title: Pulmonary Artery Acceleration Time Provides a Reliable Estimate of Invasive Pulmonary Hemodynamics in Children.
abstract: Pulmonary artery acceleration time (PAAT) is a noninvasive method to assess pulmonary hemodynamics, but it lacks validity in children. The aim of this study was to evaluate the accuracy of Doppler echocardiography-derived PAAT in predicting right heart catheterization (RHC)-derived pulmonary artery pressure (PAP), pulmonary vascular resistance (PVR), and compliance in children.
  
  
  
  Prospectively acquired and retrospectively measured Doppler echocardiography-derived PAAT and RHC-derived systolic PAP, mean PAP (mPAP), indexed PVR (PVRi), and compliance were compared using regression analysis in a derivation cohort of 75 children (median age, 5.3 years; interquartile range, 1.3-12.6 years) with wide ranges of pulmonary hemodynamics. To account for heart rate variability, PAAT was adjusted for right ventricular ejection time and corrected by the RR interval. Regression equations incorporating PAAT and PAAT/right ventricular ejection time from the derivation cohort were then evaluated for the accuracy of their predictive values for invasive pulmonary hemodynamics in a validation cohort of 50 age- and weight-matched children with elevated PAP and PVR.
  
  
  
  There were significant inverse correlations between PAAT and RHC-derived mPAP (r = -0.82) and PVRi (r = -0.78) and a direct correlation (r = 0.78) between PAAT and pulmonary compliance in the derivation cohort. For detection of pulmonary hypertension (PRVi > 3 Wood units · m2and mPAP > 25 mm Hg), PAAT < 90 msec and PAAT/right ventricular ejection time < 0.31 resulted in sensitivity of 97% and specificity of 95%. In the derivation cohort, the regression equations relating PAAT with mPAP and PVRi were mPAP = 48 - 0.28 × PAAT and PVRi = 9 - 0.07 × PAAT. These PAAT-integrated equations predicted RHC-measured pulmonary hemodynamics in the validation cohort with good correlations (r = 0.88 and r = 0.83, respectively), small biases (<10%), and minimal coefficients of variation (<8%).
  
  
  
  PAAT inversely correlates with RHC-measured pulmonary hemodynamics and directly correlates with pulmonary arterial compliance in children. The study established PAAT-based regression equations in children to accurately predict RHC-derived PAP and PVR.
authors.affiliation: Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri; Department of Pediatrics, Goryeb Children's Hospital, Atlantic Health System, Morristown, New Jersey. Electronic address: levy_p@kids.wustl.edu.
authors.forename: Philip T
authors.initials: PT
authors.lastname: Levy
authors.affiliation: Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Meghna D
authors.initials: MD
authors.lastname: Patel
authors.affiliation: Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Georgeann
authors.initials: G
authors.lastname: Groh
authors.affiliation: Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Swati
authors.initials: S
authors.lastname: Choudhry
authors.affiliation: Department of Pediatrics, Rush University Medical Center, Chicago, Illinois.
authors.forename: Joshua
authors.initials: J
authors.lastname: Murphy
authors.affiliation: Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indianapolis, Indiana.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Holland
authors.affiliation: Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
authors.forename: Aaron
authors.initials: A
authors.lastname: Hamvas
authors.affiliation: Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Grady
authors.affiliation: Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Gautam K
authors.initials: GK
authors.lastname: Singh
mesh_terms: D000054:Acceleration; D001783:Blood Flow Velocity / Q000502:physiology*; D001795:Blood Pressure Determination / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007223:Infant; D008297:Male; D011651:Pulmonary Artery / Q000000981:diagnostic imaging* / Q000502:physiology*; D011652:Pulmonary Circulation / Q000502:physiology*; D011669:Pulmonary Wedge Pressure / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014655:Vascular Resistance / Q000502:physiology
keywords: Echocardiography; Pediatrics; Pulmonary artery acceleration time; Pulmonary hypertension