title: Paroxysmal atrial fibrillation: dynamics of the main antioxidant enzymes--superoxide dismutase and catalase.
abstract: Researchers have a particularly strong interest in the mechanisms implicated in the clinical manifestation of atrial fibrillation.
  
  
  
  To examine dynamically the activity of the antioxidant enzymes, superoxide dismutase and catalase in patients with paroxysmal atrial fibrillation (duration < 48 hours).
  
  
  
  The studied parameters were examined in the erythrocytes of 51 patients (59.84 +/- 1.60, 26 men) immediately after their hospitalization, at 24 hours and 28 days after restoration of sinus rhythm. 52 controls (59.50 +/- 1.46, 26 men) were also included, none of which had a history of arrhythmia. Propafenone was used to manage the rhythm abnormality. The enzyme activity was determined by a spectrophotometric method.
  
  
  
  The average duration of atrial fibrillation episodes until the time of hospitalization was 8.14 hours (from 2 to 24 hours). During patient hospitalization the activity of superoxide dismutase and catalase was considerably higher compared to that of the controls (8.46 +/- 0.26 vs 5.81 +/- 0.14 U/mg Hb; 7.36 +/- 0.25 vs 4.76 +/- 0.12 E240/min/mg Hb; P < 0.001). This difference was maintained 24 hours after the rhythm regularization (7.19 +/- 0.25 vs 5.81 +/- 0.14 U/mg Hb, p < 0.001; 5.30 +/- 0.21 vs 4.76 +/- 0.12 E240/min/mg Hb, p < 0.05). Twenty-eight days after the restoration of sinus rhythm, the activity of catalase remained increased (5.11 +/- 0.08 vs 4.76 +/- 0.12 E240/min/mg Hb, p < 0.05).
  
  
  
  The paroxysmal atrial fibrillation in our study was characterized with significantly increased activity of superoxide dismutase and catalase even in the early hours of clinical manifestation of the disorder, which then slowly decreased with the restoration of sinus rhythm. Therefore, we can conclude that changes in oxidative status are closely related to the disease and are probably a part of the intimate mechanisms related to its initiation and clinical course.
authors.affiliation: First Clinic of Cardiology
authors.forename: Mariya N
authors.initials: MN
authors.lastname: Negreva
authors.affiliation: First Clinic of Cardiology
authors.forename: Atanas P
authors.initials: AP
authors.lastname: Penev
authors.affiliation: Second Clinic of Cardiology, St. Marina University Hospital, Department of Internal Medicine, Training and Research Sector of Cardiology and Rheumatology, Prof. Dr. Paraskev Stoyanov Medical University, Varna
authors.forename: Svetoslav Zh
authors.initials: SZh
authors.lastname: Georgiev
authors.affiliation: Laboratory of Free Radical Processes, Institute of Neurobiology at Bulgarian Academy of Sciences, Sofia, Bulgaria
authors.forename: Albena A
authors.initials: AA
authors.lastname: Aleksandrova
mesh_terms: D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000201:enzymology*; D002374:Catalase / Q000097:blood*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011405:Propafenone / Q000627:therapeutic use; D013482:Superoxide Dismutase / Q000097:blood*
chemical_list: D000889:Anti-Arrhythmia Agents; D011405:Propafenone; D002374:Catalase; D013482:Superoxide Dismutase