Abstract: A method and system facilitates the access by a patient of implanted medical device related data for patient participation in their own clinical care and therapy. In an example embodiment, the method includes establishing a communications link between an implanted medical device and a data processor via an implanted medical device interface. Access to a secured database is obtained via the implanted device data processor using a set of patient identification data. A query is then submitted via the data processor to the secured database in response to input patient diagnostic data. Data received from the secured database is then displayed for use in a patient evaluation.

Abstract: The invention relates to the use of atrial pacing therapies to treat atrial tachycardia (AT). When an AT episode is detected, an implantable medical device applies an ATP therapy. If the AT episode persists, the ATP therapy may be automatically reapplied at a later time during the course of the same AT episode. In particular, previously used ATP therapies are reapplied when episodic conditions, such as cycle length or cycle regularity, change. Although a particular ATP therapy initially may be unsuccessful in terminating the AT, it may prove successful when the cycle length or regularity of the atrial rhythm changes. As the rhythm slows down, the AT may be more responsive to ATP therapies that were previously unsuccessful. As a result, potentially efficacious ATP therapies can be reapplied to terminate AT episodes, and reduce the number of episodes that require more aggressive termination by painful, atrial shocks.

Abstract: Notifying a patient or another person of an arrhythmia episode facilitates management of atrial fibrillation (AF) and other arrhythmias, including atrial flutter, atrial tachycardia, and supra ventricular tachycardia, thus enabling the patient to take corrective action even in the absence of symptoms or latent cardiac problems. For example, the patient may be prompted to take a medication, to initiate electrical therapy in the form of pacing or defibrillation, or to seek medical attention. Notification may be issued either by an implantable medical device or by an external device in communication with the implantable medical device. Various types of notifications may be issued under a variety of conditions, some of which may be associated with the duration of an episode.

Abstract: A medical device selects the most appropriate among various calculated escape intervals for use in the next cardiac cycle. This is particularly implemented in cardiac event in which a pacemaker is used to prevent multiple tachyarrhythmias. The prevention pacing modes may be simultaneously active, with the escape interval for each mode calculated and updated on a beat-by-beat basis. The medical device selects tachyarrhythmia prevention pacing modality to control the escape interval of the current cardiac cycle in order that a more appropriate method for calculating the escape interval based on the present condition of the patient, may be selected.

Abstract: A method and system facilitates the access by a patient of implanted medical device related data for patient participation in their own clinical care and therapy. In an example embodiment, the method includes establishing a communications link between an implanted medical device and a data processor via an implanted medical device interface. Access to a secured database is obtained via the implanted device data processor using a set of patient identification data. A query is then submitted via the data processor to the secured database in response to input patient diagnostic data. Data received from the secured database is then displayed for use in a patient evaluation.

Abstract: A method and apparatus for determining the occurrence of a mis-location of an atrial electrode in a cardiac stimulation device having an atrial pulse generator coupled with the atrial electrode and a ventricular sense amplifier coupled to a ventricular electrode. The device paces the atrium in a first pacing mode employing atrial pacing pulses at a first energy level and in a test mode employs higher energy atrial pacing pulses. In the test mode the device measures PR intervals between atrial pacing pulses following sensed ventricular depolarizations and determines that the atrial electrode is mis-located responsive to occurrence of a threshold number of short PR intervals or that the atrial electrode is appropriately located responsive to occurrence of a threshold number of long PR intervals. Operation of the device in the test mode may be pre-conditioned on an absence of atrial tachyarrhythmia.

Abstract: An AV search method and apparatus is taught with some variation. It allows a pacemaker to find the appropriate AV interval so as to avoid pacing in the ventricle when it is not necessary, even if there is intermittent AV conduction in the patient. Also, there is an adaptive PVARP method and apparatus that allows the PVARP and AV interval to be adjusted together automatically.

Abstract: There is provided a system and method applicable for use with a dual chamber pacemaker for determining whether long atrial intervals are due to atrial undersensing or to sick sinus syndrome. The determination of undersensing is based upon an algorithm which statistically analyzes a long atrial interval in terms of the patient's prior atrial rate history, and compares a calculated statistical probability measure with an empirically determined undersense threshold factor. The pacemaker can respond to a determination of undersensing by correcting already collected diagnostic data, adjusting one or more pacemaker operating parameters, adjusting synchronous tracking and/or providing an annotated marker channel for indicating undersense events.

Abstract: A method and apparatus for the simultaneous administration of multiple pacing therapies in which two or more pacing features which operate to cause the dynamic adjustment of a common operational parameter of a pacing system are activatable at the same time. In one embodiment, a prioritization among multiple pacing features is established, such that when two (or more) features which operate to cause adjustment of a common operational parameter, a lower-priority feature will not override an adjustment made by any higher-priority feature.

Abstract: An atrial and ventricular pacemaker including an atrial pulse generator having the capability of delivering high rate atrial pacing pulses for electrophysiologic study and having the capability of delivering ventricular pacing pulses as a backup, during delivery of high rate atrial pacing pulses. Delivery of backup ventricular pacing pulses may be preconditioned upon the occurrence of a desired number, proportion or pattern of occurrences of paced ventricular beats preceding delivery of high rate atrial pacing pulses. Timing of ventricular backup pulses is synchronized to delivered atrial pacing pulses which occur closely timed to expiration of a defined ventricular escape interval for backup pacing. The defined escape interval for ventricular backup pacing may be set as a function of the average interval separating ventricular events preceding initiation of high rate atrial pacing.

Abstract: An AV search method and apparatus is taught with some variation described. It allows a pacemaker to find the appropriate AV interval so as to avoid pacing in the ventricle when it is not necessary, even if there is intermittent AV conduction in the patient. Also, an adaptive PVARP method and apparatus is disclosed that allows the PVARP and AV interval to be adjusted together automatically.

Abstract: Some false tachy detection prevention algorithms miss blocked 2:1 sensing and therefore miss some true tachy situations. Here an algorithm that uses sensed far field R waves to determine whether to search for blocked 2:1 sensing is implemented and a search algorithm is also described.

Abstract: A pacemaker control method and apparatus for determining the presence of atrial tachyarrhythmias uses a true interval value and compares it to a predetermined tachy value. The true interval value is updated based on the presence of far field R waves in PVARP that meet certain sequencing criteria. The criteria selected allows the control method and apparatus to reduce or eliminate event sequences that will generate false positive tachy detection and subsequent mode switching, while still allowing for the detection of tachy events in PVARP.

Abstract: A dual chamber pacemaker is provided having capability for adjusting the AV escape interval so as to optimize the timing of delivered ventricular pace pulses for therapy of patients with cardiomyopathy. The pacemaker system continually monitors to determine when a delivered pace pulse results in a fusion beat, and periodically adjusts the AV escape interval in accordance with the percentage or rate of incidence of such fusion beats. In one specific embodiment, the pacing system determines the percentage of delivered ventricular pace pulses which are followed by fusion beats over a predetermined number of intervals, and decrements AV escape interval when such percentage is not below a predetermined minimum. The pacing system also periodically increments AV escape interval when the rate of fusion beats is acceptable, thereby providing a closed loop system for maintaining the AV interval at an optimally long value consistent with maximizing full capture by delivered ventricular pace pulses.

Abstract: A method and apparatus for variable rate cardiac stimulation, wherein sudden drops in the rate of delivery of stimulation pulses are avoided by means of rate smoothing and peak rate support functions. In one embodiment, circuitry in a cardiac pulse generator detects atrial events and maintains an updated value of the A-A time intervals between certain atrial events. If a preset ratio or total of these A-A intervals are found to have been shorter than the updated value by at a least a predetermined amount of time, a rate smoothing function is activated wherein the rate of delivery of stimulating pulses is prevented from changing, from cycle to cycle, by more than a predetermined maximum amount. A peak rate support function preferably employs the same updated value in the computation of "escape" intervals. Following the latest A-A interval, if that A-A interval is less than the updated value, then the updated value is used as the new escape interval.

Abstract: A dual chamber pacemaker is provided having capability for adjusting the AV escape interval so as to optimize the timing of delivered ventricular pace pulses for therapy of patients with cardiomyopathy. The pacemaker system continually monitors to determine when a delivered pace pulse results in a fusion beat, and periodically adjusts the AV escape interval in accordance with the percentage or rate of incidence of such fusion beats. In one specific embodiment, the pacing system determines the percentage of delivered ventricular pace pulses which are followed by fusion beats over a predetermined number of intervals, and decrements AV escape interval when such percentage is not below a predetermined minimum. The pacing system also periodically increments AV escape interval when the rate of fusion beats is acceptable, thereby providing a closed loop system for maintaining the AV interval at an optimally long value consistent with maximizing full capture by delivered ventricular pace pulses.

Abstract: New pacing algorithm defines faster than indicated pacing rate during detection of PAC's/PVC's and reduces rate after awhile to a safety rate unless natural depolarizations are detected.

Abstract: A method and apparatus for cardiac pacing, which provides for delivery of pacing pulses at an increased rate in response to a detected rapid drop in heart rate. A rapid drop may be detected in response to a drop of greater than a defined amount from the highest detected heart rate, over a preceding time period. Alternatively, an unbroken sequence of pacing pulses delivered at a base pacing rate may trigger pacing at an increased pacing rate.

Abstract: A rate-responsive cardiac pacemaker implements a novel pacing mode, identified as ADIR/VVIR, which is especially effective for patients with Sick Sinus Syndrome and only intermittent atrioventricular block. Within the same pacemaker circuitry, an AAIR pacemaker and a VVI pacemaker (with an escape rate below that of the AAIR pacemaker) are provided with atrial blanking following both atrial and ventricular events. Ventricular blanking after atrial pacing is minimized for better detection of R-waves following an atrial paced event.

Abstract: A dual chamber pacemaker is provided having capability for adjusting the AV escape interval so as to optimize the timing of delivered ventricular pace pulses for therapy of patients with cardiomyopathy. The pacemaker system continually monitors to determine when a delivered pace pulse results in a fusion beat, and periodically adjusts the AV escape interval in accordance with the percentage or rate of incidence of such fusion beats. In one specific embodiment, the pacing system determines the percentage of delivered ventricular pace pulses which are followed by fusion beats over a predetermined number of intervals, and decrements AV escape interval when such percentage is not below a predetermined minimum. The pacing system also periodically increments AV escape interval when the rate of fusion beats is acceptable, thereby providing a closed loop system for maintaining the AV interval at an optimally long value consistent with maximizing full capture by delivered ventricular pace pulses.