title: Circadian variation in ventricular tachycardia and atrial fibrillation in a medical-cardiological ICU.
abstract: OBJECTIVE
  To assess the diurnal distribution of ventricular tachycardia (VT) and atrial fibrillation (AF) in critically ill patients.
  
  
  METHODS
  Prospective observational study (episode-based design) in an eight-bed medical/cardiological ICU at a university hospital that also admits postoperative patients.
  
  
  METHODS
  98 consecutive patients with AF ( n=55) or ventricular tachycardia ( n=43).
  
  
  RESULTS
  There were a total of 218 arrhythmia episodes (83 AF, 136 VT). The time of arrhythmia onset was not evenly distributed. Circadian variation in VT but not AF onset was well represented by a sine wave function. Both VT and AF fibrillation showed a trough during the night. The distribution of VT and AF episodes did not differ significantly with or without analgosedation.
  
  
  CONCLUSIONS
  In critically ill patients the onset of VT and AF over 24-h is nonuniformly distributed. In VT this circadian pattern of occurrence is well modeled by a sine wave function peaking between noon and 2 p.m. The circadian pattern is less clear for AF. The circadian variation is seen irrespective of the presence of absence of analgosedation for both arrhythmias.
authors.affiliation: Department of Cardiology, University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria. georg.delle-karth@univie.ac.at.
authors.forename: Georg
authors.initials: G
authors.lastname: Delle Karth
authors.affiliation: Department of Cardiology, University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Reinelt
authors.affiliation: Department of Cardiology, University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
authors.forename: Anton
authors.initials: A
authors.lastname: Buberl
authors.affiliation: Department of Cardiology, University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Geppert
authors.affiliation: Department of Cardiology, University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Huelsmann
authors.affiliation: Department of Cardiology, University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Berger
authors.affiliation: Department of Cardiology, University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
authors.forename: Gottfried
authors.initials: G
authors.lastname: Heinz
mesh_terms: D018806:APACHE; D000368:Aged; D000700:Analgesics / Q000009:adverse effects; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D021081:Chronobiology Disorders / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D016638:Critical Illness; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000009:adverse effects; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D011446:Prospective Studies; D012121:Respiration, Artificial; D012307:Risk Factors; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D013997:Time Factors
chemical_list: D000700:Analgesics; D006993:Hypnotics and Sedatives