Safety pacing in multi-site CRM devices

• US 6,480,740 B2
• Filed: 12/26/2000
• Issued: 11/12/2002
• Est. Priority Date: 12/26/2000
• Status: Expired due to Term

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Calkins, Hugh, Stahmann, Jeffrey E., Kramer, Andrew P.
• Primary Examiner(s): LAYNO, CARL HERNANDZ
• Application Number:
  US09/748,721
• Publication Number:
  US 20020082649A1
• Time in Patent Office: 686 Days
• Field of Search: 607/9, 607/25
• US Class Current: 607/9
• 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 1/368 comprising more than one electrode co-operating with different heart regions A61N1/3622, A61N1/3627 take precedence
• 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

Abstract

An apparatus and method for providing pacing pulses to a second site when the pacing pulses are inhibited from being provided to a first site. A first cardiac signal and a second cardiac signal are sensed, where both the first and second cardiac signals include indications of cardiac events. A cardiac rate is determined from the cardiac events in one of the first cardiac signal or the second cardiac signal, and pacing pulses are provided to the first cardiac region in order to maintain the cardiac rate at at least a minimum rate value. A pace protection interval starts when a cardiac event is detected in the first cardiac signal. The pace protection interval inhibits delivery of pacing pulses to the first cardiac region. When pacing pulses to the first cardiac region are inhibited because of the pace protection interval, pacing pulses are provided to the second cardiac region at a safety interval timed from the inhibited pacing pulse to the first cardiac region.

Claims

1. A method, comprising:

sensing a first cardiac signal from a first cardiac region, where the first cardiac signal includes indications of cardiac events;

sensing a second cardiac signal from a second cardiac region, where the second cardiac signal includes indications of cardiac events;

determining a cardiac rate from the cardiac events in one of the first cardiac signal or the second cardiac signal;

providing pacing pulses to the first cardiac region to maintain the cardiac rate at at least a minimum rate value;

starting a pace protection interval for the first cardiac signal after a cardiac event in the first cardiac signal;

inhibiting a pacing pulse to the first cardiac region during the pace protection interval; and

providing the pacing pulse to the second cardiac region at a safety interval timed from the inhibited pacing pulse to the first cardiac region.

2. The method of claim 1, wherein providing the pacing pulse to the second cardiac region includes providing the pacing pulse to the second cardiac region to maintain the cardiac rate at at least the minimum rate value when the pace protection interval inhibits the pacing pulse to the first cardiac region.

3. The method of claim 1, including setting the safety interval timed from the inhibited pacing pulse in the range of zero (0.0) milliseconds to 300 milliseconds.

4. The method of claim 1, wherein providing the pacing pulse to the second cardiac region includes providing the pacing pulse to the second cardiac region after the pace protection interval.

5. The method of claim 1, wherein providing the pacing pulse to the second cardiac region includes providing the pacing pulse to the second cardiac region during the pace protection interval.

6. The method of claim 1, wherein sensing the first cardiac signal and the second cardiac signal includes detecting an intrinsic cardiac event;

starting the pace protection interval in the first cardiac signal includes starting the pace protection interval in the first cardiac signal after the intrinsic cardiac event in the first cardiac signal;

providing pacing pulses to the first cardiac region to maintain the cardiac rate at at least the minimum rate value includes starting a cardiac cycle escape time interval after the intrinsic cardiac event is sensed in the second cardiac signal;

analyzing the second cardiac signal for a subsequent intrinsic cardiac event during the cardiac cycle escape time interval; and

providing the pacing pulse to the second cardiac region at the safety interval timed from the inhibited pacing pulse to the first cardiac region includes providing the pacing pulse to the second cardiac site at the end of the cardiac cycle escape time interval when the subsequent intrinsic cardiac event is not detected in the second cardiac signal during the cardiac cycle escape time interval.

7. The method of claim 1, wherein sensing the first cardiac signal and the second cardiac signal includes identifying a paced cardiac event;

starting the pace protection interval in the first cardiac signal includes starting the pace protection interval in the first cardiac signal after the paced cardiac event in the first cardiac signal;

starting a cardiac cycle escape time interval after the paced cardiac event is identified in the first or second cardiac signal;

analyzing the second cardiac signal for an intrinsic cardiac event during the cardiac cycle escape time interval; and

providing the pacing pulse to the second cardiac region at the safety interval timed from the inhibited pacing pulse to the first cardiac region includes providing the pacing pulse to the second cardiac site at the end of the cardiac cycle escape time interval when the subsequent intrinsic cardiac event is not detected in the second cardiac signal during the cardiac cycle escape time interval.

8. The method of claim 1, wherein sensing the first cardiac signal includes sensing the first cardiac signal from a left ventricular chamber, and wherein sensing the second cardiac signal includes sensing the second cardiac signal from a right ventricular chamber.

9. The method of claim 1, wherein sensing the first cardiac signal includes sensing the first cardiac signal from a right ventricular chamber, and wherein sensing the second cardiac signal includes sensing the second cardiac signal from a left ventricular chamber.

10. The method of claim 1, wherein sensing the first cardiac signal includes sensing the first cardiac signal from a right atrial chamber, and wherein sensing the second cardiac signal includes sensing the second cardiac signal from a left atrial chamber.

11. The method of claim 1, wherein sensing the first cardiac signal includes sensing the first cardiac signal from a left atrial chamber, and wherein sensing the second cardiac signal includes sensing the second cardiac signal from a right atrial chamber.

12. The method of claim 1, wherein sensing the first cardiac signal includes sensing the first cardiac signal from the first cardiac region of a first cardiac chamber, and wherein sensing the second cardiac signal includes sensing the second cardiac signal from the second cardiac region of the first cardiac chamber.

13. The method of claim 1, including delivering a pacing pulse to a first chamber to maintain the cardiac rate at at least the minimum rate value when the pace protection interval does not inhibit the pacing pulse to the first cardiac chamber.

14. The method of claim 1, including programming the pace protection interval in a range of 200 milliseconds to 500 milliseconds.

15. An apparatus, comprising:

a signal generator

a first sensing/pacing electrode adapted for connection to the signal generator;

a second sensing/pacing electrode adapted for connection to the signal generator; and

where the signal generator includes;

a first cardiac signal sensor to sense a first cardiac signal with the first sensing/pacing electrode;

a second cardiac signal sensor to sense a second cardiac signal with the second sensing/pacing electrode;

a cardiac signal analyzer, where the cardiac signal analyzer determines a cardiac rate from the cardiac events in one of the first cardiac signal or the second cardiac signal;

a pacing output, where the pacing output provides pacing pulses to the first sensing/pacing electrode to maintain a cardiac rate at at least a minimum rate value; and

a pace protection circuit, wherein the pace protection circuit starts a pace protection interval for the first cardiac signal after a cardiac event in the first cardiac signal and where the pace protection circuit inhibits pacing pulses from the pacing output to a first cardiac chamber during the pace protection interval, and provides a pacing pulse from the pacing output to the second sensing/pacing electrode at a safety interval timed from the inhibited pacing pulse to the first cardiac chamber.

16. The apparatus of claim 15, wherein the pace protection circuit provides the pacing pulse to the second cardiac region to maintain the cardiac rate at at least the minimum rate value when the pace protection interval inhibits the pacing pulse to the first cardiac region.

17. The apparatus of claim 15, wherein the safety interval is programmed in the range of zero (0.0) milliseconds to 300 milliseconds.

18. The apparatus of claim 15, wherein the pace protection circuit provides the pacing pulse to the second cardiac region after the pace protection interval.

19. The apparatus of claim 15, wherein the pace protection circuit provides the pacing pulse to the second cardiac region during the pace protection interval.

20. The apparatus of claim 15, wherein the cardiac signal analyzer detects an intrinsic cardiac event in the first and second cardiac signals, the pace protection starts the pace protection interval in the first cardiac signal after the intrinsic cardiac event in the first cardiac signal and starts a cardiac cycle escape time interval after the intrinsic cardiac event is sensed in the second cardiac signal, and wherein the cardiac signal analyzer senses for a subsequent intrinsic cardiac event in the second cardiac signal during the cardiac cycle escape time interval, and the pace protection circuit provides a pacing pulse to the second sensing/pacing electrode at the end of the cardiac cycle escape time interval when the subsequent intrinsic cardiac event is not sensed by the cardiac signal analyzer from the second sensing/pacing electrode during the cardiac cycle escape time interval.

21. The apparatus of claim 15, wherein the cardiac signal analyzer identifies a paced cardiac event in the first and second cardiac signals, the pace protection starts the pace protection interval in the first cardiac signal after the paced cardiac event in the first cardiac signal and starts a cardiac cycle escape time interval after the paced cardiac event is identified in the first or second cardiac signal, and wherein the cardiac signal analyzer senses for an intrinsic cardiac event in the second cardiac signal during the cardiac cycle escape time interval, and the pace protection circuit provides a pacing pulse to the second sensing/pacing electrode at the end of the cardiac cycle escape time interval when the subsequent intrinsic cardiac event is not sensed by the cardiac signal analyzer from the second sensing/pacing electrode during the cardiac cycle escape time interval.

22. The apparatus of claim 15, wherein the first cardiac signal sensor senses a unipolar cardiac signal with the first sensing/pacing electrode, and the second cardiac signal sensor senses a unipolar cardiac signal with the second sensing/pacing electrode.

23. The apparatus of claim 15, wherein the first cardiac signal sensor senses a unipolar cardiac signal with the first sensing/pacing electrode, and the second cardiac signal sensor senses a bipolar cardiac signal with the second sensing/pacing electrode.

24. The apparatus of claim 15, wherein the first cardiac signal sensor senses a bipolar cardiac signal with the first sensing/pacing electrode, and the second cardiac signal sensor senses a bipolar cardiac signal with the second sensing/pacing electrode.

25. The apparatus of claim 15, wherein the pace protection circuit provides a pacing pulse to the first sensing/pacing electrode to maintain the cardiac rate at at least the minimum rate value when the pace protection circuit does not inhibit the pacing pulse to the first sensing/pacing electrode.

26. The apparatus of claim 15, wherein the pace protection interval is programmable in a range of 200 milliseconds to 500 milliseconds.