Pacesetter, Inc.

Siemens-pacesetter, Inc.

Roy B Medlin

John W Poore

Brian M Mann

Jeffery D Snell

Harold C Schloss

Joseph J Florio

An implantable dual-chamber pacemaker programmed to operate primarily in an atrial tracking mode is provided, where the pacemaker maintains a consistent atrial rate of entry into, and exit from, a 2:1 block response mode by setting rate-responsive AV delay values in accordance with a continually monitored intrinsic atrial rate incorporating atrial events occurring during atrial refractory periods. The atrial rate of entry into, and exit from the 2:1 block response mode is determined by the length of a total atrial refractory period, which is the sum of the rate-responsive AV delay and a programmable refractory period.

Method and apparatus for providing enhanced 2:1 block response with

An implantable pacemaker continuously records pacing events and their respective rates of occurrence in sequence, as they occur, into an Event Record stored in a circular buffer. The circular buffer always contains the most recent events and rates collected. The recording of the pacing events selectively occurs at every event, or at sampling rates of one event per fixed sample interval. A programming device, coupled to the implantable pacemaker through a telemetry link, selectively retrieves the recorded pacing events and rates from the Event Record and reports subsets thereof in condensed or summarized form using numerical and/or graphical formats. The pacing event data collected in the Event Record is three-dimensional in that each pacing event includes a pacemaker event, an associated pacemaker or heart rate, and a real time interval. The programming device also calculates and reports statistical information from the data collected in the Event Record. The Event Record provides a base recording that establishes the behavior of the pacemaker in a particular patient under ascertainable conditions.

Method and apparatus for reporting and displaying a sequential series of

Methods for displaying a sequential series of pacing events

Method and system for recording and displaying a sequential series of

A rate-response pacemaker includes a plurality of sensors that each sense a physiologic-related parameter suggestive of the physiological needs of a patient, and hence indicative of the pacing rate at which the rate-responsive pacemaker should provide pacing pulses on demand. The pacemaker includes appropriate selection circuitry for selecting which of the sensor parameters or weighted combinations thereof, should be used as the sensor indicated rate (SIR) signal to control the pacing rate of the pacemaker at any given time. In a preferred embodiment, a maximum sensor rate signal (MR.sub.i) is computed for each sensor, and a maximum sensor rate (MSR) signal is defined for the pacemaker, and the SIR signal is selected as the lesser of: (i) the MSR signal; (ii) the largest of the sensed sensor parameters; or (iii) the respective MR.sub.i signals.

Multi-sensor rate-responsive pacemaker and method of operating same

A programmable offset is added to an automatically generated baseline reference value to provide a Threshold value used by the rate-responsive sensor processing circuits of an implantable rate-responsive pacemaker to determine the significance of a sensor input signal. The rate-responsive pacemaker provides stimulation pulses on demand at a pacing rate determined by a sensed physiological parameter. The physiological parameter is sensed by a physiological sensor included within, or coupled to, the rate-responsive pacemaker. The physiological sensor generates a sensor input signal having a magnitude that varies as a function of the sensed physiological parameter. The invention provides a way for the rate-responsive pacemaker, when operating in an autothreshold mode, to automatically determine when the magnitude of the sensor input signal is sufficiently large to justify an increase in the pacing rate. A long-term running average of the sensor input signal is continuously maintained, and is used as a baseline threshold value. A programmable offset is added to the baseline reference value. Any sensor input signal that exceeds the baseline reference value plus the programmable offset is considered to be sufficiently large to effect an increase in the pacing rate.

Rate-responsive pacemaker having automatic sensor threshold with

A method and system for monitoring the behavior of an implanted pacemaker counts (records) the number of times that a given internal event or state change of the pacemaker occurs, and also determines the rate at which each event or state change thus counted occurs. The event counts and their associated rate are stored (recorded) in appropriate memory circuits housed within the pacemaker device. At an appropriate time, the stored event count and rate data are downloaded to an external programming device. The external programming device processes the event count and rate data, and displays a distribution of the event count data as a function of its rate of occurrence, as well as other statistical information derived therefrom. The displayed information, and its associated statistical information, allows a baseline recording to be made that establishes the implanted pacemaker's behavior for a given patient under known conditions. Such baseline recording of event counts in combination with the associated rate of occurrence of such event counts provides significant insight into the past behavior of the pacemaker as implanted in a particular patient. The past behavior of the pacemaker, in turn, may then be used to predict with a high degree of accuracy the future behavior of the pacemaker.

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West Hills, CA, United States of America

Roy B Medlin