Patent ID: 7099716

Claim:
An implantable cardiac stimulation device for stimulating a patient's heart through at least one electrode in electrical communication with selected cardiac tissue, the stimulation device comprising: a pulse generator that is configured to generate stimulation pulses at a selected amplitude for delivery to the at least one electrode; a detection circuit that is configured to process cardiac signals to determine a presence or absence of an evoked response to each of the stimulation pulses; and a controller coupled to the pulse generator, wherein the controller is operative to increase the amplitude of the stimulation pulses when an absence of evoked responses from at least X out of the last Y stimulation pulses exists, where Y is a value greater than 2 and X is a value less than Y, and wherein the controller is operative to maintain the amplitude of the stimulation pulses where there is no absence of evoked responses from X out of the last Y stimulation pulses.