Stimulation mode determination

Patent metadata

Field	Value
Publication number	US-9504835-B2
Application number	US-201414480855-A
Country	US
Kind code	B2
Filing date	Sep 9, 2014
Priority date	Jun 15, 2009
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

Devices and methods for providing pacing in multiple modes are provided. One device operates in a dual chamber (DDD or biventricular) mode and in a pacing mode favoring the spontaneous atrioventricular conduction such as an AAI mode ( 10 ) with a ventricular sensing or a mode with hysteresis of the atrioventricular delay. The device controls ( 10 - 18 ) the conditional switching from one mode to the other. The device comprises a hemodynamic sensor, including an endocardial acceleration sensor, derives a hemodynamic index representative of the hemodynamic tolerance of the patient to the spontaneous atrioventricular conduction. The device controls inhibiting or ( 20 ) forcing the conditional switching of the device to the DDD (or biventricular) mode according to the evolution of the hemodynamic index.

First claim

What is claimed is:

1. An active implantable medical device for stimulation, resynchronization and/or defibrillation of a patient, comprising:
a hemodynamic sensor configured to generate an output signal; and
one or more circuits configured to:
switch the implantable medical device between a single chamber mode of stimulation and a dual chamber mode of stimulation;
measure the atrioventricular delay between an atrial pacing event and a spontaneous ventricular depolarization after the atrial pacing event;
determine whether the atrioventricular delay exceeds a threshold atrioventricular delay; and
in response to the atrioventricular delay exceeding the threshold atrioventricular delay:
derive from the output signal of the hemodynamic sensor a hemodynamic index representative of a patient's tolerance to the atrioventricular delay that exceeds the threshold atrioventricular delay, wherein the one or more circuits are configured to utilize output data from the hemodynamic sensor associated with a single cardiac cycle to derive the hemodynamic index; and
determine whether to activate or deactivate the dual chamber mode based on the hemodynamic index.

2. The device of claim 1 , wherein the one or more circuits are further configured to:
diagnose an occurrence of an atrioventricular block; and
activate the dual chamber mode in the absence of the atrioventricular block.

3. The device of claim 1 , wherein the threshold atrioventricular delay comprises a variable threshold, depending on the heart rate of the patient, and the one or more circuits are configured to dynamically reduce a value of the variable threshold when the current heart rate is increased.

4. The device of claim 1 , wherein the one or more circuits are configured to:
detect of a state of patient effort; and
force a switch to the dual chamber mode and inhibit a return back to the single chamber mode until the device detects the state of patient effort.

5. The device of claim 1 , wherein the one or more circuits are configured to determine whether to activate or deactivate the dual chamber mode by:
comparing a current value of the hemodynamic index to a reference hemodynamic index; and
activating the dual chamber mode when the current value of the hemodynamic index is less than the reference hemodynamic index.

6. The device of claim 5 , wherein the value of the reference hemodynamic index is a variable value depending on the heart rate of the patient, and the one or more circuits are configured to dynamically increase the value of the reference hemodynamic index when the current heart rate is increased.

7. The device of claim 6 , wherein the value of the reference hemodynamic index is a variable value between a minimum limit and a maximum limit, and the one or more circuits are configured to dynamically update the minimum and maximum limits.

8. The device of claim 5 , wherein the one or more circuits are configured to:
determine an occurrence of a permanent atrioventricular block; and
set the reference hemodynamic index to a value independent of the heart rate in the presence of the determined permanent atrioventricular block.

9. The device of claim 1 , wherein the hemodynamic sensor further comprises a sensor selected from among the group consisting of an endocardial acceleration sensor, an epicardial acceleration sensor, a myocardium wall motion sensor, an intracardiac pressure sensor, an intracardiac bioimpedance sensor, an optical sensor measuring oxygen saturation, and a sensor for measuring a change in volume by ultrasounds.

10. The device of claim 9 , wherein the hemodynamic sensor is a hemodynamic endocardial acceleration sensor configured to generate the output signal representative of the movements produced by cyclical contractions of a myocardium.

11. The device of claim 10 , wherein the one or more circuits are configured to:
recognize and isolate in the output signal a component corresponding to a peak endocardial acceleration associated with a ventricular contraction; and
derive the hemodynamic index from the component.

12. The device of claim 10 , wherein the one or more circuits are configured to:
recognize and isolate in the output signal delivered by the hemodynamic sensor at least two components corresponding to two respective peaks of endocardial acceleration associated with the ventricular contraction; and
derive the hemodynamic index from a time interval separating the at least two components.

13. An implantable medical device comprising:
a hemodynamic sensor configured to generate an output signal, wherein the hemodynamic sensor comprises an electronic sensor configured to measure a value representative of a property of at least one of:
heart tissue; or
blood flowing through a heart or blood vessels proximate to the heart; and one or more circuits configured to:
switch the implantable medical device between a single chamber mode of stimulation and a dual chamber mode of stimulation;
measure the atrioventricular delay between an atrial pacing event and a spontaneous ventricular depolarization after the atrial pacing event;
determine whether the atrioventricular delay exceeds a threshold atrioventricular delay; and
in response to the atrioventricular delay exceeding the threshold atrioventricular delay:
derive from the output signal of the hemodynamic sensor a hemodynamic index representative of a patient's tolerance to the atrioventricular delay that exceeds the threshold atrioventricular delay; and
determine whether to activate or deactivate the dual chamber mode based on the hemodynamic index.

14. The device of claim 13 , wherein the hemodynamic sensor is configured to measure one or more of an endocardial acceleration value, an epicardial acceleration value, a myocardium wall motion value, an intracardiac pressure value, an intracardiac bioimpedance value, an oxygen saturation value, or a volume change value.

15. The device of claim 13 , wherein the threshold atrioventricular delay comprises a variable threshold, depending on the heart rate of the patient, and the one or more circuits are configured to dynamically reduce a value of the variable threshold when the current heart rate is increased.

16. The device of claim 13 , wherein the one or more circuits are configured to determine whether to activate or deactivate the dual chamber mode by:
comparing a current value of the hemodynamic index to a reference hemodynamic index; and
activating the dual chamber mode when the current value of the hemodynamic index is less than the reference hemodynamic index.

17. The device of claim 16 , wherein the value of the reference hemodynamic index is a variable value depending on the heart rate of the patient, and the one or more circuits are configured to dynamically increase the value of the reference hemodynamic index when the current heart rate is increased.

18. The device of claim 17 , wherein the one or more circuits are configured to:
determine an occurrence of a permanent atrioventricular block; and
set the reference hemodynamic index to a value independent of the heart rate in the presence of the determined permanent atrioventricular block.

19. The device of claim 13 , wherein the hemodynamic sensor is a hemodynamic endocardial acceleration sensor configured to generate the output signal representative of the movements produced by cyclical contractions of a myocardium.

20. The device of claim 19 , wherein the one or more circuits are configured to:
recognize and isolate in the output signal

Assignees

• Sorin Crm Sas
• Sorin Crm Sas

Inventors

• Graindorge Laurence

Classifications

• A61N1/365 Primary

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

• A61N1/36557

  controlled by chemical substances in blood · CPC title

• A61N1/36514

  controlled by a physiological quantity other than heart potential, e.g. blood pressure (controlled by two or more physical parameters A61N1/36585) · CPC title

• A61N1/36542

  controlled by body motion, e.g. acceleration · CPC title

• A61N1/36521

  the parameter being derived from measurement of an electrical impedance · CPC title