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CN-122028953-A - Adaptive rate responsive atrioventricular delay

CN122028953ACN 122028953 ACN122028953 ACN 122028953ACN-122028953-A

Abstract

The exemplary devices and methods may use an adaptable rate responsive Atrioventricular (AV) delay profile to deliver cardiac fusion pacing therapies. The rate responsive AV delay profile may generate AV therapy delays based on heart rate and the rate responsive AV delay profile may be adapted based on the intrinsic AV delays of intermittent sampling.

Inventors

  • R.W. Stadler

Assignees

  • 美敦力公司

Dates

Publication Date
20260512
Application Date
20240923
Priority Date
20230928

Claims (15)

  1. 1. A system, the system comprising: an implantable medical device configured to be coupled to one or more electrodes to sense cardiac electrical activity of a patient's heart and deliver cardiac fusion pacing therapy to the patient's heart, the implantable medical device comprising: A computing device comprising processing circuitry and operably coupled to the one or more electrodes, wherein the computing device is configured to: Monitoring the heart rate of the patient; Generating a rate responsive Atrioventricular (AV) therapy delay based on the monitored heart rate using an AV therapy delay profile, wherein the AV therapy delay is a time interval between an atrial event and ventricular pacing, wherein the rate responsive AV delay profile is a relationship between the AV therapy delay and the monitored heart rate over a range of heart rates; delivering cardiac fusion pacing therapy based on the generated AV therapy delay; sampling the intrinsic AV delay, and The rate responsive AV delay profile is adapted in response to the sampled intrinsic AV delay.
  2. 2. A method, the method comprising: Monitoring a heart rate of the patient using one or more electrodes; Generating a rate responsive Atrioventricular (AV) therapy delay based on the monitored heart rate using an AV therapy delay profile, wherein the AV therapy delay is a time interval between an atrial event and ventricular pacing, wherein the rate responsive AV delay profile is a relationship between the AV therapy delay and the monitored heart rate over a range of heart rates; delivering cardiac fusion pacing therapy using the one or more electrodes based on the generated AV therapy delay; sampling the intrinsic AV delay, and The rate responsive AV delay profile is adapted in response to the sampled intrinsic AV delay.
  3. 3. The apparatus of claim 1 or the method of claim 2, wherein the rate responsive AV delay profile comprises: A lower heart rate and a first AV therapy delay corresponding to the lower heart rate, wherein the rate responsive AV delay profile generates the first AV therapy delay in response to the monitored heart rate being less than or equal to the lower heart rate, and A higher heart rate and a second AV therapy delay corresponding to the higher heart rate, wherein the rate responsive AV delay profile generates the second AV therapy delay in response to the monitored heart rate being greater than or equal to the higher heart rate, Wherein a linear relationship extends between the lower heart rate and the higher heart rate such that the rate responsive AV delay profile generates the AV therapy delay based on the linear relationship in response to the monitored heart rate being greater than the lower heart rate and less than the higher heart rate.
  4. 4. A device or method according to any one of claims 1 to 3, wherein the rate responsive AV delay profile comprises one of: Rate responsive pacing AV delay profile for delivering cardiac fusion pacing therapy upon delivery of atrial pacing, and The rate response for delivering cardiac fusion pacing therapy when atrial pacing is not delivered senses the AV delay profile.
  5. 5. The apparatus or method of any of claims 1-4, wherein adapting the rate response AV delay profile in response to the sampled intrinsic AV delay comprises: Generating an adaptive AV delay based on the sampled intrinsic AV delay; Increasing the rate response AV delay profile in response to the adaptive AV delay being greater than an AV therapy delay generated using the rate response AV delay profile at the same monitored heart rate, and The rate responsive AV delay profile is reduced in response to the adaptive AV delay being less than an AV therapy delay generated using the rate responsive AV delay profile at the same monitored heart rate.
  6. 6. The apparatus or method of any of claims 1 to 5, wherein adapting the rate response AV delay profile in response to the sampled intrinsic AV delay comprises changing the rate response AV delay profile by a maximum change limit.
  7. 7. The apparatus or method of any of claims 1 to 6, wherein adapting the rate response AV delay profile in response to the sampled intrinsic AV delay comprises changing the rate response AV delay profile to not greater than a maximum AV delay.
  8. 8. The apparatus or method of any of claims 1 to 7, wherein adapting the rate response AV delay profile in response to the sampled intrinsic AV delay comprises changing the rate response AV delay profile to not less than a minimum AV delay.
  9. 9. The apparatus or method of any of claims 1 to 8, wherein sampling the intrinsic AV delay comprises sampling the intrinsic AV delay in response to expiration of a time interval while the patient is resting.
  10. 10. The device or method of claim 9, wherein the patient is resting when the monitored heart rate is less than or equal to an upper resting heart rate.
  11. 11. The apparatus or method of any of claims 1 to 10, wherein sampling the intrinsic AV delay comprises sampling the intrinsic AV delay in response to two expiration of a time interval when the patient is not resting.
  12. 12. The apparatus or method of claim 11, wherein the time period is greater than 1 minute.
  13. 13. The apparatus or method of any of claims 1-12, wherein sampling the intrinsic AV delay includes sampling the intrinsic AV delay in response to the cardiac fusion pacing therapy switching between delivering atrial pacing and sensing intrinsic atrial activation.
  14. 14. The apparatus or method of any of claims 1-13, wherein the computing device is further configured to perform or the method further comprises delaying the sampling of the intrinsic AV delay in response to a potentially unreliable cardiac cycle for sampling.
  15. 15. The device or method of claim 15, wherein the potentially unreliable cardiac cycle comprises one or more of: a cardiac cycle for which cardiac fusion pacing therapy is to be delivered without atrial pacing and the previous cardiac cycle has cardiac fusion pacing therapy for which atrial pacing has been delivered, and The cardiac fusion pacing therapy with atrial pacing is to be delivered and the previous cardiac cycle has a cardiac cycle that does not deliver cardiac fusion pacing therapy with atrial pacing.

Description

Adaptive rate responsive atrioventricular delay The present application claims priority from U.S. provisional patent application 63/541,149 filed on 9/28 of 2023, the entire contents of which are incorporated herein by reference. The present disclosure relates generally to implantable medical devices and methods having adaptive rate responsive atrioventricular delay for delivering cardiac fusion pacing therapies. Patients with ventricular dyssynchrony but with at least some residual native ventricular activation (e.g., incomplete heart conduction block) and with relatively normal P-wave to R-wave intervals may benefit from improved synchrony resulting from cardiac fusion. Cardiac fusion may be defined as pacing in one or more regions of the myocardium (e.g., ventricular pacing) that occurs simultaneously with intrinsic ventricular depolarizations in other regions of the myocardium, such that the paced and intrinsic activation planes collide. Cardiac fusion pacing therapy may benefit patients during biventricular pacing (e.g., such as conventional Cardiac Resynchronization Therapy (CRT)), left ventricular epicardial only pacing, left bundle branch region pacing (LBBAP), or a combination of LBBAP and left ventricular epicardial only pacing, referred to as left bundle branch region pacing optimized cardiac resynchronization therapy (LOT-CRT). Fusion pacing devices and methods may be described as attempting to maintain fusion of intrinsic ventricular activation and paced ventricular activation in patients with nearly normal P-wave to R-wave intervals. Maintaining optimal fusion over time can be challenging despite the presence of altered cardiac conditions. For example, a physiological change in heart rate is associated with a change in the P-wave to R-wave interval, and a faster heart rate has a shorter P-wave to R-wave interval (PR interval). Thus, maintaining fusion during increased heart rate may be delayed using shortened Atrioventricular (AV) therapy. To this end, the devices and methods may employ a rate responsive AV therapy delay that shortens the AV therapy delay at higher heart rates. However, the rate response AV therapy delay of such devices and methods may not be adaptive or adjustable, e.g., based on physiological changes that manifest as shorter or longer intrinsic AV delays. Additionally, such rate responsive AV therapy delays may be programmed or configured by the clinician at the time of device implantation or by a follow-up appointment, where many parameters (e.g., minimum and maximum heart rates of AV delay change, and minimum and maximum AV delays of sensed atrial events, and minimum and maximum AV delays of paced atrial events) may be set or configured without guidance or feedback to the clinician who will attempt to maintain fusion at the changed heart rate. Further, the apparatus and method may measure the intrinsic AV delay once per minute and use the measured intrinsic AV delay to adjust the AV therapy delay. Thus, such devices and methods may skip the pacing cardiac cycle every minute and keep the AV therapy delay constant during the middle minutes without any adjustment. Disclosure of Invention The present disclosure may be described as balancing several issues. For example, when using the exemplary apparatus and method, AV therapy delay may be adapted more responsively to the physiology of each patient than once per minute. Further, the exemplary apparatus and method may use only two clinically intuitive programmable parameters, such as an upper or maximum limit of atrial sense AV therapy delay and atrial pace AV therapy delay, because the remaining parameters (such as a lower heart rate for each of the atrial sense therapy and atrial pace therapy, a first AV therapy delay corresponding to the lower heart rate, a higher heart rate, a second AV therapy delay corresponding to the higher heart rate, and a minimum AV delay) may be nominally configured because the exemplary apparatus and system are configured to automatically adapt or adjust such parameters. In addition, the exemplary apparatus and method may skip fewer ventricular pacing cardiac cycles (i.e., cardiac cycles receiving ventricular pacing) as measurements or samples, with the inherent AV delay being reduced, as will be described further herein. For example, if the heart rate of the patient remains slow, the ventricular pacing cardiac cycle is skipped at a frequency of about 10% of the device and method for measuring the intrinsic AV delay once per minute. To this end, the present disclosure describes modification of the rate response or adaptive AV delay profile of a fusion pacing mode with left bundle branch region pacing (LBBAP) and/or conventional bi-ventricular Cardiac Resynchronization Therapy (CRT). Thus, the exemplary apparatus and method can be described as avoiding trade-offs—more frequent adjustments can occur without frequent skipping of beats, and it does not utilize many user-programmed parameters to achieve