Implantable medical device and method for determining His bundle pacing capture

Patent metadata

Field	Value
Publication number	US-10773086-B2
Application number	US-201816183867-A
Country	US
Kind code	B2
Filing date	Nov 8, 2018
Priority date	Nov 8, 2017
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

An IMD system receives a near field His bundle electrical signal produced by a patient's heart via a first sensing electrode vector and a far field cardiac electrical signal via a second sensing electrode vector different than the first sensing electrode vector. The IMD system generates His bundle pacing pulses delivered to the patient's heart via a His pacing electrode vector and determines a type of cardiac capture evoked by a His bundle pacing pulse.

First claim

What is claimed is:

1. An implantable medical device system, comprising:
a sensing circuit configured to:
receive a near field His bundle electrical signal via a first sensing electrode vector, and
receive a far field cardiac electrical signal via a second sensing electrode vector that is different than the first sensing electrode vector;

a therapy delivery circuit configured to generate His bundle pacing pulses delivered to a patient's heart via a His pacing electrode vector; and
a control circuit configured to:
determine a type of cardiac capture evoked by a His bundle pacing pulse delivered by the therapy delivery circuit by:
detecting a near field QRS signal from the near field His bundle electrical signal following the His bundle pacing pulse;
determining a time interval from the His bundle pacing pulse to the near field QRS signal;
comparing the time interval to a first time interval threshold;
in response to the time interval being less than the first time interval threshold, determining a feature of the far field cardiac electrical signal;
comparing the far field cardiac electrical signal feature to a non-selective His bundle capture threshold;
determining the type of cardiac capture as being non-selective His bundle capture that includes capture of both of a His bundle and ventricular myocardium in response to at least the far field cardiac electrical signal feature being less than the non-selective His bundle capture threshold; and
determining the type of cardiac capture as being only ventricular myocardial capture in response to at least the far field cardiac electrical signal feature being greater than the non-selective His bundle capture threshold.

2. The system of claim 1 , wherein the control circuit is further configured to:
determine the type of cardiac capture as being selective His bundle capture that includes capture of only the His bundle in response to the time interval being greater than the first time interval threshold.

3. The system of claim 1 , wherein the control circuit is further configured to:
compare the time interval to a second time interval threshold greater than the first time interval threshold; and
determine loss of ventricular capture in response to the time interval being greater than the second time interval threshold.

4. The system of claim 1 , wherein the control circuit is further configured to:
compare the time interval to an expected atrioventricular conduction time range; and
detect atrial capture in response to the time interval being in the expected atrioventricular conduction time range.

5. The system of 4 , wherein the control circuit is further configured to provide an atrial capture response in response to detecting atrial capture, the atrial capture response comprising at least one of:
adjusting a ventricular pacing control parameter; and
generating an atrial capture notification.

6. The system of claim 1 , wherein the control circuit is further configured to:
control the therapy delivery circuit to deliver a plurality of His bundle pacing pulses comprising a plurality of pacing pulse energies;
determine a non-selective His bundle capture threshold from among the plurality of pacing pulse energies based on QRS signals detected from at least the far field cardiac electrical signal following each one of the plurality of His bundle pacing pulses; and
control the therapy delivery circuit to deliver non-selective His bundle pacing pulses each having a pacing pulse energy greater than the non-selective His bundle capture threshold.

7. The system of claim 1 , wherein the control circuit is further configured to:
compare the determined type of cardiac capture to an expected type of cardiac capture; and
in response to the determined type of cardiac capture being different than the expected type of cardiac capture, perform a capture threshold test.

8. The system of claim 1 , wherein the control circuit is further configured to perform a His bundle capture threshold test by:
controlling the therapy delivery circuit to deliver a plurality of His bundle pacing pulses comprising a plurality of pacing pulse energies;
determining the type of capture as being non-selective His bundle capture following at least one of the plurality of His bundle pacing pulses;
determining a non-selective His bundle capture threshold as a lowest one of the plurality of pacing pulse energies for which the type of capture is determined to be non-selective His bundle capture;
determining a first one of ventricular myocardial capture and selective His bundle capture evoked by one of the plurality of His bundle pacing pulses delivered at a next lower one of the plurality of pacing pulse energies that is less than the non-selective His bundle capture threshold;
determining a loss of the second one of the ventricular myocardial capture and selective His bundle capture in response to determining the first one of ventricular myocardial capture and selective His bundle capture evoked by the next lower one of the plurality of pacing pulse energies;
determining a second capture threshold for the second one of the ventricular myocardial capture and selective His bundle capture as being equal to the non-selective His bundle capture threshold; and
determining a first capture threshold for the first one of the ventricular myocardial capture and selective His bundle capture as being a lowest one of the plurality of pacing pulse energies evoking the first one of the ventricular myocardial capture and selective His bundle capture.

9. The system of claim 8 , wherein the control circuit is further configured to:
select a pacing type from a plurality of pacing types comprising at least non-selective His bundle pacing and selective His bundle pacing based on the first capture threshold and the second capture threshold; and
set at least one of a pacing pulse amplitude and a pacing pulse width based on the selected pacing type.

10. The system of claim 1 , wherein the control circuit is further configured to:
determine a non-selective His bundle capture threshold;
compare the non-selective His bundle capture threshold to a maximum limit; and
control the therapy delivery circuit to deliver His bundle pacing pulses having a pacing pulse energy that is greater than the non-selective His bundle capture threshold in response to the non-selective His bundle capture threshold being less than the maximum limit.

11. The system of claim 10 , wherein the control circuit is further configured to:
control the therapy delivery circuit to deliver one of ventricular myocardial pacing and selective His bundle pacing comprising His bundle pacing pulses having a pacing pulse energy that is less than the non-selective His bundle capture threshold in response to the non-selective His bundle capture threshold being greater than the maximum limit.

12. The system of claim 1 , further comprising a power source including at least one battery;
wherein the control circuit is further configured to:
determine a pacing capture threshold that includes His bundle capture;
determine an expected battery longevity based on the pacing capture threshold;
compare the expected battery longevity to a minimum longevity; and
control the therapy delivery circuit to deliver His bundle pacing using a pacing pulse energy greater than the pacing capture threshold that includes His bundle capture in response to the expected battery longevity being greater than the minimum longevity.

13. The system of claim 1 , further comprising:
an implantable power source including at least one battery;
an implantable telemetry circuit; and
an external

Assignees

• Medtronic Inc

Inventors

• Sheldon Todd J
• Campbell Shawn M
• Lybarger Maureen E
• Mattson Elizabeth A
• Williams Eric R
• Yang Zhongping

Classifications

• A61B5/366

  Detecting abnormal QRS complex, e.g. widening · CPC title

• A61B5/363

  Detecting tachycardia or bradycardia · CPC title

• A61B5/361

  Detecting fibrillation · CPC title

• A61B5/283

  Invasive · CPC title

• A61N1/365

  controlled by a physiological parameter, e.g. heart potential {(evoked response A61N1/371)} · CPC title