Patent ID: 6922584

Claim:
A method for discriminating heart rhythms in an implantable medical device, comprising the steps of: receiving a QRS interval corresponding to the heart rhythm and computing a first predetermined number of RR intervals from the received QRS intervals; computing a median RR interval corresponding to a predetermined number of the first predetermined number of RR intervals; determining a rate zone in response to the computed median RR interval; determining a predetermined beat-to-beat variation corresponding to the rate zone; varying a count in response to the rate zone and the predetermined beat-to-beat variation; computing beat-to-beat variation differences between the first predetermined number of RR intervals; comparing the beat-to-beat variation differences to the predetermined beat-to-beat variation to determine whether the number of the computed beat-to-beat variation differences greater than the predetermined beat-to-beat variation is greater than the count; and identifying the heart rhythm in response to the number of the computed beat-to-beat variation differences relative to the count.