Characterization of supraventricular rhythm using collected cardiac beats

• US 20040082973A1
• Filed: 10/23/2002
• Published: 04/29/2004
• Est. Priority Date: 10/23/2002
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Bocek, Joseph, Kim, Jaeho
• Granted Patent: US 7,085,599 B2
• Time in Patent Office: Days
• US Class Current: 607/9
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions

Abstract

The supraventricular rhythm of a patient'"'"'s heart is characterized using cardiac beats collected during a plurality of time periods, some of which are noncontiguous. Pacing parameters may be modified to allow the development of a spontaneous rhythm. According to various aspects of the invention, waveforms of the collected cardiac beats are stored for later processing, or are combined with previously collected beats and the combination is stored. When a sufficient number of cardiac beats are collected, the patient'"'"'s supraventricular rhythm is characterized using the collected cardiac beats.

Claims

1. A method for characterizing a patient'"'"'s supraventricular rhythm, comprising:

collecting cardiac beats representative of the patient'"'"'s supraventricular rhythm during a plurality of periods, of which some are noncontiguous; and

characterizing the patient'"'"'s supraventricular rhythm using the collected cardiac beats.

2. The method of claim 1, wherein collecting the cardiac beats comprises storing the cardiac beats.

3. The method of claim 1, wherein collecting the cardiac beats comprises combining each cardiac beat with previously collected cardiac beats and storing the result of the combination.

4. The method of claim 3, wherein combining each cardiac beat with previously collected cardiac beats comprises performing point-by-point addition of a cardiac beat waveform to a template waveform.

5. The method of claim 1, wherein collecting the cardiac beats comprises:

modifying a pacing parameter; and

collecting the cardiac beats during a time in which the pacing parameter is modified.

6. The method of claim 5, wherein collecting the cardiac beats further comprises returning the pacing parameter to an original value.

7. The method of claim 5, wherein modifying the pacing parameter comprises modifying a pacemaker mode.

8. The method of claim 5, wherein modifying the pacing parameter comprises modifying a pacing rate.

9. The method of claim 5, wherein modifying the pacing parameter comprises modifying a pacing interval.

10. The method of claim 5, wherein modifying the pacing parameter comprises suspending one or more pacemaker functions.

11. The method of claim 5, wherein modifying the pacing parameter comprises increasing a pacing escape interval.

12. The method of claim 5, wherein modifying the pacing parameter comprises increasing an AV interval.

13. The method of claim 5, wherein modifying the pacemaker parameter comprises changing a pacemaker mode from a tracking, rate responsive mode to a non-tracking, non-rate responsive mode.

14. The method of claim 5, wherein collecting the cardiac beats during a time in which the pacing parameter is modified comprises collecting the cardiac beats during periodic sessions in which the pacing parameter is modified.

15. The method of claim 14, wherein the periodic sessions in which the pacing parameter is modified occur every 32 to 1024 beats.

16. The method of claim 5, wherein modifying the pacing parameter comprises modifying the pacing parameter to a pacing parameter limit.

17. The method of claim 5, wherein modifying the pacing parameter comprises:

increasing an AV interval;

modifying a pacemaker mode if no intrinsic beats are detected during a period having the increased AV interval; and

slowing a pacing rate to allow intrinsic beats to develop.

18. The method of claim 5, wherein modifying the pacing parameter comprises switching a pacemaker mode from a dual chamber mode to a single chamber mode.

19. The method of claim 5, wherein modifying the pacing parameter comprises:

modifying a pacing mode;

gradually decreasing a pacing rate; and

extending an AV interval.

20. The method of claim 5, wherein modifying the pacing parameter comprises suspending left side pacing.

21. The method of claim 1, wherein characterizing the patient'"'"'s supraventricular rhythm comprises characterizing the patient'"'"'s supraventricular rhythm after a predetermined number of cardiac beats has been collected.

22. The method of claim 21, wherein the predetermined number is about 16.

23. The method of claim 1, wherein characterizing the patient'"'"'s supraventricular rhythm, further comprises:

providing a plurality of templates;

selectively updating the plurality of templates using a plurality of the cardiac beats; and

characterizing the patient'"'"'s supraventricular rhythm using a particular template of the plurality of updated templates.

24. The method of claim 23, wherein updating the plurality of templates further comprises:

detecting a particular cardiac beat of the plurality of cardiac beats;

determining if the particular cardiac beat is correlated to one of the plurality of templates; and

updating the template correlated to the particular cardiac beat.

25. The method of claim 24, wherein detecting the particular cardiac beat comprises:

sensing rate channel signals;

sensing shock channel signals; and

determining if the rate channel signals and the shock channel signals meet predetermined criteria.

26. The method of claim 24, wherein determining if the particular cardiac beat is correlated to one of the plurality of templates further comprises:

identifying a plurality of features of the template;

aligning the shock channel signal of the particular cardiac beat and the template using a fiducial point of the template and a fiducial point of the shock channel signal of the particular cardiac beat;

identifying a plurality of features of the shock channel signal of the particular cardiac beat; and

using the plurality of features of the template and the plurality of features of the particular cardiac beat to determine if the beat is correlated to the template.

27. A body implantable system for characterizing a patient'"'"'s supraventricular rhythm, comprising:

a lead system, the lead system comprising electrodes extending into a heart;

a detector system coupled to the lead system, the detector system configured to detect cardiac beats; and

a control system coupled to the detector system, the control system configured to control pacing of the patient'"'"'s heart, collect the cardiac beats representative of the patient'"'"'s supraventricular rhythm during a plurality of periods, of which some are noncontiguous, and characterize the patient'"'"'s supraventricular rhythm using the collected cardiac beats.

28. The system of claim 27, wherein the control system is configured to modify pacing parameters and collect the cardiac beats representative of the patient'"'"'s supraventricular rhythm during a time in which the pacing parameters are modified.

29. The system of claim 27, wherein the control system is configured to modify one or more pacing parameters including a pacemaker mode, a pacing rate, a pacing interval, and a pacemaker function.

30. The system of claim 29, wherein the control system is configured to store waveforms of the cardiac beats.

31. The system of claim 27, wherein the control system is configured to combine a waveform of each collected cardiac beat with waveforms of previously collected cardiac beats and to store the result of the combination.

32. The system of claim 27, wherein the control system is configured to combine a waveform of each collected cardiac beat with waveforms of previously collected cardiac beats by adding the waveform to a template waveform.

33. The system of claim 27, wherein the detector system comprises at least one rate channel amplifier coupled to the control system, the control system modifying a gain of the at least one rate channel amplifier during characterization of the patient'"'"'s supraventricular rhythm.

34. The system of claim 33, wherein the gain of the at least one rate channel amplifier is not modified in response to a ventricular paced beat unless N consecutive pacing pulses have occurred since a last intrinsic ventricular beat.

35. The system of claim 34, wherein N=1, 2 or 3.

36. A system for characterizing a patient'"'"'s supraventricular rhythm,

comprising:

means for collecting cardiac beats during a plurality of periods, of which some are noncontiguous; and

means for characterizing the patient'"'"'s supraventricular rhythm using the collected cardiac beats.

37. The system of claim 36, further comprising means for modifying pacing parameters.

38. The system of claim 37, wherein means for collecting the cardiac beats comprises means for collecting the cardiac beats during a time in which the pacing parameters are modified.