Cardiac monitoring and/or stimulation methods and systems that provide one
or more of monitoring, diagnosing, defibrillation, and pacing. Cardiac
signal separation is employed for automatic capture verification using
cardiac activation sequence information. Devices and methods sense
composite cardiac signals using implantable electrodes. A source
separation is performed using the composite signals. One or more signal
vectors are produced that are associated with all or a portion of one or
more cardiac activation sequences based on the source separation. A
cardiac response to the pacing pulses is classified using characteristics
associated with cardiac signal vectors and the signals associated with
the vectors. Further embodiments may involve classifying the cardiac
response as capture or non-capture, fusion or intrinsic cardiac activity.
The characteristics may include an angle or an angle change of the
cardiac signal vectors, such as a predetermined range of angles of the
one or more cardiac signal vectors.