Patent ID: 7908006

Claim:
A method of operating a cardiac medical device to automatically form a cardiac response classification interval during which a cardiac signal is sensed to determine a cardiac response of a heart to pacing, the method comprising: sensing one or more cardiac signals associated with a type of cardiac pacing response; determining timing variability of one or more features of the cardiac signals; forming the cardiac response classification interval including temporally orienting the classification interval with respect to timing of the one or more cardiac signal features, and setting a duration of the classification interval using the timing variability of the one or more cardiac signal features; determining the cardiac response to pacing using the classification interval; delivering pacing therapy to the heart based on determination of the cardiac pacing response; and determining whether a predetermined stability criterion has been achieved based on the variability of a parameter of the cardiac response classification interval being below a predetermined value; wherein forming the cardiac response classification interval comprises adapting an upper or lower bound of the classification interval until the predetermined stability criterion is determined to be achieved.