title: Positive predictive value of device-detected atrial high-rate episodes at different rates and durations: an analysis from ASSERT.
abstract: BACKGROUND
  Pacemakers can automatically identify and catalog atrial high-rate episodes (AHREs). While most AHREs represent true atrial tachyarrhythmia/atrial fibrillation (AT/AF), a review of stored electrograms suggests that a substantial proportion do not. As AHREs may lead to the initiation of oral anticoagulation, it is crucial to understand the relationship between AHREs and true AT/AF.
  
  
  OBJECTIVE
  To compare the positive predictive value of AHREs for electrogram-confirmed AT/AF for various atrial rates and episode durations.
  
  
  METHODS
  By using data from 2580 patients who participated in the ASymptomatic atrial fibrillation and Stroke Evaluation in pacemaker patients and the AF Reduction atrial pacing Trial, all AHREs >6 minutes and >190 beats/min with available electrograms were reviewed to determine whether they represented true AT/AF. The positive predictive value of these AHREs was assessed for episode durations of 6 minutes, 30 minutes, 6 hours, and 24 hours at atrial rates of 190 and 250 beats/min.
  
  
  RESULTS
  Of 5769 AHREs >6 minutes and >190 beats/min, 82.7% were true AT/AF and 17.3% were false positives (predominantly due to repetitive non-re-entrant ventriculoatrial synchrony). False positives dropped to 6.8%, 3.3%, and 1.8% when the threshold duration was increased to 30 minutes, 6 hours, and 24 hours, respectively. Increasing the threshold heart rate to 250 beats/min added little to the positive predictive value when longer threshold durations were used.
  
  
  CONCLUSIONS
  By using a cutoff of >6 minutes and >190 beats/min, the rate of false-positive AHREs is 17.3%, making physician review of electrograms essential. For AHREs lasting >6 hours, the rate of false positives is 3.3%, making physician review less crucial.
authors.affiliation: Heart and Vascular Research Center, MetroHealth Campus of Case Western Reserve University, Cleveland, Ohio 44109, USA. ekaufman@metrohealth.org
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Kaufman
authors.forename: Carsten W
authors.initials: CW
authors.lastname: Israel
authors.forename: Girish M
authors.initials: GM
authors.lastname: Nair
authors.forename: Luciana
authors.initials: L
authors.lastname: Armaganijan
authors.forename: Syamkumar
authors.initials: S
authors.lastname: Divakaramenon
authors.forename: Georges H
authors.initials: GH
authors.lastname: Mairesse
authors.forename: Axel
authors.initials: A
authors.lastname: Brandes
authors.forename: Eugene
authors.initials: E
authors.lastname: Crystal
authors.forename: Otto
authors.initials: O
authors.lastname: Costantini
authors.forename: Roopinder K
authors.initials: RK
authors.lastname: Sandhu
authors.forename: Ratika
authors.initials: R
authors.lastname: Parkash
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Connolly
authors.forename: Stefan H
authors.initials: SH
authors.lastname: Hohnloser
authors.forename: Jeff S
authors.initials: JS
authors.lastname: Healey
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000175:diagnosis*; D017147:Defibrillators, Implantable; D005260:Female; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D011237:Predictive Value of Tests; D020521:Stroke / Q000209:etiology / Q000517:prevention & control; D013610:Tachycardia / Q000175:diagnosis*