An implantable cardiac stimulation system capable of automatic capture
verification is provided with an associated method for performing
automatic testing functions using programmable, or automatically
determined, atrioventricular delays. Automatic threshold testing and
evoked response sensitivity testing performed at a user-specified delay
setting, rather than a preset setting, allows assessment of automatic
capture verification based on an atrioventricular delay relevant to daily
system function. Further features of the present invention are an
adjustable frequency with which automatic threshold tests are performed
and an adjustable frequency with which threshold test results are stored
in memory in a threshold record for better monitoring of lead stability or
impending clinical problems. The frequency of performing threshold tests
and the frequency of storing threshold test results may be varied
according to the threshold stability. Stored threshold test results are
advantageously displayed with respect to a fixed or variable time scale.