title: Age and gender influences on rate and duration of paroxysmal atrial fibrillation.
abstract: The influence of age and gender on the character of paroxysmal atrial fibrillation (PAD) has not been described.
  
  
  METHODS
  The heart rate (HR) during PAF in patients receiving placebo or antiarrhythmic therapy was analyzed. Data from 177 24-hour Holter recordings were analyzed to mark the onset and termination of PAF and converted into RR interval files. PAF episodes lasting at least 2 minutes and containing < or = 20% noise were included. HR during the first 30-second segment versus during the remainder of the episode, and the duration of PAF episodes were compared among groups of different ages and sex (Wilcoxon test).
  
  
  RESULTS
  236 episodes from 55 recordings in 32 patients (all patients: 61.4 +/- 12.8 years; men (19): 58.5 +/- 12.6 years; women (13) 65.5 +/- 12.4 years, P = ns for difference in age) fulfilled the inclusion criteria. Women had a higher mean heart rate at AF onset (123 +/- 35 beats/min vs 115 +/- 20 beats/min, P = 0.02) and during the remainder of the episode (120 +/- 25 beats/min vs 112 +/- 22 beats/min at the start, P = 0.01, and 116 +/- 26 beats/min vs 108 +/- 18 beats/min subsequently, P = 0.01). Episodes tended to be longer in women (mean 89.8 min vs 50.5 min, P = NS) and in the aged (mean 83.8 min vs 46.9 min, P = NS).
  
  
  CONCLUSIONS
  PAF episodes are associated with faster heart rates and last longer in women, which may reflect differing autonomic responses to AF. A slower ventricular rate during PAF in older patients probably reflects an increasing prevalence of impaired atrioventricular conduction.
authors.affiliation: Department of Cardiological Sciences, St. George's Hospital Medical School, London, England.
authors.forename: K
authors.initials: K
authors.lastname: Hnatkova
authors.forename: J E
authors.initials: JE
authors.lastname: Waktare
authors.forename: F D
authors.initials: FD
authors.lastname: Murgatroyd
authors.forename: X
authors.initials: X
authors.lastname: Guo
authors.forename: A J
authors.initials: AJ
authors.lastname: Camm
authors.forename: M
authors.initials: M
authors.lastname: Malik
mesh_terms: D000367:Age Factors; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001262:Atenolol / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000453:epidemiology* / Q000503:physiopathology; D018592:Cross-Over Studies; D004077:Digoxin / Q000627:therapeutic use; D004206:Disopyramide / Q000627:therapeutic use; D004311:Double-Blind Method; D015716:Electrocardiography, Ambulatory; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors
chemical_list: D000889:Anti-Arrhythmia Agents; D001262:Atenolol; D004077:Digoxin; D004206:Disopyramide