Patent ID: 7555340

Claim:
A method for operating a cardiac rhythm management device in a patient, comprising: delivering paces to the left ventricle in accordance with a programmed pacing mode for pre-exciting the left ventricle, such that a left ventricular pace is delivered after a programmed AV delay interval with respect to an atrial event; and, determining an optimum AV delay interval by: recording an evoked response electrogram during a paced cardiac cycle with a short AV delay interval expected to be shorter than the patient's intrinsic atrioventricular interval to ensure that paced excitation of both ventricles occurs before intrinsic activation; incrementing the AV delay interval by a predetermined amount and recording an evoked response electrogram during a paced cardiac cycle with the incremented AV delay interval; comparing the evoked response electrograms recorded with the incremented and short AV delay intervals; continuing to increment the AV delay interval by the predetermined amount until the evoked response electrogram recorded with the incremented AV delay interval differs from the evoked response electrogram recorded with the short AV delay interval by a specified amount so as to indicate the occurrence of fusion beat that includes paced excitation of the left ventricle and intrinsic activation of the right ventricle; and, determining the optimum AV delay interval as the incremented AV delay interval used when the fusion beat occurs.