WO2025109430A1

WO2025109430A1 - Selective anodal and cathodal stimulation

Info

Publication number: WO2025109430A1
Application number: PCT/IB2024/061284
Authority: WO
Inventors: Robert C. KOWAL; Wade M. Demmer; Robert W. Stadler
Original assignee: Medtronic Inc
Current assignee: Medtronic Inc
Priority date: 2023-11-22
Filing date: 2024-11-13
Publication date: 2025-05-30
Anticipated expiration: 2026-05-22

Abstract

A medical device system includes a medical device configured to deliver ventricular pacing to a heart of a patient. The medical device system further includes processing circuitry configured to receive cardiac electrogram data of a patient sensed by the medical device during delivery of ventricular pacing. The processing circuitry is further configured to identify one or more heartbeats within the cardiac electrogram data. The processing circuitry is further configured to determine one or more patient parameters based on the one or more heartbeats. The processing circuitry is further configured to control the medical device to deliver cathodal pacing or anodal-cathodal pacing based on the one or more patient parameters.

Description

SELECTIVE ANODAL AND CATHODAL STIMULATION

FIELD

[0001] The disclosure relates generally to medical device systems.

CROSS REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority from U.S. Provisional Patent Application 63/602,092 filed 22 November 2023, the entire content of which is incorporated herein by reference.

BACKGROUND

[0003] Medical devices may be used to monitor physiological signals of a patient. For example, some medical devices are configured to sense cardiac electrogram (EGM) signals indicative of the electrical activity of the heart via electrodes. Some medical devices may be configured to deliver a therapy in conjunction with or separate from the monitoring of physiological signals. For example, cardiac pacing is an effective therapy for treating patients with bradycardia due to sinus node dysfunction or atrioventricular block. However, traditional right ventricular apical pacing (RVAP) can cause electrical and mechanical dyssynchrony.

SUMMARY

[0004] Conduction system pacing, such as left bundle branch area pacing (LBBAP) therapy, is a physiological pacing approach that activates the normal cardiac conduction pathways and provides synchronized contraction of ventricles. Conduction system pacing may involve the placement of an electrode (e.g., a distal tip electrode) of a pacing lead in or near a heart’s electrical conduction system to restore normal electrical conduction and improve cardiac function.

[0005] Medical devices like pacemakers or implantable cardioverter-defibrillators (ICDs) may send electrical signals to the heart. A device may deliver pacing via a cathode electrode at target heart tissue, e.g., on a distal tip of a lead or device located in the heart tissue (e.g., the LBB) and an anode electrode located outside the heart, such as the device’s metal case (sometimes referred to as a “can”). When the device sends an electrical signal, it travels from the cathode in the heart, through the heart muscle, and then back to the anode electrode on the device’s case.

[0006] In some examples, a medical device may capture tissue in the heart using two electrodes (e.g., two relatively closely spaced electrodes on a lead or pacing device). When the device sends an electrical signal, it travels from the cathode electrode (e.g., the more distal electrode on the lead) in the target heart tissue, through the heart muscle, and then back to the anode electrode (e.g., the less distal electrode on the lead). With this configuration, the cathode electrode at the cardiac tissue typically captures the cardiac tissue, and any tissue proximate to or in contact with the anode electrode is not captured. For certain patients or certain arrhythmia states within a patient, however, capturing tissue via the anode electrode can be beneficial.

[0007] Thus, in accordance with techniques of this disclosure, a medical device may be configured to switch between cathodal-only stimulation (e.g., only capturing via the cathode electrode) and anodal-cathodal (AC) stimulation (e.g., capturing via the cathode and anode electrodes) based on measured patient parameters. For example, if a patient has normal atrioventricular conduction, the medical device may deliver cathodal-only LBBAP or left ventricular stimulation and fuse the paced activation with the native activation of the right ventricle. However, if a patient has prolonged atrioventricular conduction (e.g., a conduction time greater than 200 milliseconds), the patient may no longer have appropriate timing of native activation of the right ventricle. Thus, the medical device may advantageously switch to delivering AC stimulation to activate both ventricles of the heart. The anodal stimulation may activate the right ventricle while the cathodal stimulation activates the left ventricle, correcting the long atrioventricular delay while providing interventricular and intraventricular synchrony. In this way, the medical device may deliver more efficacious therapy to treat the patient, improving health outcomes.

[0008] In some examples, a medical device system includes a medical device configured to deliver ventricular pacing to a heart of a patient; and processing circuitry configured to: receive cardiac electrogram data of a patient sensed by the medical device during delivery of ventricular pacing; identify one or more heartbeats within the cardiac electrogram data; determine one or more patient parameters based on the one or more heartbeats; and control the medical device to deliver cathodal pacing or anodal-cathodal pacing based on the one or more patient parameters.

[0009] In some examples, a medical device includes a cathode electrode configured to deliver ventricular pacing to a heart of a patient; an anode electrode configured to deliver ventricular pacing to the heart; and processing circuitry configured to: receive cardiac electrogram data of a patient sensed by the medical device during delivery of ventricular pacing; identify one or more heartbeats within the cardiac electrogram data; determine one or more patient parameters based on the one or more heartbeats; and control the medical device to deliver cathodal pacing or anodal-cathodal pacing based on the one or more patient parameters.

[0010] In some examples, a method includes receiving, by processing circuitry, cardiac electrogram data of a patient sensed by the medical device during delivery of ventricular pacing; identifying, by the processing circuitry, one or more heartbeats within the cardiac electrogram data; determining, by the processing circuitry, one or more patient parameters based on the one or more heartbeats; and controlling, by the processing circuitry, the medical device to deliver cathodal pacing or anodal-cathodal pacing based on the one or more patient parameters.

[0011] The summary is intended to provide an overview of the subject matter described in this disclosure. It is not intended to provide an exclusive or exhaustive explanation of the systems, device, and methods described in detail within the accompanying drawings and description below. Further details of one or more examples of this disclosure are set forth in the accompanying drawings and in the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 illustrates the environment of an example medical system in conjunction with a patient.

[0013] FIG. 2 is a functional block diagram illustrating an example configuration of an implantable medical device (IMD). [0014] FIG. 3 is a functional block diagram illustrating an example configuration of an external device.

[0015] FIG. 4 is a block diagram illustrating an example system that includes an access point, a network, external computing devices, such as a server, and one or more other computing devices, which may be coupled to an IMD and external device.

[0016] FIG. 5 is a flowchart of an example method for operating a medical device to transition from cathodal left bundle branch area pacing to anodal cathodal left bundle branch and septal pacing in accordance with techniques of this disclosure.

[0017] Like reference characters denote like elements throughout the description and figures.

DETAILED DESCRIPTION

[0018] Conduction system pacing (CSP), also known as physiologic pacing, refers to one form of the medical procedure and technology used to regulate the heartbeat when the heart's natural electrical conduction system is not functioning properly. The heart relies on a specialized conduction system to generate and transmit electrical signals that coordinate the contraction of its chambers, ensuring efficient blood pumping. When there are abnormalities or disorders in the heart's conduction system, it can lead to irregular heart rhythms (e.g., arrhythmias) or heart rate abnormalities. In such cases, medical devices, such as pacemakers, are used to restore and maintain a normal heart rate and rhythm. [0019] Left bundle branch area pacing (LBBAP), a form of CSP, is a specialized cardiac pacing technique used in patients with certain heart conduction disorders. LBBAP involves the placement of a cathode electrode, e.g., a distal tip electrode, of a pacing lead or device in or near the left bundle branch of the heart’s electrical conduction system to restore normal electrical stimulation of the ventricles and improve cardiac function. The left bundle branch (LBB) is a critical part of the heart's conduction system responsible for transmitting electrical signals to the ventricles, which are the lower chambers of the heart. When there is a block or delay in the LBB, the coordination and timing of ventricular contractions can be compromised, leading to inefficient pumping of blood. In left bundle branch pacing (LBBP), the lead delivers electrical impulses to the LBB, bypassing the conduction block or delay. By stimulating the left bundle branch directly (e.g., LBBP) or indirectly (e.g., LBBAP), LBBP or LBBAP (respectively) can restore synchronized activation of the ventricles, improving their pumping efficiency.

[0020] Cathodal and AC pacing are both methods for delivering electrical impulses to the heart tissue during cardiac pacing. Cathodal pacing (which may be more common than AC pacing) may use a cathode electrode (e.g., on a lead) to deliver the electrical impulse to the heart, while an anode electrode (e.g., the housing of the medical device) acts as a ground or reference point. The electrical circuit is completed by the current flowing from the cathode electrode to the heart tissue and then to the anode electrode.

[0021] In some examples, a medical device may capture tissue in the heart using a cathode electrode and anode electrode positioned in close proximity to each other within the heart (e.g., both the anode and cathode electrodes are positioned on a lead). When the device sends an electrical signal, it travels from the cathode electrode (e.g., the more distal electrode on the lead) in the target heart tissue, through the heart muscle, and then back to the anode electrode (e.g., the less distal electrode on the lead).

[0022] With this configuration, the cathode electrode at the cardiac tissue typically captures the cardiac tissue, and any tissue proximate to or in contact with the anode electrode is not captured. For certain patients or certain arrhythmia conditions, however, capturing tissue via the anode electrode can be beneficial. Thus, in accordance with techniques of this disclosure, a medical device may be configured to switch between cathodal-only pacing (“cathodal pacing”) and anodal-cathodal (AC) stimulation based on measured patient parameters. For example, if a patient has normal atrioventricular conduction, the medical device may deliver cathodal pacing and fuse the paced activation with the native activation of the right ventricle. However, if a patient experiences a period of prolonged atrioventricular conduction (e.g., a conduction time (and/or atrioventricular (AV) delay) greater than 200 milliseconds), the medical device may advantageously switch to delivering AC stimulation to activate both ventricles of the heart. The anodal stimulation may activate the right ventricle while the cathodal stimulation activates the left ventricle, correcting the long atrioventricular delay while providing interventricular and intraventricular synchrony.

[0023] FIG. 1 is a conceptual diagram of a medical device system 2 capable of pacing and sensing in a patient’s heart 8. Medical device system 2 may include implantable medical device (IMD) 10 and an external device 12. IMD 10 may be in wireless communication with at least one of external device 12 and other devices not pictured in FIG. 1. IMD 10 may be implanted within a patient, and coupled to one or more implantable medical leads. IMD 10 may be configured to sense one or more cardiac electrograms (EGMs) and deliver conduction system pacing, such as LBBAP, via the plurality of electrodes.

[0024] External device 12 may be a computing device with a display viewable by the user and an interface for providing input to external device 12 (i.e., a user input mechanism). In some examples, external device 12 may be a notebook computer, tablet computer, workstation, one or more servers, cellular phone, personal digital assistant, or another computing device that may run an application that enables the computing device to interact with IMD 10. In some examples, external device 12 may be implemented as a number of computing systems configured to receive cardiac electrical signals, which may include at least one EGM signal input received directly or indirectly from IMD 10. In some examples, external device 12 is a computing device included in a remote patient monitoring system such as a computing device included in the CARELINK® monitoring system available from Medtronic, Inc., Minneapolis, Minnesota.

[0025] External device 12 is configured to communicate with IMD 10 and, optionally, another computing device (not illustrated in FIG. 1), via wireless communication.

External device 12, for example, may communicate via near-field communication technologies (e.g., inductive coupling, NFC or other communication technologies operable at ranges less than 10-20 cm) and far-field communication technologies (e.g., RF telemetry according to the 802.11 or Bluetooth® specification sets, or other communication technologies operable at ranges greater than near-field communication technologies).

[0026] External device 12 may be used to configure operational parameters for IMD 10. External device 12 may be used to retrieve data from IMD 10. The retrieved data may include values of patient parameters measured by IMD 10, indications of episodes of arrhythmia or other maladies detected by IMD 10, and physiological signals recorded by IMD 10. As discussed in greater detail below with respect to FIG. 4, one or more remote computing devices may interact with IMD 10 in a manner similar to external device 12, e.g., to program IMD 10 and/or retrieve data from IMD 10, via a network.

[0027] Processing circuitry of medical device system 2 (e.g., of IMD 10, external device 12, and/or of one or more other computing devices) may be configured to perform the example techniques of this disclosure for controlling IMD 10 to selectively deliver cathodal or AC pacing based on patient parameters.

[0028] IMD 10 may be coupled to a heart 8 via transvenous electrical leads 16 and 18. Housing 15 of IMD 10 may enclose internal circuitry corresponding to various circuits and components for sensing cardiac signals from heart 8 and delivering cardiac pacing therapy. In some examples, IMD 10 may be configured to detect tachyarrhythmias from the sensed cardiac signals and deliver high voltage cardioversion/defibrillation (CV/DF) shocks to heart 8, e.g., for terminating a detected ventricular tachycardia or ventricular fibrillation.

[0029] Lead 16 may be a RA lead (“RA lead 16”), and lead 18 may be a ventricular conduction system pacing lead (“VCS pacing lead 18). RA lead 16 and VCS pacing lead 18 may be advanced transvenously to position electrodes for sensing cardiac electrical signals and delivering pacing therapy. RA lead 16 may be positioned such that its distal end is in, or in the vicinity of, the right atrium. RA lead 16 may carry pacing and sensing electrodes 20 and 22, shown as a tip electrode and a ring electrode, respectively.

Electrodes 20 and 22 provide sensing and pacing in the RA and are each connected to a respective insulated conductor extending within the elongated body of RA lead 16. IMD 10 may include a connector block configured to receive a lead connector for electrically coupling conductors extending from the distal electrodes 20 and 22 to circuitry within housing 15 via electrical feedthroughs crossing housing 15.

[0030] VCS lead 18 may be advanced within the right atrium to position a tip electrode 32 and a ring electrode 34 for pacing and sensing in the vicinity of the VCS, e.g., at or near the LBB, from a right atrial approach, as shown. VCS tip electrode 32 may be a helical electrode. VCS tip electrode 32 can be advanced into the inferior end of the interatrial septum, beneath the AV node and near the tricuspid valve annulus to position tip electrode 32 in, along or proximate to the His bundle. Ring electrode 34 spaced proximally from tip electrode 32 may be used as the return electrode with the cathode tip electrode 32 for pacing the right and left ventricles via the native His-Purkinje conduction system.

[0031] IMD 10 may produce an intracardiac EGM signal from the cardiac electrical signal received via a sensing electrode vector that may include tip electrode 32 and/or ring electrode 34 of VCS lead 18. The electrodes 32 and 34 are coupled to respective insulated conductors extending within the elongated body of VCS lead 18, which provide electrical connection to a proximal lead connector coupled to circuitry of IMD 10 within housing 15 via electrical feedthroughs crossing housing 15.

[0032] Housing 15 may function as a return electrode for unipolar sensing or pacing configurations with any of the electrodes carried by leads 16 and 18. Electrodes 32 and 34 may be used in a bipolar pacing electrode pair for delivering VCS pacing pulses and for receiving a cardiac electrical signal for sensing intrinsic and pacing evoked QRS waveforms. In some examples, IMD 10 may be configured to sense a far field (FF) cardiac signal, e.g., using electrode 32 and housing 15 or using electrode 34 and housing 15, and/or a near field (NF) cardiac signal, e.g., using electrodes 32 and 34, for processing and analysis for determining a capture type. Electrodes 32 and 34 may be used in a sensing electrode vector for sensing intrinsic R-waves for use in determining a heart rhythm and a need for electrical stimulation therapy.

[0033] In FIG. 1 , IMD 10 is a dual chamber device configured to receive RA lead 16, positioned in the right atrial chamber for delivering atrial pacing pulses and sensing atrial electrical signals via electrodes 20 and 22. IMD 10 may be configured to sense intrinsic atrial P-waves and deliver atrial pacing pulses in the absence of sensed P-waves. IMD 10 may be configured to deliver atrial synchronized ventricular pacing by setting an AV delay in response to each sensed P-wave or delivered atrial pacing pulse and deliver a ventricular pacing pulse to the VCS via lead 18 upon the expiration of the AV delay.

[0034] VCS lead 18 may be advanced transvenously into the RV via the RA for positioning tip electrode 32 within inter- ventricular septum 19. Tip electrode 32 may be selected as a pacing cathode electrode in combination with ring electrode 34 as the return anode electrode for pacing and capturing the LBB and/or RBB in various examples. In some instances, the pacing magnitude (e.g., pulse amplitude and/or pulse width) may be selected to achieve cathodal capture at the cathode electrode for capturing at least one bundle branch. In some instances, the pacing pulse amplitude and/or pulse width may be selected to achieve cathodal and anodal capture, which may capture the LBB and the right side of the ventricular septum. In some instances, the LBB and the RBB may be captured concurrently to provide dual or bilateral bundle branch (BB) pacing using a single bipolar electrode pair.

[0035] In other examples, either tip electrode 32 or ring electrode 34 may be selected as a cathode electrode paired with housing 15 in a unipolar pacing electrode vector. Unipolar pacing may capture a single BB or location within the ventricles. While VCS lead 18 is shown carrying one pacing and sensing electrode pair, tip electrode 32 and ring electrode 34, it is to be understood that in other examples, VCS lead 18 may include multiple electrodes along its distal portion to provide one or more selectable bipolar pacing electrode vectors and/or one or more unipolar pacing electrode vectors (e.g., with housing 15) for delivering pacing pulses to the left and right side of the ventricular septum.

[0036] Furthermore, VCS lead 18 may include one or more coil electrodes, e.g., coil electrode 35, when IMD 10 is configured as an ICD capable of delivering high voltage shock therapies. Coil electrode 35 may be used in sensing electrode vectors, e.g., with either of tip electrode 32 or ring electrode 34, for sensing a ventricular EGM signal that may be analyzed processing of system (e.g., of IMD 10) for classifying VCS pacing pulse capture type.

[0037] As described above, IMD 10 may communicate via wireless telemetry with external device 12. External device 12 may receive EGM signals from IMD 10 sensed using any available electrodes shown in FIG. 1 or in other examples described or shown in the accompanying drawings for processing and analysis according to the techniques disclosed herein.

[0038] Although IMD 10 is generally described herein as a pacemaker (including an intracardiac pacemaker) that delivers conduction system pacing and determines whether the pacing results in effective conduction system pacing, example systems including one or more implantable or external devices of any type configured to sense a cardiac EGM may be configured to implement the techniques of this disclosure. [0039] FIG. 2 is a functional block diagram illustrating an example configuration of IMD 10 of FIG. 1 in accordance with one or more techniques described herein. In the illustrated example, IMD 10 includes electrodes 51 which may be located on one or more leads (e.g., lead 16), processing circuitry 50, sensing circuitry 52, communication circuitry 54, storage device 56, therapy delivery circuitry 58, and sensors 62. Electrodes 51 may include electrodes described herein, such as electrodes 20, 22, 32, 34, etc.

[0040] Processing circuitry 50 may include fixed function circuitry and/or programmable processing circuitry. Processing circuitry 50 may include any one or more of a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or equivalent discrete or analog logic circuitry. In some examples, processing circuitry 50 may include multiple components, such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, or one or more FPGAs, as well as other discrete or integrated logic circuitry. The functions attributed to processing circuitry 50 herein may be embodied as software, firmware, hardware or any combination thereof. [0041] Sensing circuitry 52 may be coupled to electrodes 51. Sensing circuitry 52 may sense signals from electrodes 51, e.g., to produce a cardiac EGM, in order to facilitate monitoring the electrical activity of the heart. Sensing circuitry 52 also may monitor signals from sensors 62, which may include one or more accelerometers, pressure sensors, and/or optical sensors, as examples. In some examples, sensing circuitry 52 may include one or more filters and amplifiers for filtering and amplifying signals received from electrodes 51 and/or sensors 62. Sensing circuitry 52 may include switching circuitry for selecting electrodes 51 and their polarity for sensing the cardiac EGM signals described herein.

[0042] Sensing circuitry 52 and/or processing circuitry 50 may be configured to detect cardiac depolarizations (e.g., P- waves of atrial depolarizations, R- waves of ventricular depolarizations, etc.) when the cardiac EGM amplitude crosses a sensing threshold. For cardiac depolarization detection, sensing circuitry 52 may include a rectifier, filter, amplifier, comparator, and/or analog-to-digital converter, in some examples. In some examples, sensing circuitry 52 may output an indication to processing circuitry 50 in response to sensing of a cardiac depolarization. In this manner, processing circuitry 50 may receive detected cardiac depolarization indicators corresponding to the occurrence of detected R- waves and P- waves in the respective chambers of heart. Processing circuitry 50 may use the indications of detected R-waves and P-waves for determining interdepolarization intervals, heart rate, and detecting arrhythmias, such as tachyarrhythmias and asystole.

[0043] Communication circuitry 54 may include any suitable hardware, firmware, software or any combination thereof for communicating with another device, such as external device 12, another networked computing device, or another IMD or sensor. Under the control of processing circuitry 50, communication circuitry 54 may receive downlink telemetry from, as well as send uplink telemetry to external device 12 or another device with the aid of an internal or external antenna. In addition, processing circuitry 50 may communicate with a networked computing device via an external device (e.g., external device 12) and a computer network, such as the Medtronic CareLink® Network. Communication circuitry 54 may be configured to transmit and/or receive signals via inductive coupling, electromagnetic coupling, Near Field Communication (NFC), Radio Frequency (RF) communication, Bluetooth, WiFi, or other proprietary or non-proprietary wireless communication schemes.

[0044] In some examples, storage device 56 includes computer-readable instructions that, when executed by processing circuitry 50, cause IMD 10 and processing circuitry 50 to perform various functions attributed to IMD 10 and processing circuitry 50 herein. Storage device 56 may include any volatile, non-volatile, magnetic, optical, or electrical media, such as a random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically-erasable programmable ROM (EEPROM), flash memory, or any other digital media. Storage device 56 may store, as examples, programmed values for one or more operational parameters of IMD 10 and/or data collected by IMD 10 for transmission to another device using communication circuitry 54. Data stored by storage device 56 and transmitted by communication circuitry 54 to one or more other devices may include digitized cardiac EGMs and other patient parameters.

[0045] Therapy delivery circuitry 58 may be configured to generate and deliver electrical therapy (e.g., pacing pulses) to heart 8 of a patient via electrodes 51. In some examples, therapy delivery circuitry 58 may include capacitors, current sources, and/or regulators. Therapy delivery circuitry 58 may include switching circuitry for selecting electrodes 51 and their polarity for delivering therapy signals to heart 8. Therapy delivery circuitry 58 may deliver electrical stimulation therapy via electrodes 51 according to one or more therapy parameter values, which may be stored in storage device 56. The therapy parameter values may, in the case of pacing pulses, include magnitude values, such as pulse amplitude and width.

[0046] IMD 10 may be configured to deliver LBB AP in order to provide synchronous LV contraction via selective or non-selective stimulation of the LBB or pacing on the left side of the ventricular septum, adjacent to the LBB. Asynchronous ventricle activation can be normalized or improved with the application of LBB AP. Patients with predominant left-sided conduction disturbances can achieve both intraventricular and interventricular synchrony if LBBAP is applied with proper timing such that paced LV activation fuses with native activation of the right ventricle. Achieving this result may require proper selection of the AV delay for LBBAP to match the patient’s native AV conduction (e.g., as indicated by an interval between a P-wave and an intrinsic R-wave). For example, if a patient demonstrates a normal intrinsic AV conduction, properly timed LBBAP can provide AV synchrony as well as interventricular and intraventricular synchrony. Thus, if the patient’s intrinsic AV conduction is normal (e.g., a P-R interval equal to or less than 200 milliseconds), cathodal capture of LBBAP may be preferred to AC pacing of the LBB area.

[0047] In accordance with techniques of this disclosure, processing circuitry 50 may be configured to control therapy delivery circuitry 58 to selectively deliver cathodal pacing and AC pacing based on patient parameters. In general, the patient parameters may indicate a health condition of a patient that may be more responsive to either cathodal pacing or bipolar stimulation. For example, patients with atrioventricular block, atrial fibrillation, etc., may benefit more from AC pacing than cathodal pacing. Thus, selectively delivering cathodal pacing and AC pacing based on patient parameters may result in better treatment, improving health outcomes. In general, the techniques and apparatus of this disclosure may be applicable in any situation that causes IMD 10 to pace in a non-atrial- tracking mode. An indication or determination of a non-functional atrial lead (e.g., due to arrhythmias) is another possible use case for the techniques and apparatus. [0048] As an example, processing circuitry 50 may control therapy delivery circuitry 58 to deliver cathodal stimulation or AC stimulation based on whether a patient has prolonged atrioventricular conduction, also known as first-degree heart block or AV block Type I (or any other type of AV block, such as second-degree heart block, third-degree heart block, etc.). AV block is a cardiac conduction disorder characterized by an electrical signal transmission from the atria (upper chambers) to the ventricles (lower chambers) of the heart that is slower than normal, or completely blocked. In a healthy heart, the electrical impulses travel smoothly and rapidly through the AV node, which is responsible for transmitting signals between the atria and ventricles. For example, the P-R interval for a healthy heart may be 200 milliseconds or less.

[0049] In some examples, processing circuitry 50 may determine whether a patient has prolonged atrioventricular conduction based on whether a P-R interval of a patient satisfies (e.g., exceeds) a threshold (e.g., 200 milliseconds). If the P-R interval of a patient is equal to or less than the threshold, a patient may have a normal P-R interval, indicating that a patient has timely native activation of the right ventricle. Accordingly, fusing (e.g., blending or integrating) the cathodal pacing provided by lead 16 and the natural depolarization of the right ventricle may be desirable.

[0050] Processing circuitry 50 may measure the interval between an atrial sense (or an atrial pacing pulse) and ventricular sensing to measure the P-R interval. A normal or intrinsic P-R interval may be a P-R interval of 200 milliseconds or less. For atrial pacing, a normal P-R may be a P-R interval of about 250 milliseconds or less, assuming the atrial pacing rate is not excessively overdriving the normal sinus rate.

[0051] Therapy delivery circuitry 58 may deliver cathodal pacing using tip electrode 32 as the cathode and housing 15 as the ground. Alternatively, therapy delivery circuitry 58 may deliver cathodal pacing using tip electrode 32 as the cathode and ring electrode 34 as the ground, but at a magnitude that avoids anodal stimulation at ring electrode 34. In this latter example, therapy delivery circuitry 58 may deliver cathodal stimulation by outputting the pulses at an amplitude equal to or less than 2 milliamps, though this amplitude may vary from patient to patient.

[0052] On the other hand, if the P-R interval of a patient is greater than the threshold, a patient may have prolonged atrioventricular conduction, indicating that a patient may no longer have timely native activation of the right ventricle. That is, if the patient’s atrioventricular conduction is prolonged, hemodynamics suffer from the loss of AV synchrony and the detrimental effects of losing AV synchrony can outweigh the benefits of fusion between LBBAP and intrinsic right ventricular activation. In this situation, applying LBBAP earlier than required for optimal fusion between LBBAP and native right-sided activation may be necessary.

[0053] Processing circuitry 50 may control therapy delivery circuitry 58 to deliver AC pacing via tip electrode 32 and ring electrode 34 to activate both ventricles of heart 8. In other words, tip electrode 32 may be selected as a pacing cathode electrode in combination with ring electrode 34 as the return anode electrode for pacing and capturing the ventricles based on patient parameters (e.g., delayed or absent AV conduction, as indicated by a suprathreshold P-R interval). For example, processing circuitry 50 may configure the pacing magnitude of the pacing pulse delivered by therapy delivery circuitry 58. In some instances, the pacing pulse amplitude and/or pulse width may be selected to achieve only cathodal capture at the cathode electrode. In other instances, the pacing pulse amplitude and/or pulse width may be selected to achieve cathodal and anodal capture.

[0054] For example, processing circuitry 50 may cause therapy delivery circuitry 58 to deliver AC pacing by increasing the amplitude of the pulses (e.g., to 2.5 milliamps or greater), resulting in anodal stimulation by ring electrode 34. The anodal stimulation may activate the right ventricle while the cathodal stimulation activates the left ventricle, correcting the long atrioventricular delay while providing interventricular and intraventricular synchrony in a patient with long AV delays.

[0055] Processing circuitry 50 may be configured to determine the proper amplitude for capture. For example, when pacing tip-to-can or tip-to-ring (or in some examples tip- to- coil), processing circuitry 50 may determine the cathodal threshold for capture. In some examples, processing circuitry 50 may pace separately from ring to can or ring to coil to determine the capture threshold for anodal stimulation. In some examples, processing circuitry 50 may analyze changes in EGM morphology or the timing for depolarization to arrive at a distant sensing location as the pacing output changes. For example, processing circuitry 50 may pace tip-to-ring at low outputs. Processing circuitry 50 may use the EGM morphology as a baseline or reference for cathodal capture while increasing the pacing amplitude from tip-to-ring. Processing circuitry 50 may determine when the EGM morphology changes from the baseline (in response to an increase in the pacing amplitude), and in turn determine the threshold for A-C capture.

[0056] Although primarily discussed herein within the context of AV block, it should be understood that the techniques of this disclosure may be applied to other medical conditions and other patient parameters in a substantially similar manner. That is, the techniques of this disclosure may generally be applied to selectively deliver cathodal pacing or AC pacing based on whether patient parameters satisfy one or more criteria (e.g., by comparing a patient parameter to a threshold). Also, it should be understood that the state of a given patient may change over time, such that at one time cathodal pacing is preferable for that patient and at another time AC pacing is preferable for that patient. Accordingly, an advantage of the techniques and apparatus of this disclosure is periodically monitoring the patient parameters (e.g., whether the patient’s P-R interval and/or AV delay is greater than 200 milliseconds) and responding to transient rhythm changes within a patient.

[0057] FIG. 3 is a block diagram illustrating an example configuration of components of external device 12. In the example of FIG. 3, external device 12 includes processing circuitry 80, communication circuitry 82, storage device 84, and user interface 86.

[0058] Processing circuitry 80 may include one or more processors that are configured to implement functionality and/or process instructions for execution within external device 12. For example, processing circuitry 80 may be capable of processing instructions stored in storage device 84. Processing circuitry 80 may include, for example, microprocessors, DSPs, ASICs, FPGAs, or equivalent discrete or integrated logic circuitry, or a combination of any of the foregoing devices or circuitry. Accordingly, processing circuitry 80 may include any suitable structure, whether in hardware, software, firmware, or any combination thereof, to perform the functions ascribed herein to processing circuitry 80. [0059] Communication circuitry 82 may include any suitable hardware, firmware, software or any combination thereof for communicating with another device, such as IMD 10. Under the control of processing circuitry 80, communication circuitry 82 may receive downlink telemetry from, as well as send uplink telemetry to, IMD 10, or another device. Communication circuitry 82 may be configured to transmit or receive signals via inductive coupling, electromagnetic coupling, Near Field Communication (NFC), Radio Frequency (RF) communication, Bluetooth, WiFi, or other proprietary or non-proprietary wireless communication schemes. Communication circuitry 82 may also be configured to communicate with devices other than IMD 10 via any of a variety of forms of wired and/or wireless communication and/or network protocols.

[0060] Storage device 84 may be configured to store information within external device 12 during operation. Storage device 84 may include a computer-readable storage medium or computer-readable storage device. In some examples, storage device 84 includes one or more of a short-term memory or a long-term memory. Storage device 84 may include, for example, RAM, DRAM, SRAM, magnetic discs, optical discs, flash memories, or forms of EPROM or EEPROM. In some examples, storage device 84 is used to store data indicative of instructions for execution by processing circuitry 80. Storage device 84 may be used by software or applications running on external device 12 to temporarily store information during program execution.

[0061] Data exchanged between external device 12 and IMD 10 may include operational parameters. External device 12 may transmit data including computer readable instructions which, when implemented by IMD 10, may control IMD 10 to change one or more operational parameters and/or export collected data. For example, processing circuitry 80 may transmit an instruction to IMD 10 which requests IMD 10 to export collected data (e.g., digitized cardiac EGMs) to external device 12. In turn, external device 12 may receive the collected data from IMD 10 and store the collected data in storage device 84. Processing circuitry 80 may implement any of the techniques described herein to control therapy delivery circuitry 58 to selectively deliver AC or cathodal pacing via electrodes 51.

[0062] A user, such as a clinician or a patient, may interact with external device 12 through user interface 86. User interface 86 includes a display (not shown), such as a liquid crystal display (LCD) or a light emitting diode (LED) display or other type of screen, with which processing circuitry 80 may present information related to IMD 10, e.g., cardiac EGMs, pacing magnitude, etc. In addition, user interface 86 may include an input mechanism to receive input from the user. The input mechanisms may include, for example, any one or more of buttons, a keypad (e.g., an alphanumeric keypad), a peripheral pointing device, a touch screen, or another input mechanism that allows the user to navigate through user interfaces presented by processing circuitry 80 of external device 12 and provide input. In other examples, user interface 86 also includes audio circuitry for providing audible notifications, instructions or other sounds to the user, receiving voice commands from the user, or both.

[0063] FIG. 4 is a block diagram illustrating an example system that includes an access point 90, a network 92, external computing devices, such as a server 94, and one or more other computing devices 100A-100N (collectively, “computing devices 100”), which may be coupled to IMD 10 and external device 12 via network 92, in accordance with one or more techniques described herein. In this example, IMD 10 may use communication circuitry 54 to communicate with external device 12 via a first wireless connection, and to communicate with an access point 90 via a second wireless connection. In the example of FIG. 4, access point 90, external device 12, server 94, and computing devices 100 are interconnected and may communicate with each other through network 92.

[0064] Access point 90 may include a device that connects to network 92 via any of a variety of connections, such as telephone dial-up, digital subscriber line (DSL), or cable modem connections. In other examples, access point 90 may be coupled to network 92 through different forms of connections, including wired or wireless connections. In some examples, access point 90 may be a user device, such as a tablet or smartphone, that may be co-located with the patient. IMD 10 may be configured to transmit data, such as data regarding the pacing magnitude and/or cardiac EGMs, to access point 90. Access point 90 may then communicate the retrieved data to server 94 via network 92.

[0065] In some cases, server 94 may be configured to provide a secure storage site for data that has been collected from IMD 10 and/or external device 12. In some cases, server 94 may assemble data in web pages or other documents for viewing by trained professionals, such as clinicians, via computing devices 100. One or more aspects of the illustrated system of FIG. 4 may be implemented with general network technology and functionality, which may be similar to that provided by the Medtronic CareLink® Network. [0066] In some examples, one or more of computing devices 100 may be a tablet or other smart device located with a clinician, by which the clinician may program, receive data from, and/or interrogate IMD 10. For example, the clinician may access data collected by IMD 10 through a computing device 100, such as when a patient is in in between clinician visits, to check on a status of a medical condition or the operation of IMD 10. In some examples, the clinician may enter instructions for a medical intervention for a patient into an application executed by computing device 100, such as based on a status of a patient condition determined by IMD 10, external device 12, server 94. or any combination thereof, or based on other patient data known to the clinician. Device 100 then may transmit the instructions for medical intervention to another of computing devices 100 located with a patient or a caregiver of a patient. For example, such instructions for medical intervention may include an instruction to change a drug dosage, timing, or selection, to schedule a visit with the clinician, or to seek medical attention. In further examples, a computing device 100 may generate an alert to a patient based on a status of a medical condition of a patient, which may enable a patient proactively to seek medical attention prior to receiving instructions for a medical intervention. In this manner, a patient may be empowered to take action, as needed, to address his or her medical status, which may help improve clinical outcomes for a patient.

[0067] In the example illustrated by FIG. 4, server 94 includes a storage device 96, e.g., to store data retrieved from IMD 10, and processing circuitry 98. Although not illustrated in FIG. 4, computing devices 100 may similarly include a storage device and processing circuitry. Processing circuitry 98 may include one or more processors that are configured to implement functionality and/or process instructions for execution within server 94. For example, processing circuitry 98 may be capable of processing instructions stored in memory 96. Processing circuitry 98 may include, for example, microprocessors, DSPs, ASICs, FPGAs, or equivalent discrete or integrated logic circuitry, or a combination of any of the foregoing devices or circuitry. Accordingly, processing circuitry 98 may include any suitable structure, whether in hardware, software, firmware, or any combination thereof, to perform the functions ascribed herein to processing circuitry 98. Processing circuitry 98 of server 94 and/or the processing circuity of computing devices 100 may implement any of the techniques described herein to analyze cardiac EGMs received from IMD 10, e.g., to determine whether to deliver AC pacing or cathodal pacing.

[0068] Storage device 96 may include a computer-readable storage medium or computer-readable storage device. In some examples, memory 96 includes one or more of a short-term memory or a long-term memory. Storage device 96 may include, for example, RAM, DRAM, SRAM, magnetic discs, optical discs, flash memories, or forms of EPROM or EEPROM. In some examples, storage device 96 is used to store data indicative of instructions for execution by processing circuitry 98.

[0069] FIG. 5 is a flow diagram illustrating an example method for operating a medical device to transition from cathodal LBB AP to anodal-cathodal left bundle branch area pacing and right septal pacing in accordance with techniques of this disclosure. Although the example operation of FIG. 5 is described as being performed by processing circuitry 50 of IMD 10, in other examples some or all of the example operation may be performed by processing circuitry of another device and with respect to any cardiac EGM. [0070] IMD 10 may sense one or more cardiac EGMs of a patient during delivery of ventricular pacing. To be more specific, IMD 10 may refrain from delivering ventricular pacing for at least one beat (resulting in a normal or intrinsic beat that is not corrupted by premature atrial contractions (PAC) or premature ventricular contractions (PVC) and has a normal A- A interval).

[0071] Processing circuitry 50 may receive the cardiac EGMs and identify heartbeats within the EGMs (500). Processing circuitry 50 may determine one or more patient parameters based on the heartbeats (502). The patient parameters may include an atrioventricular synchrony metric, such as a P-R interval and/or AV delay. For example, IMD 10 may measure the time duration between when IMD 10 paces the atrium and when IMD 10 senses activity in the ventricle, the time duration between when IMD 10 senses electrical activity in the atrium and when IMD 10 senses electrical activity in the ventricle, etc. These time durations may represent or otherwise be associated with the P-R interval and/or other patient parameters. Based on the patient parameters, processing circuitry 50 may control therapy delivery circuitry 58 to deliver cathodal pacing or AC pacing, as some patients may benefit more from cathodal pacing, and other patients may benefit more from AC pacing (504). Indeed, a given patient may at one time benefit more from cathodal pacing, and at another time benefit more from AC pacing.

[0072] For example, a patient experiencing prolonged atrioventricular conduction (e.g., periodically) may benefit more from AC pacing than cathodal pacing. Thus, processing circuitry 50 may control therapy delivery circuitry 58 to deliver AC pacing if or when the patient has prolonged atrioventricular conduction (e.g., as indicated by a P-R interval and/or AV delay of the patient) and cathodal pacing if the patient has normal atrioventricular conduction. For example, processing circuitry 50 may periodically determine whether a patient has prolonged atrioventricular conduction based on whether a P-R interval of a patient satisfies (e.g., exceeds) a threshold (e.g., 200 milliseconds). If the P-R interval of a patient is equal to or less than the threshold, a patient may have a normal P-R interval, indicating that a patient has native activation of the right ventricle.

[0073] Responsive to the P-R interval satisfying the threshold, processing circuitry 50 may control therapy delivery circuitry 58 to deliver AC pacing. Responsive to the P-R interval not satisfying the threshold, processing circuitry 50 may control therapy delivery circuitry 58 to deliver cathodal pacing. In this way, the techniques and apparatus of this disclosure may allow for more personalized health treatment, thereby potentially improving patient outcomes.

[0074] As another example, when the patient goes into atrial fibrillation, atrial flutter, or atrial tachycardia, the pacemaker may switch into a non-atrial-tracking mode. In a nontracking mode, it may not be possible to time LBBAP or LBBP to achieve fusion with the patient’s intrinsic RV activation. Therefore, during non-tracking pacing, IMD 10 may advantageously provide AC pacing. If IMD 10 later switches back to an atrial tracking mode (e.g., when atrial fibrillation terminates), the ventricular pacing can switch back to cathode-only LBBAP or LBBP, once an appropriate AV interval has been measured.

[0075] Another situation that may benefit from AC pacing is when IMD 10 switches to a non-atrial-tracking mode caused by observation that the atrial lead is no longer functioning, for example, when the measured atrial pacing impedance is out of range or when the automatic determination of atrial capture threshold cannot provide a detected atrial capture threshold.

[0076] The following examples are illustrative of the techniques described herein. [0077] Example 1 : A medical device system includes a medical device configured to deliver ventricular pacing to a heart of a patient; and processing circuitry configured to: receive cardiac electrogram data of a patient sensed by the medical device during delivery of ventricular pacing; identify one or more heartbeats within the cardiac electrogram data; determine one or more patient parameters based on the one or more heartbeats; and control the medical device to deliver cathodal pacing or anodal-cathodal pacing based on the one or more patient parameters.

[0078] Example 2: The medical device system of example 1, wherein the processing circuitry is configured to control the medical device to deliver cathodal pacing or anodal- cathodal pacing by determining whether at least one of the one or more patient parameters satisfies a threshold.

[0079] Example 3 : The medical device system of example 2, wherein the one or more patient parameters includes an atrioventricular synchrony metric.

[0080] Example 4: The medical device system of example 3, wherein the atrioventricular synchrony metric includes at least one of a P-R interval or an atrioventricular delay.

[0081] Example 5: The medical device system of example 4, wherein the processing circuitry is configured to: determine whether at least one of the P-R interval or the atrioventricular delay satisfies the threshold; control the medical device to deliver anodal- cathodal pacing in response to at least one of the P-R interval or the atrioventricular delay satisfying the threshold; and control the medical device to deliver cathodal pacing in response to at least one of the P-R interval or the atrioventricular delay not satisfying the threshold.

[0082] Example 6: The medical device system of example 5, wherein the processing circuitry is configured to determine that at least one of the P-R interval or the atrioventricular delay satisfies the threshold in response to at least one of the P-R interval or the atrioventricular delay being greater than the threshold, and wherein the threshold is 200 milliseconds.

[0083] Example 7: The medical device system of any of examples 1 to 6, wherein the processing circuitry is configured to control the medical device to deliver anodal-cathodal pacing to treat one or more of atrioventricular block or atrial fibrillation. [0084] Example 8: The medical device system of any of examples 1 to 7, wherein the medical device includes a lead configured to deliver the ventricular pacing, wherein the lead includes a cathode electrode and an anode electrode.

[0085] Example 9: The medical device system of example 8, wherein the cathode electrode is a tip electrode, and wherein the anode electrode is a ring electrode.

[0086] Example 10: The medical device system of example 9, wherein the ventricular pacing includes left bundle branch area pacing.

[0087] Example 11 : A medical device includes a cathode electrode configured to deliver ventricular pacing to a heart of a patient; an anode electrode configured to deliver ventricular pacing to the heart; and processing circuitry configured to: receive cardiac electrogram data of a patient sensed by the medical device during delivery of ventricular pacing; identify one or more heartbeats within the cardiac electrogram data; determine one or more patient parameters based on the one or more heartbeats; and control the medical device to deliver cathodal pacing or anodal-cathodal pacing based on the one or more patient parameters.

[0088] Example 12: The medical device of example 11, wherein the processing circuitry is configured to control the medical device to deliver cathodal pacing or anodal- cathodal pacing by determining whether at least one of the one or more patient parameters satisfies a threshold.

[0089] Example 13: The medical device of example 12, wherein the one or more patient parameters includes an atrioventricular synchrony metric.

[0090] Example 14: The medical device of example 13, wherein the atrioventricular synchrony metric includes at least one of a P-R interval or an atrioventricular delay.

[0091] Example 15: The medical device of example 14, wherein the processing circuitry is configured to: determine whether at least one of the P-R interval or the atrioventricular delay satisfies the threshold; control the medical device to deliver anodal- cathodal pacing in response to at least one of the P-R interval or the atrioventricular delay satisfying the threshold; and control the medical device to deliver cathodal pacing in response to at least one of the P-R interval or the atrioventricular delay not satisfying the threshold. [0092] Example 16: The medical device of example 15, wherein the processing circuitry is configured to determine that at least one of the P-R interval or the atrioventricular delay satisfies the threshold in response to at least one of the P-R interval or the atrioventricular delay being greater than the threshold, and wherein the threshold is 200 milliseconds.

[0093] Example 17 : The medical device of any of examples 11 to 16, wherein the processing circuitry is configured to control the medical device to deliver anodal-cathodal pacing to treat one or more of atrioventricular block or atrial fibrillation.

[0094] Example 18: The medical device of any of examples 11 to 17, wherein the medical device includes a lead including a cathode electrode and an anode electrode.

[0095] Example 19: The medical device of example 18, wherein the cathode electrode is a tip electrode, and wherein the anode electrode is a ring electrode.

[0096] Example 20: The medical device of example 19, wherein the ventricular pacing includes left bundle branch pacing.

[0097] Example 21 : A method includes receiving, by processing circuitry, cardiac electrogram data of a patient sensed by the medical device during delivery of ventricular pacing; identifying, by the processing circuitry, one or more heartbeats within the cardiac electrogram data; determining, by the processing circuitry, one or more patient parameters based on the one or more heartbeats; and controlling, by the processing circuitry, the medical device to deliver cathodal pacing or anodal-cathodal pacing based on the one or more patient parameters.

[0098] The techniques described in this disclosure may be implemented, at least in part, in hardware, software, firmware, or any combination thereof. For example, various aspects of the techniques may be implemented within one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated or discrete logic QRS circuitry, as well as any combinations of such components, embodied in external devices, such as physician or patient programmers, stimulators, or other devices. The terms “processor” and “processing circuitry” may generally refer to any of the foregoing logic circuitry, alone or in combination with other logic circuitry, or any other equivalent circuitry, and alone or in combination with other digital or analog circuitry. [0099] For aspects implemented in software, at least some of the functionality ascribed to the systems and devices described in this disclosure may be embodied as instructions on a computer-readable storage medium such as RAM, DRAM, SRAM, magnetic discs, optical discs, flash memories, or forms of EPROM or EEPROM. The instructions may be executed to support one or more aspects of the functionality described in this disclosure.

[0100] In addition, in some aspects, the functionality described herein may be provided within dedicated hardware and/or software modules. Depiction of 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 realized by separate hardware or software components. Rather, functionality associated with one or more modules or units may be performed by separate hardware or software components, or integrated within common or separate hardware or software components. Also, the techniques could be fully implemented in one or more circuits or logic elements. The techniques of this disclosure may be implemented in a wide variety of devices or apparatuses, including an IMD, an external programmer, a combination of an IMD and external programmer, an integrated circuit (IC) or a set of ICs, and/or discrete electrical circuitry, residing in an IMD and/or external programmer.

Claims

CLAIMS What is claimed is:

1. A medical device system comprising: a medical device configured to deliver ventricular pacing to a heart of a patient; and processing circuitry configured to: receive cardiac electrogram data of a patient sensed by the medical device during delivery of ventricular pacing; identify one or more heartbeats within the cardiac electrogram data; determine one or more patient parameters based on the one or more heartbeats; and control the medical device to deliver cathodal pacing or anodal- cathodal pacing based on the one or more patient parameters.

2. The medical device system of claim 1, wherein the processing circuitry is configured to control the medical device to deliver cathodal pacing or anodal-cathodal pacing by determining whether at least one of the one or more patient parameters satisfies a threshold.

3. The medical device system of claim 2, wherein the one or more patient parameters comprises an atrioventricular synchrony metric.

4. The medical device system of claim 3, wherein the atrioventricular synchrony metric comprises at least one of a P-R interval or an atrioventricular delay.

5. The medical device system of claim 4, wherein the processing circuitry is configured to: determine whether at least one of the P-R interval or the atrioventricular delay satisfies the threshold; control the medical device to deliver anodal-cathodal pacing in response to at least one of the P-R interval or the atrioventricular delay satisfying the threshold; and control the medical device to deliver cathodal pacing in response to at least one of the P-R interval or the atrioventricular delay not satisfying the threshold.

6. The medical device system of claim 5, wherein the processing circuitry is configured to determine that at least one of the P-R interval or the atrioventricular delay satisfies the threshold in response to at least one of the P-R interval or the atrioventricular delay being greater than the threshold, and wherein the threshold is 200 milliseconds.

7. The medical device system of any of claims 1 to 6, wherein the processing circuitry is configured to control the medical device to deliver anodal-cathodal pacing to treat one or more of atrioventricular block or atrial fibrillation.

8. The medical device system of any of claims 1 to 7, wherein the medical device comprises a lead configured to deliver the ventricular pacing, wherein the lead comprises a cathode electrode and an anode electrode.

9. The medical device system of claim 8, wherein the cathode electrode is a tip electrode, and wherein the anode electrode is a ring electrode.

10. The medical device system of claim 9, wherein the ventricular pacing comprises left bundle branch area pacing.

11. A medical device comprising: a cathode electrode configured to deliver ventricular pacing to a heart of a patient; an anode electrode configured to deliver ventricular pacing to the heart; and processing circuitry configured to: receive cardiac electrogram data of a patient sensed by the medical device during delivery of ventricular pacing; identify one or more heartbeats within the cardiac electrogram data; determine one or more patient parameters based on the one or more heartbeats; and control the medical device to deliver cathodal pacing or anodal- cathodal pacing based on the one or more patient parameters.

12. The medical device of claim 11, wherein the processing circuitry is configured to control the medical device to deliver cathodal pacing or anodal-cathodal pacing by determining whether at least one of the one or more patient parameters satisfies a threshold.

13. The medical device of claim 12, wherein the one or more patient parameters comprises an atrioventricular synchrony metric.

14. The medical device of claim 13, wherein the atrioventricular synchrony metric comprises at least one of a P-R interval or an atrioventricular delay.

15. The medical device of claim 14, wherein the processing circuitry is configured to: determine whether at least one of the P-R interval or the atrioventricular delay satisfies the threshold; control the medical device to deliver anodal-cathodal pacing in response to at least one of the P-R interval or the atrioventricular delay satisfying the threshold; and control the medical device to deliver cathodal pacing in response to at least one of the P-R interval or the atrioventricular delay not satisfying the threshold.