Methods and systems for trending ST segment changes over time

• US 8,521,267 B1
• Filed: 06/29/2007
• Issued: 08/27/2013
• Est. Priority Date: 06/29/2007
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Jalali, Laleh, Snell, Jay, Bacon, Elizabeth, Hoberman, Katie, Zhu, Bing
• Primary Examiner(s): Layno, Carl H
• Assistant Examiner(s): Stice, Paula J
• Application Number:
  US11/771,660
• Time in Patent Office: 2,251 Days
• Field of Search: 600508-521, 607/525, 607/3, 607 17- 21, 128/696
• US Class Current: 600/516
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/366 Detecting abnormal QRS complex, e.g. widening
• 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: G16H 40/63 for local operation

Abstract

A method and system are provided for trending a coronary burden such as an ischemic burden or acute myocardial infarction (AMI) for a patient. Trending provides obtaining cardiac data over a period of time, identifying the onset and the termination of coronary episodes based on a ST segment variation within the cardiac data, recording coronary burden information, and presenting the coronary burden information to a user. The coronary burden information may include the number of coronary episodes occurring over a period of time, the time duration of the coronary episodes, and the maximum ST segment variations for the coronary episodes that occur over a period of time.

Claims

1. A method for trending ischemia burden for a patient, comprising:

obtaining cardiac data over a period of time;

collecting reference ST segments from the cardiac data;

identifying onset and termination of multiple ischemia episodes based on ST segment variation between the reference ST segments and a measured ST segment within the cardiac data;

analyzing the cardiac data associated with the multiple ischemia episodes to calculate ischemia burden information over the period of time, the ischemia burden information including at least one of;

i) a count of the ischemia episodes over the period of time;

ii) time durations of the ischemia episodes; and

iii) a maximum ST segment variation for each of the multiple ischemia episodes over the period of time;

recording the ischemia burden information; and

presenting the ischemia burden information related to the multiple ischemia episodes as a multi-episode trend over the period of time.

2. The method of claim 1, wherein the ischemia burden information includes a detection log storing at least one of a) most recent ischemic episodes;

b) highest ST segment variation; and

c) longest ST segment variation.

3. The method of claim 1, wherein the ST segment variation represents a variation between one of a) reference and measured ST segment shifts and b) reference and measured ST segment deviations.

4. The method of claim 1, wherein the presenting includes displaying an IEGM signal at a time of a ischemia episode.

5. The method of claim 1, further comprising co-displaying, on a timeline, baseline ST segment variation over a baseline period of time and the ischemia burden information over the period of time.

6. The method of claim 1, further comprising storing an IEGM signal upon detecting onset of the ischemia episode.

7. The method according to claim 1, wherein the ischemia burden information includes at least one of:

ii) the time durations of the ischemia episodes; and

iii) the maximum ST segment variation for each of the ischemia episodes over the period of time.

9. The method of claim 1, wherein the identifying includes statistically determining a variability between the measured ST segment and the reference ST segments for one of ST segment shift and ST segment deviation.

10. The method of claim 1, wherein the presenting includes displaying the multi-episode trend on a timeline as a percentage of time that ischemia episodes occurred per unit of time.

11. The method of claim 1, wherein the presenting includes displaying the multi-episode trend on a timeline as the count of ischemia episodes that occurred per unit of time.

8. A method for trending ischemia burden for a patient, comprising:

obtaining cardiac data over a period of time;

collecting reference ST segments from the cardiac data;

identifying onset and termination of multiple ischemia episodes based on ST segment variation between the reference ST segments and a measured ST segment within the cardiac data;

analyzing the cardiac data associated with the multiple ischemia episodes to calculate ischemia burden information over the period of time, the ischemia burden information including at least one of;

i) a count of the ischemia episodes over the period of time;

ii) time durations of the ischemia episodes; and

iii) a maximum ST segment variation for each of the multiple ischemia episodes over the period of time;

recording the ischemia burden information; and

presenting the ischemia burden information related to the multiple ischemia episodes as a multi-episode trend over the period of time;

wherein the presenting includes displaying a graphical representation, over time, of the ischemic burden information, where the graphical representation has one axis corresponding to time.

12. A system for trending ischemia burden for a patient, comprising:

a detector module configured to obtain cardiac data over a period of time, the detection module collecting reference ST segments from the cardiac data;

a processor module configured to identify an onset and a termination of multiple ischemia episodes based on ST segment variation between the reference ST segments and a measured ST segment within the cardiac data;

the processor module configured to analyze the cardiac data associated with the multiple ischemia episodes to calculate ischemia burden information over the period of time, the ischemia burden information including at least one of;

i) a count of the ischemia episodes over the period of time;

ii) time durations of the ischemia episodes; and

iii) a maximum ST segment variation for each of the multiple ischemia episodes over the period of time;

a memory module configured to record the ischemia burden information; and

a display module configured to present the ischemia burden information related to the multiple ischemia episodes as a multi-episode trend over the period of time.

13. The system according to claim 12, wherein the ischemia burden information includes a detection log storing at least one of a) most recent ischemic episodes;

b) highest ST segment variation; and

c) longest ST segment variation.

14. The system according to claim 12, wherein the ST segment variation represents a variation between one of a) reference and measured ST segment shifts and b) reference and measured ST segment deviations.

15. The system according to claim 12, wherein the display module presents an IEGM signal at a time of a ischemia episode.

16. The system according to claim 12, wherein the display module co-displays, on a timeline, a baseline ST segment variation over a baseline period of time and the ischemia burden information over the period of time.

17. The system according to claim 12, wherein the memory module stores IEGM signal(s) upon detecting an onset of the ischemia episode.

18. The system according to claim 12, wherein the display module presents the multi-episode trend on a timeline as the count of ischemia episodes that occurred per unit of time.

19. The system according to claim 12, wherein the ischemia burden information includes at least one of:

ii) the time durations of the ischemia episodes; and

iii) the maximum ST segment variation for each of the ischemia episodes over the period of time.

21. The system according to claim 12, wherein the detector module statistically determines a variability between the measured ST segment and the reference ST segments for one of ST segment shift and ST segment deviation.

22. The system according to claim 12, wherein the display module presents the multi-episode trend on a timeline as a percentage of time that ischemia episodes occurred per unit of time.

20. A system for trending ischemia burden for a patient, comprising:

a detector module configured to obtain cardiac data over a period of time, the detection module collecting reference ST segments from the cardiac data;

a processor module configured to identify an onset and a termination of multiple ischemia episodes based on ST segment variation between the reference ST segments and a measured ST segment within the cardiac data;

the processor module configured to analyze the cardiac data associated with the multiple ischemia episodes to calculate ischemia burden information over the period of time, the ischemia burden information including at least one of;

i) a count of the ischemia episodes over the period of time;

ii) time durations of the ischemia episodes; and

iii) a maximum ST segment variation for each of the multiple ischemia episodes over the period of time;

a memory module configured to record the ischemia burden information; and

a display module configured to present the ischemia burden information related to the multiple ischemia episodes as a multi-episode trend over the period of time,

wherein the display module presents a graphical representation, over time, of the ischemia burden information.