METHOD AND APPARATUS FOR IDENTIFICATION OF ISCHEMIC/INFARCTED REGIONS AND THERAPY OPTIMIZATION

• US 20120277607A1
• Filed: 07/09/2012
• Published: 11/01/2012
• Est. Priority Date: 10/02/2006
• Status: Active Grant

• Current Assignee: Allan C. Shuros, Chris Hartemink, Jiang Ding, Michael J. Stucky, Shantha Arcot-Krishnamurthy, Yinghong Yu
• Original Assignee: Allan C. Shuros, Chris Hartemink, Jiang Ding, Michael J. Stucky, Shantha Arcot-Krishnamurthy, Yinghong Yu
• Inventors: Arcot-Krishnamurthy, Shantha, Shuros, Allan C., Ding, Jiang, Yu, Yinghong, Stucky, Michael J., Hartemink, Chris
• Granted Patent: US 8,489,204 B2
• Time in Patent Office: Days
• US Class Current: 600/509
• CPC Class Codes: A61B 5/02028 Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction
• 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 1/36585 controlled by two or more physical parameters
• 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
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371

Abstract

A method and apparatus is described for detecting and localizing areas of myocardial infarction or ischemia. By pacing sites in proximity to the infarcted or ischemic region with appropriately timed pacing pulses, the region is pre-excited in a manner that lessens the mechanical stress to which it is subjected, thus reducing the metabolic demand of the region and the stimulus for remodeling.

Claims

1. An implantable device, comprising:

pulse generation circuitry for generating pacing pulses;

sensing circuitry for receiving electrogram signals;

a switch matrix for connecting the pulse generation circuitry and/or sensing circuitry to electrodes selected from a plurality of electrodes adapted for disposition at a plurality of sites near different myocardial regions;

a controller interfaced to the sensing circuitry that is programmed to derive one or more characteristics from electrogram signals generated by a plurality of electrodes connected to the sensing circuitry by the switch matrix, wherein the one or more characteristics are locally affected by myocardial ischemia or infarction such that the magnitude of a characteristic derived from a particular electrode varies in relation to the proximity of the particular electrode to an ischemic or infarcted myocardial region;

wherein the controller is programmed to measure the one or more characteristics over time and establish baseline values for the measured characteristics;

wherein the controller is programmed to detect myocardial ischemia/infarction when a deviation from the baseline in one or more characteristics occurs above a specified threshold;

wherein the controller is further programmed to localize an ischemic/infarcted region(s) by analyzing the magnitudes of the measured characteristics as derived from differently located electrodes; and

,

wherein the controller is further programmed to, among the plurality of electrodes connected to the sensing circuitry, identify electrodes in a zone around the ischemic/infarcted region including an electrode having the largest change in characteristics above the baseline.

2. The device of claim 1 wherein the controller is further programmed to deliver pre-excitation pacing through a configured pacing channel to a pacing site in proximity to the ischemic/infarcted region.

3. The device of claim 2 wherein the derived characteristic is an intrinsic activation time defined as the time between an atrial pace or sense and a fiducial point extracted from an electrogram.

4. The device of claim 2 wherein the derived characteristic is an electrogram amplitude.

5. The device of claim 2 wherein the derived characteristic is a time interval between the start of depolarization and the end of repolarization in an electrogram signal.

6. The device of claim 2 wherein the derived characteristic is the duration of depolarization in an electrogram signal.

7. The device of claim 2 wherein the derived characteristic is a morphological feature of the electrogram as detected by correlation with a patient-specific template waveform.

8. The device of claim 2 wherein the derived characteristic is a pacing capture threshold.

9. The device of claim 1 further comprising sensors for detecting myocardial displacement or strain and wherein the controller is programmed to derive a characteristic locally affected by ischemia from the sensors.

10. The device of claim 1 wherein the controller is further programmed to localize an ischemic/infarcted region(s) from the number and location of electrodes exhibiting acute changes as well as the magnitude of the acute changes in each electrode.

11. The device of claim 1 wherein the controller is further programmed to issue an alert by transmission of an alert message to a remote monitor via telemetry upon detection of ischemia/infarction.

12. A method, comprising:

receiving electrogram signals from a plurality of electrodes disposed near different myocardial regions;

deriving one or more characteristics from the electrogram signals, wherein the one or more characteristics are locally affected by myocardial ischemia or infarction such that the magnitude of a characteristic derived from a particular sensor varies in relation to the proximity of the particular electrode to an ischemic or infarcted myocardial region;

measuring the one or more characteristics over time and establish baseline values for the measured characteristics;

detecting myocardial ischemia/infarction when a deviation from the baseline in one or more characteristics occurs above a specified threshold;

localizing an ischemic/infarcted region(s) by analyzing the magnitudes of the measured characteristics as derived from differently located electrodes; and

,

identifying electrodes in a zone around the ischemic/infarcted region including an electrode having the largest change in characteristics above the baseline.

13. The method of claim 12 further comprising configuring a pacing channel with the electrode having the largest change in characteristics above the baseline and delivering pre-excitation pacing to a pacing site in proximity to the ischemic/infarcted region through the configured pacing channel.

14. The method of claim 12 wherein the derived characteristic is an intrinsic activation time defined as the time between an atrial pace or sense and a fiducial point extracted from an electrogram.

15. The method of claim 12 wherein the derived characteristic is an electrogram amplitude.

16. The method of claim 12 wherein the derived characteristic is a time interval between the start of depolarization and the end of repolarization in an electrogram signal.

17. The method of claim 12 wherein the derived characteristic is the duration of depolarization in an electrogram signal.

18. The method of claim 12 wherein the derived characteristic is a morphological feature of the electrogram as detected by correlation with a patient-specific template waveform.

19. The method of claim 12 further comprising localizing an ischemic/infarcted region(s) from the number and location of electrodes exhibiting acute changes as well as the magnitude of the acute changes in each electrode.

20. The method of claim 12 further comprising transmitting an alert message to a remote monitor via telemetry upon detection of ischemia/infarction.