title: Abrupt changes in fibrillatory wave characteristics at the termination of paroxysmal atrial fibrillation in humans.
abstract: OBJECTIVE
  We investigated the process of spontaneous termination of atrial fibrillation (AF) to determine its time course from the surface ECG.
  
  
  RESULTS
  We studied fibrillatory waves in Holter recordings of paroxysmal and sustained AF. Following QRS-T cancellation dominant frequencies (DFs) were computed and the relationship of DF to termination was scrutinized. For 57 episodes of paroxysmal AF (PAF) in 24 patients, DF ranged from 4.4 to 6.5 Hz (5.2 +/- 0.4 Hz) compared to 5.8 to 7.4 Hz (6.6 +/- 0.6 Hz) for sustained AF recordings. Comparison of the atrial frequency of the ultimate to the penultimate second demonstrated a drop in frequency in 51 of 57 episodes, P < 0.00001. No comparable change was seen at longer time periods. Moments of comparably low frequency without termination were only occasionally seen in patients with PAF but not in patients with sustained AF.
  
  
  CONCLUSIONS
  Low frequency fibrillation was found to be much more likely to terminate. Frequency changes preceding spontaneous termination were abrupt, in contrast to the gradual frequency drop reported with drug-induced termination. The analysis of fibrillatory wave characteristics and their change over time might be used to target specific moments for pacing therapy in patients with AF.
authors.affiliation: Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, USA.
authors.forename: Simona
authors.initials: S
authors.lastname: Petrutiu
authors.forename: Alan V
authors.initials: AV
authors.lastname: Sahakian
authors.forename: Steven
authors.initials: S
authors.lastname: Swiryn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000503:physiopathology*; D015716:Electrocardiography, Ambulatory; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012815:Signal Processing, Computer-Assisted