Ventricular leadless pacing device mode switching

Patent metadata

Field	Value
Publication number	US-9724519-B2
Application number	US-201514694976-A
Country	US
Kind code	B2
Filing date	Apr 23, 2015
Priority date	Nov 11, 2014
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

In some examples, a leadless pacing device (LPD) is configured to switch from a sensing without pacing mode to ventricular pacing mode in response to determining that no intrinsic ventricular activity was detected within a ventricular event detection window for at least one cardiac cycle, which may be referred to as loss of conduction. The ventricular pacing mode may be selected based on whether atrial oversensing is detected in combination with the loss of conduction. In some examples, an atrio-ventricular synchronous pacing mode is selected in response to detecting loss of conduction and in response to determining that atrial oversensing is not detected. In addition, in some examples, an asynchronous ventricular pacing mode is selected in response to detecting both atrial oversensing and loss of conduction.

First claim

What is claimed is:

1. A method comprising:
sensing an electrical cardiac signal;
detecting, by a processing module of a leadless pacing device, atrial oversensing while the leadless pacing device is in a sensing without pacing mode;
determining, by the processing module and based on the electrical cardiac signal, whether intrinsic ventricular activity is occurring in conjunction with the atrial oversensing;
when the determined intrinsic ventricular activity is occurring in conjunction with the atrial oversensing, controlling, by the processing module, the leadless pacing device to continue operating in the sensing without pacing mode; and
when the determined intrinsic ventricular activity is not occurring in conjunction with the atrial oversensing, controlling, by the processing module, the leadless pacing device to deliver a ventricular pacing pulse to the patient according to an asynchronous ventricular pacing mode.

2. The method of claim 1 , wherein detecting atrial oversensing comprises:
incrementing a value of an atrial oversensing event counter to track an atrial oversensing metric;
comparing the value of the atrial oversensing event counter to an atrial oversensing event threshold value; and
detecting atrial oversensing in response to determining the value is greater than or equal to the atrial oversensing event threshold value.

3. The method of claim 2 , wherein incrementing the value of the atrial oversensing event counter to track an atrial oversensing metric comprises incrementing the value of the atrial oversensing event counter to count the number of successive cardiac cycles in which atrial oversensing was detected.

4. The method of claim 2 , wherein incrementing the value of the atrial oversensing event counter to track an atrial oversensing metric comprises incrementing the value of the atrial oversensing event counter to count the number of cardiac cycles out of a predetermined number of consecutive cardiac cycles in which atrial oversensing was detected.

5. The method of claim 2 , wherein incrementing the value of the atrial oversensing event counter to track an atrial oversensing metric comprises incrementing the value of the atrial oversensing event counter to count the number of cardiac cycles, within a predetermined period of time, in which atrial oversensing was detected.

6. The method of claim 1 , wherein detecting atrial oversensing comprises:
detecting, by the processing module and based on the electrical cardiac signal, a ventricular sense event; and
detecting, by the processing module and based on the electrical cardiac signal, a plurality of atrial activation events within an atrial activation event detection window that begins at the ventricular sense event.

7. The method of claim 6 , further comprising:
incrementing a counter in response to detecting the plurality of atrial activation events within the atrial activation event detection window;
comparing a value of the counter to a threshold value; and
detecting atrial oversensing in response to determining the value of the counter is greater than or equal to the threshold value.

8. The method of claim 7 , wherein the threshold value is two, three or four.

9. The method of claim 7 , wherein the counter is configured to count a number of cardiac cycles in which multiple atrial activation events are detected from among a predetermined number of consecutive cardiac cycles.

10. The method of claim 7 , wherein the counter is configured to count a number of cardiac cycles, within a predetermined time window, in which multiple atrial activation events are detected.

11. The method of claim 7 , wherein the counter is configured to count a successive number of cardiac cycles in which multiple atrial activation events are detected.

12. The method of claim 6 , wherein detecting the plurality of atrial activation events comprises detecting a plurality of P-waves in the sensed electrical cardiac signal.

13. The method of claim 6 , wherein detecting the plurality of atrial activation events comprises:
obtaining a signal indicative of mechanical motion of an atrium; and
detecting the plurality of atrial activation events based on the signal indicative of mechanical motion of the atrium.

14. The method of claim 1 , wherein determining whether intrinsic ventricular activity is occurring comprises:
beginning a ventricular event detection window;
incrementing a value of a loss of conduction counter in response to a ventricular sense event not being detected within the ventricular event detection window;
comparing the value of the loss of conduction counter to a loss of conduction event threshold value; and
determining intrinsic ventricular activity is occurring in response to determining the value is less than or equal to the loss of conduction event threshold value.

15. The method of claim 1 , wherein determining whether intrinsic ventricular activity is occurring comprises:
detecting, by the processing module and based on the electrical cardiac signal, a ventricular sense event;
beginning a ventricular activation detection window in response to detecting the ventricular sense event; and
determining, by the processing module and based on the electrical cardiac signal, a ventricular activation event is detected within the ventricular activation event detection window.

16. The method of claim 15 , further comprising:
incrementing a counter in response to determining no ventricular activation event is detected within the second ventricular activation event detection window;
comparing a value of the counter to a threshold value; and
determining intrinsic ventricular activity is occurring in response to determining the value of the counter is less than or equal to the threshold value.

17. The method of claim 16 , wherein the threshold value is two, three or four.

18. The method of claim 16 , wherein the counter is configured to count a number of cardiac cycles of a predetermined number of cardiac cycles in which no ventricular sense event is detected.

19. The method of claim 16 , wherein the counter is configured to count a number of cardiac cycles, within a predetermined time window, in which no ventricular sense event is detected.

20. The method of claim 16 , wherein the counter is configured to count a successive number of cardiac cycles in which no ventricular sense event is detected.

21. The method of claim 1 , wherein controlling, by the processing module, the leadless pacing device to deliver the ventricular pacing pulse to the patient according to the asynchronous ventricular pacing mode comprises:
detecting a ventricular activation event;
determining whether intrinsic depolarization of the ventricle is detected within a detection window that begins at the ventricular activation event; and
in response to determining that intrinsic depolarization of the ventricle is not detected within the detection window, controlling the leadless pacing device to deliver a pacing pulse to the ventricle.

22. The method of claim 21 , wherein detecting the ventricular activation event comprises detecting a plurality of ventricular activation events, the method further comprising determining an average V-V interval based on the plurality of ventricular activation events and controlling the leadless pacing device to deliver pacing pulses according to the asynchronous ventricular pacing mode at a rate equal to the average V-V interval plus an offset.

23. The method of claim

Assignees

• Medtronic Inc

Inventors

• Demmer Wade M
• Sheldon Todd J

Classifications

• A61N1/3756 Primary

  Casings with electrodes thereon, e.g. leadless stimulators · CPC title

• A61N1/36585 Primary

  controlled by two or more physical parameters · CPC title

• A61N1/37205 Primary

  Microstimulators, e.g. implantable through a cannula · CPC title

• A61N1/3688

  configured for switching the pacing mode, e.g. from AAI to DDD · CPC title