title: Diagnostic Value of Right Pulmonary Artery Distensibility Index in Dogs with Pulmonary Hypertension: Comparison with Doppler Echocardiographic Estimates of Pulmonary Arterial Pressure.
abstract: BACKGROUND
  Noninvasive diagnosis of pulmonary hypertension (PH) primarily relies upon Doppler echocardiography of tricuspid regurgitation (TR). However, TR might be absent or difficult to measure.
  
  
  OBJECTIVE
  To determine the diagnostic value of right pulmonary artery distensibility (RPAD) index for prediction of Doppler-derived estimates of pulmonary artery (PA) pressure compared to other indices of PH in dogs.
  
  
  METHODS
  Sixty-nine client-owned dogs with TR.
  
  
  METHODS
  Prospective observational study. Dogs were allocated to groups according to TR pressure gradient (TRPG): TRPG <36 mmHg (control, n = 22), TRPG 36-50 (n = 16), TRPG 50-75 (n = 14) and TRPG >75 mmHg (n = 17). Right pulmonary artery distensibility index, acceleration time to peak PA flow (AT), AT: ejection time of PA flow (AT:ET) and main PA size: aorta size (MPA:Ao) were calculated in each dog.
  
  
  RESULTS
  Right pulmonary artery distensibility index demonstrated the strongest correlation (r = -0.90; P < .0001) to TRPG followed by MPA:Ao (r = 0.78; P < .0001), AT (r = -0.69; P < .0001) and AT:ET (r = -0.68; P < .0001). RPAD index possessed the most accurate cutoff (<29.5%; Sensitivity [Sn] 0.84, Specificity [Sp] 0.95) to predict TRPG >50 mmHg compared to AT (<53.9 ms; Sn 0.74, Sp 0.87), AT:ET (<0.30; Sn 0.61, Sp 0.97) and MPA:Ao (>1.04; Sn 0.94, Sp 0.74). All intra- and interobserver measurement variabilities exhibited coefficients of variation ≤13%.
  
  
  CONCLUSIONS
  Right pulmonary artery distensibility index is an accurate predictor of TRPG and should be particularly useful if TR is absent or difficult to measure.
authors.affiliation: Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, CA.
authors.forename: L C
authors.initials: LC
authors.lastname: Visser
authors.affiliation: Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, CA.
authors.forename: M K
authors.initials: MK
authors.lastname: Im
authors.affiliation: Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, CA.
authors.forename: L R
authors.initials: LR
authors.lastname: Johnson
authors.affiliation: Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, CA.
authors.forename: J A
authors.initials: JA
authors.lastname: Stern
mesh_terms: D000818:Animals; D001795:Blood Pressure Determination / Q000662:veterinary*; D004283:Dog Diseases / Q000175:diagnosis / Q000473:pathology*; D004285:Dogs; D015150:Echocardiography, Doppler / Q000662:veterinary*; D005260:Female; D006976:Hypertension, Pulmonary / Q000175:diagnosis / Q000662:veterinary*; D008297:Male; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000473:pathology*
keywords: Canine; Echocardiography; Prediction; Pulmonary vascular resistance; Right pulmonary artery distensibility