Patent ID: 7966066

Claim:
A cardiac resynchronization device, comprising: a therapy module for delivering cardiac resynchronization therapy with a selected atrioventricular delay, wherein the cardiac resynchronization therapy includes delivering ventricular pacing upon expiration of a selected atrioventricular delay AVD s after an atrial sense and upon expiration of a selected atrioventricular delay AVD p after an atrial pace; a sensing module and a timer module capable of sensing and timing a plurality of sensed and paced intrinsic atrioventricular intervals at a plurality of rates, wherein a sensed intrinsic atrioventricular interval is the interval between an atrial sense and a ventricular sense and wherein a paced intrinsic atrioventricular interval is the interval between an atrial pace and a ventricular sense; a controller coupled to the timer module capable of calculating a plurality of AVD s values and AVD p values for use in delivering resynchronization therapy at different atrial rates based on the plurality of atrioventricular intervals; a memory module capable of storing the plurality of atrioventricular delay values; wherein the controller is configured to calculate a plurality of different AVD s values for each of a plurality of a sensed atrial rates by: 1) operating in a ventricular pacing mode with atrial sensing but no atrial pacing, 2) when the currently sensed atrial rate corresponds to one of the plurality of sensed atrial rates, calculating and storing an AVD s value for that sensed atrial rate as a function of the intrinsic atrioventricular interval, 3) storing each calculated AVD s value with an associated specified expiration interval so that the AVD s value expires after the expiration interval lapses, 4) when the currently sensed atrial rate corresponds to one of the plurality of sensed atrial rates for which the AVD s value has been previously calculated but has expired, recalculating and storing the AVD s value for that sensed atrial rate; wherein the controller is configured to calculate a plurality of different AVD p values for each of a plurality of a paced atrial rates by: 1) operating in a ventricular pacing mode with atrial pacing, 2) varying the atrial pacing rate to corresponds to each of the plurality of paced atrial rates, and 3) calculating and storing an AVD p value for each paced atrial rate as a function of the intrinsic atrioventricular interval measured at each particular atrial pacing rate; and, wherein the controller is configured to automatically select one of the plurality of stored AVD s values and AVD p values based on an interval between atrial beats of consecutive cardiac cycles.