title: Heart rate variability findings as a predictor of atrial fibrillation in middle-aged population.
abstract: BACKGROUND
  Autonomic nervous system modifies atrial electrophysiologic properties and arrhythmia vulnerability.
  
  
  METHODS
  Heart rate (HR) variability, an indicator of cardiac autonomic regulation, was measured in 784 subjects (mean age 51 ± 6 years; 54% males) from a standardized 45-minute period in a study population (n = 1,045), which consisted of randomly selected hypertensive and age- and sex-matched control subjects at the time of recruitment in 1991-1992 (the OPERA study).
  
  
  RESULTS
  During a mean follow-up of 16.5 ± 3.5 years, 76 subjects (9.7%) had developed symptomatic atrial fibrillation (AF), needing hospitalization. HR did not predict the occurrence of AF. Among the various spectral and time-domain HR variability indexes, only the low-frequency (LF) spectral component independently predicted AF. In the Cox regression analysis, the hazard ratio of reduced HR corrected LF (LFccv ≤ 1.59%, optimal cutoff from the ROC curve) in predicting the AF was 3.28 (95% CI: 2.06-5.24; P < 0.001). In the multiple Cox regression model, including LFccv and other predictors of AF, such as age, gender, hypertension, history of coronary artery disease, systolic and diastolic blood pressure, body mass index, β-blocking, angiotensin converting enzyme inhibitor and aspirin medication, left atrial size, left ventricular mass index, and left ventricular size obtained by echocardiography, only LFccv (hazard ratio 2.81; 95% CI: 1.64-4.81; P < 0.001), age (P = 0.006), and systolic blood pressure (P = 0.02) remained as significant predictors of AF.
  
  
  CONCLUSIONS
  Impaired LF oscillation of HR predicts new-onset AF in a middle-aged population emphasizing the important role of autonomic nervous system in the genesis of symptomatic AF.
authors.affiliation: Medical Research Center, University Hospital of Oulu, University of Oulu, Oulu, Finland.
authors.forename: Juha
authors.initials: J
authors.lastname: Perkiömäki
authors.forename: Olavi
authors.initials: O
authors.lastname: Ukkola
authors.forename: Antti
authors.initials: A
authors.lastname: Kiviniemi
authors.forename: Mikko
authors.initials: M
authors.lastname: Tulppo
authors.forename: Antti
authors.initials: A
authors.lastname: Ylitalo
authors.forename: Y Antero
authors.initials: YA
authors.lastname: Kesäniemi
authors.forename: Heikki
authors.initials: H
authors.lastname: Huikuri
mesh_terms: D000367:Age Factors; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy; D001341:Autonomic Nervous System / Q000503:physiopathology*; D016022:Case-Control Studies; D015897:Comorbidity; D005260:Female; D006321:Heart / Q000294:innervation*; D006339:Heart Rate; D006760:Hospitalization; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012042:Registries; D012307:Risk Factors; D013997:Time Factors
keywords: atrial fibrillation; autonomic nervous system; heart rate; heart rate variability; hypertension