Dynamic control of overdrive pacing based on degree of randomness within ...

(54) DYNAMIC CONTROL OF OVERDRIVE PACING BASED ON DEGREE OF RANDOMNESS WITHIN HEART RATE

(75) Inventor: Mark W. Kroll, Simi Valley, CA (US)

(73) Assignee: Pacesetter, Inc., Sylmar, CA (US)

( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 70 days.

(21) Appl. No.: 10/017,836

(22) Filed: Dec. 12, 2001

(51) Int. CI.7 A61N 1/365

(52) U.S. C I 607/14

(58) Field of Search 600/300, 515-518;

607/14, 15

(56) References Cited

U.S. PATENT DOCUMENTS

4,712,555 A 12/1987 Thornander et al. .. 128/419 PG

4,940,052 A 7/1990 Mann et al 128/419 PG

4,944,298 A 7/1990 Sholder 128/419 PG

5,042,497 A 8/1991 Shapland 128/696

5,201,321 A 4/1993 Fulton 128/702

5,342,401 A 8/1994 Spano et al 607/5

5,447,520 A 9/1995 Spano et al 607/5

5,466,254 A 11/1995 Helland 607/123

5,476,483 A 12/1995 Bornzin et al 607/17

5,609,158 A 3/1997 Chan 128/705

5,676,690 A 10/1997 Noren 607/9

5,690,688 A 11/1997 Noren et al 607/17

5,730,144 A 3/1998 Katz et al 127/713

5,817,132 A 10/1998 Karagueuzian et al 607/5

6,058,328 A 5/2000 Levine et al 607/14

6,192,273 Bl * 2/2001 Igel et al 607/14

6,308,094 Bl * 10/2001 Shusterman et al 600/516

OTHER PUBLICATIONS

Callaway et al., "Scaling Exponent Predicts Defibrillation Success for Out-of-Hospital Ventricular Fibrillation Cardiac Arrest", Circulation, pp 1656-1661 (Mar. 27, 2001).

Cotton, "Chaos, Other Nonlinear Dynamics Research May Have Answers, Applications for Clinical Medicine", JAMA, vol. 266, No. 1, pp: 12-18 (Jul. 3, 1991).

Klonowski, "Signal and Image Analysis Using Chaos Theory and Fractal Geometry", Machine Graphics & Vision, vol. 9 (1/2), pp: 403^131 (2000).

Kroll et al., "Slope Filtered Pointwise Correlation Dimension Algorithm and Its Evaluation With Prefibrillation Heart Rate Data", Journal of Electrocardiology, vol. 24, Supplement, pp: 97-101 (1991).

Makikallio, et al., "Abnormalities in Beat to Beat Complexity of Heart Rate Dynamics in Patients with a Previous Myocardial Infarction", JACC, vol. 28, No. 4, pp: 1005-1011 (Oct. 1996).

Peng et al., "Quantification of Scaling Exponents and Crossover Phenomena in Nonstationary Heartbeat Time Series", Chaos, vol. 5, No. 1, pp: 82-87 (1995).

Peng et al., "Fractal Analysis Methods", Reprinted from Nonlinear Dynamics, Self-Organization, and Biomedicine, J. Walleczek, ed., Cambridge University Press, (2000).

(List continued on next page.)

Primary Examiner—George R. Evanisko (57) ABSTRACT

A degree of randomness associated with the heart rate of the patient is determined based on an analysis of electrical heart signals. The degree of randomness may be determined, for example, based on a degree of entropy or a chaos dimensionality associated with heart rate. If the degree of randomness falls below a threshold value, indicating that the heart rate may be too coherent, a warning signal is generated indicating a significant risk of onset of a tachyarrhythmia. To prevent the tachyarrhythmia from occurring, overdrive pacing is initiated or, if already initiated, the overdrive pacing is made more aggressive. In a related technique, chaotic pacing is performed to ensure a sufficient heart rate variability.

14 Claims, 6 Drawing Sheets

OTHER PUBLICATIONS

Pincus, "Approximate Entropy as a Measure of System Complexity", Proc. Natl. Acad. Sci. USA, vol. 88, pp: 2297-2301 (Mar. 1991).

Richman et al., "Physiological Time-Series Analysis Using Approximate Entropy and Sample Entropy", Am. J. Physiol. Heart Circ, 278, pp: H2039-H2049 (2000). Vikman, et al., "Altered Complexity and Correlation Properties of R-R Interval Dynamics Before Spontaneous Onset of Paroxsymal Atrial Fibrillation", Circulation, pp: 2079-2084 (Nov. 16, 1999).

Vikman, et al., "Differences in Heart Rate Dynamics Before the Spontaneous Onset of Long and Short Episodes of Paroxysmal Atrial Fibrillation", A.N.E., vol. 6, No. 2, pp: 134-142 (Apr. 2001).

Laitio, et al., "Correlation Properties and Complexity of Perioperative RR-Interval Dynamics in Coronary Artery Bypass Surgery Patients", Anesthesiology, vol. 93, No. 1, pp: 69-80 (Jul. 2000).

* cited by examiner