title: Effects of age, body weight, and heart rate on transmitral and pulmonary venous flow in clinically normal dogs.
abstract: OBJECTIVE
  To determine the influence of age, body weight (BW), heart rate (HR), sex, and left ventricular shortening fraction (LVSF) on transmitral and pulmonary venous flow in clinically normal dogs.
  
  
  METHODS
  92 client-owned dogs 3 months to 19 years old.
  
  
  METHODS
  Transthoracic Doppler echocardiography recordings of transmitral flow and pulmonary venous flow were obtained in conscious unsedated dogs. Influence of age, BW, HR, sex, and LVSF on diastolic variables was assessed, using statistical methods such as ANOVA on ranks and univariate and multivariate forward stepwise linear regression analyses.
  
  
  RESULTS
  Age significantly influenced isovolumic relaxation time (IVRT, r = 0.56), ratio between peak velocity of the early diastolic mitral flow wave-to-peak velocity of late diastolic mitral flow wave (E:A; r = -0.44), deceleration time of early diastolic mitral flow (DTE; r = 0.26), and peak velocity of atrial reversal pulmonary venous flow wave (AR-wave; r = 0.37). Significant changes of mitral inflow and pulmonary venous flow variables were evident only in dogs > 6 and > 10 years old, respectively. Body weight significantly influenced DTE (r = 0.63), late diastolic flow duration (r = 0.60), and AR duration (r = 0.47), whereas HR significantly affected DTE (r = -0.34), IVRT (r = -0.33), and peak velocity of AR (r = 0.24). Sex or LVSF (range 22 to 48%) did not influence any echocardiographic variables.
  
  
  CONCLUSIONS
  Age, BW, and HR are important factors that affect filling of the left atrium and left ventricle in clinically normal dogs.
authors.affiliation: Department of Small Animals, Faculty of Veterinary Medicine, University of Leipzig, Germany.
authors.forename: K E
authors.initials: KE
authors.lastname: Schober
authors.forename: V L
authors.initials: VL
authors.lastname: Fuentes
mesh_terms: D000367:Age Factors; D000818:Animals; D016279:Atrial Function, Left / Q000502:physiology; D001783:Blood Flow Velocity / Q000502:physiology / Q000662:veterinary; D001835:Body Weight / Q000502:physiology; D004285:Dogs / Q000502:physiology*; D018618:Echocardiography, Doppler, Color / Q000662:veterinary; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D016014:Linear Models; D008297:Male; D008943:Mitral Valve / Q000502:physiology*; D015999:Multivariate Analysis; D011667:Pulmonary Veins / Q000502:physiology*; D012016:Reference Values; D016277:Ventricular Function, Left / Q000502:physiology*