title: Pacing alternans: an unusual pattern of pacemaker behavior.
abstract: We report an unusual pattern of pacemaker function related to the "autocapture" feature of a recently released pacemaker model. The electrocardiogram reveals pacing alternans. This report discusses the differential diagnosis and the correct explanation.
authors.affiliation: Hospital of the University of Pennsylvania, 3400 Spruce St., Philadelphia, PA, USA.
authors.forename: B B
authors.initials: BB
authors.lastname: Pavri
authors.forename: J M
authors.initials: JM
authors.lastname: Keefe
authors.forename: D J
authors.initials: DJ
authors.lastname: Callans
authors.forename: D Z
authors.initials: DZ
authors.lastname: Kocovic
mesh_terms: D000465:Algorithms; D002340:Carotid Artery Diseases / Q000503:physiopathology / Q000628:therapy; D002346:Carotid Sinus / Q000503:physiopathology; D004562:Electrocardiography; D004868:Equipment Failure; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial / Q000009:adverse effects*; D011930:Reaction Time; D012684:Sensory Thresholds; D013577:Syndrome