Frequency domain monitoring of myocardial electrical stability

• US 8,630,701 B2
• Filed: 08/28/2009
• Issued: 01/14/2014
• Est. Priority Date: 02/14/2006
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Wirasinghe, Rushani, Farazi, Taraneh Ghaffari
• Primary Examiner(s): Bertram, Eric D.
• Assistant Examiner(s): Dinga, Roland
• Application Number:
  US12/549,723
• Publication Number:
  US 20100036271A1
• Time in Patent Office: 1,600 Days
• Field of Search: 600/372, 600/375, 600/509, 600/510, 600/513, 600/515, 600/516, 600/517, 600/519, 607/9
• US Class Current: 600/515
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61N 1/3621 for treating or preventing abnormally high heart rate

Abstract

Embodiments of the present invention relate to implantable systems, and methods for use therewith, for monitoring myocardial electrical stability. A patient'"'"'s heart is paced for a period of time using a patterned pacing sequence that repeats every N beats, and an electrical signal is obtained that is representative of a plurality of consecutive beats of the patient'"'"'s heart while it is being paced using the patterned pacing sequence that repeats every N beats. Myocardial electrical stability is then analyzed using frequency domain techniques that are tailored to the patterned pacing sequence used to pace the patient'"'"'s heart. In other embodiments, the patient'"'"'s heart need not be paced. This abstract is not intended to be a complete description of, or limit the scope of, the invention.

Claims

1. A method for detecting an N beat alternans pattern from an electrical signal representative of a plurality of consecutive beats, where N is an integer that is at least 3, the method comprising:

(a) dividing the plurality of consecutive beats into a plurality of sets of N consecutive beats;

(b) for each set of N consecutive beats, selecting 2 of the N beats to produce a sub-set of 2 beats per set of N consecutive beats;

(c) transforming time domain data, associated with the plurality of sub-sets of 2 beats, to frequency domain data; and

(d) determining, based on the frequency domain data, whether electrical alternans are present.

2. The method of claim 1, wherein step (d) includes:

determining, based on the frequency domain data, an alternans magnitude at 0.5 cycles/beat; and

determining, based on the alternans magnitude at 0.5 cycles/beat, whether electrical alternans are present.

3. The method of claim 1, wherein the selecting 2 of the N beats, for each set of N consecutive beats at step (b), comprises selecting 2 consecutive beats from each set of N beats.

4. The method of claim 3, wherein the selecting 2 of the N beats, for each set of N consecutive beats at step (b), comprises selecting the first 2 beats from each set of N beats.

5. A system for detecting an N beat alternans pattern from an electrical signal representative of a plurality of consecutive beats, where N is an integer that is at least 3, the method comprising:

means for dividing the plurality of consecutive beats into a plurality of sets of N consecutive beats;

means for selecting 2 of the N beats to produce a sub-set of 2 beats per set of N consecutive beats, for each set of N consecutive beats;

means for transforming time domain data, associated with the plurality of sub-sets of 2 beats, to frequency domain data; and

means for determining whether electrical alternans are present, based on the frequency domain data.

6. The system of claim 5, wherein the means for determining:

determines, based on the frequency domain data, an alternans magnitude at 0.5 cycles/beat; and

determines, based on the alternans magnitude at 0.5 cycles/beat, whether electrical alternans are present.

7. The system of claim 5, wherein the means for selecting selects 2 consecutive beats from each set of N beats.

8. The system of claim 7, wherein the means for selecting selects the first 2 beats from each set of N beats.

9. A system for monitoring myocardial electrical stability, comprising:

one or more pulse generator configured to pace a patient'"'"'s heart for a period of time using a patterned pacing sequence that repeats every N beats, where N is an integer that is at least 3;

one or more sensing circuit configured to obtain an electrical signal that is representative of a plurality of consecutive beats of the patient'"'"'s heart while the patient'"'"'s heart is being paced using the patterned pacing sequence that repeats every N beats; and

a controller configured to

divide the plurality of consecutive beats into a plurality of sets of N consecutive beats;

select 2 of the N beats, for each set of N consecutive beats, to produce a sub-set of 2 beats per set of N consecutive beats;

transform time domain data, associated with the plurality of sub-sets of 2 beats, to frequency domain data; and

determine, based on the frequency domain data, whether electrical alternans are present.

10. The system of claim 9, wherein the control is configured to

determine, based on the frequency domain data, an alternans magnitude at 0.5 cycles/beat;

and

determine whether electrical alternans are present, based on the alternans magnitude at 0.5 cycles/beat.

11. The system of claim 9, wherein the controller selects 2 of the N beats, for each set of N consecutive beats, by selecting 2 consecutive beats from each set of N beats.

12. The system of claim 11, wherein the controller selects 2 of the N beats, for each set of N consecutive beats, by selecting the first 2 beats from each set of N beats.