title: Paradoxical atrial undersensing by a dual chamber pacemaker during atrial fibrillation.
abstract: This report describes paradoxical atrial undersensing by a dual chamber pacemaker in a patient with paroxysmal atrial fibrillation. Atrial undersensing was present only when the device was programmed to a high sensitivity but sensing normalized when a lower sensitivity was programmed. This unusual response should be differentiated from the recently documented lock-in behavior of pacemakers delivering managed ventricular pacing.
authors.affiliation: Florida Heart Rhythm Institute, Tampa, Florida, USA. ssbarold@aol.com
authors.forename: S Serge
authors.initials: SS
authors.lastname: Barold
authors.forename: Bengt
authors.initials: B
authors.lastname: Herweg
mesh_terms: D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D054537:Atrioventricular Block / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D002304:Cardiac Pacing, Artificial; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D004867:Equipment Design; D004868:Equipment Failure; D006325:Heart Atria / Q000503:physiopathology; D006801:Humans; D010138:Pacemaker, Artificial; D011237:Predictive Value of Tests; D012815:Signal Processing, Computer-Assisted