Patent ID: 8626276

Claim:
A system, comprising: a housing configured for implantation in a patient; a plurality of implantable electrodes configured for sensing a plurality of composite signals associated with an unknown number of signal sources; a memory provided in the housing and configured to store a baseline angular orientation of a cardiac signal vector representative of the patient's baseline ischemia status; and a processor provided in the housing and coupled to the electrodes and the memory, the processor configured to: open a window associated with an ST-T segment within which the plurality of composite signals are sensed for each of a plurality of cardiac cycles; perform recurring source separation operations by which the plurality of composite signals sensed within the window are separated according to their respective sources to produce windowed cardiac signal vectors indicating a dominant angular orientation of repolarization wavefronts over the plurality of cardiac cycles; and detect a deviation in the dominant angular orientation of the windowed cardiac signal vectors relative to the baseline angular orientation as an indication of a change in the patient's ischemia status relative to the patient's baseline ischemia status.