Pacesetter, Inc.

Telectronics Pacing Systems, Inc.

Other

Dow Corning Corporation

Packsetter, Inc.

Richard M Lu

Bruce M Steinhaus

Peter A Crosby

Albert K Dawson

Saul E Greenhut

Tibor A Nappholz

Joseph J Florio

Lisa P Weinberg

Harold C Schloss

Kenneth A Collins

Gregory C Bevan

David W Adinolfi

Janice Barstad

Peter M Nickolls

Corey L Brown

Janice Nolan

Lucy M Cheatle

Roy M McCulloch

Brian Cleland

An implantable, multi-chamber cardiac stimulation device and method automatically adjust inter-chamber stimulation delays whenever stimulation rate is changed according to a patient's metabolic need. Inter-chamber stimulation delays include inter-atrial delays, inter-ventricular delays, and atrio-ventricular delays. Inter-chamber stimulation delays are defined according to whether the event which triggers the start of the delay is an intrinsic sensed event or the delivery of a stimulation pulse. Adjustment to inter-chamber stimulation delays is made as a function of the stimulation rate changes. By providing automatically adjustable inter-chamber stimulation delays optimal synchronization of heart chamber contractions may be maintained at all stimulation rates.

Multi-site cardiac stimulation device for controlling inter-chamber stimulation delay

An implantable cardiac device returns activations of corresponding right and left chambers of a heart to inter-chamber synchrony. A sensing circuit senses intracardiac signals representing right and left chamber ventricular electrical activity. A detector determines if a predetermined characteristic of the electrogram signals indicates dissociation of the corresponding right and left chambers. If dissociation is indicated, a pulse generator stimulates at least one of the corresponding chambers to restore inter-chamber synchrony.

Implantable cardiac device for restoring inter-chamber synchrony and method

An implantable cardiac stimulation device provides a stimulation therapy or an atrial ablation recommendation responsive to detection of atrial flutter of a heart. The device includes a sensing circuit that senses electrical activity of a heart and generates electrical signals representing electrical activity of the heart, an arrhythmia detector that detects atrial flutter of the heart, and a data processor that measures cardiac data responsive to the electrical signals. A therapy control responsive to the detection of atrial flutter recommends atrial ablation of the heart when the cardiac data satisfies a predetermined criteria and atrial flutter suppression when the cardiac data fails to satisfy the predetermined criteria. The device may further include a pulse generator that provides stimulation therapy to at least one atrium to terminate the atrial flutter.

Implantable cardiac stimulation device which recommends ablation therapy and method

Various embodiments can permit electrode configurations that are used in implantable devices to be automatically changed. In some embodiments, configurations that are used to ascertain capture (ventricular and/or atrial) can be automatically changed by a stimulation device and then automatically configured for use. Various parameters associated with the electrical configurations can be automatically calibrated so that a stimulation device's automatic capture feature can continue to function notwithstanding the fact that an electrode configuration change has taken place.

Methods and systems for automatically switching electrode configurations

Techniques are provided for programming a rate-responsive pacemaker or other implantable cardiac stimulation device capable of rate-responsive pacing. In one embodiment, an external programmer is configured to allow a physician to program the pacemaker with a smooth curvilinear rate-responsive pacing function having whatever shape the physician deems optimal for the patient, rather than being limited to generating a linear or bi-linear rate-responsive pacing functions as with many conventional techniques. The rate-responsive pacing function may specify, for example, pacing rates as a function of orthostatic sensor values, activity sensor values, minute ventilation sensor values, vasovagal syncope sensor values or paced depolarization integral sensor values. If several sensors are provided in the pacemaker, smooth rate-responsive pacing functions may be separately generated for use with each sensor.

Method and apparatus for programming a rate responsive implantable cardiac stimulation device using user specified rate response functions

An implantable cardiac stimulation device controls dynamic atrial overdrive pacing based, in part, on sensor indicated rate. In one example, the stimulation device adjusts an overdrive pacing rate based on the sensor indicated rate by periodically decreasing the overdrive pacing rate by a programmed rate decrement whenever a difference between the current overdrive pacing rate and the sensor indicated rate falls outside predetermined acceptable range while the sensor indicated rate is decreasing. The overdrive pacing rate is decreased in this manner until a) the overdrive pacing rate falls below the base rate, rest rate or the sensor indicated rate or until b) an event triggers an increase in the overdrive pacing rate, such as the appearance of intrinsic breakthrough heart beats. The overdrive pacing rate is not decreased if the sensor indicated rate is increasing or stable. With this process, the overdrive pacing rate is controlled to typically remain slightly above the intrinsic rate without being constrained by a preprogrammed number of pacing cycles. Hence, the overdrive pacing rate can be made to closely track the intrinsic rate regardless of whether the intrinsic rate is changing rapidly or is fairly stable.

Dynamic adjustment of overdrive pacing rate based on sensor indicated rate

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.

Detecting and displaying diagnostic information pertaining to dynamic atrial overdrive pacing

An implantable cardiac stimulation device and associated method set an atrial capture detection window by verifying that inter-atrial conduction is intact, and then measuring the inter-atrial conduction time. The measured inter-atrial conduction time may then be used for setting the atrial capture detection window. Capture verification of a stimulated atrial site is then implemented by detecting a conducted depolarization at another atrial site or in the opposite atrial chamber. A signal received during an atrial capture detection window is compared to a depolarization signal threshold or to a depolarization signal template in order to verify detection of a conducted depolarization signal as evidence of capture at the stimulated site. By sensing depolarization signal away from the stimulated site, the negative effects of lead polarization normally encountered when detecting an evoked response are avoided.

Implantable stimulation device and method for performing inter-chamber conduction search and conduction time measurement

Methods and systems for switching electrode configurations for measuring the transthoracic impedance of patient are described. Various embodiments provide stimulation devices and methods that can automatically adapt to different minute ventilation electrode configurations. This, in turn, permits minute ventilation functionality to continue, e.g. rate-responsive pacing, in spite of the fact that an electrode configuration has changed. Accordingly, minute ventilation functionality can automatically continue in a adaptive manner when a previously-available electrode configuration is no longer available for minute ventilation functionality.

Methods and systems for automatically determining minute ventilation

An implantable cardiac stimulation device and associated method to verify capture of a stimulated atrial site by detecting a conducted depolarization at another atrial site or in the opposite atrial chamber. A signal received during an atrial capture detection window is compared to a depolarization signal threshold or to a depolarization signal template in order to verify detection of a conducted depolarization signal as evidence of capture at the stimulated site. By sensing depolarization signal away from the stimulated site, the negative effects of lead polarization normally encountered when detecting an evoked response are avoided.

Implantable stimulation device and method for detecting capture of a heart chamber using cross-chamber conducted depolarization

An implantable cardiac stimulation device and method perform reliable, automatic capture verification during bipolar stimulation by eliminating capture verification during a cardiac cycle in which anodal stimulation is detected. Anodal stimulation is detected by the absence of a delay between the bipolar stimulation pulse and an evoked response sensed at the electrode functioning as the anode during stimulation. Automatic capture verification during bipolar stimulation is recommended only if anodal stimulation is not detected at a working stimulation output. During automatic capture verification, if anodal stimulation is detected, a capture threshold test is performed. A change in anodal stimulation threshold indicates a change in capture threshold. Thus, periodic anodal stimulation threshold tests are also performed to predict when a change in capture threshold has occurred. The device avoids adverse effects of anodal stimulation on evoked response detection and provides a method for predicting changes in capture threshold.

Cardiac stimulation system and method for performing automatic capture verification during bipolar stimulation

An apparatus and method for performing multi-chamber anti-tachycardia pacing (ATP) in response to a tachycardia that is of particular use in an implantable cardiac stimulation device. The expected benefits of such a multi-chamber ATP include improved hemodynamic performance and the ability to terminate the tachycardia sooner. Embodiments of the present invention use an intrinsic chamber activation sequence and associated interchamber time delays, preferably automatically detected during a period of time when a pathologic tachycardia is not present, to treat a pathologic tachycardia should it occur. Such a device monitors two or more chambers of the patient's heart, i.e., the controlled chambers, and in the event a tachycardia is detected, the device determines the chamber which originated the tachycardia. The device then calculates anti-tachycardia pacing (ATP) cycle lengths, typically as percentages of the detected tachycardia cycle length of the chamber where the tachycardia originated, and begins pacing the controlled chambers according to the intrinsic chamber activation sequence and interchamber delays (initially synchronized relative to a cardiac signal from the chamber which originated the tachycardia) at the ATP cycle lengths for a predefined period or until the tachycardia ends. Optionally, embodiments of the present invention may additionally include a hemodynamic sensor and may adaptively alter the activation sequence and/or interchamber time delays in response to feedback from the hemodynamic sensor.

Method and device for multi-chamber cardiac pacing in response to a tachycardia

An apparatus and method for monitoring the patient's heart for the presence of ischemia and altering the treatment delivered by an implantable cardiac stimulation device to minimize adverse ischemic effects, e.g., angina pectoris. Embodiments of the present invention are particularly beneficial when used with a rate responsive cardiac stimulation device. Typically, a rate responsive cardiac stimulation device increases its pacing rate (up to a maximum sensor rate) in response to increases in the patient's activity level. The rate of this change is referred to in this patent as the aggressiveness of the rate responsiveness. However, in an ischemic state, the aggressiveness of the rate responsiveness may cause the heart to pace at a rate that exacerbates the ischemic effects. Accordingly, embodiments of the present invention alter the pacing regimen in one or more of the following ways. First, the maximum sensor rate is adaptively decremented in response to a detected ischemic state. Second, the aggressiveness of the rate responsiveness is adaptively decreased in response to a detected ischemic state. Third, the atrio-ventricular delay (AV) delay is adaptively extended in response to a detected ischemic state. Conversely, when an ischemic state is no longer detected, the adapted variable is incrementally returned toward its original value. Accordingly, ischemia can be minimized while still maintaining the rate responsive features of the implantable cardiac stimulation device.

Method and device for responding to the detection of ischemia in cardiac tissue

An implantable cardiac stimulation device discriminates between noise and an arrhythmia sensed in a heart. A first sensing circuit generates a first signal representing electrical activity sensed in a first location of the heart and a second sensing circuit generates a second signal representing electrical activity sensed in a second location of the heart. The first and second locations are spaced apart and located in respective different corresponding chambers or the same chambers of the heart. A comparison circuit then compares the first and second signals to provide a comparison factor. A control circuit then determines from the comparison factor if noise is sensed or if an arrhythmia is being sensed.

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Highlands Ranch, CO, United States of America

Richard M Lu