Patent ID: 7991471

Claim:
A method of treating a cardiac event of a heart generating a cardiac signal representative of at least one of a plurality of depolarizations of the heart and a plurality of repolarizations of the heart, the treating of the cardiac event being conducted by a medical device having a plurality of electrodes and therapeutic componentry having an armed state and an unarmed state, comprising: sensing the cardiac signal with the plurality of electrodes while the therapeutic componentry is in the unarmed state, the plurality of electrodes forming a first sensing vector and a second sensing vector; if at least one of a plurality of intervals between ones of the at least one of a plurality of depolarizations of the heart and the at least one of the plurality of repolarizations of the heart sensed along at least one of the first sensing vector and the second sensing vector is less than a predetermined threshold corresponding to the cardiac event; then determining a reliability of the first sensing vector and the second sensing vector based, at least in part, on: a first subset of the plurality of intervals sensed only by the first sensing vector and relative to a predetermined threshold and a second subset of the plurality of intervals sensed only by the second sensing vector and relative to the predetermined threshold, respectively; and a morphology of a subset of the plurality of depolarizations of the heart and the plurality of repolarizations of the heart sensed only by the first sensing vector and only by the second sensing vector, respectively; and if the first sensing vector is reliable and the second sensing vector is reliable, advancing the therapeutic componentry to the armed state based, at least in part, on a heart rate defined by at least one of the plurality of intervals sensed only by the first sensing vector and at least one of the plurality of intervals sensed only by the second sensing vector simultaneously with the first sensing vector; else if only one of the first sensing vector and the second sensing vector is reliable, advancing the therapeutic componentry to the armed state based, at least in part, on a heart rate defined by at least one of the plurality of intervals sensed only by the one of the first sensing vector and the second sensing vector which is reliable.