Patent ID: 8452404

Claim:
An implantable medical device including: at least one electrode adapted to be located within the heart to sense an electrical signal from the heart; electrical circuitry configured to amplify and digitize the electrical signal; memory storage coupled to the electrical circuitry for storing the digitized electrical signal; a processor configured to: distinguish between supraventricular beats and ventricularly paced beats; identify which of at least three pacing modes of operation is active at any time, wherein a first pacing mode is identified when the number of ventricularly paced beats is sufficiently small to meet a first criterion and ischemic event is identified based on supraventricular beats, wherein a second pacing mode is identified when the number of supraventricular beats is sufficiently small to meet a second criterion and ischemic event is identified based on ventricularly paced beats, and a third pacing mode is identified when the number of ventricularly paced beats and the number of supraventricular beats are large that neither the first nor the second criteria are met and ischemic event is identified as a function of supraventricular beats and ventricularly paced beats; identify ischemic events by implementing an ischemia detection protocol specific to that mode, and applying the ischemia detection protocol to the digitized electrical signal.