title: Pseudo-oversensing of the T wave by an implantable cardioverter defibrillator: a nonclinical problem.
abstract: Two patients are described who had pseudo-oversensing of T waves during follow-up testing of the Medtronic PCD. Each patient exhibited appropriate T wave sensing following closely coupled spontaneous QRS complexes to subthreshold stimuli without having T wave sensing following sensed or paced complexes. One patient also revealed T wave sensing following fusion beats. The occurrence of T wave sensing in these unique clinical situations was due to the auto-adjusting sensitivity threshold function used by the PCD. Recognition of this normal sensing function will prevent inappropriate reprogramming of the sensitivity or postpace refractory period, interventions that could potentially lead to ventricular tachyarrhythmia undersensing.
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota 55905.
authors.forename: D W
authors.initials: DW
authors.lastname: Frazier
authors.forename: M S
authors.initials: MS
authors.lastname: Stanton
mesh_terms: D000328:Adult; D001145:Arrhythmias, Cardiac / Q000628:therapy; D002312:Cardiomyopathy, Hypertrophic / Q000503:physiopathology; D017147:Defibrillators, Implantable; D004562:Electrocardiography; D004582:Electronics, Medical; D004867:Equipment Design; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000503:physiopathology; D012032:Refractory Period, Electrophysiological / Q000502:physiology; D012680:Sensitivity and Specificity; D017180:Tachycardia, Ventricular / Q000628:therapy