title: Circadian pattern of symptoms onset in patients ≤35 years presenting with ST-segment elevation acute myocardial infarction.
abstract: BACKGROUND
  There are scarce data regarding the circadian pattern of symptoms onset in young patients presenting with acute myocardial infarction (AMI). We explored whether young patients with ST-segment elevation AMI exhibit a circadian variation in symptoms onset.
  
  
  METHODS
  We recruited prospectively 256 consecutive patients who had survived their first ST-segment elevation AMI ≤35 years of age. Patients were categorized into 4 groups by 6-h intervals over 24 h.
  
  
  RESULTS
  In 49 patients (19.1%) the clinical presentation of AMI was atypical. The symptoms onset was as follows: 00:01 to 06:00, 19.1%, 06:01 to 12:00, 32.4%; 12:01 to 18:00, 28.1%; and 18:01 to 24:00, 20.3%. There was a significant association between the time of day and the likelihood of symptoms onset (Rayleigh test, p<0.001). Between 00:01 and 06:00 the incidence of AMI onset was lower than expected and between 06:01 and 12:00 was higher (p=0.034 and p=0.011, respectively), whereas in the other 6-h period groups no difference was found between expected and observed AMI incidence (p=0.280 and p=0.131). No significant differences were found regarding clinical characteristics, i.e. traditional risk factors, reperfusion treatment of AMI, ejection fraction of left ventricle, time interval from pain onset to hospital arrival, dietary habits and physical activity, among the 6-h period groups.
  
  
  CONCLUSIONS
  ST-segment elevation AMI in individuals ≤35 years of age follows a circadian pattern with a morning peak. This information might be useful for the prompt diagnosis and treatment of AMI in very young patients which occurs rarely and frequently with atypical clinical presentation.
authors.affiliation: Second Department of Cardiology, University General Hospital Attikon, Athens, Greece. Electronic address: rallidis@ath.forthnet.gr.
authors.forename: Loukianos S
authors.initials: LS
authors.lastname: Rallidis
authors.affiliation: Second Department of Cardiology, University General Hospital Attikon, Athens, Greece.
authors.forename: Andreas S
authors.initials: AS
authors.lastname: Triantafyllis
authors.affiliation: Second Department of Cardiology, University General Hospital Attikon, Athens, Greece.
authors.forename: Eleftherios A
authors.initials: EA
authors.lastname: Sakadakis
authors.affiliation: Laboratory of Haematology and Blood Transfusion Unit, University General Hospital Attikon, Athens, Greece.
authors.forename: Argyri
authors.initials: A
authors.lastname: Gialeraki
authors.affiliation: Second Department of Cardiology, University General Hospital Attikon, Athens, Greece.
authors.forename: Christos
authors.initials: C
authors.lastname: Varounis
authors.affiliation: Department of Nutrition and Dietetics, Harokopio University, Athens, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Rallidi
authors.affiliation: Second Department of Cardiology, University General Hospital Attikon, Athens, Greece.
authors.forename: Georgios
authors.initials: G
authors.lastname: Tsirebolos
authors.affiliation: Biochemistry Laboratory, General Hospital of Nikea, Piraeus, Greece.
authors.forename: Georgios
authors.initials: G
authors.lastname: Liakos
authors.affiliation: Second Department of Cardiology, University General Hospital Attikon, Athens, Greece.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Dagres
authors.affiliation: Second Department of Cardiology, University General Hospital Attikon, Athens, Greece.
authors.forename: Jonh
authors.initials: J
authors.lastname: Lekakis
mesh_terms: D000328:Adult; D000367:Age Factors; D002637:Chest Pain / Q000209:etiology; D002940:Circadian Rhythm / Q000502:physiology*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000175:diagnosis / Q000503:physiopathology*; D011446:Prospective Studies; D013997:Time Factors
keywords: Circadian variation; Premature myocardial infarction; Smoking