LCP based predictive timing for cardiac resynchronization

• US 10,894,163 B2
• Filed: 11/07/2017
• Issued: 01/19/2021
• Est. Priority Date: 11/21/2016
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Stahmann, Jeffrey E.
• Primary Examiner(s): Hulbert, Amanda K
• Assistant Examiner(s): Patel, Natasha
• Application Number:
  US15/805,239
• Publication Number:
  US 20180140848A1
• Time in Patent Office: 1,169 Days
• CPC Class Codes: A61N 1/0587 Epicardial electrode systems; Endocardial electrodes piercing the pericardium
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy
• CPC Class Codes: A61N 1/36507 controlled by gradient or slope of the heart potential
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters
• CPC Class Codes: A61N 1/3682 with a variable atrioventricular delay
• CPC Class Codes: A61N 1/37235 Aspects of the external programmer
• CPC Class Codes: A61N 1/37288 Communication to several implantable medical devices within one patient
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators

Abstract

Methods, systems and devices for providing cardiac resynchronization therapy (CRT) to a patient using a leadless cardiac pacemaker (LCP) implanted in or proximate the left ventricle of a patient. A setup phase is used to establish parameters in the therapy delivery. In operation, the method and/or device will sense at least one non-paced cardiac cycle to determine a native R-R interval, and then delivers a synchronization pace at an interval less than the native R-R interval followed by a plurality of pace therapies delivered at the R-R interval or a modification thereof.

Claims

1. A leadless cardiac pacemaker (LCP) configured for implantation entirely within a heart chamber of a patient or adjacent to a heart chamber of a patient, the LCP comprising:

a plurality of electrodes for cardiac therapy delivery and cardiac electrical sensing;

pacing circuitry configured to generate pacing therapy outputs; and

control circuitry configured to analyze signals from the electrodes and to control the use of the pacing circuitry for cardiac resynchronization therapy (CRT);

wherein the control circuitry is configured for;

sensing a native R-R interval from the patient'"'"'s heart;

calculating a synchronization interval by reducing the native R-R interval using a reduction factor;

sensing a native ventricular event;

delivering a synchronization pace therapy upon expiration of the synchronization interval following the native ventricular event; and

delivering a predetermined number, N, of additional pace therapies at intervals approximately equal to the native R-R interval.

2. The LCP of claim 1, wherein the control circuitry is configured to provide the CRT without using an atrial sense reference.

3. The LCP of claim 1, wherein the control circuitry is configured to perform an initialization of CRT to determine the reduction factor by:

determining a PR interval for the patient'"'"'s cardiac activity; and

multiplying the PR interval by a variable, % PR, to calculate the reduction factor.

4. The LCP of claim 1, wherein the control circuitry is configured to perform an initialization of CRT to determine the reduction factor by:

sensing one or more native ventricular events to calculate an RR interval between native ventricular events and a PR interval within one or more native ventricular events;

calculating a RR;

PR ratio as a ratio of the RR interval to the PR interval;

obtaining a variable, % PR, from memory or from an external programmer; and

calculating the reduction factor as one minus the product of the first variable and the % PR; and

further wherein the control circuitry is configured to calculate the synchronization interval by multiplying the reduction factor and the native beat interval.

5. The LCP of claim 1, wherein the control circuitry is configured to perform an initialization of CRT to determine the reduction factor by:

sensing one or more native ventricular events to calculate an RR interval between native ventricular events;

communicating with a second device to determine when P-waves occurred in the one or more native ventricular events and calculating a PR interval;

calculating a RR;

PR ratio as a ratio of the RR interval to the PR interval;

obtaining a variable, % PR, from memory or from an external programmer; and

calculating the reduction factor as one minus the product of the first variable and the % PR; and

further wherein the control circuitry is configured to calculate the synchronization interval by multiplying the reduction factor and the native beat interval.

6. The LCP of claim 1, wherein the control circuitry is configured to monitor patient status and make adjustments to the CRT including:

sensing for a patient condition that would influence the reduction factor;

detecting a change in the patient condition; and

adjusting the reduction factor.

7. The LCP of claim 1, further comprising a posture sensor, wherein the control circuitry is configured to monitor patient posture and make adjustments to the CRT including:

sensing a posture of the patient;

determining whether the patient has changed postures; and

in response to finding that the patient has changed postures, adjusting the reduction factor.

8. The LCP of claim 1, wherein the control circuitry is configured to monitor patient status and make adjustments to the CRT including sensing for a predetermined patient condition that may influence PR interval, and in response to sensing the predetermined patient condition, adjusting “

N”

.

9. The LCP of claim 1, further comprising a posture sensor, wherein the control circuitry is configured to monitor patient posture and make adjustments to the CRT including:

sensing a posture of the patient;

determining that the patient has changed postures between standing and one of sitting or laying down; and

;

if the patient has gone from standing to sitting or laying down, increasing “

N”

;

or

if the patient has gone from sitting or laying down to standing, reducing “

N”

.

10. The LCP of claim 1, wherein the control circuitry is configured to iteratively provide the CRT in sets and to adjust N after delivery of a plurality of sets by:

observing changes in native R-R intervals, to calculate an R-R drift; and

calculating N using the calculated drift.

11. The LCP of claim 1, wherein the control circuitry is configured for at least first and second modes of CRT therapy wherein:

the first mode comprises delivering sets of CRT therapy via the combination of sensing a native R-R interval, delivering a synchronization pace therapy, and delivering a plurality of additional pace therapies;

the second mode comprises obtaining atrial event timing information from a second implantable or wearable medical device to control or optimize pace therapy timing.