Apparatus and methods for automatic adjustment of av interval to ensure delivery of cardiac resynchronization therapy

Abstract

Methods and apparatus of left ventricular pacing including automated adjustment of a atrio-ventricular (AV) pacing delay interval and intrinsic AV nodal conduction testing. Thus, in the event that the AV conduction test reveals a physiologically acceptable intrinsic PR interval then storing the physiologically acceptable PR interval in a memory structure (e.g., a median P-R from one or more cardiac cycles) and delivering fusion pacing using a decremented value of the intrinsic PR interval.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. patent application Ser. No. 12 / 505,925, filed Jul. 20, 2009 entitled “APPARATUS AND METHODS FOR AUTOMATIC ADJUSTMENT OF AV INTERVAL TO ENSURE DELIVERY OF CARDIAC RESYNCHRONIZATION THERAPY” (P0025111.01), and Ser. No. 11 / 671,345 filed on Feb. 5, 2007, entitled “APPARATUS AND METHODS FOR AUTOMATIC ADJUSTMENT OF AV INTERVAL TO ENSURE DELIVERY OF CARDIAC RESYNCHRONIZATION THERAPY” (P0025111.00) This application claims the benefit of provisional U.S. patent application Ser. No. 60 / 765,034 filed 3 Feb. 2006. The disclosure(s) of the above application(s) is (are) incorporated herein by reference. This application is also related to U.S. application Ser. No. ______, filed ______ and entitled “APPARATUS AND METHODS FOR AUTOMATIC ADJUSTMENT OF AV INTERVAL TO ENSURE DELIVERY OF CARDIAC RESYNCHRONIZATION THERAPY” (P0025111.USU3) and also relates to a non-provisional U.S. Pat. No. 6,871,096 to Hill, entitled,...

AI Technical Summary

Benefits of technology

The invention provides a simpler way to deliver CRT therapy to patients with heart failure. This method optimizes the timing of pacing intervals without requiring individualized optimization. The therapy involves delivering electrical signals to the heart to induce consistent activation of the ventricles. The method can be used with a variety of sensing and pacing locations, and can be tailored to different heart conditions. This approach could help improve the response of CRT therapy in patients with heart failure.

Problems solved by technology

However, due to a number of factors (e.g., the amount of time required for appropriate signal processing, confounding conduction delays or conduction blockage of a patient, diverse electrode placement locations, and the like) for a variety of patients the system described may not always effectively delivery CRT.

The challenge in such a system is determining the appropriate moment to delivery the single ventricular pacing stimulus, especially since such timing can be expected to vary with the timing dependent on the physiologic status of the patient (e.g., exercise, medications etc).

Heretofore, such pre-excitation was not possible because in the prior art, the fusion-pacing stimulus was triggered by a sensed event in the opposite chamber.

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