Bi-atrial synchronized left ventricular cardiac pacing

• US 9,233,251 B2
• Filed: 01/16/2014
• Issued: 01/12/2016
• Est. Priority Date: 01/16/2014
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Rajan, Vinayakrishnan, Stegemann, Berthold
• Primary Examiner(s): Lavert, Nicole F
• Application Number:
  US14/157,161
• Publication Number:
  US 20150196760A1
• Time in Patent Office: 726 Days
• Field of Search: 607/9, 607/18
• US Class Current: 1/1
• CPC Class Codes: A61N 1/368 comprising more than one electrode co-operating with different heart regions A61N1/3622, A61N1/3627 take precedence
• CPC Class Codes: A61N 1/3682 with a variable atrioventricular delay
• CPC Class Codes: A61N 1/3684 for stimulating the heart at multiple sites of the ventricle or the atrium
• CPC Class Codes: A61N 1/36842 Multi-site stimulation in the same chamber
• CPC Class Codes: A61N 1/36843 Bi-ventricular stimulation

Abstract

A medical device performs a method for controlling a cardiac pacing therapy. The device determines an inter-atrial conduction time (IACT) and compares the IACT to a threshold. A controller included in the device sets a pacing interval for controlling delivery of pacing pulses to a ventricle to a first ventricular pacing interval that expires after the IACT in response to the IACT being less than the threshold and sets the pacing interval to a second ventricular pacing interval that expires before the IACT in response to the IACT being greater than the threshold.

Claims

1. An automated method for controlling a cardiac pacing therapy, comprising:

determining by a processor an inter-atrial conduction time (IACT);

comparing the IACT to a threshold;

setting a pacing interval for controlling delivery of pacing pulses to a ventricle to a first ventricular pacing interval that expires after the IACT in response to the IACT being less than the threshold; and

setting the pacing interval to a second ventricular pacing interval that expires before the IACT in response to the IACT being greater than the threshold.

2. The method of claim 1, further comprising, setting a left atrial pacing interval to pace the left atrium earlier than an expiration of the IACT.

3. The method of claim 2, further comprising:

setting a left atrial pacing interval to a first left atrial pacing interval that expires earlier than the expiration of the IACT in response to the IACT being less than the threshold;

setting the left atrial pacing interval to a second left atrial pacing interval that expires earlier than the IACT in response to the IACT being greater than the threshold,

the first left atrial pacing interval being a first value less than the IACT,

the second left atrial pacing interval being a second value less than the IACT, the second value being greater than the first value.

4. The method of claim 2, further comprising:

delivering left atrial pacing at the left atrial pacing interval;

withholding the left atrial pacing;

determining a right atrial rate during each of the left atrial pacing and during the withholding; and

adjusting the left atrial pacing interval if the right atrial rate is slower during the withholding than during the left atrial pacing.

5. The method of claim 4, wherein determining the right atrial rate comprises determining an onset of a far-field P-wave from a ventricular electrogram signal.

6. The method of claim 2, further comprising:

delivering left atrial pacing at the left atrial pacing interval;

monitoring a time interval between a left atrial pacing pulse and a sensed ventricular event;

determining that a change in the right atrial rate has occurred in response to detecting a change in the monitored time interval; and

adjusting the left atrial pacing interval in response to determining that the change in the right atrial rate has occurred.

7. The method of claim 1, further comprising:

delivering left atrial pacing at an initial left atrial pacing interval;

monitoring a time interval between a left atrial pacing pulse and a sensed ventricular event during the left atrial pacing;

responsive to a change in the monitored time interval;

delivering the left atrial pacing at a plurality of different left atrial pacing intervals;

determining a time interval between a sensed right atrial event and a sensed ventricular event for each of the plurality of different left atrial pacing intervals;

determining a shortest interval of the plurality of left atrial pacing intervals from which an increase in the left atrial pacing interval does not cause a change in the time interval between the sensed right atrial event and the sensed ventricular event; and

setting the left atrial pacing interval to an adjusted interval that is at least equal to the shortest interval.

8. The method of claim 7, further comprising:

determining an LV-RA time interval between a left ventricular event and right atrial event;

setting the initial left atrial pacing interval in response to the LV-RA time interval;

wherein at least one of determining the LV-RA time interval and determining the time interval between the right atrial events and the sensed ventricular events for each of the plurality of different left atrial pacing intervals comprises determining an onset of a far-field P-wave from a ventricular electrogram signal.

9. The method of claim 1, further comprising:

delivering left atrial pacing pulses earlier than an expiration of the IACT;

monitoring a time interval between the left atrial pacing pulses and respective sensed right ventricular events; and

adjusting a left atrial pacing interval used for delivering the left atrial pacing pulses in response to a change in the monitored time interval.

10. The method of claim 1, further comprising:

sensing cardiac signals from a plurality of electrodes positioned only along a coronary sinus lead; and

determining the IACT solely from the sensed cardiac signals.

11. A medical device for delivering a cardiac pacing therapy, comprising:

a sensing module configured to sense cardiac signals;

a therapy delivery module configured to deliver cardiac pacing pulses;

a controller coupled to the sensing module and the therapy delivery module and configured to;

determine an inter-atrial conduction time (IACT);

compare the IACT to a threshold;

set a pacing interval for controlling delivery of pacing pulses to a ventricle to a first ventricular pacing interval that expires after the IACT in response to the IACT being less than the threshold; and

set the pacing interval to a second ventricular pacing interval that expires before the IACT in response to the IACT being greater than the threshold.

12. The device of claim 11, wherein the controller is further configured to set a left atrial pacing interval to pace the left atrium earlier than an expiration of the IACT.

13. The device of claim 11, wherein the controller is further configured to:

setting a left atrial pacing interval to a first left atrial pacing interval that expires earlier than the expiration of the IACT in response to the IACT being less than the threshold;

setting the left atrial pacing interval to a second left atrial pacing interval that expires earlier than the IACT in response to the IACT being greater than the threshold,

the first left atrial pacing interval being a first value less than the IACT,

the second left atrial pacing interval being a second value less than the IACT, the second value being greater than the first value.

14. The device of claim 12, wherein the controller is further configured to:

control the therapy delivery module to deliver left atrial pacing at the left atrial pacing interval;

withhold the left atrial pacing;

determine a right atrial rate during each of the left atrial pacing and during the withholding; and

adjust the left atrial pacing interval if the right atrial rate is slower during the withholding than during the left atrial pacing.

15. The device of claim 14, wherein determining the right atrial rate comprises determining an onset of a far-field P-wave from a ventricular electrogram signal sensed by the sensing module.

16. The device of claim 12, wherein the controller is further configured to:

control the therapy delivery module to deliver left atrial pacing at the left atrial pacing interval;

monitor a time interval between a left atrial pacing pulse and a sensed ventricular event;

determine that a change in the right atrial rate has occurred in response to detecting a change in the monitored time interval; and

adjust the left atrial pacing interval in response to determining that the change in the right atrial rate has occurred.

17. The device of claim 11, wherein the controller is further configured to:

control the therapy delivery module to deliver left atrial pacing at an initial left atrial pacing interval;

monitor a time interval between a left atrial pacing pulse and a sensed ventricular event during the left atrial pacing;

responsive to a change in the monitored time interval, control the therapy delivery module to deliver the left atrial pacing at a plurality of different left atrial pacing intervals;

determine a time interval between a sensed right atrial event and a sensed ventricular event for each of the plurality of different left atrial pacing intervals;

determine a shortest interval of the plurality of left atrial pacing intervals from which an increase in the left atrial pacing interval does not cause a change in the time interval between the sensed right atrial event and the sensed ventricular event; and

set the left atrial pacing interval to an adjusted interval that is at least equal to the shortest interval.

18. The device of claim 17, wherein the controller is further configured to:

determine an LV-RA time interval between a left ventricular event and right atrial event; and

set the initial left atrial pacing interval in response to the LV-RA time interval;

wherein at least one of determining the LV-RA time interval and determining the time interval between the right atrial events and the sensed ventricular events for each of the plurality of different left atrial pacing intervals comprises determining an onset of a far-field P-wave from a ventricular electrogram signal.

19. The device of claim 11, wherein the controller is further configured to:

control the therapy control module to deliver left atrial pacing pulses earlier than an expiration of the IACT;

monitor a time interval between the left atrial pacing pulses and respective sensed right ventricular events; and

adjust a left atrial pacing interval used for delivering the left atrial pacing pulses in response to a change in the monitored time interval.

20. The device of claim 11, wherein the sensing module is configured to sense cardiac signals from a plurality of electrodes positioned only along a coronary sinus lead;

and

the controller is configured to determine the IACT solely from the sensed cardiac signals.

21. A non-transitory, computer-readable storage medium storing instructions for causing a medical device to:

determine an inter-atrial conduction time (IACT);

compare the IACT to a threshold;

set a pacing interval for controlling delivery of pacing pulses to a ventricle to a first ventricular pacing interval that expires after the IACT in response to the IACT being less than the threshold; and

set the pacing interval to a second ventricular pacing interval that expires before the IACT in response to the IACT being greater than the threshold.

22. A medical device for delivering a cardiac pacing therapy, comprising:

sensing means for sensing cardiac signals;

processing means for determining an inter-atrial conduction time (IACT) from the sensed cardiac signals and comparing the IACT to a threshold; and

control means for;

setting a pacing interval for controlling delivery of pacing pulses to a ventricle to a first ventricular pacing interval that expires after the IACT in response to the IACT being less than the threshold; and

setting the pacing interval to a second ventricular pacing interval that expires before the IACT in response to the IACT being greater than the threshold.