title: Development of an alert system for subjects with paroxysmal atrial fibrillation.
abstract: BACKGROUND
  Knowledge of the onset of atrial fibrillation (AF) episodes in patients with paroxysmal atrial fibrillation (PAF) will enable them to better manage this condition. Current advances in mobile technology allow RR interval data to be obtained in real time. An analysis technique using RR interval data is presented with a view to alert a subject before a PAF episode.
  
  
  METHODS
  The method is based on a time series of standard deviation and 0.99 quantile values of the spectral entropy, constructed from RR data. The RR data are taken from three time periods. The first time period has no occurrences of AF for 45 min to either side of the time period. The second time period just precedes an AF attack. Both of these are of thirty minutes duration. The third time period of approximately 5 min follows the second, and is when AF occurs.
  
  
  RESULTS
  Twenty-two PAF subjects were studied and in all cases there was a steady increase in the values of these indices as the onset of the AF attack approached.
  
  
  CONCLUSIONS
  This method of analysis of RR interval data shows potential use to alert a PAF subject before the onset of an AF episode.
authors.affiliation: 1A, Russell Street, Eastwood, NSW 2122, Australia.
authors.forename: R A
authors.initials: RA
authors.lastname: Thuraisingham
keywords: Paroxysmal atrial fibrillation; RR interval; Spectral entropy; Standard deviation