title: Echocardiographic assessment of interventricular and intraventricular mechanical synchrony in normal dogs.
abstract: OBJECTIVE
  The aims of this prospective study are to (1) generate normal ranges for interventricular and intraventricular mechanical synchrony in dogs, and (2) generate normal ranges for tissue Doppler imaging (TDI) velocity imaging and speckle tracking strain imaging assessment of segmental intraventricular mechanical synchrony in dogs.
  
  
  METHODS
  10 prospectively recruited healthy dogs.
  
  
  METHODS
  Dogs were excluded if they had abnormal historical, physical examination, echocardiographic, ECG or systolic blood pressure findings. Interventricular mechanical synchrony was assessed using time difference between left and right ventricular pre-ejection periods. Intraventricular mechanical synchrony was assessed using both M-mode and color M-mode septal to posterior wall mechanical delay (SPWMD). Intraventricular segmental mechanical synchrony was assessed using both color TDI and speckle tracking strain analysis of segmental myocardial motion during systole and diastole.
  
  
  RESULTS
  All synchrony measures were found to be independent of age or body weight. Normal range for mechanical interventricular synchrony was found to be -10.2 to 12.6 ms. Assessment of mechanical intraventricular synchrony using either M-mode or color M-mode SPWMD was found to be associated with an extremely wide normal range, limiting clinical applicability. Normal ranges for segmental intraventricular mechanical synchrony assessed using either color TDI or speckle tracking were found to be comparable to those published for human subjects.
  
  
  CONCLUSIONS
  Interventricular and intraventricular mechanical synchrony in dogs is independent of age and body weight. The normal ranges identified in this study form a basis for assessment of normal versus abnormal mechanical synchrony in canine cardiovascular disease patients.
authors.affiliation: Department of Medicine and Epidemiology, College of Veterinary Medicine, University of California, Davis, CA 95616, USA. lggriffiths@ucdavis.edu
authors.forename: Leigh G
authors.initials: LG
authors.lastname: Griffiths
authors.forename: Jenna R
authors.initials: JR
authors.lastname: Fransioli
authors.forename: Munashe
authors.initials: M
authors.lastname: Chigerwe
mesh_terms: D000367:Age Factors; D000818:Animals; D001835:Body Weight; D003971:Diastole / Q000502:physiology; D004285:Dogs; D004452:Echocardiography / Q000662:veterinary; D018618:Echocardiography, Doppler, Color / Q000662:veterinary*; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D008297:Male; D011446:Prospective Studies; D012016:Reference Values; D013599:Systole / Q000502:physiology; D016276:Ventricular Function