Patent ID: 7765004

Claim:
A method for detecting cardiac signal noise during capture verification, comprising: delivering a pacing pulse to a heart chamber; sensing a cardiac signal associated with the pacing pulse; classifying a cardiac response to the pacing pulse based on the sensed cardiac signal, the cardiac response classification being one of a plurality of expected cardiac responses including capture and intrinsic activation; sensing for unexpected signal content in the cardiac signal, the unexpected signal content being inconsistent with one or more of capture and intrinsic activation and comprising one or more of unexpected signal peaks, the one or more unexpected cardiac signal peaks having an opposite polarity relative to a polarity of one or more cardiac signal peaks indicative of capture or intrinsic activation; and determining that the cardiac response classification is possibly erroneous if the unexpected signal content is detected, wherein at least one of delivering, classifying, and determining is implemented at least in part by circuitry.