title: Seasonal diagnosis of echocardiographically demonstrated endocarditis.
abstract: BACKGROUND
  Many cardiac and infectious diseases have a seasonal incidence. It is not known whether similar variations exist for endocarditis.
  
  
  METHODS
  As echocardiography plays a key role in diagnosing endocarditis, patients referred for echocardiography with suspected endocarditis from 1993 through 2001 were identified. The modified Duke criteria were used in establishing endocarditis. The echocardiography date was arbitrarily used to determine season: fall/winter (October to March) and spring/summer (April to September).
  
  
  RESULTS
  For the 1,279 patients referred for echocardiography to rule out endocarditis, there was no seasonal difference between the total number of referred fall/winter and spring/summer patients (645 patients vs 634 patients, respectively). However, endocarditis was found in 41 fall/winter patients (6.4%) and 19 spring/summer patients (3.0%) patients (odds ratio, 2.20; 95% confidence interval, 1.26 to 3.83; p = 0.004). This seasonal disparity was present in 7 of the 9 years studied. No clinical factors could account for this seasonal disparity.
  
  
  CONCLUSIONS
  As with many other cardiac diseases, a significant fall/winter predominance for endocarditis was found.
authors.affiliation: Case Western Reserve University at MetroHealth Medical Center, 2500 MetroHealth Dr, Cleveland, OH 44109, USA. rfinkelhor@metrohealth.org
authors.forename: Robert S
authors.initials: RS
authors.lastname: Finkelhor
authors.forename: Grace
authors.initials: G
authors.lastname: Cater
authors.forename: Amir
authors.initials: A
authors.lastname: Qureshi
authors.forename: Douglas
authors.initials: D
authors.lastname: Einstadter
authors.forename: Michelle T
authors.initials: MT
authors.lastname: Hecker
authors.forename: Georgene
authors.initials: G
authors.lastname: Bosich
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017548:Echocardiography, Transesophageal; D004562:Electrocardiography; D004696:Endocarditis / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D005260:Female; D006351:Heart Valves / Q000000981:diagnostic imaging; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009820:Ohio / Q000453:epidemiology; D012189:Retrospective Studies; D012621:Seasons; D015819:Substance Abuse, Intravenous / Q000150:complications