Transient cardiac resynchronization therapy

Abstract

Illustrative devices and methods may provide cardiac resynchronization therapy (CRT) that utilizes instantaneous CRT settings to mitigate right ventricular load during implementation of the CRT. The aggressiveness of the instantaneous CRT setting may be increased until the target CRT setting is reached. Further, the transient CRT setting may reduce aggressiveness in response to ventricular degradation.

Description

[0001] Related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 462,689, filed April 28, 2023, the entire contents of which are incorporated herein by reference.

[0003] This disclosure relates in general to, for example, the delivery of transient cardiac resynchronization therapy prior to the delivery of cardiac resynchronization therapy.

[0004] This allows for the evaluation of a patient's cardiac performance characteristics to provide individualized treatment using cardiac resynchronization therapy (CRT). The heart's beating is controlled by the sinoatrial node, a group of conduction cells located in the right atrium near the entrance to the superior vena cava. Depolarization signals generated by the sinoatrial node activate the atrioventricular node (AV node). The AV node briefly delays the propagation of the depolarization signal, allowing blood in the atria to drain into the ventricles before the depolarization signal is delivered to the heart. Coordinated contractions of the two ventricles drive blood flow through the patient's trunk. In some cases, the conduction of the depolarization signal from the AV node to the left and right ventricles may be interrupted or slowed. This can lead to asynchrony in the contractions of the left and right ventricles, and ultimately, heart failure or death.

[0005] CRT can correct symptoms of electrical asynchrony by providing pacing therapy to one or both ventricles or atria (e.g., by providing pacing to promote earlier activation of the left or right ventricle). The ventricles can be paced to control their contractions, resulting in synchronized ventricular contractions. Many patients who have undergone CRT have experienced increased ejection fraction, improved exercise capacity, and increased well-being.

[0006] Providing patients with CRT may involve determining whether a patient will benefit from CRT before implanting a pacemaker. Additionally, a detailed evaluation can help determine the optimal placement of one or more ventricular pacing leads or the optimal programming of device parameters, such as the selection of electrodes on multipolar right or left ventricular leads, and the timing of pacing pulses delivered to the electrodes (such as atrioventricular (AV) pacing delay and interventricular (VV) pacing delay).

[0007] The mechanism of action attributed to CRT can be described as its transient re- coordination effect on the electromechanical function of the left ventricle. With biventricular pacing, CRT can repair left ventricular mechanical dyssynchrony at least in part through interventricular and intraventricular resynchronization of cardiac electrical activation. When CRT is implemented for a patient, the right ventricle (RV) can not be taken into account. However, the loading conditions of either ventricle directly affect the function (e.g., pumping function) of the other ventricle. In addition, systolic dysfunction as well as diastolic dysfunction of the RV can be an independent predictor of non-response to CRT. Moreover, CRT can immediately increase the workload of the right ventricular muscle of a patient (e.g., a patient with heart failure and left bundle branch block). If the patient's right ventricular function is already compromised prior to therapy, CRT can overburden the RV and its function can further deteriorate, hindering any positive effect of CRT on the left ventricle (LV). SUMMARY

[0008] The present disclosure can be described as being capable of overcoming the "sudden" increase in RV workload and deterioration of LV function at the time of implementation or initiation of CRT for a patient by utilizing or providing a transient or adaptive CRT setting process that transiently modifies the CRT settings to the optimal settings determined by conventional CRT, such as, for example, adaptive CRT. For example, in one embodiment, the CRT settings can include adaptive atrioventricular and interventricular pacing intervals that start at a longer time than the normal applied AV pacing delay and gradually decrease / adjust the timing to the optimal timing. Further, for example, in one embodiment, the CRT settings can include multi-point ventricular pacing that can be gradually enabled. The use of transient CRT settings can allow right ventricular accommodation and contribute to overall performance, including LV performance that changes over time (e.g., a transition period, a CRT setting ramp period, etc.). The target or final CRT settings can be the same or similar to those currently applied for CRT, which has been shown to be associated with reduced morbidity and mortality. The target CRT settings can be determined automatically using the IMD and / or other operably coupled systems, by a physician, and / or provided via a network-connected system.

[0009] It can be described that the present disclosure generally relates to mitigating right ventricular load during implementation of CRT by delivering CRT to the heart of a patient according to transient CRT settings that are less aggressive than target CRT settings to partially optimize left ventricular functionality. In other words, CRT therapy can be delivered to a patient according to transient CRT settings (where the transient CRT settings are less aggressive than target CRT settings) to only partially optimize left ventricular functionality, thereby mitigating right ventricular load, and the transient CRT settings can transition to the target CRT settings over a transition period.

[0010] Additionally, the present disclosure can be described as providing CRT with transient CRT settings, such as transient atrioventricular and interventricular pacing intervals, in patients with right ventricular dysfunction. The transient CRT settings can transition to target CRT settings that optimize left ventricular functionality and restore mechanical synchrony of the patient's heart by electrically activating the heart in a synchronized manner.

[0011] In one or more embodiments, a transient or adaptive CRT setting process can be provided (e.g., only provided) to (e.g., only to) patients with concomitant RV dysfunction, e.g., as detected by echocardiogram, other imaging modalities, invasive hemodynamic evaluation, or electrocardiogram analysis. Additionally, in one or more embodiments, the transient or adaptive CRT setting process can be built into or on top of existing CRT timing processes, such as, for example, adaptive CRT (aCRT) or CRT efficacy enhancement (CRTEE). Further, it can be described that the transient or adaptive CRT setting process can be personalized, easy to implement, used without additional power consumption or battery usage, and increase CRT response rate. Still further, in one or more embodiments, the transient or adaptive CRT settings can be used in conjunction with cardiac conduction system pacing modalities, such as, for example, left bundle branch pacing therapy, right bundle branch pacing therapy, left ventricular septal pacing therapy, HIS bundle pacing therapy, and any combination of such therapies (e.g., left bundle branch optimized CRT and HIS optimized CRT), which can be important because cardiac conduction system pacing therapy can be more effective than traditional myocardial pacing therapy, resulting in greater ventricular workload shift than traditional myocardial pacing therapy.

[0012] Exemplary devices and methods can be described as including or utilizing a time adaptive CRT process to preserve RV functionality and increase CRT response. To this end, these devices and methods can include determining whether a patient is eligible for CRT (e.g., whether the patient would benefit from CRT therapy), assessing baseline RV functionality of the patient, determining whether the patient has RV dysfunction based on the assessment, and providing transient or time adaptive atrioventricular and / or interventricular pacing intervals. These devices and methods can include assessing baseline RV functionality of the patient after an assessment period, such as, for example, one or more weeks, determining whether the patient's RV dysfunction is better, worse, or non-existent, and adjusting the provided transient or time adaptive atrioventricular and / or interventricular pacing intervals based on whether the patient's RV dysfunction is better, worse, or non-existent.

[0013] An exemplary implantable medical device may include: an electrode device comprising one or more electrodes configured to deliver a CRT to a patient's heart using a cardiac resynchronization therapy (CRT) setting and to sense the electrical activity of the patient's heart; and a computing device operatively coupled to the electrode device and including processing circuitry. In one embodiment, the computing device may be configured to: provide a target CRT setting configured to optimize left ventricular function and restore the mechanical synchronicity of the heart by synchronously activating the patient's heart; and to reduce right ventricular load during CRT implementation by delivering a CRT to the patient's heart using the electrode device according to a less aggressive transient CRT setting to partially optimize left ventricular function. In one embodiment, the computing device may be configured to: deliver a CRT to the patient's heart using the electrode device according to a transient CRT setting less aggressive than the target CRT setting to partially optimize left ventricular function, thereby reducing right ventricular load and transitioning from the transient CRT setting to the target CRT setting during a transition period.

[0014] An exemplary method may include: delivering cardiac resynchronization therapy (CRT) to a patient's heart using one or more electrodes of an implantable medical device; providing a target CRT setting configured to optimize left ventricular function and restore the mechanical synchronicity of the heart by synchronously activating the patient's heart; and reducing right ventricular load during CRT implementation by delivering CRT to the patient's heart using the electrode device according to a transient CRT setting that is less aggressive than the target CRT setting to partially optimize left ventricular function.

[0015] An exemplary method may include: using the electrode device to deliver cardiac resynchronization therapy (CRT) to the patient's heart using one or more electrodes of an implantable medical device according to a transient CRT setting to the patient's heart, wherein the transient CRT setting is less aggressive than a target CRT setting to partially optimize left ventricular function, thereby reducing right ventricular load; and transitioning from the transient CRT setting to the target CRT setting during a transition period.

[0016] Details of one or more aspects of this disclosure are set forth in the following drawings and description. Other features, objects, and advantages of the technology described in this disclosure will be apparent from the description, drawings, and claims. Attached Figure Description

[0017] Figure 1 This is a diagram of an exemplary system that includes an implantable medical device (IMD) and a programmer.

[0018] Figure 2yes Figure 1 A diagram illustrating an example of an IMD.

[0019] Figure 3 yes Figures 1 to 2 A block diagram of the IMD.

[0020] Figure 4 yes Figure 1 A diagram of an exemplary programmer for the system.

[0021] Figure 5 It includes Figure 1 A diagram illustrating an exemplary system of an IMD and a programmer, as well as additional devices coupled to it via a network.

[0022] Figure 6 For example, using Figures 1 to 5 An exemplary method for systems and apparatus to reduce right ventricular load during CRT implementation.

[0023] Figure 7 It is a graph showing how the instantaneous CRT settings change over time. Detailed Implementation

[0024] The technology disclosed herein relates in general to reducing right ventricular load during the implementation of CRT delivered using an implantable medical device (IMD). This document relates to... Figures 1 to 7 Illustrative systems, apparatuses, methods, and processes are described for reducing right ventricular load during the implementation of CRT.

[0025] Figure 1 This is a conceptual diagram of an exemplary therapy system 10 that can be configured to deliver pacing therapies (such as cardiac pacing therapy and cardiac resynchronization therapy (CRT)) to a patient 14. Although the patient 14 is shown as a human, the patient 14 could also be a variety of other types of animals. The therapy system 10 may include an implantable medical device 16 (IMD) coupled to leads 18, 20, 22 and a programmer 24. The IMD 16 may be, for example, an implantable pacemaker, cardioverter-defibrillator, and / or a defibrillator that delivers or provides electrical signals (e.g., pacing, etc.) to the heart 12 of the patient 14 via electrodes coupled to one or more of leads 18, 20, 22, senses electrical signals from the heart 12 of the patient 14 via electrodes coupled to one or more of leads 18, 20, 22, and / or senses mechanical activity (e.g., sound, movement, vibration, etc.) of the heart 12 of the patient 14 via a mechanical cardiac activity sensor.

[0026] Leads 18, 20, and 22 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 1In the example shown, the right ventricle (RV) 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 ventricle (LV) coronary sinus lead 20 extends through one or more veins, the vena cava, and 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 right atrium (RA) lead 22 extends through one or more veins and the vena cava, and enters the right atrium 26 of the heart 12.

[0027] The IMD 16 can sense electrical signals associated with depolarization and repolarization of the heart 12 and sense mechanical cardiac activity signals of the heart 12 using a mechanical cardiac activity sensor, etc., via electrodes coupled to at least one of leads 18, 20, 22. In some examples, the IMD 16 provides pacing therapy (e.g., pacing pulses) to the heart 12 based on electrical signals sensed within the heart 12. The IMD 16 can be operable to adjust one or more parameters associated with pacing therapy, such as, for example, pacing rate, RR interval, AV pacing interval (or delay), VV pacing interval (or delay), and various other timing, pulse width, amplitude, voltage, burst length, etc. Furthermore, the IMD 16 can be operable to deliver pacing therapy using various electrode configurations, which can be monopolar, bipolar, quadrupole, or further multipolar. Thus, a multipolar lead system can provide or supply multiple electrical vectors for pacing from it. The pacing vector may include at least one cathode and at least one anode, the at least one cathode being at least one electrode located on at least one lead, and the at least one anode being at least one electrode located on at least one lead (e.g., the same lead or different leads) and / or on the housing or casing of the IMD or electrode device. While improvements in cardiac function as a result of pacing therapy may depend primarily on the cathode, electrical parameters such as impedance, pacing threshold voltage, current consumption, and lifespan may be more dependent on the pacing vector, which includes both the cathode and anode. The IMD 16 may also deliver defibrillation therapy and / or cardioversion therapy via an electrode located on at least one of leads 18, 20, 22. Further, the IMD 16 may detect arrhythmias of heart 12, such as fibrillation of ventricles 28, 32, and deliver defibrillation therapy to heart 12 in the form of electrical pulses. In some examples, the IMD 16 may be programmed to deliver a therapy process, e.g., pulses with increasing energy levels, until the fibrillation of heart 12 ceases.

[0028] In some examples, programmer 24 may be a mobile computing device (such as a smartphone) or a computer workstation. Programmer 24 may include a user interface that receives input from a user. The user interface may include, for example, a keypad and a display, which may be, for example, 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. 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 programmer 24 may include a touchscreen display, through which the user can interact with programmer 24.

[0029] Users such as physicians, technicians, patients, or other users can interact with programmer 24 to communicate with IMD 16. For example, a user can interact with programmer 24 to retrieve physiological or diagnostic information from IMD 16. Users can also interact with programmer 24 to program IMD 16, for example, by selecting values ​​for the IMD's operating parameters.

[0030] Furthermore, for example, the user can use programmer 24 to retrieve information from IMD 16 regarding other sensed physiological or diagnostic parameters of the patient 14, such as, for example, right ventricular dysfunction, left ventricular dysfunction, intracardiac or intravascular pressure, activity, posture, respiration, or thoracic impedance. As another example, the user can use programmer 24 to retrieve information from IMD 16 regarding the performance or integrity of IMD 16 or other components of system 10, such as leads 18, 20, and 22, or the power supply to IMD 16.

[0031] Users can use programmer 24 to view information from IMD 16. In some examples, users can activate features of IMD 16 by entering a single command via programmer 24, such as pressing a single key or combination of keys on the keypad or making a single-point selection action using a pointing device.

[0032] The 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 the IMD 16 and programmer 24.

[0033] Figure 2 yes Figure 1A more detailed conceptual diagram of the IMD 16 and leads 18, 20, 22 of the therapy system 10 is provided. Leads 18, 20, 22 may be electrically coupled via connector block 34 to a therapy delivery module (e.g., for delivering a CRT), a sensing module (e.g., for sensing one or more signals from one or more electrodes), and / or any other module of the IMD 16. In some examples, the proximal ends of leads 18, 20, 22 may include electrical contacts electrically coupled to corresponding electrical contacts within connector block 34 of the IMD 16. Furthermore, in some examples, leads 18, 20, 22 may be mechanically coupled to connector block 34 by means of a retaining screw, connecting pin, or other suitable mechanical coupling mechanism.

[0034] Each of leads 18, 20, and 22 includes an elongated insulated lead body capable of carrying multiple conductors (e.g., concentric coil conductors, straight conductors, etc.) separated from each other by insulation (e.g., a tubular insulating sheath). In the illustrated example, bipolar electrodes 40 and 42 are located near the distal end of lead 18. Furthermore, bipolar electrodes 44, 45, 46, and 47 are located near the distal end of lead 20, and bipolar electrodes 48 and 50 are located near the distal end of lead 22.

[0035] Electrodes 40, 44, 45, 46, 47, and 48 may be in the form of or defined as ring electrodes, and electrodes 42 and 50 may be in the form of or defined as extendable spiral-tipped electrodes retractably mounted within insulated electrode heads 52, 54, and 56. Each of electrodes 40, 42, 44, 45, 46, 47, 48, and 50 may be electrically coupled to a corresponding conductor (e.g., a coil conductor and / or a straight conductor) within the lead body of its associated leads 18, 20, and 22, and thereby coupled to a corresponding electrical contact at the proximal end of leads 18, 20, and 22.

[0036] Electrodes 40, 42, 44, 45, 46, 47, 48, and 50 can be further used to sense electrical signals (e.g., morphological waveforms within an electrogram (EGM)) accompanying depolarization and repolarization of the heart 12. The electrical signals are conducted to the IMD 16 via corresponding leads 18, 20, and 22. In some examples, the IMD 16 can also deliver pacing pulses via electrodes 40, 42, 44, 45, 46, 47, 48, and 50 to induce depolarization of the cardiac tissue of the patient's heart 12. In some examples, such as... Figure 2As illustrated, the IMD 16 includes 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 housing 60 (e.g., an hermetically sealed housing) of the IMD 16. Any of electrodes 40, 42, 44, 45, 46, 47, 48, and 50 may be combined with housing electrode 58 for unipolar sensing or pacing. It will be understood by those skilled in the art that other electrodes may also be selected to define or be used for pacing and sensing vectors. Further, any of electrodes 40, 42, 44, 45, 46, 47, 48, 50, and 58 may be used to sense electrical activity during pacing therapy when not being used for delivering pacing therapy.

[0037] For reference Figure 2 In further detail, the housing 60 may encapsulate a therapy delivery module, which may include a stimulation generator for generating cardiac pacing pulses and defibrillation or cardioversion shocks, and a sensing module for monitoring electrical signals of the patient's heart (e.g., the patient's heart rhythm). Leads 18, 20, and 22 may also include elongated electrodes 62, 64, and 66, respectively, which may be in the form of coils. The IMD 16 may deliver defibrillation shocks 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 may also be used to deliver cardioversion pulses to the heart 12. Furthermore, electrodes 62, 64, and 66 may be made of any suitable conductive material, such as, but not limited to, platinum, platinum alloys, and / or other materials known to be suitable for use in implantable defibrillation electrodes. Since electrodes 62, 64, and 66 are not typically configured for delivering pacing therapy, any of electrodes 62, 64, and 66 can be used to sense electrical activity and can be used in combination with any of electrodes 40, 42, 44, 45, 46, 47, 48, 50, and 58. In at least one embodiment, the RV elongated electrode 62 can be used to sense the electrical activity of a patient's heart during pacing therapy delivery (e.g., in combination with the housing electrode 58 or a defibrillator electrode-to-housing electrode vector).

[0038] The configuration of the therapy system 10 described above is merely an example. In other examples, the therapy system may include epicardial leads and / or patch electrodes to replace or supplement it. Figure 1 The transvenous leads 18, 20, and 22 are shown in the diagram. In another embodiment, the therapy system 10 may have a lead implanted in the left venous chamber of the heart in the absence of a transvenous lead (e.g., a leadless / wireless pacing system) or in the presence of a lead implanted (e.g., transvenous implantation or implantation using a method of implantation) (as a countermeasure). Figure 1In cases where the illustrated transvenous lead is placed in the right venous chamber of the heart, it may be implanted in / around the cardiac septum. Further, in one or more embodiments, the IMD 16 may not be implanted in the patient 14. For example, the IMD 16 may deliver various cardiac therapies to the heart 12 via a percutaneous lead that extends through the skin of the patient 14 to multiple locations within or outside the heart 12. In one or more embodiments, the system 10 may utilize wireless pacing (e.g., energy transfer to the pacing component within the heart via ultrasound, inductive coupling, RF, etc.) and sensing cardiac activation using electrodes on the housing / shell and / or subcutaneous leads.

[0039] Other example therapeutic systems that provide electrical stimulation to the heart 12 may include any suitable number of leads coupled to the IMD 16, and each of these leads may extend to any location within or near the heart 12. Such other therapeutic systems may include, for example... Figures 1 to 2 The illustrated three transvenous leads are positioned as shown. Further, the therapy system may include a single lead extending from IMD 16 into the right atrium 26, or two leads extending into the corresponding atrium in the right and left atria. In one example, IMD 16, as a cardiac resynchronization therapy (CRT) device with a left ventricular (LV) lead, may be useful for patients with HFpEF in the presence of complete AV node block, as the LV lead may be more beneficial than the RV lead in such patients.

[0040] Figure 3 This is a functional block diagram illustrating an exemplary configuration of IMD 16. As shown, IMD 16 may include a control module 81, a therapy delivery module 84 (e.g., which may include a stimulation generator), a sensing module 86, and a power supply 90. The control module or device 81 may include a computing device 80, a memory 82, and a telemetry module or device 88. The memory 82 may include computer-readable instructions that, when executed, for example by the computing device 80, cause the IMD 16 and / or the control module 81 to perform various functions belonging to the IMD 16 and / or the control module 81 described herein. Further, the memory 82 may include any volatile, non-volatile, magnetic, optical, and / or electrical media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, and / or any other digital media.

[0041] The computing device 80 of the control module 81 may include any one or more of the following: a microprocessor, a controller, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), and / or equivalent discrete or integrated logic circuitry. In some examples, the computing device 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, and / or one or more FPGAs, as well as other discrete or integrated logic circuitry. The functionality of the computing device 80 as defined herein may be embodied in software, firmware, hardware, or any combination thereof.

[0042] Control module 81 may be configured to perform one or more methods and processes described herein, including assessment or determination of RV and / or LV dysfunction, determination or generation of target CRT settings, determination or generation of transient CRT settings, implantation of transient CRT settings, and aggressiveness in changing (e.g., increasing or decreasing) transient CRT settings over time or in response to RV and / or LV dysfunction. Further, control module 81 may control the therapy delivery module or device 84 to deliver therapy (e.g., cardiac resynchronization therapy, adaptive pacing, bradycardia pacing) to heart 12 based on one or more selected therapy programs that may be stored in memory 82 and on algorithms or methods further described below. More specifically, the control module 81 (e.g., computing device 80) can control various parameters of the electrical stimulation delivered by the therapy delivery module 84, such as, for example, AV pacing interval (or delay), VV pacing interval (or delay), pacing pulse with amplitude, pulse width, frequency, or electrode polarity, which can be specified by one or more selected therapy programs (e.g., adaptive pacing therapy program, instantaneous CRT setting, target CRT setting, adjustment and / or modification program, pacing therapy program, pacing recovery program, capture management program, etc.). As shown, the therapy delivery module 84 is electrically coupled to electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66, for example, via conductors of the corresponding leads 18, 20, 22 or, in the case of housing electrodes 58, via electrical conductors disposed within the housing 60 of the IMD 16. The therapy delivery module 84 can be configured to generate an electrical stimulation therapy, such as pacing therapy, using one or more of electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66 and deliver the electrical stimulation therapy to the heart 12.

[0043] For example, the therapy delivery module 84 may deliver pacing stimulation (e.g., pacing pulses) via ring electrodes 40, 44, 45, 46, 47, 48 and / or helical tip electrodes 42, 50 of leads 18, 22. Further, for example, the therapy delivery module 84 may deliver a defibrillation shock to the heart 12 via at least two of electrodes 58, 62, 64, 66. In some examples, the therapy delivery module 84 may be configured to deliver pacing, cardioversion, or defibrillation stimulation in the form of electrical pulses. In other examples, the therapy delivery module 84 may be configured to deliver one or more of these types of stimulation in the form of other signals such as sine waves, square waves, and / or other substantially continuous time signals.

[0044] The IMD 16 may further include a switching module or device 85, and the control module 81 (e.g., computing device 80) may use the switching module 85 to select, for example via a data / address bus, which of the available electrodes are used for delivering therapy, such as pacing pulses for pacing therapy, or which of the available electrodes are used for sensing. The switching module 85 may include a switching array, a switching matrix, a multiplexer, or any other type of switching device suitable for selectively coupling the sensing module or device 86 and / or the therapy delivery module 84 to one or more selected electrodes. More specifically, the therapy delivery module 84 may include a plurality of pacing output circuits. Each of these plurality of pacing output circuits may, for example, be selectively coupled using the switching module 85 to one or more electrodes of electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66 (e.g., a pair of electrodes for delivering therapy to a bipolar or multipolar pacing vector). In other words, each electrode can be selectively coupled to one of the pacing output circuits of the therapy delivery module using the switching module 85.

[0045] The sensing module 86 is coupled (e.g., electrically coupled) to a sensing device, which, in addition to an additional sensing device, may include electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66 to monitor the electrical activity of the heart 12, such as electrocardiogram (ECG) / electrogram (EGM) signals. ECG / EGM signals can be used to measure or monitor activation time (e.g., ventricular activation time), heart rate (HR), heart rate variability (HRV), heart rate oscillation (HRT), deceleration / acceleration capacity, deceleration sequence morbidity, T wave alternation (TWA), P wave to P wave interval (also known as PP interval or AA interval), R wave to R wave interval (also known as RR interval or VV interval), P wave to QRS complex interval (also known as PR interval, AV interval or PQ interval), QRS complex morphology, QRS complex interval or QRS duration, ST segment (i.e., the segment connecting the QRS complex and the T wave), T wave changes, QT interval, electrical vectors, etc.

[0046] The sensing module 86 may also include a mechanical cardiac activity sensor 92 configured to monitor the mechanical activity of the patient's heart 12. The mechanical activity of the patient's heart may include or represent one or more movements, motions, sounds, and vibrations of the patient's heart 12 and one or more parts or anatomical structures of the patient's heart 12. For example, the mechanical cardiac activity sensor 92 may be configured to monitor mechanical activities corresponding to or indicating the closure of the atrioventricular valves (i.e., the mitral and tricuspid valves), the closure of the semilunar valves (i.e., the aortic and pulmonary valves), chamber filling, chamber contraction, and the transition from rapid filling to slow filling.

[0047] It should be understood that although the mechanical heart activity sensor 92 is depicted as part of the sensing module 86 within the housing 60 of the IMD 16, the mechanical heart activity sensor 92 may be external to the housing 60, either as part of or included therein, such as leads 18, 20, 22, and may be positioned at various locations within or around the patient's heart 12. Further, in at least one embodiment, the IMD 16 may be a leadless IMD including the mechanical heart activity sensor 92 and may be positioned within the chamber of the patient's heart 12, thereby placing the mechanical heart activity sensor 92 within the chamber of the patient's heart 12.

[0048] The switching module 85 can also be used with the sensing module 86 to select which of the available electrodes are used or enabled to, for example, sense the electrical activity of a patient's heart (e.g., using one or more electrical vectors of a patient's heart using any combination of electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66). Similarly, the switching module 85 can also be used with the sensing module 86 to select which of the available electrodes are not used (e.g., disabled) to, for example, sense the electrical activity of a patient's heart (e.g., using one or more electrical vectors of a patient's heart using any combination of electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66), etc. In some examples, the control module 81 may select the electrodes that act as sensing electrodes via a switching module within the sensing module 86, for example, by providing signals via a data / address bus.

[0049] In some examples, the sensing module 86 includes a channel comprising an amplifier having a relatively wider passband than an R-wave or P-wave amplifier. Signals from selected sensing electrodes can be supplied to a multiplexer and subsequently converted by an analog-to-digital converter into multi-bit digital signals for storage in memory 82, for example, as an electrogram (EGM). In some examples, such storage of an EGM in memory 82 can be under the control of direct memory access circuitry.

[0050] In some examples, the control module 81 may operate as an interrupt-driven device and may respond to an interrupt from the pacemaker timing and control module, where the interrupt may correspond to the occurrence of sensed P and R waves and the generation of cardiac pacing pulses. Any mathematical calculations may be performed by the computing device 80, and any updates to values ​​or intervals controlled by the pacemaker timing and control module may be performed or occur after such an interrupt. A portion of the memory 82 may be configured as a plurality of recirculation buffers capable of holding one or more series of measurement intervals that may be analyzed by, for example, the computing device 80 in response to the occurrence of a pacing or sensing interruption to determine whether the patient's heart 12 is currently exhibiting atrial or ventricular tachyarrhythmias.

[0051] The computing device 80 of the IMD 16 can be configured to evaluate or assess RV and / or LV dysfunction by monitoring one or more cardiac metrics indicative of right ventricular and / or left ventricular function. For example, QRS duration can be monitored, which can be used to determine RV dysfunction. Further, the computing device 80 of the IMD 16 can detect tachyarrhythmic episodes, such as ventricular fibrillation, ventricular tachycardia, rapid ventricular tachyarrhythmia episodes, or NST episodes, based on electrocardiographic activity of the heart 12 monitored via the sensing module 86. For example, at electrodes 40, 42, 44, 46, 48, 50, 58, 62, 64, and 66 (in... Figures 1 to 2 With the aid of at least some of the electrodes shown in the diagram, the sensing module 86 can generate an electrocardiogram (ECG) or electrogram (EGM) signal indicating electrocardiographic activity. Alternatively, the sensing module 86 can be coupled to a sensing electrode separate from the stimulating electrode that delivers electrical stimulation to the heart 12. Figures 1 to 2 (as shown in the diagram), and can be coupled to one or more leads different from leads 18, 20, and 22 (as shown in the diagram), Figures 1 to 2 (As shown in the image). ECG signals can indicate the depolarization of the heart 12.

[0052] For example, as previously described, in some examples, processor 80 identifies the presence of a tachyarrhythmia episode by detecting a threshold number of tachyarrhythmic events (e.g., RR or PP intervals with a duration less than or equal to the threshold). In some examples, computing device 80 may also identify the presence of a tachyarrhythmia episode by detecting variable coupling intervals between R waves of cardiac signals.

[0053] The telemetry module 88 of the control module 81 may include any suitable hardware, firmware, software, or any combination thereof for communicating with another device, such as a programmer (e.g., a mobile computing device or smartphone). For example, under the control of the computing device 80, the telemetry module 88 may receive downlink telemetry from the programmer or mobile computing device and transmit uplink telemetry to it via an antenna (which may be internal and / or external). The computing device 80 may provide, for example, data to be transmitted uplink to the programmer or mobile computing device and control signals for the telemetry circuitry within the telemetry module 88 via an address / data bus. In some examples, the telemetry module 88 may provide the received data to the computing device 80 via a multiplexer.

[0054] The various components of the IMD 16 are further coupled 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.

[0055] Figure 4This is a block diagram of the exemplary programmer 24. (Example:) Figure 4 As shown, the programmer 24 includes a processor 100, a memory 102, a user interface 104, a telemetry module 106, and a power supply 108. The programmer 24 can be a dedicated hardware device with dedicated software for programming the IMD 16. Alternatively, the programmer 24 can be an off-the-shelf computing device (e.g., a mobile computing device such as a smartphone) running an application that enables the programmer 24 to program the IMD 16.

[0056] Users can use programmer 24 to display and view assessments or metrics related to RV and / or LV dysfunction of the patient's heart, transient CRT settings, and target CRT settings. Additionally, users can use programmer 24 to select CRT settings (such as, for example, transient CRT settings and target CRT settings), increase or decrease the aggressiveness of CRT settings, select therapy procedures (e.g., stimulation parameter sets), generate new therapy procedures, modify therapy procedures through individual or global adjustments, or transfer new procedures to medical devices (such as...). Figure 1 (IMD 16). The user can interact with the programmer 24 via the user interface 104, which may include a display that presents a graphical user interface to the user, and a keypad or other mechanism for receiving input from the user.

[0057] Processor 100 may take the form of one or more microprocessors, DSPs, ASICs, FPGAs, programmable logic circuits, etc., and the functionality attributed to processor 100 herein may be embodied in hardware, firmware, software, or any combination thereof. Memory 102 may store instructions that enable processor 100 to provide the functionality attributed herein to programmer 24, as well as information used by processor 100 to provide the functionality attributed herein to programmer 24. Memory 102 may include any fixed or removable magnetic, optical, or electrical medium, such as RAM, ROM, CD-ROM, hard disk or floppy disk, or EEPROM, etc. Memory 102 may also include a removable memory portion that can be used to provide memory updates or increases in memory capacity. The removable memory may also allow easy transfer of IMD and / or patient data to another computing device, or to be removed before programmer 24 is used to program therapy for another patient. Memory 102 may also store information such as stimulation parameter values ​​that control therapy delivery via IMD 16.

[0058] The programmer 24 can communicate wirelessly with the IMD 16, such as using RF communication or near-end sensing interaction. This wireless communication is possible using a telemetry module 106 that can be coupled to an internal or external antenna. The external antenna coupled to the programmer 24 may correspond to a programming head that can be placed on the IMD 12, as referenced above. Figure 1As described. The telemetry module 106 can be similar to Figure 3 The telemetry module 88 of the IMD 16.

[0059] The telemetry module 106 can also be configured to communicate with another computing device via wireless communication technology or directly with another computing device via a wired connection. Examples of local wireless communication technologies that can be used to facilitate communication between the programmer 24 and another computing device include RF communication according to the 802.11 or Bluetooth specification set, and infrared communication according to, for example, the IrDA standard or other standards or proprietary telemetry protocols. In this way, other external devices can be able to communicate with the programmer 24 without establishing a secure wireless connection.

[0060] Power supply 108 delivers operating power to components of programmer 24 and may include a battery and power generation circuitry to generate operating power. In some embodiments, the battery may be rechargeable to allow for extended operation. Recharging can be achieved by electrically coupling power supply 108 to a bracket or plug connected to an AC outlet. Alternatively, recharging can be achieved via near-side inductive interaction between an external charger and an inductive charging coil within programmer 24. In other embodiments, conventional batteries (e.g., nickel-cadmium or lithium-ion batteries) may be used. Furthermore, programmer 24 may be directly coupled to an AC outlet to power itself. Power supply 108 may include circuitry for monitoring the remaining charge in the battery. In this way, user interface 104 can provide a current battery charge indicator or a low battery charge indicator when the battery needs to be replaced or recharged. In some cases, power supply 108 may be able to estimate the remaining operating time using the current battery.

[0061] Figure 5 This is a block diagram illustrating a system 190 according to one embodiment, the system including external devices 192 (such as a server), and connected via a network 196 to... Figures 1 to 4 One or more computing devices 194a to 194n, including the IMD 16 and programmer 24, are shown. In this embodiment, the IMD 16 can communicate with the programmer 24 via a first wireless connection using its telemetry module 88, and with the access point 198 via a second wireless connection. Figure 5In the example, access point 198, programmer 24, external device 192, and computing devices 194a to 194n are interconnected via network 196 and are able to communicate with each other. In some cases, one or more of access point 198, programmer 24, external device 192, and computing devices 194a to 194n may be coupled to network 196 via one or more wireless connections. IMD 16, programmer 24, external device 192, and computing devices 194a to 194n may each include or contain one or more processors capable of performing various functions and operations (such as those described herein), such as one or more microprocessors, DSPs, ASICs, FPGAs, or programmable logic circuits.

[0062] Access point 198 may include or contain a device connected to network 196 via any of a variety of connections, such as cellular data connection, dial-up telephone, digital subscriber line (DSL), or cable modem connection. In other examples, access point 198 may be coupled to network 196 via different forms of connection, including wired or wireless connection. In some examples, access point 198 may communicate with programmer 24 and / or IMD 16. Access point 198 may be located in conjunction with patient 14 (e.g., in the same room or location as patient 14) or remotely from patient 14. For example, access point 198 may be a home monitor located in the patient's home or easily carried by patient 14.

[0063] During operation, the IMD 16 can collect, measure, and store various forms of diagnostic data, such as RV dysfunction data (including systolic and diastolic dysfunction), LV dysfunction data (including systolic and diastolic dysfunction), QRS duration, and one or more diagnostic parameters that can be utilized by exemplary systems, methods, and processes. In some cases, the IMD 16 can directly analyze the collected diagnostic data and generate any corresponding reports or alarms. However, in other cases, the IMD 16 can wirelessly or via access point 198 and network 196 transmit diagnostic data (such as diagnostic parameters) to programmer 24, access point 198, and / or external device 192 for remote processing and analysis (e.g., to assess or determine RV or LV dysfunction).

[0064] In another example, IMD 16 may provide collected diagnostic data or parameters, such as RV dysfunction data, LV dysfunction data, QRS duration, and one or more diagnostic parameters, as well as target CRT settings and transient CRT settings, to external device 192 via access point 198 and network 196. External device 192 includes one or more processors 200. In some cases, external device 192 may request such data, and in other cases, IMD 16 may provide such data to external device 192 automatically or periodically. Upon receiving diagnostic data via input / output device 202, external device 192 may be able to analyze the data and generate reports, alarms, or other values.

[0065] One or more of the computing devices 194a to 194n can access diagnostic data or parameters via network 196 for the purpose of identifying or assessing RV and / or LV dysfunction. In some cases, external device 192 can display one or more cardiac measurements indicating right ventricular and / or left ventricular function to the user via input / output device 202.

[0066] In one embodiment, external device 192 may include a secure storage site for diagnostic data or information collected from IMD 16 and / or programmer 24. In this embodiment, network 196 may include an internet network, and trained professionals (such as clinicians) may use computing devices 194a to 194n to securely access the stored diagnostic data or parameters, such as one or more cardiac measurements indicating right ventricular function, one or more cardiac measurements indicating left ventricular function, target CRT settings, and instantaneous CRT settings on external device 192. For example, trained professionals may use secure usernames and passwords to access information stored on external device 192. In one embodiment, external device 192 may be a CareLink server provided by Medtronic, Inc., Minneapolis, Minnesota.

[0067] Figure 6 The text describes, for example, the use of... Figures 1 to 5 An exemplary method 300 for systems and devices to reduce right ventricular load during the implementation of CRT. First, method 300 can be used or configured for patients who have been identified as benefiting from CRT. For example, the patient may have heart failure, impaired left ventricular function, and left bundle branch block, and therefore may be a candidate for CRT. It should be understood that method 300 can be at least in part composed of systems and devices as described herein. Figures 1 to 5 The described implantable medical devices and systems operate automatically.

[0068] However, method 300 may optionally be applied only to patients who also have right ventricular dysfunction. Therefore, method 300 may optionally include determining whether the patient has right ventricular dysfunction 301 before performing the remainder of method 300. For example, one or more cardiac measurements may be measured or monitored from the patient and then used to determine whether the patient has right ventricular dysfunction 301. One or more imaging modalities (such as magnetic resonance imaging (MRI) or echocardiography), one or more electrical sensors (such as external or internal electrodes that measure cardiac electrical activity (electrocardiogram)), and one or more mechanical sensors (such as vibration sensors, microphones, and accelerometers) may be used to determine one or more cardiac measurements.

[0069] In one implementation, the patient's QRS duration (i.e., the duration or interval of the QRS complex) or morphology can be determined using cardiac signals measured or monitored from the patient using one or more internal or external electrodes, and then used to determine whether the patient has right ventricular dysfunction 301. For example, a change in QRS duration or morphology can be generated by comparing, for example, a previous QRS duration or morphology with a current QRS duration or morphology. The previous QRS duration or morphology may have been measured from the patient before experiencing cardiac distress. The change in QRS duration or morphology can be represented by a percentage of QRS change, which can be compared to a QRS change threshold. If the percentage of QRS change is greater than or equal to the QRS change threshold, the patient can be determined to have right ventricular dysfunction. The QRS change threshold can be, for example, between about 5% and about 50%. In one implementation, the QRS change threshold can be 15%. In one embodiment, the QRS change threshold may be greater than or equal to 5%, greater than or equal to 10%, greater than or equal to 12%, greater than or equal to 17%, or greater than or equal to 22%, and / or less than or equal to 50%, less than or equal to 45%, less than or equal to 40%, less than or equal to 35%, less than or equal to 30%, less than or equal to 25%, and less than or equal to 20%. In one embodiment, various imaging techniques such as echocardiography or MRI may be used to determine (e.g., quantify) one or both of right ventricular ejection fraction and stroke volume, which may be used to determine whether a patient has right ventricular dysfunction 301. In one embodiment, right heart catheterization may be used to measure pulmonary artery pressure, which may be used to determine whether a patient has right ventricular dysfunction 301.

[0070] Additionally, one or more cardiac metrics can be measured or monitored from the patient to establish a baseline of the patient's right ventricular function, which can then be used during therapy delivery to determine whether the patient's right ventricular function is deteriorating. For example, the patient's baseline right ventricular function can be compared to the patient's right ventricular function during therapy to determine whether the patient's right ventricular function is improving or deteriorating.

[0071] If the patient is determined to have right ventricular dysfunction 301, method 300 may proceed to deliver CRT 302 using a transient CRT setting. The transient CRT setting can be described as a less aggressive CRT setting than the target CRT setting. The target CRT setting can be configured to optimize left ventricular function and restore the patient's cardiac mechanical synchronicity by electrically activating the heart in a synchronized manner, and the transient CRT setting can be configured to partially optimize left ventricular function and partially restore the patient's cardiac mechanical synchronicity. In other words, the target CRT setting can be the ideal CRT setting as determined by the clinician, and the transient setting can be smaller than the ideal CRT setting, such that full functional recovery of the left ventricle may not be achieved, thereby reducing the burden on the right ventricle.

[0072] Each of the target CRT setting and the instantaneous CRT setting may include one or more settings related to CRT delivery, such as, for example, atrioventricular pacing interval, interventricular pacing interval, left ventricular pacing vector including multi-site pacing vectors (in other words, multi-point pacing (MPP)), pacing amplitude, pulse within each pacing, and ventricular pacing type, such as biventricular pacing, left ventricular pacing only, conventional myocardial pacing (e.g., pacing pulses delivered directly to the myocardial tissue of the patient's heart), cardiac conduction system pacing (e.g., pacing pulses delivered directly to one or more parts of the cardiac conduction system (such as the left bundle branch, right bundle branch, and / or HIS bundle),) and any combination thereof (e.g., left bundle branch optimized CRT and HIS optimized CRT).

[0073] Each target CRT setting in the target CRT settings can be determined before the instantaneous CRT settings are determined. For example, during implantation of an implantable medical device, a physician and / or automated system may configure or attempt each CRT setting in the CRT settings to different values ​​until a target CRT setting is determined that optimizes left ventricular function and restores the mechanical synchronicity of the heart by electrically activating the patient's heart in a synchronized manner. In at least one embodiment, an external 12-lead electrocardiogram (ECG) system may be utilized. In at least one embodiment, a system comprising a plurality of external electrodes (e.g., twenty or more electrodes) positioned around the patient's torso can be used to monitor the patient's electrical heterogeneity and other metrics during the configuration of a CRT setup, as described in U.S. Patent No. 10,064,567, entitled "Systems, Methods, and Interfaces for Identifying Optimal Electrical Vectors," published September 4, 2018; U.S. Patent No. 9,986,928, entitled "Noninvasive Cardiac Therapy Evaluation," published June 5, 2018; U.S. Patent No. 9,764,143, entitled "Systems and Methods for Configuration of Interventricular Interval," published September 9, 2017; and U.S. Patent No. 9,764,143, entitled "Systems and Methods for Configuration of Atrioventricular Interval," published March 7, 2017. The description in U.S. Patent No. 9,586,050, entitled "Interval (Systems and methods for configuring room-interval intervals)," is incorporated herein by reference in its entirety.

[0074] Once the target CRT setting has been determined, the transient CRT setting can be determined based on the target CRT setting. As described herein, the target CRT setting can be configured to optimize left ventricular function and restore the mechanical synchronicity of the heart by electrically activating the patient's heart in a synchronous manner. Conversely, the transient CRT setting can be described as less aggressive than the target CRT setting, thereby reducing right ventricular load during CRT administration, and particularly during the start of CRT delivery and the transition to the target CRT setting. Because the transient CRT setting is less aggressive than the target CRT setting, the transient CRT setting can be described as being configured to partially optimize left ventricular function and partially restore the mechanical synchronicity of the patient's heart. In other words, the transient CRT setting can be described as a CRT setting value that lies between its intrinsic value and the CRT setting value used for the target CRT setting. For example, if CRT settings can be described as optimal percentages, where the target CRT setting is 100% optimal, and the transient CRT setting is below 100% optimal, such as, for example, 90% optimal, 80% optimal, 70% optimal, 60% optimal, 50% optimal, or 40% optimal. Furthermore, the transient CRT setting can be described as a setting smaller than the target CRT setting, thus failing to fully optimize left ventricular function and failing to restore the heart's mechanical synchronicity by synchronously activating the patient's heart. Therefore, the transient CRT setting can be described as not optimal.

[0075] Transient CRT settings may utilize or include transient atrioventricular (AV) pacing intervals, transient interventricular (VV) pacing intervals, transient pacing vectors, and transient ventricular pacing types, one or more of which may be adjusted to partially optimize left ventricular function and partially restore the patient's cardiac mechanical synchrony. For example, if the CRT setting is an AV pacing interval (which is the time interval between an atrial intrinsic pacing event and a ventricular pacing event), the transient AV pacing interval (i.e., the AV pacing interval of the transient CRT setting) may be greater than or longer than the target AV pacing interval (i.e., the AV pacing interval of the target CRT setting), because, for example, a longer AV pacing interval may only partially optimize left ventricular function and only partially restore the patient's cardiac mechanical synchrony in order to reduce right ventricular load. In one implementation, the AV pacing interval of the transient CRT setting may be a selected percentage of the atrioventricular pacing interval of the target CRT setting. The selected AV percentage can be between 50% and 150%. In one embodiment, the selected AV percentage is 125%. In another embodiment, the selected AV percentage can be greater than or equal to 50%, greater than or equal to 70%, greater than or equal to 90%, greater than or equal to 100%, greater than or equal to 110%, or greater than or equal to 120%, and / or less than or equal to 150%, less than or equal to 140%, less than or equal to 135%, or less than or equal to 130%.

[0076] Furthermore, for example, if the CRT setting is an interventricular (VV) pacing interval (which is the time interval between left ventricular pacing events and right ventricular pacing events), then the transient VV pacing interval (i.e., the VV pacing interval set by the transient CRT) can be greater than, longer than, less than, or shorter than the target VV pacing interval (i.e., the VV pacing interval set by the target CRT). The transient VV pacing interval can be greater than or less than the target VV pacing interval, depending on the specific patient; in other words, whether the transient VV pacing interval is greater than or less than the target VV pacing interval can vary depending on the patient. In any case, the transient VV pacing interval will only partially optimize left ventricular function and only partially restore the patient's cardiac mechanical synchronicity in order to reduce right ventricular load. In one implementation, the VV pacing interval set by the transient CRT can be a selected VV percentage of the VV pacing interval set by the target CRT. The selected VV percentage can be between -100% and 200%.

[0077] Furthermore, for example, if the CRT setting is a pacing vector (which defines which one or more electrodes are used to deliver pacing to the left ventricle), the transient pacing vector (i.e., the pacing vector of the transient CRT setting) may not engage or capture as much of the left ventricle as the target pacing vector (i.e., the pacing vector of the target CRT setting), because, for example, a less engaged pacing vector may only partially optimize left ventricular function and only partially restore the patient's cardiac mechanical synchronicity in order to reduce right ventricular load. In one embodiment, in a conventional coronary sinus left ventricular lead, the transient left ventricular pacing vector may utilize a apical-oriented or positioned electrode as the cathode, and the target left ventricular pacing vector may utilize a more basal or lateral-oriented or positioned electrode as the cathode. In one embodiment, in a conventional coronary sinus left ventricular lead, the transient left ventricular pacing vector may utilize a more anteriorly oriented or positioned electrode as the cathode, and the target left ventricular pacing vector may utilize a more posteriorly oriented or positioned electrode as the cathode. In other words, the transient left ventricular pacing vector can be configured to deliver pacing to a first position, and the target left ventricular pacing vector can be configured to deliver pacing to a second position different from the first position. The second position can be more posterior and / or more basal, more lateral, or more basolateral than the first position. Conversely, the first position can be more anteriorly apical than the second position. Additionally, the transient left ventricular pacing vector can utilize a single electrode as a cathode, and the target left ventricular pacing vector can utilize multiple electrodes as cathodes (e.g., multi-point pacing). Furthermore, in another example, when delivering left bundle branch pacing therapy, the transient left ventricular pacing vector can utilize anodic capture, and the target left ventricular pacing vector can utilize cathode capture.

[0078] Furthermore, for example, if the CRT setting is a ventricular pacing type (such as conventional myocardial pacing therapy and cardiac conduction system pacing therapy), then the transient ventricular pacing type can be conventional myocardial pacing therapy, because, for example, conventional myocardial pacing therapy may provide less left ventricular synchrony engagement than cardiac conduction system pacing therapy, so as to only partially optimize left ventricular function and only partially restore the patient’s cardiac mechanical synchrony in order to reduce right ventricular load.

[0079] A transient CRT setting can be delivered to the patient during a transition period 303. The transition period can begin after the pacing device is implanted and the CRT therapy is initially delivered to the patient, and can end after the transition period expires when the patient is ready to receive the target CRT setting. In particular, for example, the transition period can be configured to expire after a preset period, or more preferably, configured or set to expire when it is determined that the right ventricle of the patient's heart is ready to receive the effects of the fully optimized CRT provided by the target CRT setting.

[0080] Therefore, method 300 can check whether the transition period has expired 306. The transition period can be between approximately 2 days and approximately several weeks. In one embodiment, the transition period is 14 days. In one or more embodiments, the transition period can be greater than or equal to 2 days, greater than or equal to 4 days, greater than or equal to 7 days, greater than or equal to 10 days, or greater than or equal to 12 days, and / or less than or equal to 90 days, less than or equal to 60 days, less than or equal to 45 days, less than or equal to 30 days, or less than or equal to 14 days. If the transition period has expired, method 300 can configure the pacing device to deliver CRT for use or configure the pacing device 310 according to the target CRT settings. Similarly, if the transition period has not expired, method 300 can use or continue to deliver CRT according to the instantaneous CRT settings 302.

[0081] Optional, such as Figure 6As shown in the dashed box, method 300 may increase or decrease the aggressiveness of the transient CRT setting during the transition period. For example, method 300 may include determining whether a patient's ventricular function (such as, for example, right ventricular function) is deteriorating based on one or more cardiac measures 304, and reducing the transient CRT setting to a less aggressive level in response to or if the patient's ventricular function is determined to be deteriorating based on one or more cardiac measures 305. The one or more cardiac measures may be similar to or the same as those measures used to determine right ventricular dysfunction 301. For example, QRS duration may be evaluated or assessed to determine whether a patient's right ventricular function is deteriorating 304. In particular, for example, the patient's current QRS duration may be compared to the patient's baseline QRS duration measured before receiving CRT, and if the patient's current QRS duration is worse than the patient's baseline QRS duration, it may be determined that the patient's right ventricular function is deteriorating 304. Additionally, for example, the patient's current QRS duration can be compared to a threshold QRS duration indicating right ventricular dysfunction, and if the patient's current QRS duration is greater than or equal to the threshold QRS duration, it can be determined that the patient's right ventricular function is deteriorating 304. Furthermore, for example, patient-reported symptoms such as shortness of breath can be reported by the patient (e.g., via a user interface transfer device such as a smartphone, directly to a physician, etc.), and if the patient-reported symptoms indicate right ventricular dysfunction (such as shortness of breath), it can be determined that the patient's right ventricular function is deteriorating 304.

[0082] As described herein, if it is determined that a patient's right ventricular function is deteriorating 304, the aggressiveness of the transient CRT settings can be reduced 305. More specifically, for example, one or more transient CRT settings can be adjusted to be less aggressive when applying CRT. For example, the transient AV pacing delay can be increased in increments such as 25 milliseconds (ms) to adjust the transient setting to be less aggressive. Further, for example, the transient VV pacing delay can be increased or decreased by a value such as 10 ms to adjust the transient setting to be less aggressive. Even further, for example, in cases where there are more than two pacing vectors, when adjusting the transient setting to be less aggressive, a pacing vector that is less aggressive than the current pacing vector (e.g., less effective in engaging left ventricular tissue) can be selected.

[0083] Additionally, if the aggressiveness of the instantaneous CRT settings is reduced, method 300 may, for example, issue an alarm 307 to one or more of the patient, clinician, and external server. For example, the alarm may be wirelessly delivered to the patient's smartphone. Further, for example, the alarm may be transmitted to an external server storing medical records using wireless and / or wireless networks, and the alarm may be presented to the patient's clinician.

[0084] In one implementation, once it is determined that a patient's right ventricular function is deteriorating 304, the aggressiveness of the transient CRT setting is reduced 305, and an alarm is issued 307. CRT therapy can continue to be delivered according to the transient CRT setting with reduced aggressiveness until the patient is evaluated by a clinician. In another implementation, once it is determined that a patient's right ventricular function is deteriorating 304, the aggressiveness of the transient CRT setting is reduced 305, and an alarm is issued 307, method 300 can return to process 303 and continue to wait until the transition period expires 306 before adjusting the CRT to the target CRT setting.

[0085] As described above, method 300 can also increase the aggressiveness of the instantaneous CRT setting during the transition period. For example, method 300 can periodically determine whether the transition period has expired 306, and if the transition period has not expired 306 (and no deterioration of ventricular function has been determined), method 300 can adjust the instantaneous CRT setting to be more aggressive 308. More specifically, for example, one or more instantaneous CRT settings can be adjusted to be more aggressive when applying CRT. For example, the instantaneous AV pacing delay can be reduced by a decrease such as 25 ms to adjust the instantaneous setting to be more aggressive. Further, for example, the instantaneous VV pacing delay can be increased or decreased by a value such as 10 ms to adjust the instantaneous setting to be more aggressive. Even further, for example, in the case where there are more than two pacing vectors, when adjusting the instantaneous CRT setting to be more aggressive, a pacing vector that is more aggressive than the current pacing vector (e.g., more effective in engaging left ventricular tissue) can be selected.

[0086] By increasing the aggressiveness 308 of the instantaneous CRT setting during the transition period, the instantaneous CRT setting can gradually approach the target CRT setting, thereby mitigating the transition from the instantaneous CRT setting to the target CRT setting. It should be understood that adjustments to one or more instantaneous CRT settings can be made according to one or more gradient functions. Furthermore, when using a fixed value to increase the aggressiveness of the instantaneous CRT setting as described earlier herein, adjustments to one or more instantaneous CRT settings can be made according to one or more step-like or incremental gradient functions. Therefore, the instantaneous CRT setting can be adjusted over time according to a series of incremental steps or a smooth transition (which can be based on a gradient function).

[0087] For example, Figure 7The graph depicts the instantaneous CRT setting as a function of time. Although the instantaneous CRT setting plotted along the y-axis is the AV pacing interval, it should be understood that any instantaneous CRT setting can be utilized in a similar manner. As shown, the target AV pacing interval is represented by the dashed line 350, and three different gradient AV pacing interval functions 351, 352, and 353 are depicted as decreasing over a transition period until the target AV pacing interval 350 is reached. Each of the three gradient AV pacing interval functions 351, 352, and 353 utilizes a different function to decrease the AV pacing interval, thereby increasing its aggressiveness. Specifically, gradient AV pacing interval function 351 is a linear function (e.g., with a constant negative slope), gradient AV pacing interval function 352 is a power or quadratic function in which the negative slope decreases over time, and gradient AV pacing interval function 353 is a power or quadratic function in which the negative slope increases over time.

[0088] Additionally, it should be understood that the radicality of more than a single instantaneous CRT setting can be increased during the transition period. For example, the radicality of both the AV pacing interval and the VV pacing interval can be increased during the transition period, which can be represented in a three-dimensional graph where time is along the x-axis, the AV pacing interval is along the y-axis, and the VV pacing interval is along the z-axis.

[0089] Furthermore, when CRT settings are actually a binary decision or choice (such as between conventional myocardial pacing therapy and cardiac conduction system pacing therapy), such changes between therapies may occur once during the transition period or only at the end of the transition period, which may depend, for example, on the magnitude of the right ventricular load that such changes will cause.

[0090] Example

[0091] Example Ex1: An implantable medical device, the implantable medical device comprising:

[0092] An electrode device comprising one or more electrodes configured to deliver a cardiac resynchronization therapy (CRT) to a patient's heart using a cardiac resynchronization therapy (CRT) setup and to sense the electrical activity of the patient's heart; and

[0093] A computing device, operatively coupled to the electrode device and including processing circuitry, is configured to:

[0094] Provide a target CRT setting configured to optimize left ventricular function and restore the mechanical synchronicity of the heart by synchronously activating the patient's heart; and

[0095] By delivering CRT to the patient's heart using one or more electrodes according to an aggressive transient CRT setting that is less than the target CRT setting, right ventricular load is reduced during CRT implementation by partially optimizing left ventricular function.

[0096] Example Ex2: An implantable medical device, the implantable medical device comprising:

[0097] An electrode device comprising one or more electrodes configured to deliver a cardiac resynchronization therapy (CRT) to a patient's heart using a cardiac resynchronization therapy (CRT) setup and to sense the electrical activity of the patient's heart; and

[0098] A computing device, operatively coupled to the electrode device and including processing circuitry, is configured to:

[0099] CRT is delivered to the patient's heart using one or more electrodes according to a transient CRT setting, wherein the transient CRT setting is less aggressive than a target CRT setting to partially optimize left ventricular function, thereby reducing right ventricular load; and

[0100] During the transition period, the system transitions from the instantaneous CRT setting to the target CRT setting.

[0101] Example Ex3: A method, the method comprising:

[0102] Cardiac resynchronization therapy (CRT) is delivered to a patient's heart using one or more electrodes from an implantable medical device;

[0103] Provide a target CRT setting configured to optimize left ventricular function and restore the mechanical synchronicity of the heart by synchronously activating the patient's heart; and

[0104] By delivering CRT to the patient's heart using one or more electrodes according to an aggressive transient CRT setting that is less than the target CRT setting, right ventricular load is reduced during CRT implementation by partially optimizing left ventricular function.

[0105] Example Ex4: A method comprising:

[0106] According to a transient cardiac resynchronization therapy (CRT) setup using one or more electrodes on a patient's heart, the CRT is delivered to the patient's heart using the one or more electrodes of an implantable medical device, wherein the transient CRT setup is less aggressive than a target CRT setup to partially optimize left ventricular function, thereby reducing right ventricular load; and

[0107] During the transition period, the system transitions from the instantaneous CRT setting to the target CRT setting.

[0108] Example Ex5: The apparatus according to Examples Ex1 to Ex2 or the method according to Examples Ex3 to Ex4, wherein each of the target CRT setting and the instantaneous CRT setting includes one or more of the atrioventricular pacing interval and the interventricular pacing interval, wherein one or more of the atrioventricular pacing interval and the interventricular pacing interval in the instantaneous CRT setting are selected percentages of one or more of the atrioventricular pacing interval and the interventricular pacing interval in the target CRT setting.

[0109] Example Ex6: The apparatus or method according to Example Ex5, wherein the selected percentage is greater than or equal to 125%.

[0110] Example Ex7: An apparatus or method according to any one of Examples Ex1 to Ex6, wherein each of the target CRT setting and the instantaneous CRT setting includes a left ventricular pacing vector, wherein the left ventricular pacing vector of the instantaneous CRT setting is different from and less aggressive than the left ventricular pacing vector of the target CRT setting.

[0111] Example Ex8: According to the apparatus or method of Example Ex7, the left ventricular pacing vector set by the instantaneous CRT is configured to deliver pacing to a first position, and the left ventricular pacing vector set by the target CRT is configured to deliver pacing to a second position. In one example, the second position is closer to the basal region of the left ventricle than the first position. In one example, the first position is closer to the apical region of the left ventricle than the second position. In one example, the first position is closer to the anterior region of the left ventricle than the second position. In one example, the second position is closer to the posterior region of the left ventricle than the first position. In one example, the first position is closer to the anterior apical region of the left ventricle than the second position. In one example, the second position is closer to the posterolateral or basal region of the left ventricle than the first position.

[0112] Example Ex9: The apparatus or method according to any one of Examples Ex1 to Ex8, wherein each of the target CRT setting and the instantaneous CRT setting includes a ventricular pacing type, wherein the ventricular type of the instantaneous CRT setting is left ventricular pacing only, and the ventricular pacing type of the target CRT setting is biventricular pacing.

[0113] Example Ex10: The apparatus or method according to any one of Examples Ex1 to Ex9, wherein each of the target CRT setting and the instantaneous CRT setting includes a ventricular pacing type, wherein the ventricular type of the instantaneous CRT setting includes at least cardiac conduction system pacing therapy, and the ventricular pacing type of the target CRT setting includes myocardial pacing therapy.

[0114] Example Ex11: An apparatus or method according to any one of Examples Ex1, Ex3, and Ex5 to Ex10, wherein reducing right ventricular load during CRT implementation by delivering CRT to the patient's heart using the one or more electrodes according to a less aggressive transient CRT setting than the target CRT setting comprises: delivering CRT to the patient's heart using the one or more electrodes according to the transient CRT setting for a transition period prior to delivering CRT to the patient's heart using the one or more electrodes according to the target CRT setting.

[0115] The computing device is further configured to perform the following, or the method further includes the following: after the transition period expires, deliver a CRT to the patient's heart using the one or more electrodes according to the target CRT settings.

[0116] Example Ex12: The apparatus or method according to Examples Ex2, Ex4 and Ex11, wherein the transition time period is greater than or equal to one week.

[0117] Example Ex13: According to the apparatus or method of Example Ex11, the transition period for delivering CRT to the patient's heart using the one or more electrodes according to the instantaneous CRT setting before delivering CRT to the patient's heart using the one or more electrodes according to the target CRT setting includes: gradually increasing the aggressiveness of the instantaneous CRT setting during the transition period.

[0118] Example Ex14: The apparatus according to Example Ex2 or the method according to Example Ex4, wherein transitioning from the instantaneous CRT setting to the target CRT setting during the transition period includes: gradually increasing the aggressiveness of the instantaneous CRT setting during the transition period until the target CRT setting is reached.

[0119] Example Ex15: The apparatus or method according to any one of Examples Ex1 to Ex14, wherein the computing device is further configured to perform the following, or the method further includes the following:

[0120] The one or more electrodes are used to monitor one or more cardiac measures indicating right ventricular function;

[0121] Based on one or more cardiac measurements, it is determined that the patient's right ventricular function is deteriorating; and

[0122] Adjust the instantaneous CRT setting to a less aggressive one.

[0123] Example Ex16: The apparatus or method according to Example Ex15, wherein the one or more cardiac measurements include QRS duration.

[0124] It should be understood that the various aspects disclosed herein can be combined with combinations different from those specifically presented in the specification and drawings. It should also be understood that, depending on the example, certain actions or events of any of the processes or methods described herein may be performed in a different order, or may be completely added, combined, or omitted (e.g., performing these techniques may not require all the described actions or events). Furthermore, although for clarity some aspects of this disclosure are described as being performed by a single module or unit, it should be understood that the techniques of this disclosure can be performed by combinations of units or modules associated with, for example, a medical device.

[0125] In one or more examples, the described methods, processes, and techniques (including those attributable to IMD 16, programmer 24, external device 192, and computing device 194n) 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 computer-readable storage medium, which 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 is accessible by a computer).

[0126] 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 circuits. The terms "computing device," "controller," "module," "processor," or "processing circuitry" generally refer to any of the aforementioned logic circuits, alone or in combination with other logic circuits, or any other equivalent circuit. Furthermore, these techniques may be fully implemented in one or more circuits or logic elements. Describing different features as modules or units is intended to highlight different functional aspects and does not necessarily imply that such modules or units must be implemented by separate hardware or software components. Rather, the functionality associated with one or more modules or units may be performed by separate hardware or software components, or integrated into common or separate hardware or software components.

[0127] 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.

[0128] 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.

[0129] As used herein, the term “configured as” may be used interchangeably with the terms “adapted as” or “structured as”, unless otherwise clearly stated in this disclosure.

[0130] The singular forms “a,” “an,” and “the” cover embodiments with plural indicators unless the context clearly indicates otherwise.

[0131] 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."

[0132] 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.

[0133] The terms "preferred" and "ideally" refer to embodiments of this disclosure that may provide certain benefits in certain circumstances. However, other embodiments may also be preferred in the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are useless, nor is it intended to exclude other embodiments from the scope of this disclosure.

Claims

1. An implantable medical device, the implantable medical device comprising: An electrode device comprising one or more electrodes configured to deliver a cardiac resynchronization therapy (CRT) to a patient’s heart using a cardiac resynchronization therapy (CRT) setup and to sense the electrical activity of the patient’s heart; and A computing device, operatively coupled to the electrode device and including processing circuitry, is configured to: CRT is delivered to the patient's heart using one or more electrodes according to a transient CRT setting, wherein the transient CRT setting is less aggressive than a target CRT setting to partially optimize left ventricular function, thereby reducing right ventricular load; and During the transition period, the system transitions from the instantaneous CRT setting to the target CRT setting.

2. A method, the method comprising: Cardiac resynchronization therapy (CRT) is delivered to a patient's heart using one or more electrodes from an implantable medical device, according to a transient CRT setting less aggressive than a target CRT setting to partially optimize left ventricular function, thereby reducing right ventricular load; and During the transition period, the system transitions from the instantaneous CRT setting to the target CRT setting.

3. An implantable medical device, the implantable medical device comprising: An electrode device comprising one or more electrodes configured to deliver a cardiac resynchronization therapy (CRT) to a patient’s heart using a cardiac resynchronization therapy (CRT) setup and to sense the electrical activity of the patient’s heart; and A computing device, operatively coupled to the electrode device and including processing circuitry, is configured to: A target CRT setting is provided, which is configured to optimize left ventricular function and restore the mechanical synchronicity of the heart by electrically activating the patient's heart in a synchronous manner; as well as By delivering CRT to the patient's heart using one or more electrodes according to an aggressive transient CRT setting that is less than the target CRT setting, right ventricular load is reduced during CRT implementation by partially optimizing left ventricular function.

4. A method, the method comprising: Cardiac resynchronization therapy (CRT) is delivered to a patient's heart using one or more electrodes from an implantable medical device; A target CRT setting is provided, which is configured to optimize left ventricular function and restore the mechanical synchronicity of the heart by electrically activating the patient's heart in a synchronous manner; as well as By delivering CRT to the patient's heart using one or more electrodes according to an aggressive transient CRT setting that is less than the target CRT setting, right ventricular load is reduced during CRT implementation by partially optimizing left ventricular function.

5. The apparatus according to any one of claims 1 and 3 or the method according to any one of claims 2 and 4, wherein each of the target CRT setting and the instantaneous CRT setting comprises one or more of the atrioventricular pacing interval and the interventricular pacing interval, wherein one or more of the atrioventricular pacing interval and the interventricular pacing interval of the instantaneous CRT setting are selected percentages of one or more of the atrioventricular pacing interval and the interventricular pacing interval of the target CRT setting.

6. The apparatus or method of claim 5, wherein the selected percentage is greater than or equal to 125%.

7. The apparatus or method according to any one of claims 1 to 6, wherein each of the target CRT setting and the instantaneous CRT setting includes a left ventricular pacing vector, wherein the left ventricular pacing vector of the instantaneous CRT setting is different from and less aggressive than the left ventricular pacing vector of the target CRT setting.

8. The apparatus or method of claim 7, wherein the left ventricular pacing vector set by the instantaneous CRT is configured to deliver pacing to a first position, and the left ventricular pacing vector set by the target CRT is configured to deliver pacing to a second position, wherein the first position is closer to the anterior apex region of the left ventricle than the second position.

9. The apparatus or method according to any one of claims 1 to 8, wherein each of the target CRT setting and the instantaneous CRT setting includes a ventricular pacing type, wherein the ventricular type of the instantaneous CRT setting is left ventricular pacing only, and the ventricular pacing type of the target CRT setting is biventricular pacing.

10. The apparatus or method according to any one of claims 1 to 9, wherein each of the target CRT setting and the instantaneous CRT setting includes a ventricular pacing type, wherein the ventricular type of the instantaneous CRT setting includes at least cardiac conduction system pacing therapy, and the ventricular pacing type of the target CRT setting includes myocardial pacing therapy.

11. The apparatus or method according to any one of claims 3 to 10, wherein reducing right ventricular load during CRT delivery by using the one or more electrodes to deliver CRT to the patient's heart according to a less aggressive transient CRT setting than the target CRT setting to partially optimize left ventricular function comprises: Before delivering CRT to the patient's heart using the one or more electrodes according to the target CRT settings, a transition period is reached when delivering CRT to the patient's heart using the one or more electrodes according to the instantaneous CRT settings. The computing device is further configured to perform the following, or the method further includes the following: after the transition period expires, deliver a CRT to the patient's heart using the one or more electrodes according to the target CRT settings.

12. The apparatus or method according to any one of claims 1 to 2 and 11, wherein the transition time period is greater than or equal to one week.

13. The apparatus or method of claim 11, wherein the transition period for delivering CRT to the patient's heart according to the instantaneous CRT setting before delivering CRT to the patient's heart according to the target CRT setting includes: The aggressiveness of the instantaneous CRT setting is gradually increased during the transition period.

14. The apparatus of claim 1 or the method of claim 2, wherein transitioning from the instantaneous CRT setting to the target CRT setting during the transition time period comprises: During the transition period, the aggressiveness of the instantaneous CRT setting is gradually increased until the target CRT setting is reached.

15. The apparatus or method according to any one of claims 1 to 14, wherein the computing device is further configured to perform the following, or the method further comprises the following: Monitor one or more cardiac measures that indicate right ventricular function; Based on one or more cardiac measurements, it is determined that the patient's right ventricular function is deteriorating; and Adjust the instantaneous CRT setting to a less aggressive one.

16. The apparatus or method of claim 15, wherein the one or more cardiac measurements include QRS duration.

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