Patent ID: 8725255

Claim:
A system, comprising: a plurality of electrodes configured for at least sensing cardiac electrical activity and energy delivery; a signal processor coupled to the electrodes and configured to produce a cardiac signal vector on a polar plot that originates at an atrioventricular (AV) node of a subject's heart, the cardiac signal vector associated with all or a portion of one or more cardiac activation sequences; and a controller coupled to the electrodes and the signal processor, the controller configured to: adjust a pacing parameter to elicit a cardiac signal vector indicative of one of pacing-dominant cardiac activation and intrinsic-dominant cardiac activation, continue to adjust the pacing parameter to elicit a cardiac signal vector indicative of the other of the pacing-dominant cardiac activation and the intrinsic-dominant cardiac activation, detect a change in an axis angle or a magnitude of the cardiac signal vector in response to the adjustment of the pacing parameter, define the change in the axis angle or the magnitude of the cardiac signal vector as a transition between the pacing-dominant cardiac activation and intrinsic-dominant cardiac activation; and store the adjusted pacing parameters to define a transition region.