Patent ID: 8027725

Claim:
A method of operating a cardiac device to detect capture of a patient's heart, comprising: delivering one or more non-capturing electrical stimulation pulses to the heart; sensing one or more pacing artifact waveforms respectively associated with the one or more non-capturing electrical stimulation pulses; forming one or more pacing artifact templates using the one or more pacing artifact waveforms; after forming the one or more pacing artifact templates, delivering a subsequent electrical stimulation pulse to the heart; sensing a cardiac signal following the stimulation pulse; canceling a particular pacing artifact template of the one or more pacing artifact templates from the sensed cardiac signal to form a pacing artifact template cancelled signal; comparing the pacing artifact cancelled cardiac signal to an amplitude reference characterizing an amplitude of an evoked response; and detecting capture of the heart based on comparison of the pacing artifact cancelled cardiac signal and the amplitude reference.