Method and system for treatment of neurocardiogenic syncope

• US 8,498,703 B2
• Filed: 09/19/2011
• Issued: 07/30/2013
• Est. Priority Date: 07/27/2001
• Status: Expired due to Term

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Zhu, Qingsheng, Spinelli, Julio C.
• Primary Examiner(s): Holmes, Rex R
• Application Number:
  US13/235,599
• Publication Number:
  US 20120010678A1
• Time in Patent Office: 680 Days
• Field of Search: 607 4- 5, 607/9, 607/23, 607 17- 18, 607/238
• US Class Current: 607/9
• 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 1/36564 controlled by blood pressure

Abstract

A method and apparatus for treating or preventing neurocardiogenic syncope is disclosed. Upon detection of bradycardia or a drop in blood pressure indicating the onset of syncope, electrostimulation pulses are delivered during the heart'"'"'s refractory period. The pulses are non-excitatory but increase myocardial contractility and thereby increase cardiac output.

Claims

1. A method for operating a cardiac stimulator, comprising:

(a) monitoring a heart rate;

(b) detecting an indication of the onset of a syncopal episode, based on said monitoring;

(c) in response to said detecting, initiating delivery of one or more electro-stimulation pulses to a heart, timed to be delivered during a refractory period of the site to which they are applied, in a manner which at least partly alleviates or avoids syncope, wherein said delivery includes the delivery of nonexcitatory electric energy to the heart for the purpose of cardiac contractility modulation;

(d) repeating said detecting;

(e) repeating said initiating based on said repeated detection; and

(f) terminating delivery of said pulses after said detecting indicates no syncopal episode.

2. A method according to claim 1, wherein the method further comprises pacing said heart and wherein said delivery is not done on beats that are paced.

3. A method according to claim 1, comprising increasing a cardiac output of said heart by said one or more electro-stimulation pulses.

4. A method according to claim 1, wherein the method further comprises pacing said heart and wherein a same channel is used for pacing and for said delivery.

5. A method according to claim 1, wherein said delivery comprises delivery to multiple sites in the heart.

6. A method according to claim 1, wherein said detecting comprises detecting a reduction in blood pressure.

7. A method according to claim 1, wherein said detecting comprises detecting a reduction in heart rate.

8. A method according to claim 1, comprising pacing said heart to increase a ventricular contraction rate thereof.

9. A method according to claim 1, comprising applying a hysteresis factor to modify detection of syncope while said electro-stimulation is being delivered.

10. A method according to claim 1, comprising modifying one or both of an intensity and duration of said delivery in response to a measured blood pressure.

11. A method according to claim 10, comprising measuring said blood pressure using an accelerometer.

12. A method according to claim 1, wherein said timed delivery comprises delivering said one or more pulses following and timed to the application of a pacing pulse.

13. A method according to claim 1, wherein said timed delivery comprises delivering said one or more pulses following and timed to a ventricular sense.

25. A method according to claim 1, wherein initiating delivery of one or more electro-stimulation pulses to a heart is only in response to said detecting.

26. A method according to claim 1, wherein said delivery causes an increase in intracellular calcium concentration.

27. A method according to claim 1, wherein detecting an indication of the onset of a syncopal episode comprises detecting a drop in (LV) blood pressure.

14. A cardiac stimulator comprising:

(a) one or more sensing channels configured to monitor a heart rate and to detect an indication of the onset of a syncopal episode, based on the monitoring;

(b) a stimulation channel adapted to deliver one or more electro-stimulation pulses suitable to increase cardiac contractility when delivered during a refractory period of cardiac tissue to which they are delivered; and

(c) a controller configured to

(i) determine one or both of bradycardia and syncope based on input from said sensing channel;

(ii) initiate delivery of said one or more pulses on said channel, based on said determination, at a timing which is during a refractory period for sites to which pulses are delivered, wherein said delivery includes the delivery of non-excitatory electric energy to the heart for the purpose of cardiac contractility modulation; and

(iii) terminate delivery of said one or more pulses based on a determination of no bradycardia or no syncope.

15. A stimulator according to claim 14, integrated into a pacemaker.

16. A stimulator according to claim 14, formed as a stand-alone device.

17. A stimulator according to claim 14, wherein said stimulation channel is shared by pacing and non-pacing signals.

18. A stimulator according to claim 14, wherein said sensing channel is shared by pacing logic and logic for delivery of non-excitatory signals of said controller.

19. A stimulator according to claim 14, comprising electrodes connected to multiple delivery sites in the heart.

20. A Stimulator according to claim 14, wherein said controller is configured to modify one or both of an intensity and duration of said delivery in response to a measured blood pressure.

21. A Stimulator according to claim 14, wherein said controller is configured to calculate a timing based on an incoming sensing.

22. A Stimulator according to claim 14, wherein said controller is configured to calculate a timing based on the timing of an outgoing pacing signal.

23. A Stimulator according to claim 14, wherein said controller is configured to determine one or both of bradycardia and syncope based on comparing input from said sensing channel with a bradycardia or syncope specified threshold.

24. A Stimulator according to claim 14, wherein said controller is configured to initiate delivery of said one or more pulses on said channel only based on said determination.

28. A stimulator according to claim 14, wherein said one or more sensing channels are configured to detect a drop in (LV) blood pressure, and wherein said controller is configured to determine syncope based on said detection of drop in (LV) blood pressure.