Method and apparatus for treating cardiac arrhythmia using electrogram features

• US 20030187480A1
• Filed: 03/24/2003
• Published: 10/02/2003
• Est. Priority Date: 05/06/1997
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Lin, Yayun, KenKnight, Bruce H., Jones, Janice, Hsu, William
• Granted Patent: US 6,839,591 B2
• Time in Patent Office: Days
• US Class Current: 607/5
• CPC Class Codes: A61N 1/39622 Pacing therapy

Abstract

A method and system for ventricular defibrillation by coordinating the delivery of defibrillation shocks with sensed ventricular fibrillation complexes in a way which improves the probability of success of the defibrillation shock. Ventricular electrical activity is monitored in two ventricular locations during ventricular fibrillation to detect coarse ventricular fibrillation complexes and contractions of the ventricular cardiac tissue. The defibrillation shock is delivered in coordination with the occurrence of coarse ventricular fibrillation complexes and the contractions of ventricular cardiac tissue, and specifically to occur on the up-slope portion thereof, for optimal probability of success.

Claims

1. An apparatus comprising:

a means for monitoring a first cardiac signal across a left ventricular cardiac region;

a detector coupled with the means for monitoring, the detector adapted to detect a contraction of cardiac tissue in the first cardiac signal;

a coupling interval timer that starts once the contraction of tissue is detected;

the coupling interval timer counting a predetermined time period; and

a means for delivering a defibrillation shock during the time period counted by the coupling interval timer.

2. The apparatus as recited in claim 1, further comprising a means for monitoring a second cardiac signal across a right ventricular cardiac region, and the means for delivering a debrillation shock includes a means for delivering the defibrillation shock during the occurrence of the starting of the coupling interval timer and an up-slope portion of a coarse ventricular fibrillation complex as detected by the second cardiac signal.

3. The apparatus as recited in claim 2, further comprising a means for counting coarse ventricular fibrillation complexes detected in the second cardiac signal.

4. The apparatus as recited in claim 1, wherein the means for monitoring the first cardiac signal includes a predetermined threshold value, and the predetermined threshold value is approximately 0.1 to 10 millivolts.

5. The apparatus as recited in claim 1, wherein the detector is an R-wave detector.

6. The apparatus as recited in claim 1, further comprising at least one electrode.

7. The apparatus as recited in claim 6, wherein the at least one electrode includes a tip electrode and a first defibrillation coil electrode.

8. The apparatus as recited in claim 6, wherein the at least one electrode includes at least two electrode having two ventricular pacing locations.

9. The apparatus as recited in claim 1, further comprising a means for delivering pacing level pulses at the left ventricular cardiac region.

10. A method of treating ventricular fibrillation, comprising:

starting a waiting period timer once a ventricular fibrillation has been detected;

monitoring a signal representative of ventricular electrical activity during a period of ventricular fibrillation;

detecting in the monitored signal, the occurrence of coarse ventricular fibrillation complexes;

analyzing coarse ventricular fibrillation to determine upslope; and

delivering a defibrillation shock either during the upslope portion of a coarse ventricular fibrillation complex or at the expiration of the waiting period timer.

11. The method of claim 10, further comprising counting occurrences of coarse ventricular fibrillation complexes, and coordinating the delivery of the defibrillation shock with the upslope of a predetermined numbered occurrence of coarse ventricular fibrillation complex.

12. The method of claim 10, wherein monitoring the signal comprises monitoring the morphology signal, across a first defibrillation coil electrode and a second defibrillation coil electrode of an endocardial lead, and where delivering a defibrillation shock includes applying a pulse of electrical energy to the endocardial lead.

13. The method of claim 10, wherein delivering a defibrillation shock includes applying a pulse of electrical energy between first and second defibrillation coil electrodes.

14. The method of claim 10, wherein detecting and analyzing the occurrence of a coarse ventricular fibrillation complex includes sensing when the amplitude of the ventricular fibrillation signal is greater than a coarse complex threshold value with a positive slope or rate of change.

15. The method of claim 10, wherein delivering a defibrillation shock includes timing the shock based on when the amplitude of the ventricular fibrillation signal is greater than a coarse complex threshold value and has a positive slope or rate of change.

16. The method of claim 10, wherein the waiting period timer is a programmable value within the range of 10-40 seconds.