title: Automated detection of atrial fibrillation from the electrocardiogram channel of polysomnograms.
abstract: OBJECTIVE
  Accurate identification of atrial fibrillation episodes from polysomnograms is important for research purposes but requires manual review of a large number of long electrocardiographic tracings. As automated assessment of these tracings for atrial fibrillation may improve efficiency, this study aimed to evaluate this approach in polysomnogram-derived electrocardiographic data.
  
  
  METHODS
  A previously described algorithm to detect atrial fibrillation from single-lead electrocardiograms was applied to polysomnograms from a large epidemiologic study of obstructive sleep apnea in older men (Osteoporotic Fractures in Men [MrOS] Sleep Study). Atrial fibrillation status during each participant's PSG was determined by independent manual review. Models to predict atrial fibrillation status from a combination of algorithm output and clinical/polysomnographic characteristics were developed, and their accuracy was evaluated using standard statistical techniques.
  
  
  RESULTS
  Derivation and validation cohorts each consisted of 1395 individuals; 5 % of each group had atrial fibrillation. Model parameters were optimized for the derivation cohort using the Akaike information criterion. Application to the validation cohort of these optimized models revealed high sensitivity (85-90 %) and specificity (90-95 %) as well as good predictive ability, as assessed by the C statistic (>0.9) and generalized R (2) values (∼0.6). Addition of cardiovascular or polysomnogram data to the models did not improve their performance.
  
  
  CONCLUSIONS
  In a research setting, automated detection of atrial fibrillation from polysomnogram-derived electrocardiographic signals appears feasible and agrees well with manual identification. Future studies can evaluate the utility of this technique as applied to clinical polysomnograms and ambulatory electrocardiographic monitoring.
authors.affiliation: Division of Cardiovascular Medicine, Vanderbilt Medical Center, 1215 21st Avenue-5th Floor-Medical Center East, Nashville, TN, 37232, USA. ken.monahan@vanderbilt.edu.
authors.forename: Ken
authors.initials: K
authors.lastname: Monahan
authors.affiliation: Department of Biostatistics, Vanderbilt Medical Center, Nashville, TN, USA.
authors.forename: Yanna
authors.initials: Y
authors.lastname: Song
authors.affiliation: Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, OH, USA.
authors.forename: Ken
authors.initials: K
authors.lastname: Loparo
authors.affiliation: Division of Sleep Medicine, Cleveland Clinic Foundation, Cleveland, OH, USA.
authors.forename: Reena
authors.initials: R
authors.lastname: Mehra
authors.affiliation: Department of Biostatistics, Vanderbilt Medical Center, Nashville, TN, USA.
authors.forename: Frank E
authors.initials: FE
authors.lastname: Harrell
authors.affiliation: Division of Sleep Medicine, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Redline
mesh_terms: D000368:Aged; D000465:Algorithms; D001281:Atrial Fibrillation / Q000175:diagnosis*; D015331:Cohort Studies; D003936:Diagnosis, Computer-Assisted; D004562:Electrocardiography; D006801:Humans; D008297:Male; D015233:Models, Statistical; D010024:Osteoporosis / Q000503:physiopathology; D017286:Polysomnography; D011237:Predictive Value of Tests; D012815:Signal Processing, Computer-Assisted; D020182:Sleep Apnea, Central / Q000175:diagnosis*; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis*
keywords: Atrial fibrillation; Polysomnography; RR intervals; Statistical modeling