Cross chamber interval correlation

• US 6,522,917 B1
• Filed: 07/12/2000
• Issued: 02/18/2003
• Est. Priority Date: 04/01/1999
• Status: Expired due to Term

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Sweeney, Robert J., Hsu, William
• Primary Examiner(s): Jastrzab, Jeffrey R.
• Assistant Examiner(s): Oropeza, Frances P.
• Application Number:
  US09/615,014
• Time in Patent Office: 951 Days
• Field of Search: 600/372, 600/373, 600/374, 600/509, 600/513, 600/515, 600/518, 600/519, 600/521, 607/14
• US Class Current: 600/518
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions

Abstract

A system and method for discriminating cardiac rhythms occurring in an antegrade direction from cardiac rhythms occurring in a retrograde direction. Atrial and ventricular contractions are sensed, from which atrial and ventricular cycle lengths are determined. Ventricular contractions are also analyzed to determine the occurrence of a tachycardia episode that has a one-to-one association of atrial contractions to ventricular contractions. During a tachycardia episode having a one-to-one association of atrial contractions to ventricular contractions, the atrial cycle lengths are paired with the ventricular cycle lengths, where for each of the atrial cycle lengths the atrial cycle length is paired with at least one ventricular cycle length started before the first atrial contraction of each of the atrial cycle lengths and paired with at least one ventricular cycle length started after the first atrial contraction of each of the atrial cycle lengths. A retrograde correlation coefficient is then determined for the atrial cycle lengths paired with the ventricular cycle lengths started before the first atrial contraction, and an antegrade correlation coefficient is determined for the atrial cycle lengths paired with the ventricular cycle lengths started after the first atrial contraction. The tachycardiac episode is then classified based on a comparison of the antegrade correlation coefficient and the retrograde correlation coefficient.

Claims

1. A system, comprising:

an atrial lead and a ventricular lead, where the atrial lead includes an atrial pacing/sensing electrode and the ventricular lead includes a defibrillation electrode and a ventricular pacing/sensing electrode;

control circuitry coupled to the atrial pacing/sensing electrode, the defibrillation electrode and the ventricular pacing/sensing electrode, where the control circuitry receives signals indicating atrial contractions and ventricular contractions, and where the control circuitry includes;

a ventricular contraction detector circuit to detect the occurrence of the ventricular contractions;

an atrial contraction detector circuit to detect the occurrence of the atrial contractions;

a cardiac data analyzing circuit coupled to the ventricular contraction detector circuit and the atrial contraction detector circuit, where the cardiac data analyzing circuit calculates atrial cycle lengths from the detected atrial contractions and ventricular cycle lengths from the detected ventricular cycle lengths and analyzes the ventricular contractions for the occurrence of a tachycardia episode, and when the tachycardia episode occurs the cardiac data analyzing circuit analyzes the ventricular contractions and the atrial contractions to determine whether a one-to-one association of atrial contractions to ventricular contractions exists;

a cycle length pairing circuit coupled to the cardiac data analyzing circuit, where the cycle length pairing circuit pairs the atrial cycle lengths and the ventricular cycle lengths in an antegrade direction and a retrograde direction when the cardiac data analyzing circuit determines the tachycardia episode has the one-to-one association of atrial contractions to ventricular contractions; and

a microprocessor coupled to the cycle length pairing circuit, where the microprocessor determines a retrograde correlation coefficient for the atrial cycle lengths paired with the ventricular cycle lengths paired in the retrograde direction and an antegrade correlation coefficient for the atrial cycle lengths paired with the ventricular cycle lengths paired in the antegrade direction, and where the microprocessor classifies the tachycardia episode based on a comparison of the antegrade correlation coefficient and the retrograde correlation coefficient.

2. The system of claim 1, where the microprocessor classifies the tachycardia episode as occurring in the antegrade direction when the antegrade correlation coefficient is greater than the retrograde correlation coefficient.

3. The system of claim 2, where the control circuitry includes a pacing output circuit coupled to the microprocessor, where the pacing output circuit produces pulses with predetermined timing under the control of the microprocessor during the tachycardia episode having the one-to-one association of atrial contractions to ventricular contractions.

4. The system of claim 1, where the cycle length pairing circuit pairs the atrial cycle lengths and the ventricular cycle lengths in a super-antegrade direction and a super-retrograde direction when the cardiac data analyzing circuit determines the tachycardia episode has the one-to-one association of atrial contractions to ventricular contractions;

and

the microprocessor determines a super-retrograde correlation coefficient for the atrial cycle lengths paired with the ventricular cycle lengths paired in the super-retrograde direction and a super-antegrade correlation coefficient for the atrial cycle lengths paired with the ventricular cycle lengths paired in the super-antegrade direction, and where the microprocessor classifies the tachycardia episode based on a comparison of the antegrade correlation coefficient, the retrograde correlation coefficient, the super-retrograde correlation coefficient and the super-antegrade correlation coefficient.

5. The system of claim 4, where the microprocessor classifies the tachycardia episode as occurring in the antegrade direction when the super-antegrade correlation coefficient is greater than the super-retrograde correlation coefficient.

6. The system of claim 5, where the control circuitry includes a pacing output circuit coupled to the microprocessor, where the pacing output circuit produces pulses with predetermined timings under the control of the microprocessor during the tachycardia episode having the one-to-one association of atrial contractions to ventricular contractions.

7. The system of claim 1, where the microprocessor classifies the tachycardia episode as occurring in the retrograde direction when the retrograde correlation coefficient is greater than the antegrade correlation coefficient.

8. The system of claim 3, where the pacing output circuit delivers a series of pacing pulses through the atrial lead, where each pacing pulse of the series of pacing pulses is delivered at a predetermined frequency.

9. The system of claim 8, wherein the predetermined frequency is variable.

10. The system of claim 8, wherein the predetermined frequency is constant.

11. The system of claim 3, where the pacing output circuit delivers a series of pacing pulses through the ventricular lead, where each pacing pulse of the series of pacing pulses is delivered at a predetermined frequency.

12. The system of claim 11, wherein the predetermined frequency is variable.

13. The system of claim 11, wherein the predetermined frequency is constant.

14. The system of claim 4, where the microprocessor classifies the tachycardia episode as occurring in the antegrade direction when the super-antegrade correlation coefficient is greater than the super-retrograde correlation coefficient.

15. The system of claim 4, where the microprocessor classifies the tachycardia episode as occurring in the retrograde direction when the super-retrograde correlation coefficient is greater than the super-antegrade correlation coefficient.

16. The system of claim 6, where the pacing output circuit delivers a series of pacing pulses through the atrial lead, where each pacing pulse of the series of pacing pulses is delivered at a predetermined frequency.

17. The system of claim 16, wherein the predetermined frequency is variable.

18. The system of claim 16, wherein the predetermined frequency is constant.

19. The system of claim 6, where the pacing output circuit delivers a series of pacing pulses through the ventricular lead, where each pacing pulse of the series of pacing pulses is delivered at a predetermined frequency.

20. The system of claim 19, wherein the predetermined frequency is variable.

21. The system of claim 19, wherein the predetermined frequency is constant.