title: Time-frequency and complexity analyses for differentiation of physiologic murmurs from heart murmurs caused by aortic stenosis in Boxers.
abstract: OBJECTIVE
  To investigate whether time-frequency and complexity analyses of heart murmurs can be used to differentiate physiologic murmurs from murmurs caused by aortic stenosis (AS) in Boxers.
  
  
  METHODS
  27 Boxers with murmurs.
  
  
  METHODS
  Dogs were evaluated via auscultation and echocardiography. Analyses of time-frequency properties (TFPs; ie, maximal murmur frequency and duration of murmur frequency > 200 Hz) and correlation dimension (T(2)) of murmurs were performed on phonocardiographic sound data. Time-frequency property and T(2) analyses of low-intensity murmurs in 16 dogs without AS were performed at 7 weeks and 12 months of age. Additionally, TFP and T(2) analyses were performed on data obtained from 11 adult AS-affected dogs with murmurs.
  
  
  RESULTS
  In dogs with low-intensity murmurs, TFP or T(2) values at 7 weeks and 12 months did not differ significantly. For differentiation of physiologic murmurs from murmurs caused by mild AS, duration of murmur frequency > 200 Hz was useful and the combination assessment of duration of frequency > 200 Hz and T(2) of the murmur had a sensitivity of 94% and a specificity of 82%. Maximal murmur frequency did not differentiate dogs with AS from those without AS.
  
  
  CONCLUSIONS
  Results suggested that assessment of the duration of murmur frequency > 200 Hz can be used to distinguish physiologic heart murmurs from murmurs caused by mild AS in Boxers. Combination of this analysis with T(2) analysis may be a useful complementary method for diagnostic assessment of cardiovascular function in dogs.
authors.affiliation: Department of Anatomy and Physiology, Faculty of Veterinary Medicine and Animal Science, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden.
authors.forename: Katja
authors.initials: K
authors.lastname: Höglund
authors.forename: Christer H G
authors.initials: CH
authors.lastname: Ahlstrom
authors.forename: Jens
authors.initials: J
authors.lastname: Häggström
authors.forename: Per N A
authors.initials: PN
authors.lastname: Ask
authors.forename: P H Peter
authors.initials: PH
authors.lastname: Hult
authors.forename: Clarence
authors.initials: C
authors.lastname: Kvart
mesh_terms: D000818:Animals; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000662:veterinary*; D003627:Data Interpretation, Statistical; D004283:Dog Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004285:Dogs; D018618:Echocardiography, Doppler, Color / Q000662:veterinary; D005260:Female; D006326:Heart Auscultation / Q000662:veterinary; D006337:Heart Murmurs / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000662:veterinary*; D008297:Male