode 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 14 such that the electrode 112 surrounds the patient's heart. As further shown, the electrode 112 may be positioned around the circumference of the patient 14, including posterior, lateral, posterolateral, anterolateral, and anterior positions of the patient 14's torso.

[0047] The illustrative electrode device 110 can be further configured to measure or monitor at least one or both sounds from the patient 14. For example... Figure 2 As shown, the illustrative electrode device 110 may include an array or collection 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 14 such that the acoustic sensors 120 surround the patient's heart. As further shown, the acoustic sensors 120 may be positioned around the circumference of the patient 14, including posterior, lateral, posterolateral, anterolateral, and anterior positions of the patient 14'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 can be electrically coupled to computing device 140 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 14. 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 part of or within a patch, vest, and / or other means of securing electrodes 112 and acoustic sensors 120 to the torso of patient 14. Furthermore, in other embodiments, one or both of electrode 112 and acoustic sensor 120 may be part of or located within two material segments or two patches. One of these patches may be located on the anterior side of the patient 14's torso (to monitor, for example, electrical signals representing the anterior side of the patient's heart, measure the surrogate cardiac electrical activation time representing the anterior side of the patient's heart, monitor or measure sound on the anterior side of the patient, etc.), and the other patch may be located on the posterior side of the patient 14's torso (to monitor, for example, electrical signals representing the posterior side of the patient's heart, measure the surrogate cardiac electrical activation time representing the posterior side of the patient's heart, monitor or measure sound on the posterior side of the patient, etc.). Furthermore, in other embodiments, one or both of electrode 112 and acoustic sensor 120 may be arranged in top and bottom rows extending from the anterior side of the patient 14 through the left side of the patient 14 to the posterior side of the patient 14. Furthermore, in other instances, one or both of the electrode 112 and the acoustic sensor 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 areas.

[0050] Electrodes 112 can be configured to surround the heart of patient 14 and record or monitor electrical signals associated with cardiac depolarization and repolarization after the signal has propagated through the torso of patient 14. Each electrode in 112 can be used in a monopolar configuration to sense the torso surface potential 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 may be distributed in an array that extends all the way around or completely around the patient 14. Instead, the electrodes 112 and acoustic sensors 120 may be arranged in an array that extends only around a portion or partially around the patient 14. 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 near the right side (including the posterior and anterior regions of the patient's right side).

[0052] The computing device 140 can record and analyze the torso surface potential signal sensed by the electrode 112 and the sound signal sensed by the acoustic sensor 120, which are amplified / modulated by the interface / amplifier circuitry system 116. The computing device 140 can be configured to analyze the electrical signals from the electrode 112 to provide electrocardiogram (ECG) signals, information, or data from the patient's heart, as will be further described herein. The computing device 140 can be configured to analyze the signals from the electrode 112 to provide alternative cardiac electrical activation data, such as alternative cardiac electrical activation time, which, for example, represents the actual or local electrical activation time of one or more regions of the patient's heart, as will be further described herein. Measurement of activation time can be performed by selecting an appropriate reference point (e.g., peak, minimum, minimum slope, maximum slope, zero crossover point, threshold crossover point, etc. of the near-field or far-field EGM) and measuring the time between the onset of cardiac depolarization (e.g., the onset of the QRS complex) and said appropriate reference point (e.g., within electrical activity). The activation time between the start of the QRS complex (or peak Q wave) and the reference point can be referred to as the q-LV time. In at least one embodiment, the earliest QRS start from all multiple electrodes can be used as the starting point for each activation time of each electrode, and the maximum slope after the start of the QRS complex can be used as the ending point for each activation time of each electrode. The computing device 140 can be configured to analyze electrical signals from the acoustic sensor 120 to provide acoustic 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 can be configured to provide graphical user interfaces 132, 172 that depict various information related to electrode device 110 and data collected or sensed using electrode device 110. For example, graphical user interfaces 132, 172 can depict ECG data including QRS complexes obtained using electrode device 110 and acoustic data including 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 to evaluate and configure cardiac therapies delivered to the patient.

[0054] Furthermore, the electrode device 110 may further include, for example, reference electrodes and / or drive electrodes positioned around the lower torso of the patient 14, 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. Further, the electrode device 110 may use three tail-end reference electrodes (e.g., instead of the standard reference used in the Wilson Central Terminal) to obtain a “true” monopolar signal with less noise by averaging the three tail-end positioned reference signals.

[0055] Figure 3 Another illustrative electrode device 110 is shown, comprising multiple electrodes 112 and multiple acoustic sensors 120. The electrodes are configured to surround the heart of a patient 14 and record or monitor electrical signals associated with cardiac depolarization and repolarization after the signal has propagated through the torso of the patient 14. The acoustic sensors are configured to surround the heart of the patient 14 and record or monitor sound signals associated with the heart after the signal has propagated through the torso of the patient 14. The electrode device 110 may comprise a vest 114 to which the multiple electrodes 112 and multiple acoustic sensors 120 may be attached, or the electrodes 112 and acoustic sensors 120 may be coupled to the vest. In at least one embodiment, the multiple electrodes 112 or an array of the electrodes may be used to collect electrical information, for example, alternative to cardiac electrical activation time. Similar to... Figure 2 Electrode equipment 110, Figure 3The 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 14, including, for example, posterior, lateral, posterolateral, anterolateral, and anterior positions of the patient 14's torso.

[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 14. 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 14. In some instances, approximately 25 to approximately 256 electrodes 112 and approximately 25 to approximately 256 acoustic sensors 120 may be distributed around the torso of patient 14, although other configurations may have more or fewer electrodes 112 and more or fewer acoustic sensors 120.

[0057] The illustrative systems and methods can be used to provide noninvasive assistance to users in the assessment of a patient's cardiac health status and / or in the assessment and configuration of cardiac treatments currently being delivered to the patient (e.g., via implantable medical devices for pacing therapy, via LVAD, etc.). Furthermore, 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 embodiments, computing device 140 can be operatively wirelessly coupled to remote computing device 160, as depicted by the wireless signal lines emanating therebetween. Alternatively, in contrast to wireless connectivity, one or more of computing device 140 and remote computing device 160 can be operatively coupled via a single or wired electrical connection.

[0058] The illustrative systems and methods described herein can provide users (e.g., clinicians, physicians, etc.) with useful tools to determine whether a patient will benefit from cardiac conduction system pacing therapy and / or another cardiac therapy. Furthermore, the illustrative systems and methods described herein can provide users with useful tools to determine the location, or relative location, of a cardiac conduction block within a patient's cardiac conduction network. For example, the illustrative systems and methods can determine how close or far the cardiac conduction block is located along the patient's cardiac conduction network. The location of the cardiac conduction block can help determine whether cardiac conduction system pacing therapy and / or another cardiac therapy can successfully treat the patient.

[0059] Figures 4A-4BThe patient's cardiac conduction network 200 is depicted. As shown, the cardiac conduction network 200 extends from a proximal region 222 to a distal region 224. The cardiac conduction network 200 includes specialized cellular networks comprising the left and right bundle branches, as well as a highly branched specialized Purkinje fiber network that facilitates the rapid propagation of electrical activation across the ventricles, potentially resulting in highly synchronized cardiac activation. The cardiac conduction system is part of a natural electrical conduction pathway extending from the sinoatrial node 230 to the ventricles via the atrioventricular node 232. Furthermore, an electrical impulse that triggers depolarization of the patient's myocardial tissue to effectively "beat" travels from the sinoatrial node 230 through the cardiac conduction network 200 to the Purkinje fibers 239.

[0060] As described herein, the proximal region 222 of the cardiac conduction network 200 may include the sinoatrial node 230 and the atrioventricular node 232 and the connecting pathway between them, and the distal region 224 of the cardiac conduction network 200 may include the right bundle branch 238, the left posterior bundle 236, and the Purkinje fiber 239. Specifically, the most distal region of the cardiac conduction network 200 may be the terminal portion of the Purkinje fiber 239, and the most proximal region of the cardiac conduction network 200 may be the sinoatrial node 230. Therefore, the cardiac conduction network 200 can be described as extending from the sinoatrial node 230 to the Purkinje fiber 239.

[0061] exist Figure 4A In this context, cardiac conduction block 240 is located precisely distal to the atrioventricular node 232, but prior to the His bundle 234 branching into the left and right bundles. Therefore, cardiac conduction block 240 can be described as being located relatively close along the cardiac conduction network 220. Using illustrative systems and methods as further described herein, one or more electrical heterogeneity measures can be determined, indicating when cardiac conduction block 240 is located as described herein. Figure 4A The large area 242 in the left ventricle is delayed when the location is shown. Therefore, cardiac conduction block 240 can be a good candidate for cardiac conduction pacing therapy because, for example, cardiac conduction pacing therapy can be delivered to a location or position within the cardiac conduction system distal to cardiac conduction block 240. For example, cardiac conduction pacing therapy can be delivered to either the His bundle 234 or one of the right and left branches.

[0062] exist Figure 4B In this context, cardiac conduction block 241 is located along the left branch, just distal to the left posterior branch. Therefore, cardiac conduction block 241 can be described as being located relatively distally along the cardiac conduction network 220. Using illustrative systems and methods as further described herein, one or more electrical heterogeneity measures can be determined, indicating when cardiac conduction block 241 is located as follows: Figure 4BThe large area 243 in the left ventricle is delayed when the location is shown. Therefore, cardiac conduction block 241 may not be a good candidate for cardiac conduction pacing therapy because, for example, cardiac conduction pacing therapy may not be located further away than cardiac conduction block 241, and if cardiac conduction pacing therapy is located proximal to cardiac conduction block 241 (e.g., at His bundle 234), any such cardiac conduction pacing therapy can be blocked or stopped by cardiac conduction block 241. Therefore, when comparing Figures 4A-4B When cardiac conduction system block 240 or 241 occurs, cardiac conduction system pacing therapy may be used, and the more proximal cardiac conduction system block 240 may be more effective than... Figure 4B The blockage in the cardiac conduction system on the more distal side is more likely to be corrected.

[0063] Figure 5A This document describes an illustrative method 400 for determining whether pacing therapy of the cardiac conduction system is beneficial. As illustrated, method 400 includes monitoring 410 electrical activity to generate multiple electrical signals (e.g., ECG or cardiac signals). Electrical activity can be monitored during the patient's inherent heart rhythm without delivery of any cardiac therapy. Therefore, method 400 can be performed prior to the implantation of any implantable cardiac therapy device. For example, method 400 can be performed during the initial consultation prior to any invasive surgery to treat the current condition. Additionally, as described herein, using multiple external electrodes to monitor electrical activity 410 is a non-invasive procedure because, for example, the external electrodes are attached to the patient's skin, unlike the insertion or implantation of any electrodes to obtain electrical activity or data. However, additionally, if an implantable cardiac therapy device has already been implanted in the patient, method 400 can be performed to disable (or "turn off") any cardiac therapy provided by the implantable cardiac therapy device.

[0064] According to various embodiments, multiple electrodes are used to monitor the electrical activity of 410. The multiple electrodes may be similar to those described herein. Figure 1-3 The straps or vests contain external surface electrodes. Each electrode can be positioned or arranged around the patient's torso to monitor electrical activity (e.g., acquire torso potential) from multiple different locations around the patient's torso. Each of the different locations where the electrodes are located can correspond to the electrical activation of different cardiac tissue portions or regions of the patient's heart. Thus, for example, after a signal has propagated through the patient's torso, multiple electrodes can record or monitor electrical signals associated with depolarization and repolarization at multiple different locations in or near the heart. According to various embodiments, the multiple external electrodes can comprise or include multiple anterior electrodes positioned on the skin near the front of the patient's torso, lateral or left-sided electrodes positioned on the skin near the left or right side of the patient's torso, and posterior electrodes positioned on the skin near the rear of the patient's torso.

[0065] It can be described that, when using multiple external electrodes, the monitoring process 410 can provide multiple electrocardiograms (ECGs) representing the depolarization and repolarization of the patient's heart. The multiple ECGs can then be used to generate alternative cardiac electrical activation times 415 representing cardiac depolarization. As described herein, the alternative cardiac electrical activation time can, for example, represent the actual or local electrical activation time of one or more regions of the patient's heart. Measurement of activation time can be performed by selecting an appropriate reference point (e.g., peak, minimum, minimum slope, maximum slope, zero crossover point, threshold crossover point, etc. of the near-field or far-field EGM) and measuring the time between the start of cardiac depolarization (e.g., the start of a QRS complex) and the appropriate reference point (e.g., within electrical activity). The activation time between the start of the QRS complex (or peak Q wave) and the reference point can be referred to as the q-LV time. In at least one embodiment, the earliest QRS start from all the multiple electrodes can be used as the starting point for each activation time of each electrode, and the maximum slope after the start of the QRS complex can be used as the ending point for each activation time of each electrode.

[0066] The monitored electrical activity 410 and electrical activation time 415 can be used to generate electrical heterogeneity information (EHI) 420. The 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, the EHI can represent a substitute for the actual mechanical and / or electrical function of the patient's heart. In at least one embodiment, the relative change 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 a substitute value representing a change in hemodynamic response (e.g., a sharp change in the LV pressure gradient). Left ventricular pressure can typically be invasively monitored using a pressure sensor located in the left ventricle of the patient's heart. Thus, using EHI to determine a substitute value representing left ventricular pressure avoids the need for invasive monitoring using a left ventricular pressure sensor.

[0067] In at least one embodiment, EHI may include the use of, for example, methods described herein. Figure 1-3 The standard deviation of ventricular activation time measured by some or all of the external electrodes of the described electrode device 110. Further, the local or regional EHI may include the standard deviation and / or mean of activation times measured using electrodes located in certain anatomical regions of the trunk. For example, external electrodes on the left side of the patient's trunk may be used to calculate the local or regional left EHI.

[0068] EHI can be generated using one or more different systems and / or methods. For example, EHI can be generated using surface electrodes and / or imaging system arrays or multiple surface electrodes and / or imaging systems, as described in the following documents: U.S. Patent No. 9,510,763B2, issued December 6, 2016, entitled "Assessing Intra-Cardiac Activation Patterns and Electrical Dyssynergy"; U.S. Patent No. 8,972,228B2, issued March 3, 2015, entitled "Assessing Intra-Cardiac Activation Patterns"; and U.S. Patent No. 8,180,428B2, issued May 15, 2012, entitled "Methods and Systems for Using Inselecting Cardiac Pacing Sites".

[0069] EHI can include one or more measures or indicators. For example, one measure or indicator of electrical heterogeneity could be the standard deviation of activation time (SDAT) measured using some or all electrodes on the surface of a patient's torso. In some instances, SDAT can be calculated using alternative or estimated cardiac activation times on the surface of a model heart.

[0070] In this example, EHI includes one or more left-side metrics or left-side measures generated based on the left-side activation time, which is an alternative cardiac electrical activation time measured using multiple left external electrodes. The left external electrodes may comprise multiple left external electrodes positioned on the left side of the patient's torso.

[0071] One measure or index of electrical heterogeneity or asynchrony can be the left standard deviation of the surrogate cardiac electrical activation time (LVED) monitored by an external electrode located near the patient's left side. Further, another measure or index of electrical heterogeneity can comprise the mean of the surrogate cardiac electrical activation time (LVAT) monitored by an external electrode located near the patient's left side. LVED and LVAT can be determined (e.g., calculated, estimated, etc.) based solely on electrical activity measured by electrodes near the patient's left side, which may be referred to as "left" electrodes. The activation time determined or measured from the left electrode can be described as the left-side activation time. A left electrode can be defined as any surface electrode located near the left ventricle encompassing the left side of the patient's sternum and spine (e.g., towards the patient's left arm, the patient's left side, etc.). In one embodiment, the left electrode may comprise all anterior electrodes on the left side of the sternum and all posterior electrodes on the left side of the spine. In another embodiment, the left electrode may comprise all anterior electrodes and all posterior electrodes on the left side of the sternum. In yet another embodiment, the left electrode can be designated based on the contours of the left and right sides of the heart, as determined using imaging equipment (e.g., X-rays, fluorescence fluoroscopy, etc.).

[0072] Another illustrative left metric or indicator of electrical heterogeneity or synchronicity may include the percentage of left-sided late activation in the left-sided alternative cardiac electrical activation time. In one or more embodiments, the percentage of left-sided late activation in the left-sided alternative cardiac electrical activation time may be determined using a left-sided late activation threshold. For example, the percentage of left electrodes that produce an alternative cardiac electrical activation time greater than or equal to the left-sided late activation threshold may be the left-sided late activation percentage. In at least one embodiment, the left-sided late activation threshold is 50 milliseconds (ms). The left-sided late activation threshold may be between about 35 ms and about 85 ms. In one or more embodiments, the left-sided late activation threshold is greater than or equal to 35 ms, greater than or equal to 45 ms, greater than or equal to 55 ms, greater than or equal to 65 ms, etc., and / or less than or equal to 85 ms, less than or equal to 75 ms, less than or equal to 60 ms, less than or equal to 50 ms, etc.

[0073] Therefore, in the example with a left-sided late activation threshold of 40 ms, if 22 out of 32 left electrodes have an alternative cardiac electrical activation time of 40 ms or more, the percentage of left-sided late activation is 69%. Furthermore, in the example with a left-sided late activation threshold of 45 ms, if 4 out of 32 left electrodes have an alternative cardiac electrical activation time of 45 ms or more, the percentage of left-sided late activation is 13%. A high percentage of left-sided late activation likely indicates a significant delay in activation in the left region of the patient's heart (e.g., the left ventricle).

[0074] Then, the illustrative method 400 can determine, based on the generated EHI, and specifically the left or left-sided EHI, whether cardiac conduction system pacing therapy will be beneficial to the patient 430. For example, one or both of the left-sided late activation percentage and LVAT can be analyzed to determine whether cardiac conduction system pacing therapy is beneficial to the patient 430. Furthermore, it should be understood that determining whether cardiac conduction system pacing therapy is beneficial to the patient 430 may not necessarily be a binary yes-or-no determination, but rather may be the probability of success of cardiac conduction system pacing therapy for the patient. For example, the probability of success of cardiac conduction system pacing therapy can be expressed or represented by a percentage or by descriptors such as “cardiac conduction system pacing therapy is likely to be beneficial,” “cardiac conduction system pacing therapy is likely to be beneficial,” “cardiac conduction system pacing therapy is unlikely to be beneficial,” and “cardiac conduction system pacing therapy is extremely unlikely to be beneficial.”

[0075] Additionally, for example, an indication of whether cardiac conduction system pacing therapy will benefit the patient based on the generated EHI (such as the left EHI) can be displayed on a graphical user interface. More specifically, for example, after an electrode device containing multiple external electrodes has been applied to the patient, the user (e.g., a clinician, physician, etc.) can initiate cardiac conduction system benefit determination using the graphical user interface of the display by, for example, selecting a button or other area on the graphical user interface. Thus, in response to the user initiating cardiac conduction system pacing therapy benefit determination, the illustrative system and method can monitor electrical activity 410, measure the alternative cardiac electrical activation time 415, generate an EHI 420, determine whether cardiac conduction system pacing therapy will benefit the patient 430 based on the generated EHI, and then display an indication of whether cardiac conduction system pacing therapy will benefit the patient on a graphical user interface.

[0076] Figure 5B The illustration shows a method 430 for determining whether cardiac conduction system pacing therapy will benefit the patient of method 400. Method 430 may utilize one or both of left late activation percentage and LVAT to determine whether cardiac conduction system pacing therapy will benefit the patient 430.

[0077] The percentage of left-sided late activation can be compared to the 40% threshold for left-sided late activation shown in this example 432. Therefore, if the percentage of left-sided late activation is greater than or equal to 40%, a cardiac conduction block is determined to be located in a proximal region closer to the cardiac conduction network 436, and further, cardiac conduction pacing therapy is determined to be beneficial 438. Conversely, if the percentage of left-sided late activation is less than 40%, a cardiac conduction block is determined to be located in a distal region closer to the cardiac conduction network 440, and further, cardiac conduction pacing therapy is unlikely to be beneficial 442.

[0078] The left-sided late activation percentage threshold can be between approximately 30% and approximately 80%. In one or more embodiments, the left-sided late activation percentage threshold is greater than or equal to 30%, greater than or equal to 40%, greater than or equal to 60%, greater than or equal to 70%, etc., and / or less than or equal to 80%, less than or equal to 65%, less than or equal to 50%, etc.

[0079] The LVAT can be compared to the 50 ms LVAT threshold 434 shown in this example. Therefore, if the LVAT is greater than or equal to 50 ms, it is determined that the cardiac conduction block is set or located closer to the proximal region of the cardiac conduction network 436, and further determined that cardiac conduction pacing therapy is beneficial 438. Conversely, if the LVAT is less than 50 ms, it is determined that the cardiac conduction block is set or located closer to the distal region of the cardiac conduction network 440, and further determined that cardiac conduction pacing therapy is unlikely to be beneficial 442.

[0080] The LVAT threshold can be between approximately 35 ms and approximately 85 ms. In one or more embodiments, the left-side late activation threshold is greater than or equal to 35 ms, greater than or equal to 45 ms, greater than or equal to 55 ms, greater than or equal to 65 ms, etc., and / or less than or equal to 85 ms, less than or equal to 75 ms, less than or equal to 60 ms, less than or equal to 50 ms, etc.

[0081] Optionally, each of the left late activation percentage and LVAT determination processes 432, 434 can be used in combination to determine whether cardiac conduction system pacing therapy would be beneficial to the patient 430. For example, in this embodiment, the left late activation percentage must be greater than or equal to a left late activation percentage threshold 432 and the LVAT must be greater than or equal to an LVAT threshold 434 to determine a proximal region setting or location of cardiac conduction system block closer to the cardiac conduction network 436, and further determine that cardiac conduction system pacing therapy is beneficial 438. Conversely, in this embodiment, if only one of the left late activation percentage and LVAT is greater than or equal to its corresponding threshold, a distal region setting or location of cardiac conduction system block closer to the cardiac conduction network is determined 440, and further determine that cardiac conduction system pacing therapy is unlikely to be beneficial 442.

[0082] Figure 6AThe paper depicts three distinct sets of intrinsic ECG data from patients who subsequently underwent His bundle pacing. More specifically, the intrinsic or baseline LVAT mean and range for 15 patients, the intrinsic or baseline SDAT mean and range for the same 15 patients, and the intrinsic or baseline QRS duration mean and range for the same 15 patients are shown. As illustrated, using cardiac conduction system pacing therapy—specifically His bundle pacing—left bundle branch block was successfully treated in 6 of the 15 patients. It can be seen that a 55 ms LVAT threshold would correctly identify 6 of the 6 patients successfully treated with His bundle pacing (i.e., 100% sensitivity) and 8 of the 9 patients unsuccessfully treated with His bundle pacing (i.e., 89% specificity). As illustrated, the p-value for LVAT is 0.04. In contrast, there were no significant differences in global measures, SDAT, or QRS duration between patients who were successfully corrected with His bundle pacing and those who were not, with p-values ​​of 0.15 and 0.69, respectively.

[0083] Figure 6B The image depicts intrinsic or baseline activation and anterior and posterior activation during His bundle pacing in two patients (Subject A and Subject B) undergoing left bundle branch block. As shown, Subject A and Subject B had similar SDAT during intrinsic activation—41.2 ms and 37.3 ms, respectively—but significantly different LVAT during intrinsic activation—63.3 ms and 46.6 ms, respectively.

[0084] The illustrative system and method can determine that subject A will benefit from conduction system pacing therapy because, for example, subject A's inherent LVAT exceeds the 50 ms LVAT threshold. Conversely, the illustrative system and method may not determine that subject B will benefit from conduction system pacing therapy because, for example, subject B's inherent LVAT is less than the 50 ms LVAT threshold.

[0085] Results from the administration of His bundle pacing to both subjects A and B indicate that the illustrative system and methodology are correct, as His bundle pacing appears to benefit only subject A. More specifically, during His bundle pacing, subject A's SDAT decreased by nearly 50% and LVAT decreased by 37%. In contrast, subject B's SDAT decreased slightly by about 15%, while LVAT actually increased by 18%. In one or more embodiments, the threshold used to determine whether left bundle branch block has been corrected is a reduction in LVAT from intrinsic or baseline levels of greater than 20%.

[0086] As described herein, illustrative systems and methods can help users (e.g., clinicians, physicians, etc.) determine whether a patient can benefit from cardiac conduction system pacing therapy and / or determine the location of cardiac conduction system blockage within or along the cardiac conduction network. In one or more embodiments, illustrative cardiac conduction system pacing therapy can utilize any implantable or non-implantable cardiac pacing system designed to pace or deliver electrical pacing to one or more zones or regions of a patient's cardiac conduction system. Cardiac conduction system pacing therapy can use a single pacing electrode defining a single pacing vector or multiple pacing electrodes defining multiple pacing vectors.

[0087] An example of cardiac conduction system pacing therapy can be found in this article. Figure 7-10 Atrial-to-ventricular (VfA) pacing therapy 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.

[0088] Another example of cardiac conduction system pacing therapy can be 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 BundleBranch Pacing Adjustment," which is incorporated herein by reference in its entirety. Yet another example of cardiac conduction system pacing therapy can be 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."

[0089] Figure 7 The text describes an illustrative atrioventricular (VfA) cardiac therapy system, which can be configured to, for example, be described herein with respect to... 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 led 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.

[0090] 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 patient's 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.

[0091] 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.

[0092] 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).

[0093] The cardiac therapy system 2 may also include a separate medical device 50 (in Figure 7(Illustrated schematically) The individual medical device 50 can be positioned outside (e.g., subcutaneously) the patient's heart 8 and can be operatively coupled to the patient's heart 8 to deliver cardiac therapy thereto. In one example, the individual medical device 50 can be an extravascular ICD. In some embodiments, the extravascular ICD can include a defibrillation lead that includes or carries a defibrillation electrode. A therapy carrier can 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 can also be used to sense electrical signals related to the patient's heart 8. The ICD can be configured to deliver electrical shock therapy comprising one or more defibrillation or cardioversion shocks. For example, if an arrhythmia is sensed, the ICD can send pulses through the lead to shock the heart and restore its normal rhythm. In some instances, the ICD can 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, which is incorporated herein by reference in its entirety.

[0094] 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.

[0095] 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.

[0096] 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 operational 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.

[0097] Figure 8 yes Figure 7 An enlarged conceptual diagram of the intracardiac medical device 10 and the anatomical structure 8 of a patient's heart. Specifically, the device 10 is configured to sense cardiac signals and / or deliver pacing therapy. The intracardiac device 10 may include a housing 30. The housing 30 may define the internal components of the 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 instances, the housing 30 may contain (e.g., formed therefrom or derived therefrom) non-conductive materials, including ceramics, glass, sapphire, silicone, polyurethane, epoxy resins, acetyl copolymer plastics, polyetheretherketone (PEEK), liquid crystal polymers, or other biocompatible polymers.

[0098] 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.

[0099] All or part of the housing 30 may serve as a sensing and / or pacing electrode during cardiac therapy. In the example shown, 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 or formed of a conductive material such as titanium alloy or other examples listed above) is partially electrically insulated from a non-conductive material (e.g., a coating of parylene, polyurethane, silicone, epoxy resin, or other biocompatible polymers), one or more discrete regions of the conductive material are exposed to form or define a 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 material) is present, 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 a 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, through a conductive housing 30 or, when the housing 30 is a non-conductive material.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.).

[0106] 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.

[0107] 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 about 3 mm to about 8 mm. The diameter of the shaft 40 may be less than about 2 mm and may be about 1 mm or less, or even about 0.6 mm or less.

[0108] Figure 9 This is a two-dimensional (2D) ventricular diagram 300 of the patient's heart (e.g., a top-down view), showing the left ventricle 320 and right ventricle 322 in a standard 17-segment view. The two-dimensional (2D) ventricular diagram 300 of the patient's heart defines or includes multiple zones 326 corresponding to different regions of the human heart. As shown, zones 326 are numbered 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). Zones 326 of the two-dimensional (2D) ventricular diagram 300 of the patient's heart may include the anterior basal zone 1, anterior basal septal zone 2, subbasal septal zone 3, subbasal zone 4, subbasal lateral zone 5, anterior basal lateral zone 6, anterior mid-septal zone 7, anterior mid-septal zone 8, inferior mid-septal zone 9, inferior mid-septal zone 10, inferior mid-lateral zone 11, anterior mid-lateral zone 12, anterior vertex zone 13, vertex septal zone 14, inferior vertex zone 15, lateral vertex zone 16, and vertex zone 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.

[0109] In some embodiments, any tissue-piercing electrode of this disclosure may be implanted in the basal and / or septal 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 at the target implantation area 4 ( Figure 7-8In the ventricular region, such as the basal and / or septal regions of the left ventricular myocardium. Referring to a two-dimensional (2D) ventricular diagram 300 of the patient's heart, the basal region includes one or more of the following: prebasal region 1, prebasal septal region 2, subbasal septal region 3, subbasal region 4, mid-anterior region 7, mid-anterior septal region 8, mid-inferior septal region 9, and mid-inferior region 10. Referring to a two-dimensional (2D) ventricular diagram 300 of the patient's heart, the septal region includes one or more of the following: prebasal septal region 2, prebasal septal region 3, mid-anterior septal region 8, mid-inferior septal region 9, and apical septal region 14.

[0110] In some embodiments, when implanted, the tissue-puncturing electrode may be positioned in the basal-septal region of the left ventricular myocardium. The basal septal region may include one or more of the following: anterior basal septal region 2, subbasal septal region 3, anterior mid-septal region 8, and inferior mid-septal region 9.

[0111] In some embodiments, when implanted, the tissue-puncturing electrode can be positioned in the superior / posterior basal septal region of the left ventricular myocardium. The superior / posterior basal septal region of the left ventricular myocardium may include a portion of one or more of the subbasal septal region 3 and the mid-inferior septal region 9 (e.g., only the subbasal septal region, only the mid-inferior septal region, or both the subbasal septal region and the mid-inferior septal region). For example, the superior / posterior basal septal 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 septal region, and its shape or size may vary slightly depending on the specific application.

[0112] Figure 10 The diagram depicts a block diagram of a circuit system, according to one example, that can be enclosed within a housing 30 of device 10 or the housing of any other medical device described herein to provide the function of sensing cardiac signals, determining capture and / or delivering pacing therapy. Figure 7The individual medical device 50 shown may contain 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 if cardiac 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, sensor 90 may include a patient activity sensor 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.

[0113] 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 discharges 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.

[0114] Figure 10The functional blocks shown represent 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), combinational logic circuitry, state machines, or other suitable components or combinations thereof that provide the described functions, executing one or more software or firmware programs. 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 used by the medical device.

[0115] 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.

[0116] 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.

[0117] Sensing circuit 86 may include an atrial (A) sensing channel 87 and a ventricular (V) sensing channel 89. Distal housing-based electrode 22 and proximal housing-based electrode 24 may be coupled to 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 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. Tip electrode 42 and proximal housing-based electrode 24 may be coupled to ventricular sensing channel 89 to sense ventricular signals, such as R waves associated with ventricular myocardial depolarization.

[0118] 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.

[0119] 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.

[0120] In some instances, device 10 can 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 can be configured to detect non-sinus tachycardia and deliver ATP. Control circuitry 80 can 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 can be compared with tachycardia detection intervals to detect non-sinus tachycardia. Tachycardia can be detected in a given cardiac chamber based on a threshold number of detected tachycardia detection intervals.

[0121] 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 holding capacitor is 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 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.

[0122] 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 responsiveness 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).

[0123] 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.

[0124] 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.

[0125] The technologies described in this disclosure, including those belonging 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 technologies 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” generally refer to any circuit system, alone or in combination with other logic circuit systems, or any other equivalent circuit system.

[0126] 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.

[0127] 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 circuitry system and / or one or more processors to support one or more aspects of the functionality described in this disclosure.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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).

[0132] 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).

[0133] Orientation-related terms, such as “top,” “bottom,” “side,” and “end,” are used to describe the relative positioning 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 can rotate in various directions, unless otherwise clearly indicated by the content.

[0134] 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.

[0135] 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.”

[0136] As used in this article, terms such as “have,” “having,” “include,” “including,” “comprise,” and “comprising” are used in their open-ended sense and generally mean “including but not limited to.” It should be understood that phrases such as “basically composed of” or “composed of” are included within the term “including.”

[0137] 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.

[0138] Illustrative Examples

[0139] Example 1: A system comprising:

[0140] An electrode device comprising a plurality of external electrodes disposed close to the patient's skin, wherein the plurality of external electrodes includes a plurality of left external electrodes positioned on the left side of the patient's torso; and

[0141] A computing device, comprising a processing circuitry system coupled to the electrode device and configured to:

[0142] The alternative cardiac electrical activation time is measured using the plurality of external electrodes of the electrode device during the patient's intrinsic cardiac activation, wherein the alternative cardiac electrical activation time represents cardiac tissue depolarization propagating through the patient's trunk.

[0143] Electrical heterogeneity information (EHI) is generated based on the measured alternative cardiac electrical activation time, wherein the EHI includes one or more left metrics generated based on the left activation time of the alternative cardiac electrical activation time measured using the plurality of left external electrodes, and

[0144] Whether cardiac conduction system pacing therapy would benefit the patient is determined at least based on one or more of the left limb measurements.

[0145] Example 2: A method comprising:

[0146] The surrogate cardiac electrical activation time is measured using multiple external electrodes placed close to the patient's skin during the patient's intrinsic cardiac activation, wherein the multiple external electrodes include multiple left external electrodes positioned on the left side of the patient's torso, and wherein the surrogate cardiac electrical activation time represents cardiac tissue depolarization propagating through the patient's torso.

[0147] Electrical heterogeneity information (EHI) is generated based on the measured alternative cardiac electrical activation time, wherein the EHI includes one or more left metrics generated based on the left activation time of the alternative cardiac electrical activation time measured using the plurality of left external electrodes, and

[0148] Whether the cardiac conduction system pacing therapy will benefit the patient is determined at least based on one or more of the left metric measurements.

[0149] Example 3: A system or method according to any one of Examples 1 and 2, wherein the patient’s cardiac conduction system extends from a proximal region near the patient’s sinoatrial node or atrioventricular node to a distal region near the Purkinje fibers of the patient’s defined cardiac conduction network, wherein determining whether cardiac conduction system pacing therapy would benefit the patient based at least on the one or more left measurements includes determining whether cardiac conduction system block is located along the cardiac conduction network closer to the proximal region than the distal region.

[0150] Example 4: The system or method according to any one of Examples 1 to 3, wherein the one or more left metrics include a left late activation percentage of the left activation time that is greater than or equal to the left late activation threshold.

[0151] Example 5: The system or method according to Example 4, wherein the left-side late activation threshold is greater than or equal to 40 milliseconds.

[0152] Example 6: The system or method according to any one of Examples 4 and 5, wherein determining whether the cardiac conduction system pacing therapy will benefit the patient based at least on the one or more left-side metrics includes: determining that the cardiac conduction system pacing therapy will benefit the patient if the percentage of left-side late activation during the left-side activation time is greater than or equal to 40%.

[0153] Example 7: The system or method according to any one of Examples 1 to 6, wherein the one or more left metrics include the left average of the left activation times.

[0154] Example 8: According to the system or method of Example 7, determining whether the cardiac conduction system pacing therapy will benefit the patient based at least on the one or more left-side metrics includes: determining that the cardiac conduction system pacing therapy will benefit the patient if the left-side average of the left-side activation time is greater than or equal to 50 milliseconds.

[0155] Example 9: A system or method according to any one of Examples 1 to 8, wherein the cardiac conduction system pacing therapy includes one or more atrial-to-ventricular (VfA) pacing therapies, His bundle pacing therapies, left bundle branch pacing, and septal left ventricular endocardial pacing.

[0156] Example 10: A system comprising:

[0157] An electrode device comprising a plurality of external electrodes disposed close to the patient's skin, wherein the plurality of external electrodes includes a plurality of left external electrodes positioned on the left side of the patient's torso; and

[0158] A computing device, comprising a processing circuitry system coupled to the electrode device and configured to:

[0159] The alternative cardiac electrical activation time is measured using the plurality of external electrodes of the electrode device during the patient's intrinsic cardiac activation, wherein the alternative cardiac electrical activation time represents cardiac tissue depolarization propagating through the patient's trunk.

[0160] Electrical heterogeneity information (EHI) is generated based on the measured alternative cardiac electrical activation time, wherein the EHI includes one or more left metrics generated based on the left activation time of the alternative cardiac electrical activation time measured using the plurality of left external electrodes, and

[0161] The determination of whether a cardiac conduction block is located closer to a proximal region than a distal region is based at least on one or more left measurements.

[0162] Example 11: According to the system of Example 10, wherein the one or more left metrics include a left late activation percentage of left activation time that is greater than or equal to a left late activation threshold.

[0163] Example 12: The system according to Example 11, wherein the left-side late activation threshold is greater than or equal to 40 milliseconds.

[0164] Example 13: The system according to any one of Examples 11 and 12, wherein determining whether a cardiac conduction block is located closer to the proximal region than the distal region along the patient's cardiac conduction network based at least on the one or more left measurements comprises: determining that the cardiac conduction block is closer to the proximal region than the distal region if the percentage of left late activation of the left activation time is greater than or equal to 40%.

[0165] Example 14: The system according to any one of Examples 10 to 13, wherein the one or more left metrics include the left average of the left activation time.

[0166] Example 15: According to the system of Example 14, determining whether a cardiac conduction block is located closer to the proximal region than the distal region along the patient's cardiac conduction network based at least on the one or more left metrics includes: determining that the cardiac conduction block is closer to the proximal region than the distal region if the left average of the left activation time is greater than or equal to 50 milliseconds.

[0167] Example 16: The system according to Examples 10 to 16, wherein the cardiac conduction system pacing therapy includes one or more atrial-to-ventricular (VfA) pacing therapies, His bundle pacing therapies, left bundle branch pacing, and septal left ventricular endocardial pacing.

[0168] Example 17: A system comprising:

[0169] An electrode device comprising a plurality of external electrodes disposed close to the skin of a patient, wherein the plurality of external electrodes includes a plurality of left external electrodes positioned on the left side of the patient’s torso;

[0170] The display includes a graphical user interface to present information to help the user assess whether the patient will benefit from cardiac conduction system pacing therapy; and

[0171] A computing device, comprising a processing circuitry system coupled to the electrode device and the display, and configured to:

[0172] Allowing the user to initiate cardiac conduction system pacing therapy benefit determination on the graphical user interface,

[0173] In response to the user initiating the cardiac conduction system pacing therapy, the alternative cardiac electrical activation time is measured using the plurality of external electrodes of the electrode device during the patient's intrinsic cardiac activation, wherein the alternative cardiac electrical activation time represents the cardiac tissue depolarization propagating through the patient's trunk.

[0174] Electrical heterogeneity information (EHI) is generated based on the measured alternative cardiac electrical activation time, wherein the EHI includes one or more left metrics generated based on the left activation time of the alternative cardiac electrical activation time measured using the plurality of left external electrodes, and

[0175] The graphical user interface displays an indication of whether pacing therapy of the cardiac conduction system, based at least on one or more left-hand measurements, would be beneficial to the patient.

[0176] Example 18: The system according to Example 17, wherein the patient’s cardiac conduction system extends from a proximal region near the patient’s sinoatrial node or atrioventricular node to a distal region near the Purkinje fibers of the patient’s defined cardiac conduction network, wherein an indication of whether pacing therapy of the cardiac conduction system would benefit the patient, based at least on the one or more left measures, includes an indication of the location of the cardiac conduction system block along the cardiac conduction network.

[0177] Example 19: The system according to any one of Examples 17 to 18, wherein the computing device is further configured to display the one or more left metrics on the graphical user interface.

[0178] Example 20: The system according to any one of Examples 17 to 18, wherein the one or more left metrics include a left late activation percentage of left activation time that is greater than or equal to a left late activation threshold.

Claims

1. A system for determining the therapeutic benefit of a cardiac conduction system, the system comprising: An electrode device comprising a plurality of external electrodes disposed close to the skin of a patient, wherein the plurality of external electrodes includes a plurality of left external electrodes positioned on the left side of the patient’s torso; as well as A computing device, comprising a processing circuitry system coupled to the electrode device and configured to: The alternative cardiac electrical activation time is measured using the plurality of external electrodes of the electrode device during the patient's intrinsic cardiac activation, wherein the alternative cardiac electrical activation time represents cardiac tissue depolarization propagating through the patient's trunk. Electrical heterogeneity information is generated based on the measured alternative cardiac electrical activation time, wherein the electrical heterogeneity information includes one or more left metrics generated based on the left activation time of the alternative cardiac electrical activation time measured using the plurality of left external electrodes, and Whether cardiac conduction system pacing therapy would benefit the patient is determined at least based on one or more of the left limb measurements.

2. The system of claim 1, wherein the patient’s cardiac conduction system extends from a proximal region near the patient’s sinoatrial node or atrioventricular node to a distal region near the Purkinje fibers of the patient’s defined cardiac conduction network, wherein determining whether cardiac conduction system pacing therapy would benefit the patient based at least on the one or more left measurements includes determining whether cardiac conduction system block is positioned along the cardiac conduction network closer to the proximal region than the distal region.

3. The system according to any one of claims 1 to 2, wherein the one or more left metrics include a left-side late activation percentage of the left-side activation time that is greater than or equal to a left-side late activation threshold.

4. The system of claim 3, wherein the left-side late activation threshold is greater than or equal to 40 milliseconds.

5. The system of claim 3, wherein determining whether the cardiac conduction system pacing therapy will benefit the patient based at least on the one or more left metrics comprises: If the percentage of left-sided late activation during the left-sided activation time is greater than or equal to 40%, then the cardiac conduction system pacing therapy is determined to be beneficial to the patient.

6. The system according to any one of claims 1 to 2, wherein the one or more left metrics include the left average of the left activation times.

7. The system of claim 6, wherein determining whether the cardiac conduction system pacing therapy will benefit the patient is based at least on the one or more left metric measurements includes: If the left average of the left activation time is greater than or equal to 50 milliseconds, then the cardiac conduction system pacing therapy is determined to be beneficial to the patient.

8. The system according to any one of claims 1 to 2, wherein the cardiac conduction system pacing therapy comprises one or more atrial-to-ventricular (VfA) pacing therapies, His bundle pacing therapies, left bundle branch pacing, and septal left ventricular endocardial pacing.

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