Patent ID: 8478407

Claim:
A method for rate adaptive cardiac pacing that employs implanted electrodes for single chamber pacing and sensing and one or more rate response sensors; and the method comprising the steps of: establishing a baseline rate for pacing stimulation according to input from the one or more rate response sensors; establishing an offset rate for pacing stimulation, the offset rate being lower than the baseline rate and generally tracking therewith such that a difference between the baseline rate and the offset rate remains substantially constant over time; sensing for intrinsic events by means of the implanted electrodes; applying a pacing stimulation pulse by means of the implanted electrodes, when an intrinsic event is not detected within a time interval necessary to at least maintain the offset rate, the applied pacing stimulation pulse creating a paced event to maintain the offset rate; switching from the offset rate to the baseline rate and pacing at the baseline rate over a predetermined period of time, when x of y successive events are paced events, x being greater than one and y being greater than or equal to x; and at the end of the predetermined period of time, again sensing for intrinsic events, and repeating the above last two steps; wherein the offset rate is established according to a predetermined decrement of one of: the baseline rate; and a greater of the baseline rate and an intrinsic rate, the intrinsic rate being determined by the sensing for intrinsic events; and further comprising: establishing a preference rate that falls between the baseline rate and the offset rate; and switching from the offset rate to the baseline rate and pacing at the baseline rate over the predetermined period of time, when the rates of successive intrinsic events, over a predetermined interval, even if greater than the offset rate, meet a criterion with respect to the preference rate, the criterion being one of: x of y successive intrinsic events falling below the preference rate over the predetermined interval, x being greater than one and y being greater than or equal to x; and a measure of central tendency of the rates of successive intrinsic events falling below the preference rate over the predetermined interval.