Abstract: An implantable medical device provides atrial arrhythmia prevention pacing when an interatrial conduction disturbance is detected. The implantable medical device includes a signal processor that detects the interatrial conduction disturbance and a pulse generator circuit coupled to the detector that delivers the atrial arrhythmia prevention pacing pulses to the heart when the processor detects the interatrial conduction disturbance. The interatrial conduction disturbance may be a P-wave duration, a difference between odd and even P-waves, or a predetermined P-wave spectral energy distribution.

Abstract: A system and corresponding method are disclosed for discriminating between far field R-waves and actual atrial events that are sensed on an atrial sense channel. In one embodiment, such information is used to prevent mode switching. In another embodiment, the information is used to extend an atrial blanking period so that the far field R-waves are no longer sensed on an atrial channel.

Abstract: Systems and methods are provided for collecting enhanced diagnostic information specifically pertaining to overdrive pacing within an implantable cardiac stimulation device and for processing and displaying the enhanced diagnostic information using an external programmer. The enhanced diagnostic information includes one or more of overdrive pacing efficacy, overdrive pacing percentage, overdrive pacing/heart rate histogram data, longest recovery duration, atrial event data, minimum/maximum/average of the overdrive pacing rate, number of paced beats at maximum rate, duration of recovery time from maximum rate, intrinsic rate breakthrough histogram data, and number of rate increases. By tracking and displaying the enhanced diagnostic information, a physician can thereby more effectively and reliably program overdrive pacing control parameters to achieve optimal overdrive pacing performance.

Abstract: A system and method for performing bipolar sensing and pacing in a heart using a unipolar atrial electrode. The invention provides a lead system comprising an atrial electrode placed in the atrium of the heart and a defibrillation electrode placed in the heart. The defibrillation electrode may be placed in the ventricle, the superior vena cava, or the coronary sinus. Bipolar pacing and sensing in the atrium is achieved without the introduction of additional conductors into the atrium.

Abstract: An improved system and method for performing automatic capture/threshold detection in an implantable cardiac stimulation device or any device capable of stimulating some organ or tissue in the body. In existing systems a threshold stimulation energy level is periodically determined and a working stimulation energy level is then set by increasing the threshold stimulation energy level by a fixed or preprogrammed safety margin, e.g., a fixed voltage level or a percentage safety margin. However, in certain circumstances this safety margin may not be sufficient, resulting in either frequent threshold level determinations or losses-of-capture. To avoid these situations which may be wasteful of battery energy or dangerous for the patient, embodiments of the present invention periodically increase and/or decrease the safety margin according to the performance of the stimulation device, i.e., based upon the frequency of capture.

Abstract: An implantable medical device provides atrial arrhythmia prevention pacing when an interatrial conduction disturbance is detected. The implantable medical device includes a signal processor that detects the interatrial conduction disturbance and a pulse generator circuit coupled to the detector that delivers the atrial arrhythmia prevention pacing pulses to the heart when the processor detects the interatrial conduction disturbance. The interatrial conduction disturbance may be a P-wave duration, a difference between odd and even P-waves, or a predetermined P-wave spectral energy distribution.

Abstract: An implantable cardiac pacemaker is provided for delivering pacing pulses to a patient, where the pacing pulses are defined by at least two parameters. The pacemaker allows for transitioning of the two parameters from first values to second values in response to the patient's circadian rhythms, such as in response to the beginning and ending of a sleep cycle. Also provided is an implantable pacemaker for delivering pacing pulses to a patient where the pacing pulses are defined by at least one parameter. The pacemaker allows for selective transitioning of the parameter from a first value to a second value in response to the patient's circadian rhythms.

Abstract: A periodic electrical lead integrity testing system is provided which periodically tests electrical leads used with an implantable cardiac stimulating device. The system is especially advantageous in multi-functional implantable cardiac stimulating devices. Lead integrity is evaluated by periodically comparing the impedance of the electrical leads to a reference impedance. A pass/fail algorithm is used to determine if electrical lead integrity has been compromised. The system improves the efficacy and safety of implantable cardiac stimulating devices by detecting electrical failures independent of the delivery of therapeutic shocks. The required circuitry adds only minimal complexity and cost to the implantable cardiac stimulating device.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An analyzer-programmer system (30) for use with an implantable medical device, such as a cardiac pacemaker (20). The system facilitates non-invasive communications with the implantable device and makes analysis of the operation of the implantable device easier to understand and perform. The system includes conventional processor means (42) for processing a sequence of stored instructions stored in programmable read-only memory, or ROM (40). The ROM, although designed to be accessed through predefined page of information, and blocks within such pages, is configured to allow in-page addressing within any of a plurality of pages in a linear fashion. Programmed intervals to be sent to the implantable device are displayed by the system in tabular form or as scaled time-lines or bars (FIG. 9A), with each separate interval beginning and ending in proper timed sequence, thereby providing a prediction of the expected performance. Such programmed intervals can overlay or sidelay measured performance (FIG.