title: Atrial fibrillation activates platelets and coagulation in a time-dependent manner: a study in patients with paroxysmal atrial fibrillation.
abstract: OBJECTIVE
  To determine whether atrial fibrillation (AF) alone affects the fibrinocoagulation system, we examined the relation between fibrinocoagulation activity and duration of AF in patients with paroxysmal AF (PAF).
  
  
  BACKGROUND
  Patients with chronic AF are at higher risk for stroke and a hypercoagulative state. It is not clear whether this hypercoagulative state is attributable to AF alone or to the underlying disease. There are no reports on the fibrinocoagulation properties in PAF.
  
  
  METHODS
  Fibrinocoagulation variables in 21 patients with PAF were measured during AF and 7 days after recovery of sinus rhythm. There were positive correlations between the duration of AF and beta-thromboglobulin, platelet factor 4, thrombin-antithrombin III complex and fibrinogen. These variables increased significantly 12 h after the occurrence of PAF; thus, patients were classified into two groups according to the duration of PAF: PAF-I group (< 12 h, n = 10), PAF-II group (> or = 12 h, n = 11). Nine age-matched, healthy subjects formed the control group.
  
  
  RESULTS
  Levels of beta-thromboglobulin and platelet factor 4 were significantly higher (p < 0.001) by two-way repeated measures analysis of variance (ANOVA), and thrombin-antithrombin III complex and fibrinogen levels tended to be but were not significantly higher (p = 0.06, ANOVA), in the PAF-II group than in the PAF-I group. There were no significant differences between groups in activated partial thromboplastin time, D-dimer or plasmin inhibitor complex.
  
  
  CONCLUSIONS
  These results indicate that AF itself enhances platelet aggregation and coagulation, which are influenced by the duration of AF. The acceleration of platelet activity and coagulability occurred 12 h after the occurrence of AF.
authors.affiliation: Division of Cardiology, Shinkyo Hospital, Kagoshima, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sohara
authors.forename: S
authors.initials: S
authors.lastname: Amitani
authors.forename: M
authors.initials: M
authors.lastname: Kurose
authors.forename: K
authors.initials: K
authors.lastname: Miyahara
mesh_terms: D000704:Analysis of Variance; D001281:Atrial Fibrillation / Q000097:blood* / Q000150:complications; D001777:Blood Coagulation; D001779:Blood Coagulation Factors / Q000032:analysis; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D006801:Humans; D002542:Intracranial Embolism and Thrombosis / Q000453:epidemiology / Q000209:etiology; D008297:Male; D008875:Middle Aged; D015539:Platelet Activation; D012307:Risk Factors; D013997:Time Factors
chemical_list: D001779:Blood Coagulation Factors