Pacemaker with vasovagal snycope detection

• US 5,540,728 A
• Filed: 09/20/1994
• Issued: 07/30/1996
• Est. Priority Date: 05/20/1994
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated MS 301
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Shelton, Michael B., Riff, Kenneth M.
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): Getzow, Scott M.
• Application Number:
  US08/308,910
• Time in Patent Office: 679 Days
• Field of Search: 607/23, 607/24
• US Class Current: 607/23
• CPC Class Codes: A61N 1/365 controlled by a physiological parameter, e.g. heart potential evoked response A61N1/371
• CPC Class Codes: A61N 1/36514 controlled by a physiological quantity other than heart potential, e.g. blood pressure controlled by two or more physical parameters A61N1/36585

Abstract

A method and apparatus of cardiac pacing, in which pacing at an increased rate is provided in response to a detected rapid drop in detected heart rate, to a stable rate below a defined threshold rate.

Claims

1. A cardiac pacer comprising:

means for detecting depolarizations of a heart;

pulse generating means for delivering cardiac pacing pulses at a first pacing rate;

means for defining a threshold heart rate;

drop detecting means for detecting a rapid drop in spontaneous heart depolarization rate to a stable heart rate below said threshold heart rate; and

means responsive to a said detected rapid drop in spontaneous heart depolarization rate, to said stable rate, for causing said pulse generator means to deliver pacing pulses at a second pacing rate higher than said first pacing rate.

2. A cardiac pacer according to claim 1 wherein drop detecting means comprises means for detecting a stable heart rate in response to a series of heartbeats comprising a predetermined number of heartbeats below said threshold rate.

3. A cardiac pacer according to claim 2 wherein drop detecting means comprises means for detecting a stable heart rate in response to a series of a predetermined number of sequential heartbeats below said threshold rate.

4. A cardiac pacer according to claim 1 or claim 2 or claim 3 wherein said drop detecting means comprises means for detecting a rapid drop in spontaneous heart rate in response to a drop in spontaneous heart rate of greater than a defined drop size, over a limited time period.

5. A cardiac pacer according to claim 4 further comprising means for defining a limited number of number of heart beats and wherein said drop detecting means comprises means for detecting a rapid drop in spontaneous heart rate comprises in response to a drop in spontaneous heart rate of greater than said defined drop size, over a series of said limited number of heart beats.

6. A method of cardiac pacing comprising:

detecting depolarizations of a heart;

delivering cardiac pacing pulses at a first pacing rate;

defining a threshold heart rate;

detecting a rapid drop in spontaneous heart depolarization rate to a stable rate below said threshold heart rate; and

responsive to a said detected rapid drop in spontaneous heart depolarization rate, to said stable rate, delivering pacing pulses at a second pacing rate higher than said first pacing rate.

7. A method according to claim 6 wherein said drop detecting step comprises detecting a stable heart rate in response to a series of heartbeats including a predetermined number of heartbeats below said threshold rate.

8. A method according to claim 7 wherein said drop detecting step comprises detecting a stable heart rate in response to a series of a predetermined number of sequential heartbeats below said threshold rate.

9. A method according to claim 6 or claim 7 or claim 8 wherein said drop detecting step further comprises detecting a rapid drop in spontaneous heart rate in response to a drop in spontaneous heart rate of greater than a defined drop size, over a limited time period.

10. A method according to claim 9 wherein said drop detecting step comprises detecting a rapid drop in spontaneous heart rate in response to a drop in spontaneous heart rate of greater than said defined drop size, over a series of a limited number of heart beats.