title: Ventricular pauses during atrial fibrillation predict relapse after electrical cardioversion: a prospective study.
abstract: OBJECTIVE
  To investigate the use of ambulatory electrocardiogram (ECG) monitoring in atrial fibrillation (AF) to predict recurrence after electrical cardioversion (ECV).
  
  
  METHODS
  RR interval variables were obtained from 24 hours ECGs recorded before ECV in 119 patients (85 men, age 66 +/- 10 years) with persistent AF. Patients were followed for 1 month.
  
  
  RESULTS
  Of the 119 patients, 16 (13%) failed ECV and 65 (55%) were in AF at 1 week and 81 (68%) at 1 month after ECV. The maximum RR interval (RR-max) and the minimum RR interval (RR-min) during AF were found to be reproducible. The RR-max was longer in those who had AF 1 week (2.55 +/- 0.49 vs 2.01 +/- 0.52 seconds, P = 0.005) and 1 month (2.56 +/- 0.50 vs 1.89 +/- 0.43 ms; P < 0.001) after ECV than in those who maintained sinus rhythm. Those in AF at 1 month included more patients with RR-max > or = 2.8 seconds (31% vs 11% P = 0.021). The average heart rate was lower in patients with RR-max > or = 2.8 seconds, but the average rate was not predictive of AF recurrence.
  
  
  CONCLUSIONS
  Ventricular pauses during AF predict relapse after ECV.
authors.affiliation: Division of Cardiac & Vascular Sciences, St George's Hospital, University of London, London, United Kingdom. mark_m_gallagher@hotmail.com
authors.forename: Mark Michael
authors.initials: MM
authors.lastname: Gallagher
authors.forename: Xiao Hua
authors.initials: XH
authors.lastname: Guo
authors.forename: Jan
authors.initials: J
authors.lastname: Poloniecki
authors.forename: A John
authors.initials: AJ
authors.lastname: Camm
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000628:therapy*; D004554:Electric Countershock; D015716:Electrocardiography, Ambulatory; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D012008:Recurrence; D016276:Ventricular Function