Asynchronous detection in cardiac conduction system pacing system

Abstract

An implantable medical device includes a plurality of implantable electrodes for sensing and pacing a heart of a patient. The plurality of electrodes includes cardiac conduction system electrodes positionable proximate a portion of a cardiac conduction system of a patient. A computing device includes processing circuitry and is operably coupled to a plurality of implantable electrodes. A computing device monitors a precardiac ejection (HS-PEP) of a heart of a patient. A change in the HS-PEP is determined based on the monitoring. A change in HS-PEP is determined to be greater than or equal to a specified threshold. Delivery of cardiac conduction system pacing therapy to the cardiac conduction system of the patient using the cardiac conduction system electrode is initiated based on the HS-PEP being greater than or equal to a specified threshold.

Description

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 541,409, filed September 29, 2023, the entire contents of which are incorporated herein by reference. Summary of the Invention

[0002] An exemplary implantable medical device includes multiple implantable electrodes for sensing and pacing a patient's heart. The multiple electrodes include cardiac conduction system electrodes capable of being positioned close to a portion of the patient's cardiac conduction system. A computing device includes processing circuitry and is operatively coupled to the multiple implantable electrodes. The computing device is configured to monitor the sound-heart-ejection pre-purge (HS-PEP) of the patient's heart. Based on this monitoring, changes in HS-PEP are determined. It is determined that the change in HS-PEP is greater than or equal to a specified threshold. Based on the HS-PEP being greater than or equal to the specified threshold, cardiac conduction system pacing therapy is initiated to deliver cardiac conduction system pacing treatment to the patient's cardiac conduction system using the cardiac conduction system electrodes.

[0003] An exemplary implantable defibrillator includes multiple implantable electrodes for sensing and pacing a patient's heart. The multiple implantable electrodes include coil electrodes and cardiac conduction system electrodes that can be positioned close to a portion of the patient's cardiac conduction system. The implantable defibrillator includes a computing device with processing circuitry. The computing device is operatively coupled to the multiple implantable electrodes. The computing device is configured to monitor the patient's sound-of-heart ejection phase (HS-PEP). Based on this monitoring, changes in HS-PEP are determined. A change in HS-PEP is determined to be greater than or equal to a specified threshold. Based on HS-PEP being greater than or equal to the specified threshold, cardiac conduction system pacing therapy is initiated to deliver cardiac conduction system pacing treatment to the patient's cardiac conduction system using the cardiac conduction system electrodes.

[0004] An exemplary method includes monitoring the pre-ejection phase of the heartbeat in a patient's heart (HS-PEP). Changes in HS-PEP are determined based on this monitoring. A change in HS-PEP is determined to be greater than or equal to a specified threshold. Based on HS-PEP being greater than or equal to the specified threshold, cardiac conduction system pacing therapy is initiated to deliver cardiac conduction system electrodes to the patient's cardiac conduction system.

[0005] The above overview is not intended to describe every embodiment or every implementation of this disclosure. A more complete understanding will become apparent and understood by taking into account the accompanying drawings and the following detailed description and claims. Attached Figure Description

[0006] Figure 1 This is a diagram of the patient's heart.

[0007] Figure 2AThis is a conceptual diagram illustrating an exemplary treatment system configured to provide cardiac conduction system pacing therapy to the His bundle using leads placed in the right atrium.

[0008] Figure 2B It is shown Figure 2A A more detailed conceptual diagram of an exemplary treatment system.

[0009] Figure 2C It is shown Figure 2A An exemplary treatment system, but only includes a detailed conceptual diagram of two leads.

[0010] Figure 2D It is shown Figure 2A An exemplary treatment system, but only a detailed conceptual diagram of a single lead.

[0011] Figure 3A is a conceptual diagram illustrating an exemplary treatment system configured to provide cardiac conduction system pacing therapy to the left bundle branch using leads placed in the right ventricle.

[0012] Figure 3B is a close-up view of the lead wire in the heart of the patient in Figure 3A.

[0013] Figure 4A This is a conceptual diagram of an exemplary treatment system configured to provide cardiac conduction system pacing therapy to the left and / or right bundle branch using leads placed in the right ventricle.

[0014] Figure 4B It is shown Figure 4A A detailed concept diagram of an exemplary treatment system, but only including two leads.

[0015] Figure 5 It is shown Figures 2A to 2D A functional block diagram illustrating an example configuration of an implantable medical device.

[0016] Figure 6A and Figure 6B Examples of heart sound signal features that can be used to monitor cardiac asynchrony are illustrated.

[0017] Figure 7 The method for determining whether delivery is possible is shown. Figures 1 to 5 An exemplary method of treatment using a device with a conduction system 700.

[0018] Figure 8 The method for determining whether delivery is possible is shown. Figures 1 to 5 Another exemplary method of treatment using the device and its conduction system 800. Detailed Implementation

[0019] In the following detailed description of exemplary embodiments, reference is made to the accompanying drawings, which form part of these embodiments, and specific practical embodiments are illustrated in the drawings by way of example. It should be understood that other embodiments may be utilized and structural changes may be made without departing from (e.g., still falling within) the scope of this disclosure herein.

[0020] Reference Figures 1 to 8 Illustrative apparatuses and methods are described. It will be apparent to those skilled in the art that elements or processes of one embodiment can be used in combination with elements or processes of other embodiments, and that possible embodiments of such apparatuses and methods using combinations of features set forth herein are not limited to those shown in the figures and / or the specific embodiments described herein. Furthermore, it will be appreciated that the embodiments described herein may include many elements that are not necessarily shown to scale. Even further, it will be appreciated that the timing of the processes and the size and shape 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 sizes, or element types may be preferred over others.

[0021] Figure 1 A schematic diagram of the heart 12 is depicted, and Figures 2 through 4 depict conceptual diagrams illustrating exemplary treatment systems that can be used to provide treatment to the heart 12 of a patient 14. The patient 14 is typically, but not necessarily, a person. Figures 2A to 2B As shown, the treatment system 10 may include an IMD 16 connected to three leads 18, 20, 23 and a programmer 24. The IMD 16 may be an implantable pacemaker, cardioverter-defibrillator, and / or defibrillator that provides electrical pulses to the heart 12, for example, via electrodes connected to one or more of the leads 18, 20, 23. Other non-limiting examples of the IMD 16 include pacemakers with medical leads, implantable cardioverter-defibrillators (ICDs), intracardiac devices, leadless pacemakers (LPDs), subcutaneous ICDs (S-ICDs), and subcutaneous medical devices (e.g., neurostimulators, insertable monitoring devices, etc.).

[0022] Leads 18, 20, and 23 may extend into the heart 12 of the patient 14 to sense the electrical activity of the heart 12 and / or deliver electrical stimulation to the heart 12. Figure 2AIn the example shown, the right ventricular lead 18 extends through one or more veins (not shown), the superior vena cava (not shown), and the right atrium 26, and enters the right ventricle 28. The left ventricular coronary sinus lead 20 extends through one or more veins, the vena cava, the right atrium 26, and enters the coronary sinus 30 to reach the region of the free wall of the left ventricle 32 adjacent to the heart 12. The cardiac conduction system pacing leads 23 (e.g., left bundle branch pacing lead, right bundle branch pacing lead, His bundle pacing lead, etc.) extend through one or more veins and the vena cava, and enter the right atrium 26 of the heart 12 to pace the cardiac conduction system (e.g., through the Koch triangle, near and / or directly in contact with the left bundle branch 8a, near and / or directly in contact with the right bundle branch 8b, near and / or directly in contact with the His bundle 13, etc.). In some embodiments, the cardiac conduction system pacing therapy lead 23 may be positioned within approximately 1 mm of a portion of the cardiac conduction system (such as the His bundle 13), or along the RV septal wall adjacent to either the left bundle branch (LBB) 8a or the right bundle branch 8b. In one or more embodiments, the cardiac conduction system therapy lead may be further positioned or placed through the tricuspid valve into the right ventricle 28 and implanted in the interventricular septum (VS), for example, approximately 1 to 2 cm in the apical direction, as will be referred to herein with reference to Figures 3A to 3B and Figures 4A to 4B Further as described. An example of a cardiac conduction system pacing therapy lead (e.g., a His lead) could be SELECTSECURE. ™ 3830. SELECT SECURE ™ For a description of the 3830, please refer to Medtronic's model SELECTSECURE. ™ 3830 Manual (2013), the full text of which is incorporated herein by reference. SELECTSECURE ™ 3830 includes two or more conductors, with or without lumens.

[0023] As used herein, cardiac conduction system pacing therapy refers to any pacing therapy configured to deliver pacing therapy (e.g., pacing pulses, electrical stimulation, etc.) to a cardiac conduction system, including, for example, the His bundle 13, left bundle branch 8a (e.g., LBB area pacing (LBBAP)), right bundle branch 8b, LBB-optimized cardiac resynchronization therapy (LOT-CRT), etc. As used herein, the term “activation” refers to a sensed or paced event. For example, atrial activation may refer to an atrial sensing or event (As) or atrial pacing or atrial pacing artifact (Ap). As will be described herein, atrial sensing can be detected or identified in one or more different signals monitored using one or more different devices or sensors located in one or more different locations. For example, atrial sensing can be detected in near-field electrical signals from electrodes positioned in the right atrium. Furthermore, for example, atrial sensing can be detected in far-field electrical signals from electrodes positioned outside the right atrium (such as in the right ventricle or ventricular septum). Furthermore, for example, atrial sensing can be detected in the far-field signal from a mechanical cardiac activation sensor, such as an accelerometer or microphone (e.g., a heart sound sensor) located in or outside the right atrium (e.g., in the right ventricle, ventricular septum, or another part of the patient's body). Similarly, ventricular activation can refer to a ventricular sensing or event (Vs) or ventricular pacing or ventricular pacing artifact (Vp), which can be described as a ventricular stimulation pulse. In some embodiments, activation intervals from As or Ap to Vs or Vp and from Vp to Vs can be detected. Specifically, activation intervals can include the pacing (Ap or Vp) to ventricular interval (left or right ventricular sensing) or the atrial sensing (As) to ventricular sensing interval (left or right ventricle).

[0024] An exemplary IMD can be described as delivering one or both of conventional pacing therapy and cardiac conduction system pacing therapy. Conventional or traditional pacing therapy can be described as delivering pacing pulses to myocardial tissue that is not part of the patient's cardiac conduction system, such that, for example, the pacing pulse triggers electrical activation that propagates primarily from one myocardial cell to another (also known as "cell-to-cell"), as opposed to propagation within the cardiac conduction system prior to myocardial tissue. For example, conventional pacing therapy may deliver pacing pulses directly to muscular cardiac tissue (e.g., myocardial tissue) that is to be depolarized to provide cardiac contraction. For example, conventional left ventricular pacing therapy may utilize an implanted left ventricular coronary sinus lead 20 extending through one or more veins, the vena cava, the right atrium 26, and into the coronary sinus 30 to reach a region adjacent to the free wall of the left ventricle 32 of the heart 12, to deliver pacing pulses to the myocardial tissue of the free wall of the left ventricle 32.

[0025] An exemplary left ventricular lead 20 having a set of spaced-apart electrodes is shown in U.S. Patent Publication No. WO 2019 / 104174 A1, filed May 4, 2012, by Ghosh et al., the entire contents of which are incorporated herein by reference. Exemplary electrodes on leads for forming pacing vectors are shown and described in U.S. Patent Nos. 8,355,784 B2 and 8,126,546, the entire contents of which are incorporated herein by reference.

[0026] Additionally, pacing leads 18, 20, and 23 can be used to deliver pacing of the left ventricle or left ventricular septum to the ventricular septum wall. At least one of the pacing leads 18, 20, and 23 may extend through one or more veins, the vena cava, the right atrium 26, and into the coronary sinus 30 to reach the region adjacent to the septal wall of the left ventricle 32 of the heart 12.

[0027] Exemplary cardiac conduction system pacing therapy can be described, for example, in U.S. Patent Application Publication No. 2019 / 0111270 A1, entitled "HisBundle and Bundle Branch Pacing Adjustment," published April 18, 2019, the entire contents of which are incorporated herein by reference. Exemplary left ventricular septal pacing can be described, for example, in U.S. Patent Application Serial No. 16 / 521,000, entitled "AV Synchronous Septal Pacing," filed July 24, 2019, the entire contents of which are incorporated herein by reference.

[0028] One or more elongated conductors of any one of leads 18, 20, and 23 may extend through the hermetically sealed feedthrough assembly and within the insulating tubular member of the respective lead, and may electrically connect an electrical pulse generator (enclosed within the housing) to one or more electrodes, such as, for example, loop electrodes, tip electrodes, spiral electrodes, etc. The conductors may be formed of one or more conductive wires in a coiled or cabled configuration, comprising, for example, an MP35N alloy known to those skilled in the art, and the insulating tubular member may be any suitable medical-grade polymer, such as polyurethane, silicone rubber, or blends thereof. According to one or more exemplary embodiments, the flexible lead body may extend a predetermined length (e.g., about 10 cm to about 20 cm, or about 15 cm to 20 cm) from the proximal end to the distal end. The size of the lead body may be less than about 7 French (FR), but is typically in the range of about 3 FR to 4 FR. In one or more embodiments, a lead body of about 2 FR to about 3 FR size is used.

[0029] Cardiac conduction system pacing may include at least one of His bundle pacing and left bundle branch pacing and / or right bundle branch pacing. Bundle branch pacing can bypass pathological areas and may have a low and stable pacing threshold. In some embodiments, only one of the left or right bundle branches may be paced using one or more pacing leads. In another embodiment, both bundle branches may be paced simultaneously (e.g., bi-bundle branch pacing), which mimics the inherent activation propagation via the His bundle-Purkinje conduction system, for example, pacing activation propagates through both bundle branches to both ventricles for synchronized contraction. On the other hand, His bundle pacing typically paces the His bundle located proximal to the bundle branch. In some embodiments, the IMD 16 may include one, two, or more electrodes located in one or more bundle branches configured for bundle branch pacing.

[0030] In some embodiments, the IMD 16 may be an intracardiac pacemaker or leadless pacing device (LPD) configured as one or more parts of a pacing cardiac conduction system, such as a His bundle. As used herein, “leadless” means a device without leads extending out of the heart 12. In other words, the leads of a leadless device may not extend from the outside of the heart to the inside. Some leadless devices may be introduced through a vein, but once implanted, a leadless device has no or may not include any transvenous leads and may be configured to provide cardiac therapy without the use of any transvenous leads. In one or more embodiments, when the housing of the device is positioned in the atrium, an exemplary LPD for bundle pacing does not use leads to be operatively connected to an electrode disposed near the diaphragm. Leadless electrodes may be coupled to the housing of the medical device without leads, without the need for leads between the electrode and the housing.

[0031] IMD 16 can be connected to at least one of leads 18, 20, 23, as shown in the image. Figure 2B Various electrodes are shown to sense electrical signals accompanying the depolarization and repolarization of the heart 12. In some examples, the IMD 16 provides pacing pulses to the heart 12 based on the electrical signals sensed within the heart 12. The electrodes of the IMD 16 used for sensing and pacing can be configured as unipolar or bipolar.

[0032] The IMD 16 can also provide defibrillation and / or cardioversion therapy via electrodes located on at least one of leads 18, 20, and 23. For example, the IMD 16 can detect atrial arrhythmias of heart 12, such as atrial fibrillation of atria 26 and 33, and can then deliver defibrillation therapy to heart 12 in the form of electrical pulses. The IMD 16 can also detect ventricular arrhythmias of heart 12, such as ventricular fibrillation of ventricles 28 and 32, and can then deliver defibrillation therapy to heart 12 in the form of electrical pulses. In some examples, the IMD 16 can be programmed to deliver a treatment process, such as pulses with increasing energy levels, until the fibrillation of heart 12 stops. The IMD 16 can employ one or more fibrillation detection techniques known in the art to detect fibrillation.

[0033] In some examples, such as Figure 2A The programmer 24 shown can be a handheld computing device, a computer workstation, or a mobile phone. The programmer 24 may include a user interface for receiving input from a user. The user interface may include, for example, a keypad and a display, which may be, for example, a cathode ray tube (CRT) display, a liquid crystal display (LCD), or a light-emitting diode (LED) display. The keypad may take the form of an alphanumeric keypad associated with specific functions or a reduced set of keys. The programmer 24 may additionally or alternatively include a peripheral pointing device (such as a mouse) through which the user can interact with the user interface. In some embodiments, the display of the programmer 24 may include a touchscreen display, through which the user can interact with the programmer 24. Through the graphical user interface on the programmer 24, the user can configure one or more pacing therapies, select one or more pacing modes, etc.

[0034] Additionally, various pacing settings can be adjusted or configured based on various sensed signals. For example, various near-field and far-field signals can be sensed by one or more electrodes of the IMD 16 and / or other devices operatively coupled thereto. For example, the P-wave to R-wave interval can be monitored or measured within the near-field or far-field signals and can then be used to adjust, configure, and select cardiac conduction system pacing therapy. Furthermore, for example, the QRS width can be monitored or measured within the near-field or far-field signals and can then be used to adjust, configure, and select cardiac conduction system pacing therapy. Furthermore, for example, one or more of the following can be monitored or measured within the near-field or far-field signals: P-wave to R-wave consistency, T-wave to P-wave consistency, and P-wave morphology consistency, and can then be used to adjust, configure, and select cardiac conduction system pacing therapy.

[0035] The exemplary treatment systems described herein (such as the IMD 16) can be used to deliver cardiac conduction system pacing therapy in various modes, such as suppression pacing mode, ventricular fusion pacing mode, atrioventricular synchronous pacing mode, atrial fibrillation pacing mode, etc.

[0036] Ventricular fusion pacing modes can be configured to deliver cardiac conduction system pacing therapy to provide effective ventricular fusion. Effective ventricular fusion can be described as synchronizing the timing of left ventricular activation with activation on the right ventricle. For example, in a fusion pacing configuration, the medical device can deliver one or more pacing pulses to pre-excite the left ventricle and synchronize left ventricular depolarization with the depolarization of the earlier-contracting right ventricle. Left ventricular activation may be “fused” (or “merged”) with right ventricular activation, due to the heart’s inherent conduction. In this way, the inherent and pacing-induced excitation wavefronts can be merged, thereby resynchronizing left ventricular depolarization with right ventricular depolarization.

[0037] As used herein, the term "far-field" electrical signal refers to the result of measuring cardiac activity using sensors (such as electrodes) positioned outside the region of interest. For example, a far-field electrical signal representing the electrical activity of a patient's cavity of interest can be measured from electrodes positioned in an adjacent cavity (i.e., a different cavity adjacent to or near the cavity of interest). More specifically, for example, atrial electrical activity representing depolarization of one or both atria, or electrical activity originating from one or more bilateral atria, can be monitored in a far-field electrical signal measured using electrodes positioned outside the right atrium (such as in the right or left ventricle) or within the ventricular septum. As used herein, the term "near-field" electrical signal refers to the result of measuring cardiac activity using sensors (such as electrodes) positioned near the region of interest. For example, an electrical signal measured from an electrode located on the left side of a patient's ventricular septum is an example of a near-field electrical signal for the patient's left ventricle.

[0038] P-wave timing is the time at which a P-wave is detected. Typically, P-wave timing includes the time using the maximum first derivative (or maximum P-wave value) of the rising edge of the P-wave. P-wave timing is also used in device marking channels to indicate P-wave timing or atrial activation time. P-wave timing can be determined using near-field signals obtained from sensors (e.g., electrodes, accelerometers, heart sound sensors, etc.) located in the atrium (e.g., the right atrium) and / or far-field signals obtained from sensors (e.g., electrodes, accelerometers, heart sound sensors, etc.) located outside the atrium (e.g., the right atrium) (such as in the right ventricle and / or ventricular septum).

[0039] R-wave timing is the time at which a QRS complex is detected. Typically, R-wave timing includes the time using the maximum first derivative (or maximum R-wave value) of the rising edge of the R-wave. R-wave timing is also used in device channel marking to indicate R-wave timing or ventricular activation time.

[0040] Users (such as physicians, technicians, or other clinicians) can interact with programmer 24 to communicate with IMD 16. For example, users can interact with programmer 24 to retrieve physiological or diagnostic information from IMD 16. Additionally, users can also interact with programmer 24 to program IMD 16, for example, by selecting values ​​for operating parameters of IMD 16. IMD 16 and programmer 24 can communicate wirelessly using any technology known in the art. Examples of communication technologies may include, for example, low-frequency or radio-frequency (RF) telemetry, but other technologies are also contemplated. In some examples, programmer 24 may include a programming head that can be placed near the IMD 16 implantation site close to the patient's body to improve the quality or safety of communication between IMD 16 and programmer 24.

[0041] Figure 2B This is a conceptual diagram showing the IMD 16 and leads 18, 20, 23 of the treatment system 10 in more detail. The three-chamber IMD 16 can be used for cardiac rhythm therapy and defibrillation or cardioversion therapy (CRT-D). Leads 18, 20, 23 can be electrically connected to a stimulator, sensing module, or other modules of the IMD 16 via connector block 34. In some examples, the proximal ends of leads 18, 20, 23 may include electrical contacts that are electrically connected to corresponding electrical contacts within connector block 34. Furthermore, in some examples, leads 18, 20, 23 can be mechanically connected to connector block 34 by means of retaining screws, connecting pins, or another suitable mechanical coupling mechanism.

[0042] Each of leads 18, 20, and 23 includes an elongated, insulated lead body that carries several concentric coiled conductors separated from each other by a tubular insulating sheath. In the example shown, an optional pressure sensor 38, along with bipolar electrodes 40 and 42, is positioned near the distal end of the right ventricular lead 18. Additionally, bipolar electrodes 44 and 46 are positioned near the distal end of the left ventricular lead 20, and bipolar electrodes 48 and 50 are positioned near the distal end of the cardiac conduction pacing lead 23. The cardiac conduction system pacing electrode 50 can be used for pacing and / or sensing of cardiac conduction system tissues (e.g., His bundle tissues or bundle branch tissues).

[0043] exist Figure 2BIn this embodiment, pressure sensor 38 is disposed within the right ventricle 28 and is responsive to absolute pressure within the right ventricle 28. Pressure sensor 38 may be, for example, a capacitive or piezoelectric absolute pressure sensor. In other examples, pressure sensor 38 may be located in other regions of the heart 12 and may monitor pressure in one or more of these other regions, or pressure sensor 38 may be located elsewhere within or near the cardiovascular system of the patient 14 to monitor cardiovascular pressure associated with the mechanical contraction of the heart. Optionally, a pressure sensor in the pulmonary artery communicating with IMD 16 may be used.

[0044] Electrodes 40, 44, and 48 may be in the form of ring electrodes, and electrodes 42, 46, and 50 may be in the form of extendable and / or fixed spiral-tipped electrodes respectively mounted within insulated electrode heads 52, 54, and 56. Each of electrodes 40, 42, 44, 46, 48, and 50 may be electrically connected to a corresponding coil conductor within the lead body of its associated lead 18, 20, and 23, and thereby connected to a corresponding electrical contact in an electrical contact at the proximal end of lead 18, 20, and 23.

[0045] Electrodes 40, 42, 44, 46, 48, and 50 can sense electrical signals accompanying depolarization and repolarization of the heart 12. These electrical signals are conducted to the IMD 16 via corresponding leads 18, 20, and 23. In some examples, the IMD 16 also delivers pacing pulses via electrodes 40, 42, 44, 46, 48, and 50 to induce depolarization of the cardiac tissue of the heart 12. In some examples, such as... Figure 2B As shown, the IMD 16 may include one or more housing electrodes (such as housing electrode 58) that may be integrally formed with or otherwise coupled to the outer surface of the hermetically sealed housing 60 of the IMD 16. In some examples, housing electrode 58 may be defined by a non-insulated portion of the outward-facing portion of the housing 60 of the IMD 16. Two or more housing electrodes may be defined by additional separations between the insulating and non-insulated portions of the housing 60. In some examples, housing electrode 58 substantially encompasses the entire housing 60. Any of electrodes 40, 42, 44, 46, 48, 50 may be used in conjunction with housing electrode 58 for unipolar sensing or pacing, or for bipolar sensing having two electrodes in the same pacing lead. In one or more embodiments, housing 60 may encapsulate a stimulation generator that generates cardiac pacing pulses and defibrillation or cardioversion shocks (see [link to relevant documentation]). Figure 5 ), and a sensing module for monitoring the patient's heart rhythm.

[0046] Leads 18, 20, and 23 may also include elongated electrodes 62, 64, and 66, which may be in the form of coils. The IMD 16 can deliver a defibrillation shock to the heart 12 via any combination of the elongated electrodes 62, 64, and 66 and the housing electrode 58. Electrodes 58, 62, 64, and 66 can also be used to deliver cardioversion pulses to the heart 12. Electrodes 62, 64, and 66 may be made of any suitable conductive material, such as, but not limited to, platinum, platinum alloys, or other materials known to be suitable for use in implantable defibrillation electrodes.

[0047] Pressure sensor 38 can be coupled to one or more coil conductors within lead 18. Figure 2B In this embodiment, the pressure sensor 38 is located on lead 18 further away from the elongated electrode 62. In other examples, the pressure sensor 38 may be positioned closer to the elongated electrode 62, rather than distal to it. Furthermore, in other examples, the pressure sensor 38 may be coupled to another lead among leads 20, 23, or to leads other than those carrying the stimulation and sensing electrodes 18, 20, 23. Additionally, in some examples, the pressure sensor 38 may be a stand-alone device implanted within the heart 12 (such as within the ventricular septum separating the right ventricle 28 from the left ventricle 32, or within the atrial septum separating the right atrium 26 from the left atrium 33). In such examples, the pressure sensor 38 may communicate wirelessly with the IMD 16.

[0048] Figures 2C to 2D These are additional conceptual diagrams illustrating examples of a dual-chamber treatment system 70 and a single-chamber treatment system 71, respectively. Treatment system 70 is similar to... Figures 2A to 2B Treatment system 70 includes two leads 18 and 23 instead of three leads. Treatment system 70 can utilize an IMD 16 configured to deliver or perform dual-chamber pacing. Leads 18 and 23 are implanted in the right ventricle 28 and right atrium 26 to pace one or more portions of the cardiac conduction system, such as the His bundle or one or two bundle branches, respectively. Treatment system 71 is similar to Figures 2A to 2B The treatment system 10 includes a single lead 23 instead of three leads. The treatment system 71 can utilize an IMD 16 configured to deliver or perform single-chamber pacing. The lead 23 is implanted in the right atrium 26 to individually pace one or more portions of the cardiac conduction system, such as the His bundle or one or two bundle branches.

[0049] The cardiac conduction system pacing lead 23 may include an electrode 50 in a helical form (also referred to as a helical electrode), which may be positioned near, adjacent to, or within a region or portion of the cardiac conduction system, such as, for example, the ventricular septum, Koch's triangle, His bundle, left and right bundle branch tissues, and / or right bundle branch tissues. The cardiac conduction system pacing lead 23 may be configured as a bipolar or quadripolar lead for use with a pacemaker device, a CRT-P device, or a CRT-ICD.

[0050] Figures 3A and 3B illustrate the heart 12 of a patient with an implanted medical electrical lead 723 coupled to an IMD 716 to deliver bundle branch pacing according to an example of an IMD system 710. Figure 3B is a close-up view of the lead 723 in the heart 12 of the patient in Figure 3A. In some embodiments, the electrical lead 723 may be the only lead implanted in the heart 12. In other embodiments as discussed herein, multiple leads may be present in the heart 12. For example, one or more implantable electrodes may include pacing electrodes that can be implanted close to the cardiac conduction system or implanted in the ventricular septum (VS) to deliver cardiac conduction system pacing therapy.

[0051] In one embodiment, lead 723 can be configured for dual-bundle pacing, and lead 723 can be coupled with... Figures 2A to 2B The lead 723 shown is the same as or similar to that shown in the diagram, except that the lead 723 is implanted near the bundle branch in the ventricular septum (VS) from the right ventricle 28, rather than, for example, the His bundle 13. As shown, the lead 723 is implanted from the right ventricle 28 toward the left ventricle 32 in the septal wall or ventricular septum. The lead 723 may not pierce the wall of the left ventricle 32 or extend into the left ventricular cavity. Electrode 752 and tissue-piercing electrode 761 may be disposed on the distal end portion of the lead 723, which may also be described as an axis. Electrode 752 and tissue-piercing electrode 761 may be associated with, for example, Figure 2B The electrodes shown are the same as or similar to the tissue-puncturing electrode 50, except that electrode 752 is configured as a cathode electrode to sense or pace the right bundle branch and electrode 761 is configured to sense or pace the left bundle branch, for example, during dual bundle branch pacing. Therefore, electrode 752 can be implanted near the right bundle branch 8b, and electrode 761 can be implanted near the left bundle branch 8a. Electrode 761 can be described as a monopolar cathode electrode, which can be implanted on the left side of the patient's ventricular septum. Electrode 752 can be described as a monopolar cathode electrode, which can be implanted on the right side of the patient's ventricular septum.

[0052] During dual-bundle branch pacing, both electrodes 752 and 761 can deliver cathode pulses to achieve synchronous activation or excitation of the right bundle branch 8b and the left bundle branch 8a, which can lead to synchronous activation of the right ventricle 28 and the left ventricle 32. In some embodiments, pulses can be delivered simultaneously to achieve synchronization. In other embodiments, pulse delivery can be delayed to achieve synchronization.

[0053] Although the lead 723 shown is configured to perform dual bundle branch pacing using electrodes 752 and 761, it should be understood that lead 723 or similar leads are considered herein to include only one of electrodes 752 and 761, and are therefore only configured to deliver cardiac conduction system pacing therapy to one of the right bundle branch and the left bundle branch.

[0054] Additionally, lead 723 may include a right atrial electrode 770 arranged along lead 723 closer to electrodes 752 and 761. Right atrial electrode 770 may be located in or near the right atrium 26 and may serve as the anode for cathode pulses from electrodes 752 and / or 761. Furthermore, right atrial electrode 770 may provide atrial sensing for, for example, sensing atrial depolarization or activation, sensing or detecting atrial fibrillation, etc. Although lead 723 is shown to include right atrial electrode 770, it should be understood that lead 723 may not include right atrial electrode 770, but may include only one or both of electrodes 752 and 761.

[0055] Additionally, the device system 710 may include a mechanical cardiac activation sensor 751 coupled to the lead 723, as shown in FIG3B. As illustrated in this embodiment, the mechanical cardiac activation sensor 751 may be positioned within the right ventricle 28 when the distal end of the lead 723 is implanted into the ventricular septum through the right ventricle 28. The mechanical cardiac activation sensor 751 may be a motion sensor (e.g., an accelerometer) and / or a heart sound sensor (e.g., a microphone), which can be used to determine atrial activation or depolarization (e.g., atrial vasodilation) for delivery of atrioventricular timing cardiac conduction system pacing therapy. In other words, the device system 710 may be configured to monitor the mechanical activity of a patient's heart using the mechanical cardiac activation sensor, determine atrial activation based on the monitored mechanical activity, and deliver cardiac conduction system pacing using cardiac conduction system pacing electrodes based on the determined atrial activation. Additionally, in one or more embodiments, the mechanical cardiac activation sensor 751 may be located within the housing of the IMD 716, which is not located within the patient's heart. For example, the housing of the IMD 716 may be subcutaneously positioned with respect to the patient's body. Furthermore, if the device system 710 includes a leadless device, the mechanical heart activation sensor 751 may be located in the housing of the leadless device implanted in the right ventricle 28.

[0056] Furthermore, atrial activation determined using the mechanical cardiac activation sensor 751 can be used in conjunction with atrial activation determined using near-field or far-field electrical activity. In at least one embodiment, atrial activation determined using the mechanical cardiac activation sensor 751 can be used to confirm atrial activation determined using near-field or far-field electrical activity, or vice versa.

[0057] Figure 4A This is a conceptual diagram of an exemplary system 801, which includes an IMD or pacemaker 814 configured as a multi-chamber pacemaker, a right atrial pacing and sensing lead 919, a coronary sinus lead 992, and a cardiac conduction system pacing lead 918 configured to deliver bundle branch pacing. The IMD 814 is shown coupled to the right atrial lead 919, which carries a pacing tip electrode 936 and a proximal loop electrode 938 for sensing right atrial signals and delivering atrial pacing to the right atrium. The coronary sinus lead 992 can be advanced into the RA, passing through the coronary sinus ostium and into the cardiac vein of the left ventricle to position electrodes 94a, 94b, 94c, 94d (collectively referred to as “CS electrodes 94”) on the epicardium along the left ventricular myocardium to sense electrocardiographic signals and pace the left ventricular myocardium. The coronary sinus lead 992 is shown as a quadrupole lead carrying four electrodes 94a to 94d, which can be selected from various bipolar pacing electrode pairs to pace left ventricular myocardial tissue and sense left ventricular epicardial electrocardiogram signals. One of the CS electrodes 94 can be selected in conjunction with the pacemaker housing 815 or the coil electrode 935 to deliver unipolar left ventricular myocardial pacing and / or sense unipolar ventricular electrocardiogram signals.

[0058] In this example, the IMD 814 may be able to deliver a high-voltage cardioversion / defibrillation pulse therapy for cardioversion or defibrillation in response to the detection of a ventricular tachyarrhythmia. Therefore, lead 918 is shown carrying a coil electrode 935 for delivering the high-voltage pulse. In various examples, one or more coil electrodes may be included along one or more leads 918, 919, or 992. The coil electrode, such as coil electrode 935, may be selected in a unipolar pacing electrode vector along with any of the lead-based tip or loop electrodes 932, 934, 936, 938, or 94 to sense unipolar electrocardiographic signals for analyzing and determining ventricular conduction status. In some cases, coil electrode 935 may be used with housing 815 to sense near-field electrocardiographic signals for determining atrial depolarization or activation, etc.

[0059] When the pacing lead 918 is positioned for bundle branch pacing to deliver one or both bundle branches, cardiac conduction system pacing therapy can be combined with conventional ventricular myocardial pacing of the left ventricle using the coronary sinus lead 992 to correct left ventricular conduction delay and achieve electrical and mechanical synchronization of the left and right ventricles. Therefore, in some examples, one or more processors, one or more processing circuits, or computing devices of the IMD 814 can select cardiac conduction system pacing therapy plus conventional left ventricular myocardial pacing therapy, which includes, for example, a combination of single-bundle branch pacing or dual-bundle branch pacing (e.g., using lead 918) with left ventricular myocardial pacing using the coronary sinus lead 992. Figure 4B It is another one that is basically similar to Figure 4A The conceptual diagrams of the exemplary treatment system 801 and the exemplary treatment system 802 are shown, except that the system 802 does not include the coronary sinus lead 992.

[0060] Figure 2A The configuration of treatment system 10 shown in Figure 4 is merely illustrative. In other examples, the treatment system may include epicardial leads and / or patch electrodes to replace or supplement the transvenous leads 18, 20, 23 illustrated in Figures 2 through 4, or other configurations shown, described, or incorporated herein by reference. Additionally, IMDs 16, 716, 814 do not need to be implanted in the patient 14. Therefore, it should be understood that the illustrative treatment system described herein may include any suitable number of leads coupled to IMDs 16, 716, 814, and each of these leads may extend to any location within or near the heart 12. For example, the illustrative treatment system may include locations such as... Figures 2A to 2C and Figure 4A The three transvenous leads shown are located as shown in Figures 3A to 3B. A single transvenous lead or its location is shown in Figures 3A to 3B. Figure 2D and 4B The two transvenous leads are shown.

[0061] Figure 5 This is a functional block diagram of an example configuration for IMD 16. Although according to Figures 2A to 2D The system shown is used to describe Figure 5 The IMD 16, but it should be understood that IMD 716, 814 may be substantially similar to IMD 16, and therefore IMD 716, 814 may include any or all of the functions described in the functional block diagram of IMD 16.

[0062] The IMD 16 includes a processor 80, a memory 82, a stimulation generator 84 (e.g., an electrical pulse generator or signal generation circuit), a sensing module 86 (e.g., a sensing circuit), a telemetry module 88, and a power supply 90. One or more components of the IMD 16, such as the processor 80, may be housed within a housing of the IMD 16 (e.g., within a pacemaker housing). The telemetry module 88, the sensing module 86, or both may be included in a communication interface. The memory 82 includes computer-readable instructions that, when executed by the processor 80, cause the IMD 16 and the processor 80 to perform various functions attributed to the IMD 16 and the processor 80 herein. The memory 82 may include any volatile, non-volatile, magnetic, optical, or electrical medium, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, or any other digital medium.

[0063] Processor 80 may include any one or more of the following: microprocessor, controller, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or equivalent discrete or integrated logic circuitry. In some examples, processor 80 may include multiple components (such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, or one or more FPGAs) and other discrete or integrated logic circuitry. The functionality of processor 80 attributable to this document may be embodied in software, firmware, hardware, or any combination thereof. Processor 80 controls stimulation generator 84 to select a treatment mode (e.g., selecting one or more of suppression pacing mode, ventricular fusion pacing mode, atrioventricular synchronous pacing mode, atrial fibrillation pacing mode, etc.) and delivers stimulation therapy to heart 12 according to the selected pacing mode and various senses (e.g., atrial depolarization or activation, ventricular atrial depolarization or activation, heart rate, P-wave to R-wave interval, etc.) that may be stored in memory 82. Specifically, the processor 80 can control the stimulation generator 84 to deliver electrical pulses having amplitude, pulse width, frequency, or electrode polarity specified by one or more selected treatment procedures and treatment modes.

[0064] In some embodiments, lead 23 may be operatively coupled to electrode 61 for monitoring or pacing the right atrium. Stimulation generator 84 may be electrically coupled to electrodes 40, 42, 44, 46, 48, 50, 58, 61, 62, 64, and 66, for example, via conductors of the respective leads 18, 20, 23 or, in the case of housing electrodes 58, via electrical conductors disposed within the housing 60 of IMD 16. Stimulation generator 84 may be configured to generate and deliver electrical stimulation therapy to the heart 12. For example, stimulation generator 84 may deliver a defibrillation shock to the heart 12 via at least two of electrodes 58, 62, 64, 66. Stimulation generator 84 may deliver pacing pulses via ring electrodes 40, 44, 48 respectively coupled to leads 18, 20, 23 and / or via helical electrodes 42, 46, 50 respectively connected to leads 18, 20, or 23. Cardiac conduction system pacing therapy can be delivered via cardiac conduction system leads 23 connected to the atrium, right ventricle, or left ventricle connection port of connector block 34. In some embodiments, cardiac conduction system pacing therapy can be delivered via leads 18 and / or 23. In some examples, the stimulation generator 84 delivers pacing, cardioversion, or defibrillation stimulation in the form of electrical pulses. In other examples, the stimulation generator 84 can deliver one or more of these types of stimulation in the form of other signals, such as sine waves, square waves, or other substantially continuous time signals.

[0065] The stimulation generator 84 may include a switching module, and the processor 80 may use the switching module to select, for example via a data / address bus, which of the available electrodes is used to deliver a defibrillation shock or pacing pulse. The switching module may include a switch array, a switch matrix, a multiplexer, or any other type of switching device suitable for selectively coupling stimulation energy to the selected electrode.

[0066] Sensing module 86 monitors signals from at least one of electrodes 40, 42, 44, 46, 48, 50, 58, 61, 62, 64, or 66 to monitor the electrical activity of heart 12, such as via electrocardiogram (ECG) signals and / or electrogram (EGM). Sensing module 86 may also include a switching module for selecting which of the available electrodes to use for sensing cardiac activity. In some examples, processor 80 may select the electrode acting as a sensing electrode via the switching module within sensing module 86, for example, by providing a signal via a data / address bus. In some examples, sensing module 86 includes one or more sensing channels, each of which may include an amplifier. In response to a signal from processor 80, the switching module may couple the output from the selected electrode to one of the sensing channels.

[0067] In some examples, one channel of the sensing module 86 may include an R-wave amplifier that receives signals from electrodes 44, 46 for pacing and sensing in the left ventricle 32 near the heart 12. Another channel may include another R-wave amplifier that receives signals from electrodes 40, 42 for pacing and sensing in the right ventricle 28 of the heart 12. In some examples, the R-wave amplifier may take the form of an automatic gain control amplifier that provides an adjustable sensing threshold based on the measured R-wave amplitude of the heart rhythm.

[0068] Additionally, in some examples, one channel of the sensing module 86 may include a P-wave amplifier that receives signals from electrodes 48, 50 used for pacing and sensing in the right atrium 26 of the heart 12. In some examples, the P-wave amplifier may take the form of an automatic gain control amplifier that provides an adjustable sensing threshold based on the amplitude of the P wave in the measured heart rhythm. Examples of R-wave amplifiers and P-wave amplifiers are described in U.S. Patent No. 5,117,824, entitled “APPARATUS FORMONITORING ELECTRICAL PHYSIOLOGIC SIGNALS,” issued June 2, 1992, to Keimel et al., the entire contents of which are incorporated herein by reference. Other amplifiers may also be used. In addition, in some examples, one or more sensing channels of sensing module 86 may be selectively coupled to housing electrode 58 or elongated electrode 62, 64 or 66 together with or in place of one or more electrodes 40, 42, 44, 46, 48 or 50, for example for unipolar sensing of R wave or P wave in any of the chambers 26, 28 or 32 of heart 12.

[0069] In some examples, the sensing module 86 includes a channel comprising an amplifier having a relatively wider passband than an R-wave amplifier or a P-wave amplifier, or a high-resolution amplifier having a relatively narrow passband for His bundle or bundle branch potential recording. Signals from selected sensing electrodes chosen for coupling to this broadband amplifier can be provided to a multiplexer and subsequently converted by an analog-to-digital converter into multi-bit digital signals for storage as an electrogram (EGM) in memory 82. In some examples, such storage of the EGM in memory 82 may be under the control of direct memory access circuitry. The processor 80 may employ digital signal analysis techniques to characterize the digitized signals stored in memory 82 to detect and classify the patient's heart rhythm from the electrical signals. The processor 80 may detect and classify the patient 14's heart rhythm by employing any of the numerous signal processing methods known in the art.

[0070] If the IMD 16 is configured to generate pacing pulses and deliver them to the heart 12, the processor 80 may include a pacemaker timing and control module, which may be embodied in hardware, firmware, software, or any combination thereof. The pacemaker timing and control module may include dedicated hardware circuitry (such as an ASIC) separate from other processor 80 components such as a microprocessor, or a software module executed by components of the processor 80 that may be a microprocessor or an ASIC. The pacemaker timing and control module may include a programmable counter that controls the basic time interval associated with DDD, VVI, DVI, VDD, AAI, DDI, DDDR, VVIR, DVIR, VDDR, AAIR, DDIR, and other single-chamber and dual-chamber pacing modes. In the aforementioned pacing modes, "D" may indicate dual-chamber, "V" may indicate ventricle, "I" may indicate suppression pacing (e.g., no pacing), and "A" may indicate atrium. The first letter in the pacing mode indicates the pacing chamber, the second letter indicates the chamber in which an electrical signal is sensed, and the third letter indicates the chamber in which a response to the sense is provided.

[0071] The intervals defined by the pacemaker timing and control module may include atrial and ventricular pacing escape intervals, refractory periods during which sensed P and R waves are ineffective for timing the restart of the escape interval, and the pulse width of the pacing pulse. As another example, the pacemaker timing and control module may define blanking periods and provide signals from sensing module 86 to blank one or more channels, such as amplifiers, for a period of time during and after the delivery of electrical stimulation to the heart 12. The duration of these intervals may be determined by processor 80 in response to data stored in memory 82. The pacemaker timing and control module may also determine the amplitude of the cardiac pacing pulse.

[0072] During pacing, the escape interval counter within the pacemaker timing / control module can be reset upon sensing R and P waves. The stimulation generator 84 may include pacemaker output circuitry, selectively coupled, for example, via a switching module to any combination of electrodes 40, 42, 44, 46, 48, 50, 58, 61, 62, or 66 suitable for delivering bipolar or monopolar pacing pulses to one of the chambers of the heart 12. The processor 80 can reset the escape interval counter when pacing pulses are generated by the stimulation generator 84, thereby controlling the basic timing of cardiac pacing functions, including anti-tachyarrhythmia pacing.

[0073] In some examples, processor 80 may operate as an interrupt-driven device and in response to an interrupt from the pacemaker timing and control module, wherein the interrupt may correspond to the occurrence of sensed P and R waves and the generation of cardiac pacing pulses. Any necessary mathematical calculations are performed by processor 80, and any updates to values ​​or intervals controlled by the pacemaker timing and control module of processor 80 may occur after such an interrupt. A portion of memory 82 may be configured to hold multiple recirculation buffers capable of holding a series of measured intervals that can be analyzed by processor 80 in response to the occurrence of a pacing or sensing interrupt to determine whether the patient's heart 12 is currently exhibiting an atrial or ventricular tachyarrhythmia.

[0074] Telemetry module 88 includes any suitable hardware, firmware, software, or any combination thereof for communicating with another device such as programmer 24. Under the control of processor 80, telemetry module 88 can receive downlink telemetry from programmer 24 and transmit uplink telemetry to programmer via an antenna that may be internal and / or external. Processor 80 can provide, for example, data to be transmitted uplink to programmer 24 and control signals for telemetry circuitry within telemetry module 88 via an address / data bus. In some examples, telemetry module 88 can provide received data to processor 80 via a multiplexer.

[0075] The various components of the IMD 16 are connected to a power source 90, which may include a rechargeable or non-rechargeable battery. A non-rechargeable battery may be selected to last for several years, while a rechargeable battery may be inductively charged from an external device, for example, on a daily or weekly basis.

[0076] The exemplary device and method described herein can provide adaptive cardiac conduction system pacing therapy. When used in conjunction with cardiac conduction system pacing therapy, this exemplary adaptive cardiac conduction system pacing therapy can provide the timing configuration for both cardiac conduction system pacing and conventional left ventricular pacing. Furthermore, this exemplary adaptive cardiac conduction system pacing therapy can also provide switching from cardiac conduction system pacing therapy alone to a combination of cardiac conduction system pacing therapy and conventional left ventricular pacing therapy.

[0077] ICDs have traditionally provided treatment for tachyarrhythmias and have evolved to require upgrades to biventricular pacing systems (CRT-D) for patients with worsening heart failure exhibiting asynchrony. ICDs with conduction system leads have the ability to deliver physiological pacing (e.g., left bundle area pacing) to the patient. This capability enhances the value of ICDs, which can be used not only as devices for tachyarrhythmias capable of providing heart rate and rhythm support but also as devices that can potentially resolve asynchrony due to underlying conduction system disease. The examples described herein can be used to resolve interventricular asynchrony. Interventricular asynchrony can be described as a lack of synchrony or difference in systolic timing between different ventricles of the heart (i.e., between the left and right ventricles). Significant differences in systolic timing can reduce cardiac efficiency.

[0078] ICD patients may develop worsening cardiac asynchrony over time and may therefore benefit from resynchronization pacing to resolve the asynchrony. Detecting asynchronic deterioration, especially in patients with typical atrioventricular interventricular phases, can be challenging. The implementation described in this article uses a metric from a phonocardiogram sensor that can be used to track asynchrony in ICD patients. Asynchrony identification can be used to initiate and / or maintain conduction system pacing therapy to correct the asynchrony.

[0079] Figure 6A and Figure 6B Example heart sound signal features that can be used to monitor asynchrony are illustrated. Heart signal 190 is labeled to show heart sounds S1-S4. Heart signal trace 180 is labeled to show the P wave, QRS complex, and T wave of the electrical signal. Figure 6A and Figure 6BSeveral acoustic electrocardiogram (ECG) measures are also illustrated. For example, the electromechanical activation time (EMAT) 192 can be approximated by the interval between the Q of signal 180 and the S1 of signal 190. The Q-S1 interval is a substitute for the maximum rate of change of LV blood pressure. Increasing the Q-S1 interval indicates a decrease in the maximum rate of change of pressure. In some examples, EMAT is normalized by the R-R interval, i.e., the R-R interval is used to remove changes based on the current heart rate. The S1-S2 interval is a substitute for stroke volume, i.e., left ventricular systolic time (LVST) 194. A decreased S1-S2 interval is equivalent to a decreased stroke volume. In some examples, LVST is normalized by the R-R interval. The preatrial filling time (PAFT) 196 is determined based on the interval between heart sound S2 and the P wave of the EGM (or ECG) signal. The accelerated atrial filling time (AAFT) 198 is determined based on the interval between the P wave of the EGM (or ECG) signal and heart sound S1. Furthermore, the presence of heart sounds S3 or S4 indicates left ventricular dysfunction. The intensity and pervasiveness of heart sounds S3 or S4 further indicate the degree of dysfunction present. One or more of the illustrated acoustic echocardiographic measures can be used to determine whether cardiac conduction system pacing therapy should be delivered.

[0080] Figure 7 The method for determining whether delivery is possible is shown. Figures 1 to 5 An exemplary method 700 for treatment using a conduction system employed by the device. One or more electrodes of the IMD are used to monitor the patient's heart sounds. For example, one or more of S1, S2, S3, and S4 may be monitored. According to various examples, the monitored heart sounds are used to determine the sound-on-ejection phase (HS-PEP). In some examples, determining HS-PEP involves tracking a baseline time interval from a ventricular sensing marker to the heart sound signal. A ventricular sensing marker may be generated when the device senses an electrical event on the ventricular sensing lead. For example, a ventricular sensing marker typically corresponds to localized activation of ventricular tissue in a given cardiac cycle. The baseline may include the peak value and / or steepest rectified slope of the heart sound signal, such as S1.

[0081] The IMD uses monitored heart sounds to detect cardiac asynchrony 720. The detected asynchrony can be used to determine the action to be taken based on the type and / or amplitude of the asynchrony. In some examples, the IMD determines whether cardiac asynchrony worsens over time. Worsening asynchrony can be determined based on the difference in HS-PEP over time. For example, if the difference in HS-PEP over a specified time period is greater than a predefined threshold, the IMD's processor can be used to determine whether conduction system therapy should be initiated. The difference in HS-PEP can be calculated over a specified time period and / or a rolling average can be calculated. In some examples, the IMD performs trend monitoring of HS-PEP over time. For example, HS-PEP trends can be monitored over hours, days, weeks, or months. The difference in HS-PEP over time can be based on a specified time period of trend data (e.g., seven days). For example, if HS-PEP gradually widens and exceeds the seven-day moving average, it may be an indicator of worsening asynchrony.

[0082] If the difference in HS-PEP over time is determined to be greater than or equal to a specified threshold, a deterioration in synchrony is detected 720, and cardiac conduction system therapy 730 is delivered to resolve the cardiac synchrony. For example, the IMD can be configured to initiate one or both of atrial synchronous left bundle branch (LBB) pacing and His pacing based on a change in HS-PEP greater than or equal to a specified threshold.

[0083] In some configurations, conduction system pacing can be delivered adaptively. For example, the IMD can be configured to determine and / or monitor the atrioventricular interventricular period (AV interval) value, and the IMD can be configured to adaptively deliver conduction system pacing at a specified percentage of the AV interval value. The specified percentage can be based on a magnitude of the difference between the HS and PEP values. In some examples, this percentage is in the range of approximately 0.50% to approximately 0.60% of the inherent AV interval value. For example, this percentage is approximately 0.56% of the inherent AV interval value.

[0084] Figure 8 The method for determining whether delivery is possible is shown. Figures 1 to 5 Another illustrative method of treatment using a conduction system is 800. One or more electrodes of the IMD are used to monitor the patient's HS-PEP 810.

[0085] IMD determines whether cardiac dyssynchrony worsens over time. For example, IMD determines whether the difference in HS-PEP over time exceeds a predefined threshold of 820. The difference can be calculated over a specified time period and / or a rolling average can be calculated. For example, a seven-day rolling average can be used to determine the difference in HS-PEP over time.

[0086] Similar to Figure 7In the example shown, if the HS-PEP difference is determined to be greater than a predefined threshold 820, cardiac conduction system therapy 830 is delivered to resolve cardiac asynchrony. If the change in HS-PEP is determined to be no greater than or equal to the predefined threshold 820, the IMD can continue to monitor for worsening asynchrony without delivering cardiac conduction system pacing.

[0087] Based on some examples, IMD can continue to determine HS-PEP during the delivery of conduction system pacing to determine whether asynchrony has been corrected.840 For example, it can be determined that asynchrony has been corrected by determining that the difference in HS-PEP over time has decreased below a predefined threshold.

[0088] If it is determined that the asynchrony has not been corrected 840, the IMD continues to deliver cardiac conduction therapy. If it is determined that the asynchrony has been corrected 840, the IMD terminates conduction therapy and continues to monitor HS-PEP 810 in an attempt to detect future cardiac asynchrony.

[0089] Various embodiments have been described. These and other embodiments are within the scope of the appended claims. For example, the exemplary methods described herein may be implemented using single-chamber, dual-chamber, or triple-chamber pacemakers (e.g., CRT-P) or ICD (e.g., CRT-D) devices.

[0090] Exemplary Examples

[0091] While this disclosure is not limited thereto, an understanding of various aspects of this disclosure will be obtained through discussion of the specific exemplary embodiments provided below. Various modifications to the exemplary embodiments and additional embodiments of this disclosure will become apparent herein.

[0092] Example 1: An implantable medical device comprising: a plurality of implantable electrodes for sensing and pacing a patient's heart, wherein the plurality of electrodes includes cardiac conduction system electrodes capable of being positioned close to a portion of the patient's cardiac conduction system; and a computing device including processing circuitry operatively coupled to the plurality of implantable electrodes, wherein the computing device is configured to: monitor the sound-heart-ejection pre-purge (HS-PEP) of the patient's heart; determine a change in the HS-PEP based on the monitoring; determine that the change in the HS-PEP is greater than or equal to the specified threshold; and, based on the HS-PEP being greater than or equal to the specified threshold, initiate cardiac conduction system pacing therapy delivered to the patient's cardiac conduction system using the cardiac conduction system electrodes.

[0093] Example 2: The implantable medical device according to Example 1, wherein the cardiac conduction system electrode is positioned close to the patient’s His bundle to deliver cardiac conduction system pacing therapy to the patient.

[0094] Example 3. An implantable medical device according to Example 1 or Example 2, wherein the cardiac conduction system electrode is positioned close to the left diaphragm of the patient's heart to deliver cardiac conduction system pacing therapy to it.

[0095] Example 4. An implantable medical device according to any one of Examples 1 to 3, wherein the cardiac conduction system electrode is positioned close to the patient's left bundle branch to deliver cardiac conduction system pacing therapy to the patient.

[0096] Example 5. An implantable medical device according to any one of Examples 1 to 4, wherein monitoring the HS-PEP includes: tracking a reference time interval from a ventricular sensing marker to a heart sound signal.

[0097] Example 6. The implantable medical device according to Example 5, wherein the reference includes one or more of the peak value of the heart sound signal and the steepest rectified slope.

[0098] Example 7. An implantable medical device according to any one of Examples 1 to 6, wherein the computing device is configured to: perform trend monitoring of the HS-PEP over time; and use the trend-monitored HS-PEP to determine that the change in the HS-PEP is greater than or equal to the specified threshold.

[0099] Example 8. An implantable medical device according to any one of Examples 1 to 7, wherein the computing system is configured to initiate one or both of left bundle branch (LBB) pacing and His pacing based on the change in the HS-PEP being greater than or equal to the specified threshold.

[0100] Example 9. An implantable medical device according to any one of Examples 1 to 8, wherein the computing device is configured to initiate adaptive delivery conduction system pacing at a specified percentage of the atrioventricular interventricular period value.

[0101] Example 10. An implantable medical device according to Example 9, wherein the specified percentage is based on the variation of the HS-PEP.

[0102] Example 11. An implantable medical device according to any one of Examples 1 to 10, wherein the computing device is configured to monitor the HS-PEP after initiating the delivery of cardiac conduction system pacing.

[0103] Example 12. An implantable medical device according to any one of Examples 1 to 11, wherein the change in HS-PEP being greater than or equal to the designated threshold indicates asynchronous deterioration of the heart, and the cardiac conduction system pacing is configured to correct the asynchrony.

[0104] Example 13. The implantable medical device according to Example 12, wherein the computing device is configured to: determine whether the asynchrony has been corrected after the delivery of cardiac conduction system pacing is initiated.

[0105] Example 14. The implantable medical device according to Example 13, wherein the computing device is configured to terminate the delivery of cardiac conduction system pacing based on determining that the asynchrony has been corrected.

[0106] Example 15. An implantable medical device according to any one of Examples 1 to 14, wherein the implantable medical device is an implantable defibrillator.

[0107] Example 16. An implantable defibrillator comprising: a plurality of implantable electrodes for sensing and pacing a patient's heart, wherein the plurality of electrodes includes: a coil electrode; and a conduction system electrode capable of being positioned close to a portion of the patient's cardiac conduction system; and a computing device including processing circuitry operatively coupled to the plurality of implantable electrodes, wherein the computing device is configured to: monitor the sound-of-heart ejection pre-ejection phase (HS-PEP) of the patient's heart; determine a change in the HS-PEP based on the monitoring; determine that the change in the HS-PEP is greater than or equal to the specified threshold; and, based on the HS-PEP being greater than or equal to the specified threshold, initiate cardiac conduction system pacing therapy delivered to the patient's cardiac conduction system using the cardiac conduction system electrodes.

[0108] Example 17. The implantable defibrillator according to Example 16, wherein the plurality of electrodes further includes a pacing sensing electrode that is capable of being located close to the atria of the patient's heart.

[0109] Example 18. An implantable defibrillator according to Example 16 or Example 17, wherein the cardiac conduction system electrode is positioned close to the patient’s His bundle to deliver cardiac conduction system pacing therapy to the patient.

[0110] Example 19. An implantable defibrillator according to any one of Examples 16 to 18, wherein the cardiac conduction system electrode is positioned close to the left diaphragm of the patient's heart to deliver cardiac conduction system pacing therapy thereto.

[0111] Example 20. A method comprising: monitoring the sound-heart ejection pre-ejection phase (HS-PEP) of a patient's heart; determining a change in the HS-PEP based on the monitoring; determining that the change in the HS-PEP is greater than or equal to the specified threshold; and initiating cardiac conduction system pacing therapy to the patient's cardiac conduction system based on the HS-PEP being greater than or equal to the specified threshold.

[0112] This disclosure has been provided with reference to exemplary embodiments and examples, and is not intended to be construed as limiting. As previously stated, those skilled in the art will recognize that various other exemplary applications can utilize the beneficial features of the apparatus and methods described herein using the techniques described herein. Various modifications to the exemplary embodiments and examples will become apparent upon reference to this specification.

[0113] In one or more examples, the described techniques may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functionality may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. The computer-readable medium may include a non-transitory computer-readable medium that corresponds to a tangible medium, such as a data storage medium (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that is accessible by a computer).

[0114] Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general-purpose microprocessors, application-specific integrated circuits (ASICs), field-programmable arrays (FPGAs), or other equivalent integrated or discrete logic circuit systems. Therefore, the term "processor" as used herein may refer to any of the foregoing structures or any other physical structures suitable for implementing the described techniques. Furthermore, these techniques may be fully implemented in one or more circuit or logic elements.

[0115] All references and publications cited herein are expressly incorporated in their entirety by way of citation for all purposes, unless in any way directly contradict this disclosure.

[0116] Unless otherwise stated, all scientific and technical terms used herein have the meanings commonly used in the art. The definitions provided herein are intended to facilitate understanding of certain terms frequently used herein and are not intended to limit the scope of this disclosure.

[0117] Unless otherwise specified, all numerical values ​​used in the specification and claims to indicate the size, quantity, and physical properties of features are to be understood as being modified by the terms “precisely” or “about”. Therefore, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and appended claims are approximate values ​​that may vary within the typical range of experimental error, based on the desired properties sought by those skilled in the art using the teachings disclosed herein.

[0118] The numerical range described by the endpoints includes all values ​​contained within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range. In this document, the terms "at most" or "not greater than" a value (e.g., at most 50) include that value (e.g., 50), and the terms "not less than" a value (e.g., not less than 5) include that value (e.g., 5).

[0119] The terms “link” or “connection” refer to components being directly attached to each other (in direct contact with each other) or indirectly attached to each other (having one or more components between and attached to two components). Both terms can be modified by the interchangeable terms “operationally” and “operationally” to describe a link or connection configured to allow components to interact to perform at least some functions (e.g., a mobile user device can be operationally linked to a cellular network to send data to or receive data from it).

[0120] References to “one embodiment,” “implementation,” “certain embodiments,” or “some embodiments,” etc., mean that a particular feature, configuration, composition, or characteristic described in connection with that embodiment is included in at least one embodiment of this disclosure. Therefore, the appearance of such phrases throughout the document does not necessarily refer to the same embodiment of this disclosure. Furthermore, specific features, configurations, compositions, or characteristics may be combined in any suitable manner in one or more embodiments.

[0121] As used in this specification and the appended claims, the singular forms “a” and “the” cover embodiments having multiple indicators, unless otherwise expressly stated. As used in this specification and the appended claims, the term “or” is used in its usual sense and includes “and / or”, unless otherwise expressly stated.

[0122] As used in this article, "having," "including," and "containing" are used in their open-ended sense and usually mean "including but not limited to." It should be understood that "basically composed of" and "composed of" are categorized under "containing."

[0123] The term “and / or” means one or all of the listed elements or a combination of at least two of the listed elements.

[0124] The phrases accompanying the list, such as “at least one of…”, “including at least one of…”, and “one or more of…”, refer to any one item in the list or any combination of two or more items in the list.

Claims

1. An implantable medical device, the implantable medical device comprising: Multiple implantable electrodes for sensing and pacing a patient's heart, wherein the multiple electrodes include cardiac conduction system electrodes that can be positioned close to a portion of the patient's cardiac conduction system; and A computing device, including processing circuitry, operatively connectable to the plurality of implanted electrodes, wherein the computing device is configured to: Monitor the patient's heart sounds during the pre-ejection phase (HS-PEP). The changes in the HS-PEP are determined based on the monitoring. Determine that the change in the HS-PEP is greater than or equal to a specified threshold; as well as Based on the HS-PEP being greater than or equal to the specified threshold, cardiac conduction system pacing therapy is initiated by using the cardiac conduction system electrodes to deliver cardiac conduction system pacing therapy to the patient's cardiac conduction system.

2. A method, the method comprising: Monitor the patient's heart sounds during the pre-ejection phase (HS-PEP). The changes in the HS-PEP are determined based on the monitoring. Determine that the change in the HS-PEP is greater than or equal to a specified threshold; as well as Based on the HS-PEP being greater than or equal to the specified threshold, cardiac conduction system pacing therapy is initiated and delivered to the patient's cardiac conduction system.

3. The implantable medical device of claim 1 or the method of claim 2, wherein the cardiac conduction system electrode is positioned close to the patient’s His bundle to deliver cardiac conduction system pacing therapy to the patient.

4. The implantable medical device of claim 1 or the method of claim 2, wherein the cardiac conduction system electrode is capable of being positioned within the interventricular septum via the right ventricle of the patient's heart to deliver cardiac conduction system pacing therapy thereto.

5. The implantable medical device of claim 1 or the method of claim 2, wherein the cardiac conduction system electrode is positioned close to the patient's left bundle branch to deliver cardiac conduction system pacing therapy thereto.

6. The implantable medical device of claim 1 or the method of claim 2, wherein monitoring the HS-PEP comprises: The time interval from ventricular sensing marker to heart sound signal is tracked as a reference, the reference including one or more of the peak value and steepest rectified slope of the heart sound signal.

7. The implantable medical device of claim 1 or the method of claim 2, wherein the computing device is configured to: The trend of the HS-PEP is monitored over time; and The trend-monitored HS-PEP is used to determine whether the change in the HS-PEP is greater than or equal to the specified threshold.

8. The implantable medical device of claim 1 or the method of claim 2, wherein the computing system is configured to initiate at least one of left bundle branch (LBB) pacing or His pacing based on the change in the HS-PEP being greater than or equal to the designated threshold.

9. The implantable medical device of claim 1 or the method of claim 2, wherein the computing device is configured to initiate adaptive delivery conduction system pacing at a specified percentage of the atrioventricular interventricular period value, the specified percentage being based on the variation of HS-PEP.

10. The implantable medical device of claim 1 or the method of claim 2, wherein the computing device is configured to monitor the HS-PEP after initiating delivery of cardiac conduction system pacing.

11. The implantable medical device of claim 1 or the method of claim 2, wherein the change in HS-PEP being greater than or equal to the designated threshold indicates asynchronous deterioration of the heart, and the cardiac conduction system pacing is configured to correct the asynchrony, wherein the computing device is configured to: Determine whether the asynchrony has been corrected after the initiation of cardiac conduction system pacing delivery; and The delivery of cardiac conduction system pacing is terminated based on the determination that the asynchrony has been corrected.

12. An implantable defibrillator, the implantable defibrillator comprising: Multiple implantable electrodes for sensing and pacing a patient's heart, wherein the multiple electrodes include: Coil electrodes; and Conducting system electrodes, the conducting system electrodes being positioned close to a portion of the patient's cardiac conduction system; and A computing device, including processing circuitry, operatively connectable to the plurality of implanted electrodes, wherein the computing device is configured to: Monitor the patient's heart sounds during the pre-ejection phase (HS-PEP). The changes in the HS-PEP are determined based on the monitoring. Determine that the change in the HS-PEP is greater than or equal to a specified threshold; and Based on the HS-PEP being greater than or equal to the specified threshold, cardiac conduction system pacing therapy is initiated by using the cardiac conduction system electrodes to deliver cardiac conduction system pacing therapy to the patient's cardiac conduction system.

13. The implantable defibrillator of claim 12, wherein the plurality of electrodes further comprises a pacing sensing electrode capable of being located close to the atria of the patient's heart.

14. The implantable defibrillator of claim 12 or 13, wherein the cardiac conduction system electrode is positioned close to the patient’s His bundle to deliver cardiac conduction system pacing therapy to the patient.

15. The implantable defibrillator according to any one of claims 12 to 14, wherein the cardiac conduction system electrode is positioned close to the left diaphragm of the patient's heart to deliver cardiac conduction system pacing therapy thereto.

Images