title: Long-term characterization of persistent atrial fibrillation: wave morphology, frequency, and irregularity analysis.
abstract: Short-term properties of atrial fibrillation (AF) frequency, f-wave morphology, and irregularity parameters have been thoroughly studied, but not long-term properties. In the present work, f-wave morphology is characterized by principal component analysis, introducing a novel temporal parameter defined by the cumulative normalized variance of the three largest principal components (r3). Based on 7-day recordings from nine patients with stable chronic heart failure and persistent AF, long-term properties were studied in terms of r3 AF frequency, and sample entropy (SampEn). The main result of the present study is that detection of circadian rhythms depends on the parameter considered: rhythms were found in six (r3, SampEn) and five (AF frequency) patients, but not always in the same patient. Another important result is that circadian rhythms detected in 7-day recordings could not always be detected in 24-h periods, thus shedding new light on the results in previous studies which all were based on 24-h recordings. Infradian rhythms were found in four (r3, SampEn) and one (AF frequency) patients.
authors.affiliation: Department of Signal Theory and Communications, Rey Juan Carlos University, Camino del Molino s/n, 28943, Fuenlabrada, Spain, rebeca.goyaesteban@urjc.es.
authors.forename: Rebeca
authors.initials: R
authors.lastname: Goya-Esteban
authors.forename: Frida
authors.initials: F
authors.lastname: Sandberg
authors.forename: Óscar
authors.initials: Ó
authors.lastname: Barquero-Pérez
authors.forename: Arcadio
authors.initials: A
authors.lastname: García-Alberola
authors.forename: Leif
authors.initials: L
authors.lastname: Sörnmo
authors.forename: José Luis
authors.initials: JL
authors.lastname: Rojo-Álvarez
mesh_terms: D001281:Atrial Fibrillation / Q000503:physiopathology*; D002940:Circadian Rhythm / Q000502:physiology; D015716:Electrocardiography, Ambulatory / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D025341:Principal Component Analysis; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted