Implantable medical device for treating cardiac mechanical dysfunction by electrical stimulation

• US 20040049235A1
• Filed: 08/28/2002
• Published: 03/11/2004
• Est. Priority Date: 08/28/2001
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Euler, David A., Havel, William J., Bennett, Tommy D., Deno, D. Curtis, Stein, Paul M.
• Granted Patent: US 7,096,064 B2
• Time in Patent Office: Days
• US Class Current: 607/9
• CPC Class Codes: A61N 1/36031 using physiological parameters for adjustment
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• CPC Class Codes: A61N 1/3625 External stimulators
• 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 1/36585 controlled by two or more physical parameters
• CPC Class Codes: A61N 1/3706 Pacemaker parameters stimulation threshold A61N1/371
• CPC Class Codes: A61N 1/3956 Implantable devices for applying electric shocks to the heart, e.g. for cardioversion

Abstract

The above-described methods and apparatus are believed to be of particular benefit for patients suffering heart failure including cardiac dysfunction, chronic HF, and the like and all variants as described herein and including those known to those of skill in the art to which the invention is directed. It will understood that the present invention offers the possibility of monitoring and therapy of a wide variety of acute and chronic cardiac dysfunctions. The current invention provides systems and methods for delivering therapy for cardiac hemodynamic dysfunction.

Claims

1. A physiologic atrial coordinated pacing method of therapy delivery for a patient having intact AV conduction, comprising the steps of:

delivering electrical stimulation to an atrial chamber or a ventricular chamber of a heart during a refractory and a subsequent non-refractory period of said chambers at a rate slightly above an estimated or actual intrinsic atrial rate of said heart before an intrinsic A-V interval expires.

2. A method according to claim 1, wherein said electrical stimulation is delivered at the rate and following an instrinsic depolarization of the chamber.

3. A method according to claim 1, wherein said instrinsic atrial rate is estimated based upon a relatively stable cardiac rhythm and wherein said stable cardiac rhythm comprises a cardiac rhythm having a maximum value below a maximum threshold and a minimum value above a minimum threshold.

4. A method according to claim 1, further comprising the step of:

initating an electrical atrial pace stimulus if the actual instrinisic atrial rate or estimated instrinsic atrial rate decreases below a lower threshold value.

5. A method according to claim 1, further comprising the step of initating an electrical atrial pace stimulus if the actual instrinisic atrial rate or estimated instrinsic atrial rate decreases at a rate which indicates said rate will likely decrease below a lower threshold value.

6. A method according to claim 1, wherein an electrical atrial pace stimulus is delivered in lieu of a next-expected atrial sense event, based upon a predetermined number of prior cardiac cycles.

7. A method according to claim 1, wherein in the event that no atrial sensed event occurs during a period defined as a prior V(sense)-to-V(sense) period, then withholding therapy delivery for at least the next cardiac cycles or until extrasystole capture is declared.

8. A method according to claim 1, wherein in the event that the intact AV conduction of the patient becomes impaired, further comprising the step of delivering asynchronous electrical stimulation therapy to at least one of said ventricular chambers.

9. A method according to claim 1, further comprising the step of:

delivering at least one non-excitatory stimulation pulses to a portion of cardiac tissue of said heart.

10. A method according to claim 9, wherein said portion of cardiac tissue comprises at least a one of the following:

a portion of a coronary sinus of said heart, a portion of an autonomic nervous system of said heart, a location proximate an autonomic nerve so that norephinephrine is released from said autonomic nerve in response to the delivered at least one non-excitatory stimulation pulse, a portion of subcutaneous tissue of said patient, a portion of epidermis of said patient, a portion of a pericardium of said heart, an interior portion of said chambers, an exterior portion of said heart, a portion of a pericardium of said heart.

11. A method according to claim 10, wherein said stimulation pulses have a predetermined amplitude depending upon whether said pulses are intended to serve as excitatory or non-excitatory pulses.

12. A method according to claim 1, wherein in the event that a safety-based rule precludes delivery of said electrical therapy to a ventricular chamber of said heart, said atrial coordinated pacing therapy is also withheld.

13. A method of therapy delivery involving stimulation of a portion of a sympathetic nervous system of a patient for enhanced cardiac function, without stimulating the cardiac tissue sufficiently to evoke a depolarization of said cardiac tissue, comprising the steps of:

delivering non-excitatory electrical stimulation to at least a portion of a sympathetic nerve disposed in at least a one of the following regions;

a neck region, a chest region, a mediastimum region, a heart region of a patient so that said heart experiences improved mechanical function due at least in part to release of catecholamine substances.

14. A method according to claim 13, wherein said portion of the sympathetic nerve is at least a one of the following:

an ansa subclavia;

a portion of a thoracic sympathetic nerve;

a cardiac plexus;

at least a portion of a one of an unnamed set of cardiac nerves disposed alongside a coronary vessel;

a portion of an inferior cervical cardiac nerve.

15. A method according to claim 13, wherein said non-excitatory electrical stimulation is approximately 0.1 mV delivered for approximately 0.1 msec.

16. A method according to claim 14, wherein said non-excitatory electrical stimulation is delivered periodically or aperiodically.

17. A method according to claim 14, wherein said non-excitatory electrical stimulation is delivered at least approximately once every 10 seconds.

18. A method of safely applying PESP stimulation pulse therapy to a chamber of a heart, comprising the steps of:

confirming that no arrhythmia is occurring for a predetermined number of cardiac cycles of a heart;

delivering a PESP stimulation therapy to a chamber of the heart; and

ceasing delivery of said PESP therapy upon detection of an arrhythmic cardiac cycle.

19. A method according to claim (above), wherein after ceasing delivery of said PESP therapy, further comprising the step of:

implementing a non-PESP therapy to a chamber of the heart.

20. A method for indicating initiation and termination of PESP stimulation therapy for a patient, comprising the steps of:

obtaining a physiologic measurement from a patient indicating possible cardiac hemodynamic dysfunction therapy;

comparing said physiologic measurement with indications for at least one electrical stimulation therapy;

delivering a first of said at least one electrical stimulation therapy;

rechecking said physiologic measurement for improvement; and

discontinuing said therapy when said physiologic measurement exceeds a predetermined threshold for a predetermined period of time.