Medtronic, Inc.

Nirav Vijay Sheth

John E Burnes

Rahul Mehra

Michael F Hess

Michael R Ujhelyi

Eduardo N Warman

Nancy Perry Pool

Yong Kyun Cho

Karen J Kleckner

Mark L Brown

Li Ping Wang

D Curtis Deno

Thomas J Mullen

Robert A Betzold

David Arthur Casavant

Kathryn Hilpisch

Kevin Patrick Kuehn

David E Euler

Edward Chinchoy

Kenneth M Riff

Lawrence J Mulligan

David E Ritscher

Glenn C Zillmer

Patrick M Mahoney

Clifton W Owens

Li Wang

David Ritscher

A fluid status monitoring system for use in implantable cardiac stimulation or monitoring devices is provided for monitoring changes in thoracic fluid content. A fluid status monitor includes excitation pulse generating and control circuitry, and voltage and current measurement and control circuitry for performing a series of cardiac-gated, intra-thoracic impedance measurements. The cardiac-gated measurements are filtered or time-averaged to provide a fluid status impedance value, with respiratory noise removed. Based on comparative analysis of the fluid status impedance value, a clinically relevant trend in fluid status may be tentatively diagnosed and a fluid status response provided. Cross-check intra-thoracic impedance measurements performed using the same or a different excitation pathway and a different measurement pathway than the primary intra-thoracic impedance measurement configuration may be used to verify a tentative diagnosis.

Method and apparatus for monitoring tissue fluid content for use in an implantable cardiac device

A method and apparatus for optimizing and assessing the response to extra-systolic stimulation (ESS) are provided. An optimization/monitoring parameter is calculated as a function of potentiation ratio, PR, and recirculation fraction, RF, derived from measurements of myocardial contractile function during and after ESS. PR may be computed as the ratio of the contractile function on post-extra-systolic beats during ESS to baseline contractile function. RF may be computed as the slope of a linear regression performed on a plot of the contractile function for a post-extra-systolic beat versus the contractile function for the previous post-extra-systolic beat after ESS is ceased. The ESI resulting in a maximum optimization/monitoring parameter, preferably computed as the product of PR and RF, is determined as the optimal ESI. The operating ESI may be automatically adjusted, and/or PR and RF data may be stored for monitoring purposes.

Method and apparatus for optimization and assessment of response to extra-systolic stimulation (ESS) therapy

Determining an optimal atrioventricular interval is of interest for proper delivery of cardiac resynchronization therapy. Although device optimization is gradually and more frequently being performed through a referral process with which the patient undergoes an echocardiographic optimization, the decision of whether to optimize or not is still generally reserved for the implanting physician. Recent abstracts have suggested a formulaic approach for setting A-V interval based on intrinsic electrical sensing, that may possess considerable appeal to clinicians versus a patient average nominal A-V setting of 100 ms. The present invention presents a methods of setting nominal device settings based on entering patient cardiac demographics to determine what A-V setting may be appropriate. The data is based on retrospective analysis of the MIRACLE trial to determine what major factors determined baseline A-V settings.

Method and apparatus for determining an efficacious atrioventricular delay interval

The present invention provides a technique for verifying pacing capture of a ventricular chamber, particularly to ensure desired delivery of a ventricular pacing regime (e.g., cardiac resynchronization therapy or 'CRT'). The invention also provides for ventricular capture management by delivering a single ventricular pacing stimulus and checking inter-ventricular conduction during a temporal window to determine if the ventricular pacing stimulus captured the chamber. If a loss-of-capture (LOC) signal results from the capture management testing, then the characteristics of the applied pacing pulses are modified and the conduction test repeated. In the event that the LOC signal persists, a pacing mode-switch to an atrial-based pacing therapy and/or non-bi-ventricular pacing regimen can be implemented.

Automatic LV/RV capture verification and diagnostics

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.

Method and a system for using implanted medical device data for accessing therapies

An apparatus and method for discriminating arrhythmias that includes sensing a heart rate indicative of an arrhythmia associated with a first portion of a heart, determining regularity of the sensed heart rate, determining an event interval variability associated with a second portion of the heart, and classifying the arrhythmia in response to the determined event interval variability.

Method and apparatus for detecting and discriminating arrhythmias

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.

Automated reapplication of atrial pacing therapies

A method for preventing early recurrence of atrial fibrillation by pacing a heart in AAI mode at a rate faster than the intrinsic rate for a selected period of time immediately after delivering therapy to terminate the fibrillation. Ventricular backup pacing in VVI mode may also be provided during the atrial pacing.

Method and arrangement for using atrial pacing to prevent early recurrence of atrial fibrillation

A patient-controlled system for temporarily disabling an electrical cardioverting therapy in order to prepare the patient psychologically and physiologically for the pain associated with electrical cardioversion therapy. In an example embodiment, the system includes a capacitive circuit capable of charging and discharging in order to apply the electrical therapy. The implanted medical device automatically causes the capacitive circuit to charge and discharge at least once within a selected period. The system includes a patient activator device that communicates with the implanted device. A disabling circuit is also included within the implanted medical device that temporarily disables the electrical therapy application in response to the patient activator device. The system further includes an alerting arrangement that alerts the patient activator device in response to the disabling circuit. An override circuit overrides the temporary disabling of the electrical therapy application in response to the patient being in a relaxed mode.

Arrangement and system for enabling patient control of electrical therapies

The invention is directed to pacing techniques designed to avoid competitive atrial pacing. In particular, the techniques dynamically adjust a non-competitive atrial pacing (NCAP) interval based on sensed cardiac conditions. An apparatus capable of delivering pacing stimuli, such as a pacemaker or an implantable cardioverter/defibrillator (ICD), is described that inhibits delivery of an atrial pacing stimulus for an NCAP interval having a duration that is adjusted according to sensed cardiac conditions. The apparatus may adjust the duration of the NCAP interval when sensing, for example, premature ventricular contraction (PVC), pacemaker mediated tachycardia (PMT), or atrial arrhythmia (AA).

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Coon Rapids, MN, United States of America

Nirav Vijay Sheth