title: Orthogonal electrogram sensing.
abstract: Intracardiac electrogram sensing is the afferent limb of demand pacing systems. Under- and over-sensing at the ventricular level has been demonstrated in almost 50% of implanted unipolar pulse generators, and atrial electrogram sensing problems are more common. A unique dedicated sensor employing noncontacting and circumferentially placed orthogonal electrodes was tested at both the atrial and ventricular levels. Electrograms demonstrated voltages similar to those recorded from contacting electrodes, but with complete far-field rejection of signals from the opposite chamber. Orthogonal electrograms allowed for activation sequencing and capture verification as well.
mesh_terms: D004553:Electric Conductivity; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D004594:Electrophysiology; D006325:Heart Atria / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D009206:Myocardium / Q000473:pathology; D010138:Pacemaker, Artificial / Q000009:adverse effects*