Methods and systems for detecting capture using pacing artifact
cancellation are described. One or more pacing artifact templates are
provided and a cardiac signal is sensed in a cardiac verification window.
Each of the pacing artifact templates may characterize the pacing
artifact associated with a particular pacing energy level, for example. A
particular pacing artifact template is canceled from the cardiac signal.
Capture is determined using the pacing artifact canceled cardiac signal.
Detection of fusion/pseudofusion beats may be accomplished by comparing a
cardiac signal to a captured response template.