title: Circadian rhythm in the cardiovascular system: chronocardiology.
abstract: BACKGROUND
  We reviewed recent progress in the study of the chronobiological aspects of the cardiovascular system.
  
  
  METHODS
  Medline was used as the main search tool, and the full texts of selected papers were obtained.
  
  
  RESULTS
  More than 300 references were found, and 52 of them, representing the major findings in this field, were included in the reference list. Results of these studies confirm that most cardiovascular physiological parameters (such as heart rate, blood pressure, electrocardiogram indices) and pathophysiological events (myocardial ischemia/infarction, sudden cardiac death) show circadian rhythms. Results also suggest that consideration of these rhythms is important for the diagnosis and treatment of cardiovascular disorders and that restoration of normal circadian rhythms may be associated with clinical improvement.
  
  
  CONCLUSIONS
  The study of circadian rhythms in the cardiovascular system is emerging as an important area of investigation because of its potential implications for patient management.
authors.affiliation: Cardiology Division in Geriatric Institute, Hebei Provincial People's Hospital, Shijiazhuang, China. guoyifang@hotmail.com
authors.forename: Yi-Fang
authors.initials: YF
authors.lastname: Guo
authors.forename: Phyllis K
authors.initials: PK
authors.lastname: Stein
mesh_terms: D001145:Arrhythmias, Cardiac / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D002395:Catecholamines / Q000097:blood; D002940:Circadian Rhythm / Q000502:physiology*; D003331:Coronary Vessels / Q000502:physiology; D004730:Endothelium, Vascular / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006487:Hemostasis / Q000502:physiology; D006801:Humans; D009203:Myocardial Infarction / Q000503:physiopathology; D017202:Myocardial Ischemia / Q000503:physiopathology*; D012084:Renin-Angiotensin System / Q000502:physiology; D014655:Vascular Resistance / Q000502:physiology
chemical_list: D002395:Catecholamines