Atrial lead placement for the treatment of atrial dyssynchrony

Abstract

A system and method for positioning an atrial pacing lead for delivery of cardiac pacing therapy includes sensing electrical activity in a patient's tissues from a plurality of external electrodes and determining a distribution of bi-atrial activation in response to the sensed electrical activity. A target site for delivery of atrial pacing therapy is adjusted based on changes in bi-atrial asynchrony determined in response to the determined distribution of bi-atrial activation, and the placement of the atrial pacing lead for delivery of atrial pacing therapy is determined in response to this adjustment.

Description

[0001] The disclosure herein relates to implantable medical systems and methods for evaluating the placement of atrial leads for the treatment of atrial dyssynchrony in atrial pacing therapy. Background Technology

[0002] During normal sinus rhythm (NSR), the heartbeat is regulated by electrical signals generated by the sinoatrial (SA) node located in the wall of the right atrium. Each atrial depolarization signal generated by the SA node diffuses across the atrium (causing atrial depolarization and contraction) and reaches the atrioventricular (AV) node. The AV node responds by propagating the ventricular depolarization signal through the His bundle in the ventricular septum and subsequently to the bundle branches of the right and left ventricles and the Purkinje muscle fibers.

[0003] Atrial tachyarrhythmias include the nonorganic form of atrial fibrillation and organized atrial tachycardia of various degrees, including atrial flutter. Atrial fibrillation (AF) occurs due to multiple focal triggers in the atria or due to heterogeneous changes in the atrial matrix that cause conduction through different regions of the atria. Ectopic triggers may originate anywhere in the left or right atrium or pulmonary veins. The AV node will be bombarded with frequent and irregular atrial impulses, but will only conduct depolarizing signals when the AV node is not in its refractory period. The ventricular cycle length will be irregular and will depend on the different states of AV node refractoryness.

[0004] Patients with atrial dyssynchrony exhibit wide P waves and slower atrial conduction, which can lead to delayed atrial kick and reduced contribution of atrial kick to filling, impairing ventricular function (heart failure). Atrial dyssynchrony can also be a cause of atrial arrhythmias and atrial fibrillation. Other approaches, such as atrial pacing therapy targeting the Bachmann's bundle for synchronized atrial excitation or multi-site atrial stimulation, can help restore atrial synchrony and lead to better outcomes in these patients, including improved heart failure symptoms and a potential reduction in the burden of atrial arrhythmias. Therefore, there is growing interest in methods and devices for improving the determination of one or more desired locations for pacing therapy that delivers pacing therapy within the atrium, resulting in an overall improvement in biatrial synchrony. Summary of the Invention

[0005] The exemplary systems, methods, and interfaces described herein can be configured to assist users (e.g., physicians) in assessing patients and / or evaluating the placement of pacing leads for delivering pacing therapy during and / or after implantation of a cardiac treatment device. In one or more embodiments, portions of the systems, methods, and interfaces can be described as non-invasive. For example, in some embodiments, the systems and methods can use non-invasive electrical measurements obtained using, for example, multiple external electrodes attached to the patient's skin around the patient's torso.

[0006] In at least one example, a method for positioning an atrial pacing lead for delivery of cardiac pacing therapy includes: sensing electrical activity in patient tissue from a plurality of external electrodes; determining a distribution of bi-atrial activation in response to the sensed electrical activity; determining a change in bi-atrial asynchrony in response to the determined distribution of bi-atrial activation; adjusting a target site for delivery of atrial pacing therapy in response to the determined change in bi-atrial asynchrony; and determining placement of the atrial pacing lead for delivery of atrial pacing therapy in response to the adjustment.

[0007] In another example, a method of placing an atrial pacing lead for delivery of cardiac pacing therapy includes performing at least one of the following: positioning a single lead at a location adjacent to the Bachmann bundle; positioning a single lead in the right atrium; positioning a single lead in the left atrium; positioning a single lead at the atrial septum; and positioning a single lead in both the right and left atrium; delivering atrial pacing therapy in response to the performed positioning; sensing electrical activity of patient tissue from a plurality of external electrodes in response to the delivered atrial pacing therapy; determining the distribution of bi-atrial activation in response to the sensed electrical activity; determining whether there is a desired change in bi-atrial asynchrony in response to the determined distribution of bi-atrial activation; determining whether the lead placement endpoint has been reached; and determining the target site for delivery of atrial pacing therapy in response to reaching the lead placement endpoint.

[0008] In another example, a system for determining the location of an atrial pacing lead for delivery of cardiac pacing therapy includes: a plurality of external electrodes for sensing electrical activity in patient tissue; and a computing device configured to: determine a distribution of bi-atrial activation in response to the sensed electrical activity; determine a change in bi-atrial asynchrony in response to the determined distribution of bi-atrial activation; adjust a target site for delivery of atrial pacing therapy in response to the determined change in bi-atrial asynchrony; and determine the placement of the atrial pacing lead for delivery of atrial pacing therapy in response to the adjustment.

[0009] In another example, a system for determining the location of an atrial pacing lead for delivery of cardiac pacing therapy includes: one or more pacing electrodes for delivering atrial pacing therapy in response to performing at least one of the following: positioning a single lead at a location adjacent to the Bachmann bundle, positioning a single lead in the right atrium, positioning a single lead in the left atrium, positioning a single lead at the atrial septum, and positioning a single lead in both the right and left atrium; a plurality of external electrodes for sensing electrical activity in patient tissue in response to the delivered atrial pacing therapy; and a computing device configured to: determine a distribution of bi-atrial activation in response to the sensed electrical activity, determine the presence of a desired change in bi-atrial asynchrony in response to the determined distribution of bi-atrial activation, determine whether the lead placement endpoint has been reached, and determine a target site for delivery of atrial pacing therapy in response to reaching the lead placement endpoint.

[0010] The above description is not intended to depict every embodiment or implementation of this disclosure. A more complete understanding will become apparent and understandable by referring to the following detailed description, taken in conjunction with the accompanying drawings and the claims. Attached Figure Description

[0011] Figure 1 This is a diagram of an exemplary system including an electrode device, a display device, and a computing device.

[0012] Figure 2-3 This is a diagram of an exemplary external electrode device for measuring the surface potential of the torso.

[0013] Figure 4 This is a schematic diagram of an exemplary medical device for detecting arrhythmias according to embodiments of the present disclosure.

[0014] Figure 5 yes Figure 4 A functional diagram of the medical equipment.

[0015] Figure 6 This is a flowchart illustrating a method for determining a measure of biventricular asynchrony in atrial lead placement, based on examples of this disclosure.

[0016] Figure 7 This is a schematic diagram illustrating the determination of P-wave excitation according to an example of this disclosure.

[0017] Figure 8 This is an exemplary illustration generated based on the distribution of atrial excitation information according to an example of this disclosure.

[0018] Figure 9 This is a flowchart illustrating a method for determining the placement of an atrial lead for delivering atrial pacing therapy, according to an example of this disclosure. Detailed Implementation

[0019] In the following detailed description of illustrative embodiments, reference is made to the accompanying drawings, which form part of the embodiments and illustrate specific embodiments that can be practiced by way of illustration. It should be understood that other embodiments may be adopted and structural changes may be made without departing from (e.g., still falling within) the scope of the disclosure presented herein.

[0020] Reference Figures 1-9 Exemplary systems and methods are described herein. It will be apparent to those skilled in the art that elements or processes from one embodiment may be used in combination with elements or processes from other embodiments, and possible embodiments of such methods and systems using combinations of features set forth herein are not limited to the specific embodiments shown in the drawings and / or described herein. Furthermore, it will be appreciated that the embodiments described herein may include a number of elements that are not necessarily shown to scale. Even further, it will be appreciated that the timing of the processes and the dimensions and shapes of the various elements herein may be modified but still fall within the scope of this disclosure; however, certain timings, one or more shapes and / or dimensions, or types of elements may be advantageous relative to other timings, shapes and / or dimensions, or types of elements.

[0021] The various exemplary systems, methods, and interfaces described herein can be configured to non-invasively assist a user (e.g., a physician) in assessing a patient's condition and / or performing or delivering atrial dyssynchrony pacing cardiac therapy to a patient using electrode devices, display devices, and computing devices including external electrodes. Patients with atrial dyssynchrony have wide P waves and slower atrial conduction, which can lead to delayed atrial expulsion and reduced contribution of atrial expulsion to filling, which can impair ventricular function (heart failure). Atrial dyssynchrony can also be a cause of atrial arrhythmias and atrial fibrillation.

[0022] Other approaches, such as atrial pacing therapy targeting the Bachmann bundle for synchronized atrial excitation or multi-site atrial stimulation, can help restore atrial synchrony and lead to better outcomes for these patients, including improved heart failure symptoms and potentially reduced atrial arrhythmia burden. One limitation is finding one or more desired sites for pacing therapy within the atrium that result in the expected improvement in bi-atrial synchrony.

[0023] The method disclosed includes: applying multiple surface electrodes (ECG bands) to a patient and processing P waves based on signals received from these electrodes to derive an atrial activation map; calculating a metric reflecting spatial electrical synchrony of the atria that can be used to assess natural atrial synchrony; and evaluating improvements in biatrial synchrony during pacing at different atrial sites. The target site on the atrium can be the Bachmann bundle, or other sites in the left or right atrium or the atrial septum. The endpoint of the atrial lead placement procedure can be defined when rapid diffusion of atrial activation is observed on the map during the procedure and the standard deviation of the activation time is below a certain threshold.

[0024] Figure 1 This is a schematic diagram of a system for determining the location of an atrial pacing lead for delivery in cardiac pacing therapy, according to this disclosure. Figure 1 An exemplary system 100 is depicted, including an electrode device 110, a display device 130, and a computing device 140. The illustrated electrode device 110 includes a plurality of electrodes incorporated into or included within a band wrapped around the chest or torso of a patient 120. The electrode device 110 is operatively coupled to the computing device 140 (e.g., via a wired or wired electrical connection, wirelessly, etc.) to provide electrical signals from each of the electrodes to the computing device 140 for analysis, evaluation, etc. An exemplary electrode device can be described in U.S. Patent No. 9,320,446, issued April 26, 2016, entitled “Bioelectric Sensor Device and Methods,” which is incorporated herein by reference in its entirety. Further, the exemplary electrode device 110 will be referred to... Figure 2-3 It was described in more detail.

[0025] Display device 130 and computing device 140 may be configured to display and analyze data, such as electrical signals (e.g., electrocardiogram data), cardiac information representing at least one of mechanical and electrical cardiac functions, etc. Cardiac information may include, for example, information on electrical heterogeneity or electrical asynchrony generated using electrical signals collected, monitored, or gathered using electrode device 110, surrogate electrical excitation information, or data. In at least one embodiment, computing device 140 may be a server, a personal computer, or a tablet computer. Computing device 140 may be configured to receive input from input device 142 and transmit output to display device 130. Further, computing device 140 may include data storage that may allow access to processes or routines and / or one or more other types of data, such as a graphical user interface configured to non-invasively assist a user in assessing pacing locations (e.g., the location of implanted electrodes for pacing, the location of pacing therapy delivered by a specific pacing vector, etc.).

[0026] Computing device 140 can be operatively coupled to input device 142 and display device 130 to, for example, transmit data to and from each of input device 142 and display device 130. For example, computing device 140 can be electrically coupled to each of input device 142 and display device 130 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 device 142 to manipulate or modify one or more graphic depictions displayed on display device 130 and view and / or select one or more pieces of information related to cardiac treatment.

[0027] Although the input device 142 depicted is a keyboard, it should be understood that the input device 142 may include any means capable of providing input to the computing device 140 to perform the functions, methods, and / or logic described herein. For example, the input device 142 may include a mouse, a trackball, a touchscreen (e.g., a capacitive touchscreen, a resistive touchscreen, a multi-touch touchscreen, etc.), etc. Similarly, the display device 130 may include any means capable of displaying information to a user, such as a graphical user interface 132, which may include cardiac information, text commands, graphical depictions of electrical excitation information, graphical depictions of the anatomy of the human heart, images or graphical depictions of a patient's heart, graphical depictions of the location of one or more electrodes, graphical depictions of the human torso, images or graphical depictions of a patient's torso, graphical depictions or actual images of implanted electrodes and / or leads, etc. Further, the display device 130 may include a liquid crystal display, an organic light-emitting diode screen, a touchscreen, a cathode ray tube display, etc.

[0028] The processing program or routine stored and / or executed by the computing device 140 may include programs or routines for: computational mathematics, matrix mathematics, dispersion determination (e.g., standard deviation, variance, range, interquartile range, mean absolute difference, mean absolute deviation, etc.), filtering algorithms, maximum value determination, minimum value determination, threshold determination, moving window algorithm, decomposition algorithm, compression algorithm (e.g., data compression algorithm), calibration algorithm, image construction algorithm, signal processing algorithm (e.g., various filtering algorithms, Fourier transform, fast Fourier transform, etc.), normalization algorithm, comparison algorithm, vector mathematics, or any other processing required to implement one or more exemplary methods and / or processes described herein. The data stored and / or used by the computing device 140 may include, for example, electrical signal / waveform data from the electrode device 110, scattered signals, windowed scattered signals, portions or parts of various signals, electrical excitation times from the electrode device 110, graphics (e.g., graphic elements, icons, buttons, windows, dialog boxes, drop-down menus, graphic areas, graphic regions, 3D graphics, etc.), graphical user interfaces, results from one or more processing procedures or routines adopted according to the disclosure herein (e.g., electrical signals, cardiac information, etc.), or any other data required for performing one or more processes or methods described herein.

[0029] In one or more embodiments, exemplary systems, methods, and interfaces may be implemented using one or more computer programs that execute on a programmable computer, such as a computer including, for example, processing power, data storage (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 used as input to one or more other devices and / or methods as described herein or as would be applied in a known manner.

[0030] One or more programs for implementing the systems, methods, and / or interfaces described herein can be provided using any programmable language, such as high-level procedural programming languages ​​and / or object-oriented programming languages ​​suitable for communicating with computer systems. Any such program can be stored, for example, on any suitable device (e.g., a storage medium) readable by a general-purpose or special-purpose program, which runs on a computer system (e.g., including a processing device) to configure and operate the computer system when the appropriate device is accessed to execute the programs described herein. That is, in at least one embodiment, exemplary systems, methods, and / or interfaces can be implemented using a computer-readable storage medium configured with computer programs, wherein the storage medium is so configured that the computer operates in a specific and predefined manner to perform the functions described herein. Further, in at least one embodiment, exemplary systems, methods, and / or interfaces can be described as being implemented by logic (e.g., object code) encoded in one or more non-transient media, which includes code for execution and operable, when executed by a processor, for performing operations such as the methods, processes, and / or functions described herein.

[0031] The computing device 140 can be, for example, any fixed or mobile computer system (e.g., a controller, microcontroller, personal computer, minicomputer, tablet computer, etc.) and can generally be described as including a processing circuitry system. The exact configuration of the computing device 140 is not limiting, and substantially any device capable of providing adequate computing and control capabilities (e.g., graphics processing, etc.) can be used. As described herein, a digital file can be any medium containing digital bits (e.g., encoded in binary, ternary, etc.) that can be read and / or written by the computing device 140 described herein (e.g., volatile or non-volatile memory, CD-ROM, punched card, magnetically readable medium such as a disk or magnetic tape, etc.). Similarly, as described herein, a user-readable format file can be any data representation (e.g., ASCII text, binary numbers, hexadecimal numbers, decimal numbers, graphics, etc.) that is user-readable and / or understandable and can be presented on any medium (e.g., paper, display, etc.).

[0032] In view of the foregoing, it will be apparent that the functionality described in one or more embodiments according to this disclosure can be implemented in any manner as would be known to those skilled in the art. Thus, computer languages, computer systems, or any other software / hardware that may be used to implement the processes described herein should not be limited to the scope of the systems, processes, or programs described herein (e.g., the functionality provided by such systems, processes, or programs).

[0033] The duration of electrical activation of the patient's heart can be useful for assessing the patient's cardiac condition and / or for delivering His bundle cardiac therapy to the patient. This can be achieved using methods such as... Figure 1 and Figure 2-3 The electrode device 110 shown is used to monitor or determine alternative electrical excitation information or data in one or more areas of a patient's heart. The exemplary electrode device 110 can be configured to measure the body surface potential of a patient 120, and more specifically, the torso surface potential of the patient 120. Figure 2 As shown, the exemplary electrode device 110 may include a set of electrodes 112 or an array of electrodes 112, a strap 113, and an interface / amplifier circuitry system 116. The electrodes 112 may be attached to or coupled to the strap 113, and the strap 113 may be configured to wrap around the torso of the patient 120, such that the electrodes 112 surround the patient's heart. As further shown, the electrodes 112 may be positioned around the periphery of the patient 120, including posterior, lateral, posterolateral, anterolateral, and anterior positions of the patient 120's torso.

[0034] Furthermore, electrode 112 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 provide these signals to computing device 140. Other exemplary systems may use wireless connections to transmit signals sensed by electrode 112 to interface / amplifier circuitry 116 and subsequently to computing device 140, for example, as multichannel data. For example, interface / amplifier circuitry 116 can be electrically coupled to each of computing device 140 and display device 130 using, for example, analog electrical connections, digital electrical connections, wireless connections, bus-based connections, network-based connections, internet-based connections, etc.

[0035] Despite Figure 2 In one example, electrode device 110 includes a bandage 113; however, in other examples, any of a variety of mechanisms (e.g., tape or adhesive) may be used to aid in the spacing and placement of electrodes 112. In some examples, bandage 113 may include an elastic band, tape strip, or cloth. In other examples, electrodes 112 may be placed individually on the torso of patient 120. Further, in other examples, electrodes 112 (e.g., arranged in an array) may be part of a patch, vest, or positioned within a patch, vest, and / or other means of securing electrodes 112 to the torso of patient 120.

[0036] Electrodes 112 can be configured to surround the heart of patient 120 and to record or monitor electrical signals associated with cardiac depolarization and repolarization after these signals have propagated through the torso of patient 120. Each of the electrodes 112 can be used in a unipolar configuration to sense the torso surface potential reflecting cardiac signals. An interface / amplifier circuitry 116 can also be coupled to a return electrode or neutral electrode (not shown) that can be used in combination with each electrode 112 for unipolar sensing. In some examples, there may be approximately 12 to approximately 50 electrodes 112 spatially distributed around the patient's torso. Other configurations may have more or fewer electrodes 112.

[0037] The computing device 140 can record and analyze electrical activity (e.g., trunk surface potential signals) sensed by the electrodes 112 and amplified / modulated by the interface / amplifier circuitry 116. The computing device 140 can be configured to analyze signals from the electrodes 112 to provide them as anterior electrode signals and posterior electrode signals, as well as alternative cardiac electrical activation times, which, for example, represent the actual or local electrical activation times of one or more areas of the patient's heart, as will be further described below. Furthermore, the electrical signal measured at the left anterior surface of the patient's trunk may represent, or be a substitute for, the electrical signal of the left anterior left ventricular region of the patient's heart; the electrical signal measured at the left lateral surface of the patient's trunk may represent, or be a substitute for, the electrical signal of the left lateral left ventricular region of the patient's heart; the electrical signal measured at the left posterolateral surface of the patient's trunk may represent, or be a substitute for, the electrical signal of the posterolateral left ventricular region of the patient's heart; and the electrical signal measured at the posterior surface of the patient's trunk may represent, or be a substitute for, the electrical signal of the posterior left ventricular region of the patient's heart. In one or more embodiments, the measurement of excitation time can be performed by measuring the time interval between the onset of cardiac depolarization (e.g., the onset of the QRS complex) and an appropriate reference point, such as, for example, a peak, a minimum, a minimum slope, a maximum slope, a zero crossing, a threshold crossing, etc.

[0038] Additionally, the computing device 140 may be configured to provide a graphical user interface depicting the alternative electrical activation time obtained using the electrode device 110. Exemplary systems, methods, and / or interfaces may non-invasively use the electrical information collected using the electrode device 110 to assess a patient's cardiac condition and / or for His bundle pacing therapy delivered to the patient.

[0039] Figure 3Another exemplary electrode device 110 is shown, comprising a plurality of electrodes 112 configured to surround the heart of a patient 120, and recording or monitoring electrical signals associated with depolarization and repolarization of the heart after these signals have propagated through the torso of the patient 120. The electrode device 110 may include a vest 114 to which the plurality of electrodes 112 may be attached, or the electrodes 112 may be coupled to the vest 114. In at least one embodiment, the plurality of electrodes 112 or an array of electrodes 112 may be used to collect electrical information, such as, for example, alternative electrical excitation times. Similar to... Figure 2 Electrode device 110, Figure 3 The electrode device 110 may include an interface / amplifier circuitry 116, which is electrically coupled to each of the electrodes 112 via a wired connection 118 and configured to transmit signals from the electrodes 112 to the computing device 140. As shown, the electrodes 112 may be distributed on the torso of the patient 120, including, for example, the anterior surface, lateral surface, posterolateral surface, anterolateral surface, and posterior surface of the torso of the patient 120.

[0040] Vest 114 may be formed of a woven fabric, with electrodes 112 attached to the fabric. Vest 114 may be configured to maintain the position and spacing of electrodes 112 on the torso of patient 120. Further, vest 114 may be marked to aid in determining the position of electrodes 112 on the torso surface of patient 120. In one or more embodiments, vest 114 may include 17 or more front electrodes positioned close to the anterior torso of patient, and may include 39 or more rear electrodes positioned close to the anterior torso of patient. In some examples, approximately 25 to approximately 256 electrodes 112 may be distributed around the torso of patient 120, but other configurations may have more or fewer electrodes 112.

[0041] Figure 4 This is a schematic diagram of an exemplary medical device for detecting cardiac arrhythmias according to embodiments of the present disclosure. Figure 4The medical device shown, according to an embodiment of this disclosure, can take the form of an implantable cardioverter-defibrillator (ICD) 10, which includes a connector block 12 102 receiving the proximal ends of a right ventricular lead 16, a right atrial lead 15, and a coronary sinus lead 6, which are used to position electrodes for sensing and stimulation in three or four heart chambers. The right ventricular lead 16 is positioned such that its distal end is in the right ventricle for sensing right ventricular cardiac signals and delivering pacing or shock pulses in the right ventricle. For these purposes, the right ventricular lead 16 is equipped with a ring electrode 24, a retractable helical electrode 26 retractably mounted within an electrode head 28, and a coil electrode 20, each of which is connected to an insulating conductor within the body of the lead 16. The proximal end of the insulating conductor is coupled to a corresponding connector carried by a bifurcated connector 14 at the proximal end of the lead 16 for providing electrical connection to the ICD 10. It should be understood that, although Figure 1 The device shown is a dual-chamber device, but other devices (such as single-chamber devices) can be used to perform the techniques described herein.

[0042] The right atrial lead 15 is positioned such that its distal end is near the right atrium and superior vena cava. Lead 15 is equipped with a ring electrode 21 for sensing and pacing in the right atrium and a retractable helical electrode 17, which is retractably mounted within an electrode head 19. Lead 15 is further equipped with a coil electrode 23 for delivering high-energy electrical shock therapy. The ring electrode 21, helical electrode 17, and coil electrode 23 are each connected to an insulated conductor within the body of the right atrial lead 15. Each insulated conductor is coupled at its proximal end to a connector carried by a bifurcated connector 13.

[0043] The coronary sinus suture 6 travels through the coronary sinus and the great cardiac vein within the vascular system on the left side of the heart. Figure 4In one embodiment, the coronary sinus lead 6 is shown with a defibrillation coil electrode 8, which can be used in combination with coil electrode 20 or coil electrode 23 to deliver an electric shock for cardioversion and defibrillation therapy. In other embodiments, the coronary sinus lead 6 may also be equipped with a distal tip electrode and a loop electrode for pacing and sensing functions in the left ventricle of the heart. The coil electrode 8 is coupled to an insulated conductor within the body of the lead 6, which provides connection to the proximal connector 4. Electrodes 17 and 21 or 24 and 26 can be used as a true bipolar pair (commonly referred to as a "tip-to-loop" configuration). Furthermore, electrode 17 and coil electrode 20 or electrode 24 and coil electrode 23 can be used as an integrated bipolar pair, commonly referred to as a "tip-to-coil" configuration. According to the invention, the ICD 10 can, for example, adjust the electrode configuration from a tip-to-loop configuration (e.g., true bipolar sensing) to a tip-to-coil configuration (e.g., integrated bipolar sensing) upon detection of oversensing in order to reduce the likelihood of future oversensing. In other words, the electrode polarity can be reselected in response to the detection of oversensing in an effort to reduce susceptibility to oversensing. In some cases, electrodes 17, 21, 24, and 26 can be used individually in a monopolar configuration, wherein the device housing 11 acts as the neutral electrode, often referred to as the "can" or "casing" electrode.

[0044] The device housing 11 can also be used in combination with one or more of the defibrillation coil electrodes 8, 20, or 23 to serve as a subcutaneous defibrillation electrode for defibrillating the atria or ventricles. It should be recognized that alternative lead systems can be used instead of... Figure 4 The three-lead system shown. Although in Figure 4 The invention illustrates a specific multi-chamber ICD and lead system, but the methods included in this invention can be adapted for use with any single-chamber, dual-chamber, or multi-chamber ICD or pacemaker system, subcutaneous implantable device, or other internal or external cardiac monitoring device.

[0045] The ICD 10 can alternatively be configured as a subcutaneous device having sensing or pacing electrodes incorporated into the housing 11 of the device, in which case no transvenous lead is required. The subcutaneous device can be coupled to a subcutaneous or submuscular lead for delivering transthoracic pacing pulses and / or sensing ECG signals. Exemplary subcutaneous devices are described in commonly assigned U.S. Patent Application Serials 14 / 604,111 and 14 / 604,260. The techniques described herein can also be implemented in external devices, such as those including patch electrodes and optionally another physiological sensor (if desired), which can sense the variable parameters as described herein.

[0046] Figure 5 yes Figure 4This is a functional schematic diagram of a medical device. This diagram should be considered as an example of the types of devices that may embody the invention and is not intended to be limiting. Figure 5 The disclosed embodiments shown are microprocessor-controlled devices, but other types of devices (such as devices employing dedicated digital circuitry systems) can also be used to practice the methods of the invention.

[0047] for Figure 4 The electrode system shown, ICD 10, is provided with multiple connection terminals for making electrical connections to leads 6, 15, and 16 and their respective electrodes. Connection terminal 311 provides an electrical connection to housing 11, which serves as a neutral electrode during monopolar stimulation or sensing. Connection terminals 320, 313, and 318 provide electrical connections to coil electrodes 20, 8, and 23, respectively. Each of these connection terminals 311, 320, 313, and 318 is coupled to a high-voltage output circuit 234 to facilitate the delivery of high-energy electrical shock pulses to the heart using one or more of the coil electrodes 8, 20, and 23, and optionally housing 11.

[0048] Connection terminals 317 and 321 provide electrical connections to the helical electrode 17 and the ring electrode 21 positioned in the right atrium. Connection terminals 317 and 321 are further coupled to the atrial sensing amplifier 204 for sensing atrial signals (such as P waves). Connection terminals 326 and 324 provide electrical connections to the helical electrode 26 and the ring electrode 24 positioned in the right ventricle. Connection terminals 326 and 324 are further coupled to the ventricular sensing amplifier 200 for sensing ventricular signals.

[0049] The atrial sensing amplifier 204 and ventricular sensing amplifier 200 are preferably in the form of automatic gain control amplifiers with adjustable sensitivity. According to the invention, ICD 10, and more specifically, microprocessor 224 automatically adjusts the sensitivity of the atrial sensing amplifier 204, ventricular sensing amplifier 200, or both, in response to the detection of oversensing, in order to reduce the likelihood of oversensing. The ventricular sensing amplifier 200 and atrial sensing amplifier 204 operate for multiple cardiac cycles according to originally programmed sensing parameters, and automatically provide corrective action to avoid future oversensing when oversensing is detected. In this way, the adjustments provided by ICD 10 to amplifiers 200 and 204 to avoid future oversensing are inherently dynamic. Specifically, when oversensing is detected, microprocessor 224 increases the sensitivity value of the amplifier, thereby reducing the sensitivity. The atrial sensing amplifier 204 and ventricular sensing amplifier 200 receive timing information from the pacemaker timing and control circuitry system 212.

[0050] Specifically, the atrial sensing amplifier 204 and the ventricular sensing amplifier 200 can receive a blanking period input (e.g., ABLANK (A blanking) and VBLANK (V blanking), respectively), which instructs the electrodes to be "disconnected" to prevent saturation due to the applied pacing pulse or defibrillation shock. The blanking periods of the atrial sensing amplifier 204 and the ventricular sensing amplifier 200 can be automatically adjusted by the ICD 10, and consequently, the blanking periods of the sensing electrodes associated with the respective amplifiers, to reduce the likelihood of oversensing. The general operation of the ventricular sensing amplifier 200 and the atrial sensing amplifier 204 can correspond to the general operation disclosed in U.S. Patent No. 5,117,824 (Keimel et al.). Whenever the signal received by the atrial sensing amplifier 204 exceeds the atrial sensitivity, a signal is generated on the P-out (P-output) signal line 206. Whenever the signal received by the ventricular sensing amplifier 200 exceeds the ventricular sensitivity, a signal is generated on the R-out (R-output) signal line 202.

[0051] Switch matrix 208 is used to select which of the available electrodes are coupled to broadband amplifier 210 for digital signal analysis. Electrode selection is controlled by microprocessor 224 via data / address bus 218. The selected electrode configuration can be changed according to the various sensing, pacing, cardioversion, and defibrillation functions of ICD 10. Specifically, microprocessor 224 can modify the electrode configuration based on the detection of oversensing due to cardiac or non-cardiac origin. For example, upon detection of R-wave oversensing, microprocessor 224 can modify the right ventricular electrode configuration from true bipolar sensing (e.g., tip-to-loop) to integrated bipolar sensing (e.g., tip-to-coil).

[0052] Signals from electrodes selected for coupling to bandpass amplifier 210 are provided to multiplexer 220 and subsequently converted into multi-bit digital signals by A / D converter 222 for storage in random access memory 228 via data / address bus 218 under the control of direct memory access circuitry 226. Microprocessor 224 may employ digital signal analysis techniques to characterize the digitized signals stored in random access memory 226 in order to identify and classify a patient's heart rhythm using any of the numerous signal processing methods known in the art. An exemplary tachyarrhythmia identification system is described in U.S. Patent No. 5,545,186 to Olson et al.

[0053] When an arrhythmia is detected, the episode from the EGM data, along with corresponding annotations of the sensed interval and the sensed event, is preferably stored in random access memory 226. The stored EGM signal can be sensed from programmed near-field and / or far-field sensing electrode pairs. Typically, near-field sensing electrode pairs include tip and loop electrodes located in the atrium or ventricle, such as electrodes 17 and 21 or electrodes 26 and 24. Far-field sensing electrode pairs include electrodes spaced further apart, such as any of the following pairs: defibrillator coil electrodes 8, 20, or 23 with housing 11; tip electrode 17 or 26 with housing 11; tip electrode 17 or 26 with defibrillator coil electrode 20 or 23; or atrial tip electrode 17 with ventricular loop electrode 24. The use of near-field and far-field EGM sensing for arrhythmia episodes is described in U.S. Patent No. 5,193,535 to Bardy. Annotations for sensed events that can be displayed and stored along with EGM data are described in U.S. Patent No. 4,374,382, granted to Markowitz.

[0054] Telemetry circuitry 330 receives downlink telemetry from an external programmer (as is common in implantable antiarrhythmic devices) via antenna 332 and transmits uplink telemetry to the external programmer. Data to be transmitted uplink to the programmer and control signals for the telemetry circuitry are provided by microprocessor 224 via address / data bus 218. Telemetry circuitry 330 can be used to transmit stored EGM data to the external programmer during arrhythmia detection or when triggered by other monitoring algorithms. The received telemetry is provided to microprocessor 224 via multiplexer 220. Many types of telemetry systems known in the art for implantable devices can be used.

[0055] Figure 5 The remainder of the circuitry shown is an exemplary embodiment of a circuitry system specifically designed to provide cardiac pacing, cardioversion, and defibrillation therapy. The pacemaker timing and control circuitry 212 includes a programmable digital counter that controls the fundamental time intervals associated with various single-chamber, dual-chamber, or multi-chamber pacing modes or anti-tachycardia pacing therapies delivered in the atrium or ventricle. The pacemaker circuitry 212 also determines the amplitude of the cardiac pacing pulses under the control of a microprocessor 224.

[0056] During pacing, the escape interval counter within the pacemaker timing and control circuitry system 212 is reset upon sensing an R wave and a P wave, as indicated by signals on lines 202 and 206, respectively. Depending on the selected pacing mode, pacing pulses are generated by the atrial pacemaker output circuit 214 and the ventricular pacemaker output circuit 216. Pacemaker output circuits 214 and 216 are coupled to the desired electrode via a switch matrix 208 for pacing. The escape interval counter is reset upon generating the pacing pulse, thereby controlling the basic timing of cardiac pacing functions, including antitachycardia pacing.

[0057] The duration of the escape interval is determined by the microprocessor 224 via the data / address bus 218. When the escape interval counter is reset by a sensed R wave or P wave, the count value present in the escape interval counter can be used to measure the RR interval and PP interval for the detection of various arrhythmias.

[0058] The microprocessor 224 includes an associated read-only memory (ROM) in which a program controlling the operation of the microprocessor 224 resides. A portion of the random access memory (RAM) 226 may be configured as a plurality of recirculation buffers capable of maintaining a series of measured intervals for analysis by the microprocessor 224 to predict or diagnose arrhythmias.

[0059] In response to the detection of tachycardia, anti-tachycardia pacing therapy can be delivered by loading a protocol from microprocessor 224 into pacemaker timing and control circuitry system 212 according to the type of tachycardia detected. In cases requiring higher-voltage cardioversion or defibrillation pulses, microprocessor 224 activates cardioversion and defibrillation control circuitry system 230 to initiate charging of high-voltage capacitors 246 and 248 via charging circuitry 236 under the control of high-voltage charging control line 240. The voltage on the high-voltage capacitors is monitored via voltage capacitor line (VCAP) 244, which passes through multiplexer 220. When the voltage reaches a predetermined value set by microprocessor 224, a logic signal is generated on capacitor fully charged (CF) line 254, thereby terminating charging. Defibrillation and cardioversion pulses are delivered to the heart via control bus 238 by output circuitry 234 under the control of pacemaker timing and control circuitry system 212. Output circuit 234 determines the electrodes and pulse waveforms used to deliver cardiac cardioversion or defibrillation pulses.

[0060] In one example, the ICD 10 may be equipped with a patient notification system 150. Any patient notification system known in the art can be used for purposes such as generating a perceived twitching stimulus or an audible sound. The patient notification system may include an audio transducer that emits audible sounds, including audible statements or musical tones stored in analog memory and associated with programmed or querying operating algorithms or with warning-triggered events as generally described in U.S. Patent No. 6,067,473 to Greeninger et al.

[0061] As described herein, electrode device 110 can be configured to measure electrical information (e.g., electrical signals) representing different regions of a patient's heart. For example, the activation time of different regions of a patient's heart can be roughly estimated based on the activation time of surface electrocardiogram (ECG) measured using surface electrodes near surface regions corresponding to different regions of the patient's heart.

[0062] Exemplary systems, methods, and interfaces can be used to provide non-invasive assistance to users when assessing a patient’s cardiac health or condition and / or assessing the delivery of cardiac treatments (such as atrial pacing therapy performed using electrode device 110, for example, cardiac treatment currently delivered to the patient during or after implantation).

[0063] Patients with atrial dyssynchrony may experience wide P waves and slower atrial conduction, which can lead to delayed atrial expulsion and a reduced contribution of atrial expulsion to cardiac filling, impairing ventricular function (heart failure). Atrial dyssynchrony can also be a cause of atrial arrhythmias and atrial fibrillation. Atrial pacing therapy can be used to help restore atrial synchrony and lead to better outcomes for these patients, including relief of heart failure symptoms and potentially reduced burden of atrial arrhythmias. In the heart's conduction system, the Bachmann bundle (also known as the interatrial tract or Bachmann bundle) is a branch of the anterior internodal tract residing on the inner wall of the left atrium and is a broad band of myocardium passing from the right atrium between the right vena cava and the ascending aorta. The Bachmann bundle is considered the preferred pathway for left atrial electrical excitation during normal sinus rhythm and is therefore considered part of the heart's "atrial conduction system." Therefore, atrial pacing using a single lead in the atrium targeting the Bachmann bundle for synchronized atrial activation can be used to treat atrial dyssynchrony. Another possible pacing treatment for atrial dyssynchrony may include multi-site atrial stimulation using two leads, one positioned in the right atrium and the other in the left atrium.

[0064] One limitation of using this pacing therapy to address atrial dyssynchrony is that it may involve finding one or more desired locations within one atrium during Bachmann bundle pacing, or one or more desired locations within both atria during bi-atrial pacing, to deliver pacing therapy that results in an overall improvement in bi-atrial synchrony. According to this disclosure, a method is disclosed that includes applying multiple surface electrodes (ECG bands) to a patient and processing P waves from those electrodes to derive an atrial activation map and calculating a metric reflecting spatial electrical dyssynchrony of the atria, which can be used to assess both natural atrial dyssynchrony and improvements in bi-atrial synchrony during pacing at different atrial sites. The target site on the atria may be the Bachmann bundle, or it may be another site in the left or right atrium. The endpoint of the atrial lead placement procedure can be defined when rapid diffusion of atrial activation is observed on the atrial activation map generated from the ECG bands. For example, the endpoint of the atrial lead placement procedure can be defined when a metric reflecting spatial electrical dyssynchrony of the atria (such as, for example, the standard deviation of activation time) is determined to be within or below a certain threshold.

[0065] Figure 6 This is a flowchart illustrating a method for determining a metric for assessing atrial lead placement based on examples of this disclosure. Figure 6 As shown, to evaluate the placement of the atrial lead for delivery of atrial pacing therapy, when the electrode device 110 is worn by the patient, the computing device 140, for example using the display device 130, identifies the occurrence of the intrinsic rhythm (box 400) and processes the signals sensed from each of the external electrodes 112 during the intrinsic rhythm (box 402). The computing device 140 determines the P-wave excitation of the intrinsic rhythm based on the signals sensed via each of the external electrodes 112 (box 404). Instead of determining the P-wave excitation within a single atrial chamber, the computing device 140 determines the P-wave excitation signals passing through both the left and right atria of the heart, i.e., biatrial excitation (box 404). The computing device 140 then determines a measure of biatrial asynchrony based on the determined intrinsic P waves (box 406).

[0066] Figure 7 This is a schematic diagram illustrating the determination of P-wave activation according to an example of this disclosure. In one example, the measure of atrial dyssynchrony determined in box 406 can be based on: the standard deviation of activation time for a given determined P-wave. For example, as... Figure 7 As shown, during the determination of P-wave excitation ( Figure 6 (in block 404), the computing device 140 determines the P-wave window 510 of the signal 502 based on, for example, the change in amplitude of the signal 502 sensed from each of the plurality of electrodes 112.

[0067] like Figure 7As shown, before the P-wave window 500, all sensed signals 502 are relatively flat, indicating that no P-wave is detected. During the detection of P-wave excitation, the amplitudes of some signals 504 from the corresponding electrodes 112 tend to increase, while the amplitudes of other signals 506 tend to remain constant. Therefore, according to an example of this disclosure, the computing device 140 senses the ECG signals 502 from each of the electrodes 112 and determines whether there is an increase in the amplitude of a predetermined number of sensed signals 502. The P-wave window 510 is defined to have a start point 512 and an end point 514, whereby the start point 512 is determined to have occurred once there is an increase in the amplitude of a predetermined number of sensed signals 502, and the end point 514 is determined to have occurred once there is a decrease in the amplitude of a predetermined number of sensed signals 512.

[0068] The P-wave activation time at each electrode is determined based on the interval between the start of the window and a reference point of the P-wave signal sensed at that particular electrode within the time window. The reference point may be a point corresponding to the steepest negative slope of the P-wave signal. A surface isochronous map of atrial electrical activation is generated based on the activation time of the sensed signal 502 sensed during the P-wave window 510. The electrical heterogeneity information generated from the surface isochronous map is then used to determine the distribution of atrial activation, thereby enabling the determination of a measure of biatrial synchrony / asynchrony in response to the determined distribution of atrial activation (box 406), as described below.

[0069] Figure 8 This is an exemplary illustration generated based on the distribution of atrial activation information according to examples of this disclosure. Figure 8 As shown, the computing device 140 generates an isochronous diagram 600 based on the electrical excitation occurring within the determined P-wave time window 510. This isochronous diagram 600 depicts the distribution of biventricular excitation time along the anterior and posterior sides of the patient's trunk during atrial depolarization. The isochronous diagram 600 shows the distribution along the anterior side 520 of the patient (also...). Figure 7 The electrode 112, as shown in the diagram, is positioned with an excitation spread 602 from right to left, and along the posterior side of the patient 522 (also shown in the diagram). Figure 7 The excitation distribution of electrode 112 (shown in the figure) is 604 from right to left.

[0070] The presence of darker portions of excitation dispersions 602 and 604 indicates excitation delay 606 (which results in a longer or slower conduction time). Figure 8In the example shown, the excitation spread 604 along the posterior side 522 of the patient includes a larger, darker portion, which indicates a larger excitation delay 606 relative to the excitation delay 606 along the anterior side 520. As a result, the atrial dyssynchrony fraction is indicated by the deviation between the excitation delay 606 associated with the excitation spread 602 along the anterior side 520 and the excitation delay 606 associated with the excitation spread 604 along the posterior side 522.

[0071] For example, suppose the P-wave excitation times from the twenty electrodes associated with the isochronous diagram of the front side 520 are 10ms, 10ms, 12ms, 14ms, 16ms, 18ms, 20ms, 24ms, 25ms, 27ms, 31ms, 34ms, 37ms, 38ms, 40ms, 41ms, 42ms, 44ms, 45ms, and 5ms, and the excitation times from the twenty electrodes associated with the isochronous diagram of the rear side 522 are 67ms, 72ms, 77ms, 81ms, 81ms, 100ms, 105ms, 112ms, 115ms, 120ms, 120ms, 121ms, 76ms, 21ms, 22ms, 18ms, 19ms, 19ms, 18ms, and 18ms, in Figure 6 In block 406, the measure of atrial dyssynchrony determined for the identified intrinsic P wave is defined as the standard deviation of the combined anterior and posterior P wave activation times, which is 36 ms in this particular example. The computing device 140 stores the determined measure of atrial dyssynchrony during the intrinsic rhythm, i.e., 36 ms. In another embodiment, the measure of atrial dyssynchrony may be based on the difference between the mean anterior and mean posterior P wave activation times. Other statistical measures of heterogeneity and dispersion may be applied to the set of anterior and posterior P wave activation times to generate the measure of atrial dyssynchrony.

[0072] Figure 9 This is a flowchart illustrating a method for determining atrial lead placement for delivery of atrial pacing therapy, according to an example of this disclosure. According to one example of this disclosure, once the measure of bi-atrial asynchrony during the intrinsic rhythm is determined as described above (…),… Figure 6 In box 406), multiple body surface electrodes of the electrode device (ECG band) 110 positioned on the patient as described above are used to perform placement of one or more leads in one or two of the atrial chambers for delivery of atrial pacing therapy. For example, as Figure 9As shown, lead placement can begin by positioning one or more leads at one or more target sites (box 620), such as positioning a single lead near or adjacent to the Bachmann bundle, for example, positioning a single lead at another location within the right or left atrium, or using two leads, one positioned within the right atrium and the second within the left atrium. During subsequent delivery of atrial pacing therapy, external electrodes 112 of the electrode device 110 as described above sense electrical excitation information associated with the patient's heart, and computing device 140 determines the P-wave excitation at the current lead location based on the signals sensed via each of the external electrodes 112 (box 622) (box 624). In the same manner as described above in the use of inherent atrial rhythm, the computing device 140, during the subsequent placement of one or more leads, does not determine the P-wave excitation in a single atrial chamber, but rather determines the P-wave excitation signals of both the left and right atria passing through the heart, i.e., biatrial excitation (box 624).

[0073] Once P-wave excitation is determined (box 624), the computing device 140 then determines the distribution of atrial excitation based on the determined P-wave excitation (box 624) (box 626) and determines the atrial dyssynchrony fraction associated with the current position of one or more leads (box 628). Based on the determined atrial dyssynchrony fraction (box 628), the computing device 140 determines whether the current atrial dyssynchrony fraction results in a predetermined reduction of atrial dyssynchrony (box 630). If the current atrial dyssynchrony fraction does not result in a reduction of atrial dyssynchrony ("No" in box 630), one or both of the two leads are repositioned (box 620), and the process is repeated for one or more leads that are in the adjusted position.

[0074] If the current atrial dyssynchrony fraction results in a decrease in atrial dyssynchrony ("Yes" in box 630), the computing device 140 determines whether the lead placement endpoint has been reached (box 632). If it is determined that the lead placement endpoint has not been reached ("No" in box 632), a single lead, or one or both of the two leads, is repositioned (box 620), and the process is repeated for one or more leads that are in the adjusted position. If it is determined that the lead placement endpoint has been reached ("Yes" in box 632), the current lead position is determined to be satisfactory for the delivery of atrial dyssynchrony pacing (box 634).

[0075] During the determination of whether the current atrial dyssynchrony fraction results in a desired change in atrial dyssynchrony (box 630), the computing device 140 determines whether the current atrial dyssynchrony fraction for one or more leads results in a predetermined reduction in dyssynchrony. For example, if the measure of biventricular dyssynchrony determined during the intrinsic rhythm is 36 ms, the computing device determines whether the current biventricular dyssynchrony fraction (box 628) corresponds to (i.e. results in) a predetermined percentage reduction in intrinsic biventricular dyssynchrony (box 630). In one example, the predetermined percentage could be, for example, between 15% and 20% reduction in biventricular dyssynchrony (i.e., a 20% reduction in the atrial dyssynchrony fraction during an intrinsic rhythm of 36 ms). Therefore, if a 20% reduction is determined to have occurred ("Yes" in box 630), it is determined that the lead placement endpoint has been reached ("Yes" in box 632). On the other hand, if it is determined that no 20% reduction has occurred (No in box 630), it is determined that the lead placement endpoint has not yet been reached (No in box 632), and the lead placement is adjusted (box 620) and the process is repeated for the adjusted lead placement.

[0076] In another embodiment, during the determination of whether the lead placement endpoint has been reached for the placement of a single lead near the Bachmann bundle (box 632), once the position of the lead near the Bachmann bundle results in a desired change in atrial asynchrony ("Yes" in box 630), the process continues by determining the positioning of another lead configuration. For example, computing device 140 may determine the fraction of atrial asynchrony for positioning the single lead in either the right or left atrium, or for positioning the single lead in both the right and left atrium, and repeat the process for that lead placement.

[0077] Once a fraction of atrial dyssynchrony is determined for a single lead positioned in the right or left atrium, or for two single leads (one in the right atrium and the second in the left atrium), the computing device 140 determines whether a desired change in atrial dyssynchrony exists (box 630) and repeats this process until the positioning of one or more leads results in a desired change in atrial dyssynchrony ("Yes" in box 630). This determined change in atrial dyssynchrony is then compared to a change in atrial dyssynchrony determined for a lead positioned near the Bachmann bundle. A determination is then made of which lead placement would result in the largest change in atrial dyssynchrony. For example, if the expected variation in atrial dyssynchrony determined for a lead positioned near the Bachmann bundle (box 630) is greater than the expected variation in atrial dyssynchrony determined for a single lead positioned in the right or left atrium, or for two single leads (one positioned in the right atrium and the second in the left atrium) (box 630), then the lead positioned near the Bachmann bundle is selected as the lead endpoint and used to deliver atrial pacing therapy, and vice versa.

[0078] In another embodiment, during the determination of whether the lead placement endpoint has been reached (box 632), in the example of placing a single lead near the Bachmann bundle, if the determination of a desired change in asynchrony between the two atria during lead placement (box 630) is not satisfied for a predetermined number of attempts, the computing device 140 may generate an alarm to indicate that lead placement near the Bachmann bundle has failed, and repeat the process using alternative lead placements (such as a single lead being positioned in the right or left atrium), or using two single leads (one positioned in the right atrium and the second in the left atrium). The predetermined number of attempts may be, for example, 5 attempts, 10 attempts, 15 attempts, or 20 attempts.

[0079] In this way, the computing device 140 can determine which lead placement configuration results in the greatest variation in asynchrony and select that lead placement configuration for the placement of one or more atrial leads. It should be understood that the computing device 140 can also make this determination among any number of possible lead placement configurations. For example, the determination can be made between: a single lead being positioned near the Bachmann bundle versus a single lead being positioned in either the left or right atrium, or in the atrial septum; a single lead being positioned in the right atrium versus a single lead being positioned in the left atrium; and a single lead being positioned in both the right and left atriums versus a single lead being positioned in either the left or right atrium, and so on.

[0080] As a result, this disclosure enables the correction of atrial dyssynchrony using any of a variety of different lead placement applications to help achieve more targeted atrial lead placement. Furthermore, this lead placement can have many different applications, including diastolic heart failure, systolic heart failure, and patients experiencing atrial fibrillation. Additionally, this information can be used in real-time procedures to aid in targeted atrial placement, particularly for engaging electrical activation across the entire atrial conduction system. In post-implantation settings, atrial activation maps and measurements of bi-atrial synchronization can be used to manage atrial dyssynchrony, which may include the titration of device parameters such as pacing output, pacing rate, pacing vector, and timing between sequential pacing pulses (if more than one pacing lead is involved).

[0081] The exemplary systems, methods, and graphical user interfaces described herein can be used with reference to the implantation and configuration of an implantable medical device (IMD) and / or one or more leads that are configured to be positioned close to one or more parts of a patient’s heart (e.g., close to the His bundle).

[0082] The technologies described in this disclosure (including those attributable to the ICD 10, computing device 140, and / or various 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 circuitry systems, and any combination of such components embodied in a programmer (such as a doctor programmer or patient programmer, a stimulator, an image processing device, or other device). The terms “module,” “processor,” or “processing circuitry system” generally refer to any of the aforementioned logic circuitry systems, either independently or in conjunction with other logic circuitry systems, or any other equivalent circuitry system.

[0083] 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 of the described units, modules, or components may be implemented together or separately as discrete but interoperable logical devices. Describing different features as modules or units is intended to emphasize different functional aspects and does not necessarily imply that such modules or units must be implemented by separate hardware or software components. Rather, the functions associated with one or more modules or units may be performed by separate hardware or software components or may be integrated within common or separate hardware or software components.

[0084] When implemented in software, the functionality attributable to the systems, devices, and techniques described in this disclosure can be embodied as instructions on a computer-readable medium (such as RAM, ROM, NVRAM, EEPROM, flash memory, magnetic data storage medium, optical data storage medium, etc.). These instructions can be executed by one or more processors to support one or more aspects of the functionality described in this disclosure.

[0085] This disclosure has been provided with reference to illustrative embodiments and is not intended to be interpreted in a limiting sense. As previously described, those skilled in the art will recognize that various other illustrative applications can be used to utilize the beneficial features of the apparatus and methods described herein. Various modifications to the illustrative embodiments and additional embodiments of this disclosure will become apparent upon reference to this specification.

[0086] Illustrative Examples

[0087] Example 1: A method for positioning an atrial pacing lead for delivery in cardiac pacing therapy, comprising:

[0088] Sense the electrical activity of the patient's tissues using multiple external electrodes;

[0089] In response to perceived electrical activity, the distribution of atrial excitation is determined;

[0090] In response to the determined distribution of atrial excitation, the changes in asynchrony between the two atria are determined;

[0091] In response to identified changes in atrial asynchrony, the target site for delivering atrial pacing therapy is adjusted; and

[0092] In response to this adjustment, the placement of the atrial pacing lead was determined for delivery of atrial pacing therapy.

[0093] Example 2: The method of Example 1 further includes:

[0094] The increase in the amplitude of the sensed electrical activity of a predetermined number of electrodes out of a plurality of electrodes is determined;

[0095] Determine the reduction in the amplitude of the sensed electrical activity of a predetermined number of electrodes out of a plurality of electrodes;

[0096] Electrical excitation information is generated based on the perceived electrical activity within a window extending between a determined increase and a determined decrease in amplitude; and

[0097] In response to electrical excitation information, the distribution and electrical heterogeneity of atrial excitation are determined.

[0098] Example 3: The method of any one of Examples 1-2, further comprising:

[0099] The first set of excitation times corresponding to the rear electrode group is determined based on the electrical activity sensed within the window.

[0100] The second set of excitation times corresponding to the front electrode group is determined based on the electrical activity sensed within the window.

[0101] For the combination of the first and second sets of excitation times, determine the standard deviation of the excitation time; and

[0102] The atrial dyssynchrony fraction is determined in response to the established standard deviation.

[0103] Example 4: A method for placing an atrial pacing lead for delivery in cardiac pacing therapy, comprising:

[0104] Perform at least one of the following: positioning a single lead near the Bachmann bundle, positioning a single lead in the right atrium, positioning a single lead in the left atrium, positioning a single lead in the atrial septum, and positioning a single lead in both the right and left atrium.

[0105] In response to the positioning, atrial pacing therapy is delivered;

[0106] In response to delivered atrial pacing therapy, electrical activity in the patient's tissues is sensed from multiple external electrodes;

[0107] In response to perceived electrical activity, the distribution of atrial excitation is determined;

[0108] In response to the determined distribution of atrial excitation, determine whether there are expected changes in atrial dyssynchrony;

[0109] Determine whether the lead placement endpoint has been reached; and

[0110] In response to reaching the lead placement endpoint, the target site for delivering atrial pacing therapy is determined.

[0111] Example 5: The method of Example 4 further includes:

[0112] The determined distribution of biatrial excitations was compared with the distribution of biatrial excitations in the intrinsic rhythm; and

[0113] In response to this comparison, it is determined whether there is a desired change in asynchrony between the two atria.

[0114] Example 6: The method of any one of Examples 4-5, further comprising:

[0115] The increase in the amplitude of the sensed electrical activity of a predetermined number of electrodes out of a plurality of electrodes is determined;

[0116] Determine the reduction in the amplitude of the sensed electrical activity of a predetermined number of electrodes out of a plurality of electrodes;

[0117] Information on the electrical heterogeneity of perceived electrical activity is generated within a window extending between a defined increase and a defined decrease in amplitude; and

[0118] The distribution of biatrial excitation is determined in response to information on electrical heterogeneity.

[0119] Example 7: The method of Example 6 further includes:

[0120] The first set of excitation times corresponding to the rear electrode group is determined based on the electrical activity sensed within the window.

[0121] The second set of excitation times corresponding to the front electrode group is determined based on the electrical activity sensed within the window.

[0122] For the combination of the first and second sets of excitation times, determine the standard deviation of the excitation time; and

[0123] The atrial dyssynchrony fraction is determined in response to the established standard deviation.

[0124] Example 8: The method of Example 7 further includes:

[0125] The determined atrial asynchrony fraction was compared with the atrial asynchrony fraction of the intrinsic rhythm.

[0126] Determine whether the atrial dyssynchrony fraction corresponds to a predetermined decrease in the atrial dyssynchrony fraction of the intrinsic rhythm; and

[0127] In response to the asynchrony fraction of the two atria corresponding to the predetermined decrease, it is determined that the lead placement endpoint has been reached.

[0128] Example 9: The method of any one of Examples 7-8, further comprising:

[0129] The determined atrial asynchrony fraction was compared with the atrial asynchrony fraction of the intrinsic rhythm.

[0130] In response to this comparison, changes in asynchrony between the two atria are identified;

[0131] The expected change in determining the presence of atrial asynchrony is in response to changes in atrial asynchrony identified for two or more of the following: positioning a single lead near the Bachmann bundle, positioning a single lead in the right atrium, positioning a single lead in the left atrium, positioning a single lead in the atrial septum, and positioning a single lead in both the right and left atrium; and

[0132] The endpoint of lead placement is determined by comparing two or more identified changes in atrial dyssynchrony that are associated with the expected change in atrial dyssynchrony.

[0133] Example 10: The method of any one of Examples 4-9, further comprising:

[0134] Determine that there is no expected change in atrial dyssynchrony for at least one of the following currently performed: positioning a single lead near the Bachmann bundle, positioning a single lead in the right atrium, positioning a single lead in the left atrium, positioning a single lead in the atrial septum, and positioning a single lead in both the right and left atrium.

[0135] Determine the desired change for performing another of the following: positioning a single lead near the Bachmann bundle, positioning a single lead in the right atrium, positioning a single lead in the left atrium, positioning a single lead in the atrial septum, and positioning a single lead in both the right and left atrium; and

[0136] The endpoint of lead placement is determined in response to a desired change in atrial synchrony for another of the following: positioning a single lead near the Bachmann bundle, positioning a single lead in the right atrium, positioning a single lead in the left atrium, positioning a single lead in the atrial septum, and positioning a single lead in both the right and left atrium.

[0137] Example 11: A system for determining the location of an atrial pacing lead for delivery in cardiac pacing therapy, comprising:

[0138] Multiple external electrodes are used to sense the electrical activity of the patient's tissues; and

[0139] A computing device configured to: determine the distribution of bi-atrial excitation in response to sensed electrical activity; determine changes in bi-atrial asynchrony in response to the determined distribution of bi-atrial excitation; adjust the target site for delivery of atrial pacing therapy in response to the determined changes in bi-atrial asynchrony; and determine the placement of an atrial pacing lead for delivery of atrial pacing therapy in response to the adjustment.

[0140] Example 12: The system of Example 11, wherein the computing device is configured to: determine an increase in the amplitude of the sensed electrical activity of a predetermined number of electrodes among a plurality of electrodes; determine a decrease in the amplitude of the sensed electrical activity of a predetermined number of electrodes among a plurality of electrodes; generate electrical heterogeneity information of the sensed electrical activity within a window extending between the determined increase in amplitude and the determined decrease in amplitude; and determine the distribution of biatrial excitation in response to the electrical heterogeneity information.

[0141] Example 13: A system of any one of Examples 11-12, wherein the computing device is configured to: determine a first excitation delay corresponding to the posterior excitation spread of sensed electrical activity within the window; determine a second excitation delay corresponding to the anterior excitation spread of sensed electrical activity within the window; determine a deviation between the first excitation delay and the second excitation delay; and determine the biatrial asynchrony fraction in response to the determined deviation.

[0142] Example 14: A system for determining the location of an atrial pacing lead for delivery in cardiac pacing therapy, comprising:

[0143] One or more pacing electrodes for delivering atrial pacing therapy in response to performing at least one of the following: positioning a single lead at a location adjacent to the Bachmann bundle, positioning a single lead in the right atrium, positioning a single lead in the left atrium, positioning a single lead in the atrial septum, and positioning a single lead in both the right and left atrium.

[0144] Multiple external electrodes are used to sense the electrical activity of the patient's tissues in response to delivered atrial pacing therapy; and

[0145] A computing device configured to: determine the distribution of bi-atrial excitation in response to sensed electrical activity; determine whether there is a desired change in bi-atrial asynchrony in response to the determined distribution of bi-atrial excitation; determine whether the lead placement endpoint has been reached; and determine the target site for delivering atrial pacing therapy in response to reaching the lead placement endpoint.

[0146] Example 15: The system of Example 14, wherein the computing device is configured to: compare the determined distribution of biatrial excitation with the distribution of biatrial excitation of the inherent rhythm; and in response to the comparison, determine whether there is a desired change in biatrial asynchrony.

[0147] Example 16: A system of any one of Examples 14-15, wherein the computing device is configured to: determine an increase in the amplitude of sensed electrical activity of a predetermined number of electrodes among a plurality of electrodes; determine a decrease in the amplitude of sensed electrical activity of a predetermined number of electrodes among a plurality of electrodes; generate electrical heterogeneity information of sensed electrical activity within a window extending between the determined increase in amplitude and the determined decrease in amplitude; and determine the distribution of biatrial excitation in response to the electrical heterogeneity information.

[0148] Example 17: A system of any one of Examples 14-16, wherein the computing device is configured to: determine a first set of excitation times corresponding to the posterior electrode group based on the sensed electrical activity within the window; determine a second set of excitation times corresponding to the anterior electrode group based on the sensed electrical activity within the window; determine a standard deviation of excitation times for the combination of the first set of excitation times and the second set of excitation times; and determine the biatrial asynchrony fraction in response to the determined standard deviation.

[0149] Example 18: The system of Example 17, wherein the computing device is configured to: compare the determined biatrial asynchrony fraction with the intrinsic rhythm biatrial asynchrony fraction; determine whether the biatrial asynchrony fraction corresponds to a predetermined decrease in the intrinsic rhythm biatrial asynchrony fraction; and determine, in response to the biatrial asynchrony fraction corresponding to the predetermined decrease, that the lead placement endpoint has been reached.

[0150] Example 19: A system of any one of Examples 17-18, wherein the computing device is configured to: compare a determined fraction of biatrial asynchrony with a fraction of biatrial asynchrony in the intrinsic rhythm; determine a change in biatrial asynchrony in response to the comparison; determine a desired change in biatrial asynchrony in response to a change in biatrial asynchrony determined for two or more of the following: positioning a single lead near the Bachmann bundle, positioning a single lead in the right atrium, positioning a single lead in the left atrium, positioning a single lead in the atrial septum, and positioning a single lead in both the right and left atrium; and determine that the lead placement endpoint has been reached in response to a comparison of two or more determined changes in biatrial asynchrony associated with determining a desired change in biatrial asynchrony.

[0151] Example 20: A system of any one of Examples 14-19, wherein the computing device is configured to: determine whether there is a desired change in atrial dyssynchrony for performing at least one of the following: positioning a single lead adjacent to the Bachmann bundle, positioning a single lead in the right atrium, positioning a single lead in the left atrium, positioning a single lead in the atrial septum, and positioning a single lead in both the right and left atrium; and determine whether there is a desired change in atrial dyssynchrony for performing another of the following: positioning a single lead adjacent to the Bachmann bundle. The single lead is positioned in the right atrium, in the left atrium, in the atrial septum, and in both the right and left atrium; and the lead placement endpoint is determined in response to a desired change in atrial synchrony for another of the following: positioning the single lead near the Bachmann bundle, positioning the single lead in the right atrium, positioning the single lead in the left atrium, positioning the single lead in the atrial septum, and positioning the single lead in both the right and left atrium.

[0152] Example 21: A system for evaluating atrial pacing therapy, comprising:

[0153] Multiple external electrodes are used to sense the electrical activity of the patient's tissues; and

[0154] A computing device, including a processing circuit system and coupled to an electrode device, is configured to:

[0155] Electrical activity was monitored using multiple external electrodes; and

[0156] Information on the electrical heterogeneity of the two atria is generated based on the monitored electrical activity.

[0157] Example 22: The system of Example 21, wherein, in order to generate information on the electrical heterogeneity of the two atrial organs based on the monitored electrical activity, the computing device is further configured to:

[0158] The activation times of multiple atria were determined based on the monitored electrical activity.

[0159] Example 23: The system described in any one of Examples 21-22, wherein, in order to generate information on the electrical heterogeneity of the two atrial organs based on the monitored electrical activity, the computing device is further configured to:

[0160] The increase in the amplitude of the sensed electrical activity of a predetermined number of electrodes out of a plurality of electrodes is determined;

[0161] Determine the reduction in the amplitude of the sensed electrical activity of a predetermined number of electrodes out of a plurality of electrodes;

[0162] Based on the sensed electrical activity within a window extending between a determined increase and a determined decrease in amplitude, atrial activation information is generated; and

[0163] Determine the electrical heterogeneity information of the two atria based on the atrial activation information.

[0164] Example 24: The system described in any one of Examples 21-23, wherein, in order to generate information on the electrical heterogeneity of the two atrial organs based on the monitored electrical activity, the computing device is further configured to:

[0165] Based on the monitored electrical activity, the first set of atrial activation times corresponding to the posterior electrode group was determined;

[0166] Based on the monitored electrical activity, the second set of atrial activation times corresponding to the anterior electrode group was determined; and

[0167] For the combination of the first group of excitation times and the second group of excitation times, the standard deviation of the excitation time is determined.

[0168] Example 25: The system described in any one of Examples 21-24, wherein, in order to generate bi-atrial electrical heterogeneity information based on monitored electrical activity, the computing device is further configured to: generate bi-atrial electrical heterogeneity information based on electrical activity monitored during pacing therapy delivered at multiple atrial pacing sites.

[0169] The system is further configured to determine the target atrial pacing site from multiple atrial pacing sites based on information about the electrical heterogeneity of the two atrial sites.

[0170] Example 26: The system of any one of Examples 21-25, wherein, in order to generate information on the electrical heterogeneity of the two atrial organs based on the monitored electrical activity, the computing device is further configured to:

[0171] Based on the electrical activity monitored during pacing therapy delivery, information on the biatrial electrical heterogeneity of pacing is generated; and

[0172] Based on electrical activity monitored during intrinsic cardiac excitation without the delivery of pacing therapy, intrinsic biatrial electrical heterogeneity information is generated, wherein the system is further configured to:

[0173] The information on the electrical heterogeneity of the pacing biatrial organs was compared with the information on the intrinsic electrical heterogeneity of the biatrial organs.

[0174] Example 27: The system of any one of Examples 21-26, wherein the computing device is configured to: determine changes in atrial asynchrony in response to the determined distribution of atrial excitation; and adjust the target site for delivering atrial pacing therapy in response to the determined changes in atrial asynchrony.

[0175] Example 28: The system of any one of Examples 25-27, wherein the computing device is configured to assign a score to each target atrial pacing site among a plurality of atrial pacing sites.

[0176] Example 29: The system of any one of Examples 25-28, wherein the computing device is configured to rank each target atrial pacing site based on each score assigned to each target atrial pacing site.

[0177] Example 30: The system of any one of Examples 21-29 further includes a graphical user interface coupled to a computing device, the graphical user interface being configured to display a ranking of each target atrial pacing site based on each score assigned to each target atrial pacing site.

[0178] Example 31: The system described in any one of Examples 28-30, wherein the score is associated with atrial asynchrony.

[0179] Example 32: The system described in any one of Examples 28-21, wherein the fraction is associated with atrial synchronization.

[0180] Example 33: The system of any one of Examples 9-12, wherein the computing device generates an optimal target atrial pacing site in response to the ranking of each target atrial pacing site.

[0181] Example 34: The system of any one of Examples 30-33, wherein the graphical user interface displays the optimal target atrial pacing site based on ranking.

[0182] Example 35: The system described in Example 34, wherein the optimal target atrial pacing site is graphically distinguished from other target atrial pacing sites.

[0183] Example 36: The system described in any one of Examples 35, wherein the optimal target atrial pacing site is graphically distinguished from other target atrial pacing sites by color.

[0184] Example 37: The system described in any one of Examples 35-36, wherein the optimal target atrial pacing site is graphically distinguished from other target atrial pacing sites by its vertical position on the graphical user interface.

[0185] Example 38: The system described in any one of Examples 5, wherein the optimal target atrial pacing site is graphically distinguished from other target atrial pacing sites by its horizontal position on the graphical user interface.

[0186] Example 39: The system described in any one of Examples 35, wherein the optimal target atrial pacing site is graphically distinguished from other target atrial pacing sites by delineation on the graphical user interface.

[0187] Example 40: The system described in any one of Examples 35, wherein the optimal target atrial pacing site is graphically distinguished from other target atrial pacing sites by an accent line on the graphical user interface.

Claims

1. A system for assessing biatrial dyssynchrony pacing therapy, comprising: an electrode apparatus comprising a plurality of external electrodes for sensing electrical activity of a patient's tissue, the plurality of external electrodes comprising a first electrode set and a second electrode set; and a computing apparatus comprising processing circuitry and coupled to the electrode apparatus, the computing apparatus configured to: monitor electrical activity corresponding to P-wave activation signals through both a left atrium and a right atrium of a heart using the plurality of external electrodes; and generate biatrial electrical heterogeneity information based on the monitored electrical activity, wherein to generate biatrial electrical heterogeneity information, the computing apparatus is further configured to: process P-waves based on the monitored electrical activity to determine a plurality of atrial activation times each corresponding to a single external electrode, the plurality of atrial activation times comprising a first set of atrial activation times corresponding to the first electrode set and a second set of atrial activation times corresponding to the second electrode set; and calculate a measure reflecting spatial electrical dyssynchrony of the biatrium based on a statistical measure applied to a combination of the first set of atrial activation times and the second set of atrial activation times. To generate biatrial electrical heterogeneity information, the computing apparatus is further configured to:

2. The system of claim 1, wherein, determine an increase in amplitude of sensed electrical activity of a predetermined number of electrodes of the plurality of external electrodes; determine a decrease in amplitude of sensed electrical activity of the predetermined number of electrodes of the plurality of external electrodes; generate electrical atrial activation information from sensed electrical activity within a window extending between the determined increase in amplitude and the determined decrease in amplitude; and determine the biatrial electrical heterogeneity information based on the electrical atrial activation information.

3. The system of any of claims 1-2, wherein: the first set of atrial activation times corresponds to a posterior electrode set; the second set of atrial activation times corresponds to an anterior electrode set; and the statistical measure is to determine an activation time standard deviation for the combination of the first set of atrial activation times and the second set of atrial activation times. To generate biatrial electrical heterogeneity information, the computing apparatus is further configured to:

4. The system of any one of claims 1-2, wherein, generate paced biatrial electrical heterogeneity information based on electrical activity monitored during delivery of pacing therapy at a plurality of atrial pacing sites, wherein the system is further configured to determine a target atrial pacing site from the plurality of atrial pacing sites based on the paced biatrial electrical heterogeneity information. To generate biatrial electrical heterogeneity information, the computing apparatus is further configured to:

5. The system of any one of claims 1-2, wherein, generate paced biatrial electrical heterogeneity information based on electrical activity monitored during delivery of atrial pacing therapy; and generate intrinsic biatrial electrical heterogeneity information based on electrical activity monitored during intrinsic heart activation without delivery of pacing therapy, wherein the system is further configured to: compare the paced biatrial electrical heterogeneity information to the intrinsic biatrial electrical heterogeneity information. The computing apparatus is configured to adjust a target site for delivery of the atrial pacing therapy in response to a determined change in spatial electrical dyssynchrony of the biatrium.

6. The system of claim 5, wherein, ​ 7. The system of claim 4, wherein, The computing device is configured to assign a score to each target atrial pacing site of the plurality of atrial pacing sites.

8. The system of claim 7, wherein, The computing device is configured to rank each target atrial pacing site based on each score assigned to each target atrial pacing site.

9. The system of claim 8, wherein, Further comprising a graphical user interface coupled to the computing device, the graphical user interface configured to display the ranking of each target atrial pacing site based on each score assigned to each target atrial pacing site.

10. The system of claim 7, wherein, The score is associated with atrial dyssynchrony.

11. The system of claim 7, wherein, The score is associated with atrial synchrony.

12. The system of claim 9, wherein, The computing device generates a best target atrial pacing site in response to the ranking of each target atrial pacing site.

13. The system of claim 12, wherein, The graphical user interface displays the best target atrial pacing site based on the ranked target atrial pacing site.

14. The system of claim 13, wherein, The best target atrial pacing site is graphically distinguished from other target atrial pacing sites.

15. The system of claim 14, wherein, The best target atrial pacing site is graphically distinguished from other target atrial pacing sites by color.

16. The system of claim 14, wherein, The best target atrial pacing site is graphically distinguished from other target atrial pacing sites by vertical position on the graphical user interface.

17. The system of claim 14, wherein, The best target atrial pacing site is graphically distinguished from other target atrial pacing sites by horizontal position on the graphical user interface.

18. The system of claim 14, wherein, The best target atrial pacing site is graphically distinguished from other target atrial pacing sites by encirclement on the graphical user interface.

19. The system of claim 14, wherein, The best target atrial pacing site is graphically distinguished from other target atrial pacing sites by a heavy line on the graphical user interface.

20. The system of claim 1, wherein, The computing device is further configured to derive an atrial activation map that is a surface isochronal map of a distribution of biatrial activation times.

21. The system of claim 1, wherein, The statistical measure applied to the combination of the first set of atrial activation times and the second set of atrial activation times is a statistical measure of heterogeneity and dispersion.

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