title: Pacemaker spike alternans: an artifact of digital signal processing.
abstract: Marked variability in the amplitude or polarity of pacemaker artifacts may be a clue to generator malfunction or partial electrode fracture. We report a case where "pacemaker spike alternans" occurred factitiously as a result of a digital "roll-over" effect. The widespread introduction of digital electrocardiographs into clinical practice makes recognition of such artifacts important.
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000209:etiology*; D003201:Computers; D003937:Diagnosis, Differential; D004562:Electrocardiography / Q000295:instrumentation*; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial