Embodiments of the present invention relate to implantable systems, and methods for use therewith, for monitoring myocardial electrical stability. A patients heart is paced for a period of time using a patterned pacing sequence that repeats every N beats, and an electrical signal is obtained that is representative of a plurality of consecutive beats of the patients heart while it is being paced using the patterned pacing sequence that repeats every N beats. Myocardial electrical stability is then analyzed using frequency domain techniques that are tailored to the patterned pacing sequence used to pace the patients heart. In other embodiments, the patients heart need not be paced. This abstract is not intended to be a complete description of, or limit the scope of, the invention.