Devices and methods for anti-tachycardia pacing

Abstract

1. A method of anti-tachycardia pacing via an implantable cardiac device, comprising: positioning at least one electrode of the implantable cardiac device at a location within the heart; detecting a tachycardia episode; and delivering an anti-tachycardia pacing pulse via the at least one electrode, the anti-tachycardia pacing pulse having at least one of a duration between 5 and 10 milliseconds and an amplitude between 7.5 and 10 V.

Description

[Technical field]

[0001] Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 171,097, filed April 6, 2021, the contents of which are incorporated by reference in their entirety as if fully set forth herein. [Background technology]

[0002] The present invention, in some embodiments thereof, relates to anti-tachycardia (ATP) pacing, and more particularly, but not exclusively, to the delivery of ATP pulses having selected amplitudes and / or durations to effectively terminate arrhythmias.

[0003] Patent No. JP2016517771A discloses that "a substernal implantable cardioverter defibrillator (ICD) system and method for providing substernal electrical stimulation therapy to treat malignant tachyarrhythmias such as ventricular tachycardia (VT) and ventricular fibrillation (VF) are described. In one embodiment, the implantable cardioverter defibrillator (ICD) system includes an ICD implanted in a patient and an implantable medical electrical lead. The lead includes an elongated lead body having a proximal end and a distal portion, a connector at the proximal end of the lead body configured to couple to the ICD, and one or more electrodes along a distal portion of the elongated lead body. The distal portion of the elongated lead body of the lead is implanted substantially within the anterior mediastinum of the patient, and the ICD is configured to deliver electrical stimulation to the patient's heart using the one or more electrodes."

[0004] Patent No. US9031648B2 discloses that "According to one aspect, various methods and apparatus are used to treat a patient's cardiac condition and monitor cardiac activity. In one consistent approach, an electrode arrangement is attached to the right ventricle of the heart. The electrode arrangement is used to capture the myocardium and resynchronize the left and right ventricles by providing first and second signal components with opposite polarity on the respective electrodes. The electrode arrangement is connected to an implantable CRM device that provides atrial pacing / sensing, ventricular pacing / sensing capabilities and delivers defibrillation therapy from the right side of the heart. The CRM device captures ventricular contractions to treat conduction abnormalities in one or more ventricles." Summary of the Invention

[0005] According to some aspects of the embodiments there is provided a method of anti-tachycardia pacing via an implantable cardiac device, comprising: Positioning at least one electrode of an implantable cardiac device at an intracardiac location; Detecting a tachycardia episode; and delivering anti-tachycardia pacing pulses via at least one electrode, the anti-tachycardia pacing pulses having at least one of a duration between 5-10 milliseconds and an amplitude between 5-10 V; A method is provided that includes:

[0006] In some embodiments, the location within the heart is one of the interventricular septum, the left ventricular wall, or the right ventricular wall.

[0007] In some embodiments, the method includes placing at least two electrodes at at least two different intracardiac locations.

[0008] In some embodiments, the method includes placing at least two electrodes at two different locations within the right ventricle.

[0009] In some embodiments, the method includes placing at least two electrodes at two different locations along the ventricular septum.

[0010] In some embodiments, the method includes placing at least one electrode in the right ventricle and at least one electrode in the left ventricle.

[0011] In some embodiments, the method further includes delivering a defibrillation pulse if the tachycardia episode persists after delivery of the anti-tachycardia pacing pulse.

[0012] In some embodiments, the detecting is performed by measuring the RR interval via at least one electrode of the implantable cardiac device.

[0013] In some embodiments, the anti-tachycardia pulse is a biphasic pulse.

[0014] In some embodiments, the delivering includes delivering synchronized anti-tachycardia pacing pulses via at least two electrodes.

[0015] In some embodiments, the delivering includes delivering the anti-tachycardia pacing pulses simultaneously via at least two electrodes.

[0016] In some embodiments, the delivering includes delivering the anti-tachycardia pacing pulse with a time delay such that a pulse applied via one of the two electrodes is delivered with a predetermined time delay from a pulse applied via the other of the two electrodes.

[0017] In some embodiments, the predetermined time delay is selected according to a time difference between R-wave occurrences measured by at least two electrodes at at least two different cardiac locations during normal cardiac function.

[0018] In some embodiments, the detecting includes measuring a heart rate between 180 and 250 BPM.

[0019] According to an aspect of some embodiments, at least one lead electrode configured to contact intracardiac tissue; a housing containing circuitry for controlling and activating at least one lead electrode; a pulse generator configured to generate anti-tachycardia pacing pulses to be delivered by at least one lead electrode, the anti-tachycardia pacing pulses having at least one of a duration between 5-10 milliseconds and an amplitude between 5-10 V; An implantable cardiac device is provided comprising:

[0020] In some embodiments, the circuitry comprises a memory that stores a plurality of anti-tachycardia pacing pulse sequences and a controller configured to execute delivery of a selected anti-tachycardia pacing pulse sequence.

[0021] In some embodiments the cardiac device comprises: delivering a cardiac contractility modulation stimulus having a duration between 5-10 milliseconds and an amplitude between 5-10 V during normal sinus rhythm; delivering a defibrillation shock; The method is further configured for one or more of:

[0022] In some embodiments, the cardiac device comprises at least two lead electrodes configured to contact intracardiac tissue.

[0023] In some embodiments, the endocardial tissue is one of the interventricular septum, the left ventricular wall, or the right ventricular wall.

[0024] In some embodiments, the device comprises at least two lead electrodes configured for placement at at least two different intracardiac locations.

[0025] In some embodiments, the at least two distinct intracardiac locations are within the right ventricle.

[0026] In some embodiments, the at least two distinct intracardiac locations are along the interventricular septum.

[0027] In some embodiments, the at least two different intracardiac locations include the right ventricle and the left ventricle.

[0028] In some embodiments, the circuitry is configured to detect a tachycardia episode, and the pulse generator is configured to deliver a defibrillation pulse if the detected tachycardia episode continues after delivery of the anti-tachycardia pacing pulse.

[0029] In some embodiments, the circuitry is configured to detect tachycardia episodes by measuring the RR interval via at least one lead electrode.

[0030] In some embodiments, the circuitry is configured to detect tachycardia episodes upon measuring a heart rate between 180 and 250 BPM.

[0031] In some embodiments, the anti-tachycardia pacing pulses are biphasic pulses.

[0032] In some embodiments, the pulse generator is configured to generate synchronized anti-tachycardia pacing pulses to be delivered via the at least two lead electrodes.

[0033] In some embodiments, the pulse generator is configured to simultaneously generate anti-tachycardia pacing pulses.

[0034] In some embodiments, the pulse generator is configured to generate synchronized anti-tachycardia pacing pulses with a time delay between them such that a pulse applied via one of the two lead electrodes is delivered at a predetermined time delay from a pulse applied via the other of the at least two lead electrodes.

[0035] In some embodiments, the predetermined time delay is selected according to a time difference between R-wave occurrences measured via at least two electrodes at at least two different cardiac locations during normal cardiac function.

[0036] In some embodiments, the pulse generator is configured to generate anti-tachycardia pacing pulses having different durations selected from between 5 and 10 milliseconds.

[0037] According to some aspects of the embodiments there is provided a method of anti-tachycardia pacing via an implantable cardiac device comprising: Detecting a tachycardia episode; and delivering a pulse sequence combining anti-tachycardia pacing pulses having different durations; A method is provided that includes:

[0038] In some embodiments, the pulse duration is between 0.1 and 10 milliseconds.

[0039] In some embodiments, the anti-tachycardia pacing pulses include wide pacing pulses and narrow pacing pulses, the wide pacing pulses having a duration between 2-10 milliseconds and the narrow pacing pulses having a duration between 0.1-5 milliseconds.

[0040] In some embodiments, the delivering includes delivering a plurality of narrow pacing pulses followed by a plurality of wide pacing pulses.

[0041] In some embodiments, the delivering includes delivering a sequence including pairs of pulses, where in each pair a narrow pacing pulse is followed by a wide pacing pulse, and where the narrow pacing pulse and the wide pacing pulse are delivered within the same cardiac cycle.

[0042] In some embodiments, the wide pacing pulse is delivered during the refractory period caused by the narrow pulse.

[0043] In some embodiments, the delivering includes delivering a sequence of pacing pulses of gradually increasing duration.

[0044] In some embodiments, each pulse is at least 10% longer than the previous pulse.

[0045] In some embodiments, the delivering includes delivering a sequence of pacing pulses of gradually decreasing duration.

[0046] In some embodiments, each pulse is at least 10% shorter than the previous pulse.

[0047] According to some aspects of the embodiments there is provided a method of anti-tachycardia pacing via an implantable cardiac device comprising: Detecting a tachycardia episode; and delivering anti-tachycardia pacing pulses via at least two electrodes positioned in contact with tissue at at least two different intracardiac locations; A method is provided that includes:

[0048] In some embodiments, the method further comprises measuring the time difference between R-wave occurrences at at least two different intracardiac locations during normal cardiac function.

[0049] In some embodiments, the time interval between pacing pulses delivered to two different intracardiac locations is set according to the measured time difference.

[0050] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used to practice or test embodiments of the present invention, exemplary methods and / or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

[0051] Implementation of the method and / or system of the present invention may involve performing or completing selected tasks manually, automatically, or a combination thereof. Further, depending on the actual instrumentation and implementation of the method and / or system of the present invention, some selected tasks may be implemented using an operating system, by hardware, software, or firmware, or a combination thereof.

[0052] For example, hardware for performing selected tasks according to embodiments of the present invention may be implemented as a chip or circuit. As software, selected tasks according to embodiments of the present invention may be implemented as a number of software instructions executed by a computer using any suitable operating system. In an exemplary embodiment of the present invention, one or more tasks according to exemplary embodiments of the methods and / or systems described herein are performed by a data processor, such as a computing platform for executing a number of instructions. Optionally, the data processor includes volatile memory for storing instructions and / or data, and / or non-volatile storage, e.g., a magnetic hard disk and / or removable media, for storing instructions and / or data. Optionally, a network connection is also provided. A display and / or a user input device, such as a keyboard or mouse, are also optionally provided.

[0053] Some embodiments of the present invention are herein described, by way of example only, with reference to the accompanying drawings, in which: Reference will now be made specifically to the drawings in detail, stressing that the particulars shown are for the purpose of illustrating and discussing embodiments of the present invention by way of example, and in this regard the description made with the drawings will make apparent to those skilled in the art how embodiments of the present invention may be practiced. [Brief description of the drawings]

[0054] [Figure 1] 1A-C are schematic diagrams illustrating three exemplary configurations of an implantable cardiac device, according to some embodiments. [Diagram 2] FIG. 1 is a block diagram of components of an implantable cardiac device, according to some embodiments. [Figure 3A] FIG. 1 illustrates anti-tachycardia pacing, according to some embodiments. [Figure 3B] 13A-13C are schematic illustrations of potential effects of anti-tachycardia pacing pulses on cardiac tissue, according to some embodiments. [Figure 3C] 13A-13C are schematic diagrams illustrating the extent of effect of an ATP pulse on cardiac tissue in two example ventricular tachycardia conditions, according to some embodiments. [Figure 3D] 13A-13C are schematic diagrams illustrating the extent of effect of an ATP pulse on cardiac tissue in two example ventricular tachycardia conditions, according to some embodiments. [Figure 4] 1 is a flowchart of a general method for delivering enhanced pacing pulses via one or more intracardiac electrodes to treat tachycardia, according to some embodiments. [Diagram 5] FIG. 1 illustrates anti-tachycardia pacing by delivering synchronous pacing pulses to at least two different cardiac locations, according to some embodiments. [Figure 6] 1 is a flowchart of a method for adjusting the timing of anti-tachycardia pacing delivered to at least two different cardiac locations according to a measured time interval between R-wave occurrences at the two locations, according to some embodiments. [Figure 7] FIG. 1 illustrates anti-tachycardia pacing by delivering pacing pulses to at least two different cardiac locations that are timed according to the time interval between R-wave occurrences at the two locations. [Figure 8] 1 is a flowchart of a method for delivering a pulse sequence combining wide and narrow pacing pulses to treat tachycardia, in accordance with some embodiments. [Figure 9] FIG. 1 illustrates anti-tachycardia pacing with a first exemplary combination of wide and narrow pacing pulses, in accordance with some embodiments. [Figure 10] FIG. 13 illustrates anti-tachycardia pacing with a second exemplary combination of wide and narrow pacing pulses, in accordance with some embodiments. [Figure 11] FIG. 13 illustrates anti-tachycardia pacing with a third exemplary combination of wide and narrow pacing pulses, in accordance with some embodiments. [Figure 12] FIG. 13 illustrates anti-tachycardia pacing with a fourth exemplary combination of wide and narrow pacing pulses, in accordance with some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0055] The present invention, in some embodiments thereof, relates to anti-tachycardia (ATP) pacing, and more particularly, but not exclusively, to the delivery of ATP pulses having selected amplitudes and / or durations to effectively terminate arrhythmias.

[0056] A broad aspect of some embodiments relates to anti-tachycardia pacing in which the pacing pulses delivered into the heart are relatively high-power and / or long-duration. In some embodiments, the ATP pulse parameters (such as pulse amplitude, pulse duration, application frequency, application timing, number of pulses in a sequence, and / or other parameters) are selected to interrupt the tachyarrhythmia and override the natural rhythm. In some embodiments, the ATP pulse parameters are selected to affect a relatively large area of ​​cardiac tissue, for example, compared to the tissue area affected by a weaker and / or shorter pulse. Optionally, the ATP pulses are set to capture a larger number of cardiomyocytes, for example, compared to the number of cardiomyocytes captured by a weaker and / or shorter pulse.

[0057] In some embodiments, the ATP pulses have amplitudes between, for example, 7-10V, 5-10V, 3-8V, or intermediate amplitudes, higher or lower amplitudes, and / or durations between 5-10 ms, 2-10 ms, 7-12 ms, or intermediate durations, longer or shorter durations, respectively. In some embodiments, the upper threshold of the pulse amplitude is selected low enough to still allow delivery of the signal to the cardiac tissue itself (endocardial tissue) without risking damage to the tissue that may be caused by too high a voltage. Examples of upper threshold of the ATP pulse amplitude may include 10V, 9V, 11V, or intermediate voltages, higher or lower voltages.

[0058] In some embodiments, the ATP pulse is a biphasic pulse. In some embodiments, multiple ATP pulses are delivered consecutively, for example with a time interval between subsequent pulses of between 150 ms and 400 ms.

[0059] In some embodiments, the ATP pulses are delivered via multiple lead electrodes (e.g., 1, 2, 3, 4, 5, 6, 8 electrodes, or intermediate, greater or lesser number of electrodes) in contact with endocardial tissue. Optionally, the electrodes contact the inner wall of the heart, e.g., are attached in conductive contact with the myocardial tissue.

[0060] Potential benefits of anti-tachycardia pacing delivered to the heart using, for example, parameters as described herein, may include interrupting the arrhythmia with faster and / or fewer pulses (e.g., compared to using weaker and / or shorter pulses). Another potential benefit of stronger and / or longer pulses may include improved conduction of the excitatory signal, for example, because a longer and / or stronger signal may be more effective at trapping myocardial cells adjacent to damaged tissue areas where signal conduction may be slower or the signal would otherwise travel through an alternative conduction pathway.

[0061] Aspects of some embodiments relate to delivering ATP pulses to at least two different intracardiac locations. In some embodiments, the ATP pulses are delivered via two or more electrodes of an implantable device, with each electrode contacting a different cardiac tissue site. The electrodes are, for example, placed in two locations in the right ventricle, placed in two locations along the ventricular septum, one electrode placed in the septum and one electrode placed in the right or left ventricle, one electrode placed in the right ventricle and one electrode placed in the left ventricle, and / or other locations.

[0062] In some embodiments, the ATP pulse sequence delivered via at least two electrodes is synchronized. Alternatively, the ATP pulse sequence is delivered with a predefined delay between the pulses delivered to each location. In some embodiments, the delay is adjusted according to the time difference between the occurrence of R waves at the two locations, optionally measured by the two electrodes.

[0063] Aspects of some embodiments relate to ATP pulse sequences that combine pulses of different durations.

[0064] In some embodiments, the pulse sequence combines wide pacing pulses (e.g., having a duration between 5-10 milliseconds) with narrow pacing pulses (e.g., having a duration between 0.1-2 milliseconds). In some embodiments, multiple narrow pulses are followed by multiple wide pulses. In some embodiments, pairs of wide and narrow pulses are delivered, each pair including, for example, a narrow pulse followed by a wide pulse, optionally delivered during a refractory period caused by the narrow pulse.

[0065] In some embodiments, the duration of the pulses in the sequence increases gradually, e.g., each pulse is at least 10%, at least 20%, at least 40%, or an intermediate, greater or lesser percentage, longer than the previous pulse. Alternatively, in some embodiments, the duration of the pulses in the sequence decreases gradually, e.g., each pulse is at least 10%, at least 20%, at least 40%, or an intermediate, greater or lesser percentage, shorter than the previous pulse.

[0066] Aspects of some embodiments relate to an implantable cardiac device configured to deliver ATP pulses having parameters (e.g., amplitude, duration, frequency), such as those described herein. In some embodiments, the device is provided with a power supply (e.g., a battery) and circuitry suitable for generating relatively strong ATP pulses.

[0067] In some embodiments, the device is configured to detect heart attacks and / or cardiac cycle characteristics, for example, via one or more lead electrodes of the device (which also deliver signals) and / or one or more sensors of the device.

[0068] In some embodiments, a tachycardia episode is detected (e.g., by electrodes of the device) when the measured or estimated heart rate exceeds 180 BPM, exceeds 200 BPM, exceeds 230 BPM, or exceeds an intermediate, higher or lower threshold, and in response, an ATP pulse is delivered to treat the tachycardia episode.

[0069] In some embodiments, the device is implanted outside the heart, for example in the subclavian region, and one or more leads of the device extend into the heart where the electrode(s) of the lead are attached in contact with cardiac tissue. Additionally or alternatively, in some embodiments, one or more leads of the device are positioned outside the heart, for example with electrodes placed in the pericardial space.

[0070] In some embodiments, the device is a multi-function device configured to deliver multiple signal types. In some embodiments, the device is configured to generate and deliver one or more of ATP pulses, biventricular pacing pulses, cardiac contractility stimulation, and defibrillation shocks. The different signal types may differ from each other in amplitude, duration, timing of the signal relative to the cardiac cycle, frequency, number of stimulations required, etc.

[0071] Before describing at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of components and / or methods set forth in the following description and / or illustrated in the drawings and / or examples. The invention is capable of other embodiments or of being practiced or carried out in various ways.

[0072] Referring now to the drawings, FIGS. 1A-1C are schematic diagrams illustrating three exemplary configurations of an implantable cardiac device, according to some embodiments.

[0073] 1A, in some embodiments, an implantable device 101 comprises a pulse generator 103. In some embodiments, the pulse generator 103 comprises a housing 109 that encases, for example, a power supply means (e.g., a battery), control circuitry (e.g., a controller) configured to generate timed electrical pulses, sensing circuitry, communication circuitry, memory means, and / or other operational modules.

[0074] In some embodiments, one or more stimulation leads, such as 105, 107, are operably connected to the pulse generator and extend externally from the housing. In some embodiments, the leads are connected to the device housing via multiple ports (not shown) in the housing. In some embodiments, control of activation of the one or more leads is via switch circuitry, for example, switch circuitry of the device controller.

[0075] In some embodiments, the lead comprises one or more electrical wires surrounded by an outer insulating layer. In some embodiments, the lead is composed of two wires with different polarities. In some embodiments, the lead wire is wound into a coil.

[0076] In some embodiments, the pulse generator 103 is implanted outside the heart, for example in the subclavian region. Optionally, implantation is performed by a minimally invasive procedure.

[0077] In some embodiments, the housing of the pulse generator 103 is implanted subcutaneously, for example near the left chest.

[0078] In some embodiments, leads 105 and 107 extend from the pulse generator 103, with at least distal segments of the leads implanted within the heart 111. In some embodiments, as shown, both leads pass through the right atrium 113 into the right ventricle 114 and contact the ventricular septum 115 at their distal ends. In some embodiments, each lead contacts the septum at a different location.

[0079] In some embodiments, each lead terminates in a tip electrode (see 117 on lead 107, 119 on lead 105). The tip electrode may be configured as a contact electrode, a screw-in electrode, a suture electrode, a free-floating electrode, and / or other type.

[0080] In some embodiments, one or both of the leads includes a ring electrode (see 121 on lead 107, 123 on lead 105) that is placed along the lead proximal to the tip electrode.

[0081] In some embodiments, the ring electrode and / or the tip electrode are implanted in the right ventricle or right atrium of the heart.

[0082] In some embodiments, the tip electrode is threaded so that it is screwed into tissue, or the tip electrode is simply placed in contact with tissue.

[0083] In some embodiments, one or both of the leads includes a defibrillation coil (see 125 on lead 107). Optionally, the coil 125 is placed along the lead proximal to the tip electrode and / or proximal to the ring electrode.

[0084] In some embodiments, the coil is implanted in the right ventricle, right atrium, or vena cava.

[0085] In some embodiments, the tip electrode of the lead is fixed to the tissue of the interventricular septum, which may improve tissue contact and reduce unwanted lead movement and / or lead dislodgement.

[0086] 1B, in some embodiments, the implantable device comprises a single lead 151 including multiple spaced apart electrodes 152 (e.g., 2, 3, 4, 5, 6, 8, or an intermediate, greater or lesser number of electrodes). Optionally, the lead 151 is introduced into the left ventricle 153, for example through the coronary sinus. Additionally or alternatively, a single lead with multiple electrodes is introduced into the right ventricle.

[0087] Referring to FIG. 1C, in some embodiments, the implantable device comprises multiple leads including, for example, right ventricular leads 161, 163, a left ventricular lead 165, and optionally, a lead 167 introduced into the right atrium.

[0088] It should be noted that one or more leads may be placed in other locations, thereby targeting a different circle of effect and / or different tissue.

[0089] In some embodiments, a lead is implanted outside the heart and one or more additional leads are implanted inside the heart.

[0090] In some embodiments, one or more lead electrodes are used as sensors, for example to measure the R wave amplitude and / or the RR interval of the cardiac cycle.

[0091] FIG. 2 is a block diagram of components of an implantable cardiac device, according to some embodiments.

[0092] In some embodiments, device 200 includes one or more leads 216 (optionally two leads) that are optionally coupled to device 200 (such as a device housing), e.g., via one or more respective connectors (not shown).

[0093] In some embodiments, the pulse generator 204 is configured to generate a signal, optionally in response to a command from the controller 202. In some embodiments, the pulse generator includes a power supply circuit including, for example, one or more capacitors. In some embodiments, the pulse generator comprises or is operably connected to a power source, such as a battery.

[0094] In some embodiments, a ventricular detector 206 is provided and used to detect atypical ventricular activation, such as ventricular tachycardia.

[0095] In some embodiments, an atrial detector 208 is provided and used to detect atypical atrial activation, such as atrial fibrillation, atrial flutter, and the like.

[0096] In some embodiments, the sensor input 214 can receive data from one or more sensors, e.g., electrical sensors, or other sensors such as flow, pressure, and / or acceleration sensors. Optionally, in addition to or instead of delivering a signal to the tissue, one or more device electrodes are used as sensors. In some embodiments, data acquired by the sensors is processed (e.g., by the controller 202 and / or by the detectors 206, 208) and optionally used as input to a decision-making process in the device 200. For example, in some embodiments, ATP pulse signal parameters (e.g., amplitude, width, interval between pulses, duration of the pulse train, and / or other parameters) are selected in response to data acquired by the device sensors (optionally device electrodes).

[0097] In some embodiments, the controller 202 is configured to execute one or more logics to determine signal parameters such as, for example, the timing of applying a signal, the amplitude of the signal, the duration of the signal, and the like.

[0098] In some embodiments, the controller commands the application of pulses in response to data received from one or more sensors, for example, upon detecting an elevated heart rate (optionally above a set threshold), the controller commands the application of pacing pulses.

[0099] In some embodiments, the controller commands the application of pulses according to a treatment plan. Optionally, the controller effects modifications of the plan, for example, to compensate for real-time deviations from the treatment plan (e.g., skipped stimulation). In some embodiments, the controller generates commands to energize one or more leads of the device with signals. Optionally, the commands are generated according to the treatment plan. In some embodiments, in response to commands generated by the controller, electrical current is conducted through one or more leads, optionally to tissue that the one or more leads contact.

[0100] In some embodiments, memory 218 is optionally provided to store, for example, logic, past effects, treatment plans, adverse events, and / or pulse parameters.

[0101] In some embodiments, the controller and / or memory are programmed with one or more treatment plans (optionally set for a particular patient) and / or one or more fallback treatment plans.

[0102] In some embodiments, the controller references a look-up table, database, etc. that associates a particular cardiac event (eg, a sensed tachycardia episode) with instructions for treating that event.

[0103] In some embodiments, a logger 210 is optionally provided to store device 200 and / or patient activity. Such logging and / or programming can use a communications module 212 to transmit data from the device 200, for example to a programmer, physician, hospital or clinic database. In some embodiments, the communications module is configured to receive data, for example pulse parameters, to be programmed into the device.

[0104] FIG. 3A is a diagram illustrating anti-tachycardia pacing, according to some embodiments.

[0105] In some embodiments, an implantable cardiac device, such as those described herein, is configured to generate and deliver anti-tachycardia pacing pulses 301. In some embodiments, the pulses are delivered as a biphasic waveform, as shown. In some embodiments, a pulse train is delivered. In some embodiments, the pulse train comprises a rectangular or square waveform.

[0106] In some embodiments, the width (or duration) 303 of the single pacing pulse 301 is between 5 and 10 ms, between 3 and 7 ms, between 5 and 15 ms, or an intermediate width, longer or shorter width. Optionally, the pulse width is greater than 2 ms, 4 ms, 6 ms, or an intermediate width, longer or shorter width.

[0107] In some embodiments, the amplitude 305 of the single pacing pulse 301 is 7-10 volts, 5-8 volts, 3-12 volts, or an intermediate, greater or lesser amplitude. Optionally, the pulse amplitude is greater than 7 volts, greater than 8 volts, greater than 9 volts, or an intermediate, greater or lesser amplitude.

[0108] In some embodiments, the time interval 307 between successive pulses (i.e., between the onset of successive pulses) is between 200 and 500 milliseconds, e.g., 250 milliseconds, 300 milliseconds, 400 milliseconds, or an intermediate interval, shorter or longer.

[0109] In some embodiments, the value of pulse width x pulse amplitude is greater than 15 volts*ms, 25 volts*ms, 50 volts*ms, 70 volts*ms, or any intermediate, greater or lesser value. Optionally, the pulse width x pulse amplitude is between 35-100 volts*ms, between 50-75 volts*ms, between 20-60 volts*ms, or any intermediate, greater or lesser value.

[0110] In some embodiments, a cardiac device configured to apply anti-tachycardia pacing pulses, for example having an amplitude between 7.5V and 10V, is provided with suitable power supply means and circuitry to generate pulses of this relatively high voltage.

[0111] FIG. 3B illustrates generally the potential effects of anti-tachycardia pacing pulses on cardiac tissue, according to some embodiments.

[0112] In some embodiments, the ATP pulses are delivered via at least one electrode 355 in contact with tissue located inside the heart. In this example, the electrode 355 is placed in contact with the ventricular septum. Additional locations within the heart where electrodes may be placed include the right ventricular wall, the left ventricular wall, and the cardiac septum. In some embodiments, one or more electrodes are placed in the right atrium and / or the left atrium.

[0113] In some embodiments, pacing pulses are delivered to treat ventricular tachycardia by providing stimulation with suitable parameters to interrupt the arrhythmia and restore normal sinus rhythm, hi some embodiments, the pacing pulses are timed to open a reentry circuit, for example, by pacing at a rate higher than the heart rate of the tachyarrhythmia to "take over" the cycle.

[0114] In some embodiments, the ATP pulses are delivered for a period of time short enough to reduce the risk of or prevent acceleration of an existing arrhythmia.

[0115] In some embodiments, the delivered ATP pulses are broader (longer) and / or stronger (larger amplitude) than typical ATP pulses known in the art, e.g., pulses each having a width between 0.5-2 milliseconds.

[0116] For example, the delivered pulse is at least 50%, at least 80%, at least 100%, at least 120%, or intermediate, greater or lesser percentages longer than the length (duration) of a commonly used ATP pulse. Potential advantages of an enhanced (wider and / or more powerful) ATP pulse may include, for example, affecting a larger area of ​​cardiac tissue (schematically illustrated by 351) compared to the tissue area (schematically illustrated by 353) affected by a standard (known in the art) ATP pulse. Optionally, the enhanced pulse affects more cardiac myocytes, for example, signaling contraction of cardiac myocytes. This may allow for faster and / or smaller amounts of ATP pulses to be delivered to interrupt arrhythmias, for example, compared to standard ATP.

[0117] Another potential advantage of stronger and / or longer pulses may include improved conduction of the excitatory signal, for example, because a longer and / or stronger signal may be more effective at trapping myocardial cells adjacent to areas of damaged tissue where conduction of the signal may be slower or the signal would take an alternative conduction pathway.

[0118] In some embodiments, the stronger and / or longer range of effect of the ATP pulse on the tissue affects Purkinje fibers that run along the left and right ventricular walls. Direct excitation of Purkinje fibers by the ATP pulse may improve conduction and activation of ventricular wall tissue.

[0119] 3C-3D show schematic diagrams illustrating the range of effect of an ATP pulse on cardiac tissue in two example ventricular tachycardia conditions, according to some embodiments.

[0120] 3C illustrates, in a schematic manner, the effect of an ATP pulse delivered to two intracardiac locations, for example, via two electrodes 371, 373. In some embodiments, as shown in this example, the electrodes are placed in contact with tissue of the interventricular septum 375.

[0121] In some cases, ventricular tachycardia is accompanied by reentry cycles that are generated and / or caused by tissue with impaired conduction, such as damaged or scarred tissue 377. In such cases, action potentials can travel around the damaged or scarred tissue, causing new (or recurrent) activation of cells, potentially resulting in tachycardia.

[0122] In some embodiments, ATP pulses are applied via at least two electrodes to treat tachycardia. Potential advantages of applying ATP pulses to two additional locations within the heart as shown in the figures may include, for example, more effective suppression of reentry cycles, optionally in a synchronized manner, as action potentials generated by the applied ATP pulses travel from two electrode locations, optionally simultaneously affecting a larger portion of tissue, thereby "taking over" the reentry cycle.

[0123] 3D illustrates, in a schematic manner, the effect of an ATP pulse delivered, for example, via two electrodes 381, 383 to two intracardiac locations. In some embodiments, as shown in this example, the electrodes are placed in contact with tissue of the interventricular septum 385. In some cases, ventricular tachycardia results from a localized arrhythmogenic site 387 that acts as a pacemaker to activate contractions at a rapid rate.

[0124] In some embodiments, ATP pulses are applied via at least two electrodes to treat tachycardia. As shown, potential benefits of applying ATP pulses to two additional locations within the heart may include suppressing focal arrhythmogenic sites, optionally in a synchronized manner, and "capturing" additional tissue regions in other parts of the heart, thereby potentially reducing the influence of focal arrhythmogenic sites.

[0125] FIG. 4 is a flowchart of a general method for delivering enhanced pacing pulses via one or more intracardiac electrodes to treat tachycardia, according to some embodiments.

[0126] In some embodiments, a decision is made (e.g., by a physician) to treat a patient (401). In some embodiments, the patient selected for treatment is a patient suffering from a heart rhythm disorder, e.g., tachycardia. In some embodiments, a patient suffering from a cardiac condition, such as heart failure, congestive heart failure, and / or similar conditions, is selected for treatment.

[0127] In some embodiments, a cardiac device configured to pace the heart, for example with ATP, is implanted in the patient 403. In some embodiments, the device comprises a pulse generator, optionally implanted outside the heart, for example in the subclavian region, and one or more leads for delivering signals to the heart.

[0128] In some embodiments, a ventricular tachycardia episode is detected (405). In some embodiments, ventricular tachycardia is detected when the heart rate exceeds a threshold, e.g., above 160 BPM, above 187 BPM, above 200 BPM, above 230 BPM, or above an intermediate rate, higher or lower rate. In some embodiments, a heart rate between 187 and 250 BPM indicates a tachycardia. In some embodiments, ventricular tachycardia is detected when the cardiac cycle length (heart beats) is between 240 and 320 milliseconds, between 260 and 300 milliseconds, between 220 and 320 milliseconds, or an intermediate range, higher or lower range.

[0129] In some embodiments, the heart rate and / or cardiac cycle length are measured by an implanted device, for example by electrodes of the device. In some embodiments, the heart rate and / or cardiac cycle length are calculated according to the RR intervals measured by the electrodes.

[0130] In some embodiments, the device is programmed to deliver an ATP pulse via one or more device electrodes in contact with a location within the heart, e.g., in contact with myocardial tissue, upon detection of a tachycardia episode (407).

[0131] In some embodiments, two electrodes contact two different intracardiac locations. In some embodiments, the electrodes contact at least two different locations along the ventricular septum. In some embodiments, the electrodes contact at least two different locations of the left ventricular wall. In some embodiments, the electrodes contact at least two different locations of the right ventricular wall. In some embodiments, one electrode contacts the left ventricular wall and the other electrode contacts the right ventricular wall. In some embodiments, the electrodes contact at least two different locations on the right side of the ventricular septum.

[0132] Potential advantages of delivering ATP pulses to at least two tissue locations may include an increased likelihood of interrupting reentry of the tachycardia. Optionally, the tachycardia is interrupted as a result of simultaneously affecting tissue regions at two locations where the electrodes contact. Optionally, the tachycardia is interrupted as a result of applying pacing pulses to at least two locations in an order (e.g., with a time interval) determined according to the natural propagation direction and / or velocity of the action potential.

[0133] In some cases, the reentry focus is located at or near scarred or damaged myocardial tissue. Optionally, one or more electrodes of the cardiac device may be positioned adjacent to or at the suspected focus of reentry.

[0134] In some embodiments, the ATP pulse is delivered using parameters such as those described above in FIG. 3A.

[0135] In some embodiments, a combination of pulses is delivered, with some pulses having a higher amplitude and / or longer duration than others. Optionally, the pulses are delivered in pairs, e.g., each pair is delivered within a single cardiac cycle. In one example, a short pulse is provided first, then a longer pulse is delivered, e.g., during the refractory period caused by the first pulse.

[0136] In some embodiments, the duration and / or amplitude of the pulses is gradually increased.

[0137] In some embodiments, if the tachycardia continues despite the application of the ATP pulse, a more powerful defibrillation pulse is delivered (409). In some embodiments, the defibrillation pulse(s) is delivered after a set number of cardiac cycles after the ATP pulse was applied, e.g., after 2, 4, 6, 10, or an intermediate, greater or lesser number of cycles. In some embodiments, the defibrillation pulse energy is between 10-100 Joules, e.g., 30 Joules, 50 Joules, 25 Joules, or intermediate, higher or lower energy.

[0138] Potential advantages of delivering ATP pulses to target ventricular tachycardia, as opposed to directly applying defibrillation pulses, may include reducing or preventing damage to cardiac tissue that can occur as a result of the strong electrical shock delivered by the defibrillation pulse.

[0139] For example, potential benefits of ATP pulses having the amplitudes described herein (e.g., 7-10 V) may include improving the ability of the stimulation to take over tachycardia rhythms, potentially reducing the need to deliver defibrillation pulses.

[0140] The following is an example of an operation scheme of an implantable cardiac device configured to deliver multiple cardiac stimulation signals, including but not limited to pacing signals (e.g., ventricular pacing signals), defibrillation signals, contractility modulation signals, and / or anti-tachycardia pacing signals. In an example, the implantable device is configured to generate and deliver all of the following types of stimulation: biventricular pacing, ATP pulses, contractility modulation signals, and defibrillation shocks.

[0141] Exemplary Operational Schemes for Implantable Devices Configured for Combined CRT, CCM, ICD, and / or ATP Therapy In some embodiments, if the BPM is within the normal range, the device delivers biventricular pacing (CRT cardiac resynchronization therapy).

[0142] Optionally, during a portion of the time and / or at a predetermined timing, the device delivers a cardiac contractility modulation (CCM) stimulus, such as a non-excitatory stimulus. In some embodiments, the CCM stimulus is delivered during normal sinus rhythm. In some embodiments, the CCM stimulus has an amplitude between 7-10V and a duration between 4-6 ms. The cardiac contractility modulation stimulus is optionally delivered during a ventricular refractory period, for example, between 0.5-5 ms after CRT pacing. In some embodiments, the CCM stimulus is delivered via one or more leads that contact the ventricular septum.

[0143] In some embodiments, the cardiac contractility modulation stimulus is selected to increase the contractility of ventricular tissue, e.g., the left ventricle, the right ventricle, and / or the ventricular septum, when the electric field of the signal stimulates such ventricle. In some embodiments, the contractility modulation is provided by the phosphorylation of phospholamban caused by the signal. In some embodiments of the present invention, the contractility modulation is caused by the change in protein transcription and / or mRNA production caused by the signal, optionally in the form of reversal of the fetal gene program.

[0144] In some embodiments, if a BPM above a certain threshold is detected by the device, e.g., BPM>180, BPM>200, BPM>160, or a BPM above an intermediate, higher or lower threshold, an ATP pulse signal having parameters, e.g., as described herein, is delivered by the device.

[0145] In some embodiments, a defibrillation shock is delivered by the device if the BPM continues to increase for a certain period of time (e.g., a predefined period of time as programmed into the device) and / or if the initially detected BPM is higher than another threshold, e.g., BPM>250, BPM>300, BPM>280, BPM>320, or higher than an intermediate, higher or lower threshold.

[0146] In some embodiments, the decisions about what type of signal to apply, what signal parameters to select, and when to time the signals are made by a device controller in response to measurements obtained, for example, by one or more electrodes on the device, and / or one or more sensors on the device, and / or one or more sensors external to the device.

[0147] FIG. 5 is a diagram illustrating anti-tachycardia pacing by delivering synchronous pacing pulses to at least two different cardiac locations, according to some embodiments.

[0148] In some embodiments, the ATP pulses are delivered to at least two spaced apart cardiac locations, for example, via at least two device electrodes. In some embodiments, the electrodes contact at least two different locations along the ventricular septum. In some embodiments, the electrodes contact at least two different locations of the left ventricular wall. In some embodiments, the electrodes contact at least two different locations of the right ventricular wall. In some embodiments, one electrode contacts the left ventricular wall and another electrode contacts the right ventricular wall. In some embodiments, multiple electrodes contact the right ventricular tissue and multiple electrodes contact the left ventricular tissue.

[0149] In some embodiments, the parameters of the signal delivered through each of the two electrodes in the figure (shown as "Channel 1" and "Channel 2") are as described, for example, for FIG. 3A above. Note that the signal parameters are not limited to those described. Additional signal parameters for pacing pulses delivered to two or more locations may include, for example, amplitudes between 1-20V, 5-15V, 8-13V, or intermediate, higher or lower amplitudes, and may include, for example, widths between 0.1-20 ms, 1-10 ms, 5-15 ms, or intermediate, longer or shorter widths.

[0150] FIG. 6 is a flowchart of a method for adjusting the timing of anti-tachycardia pacing delivered to at least two different cardiac locations according to a measured time interval between R-wave occurrences at the two locations, according to some embodiments.

[0151] In some embodiments, a cardiac device, for example as described herein, is implanted (601).

[0152] In some embodiments, cardiac electrical activity is measured and / or estimated, for example during normal sinus rhythm. In some embodiments, R-wave occurrences are timed (603) via device electrodes, optionally placed at at least two different cardiac locations. In some embodiments, by timing the R-wave occurrences, the propagation of natural electrical signals can be estimated by determining the time interval between the occurrence of R-waves between the two different locations.

[0153] In some embodiments, a ventricular tachycardia episode is detected (605) if the measured heart rate exceeds a threshold, for example, greater than 160 BPM, greater than 187 BPM, greater than 200 BPM, greater than 230 BPM, or greater than an intermediate, higher or lower rate.

[0154] In some embodiments, ATP pulses delivered via at least two electrodes to at least two different cardiac locations are timed according to the measured R-wave occurrence interval (607).

[0155] In some embodiments, the order in which ATP pulses are delivered to at least two cardiac locations via at least two electrodes is set to match the natural propagation direction of action potentials, e.g., as occurs during normal cardiac function.

[0156] FIG. 7 illustrates anti-tachycardia pacing by delivering pacing pulses to at least two different cardiac locations that are timed according to the time interval between R-wave occurrences at the two locations.

[0157] In the illustrated examples, the ATP signal delivered through the second channel is provided with a delay of between 0.1-5 ms, 2-4 ms, 1-6 ms, or an intermediate, longer or shorter period from the ATP signal delivered through the first channel.

[0158] In some embodiments, the frequency of the ATP signal (e.g., the signal delivered through each channel) is selected to be high enough to override tachyarrhythmia episodes and restore normal sinus rhythm. In some embodiments, the ATP pulse rate is between 150-300 BPM, 200-600 BPM, 180-240 BPM, or an intermediate, higher, or lower rate.

[0159] In some embodiments, pulses are delivered to multiple cardiac sites (e.g., 2, 3, 4, 6 sites, or an intermediate, greater or lesser number of sites) according to a defined sequence, optionally preprogrammed into the device controller. Optionally, the sequence of delivery to the different sites is set according to the anatomical propagation of the signal throughout the cardiac tissue.

[0160] FIG. 8 is a flowchart of a method for delivering a pulse sequence combining wide and narrow pacing pulses to treat tachycardia, according to some embodiments.

[0161] In some embodiments, a cardiac device, for example as described herein, is implanted (801).

[0162] In some embodiments, when a ventricular tachycardia episode is detected (803), an ATP pulse sequence including a combination of wide pacing pulses (pulses of longer duration) and narrow pulses (pulses of shorter duration) is delivered (805) by the implantable device.

[0163] In some embodiments, the wide pacing pulses are between 2 and 10 ms in length, such as 3 ms, 5 ms, 8 ms, respectively, or intermediate, longer or shorter durations, In some embodiments, the narrow pacing pulses are between 0.2 and 2 ms in length, such as 0.5 ms, 1 ms, 1.5 ms, respectively, or intermediate, longer or shorter pulse durations.

[0164] In some embodiments, the amplitude of each pacing pulse is between 7-10 volts, between 5-8 volts, between 3-12 V, or an intermediate, greater or lesser amplitude. Optionally, the pulse amplitude is greater than 7 volts, greater than 8 volts, greater than 9 volts, or an intermediate, greater or lesser amplitude.

[0165] Various examples of ATP pulse sequences combining pulses of varying duration are shown in FIGS.

[0166] In the example of FIG. 9, the ATP pulse sequence includes a plurality of biphasic narrow pulses 901 (e.g., 1, 4, 6, 8, 10, 16, 20 pulses, or any intermediate, greater or smaller number) followed by a plurality of wide pulses 903 (e.g., 1, 4, 6, 8, 10, 16, 20 pulses, or any intermediate, greater or smaller number).

[0167] In the example of FIG. 10, the ATP pulse sequence includes an alternating pattern of a biphasic narrow pulse 1001 followed by a biphasic wide pulse 1003, and so on.

[0168] 11, the ATP pulse sequence includes biphasic pulses of increasing duration over time. Optionally, the pulse duration increases at regular intervals, such as 0.5 ms, 1 ms, 1.5 ms, 2 ms, or intermediate, longer or shorter times.

[0169] In the example of FIG. 12, the ATP pulse sequence includes successive pairs, each pair consisting of a narrow pulse 1201 (e.g., 0.2-1 ms long) and a wide pulse 1203 (e.g., 5-10 ms long). In some embodiments, each pair is delivered during a single cardiac cycle. In some embodiments, the wide pulse of the pair is timed to be delivered during the refractory period caused by the previous narrow pulse.

[0170] Alternatively, in some embodiments, each pair includes a wide pulse followed by a narrow pulse.

[0171] Optionally, the time interval between the start of the narrow pulse and the start of the wide pulse of each pair is between 20-50 ms, between 30-40 ms, between 10-30 ms, or an intermediate interval, longer or shorter. Optionally, the time interval between successive pairs (e.g., between the start of a first pair and the start of a successive second pair) is between 200-400 ms, 100-300 ms, 250-350 ms, or an intermediate interval, longer or shorter.

[0172] The terms "comprises," "comprising," "includes," "including," "having," and their conjugations mean "including but not limited to."

[0173] The term "consisting of" means "including, limited to."

[0174] The term "consisting essentially of" means that a composition, method, or structure may include additional ingredients, steps, and / or components, but only if the additional ingredients, steps, and / or components do not materially alter the basic and novel characteristics of the claimed composition, method, or structure.

[0175] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly indicates otherwise. For example, the term "a compound" or "at least one compound" can include a plurality of compounds, including mixtures thereof.

[0176] Throughout this application, various embodiments of the invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Thus, the description of a range should be considered to have specifically disclosed all possible subranges as well as each individual numerical value within that range. For example, description of a range such as 1-6 should be considered to have specifically disclosed subranges such as 1-3, 1-4, 1-5, 2-4, 2-6, 3-6, etc., and each individual numerical value within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0177] Whenever a numerical range is given herein, it is meant to include any recited numbers (fractional or integer) within the given range. The phrases "ranging / ranges between" a first designator number and a second designator number, and the phrases "ranging / ranges from" a first designator number "to" a second designator number, are used interchangeably herein and are meant to include the first designator number and the second designator number, and all fractional and integer numbers therebetween.

[0178] As used herein, the term "method" refers to manners, means, techniques, and procedures for accomplishing a given task, including, but not limited to, methods known by or readily developed from known manners, means, techniques, and procedures by practitioners of the chemical, pharmacological, biological, biochemical, and medical arts.

[0179] As used herein, the term "treating" includes negating, substantially inhibiting, slowing, or reversing the progression of a condition, substantially ameliorating the clinical or cosmetic symptoms of a condition, or substantially preventing the appearance of clinical or cosmetic symptoms of a condition.

[0180] It is understood that certain features of the invention that are described for clarity in the context of separate embodiments can also be provided in combination in a single embodiment. Conversely, various features of the invention that are described for brevity in the context of a single embodiment can also be provided separately or in any suitable subcombination or as preferred in any other described embodiment of the invention. Particular features described in the context of various embodiments should not be considered essential features of those embodiments, unless the embodiment is inoperable without those elements.

[0181] It is the intention of the applicants (applicants) that all publications, patents, and patent applications referenced herein are incorporated herein by reference in their entirety to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated herein by reference. Furthermore, citation or identification of any reference in this application should not be construed as an admission that such reference is available as prior art to the present invention. Section headings, if used, should not be construed as necessarily limiting. Additionally, any priority document(s) of this application are hereby incorporated herein by reference in their entirety.

Claims

1. at least two lead electrodes configured to contact intracardiac tissue; a housing containing circuitry for controlling and activating said at least two lead electrodes; a pulse generator configured to generate anti-tachycardia pacing pulses to be delivered by the at least two lead electrodes, the at least two lead electrodes configured to be positioned at at least two different intracardiac locations within a right ventricle; An implantable cardiac device comprising:

2. The device of claim 1 , wherein the endocardial tissue is one of the interventricular septum, the left ventricular wall, or the right ventricular wall.

3. The device of claim 1 , wherein the at least two different intracardiac locations are along the interventricular septum.

4. The device of claim 1 , wherein the at least two different intracardiac locations include a right ventricle and a left ventricle.

5. 5. The device of claim 1, wherein the circuitry is configured to detect a tachycardia episode and the pulse generator is configured to deliver a defibrillation pulse if a detected tachycardia episode continues after delivery of the anti-tachycardia pacing pulse.

6. The device of claim 5 , wherein the circuitry is configured to detect the tachycardia episodes by measuring R-R intervals via the at least two lead electrodes.

7. 7. The device of claim 6, wherein the circuitry is configured to detect the tachycardia episode upon measuring a heart rate between 180 and 250 BPM.

8. The device of claim 1 , wherein the anti-tachycardia pacing pulses are biphasic pulses.

9. 10. The device of claim 1, wherein the pulse generator is configured to generate synchronized anti-tachycardia pacing pulses to be delivered via the at least two lead electrodes.

10. 10. The device of claim 9, wherein the pulse generator is configured to simultaneously generate the anti-tachycardia pacing pulses.

11. 10. The device of claim 9, wherein the pulse generator is configured to generate the synchronized anti-tachycardia pacing pulses with a time delay between them such that a pulse applied via one of the two lead electrodes is delivered at a predetermined time delay from a pulse applied via the other of the at least two lead electrodes.

12. 12. The device of claim 11, wherein the predetermined time delay is selected according to a time difference between R-wave occurrences measured via the at least two electrodes at the at least two different cardiac locations during normal cardiac function.

13. 10. The device of claim 1, wherein the circuitry comprises a memory that stores a plurality of anti-tachycardia pacing pulse sequences and a controller configured to execute delivery of a selected anti-tachycardia pacing pulse sequence.

14. The cardiac device comprises: delivering a cardiac contractility modulation stimulus having a duration between 5-10 milliseconds and an amplitude between 5-10 V during normal sinus rhythm; delivering a defibrillation shock; The device of claim 1 , further configured for one or more of:

15. 10. The device of claim 1, wherein the pulse generator is configured to generate a combination of anti-tachycardia pacing pulses having different durations selected from between 5 and 10 milliseconds within the same anti-tachycardia pulse sequence.

16. The device of claim 1, wherein the anti-tachycardia pacing pulse comprises at least one of a duration between 0.1 and 10 milliseconds and an amplitude between 5 and 10 V.

17. The device of claim 1, wherein the anti-tachycardia pacing pulse comprises at least one of a duration between 5 and 10 milliseconds and an amplitude between 5 and 10 V.

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