Method and apparatus for diagnosis and treatment of arrhythmias

• US 5,836,975 A
• Filed: 06/05/1997
• Issued: 11/17/1998
• Est. Priority Date: 12/19/1996
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: DeGroot, Paul J.
• Primary Examiner(s): Getzow, Scott M.
• Application Number:
  US08/816,822
• Time in Patent Office: 530 Days
• Field of Search: 607/4, 607/5, 607/6, 607/7, 607/8, 607/14
• US Class Current: 607/5
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/37258 Alerting the patient
• CPC Class Codes: A61N 1/3925 Monitoring; Protecting
• CPC Class Codes: A61N 1/39622 Pacing therapy
• CPC Class Codes: A61N 1/3987 characterised by the timing or triggering of the shock

Abstract

An implantable anti-arrhythmia device such as a defibrillator or anti-tachycardia pacemaker with an associated patient activator. In response to the patient activation signal, the implanted device notifies the activator whether an atrial rhythm requiring treatment is present and whether a therapy is available for delivery in response to the patient'"'"'s request. After the patient is notified that a therapy is pending, the implanted device charges its output capacitors and thereafter determines whether opportunities for prompt synchronization are present with a desired frequency, over a preceding series of depolarizations. If both conditions are met, the likelihood that a defibrillation or cardioversion pulse can be delivered quickly following a patient initiated retrigger signal is high, and the device notifies the patient'"'"'s activator that it will await receipt of a patient retrigger signal, as a prerequisite for a delivery of the cardioversion or defibrillation pulse. The patient retrigger signal may take the form of a second downlink from the activator to the implanted device, or may take the form of a defined patient action, detected by the implanted device. For example, the implanted device may be provided with an impedance sensor of the sort typically employed in rate responsive implantable pacemakers to measure respiration rate and minute volume. This sensor may be used to detect the action of the patient holding his or her breath, in preparation to receiving the shock. In this embodiment, the patient'"'"'s own action of bracing to receive the shock may be used as the mechanism for triggering delivery of the shock. An alternative patient trigger might be accomplished by providing the implanted device with a piezoelectric crystal, located on an interior surface of the pacemaker housing, of the sort typically employed to sense physical activity in the rate responsive cardiac pacemakers. This sensor may be employed in the context of the present invention to detect the patient tapping on an implanted device, as a signal to trigger delivery of therapy.

Claims

1. An implantable anti-arrhythmia device comprising:

an cardioversion or defibrillation pulse generator;

means for receiving a patient'"'"'s request for cardioversion or defibrillation;

means for detecting a retrigger signal from the patient; and

control circuitry responsive to the detecting means for triggering the pulse generator to deliver a cardioversion or defibrillation pulse in response to a detected patient retrigger signal following a received request for cardioversion or defibrillation.

8. A device according to any of claims 1-7 wherein the detecting means comprises a telemetry receiver.

9. A device according to any of claims 1-7 wherein the detecting means comprises means for detecting a physical action of the patient.

10. A device according to claim 9 wherein the detecting means comprises means for detecting respiratory activity of the patient.

11. A device according to claim 9 wherein the detecting means comprises means for detecting the patient tapping the implanted device.

2. An implantable anti-arrhythmia device comprising:

an cardioversion or defibrillation pulse generator;

means for receiving a patient'"'"'s request for cardioversion or defibrillation;

a heart rhythm analyzer responsive to a received request for cardioversion or defibrillation for determining whether the patient'"'"'s heart rhythm indicates a need for cardioversion or defibrillation;

means for detecting a retrigger signal from the patient; and

control circuitry responsive to the detecting means and the heart rhythm analyzer for triggering the pulse generator to deliver a cardioversion or defibrillation pulse in response to a detected patient retrigger signal following determination of a need for cardioversion or defibrillation.

3. An implantable anti-arrhythmia device comprising:

an cardioversion or defibrillation pulse generator;

means for receiving a patient'"'"'s request for cardioversion or defibrillation;

means for detecting a retrigger signal from the patient;

a heart rhythm analyzer responsive to a request for cardioversion or defibrillation, for determining whether the patient'"'"'s heart rhythm permits prompt delivery of a cardioversion or defibrillation pulse;

control circuitry responsive to the heart rhythm analyzer and the detecting means for triggering the pulse generator to deliver a cardioversion or defibrillation pulse in response to a patient retrigger signal when the heart rhythm analyzer determines that the patient'"'"'s heart rhythm permits prompt delivery of a cardioversion or defibrillation pulse.

4. A device according to claim 3 wherein the heart rhythm analyzer comprises means for determining whether a preceding series of heart depolarizations included a defined number of opportunities for synchronized delivery of a cardioversion or defibrillation pulse.

5. A device according to claim 4 wherein the control circuitry comprises means for defining a set of synchronization criteria and means for triggering delivery of a cardioversion or defibrillation pulse only if the synchronization criteria are met and wherein the heart rhythm analyzer comprises means for determining whether over a preceding series of heart depolarizations the synchronization criteria were met a defined number of times.

6. An implantable anti-arrhythmia device comprising:

an cardioversion or defibrillation pulse generator;

means for receiving a patient'"'"'s request for cardioversion or defibrillation;

means for detecting a retrigger signal from the patient;

means for informing the patient that a patient retrigger signal will be used to trigger delivery of a cardioversion or defibrillation pulse;

control circuitry responsive to the detecting means for triggering the pulse generator to deliver a cardioversion or defibrillation pulse in response to a patient retrigger signal.

7. An implantable anti-arrhythmia device comprising:

an cardioversion or defibrillation pulse generator;

means for receiving a patient'"'"'s request for cardioversion or defibrillation;

means for detecting a retrigger signal from the patient;

means for informing the patient that a patient retrigger signal will not be used to trigger delivery of a cardioversion or defibrillation pulse;

control circuitry for triggering the pulse generator to deliver a cardioversion or defibrillation pulse in the absence of a patient retrigger signal, after informing the patient that a retrigger signal will not be employed to trigger delivery of a cardioversion or defibrillation pulse.

12. A method of operating an implantable anti-arrhythmia device, comprising:

implanting a device including cardioversion or defibrillation pulse generator;

receiving a patient'"'"'s request for cardioversion or defibrillation;

detecting a retrigger signal from the patient; and

triggering the pulse generator to deliver a cardioversion or defibrillation pulse in response to a detected patient retrigger signal following a received request for cardioversion or defibrillation.

19. A method according to any of claims 12-18 wherein the device comprises a telemetry receiver and wherein the detecting step comprises detecting a retrigger signal using the telemetry receiver.

20. A method according to any of claims 12-16 wherein the detecting step comprises detecting a physical action of the patient.

21. A method according to claim 20 wherein the detecting step comprises detecting respiratory activity of the patient.

22. A method according to claim 20 wherein the detecting step comprises detecting the patient tapping the implanted device.

13. A method of operation of an implantable anti-arrhythmia device, comprising:

implanting a device including a cardioversion or defibrillation pulse generator;

receiving a patient'"'"'s request for cardioversion or defibrillation;

responsive to a received request for cardioversion or defibrillation, determining whether the patient'"'"'s heart rhythm indicates a need for cardioversion or defibrillation;

detecting a retrigger signal from the patient; and

triggering the pulse generator to deliver a cardioversion or defibrillation pulse in response to a detected patient retrigger signal following determination of a need for cardioversion or defibrillation.

14. A method of operation of an implantable anti-arrhythmia device comprising:

implanting a device comprising a cardioversion or defibrillation pulse generator;

receiving a patient'"'"'s request for cardioversion or defibrillation;

detecting a retrigger signal from the patient;

responsive to a request for cardioversion or defibrillation, determining whether the patient'"'"'s heart rhythm permits prompt delivery of a cardioversion or defibrillation pulse;

triggering the pulse generator to deliver a cardioversion or defibrillation pulse in response to a patient retrigger signal when the heart rhythm analyzer determines that the patient'"'"'s heart rhythm permits prompt delivery of a cardioversion or defibrillation pulse.

15. A method according to claim 14 wherein the step of determining whether the patient'"'"'s heart rhythm permits prompt delivery of a cardoversion or defibrillation pulse comprises determining whether a preceding series of heart depolarizations included a defined number of opportunities for delivery of a cardioversion or defibrillation pulse.

16. A method according to claim 15 wherein the step of determining whether the patient'"'"'s heart rhythm permits prompt delivery of a cardoversion or defibrillation pulse comprises defining a set of synchronization criteria and determining whether over a preceding series of heart depolarizations the synchronization criteria were met a defined number of times.

17. A method of operating an implantable anti-arrhythmia device, comprising:

implanting a device comprising a cardioversion or defibrillation pulse generator;

receiving a patient'"'"'s request for cardioversion or defibrillation;

after detecting the patient'"'"'s request, informing the patient that a patient retrigger signal will be used to trigger delivery of a cardioversion or defibrillation pulse;

after informing the patient, triggering the pulse generator to deliver a cardioversion or defibrillation pulse in response to a detected patient retrigger signal.

18. A method of operating an implantable anti-arrhythmia device, comprising:

implanting a device comprising a cardioversion or defibrillation pulse generator;

receiving a patient'"'"'s request for cardioversion or defibrillation;

informing the patient that a patient retrigger signal will not be used to trigger delivery of a cardioversion or defibrillation pulse;

after informing the patient, triggering the pulse generator to deliver a cardioversion or defibrillation pulse in the absence of a patient retrigger signal.