Apparatus and methods of optimizing atrioventricular pacing delay intervals

Abstract

Provided herewith are methods and apparatus for optimizing an atrioventricular (AV) pacing delay interval based upon ECG-based optimization is calculated as a linear function of P-wave duration, sensed PR (intrinsic) interval, sensed or paced QRS duration and heart rate. Since the relationship among these parameters is linear, once the coefficients are solved (which can be any value, including null) with reference to a known optimized AV interval (AVopt) such as from an echocardiographic study, an AVopt value can be dynamically adjusted in an ambulatory subject. The various combinations of values can be loaded into a look up table or calculated automatically. And, since some of the parameters do not typically change much over time they can be determined acutely and fed into the equation while the other values can be measured frequently. The parameter values can be measured by an implantable medical device such as a dual- or triple-chamber pacemaker.

Description

RELATED APPLICATION[0001]This application is a continuation of U.S. patent application Ser. No. 13 / 084,244, filed Apr. 11, 2011 entitled “APPARATUS AND METHODS OF OPTIMIZING ATRIOVENTRICULAR PACING DELAY INTERVALS”, which is a divisional of U.S. patent application Ser. No. 12 / 047,876, filed Mar. 13, 2008 entitled “APPARATUS AND METHODS OF OPTIMIZING ATRIOVENTRICULAR PACING DELAY INTERVALS”, now U.S. Pat. No. 7,941,218, herein incorporated by reference in its entirety.FIELD[0002]This invention relates to cardiac pacing systems, and more particularly to apparatus and methods for improving cardiac function by optimizing atrioventricular (AV) timing intervals for a cardiac pacing system, such as a dual-chamber or a triple-chamber cardiac resynchronization therapy (CRT) delivery system.BACKGROUND[0003]Cardiac resynchronization therapy (CRT) is a promising and accepted device therapy for patients with systolic heart failure classified in New York Heart Association (NYHA) class III and IV....

AI Technical Summary

Benefits of technology

[0007]Embodiments of the invention provide relatively simple apparatus and methods of AV timing optimization based on intracardiac electrograms, subcutaneous, or surface ECG. Such apparatus and methods are highly desirable as a simple and effective means of assuring optimized pacing delivery. Certain embodiments provide complex echocardiographic interval optimization by being based on surface, subcutaneous (so-called leadless arrays providing electrode vectors) ECG and / or intracardiac EGM signals and can be performed acutely and chronically.

Problems solved by technology

Of course, the algorithm is not the exclusive manner of determining PWend and PWd, however, as other methods could be utilized such as by determining changes to the slope of the P-wave signal, threshold crossings, changing polarity of the signal, and the like.

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