Patent ID: RE40670

Claim:
A method for operating a cardiac pacemaker in resynchronization pacing mode, comprising: sensing rate and synchronized heart chambers through separate channels and generating sense signals upon detection of depolarization occurring in a chamber; pacing the rate chamber in accordance with bradycardia pacing mode based upon rate chamber senses and paces; pacing the synchronized chamber in accordance with a resynchronization pacing mode; measuring a rate chamber event interval for each cardiac cycle, wherein the interval is the time between the chamber senses and paces that define a cardiac cycle; counting the number of senses and paces occurring in each rate and synchronized chamber for a specified period of time and assigning each counted sense or pace to an interval bin representing the rate chamber event interval for that cardiac cycle so that each interval bin contains a sense count and a pace count for each chamber; calculating an event frequency for the senses and paces in each interval bin over the specified period of time by dividing the sense and pace count in each bin by a denominator equal to the sum of the total sense counts for the rate chamber, the total pace counts for the rate chamber, and the total pace counts for the synchronized chamber only for those cardiac cycles in which no pace was delivered to the rate chamber.