Ensemble averaging for evoked responses

• US 7,286,874 B1
• Filed: 09/17/2003
• Issued: 10/23/2007
• Est. Priority Date: 09/17/2003
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Bornzin, Gene A.
• Primary Examiner(s): Layno; Carl
• Assistant Examiner(s): JOHNSON, SHEVON ELIZABETH
• Application Number:
  US10/667,112
• Time in Patent Office: 1,497 Days
• Field of Search: 607/9, 607/17, 607/27, 607/28, 600/509, 600/554
• US Class Current: 607/17
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61N 1/371 Capture, i.e. successful stimulation
• CPC Class Codes: A61N 1/3712 Auto-capture, i.e. automatic adjustment of the stimulation threshold
• CPC Class Codes: A61N 1/3716 with reduction of residual polarisation effects

Abstract

Exemplary methods and devices for analyzing intracardiac electrocardiograms (IEGMs) using ensemble averaging and/or an ensemble average. Various methods and/or devices are suitable for use with atrial and/or ventricular autocapture. Other methods, devices and/or systems are also disclosed.

Claims

1. A method comprising:

delivering a first stimulus to a heart chamber and acquiring an intracardiac electrocardiogram that includes an evoked response;

delivering a second stimulus to the heart that does not capture the heart, and acquiring an intracardiac electrocardiogram that includes an afterpotential;

repeating the delivering of a first stimulus and the acquiring of an intracardiac electrocardiogram that includes an evoked response one or more times; and

generating an ensemble average based on the intracardiac electrocardiograms that include evoked responses and that include an afterpotential.

2. The method of claim 1 wherein the delivering delivers an atrial stimulus and the acquiring acquires an atrial intracardiac electrocardiogram that includes an atrial evoked response.

3. The method of claim 1 wherein the delivering delivers a ventricular stimulus and the acquiring acquires a ventricular intracardiac electrocardiogram that includes a ventricular evoked response.

4. The method of claim 1, wherein the generating comprises subtracting the intracardiac electrocardiogram that includes an afterpotential and no evoked response from one or more of the intracardiac electrocardiogram that include an evoked response.

5. A method comprising:

delivering a stimulus to a heart that does not result in capture;

acquiring an intracardiac electrocardiogram responsive to the stimulus that includes an afterpotential;

repeating the delivering and the acquiring one or more times; and

performing an ensemble average of the intracardiac electrocardiograms.

6. The method of claim 5 wherein the delivering delivers an atrial stimulus and the acquiring acquires an atrial intracardiac electrocardiogram.

7. The method of claim 5 wherein the repeating repeats less than approximately 10 times.

8. The method of claim 5 wherein the acquiring follows a blanking period.

9. The method of claim 5 wherein the acquiring occurs within a time window.

10. The method of claim 5 further comprising excluding one or more of the intracardiac electrocardiograms from the performing on the basis of a criterion or criteria.

11. The method of claim 5 further comprising fitting the ensemble average to a model.

12. The method of claim 11 wherein the model includes an exponential.

13. The method of claim 5 further comprising changing power of the intracardiac stimulus.

14. The method of claim 13 wherein the changing follows the performing and further comprises repeating the delivering, the acquiring, the repeating and the performing.

15. The method of claim 13 further comprising analyzing one or more ensemble averages with respect to power of the intracardiac stimulus.

16. A method comprising:

delivering a first stimulus to a heart chamber that results in capture of the heart tissue, and acquiring an intracardiac electrocardiogram that includes an evoked response;

delivering a subthreshold stimulus to the heart, and acquiring an intracardiac electrocardiogram that includes an afterpotential;

repeating the delivering of a first stimulus and the acquiring an intracardiac electrocardiogram that includes an evoked response one or more times; and

generating an ensemble average based on the intracardiac electrocardiograms that include evoked responses and that include an afterpotential.

17. A device comprising:

a lead adapted to contact heart tissue;

a pulse generator adapted to deliver electrical stimulus to the lead; and

a processor programmed to;

control the pulse generator to deliver a plurality of first stimuli through the lead sufficient to capture the heart and at least one second stimulus through the lead insufficient to capture the heart;

acquire a plurality of intracardiac electrocardiograms that include an evoked response;

acquire an intracardiac electrocardiogram that includes an afterpotential; and

generate an ensemble average based on the intracardiac electrocardiograms.

18. A device comprising:

a lead adapted to contact heart tissue;

a pulse generator adapted to deliver electrical stimulus to the lead; and

a processor programmed to;

control the pulse generator to deliver a plurality of stimuli through the lead insufficient to capture the heart;

acquire a plurality of intracardiac electrocardiograms that include an afterpotential; and

ensemble average the intracardiac electrocardiograms.