Patent ID: 8301251

Claim:
A method for detecting atrial tachyarrhythmia, comprising: sensing atrial events; detecting A-A intervals between the atrial depolarizations in a sequence of atrial depolarizations; identifying at least first and second A-A intervals of the sequence; selecting at least one A-A interval of the sequence for use in tachyarrhythmia detection based on information about the first A-A interval relative to the second A-A interval, wherein selecting the at least one A-A interval comprises at least one of comparing a duration of the first A-A interval to a duration of the second A-A interval, and determining whether the at least one A-A interval is an odd interval or an even interval in the sequence; operating at least one counter using the selected A-A interval; and detecting tachyarrhythmia based on an output of the counter.