Patent ID: 8140157

Claim:
An implantable medical device comprising: a pulse generator that emits cardiac stimulation pulses; at least one medical lead connected to said pulse generator that delivers said stimulating pulses in vivo to cardiac tissue of a heart of a patient; an impedance measuring circuit that, during impedance measurement sessions, generates electrical signals applied between at least a first electrode and a second electrode, among electrodes carried by said at least one medical lead, in at least two electrode configurations according to a predetermined scheme, and that measures impedance in the tissue between said first electrode and said second electrode of each of said at least two electrode configurations; and an ischemia detector that evaluates the measured impedances by comparing the measured impedances with at least one reference impedance image of the heart comprising a plurality of impedance regions, to detect changes in the measured impedances that are consistent with ischemia, and that determines a location of said ischemia with respect to at least one of said regions.