Patent ID: 8512257

Claim:
A system for detecting a cardiac event in a human patient, the system including: at least two implantable sensors for sensing cardiac signals from the patient's heart; an implantable device for detecting the cardiac event, the device including a processor configured to: periodically process segments of the cardiac signals from the patient's heart such that successive processed segments are separated by periods where heart parameters are not processed and have a selected duration that is adaptively selected by the processor; calculate a plurality of heart signal parameter values corresponding to a like plurality of heart beats during each processed segment; identify changes in the plurality of heart signal parameter values within a processed segment that meet at least one ischemia detection criterion; calculate heart rhythm information from the plurality of heart beats within the processed segment; apply at least one arrhythmia detection criterion to the heart rhythm information; and upon determining that either the ischemia detection criterion or the arrhythmia detection criterion have been met, changing the selected duration between successive processed segments dependent upon a predetermined number of said ischemia detection or the arrhythmia detection criteria being met.