Implantable medical systems and methods used to detect, characterize or avoid atrial oversensing within a His IEGM

1. A medical system configured to selectively perform His capture management, the system comprising:

one or more implantable electrodes that can be used for sensing and pacing;

a sensing circuit configured to sense a His intracardiac electrogram (IEGM) using at least one of the one or more implantable electrodes configured to be implanted in or proximate to a patient's His bundle;

a pulse generator configured to selectively produce pacing pulses that are to be delivered to the patient's His bundle using the at least one of the one or more implantable electrodes configured to be implanted in or proximate to the patient's His bundle; and

a controller configured to

cause pacing of the patient's right atrium using at least one of the one or more implantable electrodes configured to be implanted in the patient's right atrium to thereby cause a paced atrial event;

determine whether a portion of the His IEGM exceeds a specified sense threshold within a specified window that begins at an end of an atrioventricular delay (AVD) following the paced atrial event;

detect atrial oversensing based on results of the determining whether the portion of the His IEGM exceeds the specified sense threshold within the specified window;

prevent performance of the His capture management in response to the atrial oversensing being detected; and

after the atrial oversensing has been detected, at a later point in time that the atrial oversensing is no longer detected, cause the His capture management to be performed, which includes causing pacing of the patient's His bundle, using the at least one of the one or more implantable electrodes configured to be implanted in or proximate to the patient's His bundle, and determine a capture threshold associated with the patient's His bundle.

2. The system of claim 1 , wherein:

the specified window, which begins at the end of the AVD following the paced atrial event, comprises an evoked response window; and

the controller, in order to determine whether the portion of the His IEGM exceeds the specified sense threshold within the specified window that begins at the end of the AVD following the paced atrial event, is configured to

at the end of the AVD following the paced atrial event, trigger the evoked response window by causing delivery of a subthreshold pacing pulse to the patient's His bundle using the at least one of the one or more implantable electrodes configured to be implanted in or proximate to the patient's His bundle, the subthreshold pacing pulse having energy below a previously determined capture threshold associated with the patient's His bundle.

3. The system of claim 1 , wherein the controller is configured to:

determine a first onset interval corresponding to a length of time between a beginning of the specified window and when the portion of the His IEGM exceeds the specified sense threshold within the specified window;

cause further pacing of the patient's right atrium to thereby cause a further paced atrial event;

determine whether a further portion of the His IEGM exceeds the specified sense threshold within a further specified window that begins at an end of an extended AVD following the further paced atrial event, wherein the extended AVD is equal to the AVD plus an extension interval that is less than the first onset interval;

determine a second onset interval corresponding to a length of time between a beginning of the further specified window and when the further portion of the His IEGM within the further specified window exceeds the specified sense threshold;

determine whether the second onset interval is equal to the first onset interval minus the extension interval; and

detect the atrial oversensing in response to determining that the second onset interval is equal to the first onset interval minus the extension interval.

4. The system of claim 3 , wherein:

the specified window comprises an evoked response window;

the controller, in order to determine whether the portion of the His IEGM exceeds the specified sense threshold within the specified window, is configured to

at the end of the AVD following the paced atrial event, trigger the evoked response window by causing delivery of a subthreshold pacing pulse to the patient's His bundle using the at least one of the one or more implantable electrodes configured to be implanted in or proximate to the patient's His bundle, the subthreshold pacing pulse having energy below a previously determined capture threshold associated with the patient's His bundle;

the further specified window comprises a further evoked response window; and

the controller, in order to determine whether the further portion of the His IEGM exceeds the specified sense threshold within the further specified window, is configured to

at the end of the extended AVD following the further paced atrial event, trigger the further evoked response window by causing delivery of a further subthreshold pacing pulse to the patient's His bundle using the at least one of the one or more implantable electrodes configured to be implanted in or proximate to the patient's His bundle.

5. A medical system, comprising:

one or more implantable electrodes that can be used for sensing and pacing;

a sensing circuit configured to sense a His intracardiac electrogram (IEGM) using at least one of the one or more implantable electrodes configured to be implanted in or proximate to a patient's His bundle;

one or more pulse generators configured to

selectively produce one or more pacing pulses that are to be delivered to the patient's His bundle using at least one of the one or more implantable electrodes configured to be implanted in or proximate to the patient's His bundle; and

selectively produce one or more ventricular pacing pulses that are to be delivered to the patient's right ventricle using at least one of the one or more implantable electrodes configured to be implanted in the patient's right ventricle; and

a controller configured to

cause sensing or pacing of the patient's right atrium to thereby sense or pace an atrial event;

determine whether a portion of the His IEGM exceeds a specified sense threshold within a specified window within an atrioventricular delay (AVD) following the sensed or paced atrial event;

detect an atrial signal component within the His IEGM based on whether it is determined that the portion of the His IEGM exceeds the specified sense threshold within the specified window within the AVD, wherein detection of the atrial signal component within the His IEGM is indicative of potential atrial oversensing; and

trigger ventricular pacing in response to the portion of the His IEGM exceeding the specified sense threshold within the AVD, or trigger ventricular pacing at an end of the AVD in response to no portion of the His IEGM exceeding the specified sense threshold within the AVD;

wherein the AVD comprises an extended AVD that is long enough to allow for intrinsic atrioventricular (AV) conduction within the AVD.

6. The system of claim 5 , wherein the controller is configured to:

determine an atrial event-to-threshold crossing interval corresponding to a length of time between the paced or sensed atrial event and a respective crossing of the specified sense threshold within the specified window within the AVD;

specify an atrial oversensing avoidance (AOA) period based on the atrial event-to-threshold crossing interval, the AOA period corresponding to when atrial oversensing may occur following paced or sensed atrial events;

detect a peak amplitude of the portion of the His IEGM that exceeds the specified sense threshold within the AOA period;

detect a peak amplitude of a further portion of the His IEGM, following the AOA period, that corresponds to a ventricular depolarization;

determine a ratio of the peak amplitude within the AOA period to the peak amplitude following the AOA period;

determine whether the determined ratio exceeds a specified ratio threshold; and

determine that an atrial oversensing avoidance technique is to be used in response to determining that the determined ratio exceeds the specified ratio threshold.

7. The system of claim 6 , wherein the controller is further configured to:

cause sensing or pacing of the right atrium of the patient to thereby sense or pace a further atrial event; and

determine whether another portion of the His IEGM exceeds a multi-level sense threshold within a specified window that begins following the further sensed or paced atrial event;

wherein the multi-level sense threshold is greater during each said AOA period than following each said AOA period.

8. A method for use with an implantable medical system configured to selectively perform His capture management, the method comprising:

obtaining a His intracardiac electrogram (His IEGM) sensed using at least one electrode implanted in or proximate to a patient's His bundle;

pacing the patient's right atrium using at least one electrode implanted in the patient's right atrium to thereby cause a paced atrial event;

determining whether a portion of the His IEGM exceeds a specified sense threshold within a specified window that begins at an end of an atrioventricular delay (AVD) following the paced atrial event;

detecting atrial oversensing based on results of the determining whether the portion of the His IEGM exceeds the specified sense threshold within the specified window;

preventing performance of the His capture management in response to detecting the atrial oversensing; and

after detecting the atrial oversensing, at a later point in time that the atrial oversensing is no longer detected, performing the His capture management, which includes pacing of the patient's His bundle, using the at least one electrode implanted in or proximate to the patient's His bundle, and determining a capture threshold associated with the patient's His bundle.

9. The method of claim 8 , wherein:

the specified window, which begins at the end of the AVD following the paced atrial event, comprises an evoked response window; and

the determining whether the portion of the His IEGM exceeds the specified sense threshold within the specified window includes

at the end of the AVD following the paced atrial event, triggering the evoked response window by delivering a subthreshold pacing pulse to the patient's His bundle using the at least one electrode that is implanted in or proximate to the patient's His bundle, the subthreshold pacing pulse having energy below a previously determined capture threshold associated with the patient's His bundle.

10. The method of claim 8 , further comprising:

determining a first onset interval corresponding to a length of time between a beginning of the specified window and when the portion of the His IEGM exceeds the specified sense threshold within the specified window;

further pacing the patient's right atrium to thereby cause a further paced atrial event;

determining whether a further portion of the His IEGM exceeds the specified sense threshold within a further specified window that begins at an end of an extended AVD following the further paced atrial event, wherein the extended AVD is equal to the AVD plus an extension interval that is less than the first onset interval;

determining a second onset interval corresponding to a length of time between a beginning of the further specified window and when the further portion of the His IEGM within the further specified window exceeds the specified sense threshold;

determining whether the second onset interval is equal to the first onset interval minus the extension interval; and

detecting the atrial oversensing in response to determining that the second onset interval is equal to the first onset interval minus the extension interval.

11. The method of claim 10 , wherein:

the specified window comprises an evoked response window;

the determining whether the portion of the His IEGM exceeds the specified sense threshold within the specified window includes,

at the end of the AVD following the paced atrial event, triggering the evoked response window by delivering a subthreshold pacing pulse to the patient's His bundle using the at least one electrode implanted in or proximate to the patient's His bundle, the subthreshold pacing pulse having energy below a previously determined capture threshold associated with the patient's His bundle;

the further specified window comprises a further evoked response window; and

the determining whether the further portion of the His IEGM exceeds the specified sense threshold within the further specified window includes,

at the end of the extended AVD following the further paced atrial event, triggering the further evoked response window by delivering a further subthreshold pacing pulse to the patient's His bundle using the at least one electrode implanted in or proximate to the patient's His bundle.

12. A method for use with an implantable medical system, the method comprising:

obtaining a His intracardiac electrogram (His IEGM) sensed using at least one electrode implanted in or proximate to a patient's His bundle;

sensing or pacing a right atrium of the patient to thereby sense or pace an atrial event;

determining whether a portion of the His IEGM exceeds a specified sense threshold within a specified window within an atrioventricular delay (AVD) following the sensed or paced atrial event; and

detecting an atrial signal component within the His IEGM based on results of the determining whether the portion of the His IEGM exceeds the specified sense threshold within the specified window within the AVD, wherein the detecting the atrial signal component within the His IEGM is indicative of potential atrial oversensing; and

triggering ventricular pacing in response to detecting the portion of the His IEGM exceeding the specified sense threshold within the AVD;

wherein the method is performed while the implantable medical system is in one of DDT or DDD mode.

13. The method of claim 12 , further comprising, in response to detecting the atrial signal component within the His IEGM, repeating the obtaining, the sensing or pacing, and the determining one or more times to confirm the detecting of the atrial signal component within the His IEGM.

14. A method for use with an implantable medical system, the method comprising:

obtaining a His intracardiac electrogram (His IEGM) sensed using at least one electrode implanted in or proximate to a patient's His bundle;

sensing or pacing a right atrium of the patient to thereby sense or pace an atrial event;

determining whether a portion of the His IEGM exceeds a specified sense threshold within a specified window within an atrioventricular delay (AVD) following the sensed or paced atrial event; and

detecting an atrial signal component within the His IEGM based on results of the determining whether the portion of the His IEGM exceeds the specified sense threshold within the specified window within the AVD, wherein the detecting the atrial signal component within the His IEGM is indicative of potential atrial oversensing; and

triggering ventricular pacing in response to detecting the portion of the His IEGM exceeding the specified sense threshold within the AVD;

wherein the AVD is long enough to allow for intrinsic atrioventricular conduction within the AVD.

15. A method for use with an implantable medical system, the method comprising:

obtaining a His intracardiac electrogram (His IEGM) sensed using at least one electrode implanted in or proximate to a patient's His bundle;

sensing or pacing the patient's right atrium to thereby sense or pace an atrial event;

determining whether a portion of the His IEGM exceeds a specified sense threshold within a specified window within an atrioventricular delay (AVD) following the sensed or paced atrial event; and

triggering ventricular pacing at an end of the AVD in response to no portion of the His IEGM exceeding the specified sense threshold within the AVD;

wherein the method is performed while the implantable medical system is in one of DDT or DDD mode.

16. A method for use with an implantable medical system, the method comprising:

obtaining a His intracardiac electrogram (His IEGM) sensed using at least one electrode implanted in or proximate to a patient's His bundle;

sensing or pacing a right atrium of the patient to thereby sense or pace an atrial event;

determining whether a portion of the His IEGM exceeds a specified sense threshold within a specified window within an atrioventricular delay (AVD) following the sensed or paced atrial event; and

detecting an atrial signal component within the His IEGM based on results of the determining whether the portion of the His IEGM exceeds the specified sense threshold within the specified window within the AVD, wherein the detecting the atrial signal component within the His IEGM is indicative of potential atrial oversensing;

triggering ventricular pacing in response to detecting the portion of the His IEGM exceeding the specified sense threshold within the AVD;

determining an atrial event-to-threshold crossing interval corresponding to a length of time between the paced or sensed atrial event and a respective crossing of the specified sense threshold; and

specifying an atrial oversensing avoidance (AOA) period based on the atrial event-to-threshold crossing interval, the AOA period corresponding to when atrial oversensing may occur following further paced or sensed atrial events.

17. The method of claim 16 , further comprising, after specifying the AOA period:

determining that a further portion of the His IEGM within the AOA period exceeds the specified sense threshold,

detecting a peak amplitude of the further portion of the His IEGM that exceeds the specified sense threshold within the AOA period;

detecting a peak amplitude of another portion of the His IEGM, following the AOA period, that corresponds to a ventricular depolarization;

determining a ratio of the peak amplitude within the AOA period to the peak amplitude following the AOA period;

determining whether the determined ratio exceeds a specified ratio threshold; and

determining that an atrial oversensing avoidance technique is to be used in response to determining that the determined ratio exceeds the specified ratio threshold.

18. The method of claim 16 , further comprising, after specifying the AOA period, and while the implantable medical system is in DDD mode:

further sensing or pacing the right atrium of the patient to thereby sense or pace a further atrial event; and

determining whether an addition portion of the His IEGM exceeds a multi-level sense threshold within a specified window that begins following the further sensed or paced atrial event;

wherein the multi-level sense threshold is greater during each said AOA period than following each said AOA period.