A system and method for performing off-line analysis of cardiac electrogram data, comprising: retrieving an electrogram from a memory location; identifying a first-channel group of candidate beats from at least a first channel of the electrogram; and identifying a second-channel group of candidate beats from at least a second channel of an electrogram. For each first-channel beat candidate near a second-channel beat candidate, the amplitude of the first-channel beat candidate is compared with the amplitude of a previous beat and the amplitude of a next beat on the first electrogram channel, and first-channel beat candidates that are outside of a first pre-determined range from either the previous or next beat are removed. Then first-channel beat candidates that are outside of a second pre-determined range from either the previous or next beat candidate are removed.