Patent ID: 7761142

Claim:
A method of detecting a cardiac event with a medical device comprising a plurality of electrodes forming a first sensing vector and a second sensing vector, comprising: sensing cardiac signals from the plurality of electrodes; determining a first number of inflections of the sensed cardiac signals sensed along the first sensing vector; determining a second number of inflections of the sensed cardiac signals sensed along the second sensing vector; generating a first pulse amplitude threshold based, at least in part, on the first number of inflections and a second pulse amplitude threshold based, at least in part, on the second number of inflections; identifying the first sensing vector as one of noisy and not noisy based, at least in part, on the first number of inflections and the first pulse amplitude threshold; identifying the second sensing vector as one of noisy and not noisy based, at least in part, on the second number of inflections and the second pulse amplitude threshold; and delivering therapy based, at least in part, on the identifying of the first sensing vector as one of noisy and not noisy and the identifying of the second sensing vector as one of noisy and not noisy.