title: Demand pacemaker arrhythmias caused by intermittent incomplete electrode fracture. Diagnosis with testing magnet.
abstract: This report describes how the testing magnet was used to diagnose intermittent and incomplete electrode fracture in two patients with an implanted demand pacemaker. During fixed-rate pacing the interval between two consecutive pacemaker spikes intermittently doubled in length, suggesting that the pulse generator was continuing to fire on time into a transiently disrupted circuit. Attenuated pacemaker spikes occurring at the anticipated time of pacemaker discharge also provided a diagnostic clue. Ventricular electrograms from the defective electrodes registered small false signals.
mesh_terms: D000328:Adult; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D005117:Cardiac Complexes, Premature / Q000175:diagnosis; D003937:Diagnosis, Differential; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008280:Magnetics; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial / Q000009:adverse effects* / Q000295:instrumentation