Patent ID: 7512438

Claim:
An implantable device for tracking the cardiovascular condition of a human patient, the device including: at least two implanted electrodes that are positioned within the human patient to sense the electrical signal from the patient's heart, the electrical signal being an electrogram which consists of a multiplicity of beats; a processor to compute the value of at least one heart signal parameter for every beat of at least a portion of the multiplicity of beats of the electrogram; and digital memory designed to store the computed values of the at least one heart signal parameter during each of at least two time periods that are each at least one hour long, where said at least one heart signal parameter stored in said digital memory is the value of a QRS voltage, and the QRS voltage is indicative of the amplitude of the QRS complex; circuitry entirely contained within the implantable device indicating rejection of a heart transplanted into the human patient, the circuitry being configured for determining a pre-determined decrease in the median or mean value of a plurality of QRS voltages over a pre-determined time interval.