Medtronic, Inc.

Ren Zhou

Kathleen A Prieve

Jeffrey M Gillberg

Karen J Kleckner

D Curtis Deno

Vincent E Splett

Kenneth M Anderson

David K Peterson

Ruth N Klepfer

Michael R Hill

Glenn C Zillmer

James D Reinke

H Toby Markowitz

John E Burnes

John Charles Stroebel

John C Rueter

James W Busacker

David E Euler

Robert John Schuelke

Edwin G Duffin

Russell E Anderson

Lawrence J Mulligan

David A Igel

Thomas L Jirak

Kevin L Bright

David W Hoffman

Virginia De La Riva

A method of stimulation therapy and an apparatus for providing the therapy which addresses cardiac dysfunction including heart failure. The therapy employs atrial pacing pulses delivered to a heart after the atrial refractory period and timed so that they will not cause a ventricular contraction. These atrial pacing are timed to achieve beneficial effects on myocardial mechanics (efficacy) while maintaining an extremely low level of risk of arrhythmia induction. These methods may be employed individually or in combinations in an external or implantable ESS therapy delivery device.

Secure and efficacious therapy delivery for a pacing engine

An extra-systolic stimulation (ESS) therapy addresses cardiac dysfunction including heart failure. ESS therapy employs atrial and/or ventricular extra-systoles via pacing-level stimulation to a heart. These extra-systoles must be timed correctly to achieve beneficial effects on myocardial mechanics (efficacy) while maintaining an extremely low level of risk of arrhythmia induction and excellent ICD-like arrhythmia sensing and detection (security). The present invention relates to therapy delivery guidance and options for improved ESS therapy delivery. These methods may be employed individually or in combinations in an external or implantable ESS therapy delivery device.

Secure and efficacious therapy delivery for an extra-systolic stimulation pacing engine

Two mechanisms work together to adjust two variables independently so that the gain of an input amplifier used to find physiologic signals in an implantable medical device can be automatically adjusted to enhance the signal to noise ratio of the electrical input to said amplifier. The first determines whether there has been too long a time between senses found in the body's electrical input to the amplifier and if true, and no other conditions override that consideration, it adjusts the value of a long term average parameter which is used as a referent parameter to adjust the actual parameter that is used as the referent for making either a threshold level adjustment or gain change, depending on the structure of the particular design's circuitry and/or software. One set of adjustments to the gain referent parameter depends on the relative size of the long term average parameter and the gain referent parameter. The mechanisms preferably employ counting registers, the one which adjusts the gain referent having a process to weight input signals such that those of different types get different weights, and the other mechanism only accepting certain of the input signals. Input signals to the two mechanisms can be either physiologically based or from stimulation pulses issued from an implanted device, such as, for example a pacemaker.

Method for automatically adjusting the sensitivity of cardiac sense

A pacemaker provided with a mode switching feature adapted to stabilize ventricular heart rate during atrial fibrillation. In a preferred embodiment of the invention, the device nominally operates in an atrial synchronized pacing mode such as DDD, DDDR, VDD or VDDR. In response to detection of atrial rhythm characteristics consistent with atrial fibrillation, the device switches into a non-atrial synchronized, ventricular rate stabilization pacing mode with the base ventricular pacing rate modulated on a beat by beat basis based upon preceding intrinsic or paced ventricular heartbeat intervals to adjust the pacing interval towards a desired preset rate stabilization target pacing interval which is typically less than the programmed base pacing interval of the device. While the ventricular rate stabilization mode is in effect, the current pacing interval is set equal to the preceding intrinsic or paced interval, with an increment if the preceding interval is less than the desired or target pacing interval, as typically will be the case, or with a decrement if the preceding interval is greater than the desired pacing interval. In a preferred embodiment of the invention, the device paces both the atria and ventricles in a DDI rate stabilization pacing mode with the ventricular pacing interval being modulated.

Method and apparatus for diagnosis and treatment of arrhythmias

An implantable pacemaker employing an arrhythmia prevention pacing modality particularly optimized for inclusion in dual chamber pacemakers and anti-arrhythmia devices which include dual chamber pacemakers. When the pacing mode is in effect, the device alters timing of scheduled atrial and/or ventricular pacing pulses in response to depolarizations sensed during the refractory periods and to ventricular depolarizations sensed outside of the pacemaker's A-V escape intervals. The arrhythmia prevention pacing mode is activated and deactivated in conjunction with the operation of arrhythmia detection features which may also be employed by the device to trigger delivery of anti-arrhythmia therapies.

Apparatus for diagnosis and treatment of arrhythmias

Capture detection and stimulation threshold-measurement methods and apparatus for deriving atrial and ventricular pace pulse (A-pace and V-pace) stimulation energy strength-duration data. In a first atrial and ventricular threshold test regimen for use with patients having intact A-V conduction or first degree AV block, A-pace pulses are delivered at a test escape interval and A-V delay. Atrial loss of capture (ALOC) in response to an A-pace test stimulus is declared by the absence of a detected ventricular depolarization (V-event) in the latter portion of the paced A-V delay interval following the delivery of the A-pace test stimulus. In the ventricular threshold test regimen, a V-pace test stimulus is delivered after a shortened A-V delay. Ventricular loss of capture (VLOC) is declared by the detection of a V-event in the ventricular refractory period of the V-pace test stimulus. In a second algorithm for use in the atrium or ventricle in patients having regular measured sinus rhythm, premature A-pace or V-pace test stimuli are delivered, and the presence of an A-event or V-event at the end of the measured sinus escape interval is declared to be ALOC or VLOC, respectively. A-pace and V-pace test stimuli are repeated to confirm capture declarations at an energy exceeding the LOC test energy. The atrial and ventricular stimulation threshold data derived by varying both pulse amplitude (strength) and width (duration) is stored in memory for telemetry out and analysis and for use in setting the V-pace and A-pace normal pulse width and amplitude used between successive auto-capture tests in order to conserve battery energy.

Atrial and ventricular capture detection and threshold-seeking pacemaker

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New Brighton, MN, United States of America

Ren Zhou