Patent ID: 8855755

Claim:
An implantable medical device (IMD) comprising: a sensing module configured to acquire signals associated with a plurality of cardiac events cardiac events of a heart of a patient via at least one sensor; and a processor configured to compute a plurality of cardiac event intervals, wherein each of the cardiac event intervals corresponds to an amount of time between successive ones of the plurality of cardiac events, detect rate onset of a rhythm of the heart of the patient based at least on one of relative changes and variations over the plurality of cardiac event intervals, identify a location of the initiation of rate onset among the plurality of cardiac events used to compute the plurality of cardiac event intervals used for detection of the rate onset, obtain an electrogram (EGM) of one of the cardiac events of the plurality of cardiac events used to compute the plurality of cardiac event intervals used for detection of the rate onset and located subsequent to the after a location of the initiation of the rate onset, analyze a morphology of the obtained EGM associated with the cardiac event after the location of the initiation of the rate onset, and determine whether the rhythm is indicative of a treatable rhythm based on the analysis of the morphology of the obtained EGM.