Pacemaker with sudden rate drop detection based on QT variations
First Claim
1. An implantable pacing system having a pacemaker device and a lead that interconnects a patient'"'"'s heart and said device, said device comprising:
- sensing means for sensing ventricular signals connected from the patient'"'"'s bean;
rate means for determining patient heart rate from sensed signals;
QT means for determining a measure of the QT interval from said sensed signals;
differential means for determining and storing differential changes in said QT measure from beat to beat;
analysis means for determining when said differential changes indicate the onset of SRD; and
intervention means for controlling said pacemaker device to pace said patient with intervening pacing pulses in response to a said indication of onset of SRD.
1 Assignment
0 Petitions
Accused Products
Abstract
The invention provides an implantable medical device system and method for determining when a patient is undergoing a sudden rate drop (SRD) that should be treated by intervention therapy. Two SRD detection algorithms are provided. A first algorithm is a rate-based algorithm that looks for rate drops that meet stored SRD criteria, and a second algorithm is a QT-based algorithm that detects when QT variations meet criteria that are associated with rate changes characteristic of onset of NMS. The system provides for a plurality of different intervention pacing therapies that are selected based on which detection algorithm, or both algorithms, indicate SRD. The priority of choice of algorithms is programmable.
75 Citations
53 Claims
-
1. An implantable pacing system having a pacemaker device and a lead that interconnects a patient'"'"'s heart and said device, said device comprising:
-
sensing means for sensing ventricular signals connected from the patient'"'"'s bean;
rate means for determining patient heart rate from sensed signals;
QT means for determining a measure of the QT interval from said sensed signals;
differential means for determining and storing differential changes in said QT measure from beat to beat;
analysis means for determining when said differential changes indicate the onset of SRD; and
intervention means for controlling said pacemaker device to pace said patient with intervening pacing pulses in response to a said indication of onset of SRD. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. An implantable medical system having a pacing device and a lead system interconnecting said device with the heart of a patient, said device comprising:
-
signal means for sensing cardiac signals from said patient;
first rate drop detection means for determining a first parameter from said signals and detecting sudden rate drop as a function of variations of said first parameter;
second rate drop detection means for determining a second parameter from said signals and detecting sudden rate drop as a function of variations of said second parameter; and
intervention pacing means for pacing said heart with intervention pacing when at least one of said first and second detection means detects sudden rate drop, wherein said intervention means comprises a plurality of intervention algorithms for controlling intervention pacing, and selection means for selecting one of said algorithms depending on which of said first and second detection means detects sudden rate drop. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21)
-
-
22. A method of determining the onset of SRD in a patient having an implanted cardiac device, comprising:
-
storing in said device predetermined criteria relating to normal beat-to-beat behavior of QT;
obtaining measures of QT for patient heartbeats;
comparing said measures with said criteria;
determining the onset of SRD as a function of said comparing; and
calculating a value of OTc for each said patient heartbeat, and determining variations in said OTc values. - View Dependent Claims (23, 24, 25, 26, 27, 28)
-
-
29. A method of detecting and treating sudden rate drop in a patient, utilizing an implanted medical device system, comprising:
-
storing in said system a plurality of sudden rate drop detection algorithms, and enabling and operating at least one of said algorithms;
storing in said system a plurality of intervention pacing routines;
providing an indication when sudden rate drop is detected by a said detection algorithm;
selecting one of said intervention pacing routines in response to a said indication; and
treating said patient with intervention pacing controlled by said selected routine. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50)
-
-
51. An implantable medical system having a pacing device and a lead system interconnecting said device with the heart of a patient, said device comprising:
-
signal means for sensing cardiac signals from said patient;
first rate drop detection means fix determining a first parameter from said signals and detecting sudden rate drop as a function of variations of said first parameter;
second rate drop detection means for determining a second parameter from said signals and detecting sudden rate drop as a function of variations of said second parameter, and intervention pacing means for pacing said heart with intervention pacing when a prioritized variable detects sudden rate drop. - View Dependent Claims (52, 53)
-
Specification