title: Evolution of changes in the ventricular rhythm during paroxysmal atrial fibrillation.
abstract: Changes in the RR interval within episodes of paroxysmal atrial fibrillation (PAF) have not been fully characterized. A database of 177 24-hour Holter recordings were created from patients with PAF in the CRAFT studies. PAF episodes of > or = 1 minute duration containing < or = 20% noise and preceded by > or = 1 minute of sinus rhythm with < or = 20% noise were selected. Sections of each AF episode containing 10 and 25 RR intervals were identified at the onset, middle, and termination of each episode. Descriptive characteristics (mean, SD, and RMSSD of RR intervals) were calculated within each section, and compared using a nonparametric, paired Wilcoxon test. In 25 patients (17 men, 60.6 +/- 12.2 years old), 231 episodes from 44 recordings met the selection criteria. The mean RR interval increased slightly between the onset and mid-portion of AF episodes (565.9 +/- 128.3 vs 580.3 +/- 144.7 ms, P < 0.001). The RR interval at the termination of AF was significantly greater than that at the start (627.1 +/- 156.1 vs 565.9 ms, P < 10-11) or mid-portion (627.1 +/- 156.1 vs 580.3 +/- 144.7 ms, P < 10-13). SD of the RR interval increased significantly between onset and mid-portion (111.1 +/- 60.2 vs 118.2 +/- 66.7 ms, P < 0.001) and more substantially between mid-portion and termination (118.2 +/- 66.7 vs 201.8 +/- 93.7 ms, P < 10-21). During paroxysms of AF, the mean RR interval and the variability of RR intervals increases. Termination of a paroxysm is preceded by a marked increase in RR interval variability.
authors.affiliation: Department of Cardiological Sciences, St. George's Hospital Medical School, London, England. gallagh6sghms.ac.uk
authors.forename: M M
authors.initials: MM
authors.lastname: Gallagher
authors.forename: K
authors.initials: K
authors.lastname: Hnatkova
authors.forename: F D
authors.initials: FD
authors.lastname: Murgatroyd
authors.forename: J E
authors.initials: JE
authors.lastname: Waktare
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: D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001262:Atenolol / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000188:drug therapy / 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; D013997:Time Factors
chemical_list: D000889:Anti-Arrhythmia Agents; D001262:Atenolol; D004077:Digoxin; D004206:Disopyramide