Apparatus And Method For Analyzing Patient Tolerance To A Stimulation Mode Favoring A Spontaneous Atrioventricular Conduction

• US 20100318150A1
• Filed: 06/11/2010
• Published: 12/16/2010
• Est. Priority Date: 06/15/2009
• Status: Active Grant

• Current Assignee: Sorin CRM USA (MicroPort Scientific Corp.)
• Original Assignee: Sorin CRM USA (MicroPort Scientific Corp.)
• Inventors: GRAINDORGE, Laurence
• Granted Patent: US 8,874,210 B2
• Time in Patent Office: Days
• US Class Current: 607/18
• CPC Class Codes: A61N 1/365 controlled by a physiological parameter, e.g. heart potential evoked response A61N1/371
• CPC Class Codes: A61N 1/36514 controlled by a physiological quantity other than heart potential, e.g. blood pressure controlled by two or more physical parameters A61N1/36585
• CPC Class Codes: A61N 1/36521 the parameter being derived from measurement of an electrical impedance
• CPC Class Codes: A61N 1/36528 the parameter being measured by means of ultrasound
• CPC Class Codes: A61N 1/36542 controlled by body motion, e.g. acceleration
• CPC Class Codes: A61N 1/36557 controlled by chemical substances in blood
• CPC Class Codes: A61N 1/36564 controlled by blood pressure
• CPC Class Codes: A61N 1/36578 controlled by mechanical motion of the heart wall, e.g. measured by an accelerometer or microphone
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters
• CPC Class Codes: A61N 1/3688 configured for switching the pacing mode, e.g. from AAI to DDD
• CPC Class Codes: A61N 1/3918 characterised by shock pathway, e.g. by electrode configuration
• CPC Class Codes: A61N 1/39622 Pacing therapy
• CPC Class Codes: G06T 15/04 Texture mapping

Abstract

An implantable cardiac prosthesis device conducting an analysis of a patient tolerance to a pacing mode favoring the spontaneous atrioventricular conduction is disclosed. The 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.

Claims

1. An active implantable medical device for stimulation, resynchronization and/or defibrillation of a patient, comprising:

means for detecting spontaneous atrial and ventricular events;

means for delivering ventricular and atrial stimulation;

means for detecting spontaneous ventricular depolarization (R) after an atrial pacing (A);

means for measuring an atrioventricular delay (AVD) between the atrial pacing (A) and the corresponding ventricular depolarization (R);

means for operating the device in a dual chamber mode with ventricular sensing and ventricular pacing in the absence of spontaneous ventricular depolarization detected after an atrioventricular delay (AVD);

means for mode switching, to control conditionally, according to a predetermined criteria, the switching of the device between a dual chamber mode and a pacing mode favoring a spontaneous atrioventricular conduction;

a hemodynamic sensor having an output signal;

means for deriving from the output signal a hemodynamic index (Indice_EA_encours) representative of a patient'"'"'s tolerance to the spontaneous atrioventricular conduction; and

means for inhibiting or forcing said conditional switching of the device to the dual chamber mode based on said hemodynamic index.

2. The device of claim 1, wherein the pacing mode favoring the spontaneous atrioventricular conduction to the dual chamber mode comprises an AAI mode having a ventricular detection.

3. The device of claim 1, wherein the pacing mode favoring the spontaneous atrioventricular conduction to the dual chamber mode is one of a DDD mode and a biventricular mode having hysteresis of the atrioventricular delay.

4. The device of claim 1, further comprising means for diagnosing an occurrence of an atrioventricular block, wherein the means for inhibiting or forcing said conditional switching of the device to the dual chamber mode is selectively activated in the absence of atrioventricular block proved by the means for diagnosing.

5. The device of claim 1, further comprising:

means for evaluating a current value of the interval AR (AR₁, AR₂) between the atrial pacing (A) and the consecutive spontaneous ventricular depolarization (R); and

means for comparing said current value of the interval AR to a first threshold (MaxARhemo), wherein the means for inhibiting or of forcing the conditional switching of the device to the dual chamber mode is selectively activated in response to the current value of the interval AR being greater than the first threshold.

6. The device of claim 5, wherein the first threshold (MaxARhemo) further comprises a variable threshold, depending on the heart rate (F_c) of the patient, and the device further comprising means for dynamically reducing the value of the first threshold when the current heart rate is increased.

7. The device of claim 1, further comprising means for detecting of a state of patient effort, wherein the means for inhibiting or forcing of the conditional switching of the device to the dual chamber mode further comprises means for forcing a switch to the dual chamber mode, and inhibiting a return back to the pacing mode favoring the spontaneous atrioventricular conduction until the device detects a state of patient effort.

8. The device of claim 1, wherein the means for inhibiting or forcing the conditional switching of the device to the dual chamber mode, further comprises means for comparing the current value of the hemodynamic index (Indice_EA_encours) to a hemodynamic index of reference (Indice_EA_ref_encours), wherein the means for forcing switches the device to the dual chamber mode when the current value of the hemodynamic index is less than the reference hemodynamic index.

9. The device of claim 8, wherein the value of the reference hemodynamic index (EA_ref) is a variable value depending on the heart rate (F_c) of the patient, and the device further comprises means for dynamically increasing of the value of the reference hemodynamic index when the current heart rate is increased.

10. The device of claim 9, wherein the value of the reference hemodynamic index (EA_ref) is a variable value between a minimum limit (Indice_EA_ref_repos) and a maximum limit (Indice_EA_ref_exer), and the device further comprises means for dynamically updating said minimum and maximum limits.

11. The device of claim 8, further comprising:

means for determining an occurrence of a permanent atrioventricular block, and

means for forcing the reference hemodynamic index (EA_ref) to a value independent of the heart rate in the presence of a determined permanent atrioventricular block.

12. 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.

13. The device of claim 12, wherein the hemodynamic sensor is a hemodynamic endocardial acceleration sensor, delivering the output signal representative of the movements produced by the cyclical contractions of the myocardium.

14. The device of claim 13, further comprising:

means for recognizing and isolating in the output signal a component corresponding to a peak endocardial acceleration associated with the ventricular contraction, and

means for deriving said hemodynamic index from said component.

15. The device of claim 13, further comprising:

means for recognizing and isolating in the output signal delivered by the hemodynamic sensor at least two components (T_1EA, T_2EA) corresponding to two respective peaks of endocardial acceleration associated with the ventricular contraction, and

means for deriving said hemodynamic index from a time interval (Δ

Tx,) separating the at least two components.

16. The device of claim 1, wherein said dual chamber mode comprises a DDD mode.

17. The device of claim 1, wherein said dual chamber mode comprises a biventricular mode.