According to some methods for example preprogrammed in a microprocessor element of an implantable cardiac pacing system at least one of a number of periodic pacing threshold searches includes steps to reduce an evoked response amplitude threshold for evoked response signal detection. The reduction may be to a minimum value measurable above zero for example as determined by establishing a noise floor . Alternately amplitudes of test pacing pulses and corresponding post pulse signals are collected and reviewed to search for a break to determine a lower value to which the evoked response threshold may be adjusted without detecting noise. Subsequent to reducing the threshold if no evoked response signal is detected for a test pulse applied at or above a predetermined maximum desirable pulse energy an operational pacing pulse energy is set to greater than or equal to the maximum desirable in conjunction with a reduction in pacing rate.