title: Normal Reference Values and z Scores of the Pulmonary Artery Acceleration Time in Children and Its Importance for the Assessment of Pulmonary Hypertension.
abstract: BACKGROUND
  Pulsed-wave Doppler determination of the pulmonary artery acceleration time (PAAT) as a surrogate for pulmonary artery pressure was found to be of clinical value for assessment of pulmonary hypertension (PH) with studies to date exclusively performed in adults. This study aims to provide representative, normal reference values for PAAT in children of all ages. Moreover, we validated abnormal PAAT values in 54 children with PH.
  
  
  RESULTS
  We conducted a prospective echocardiographic study in 756 healthy children (aged 1 day to 18 years) and in 54 children with PH. Possible associations of age, body length, body weight, body surface area, and heart rate on PAAT were investigated. The PAAT correlated positively with age (r=0.848), body length (r=0.871), body surface area (r=0.856), and body weight (r=0.825) and negatively with heart rate (r=-0.906). PAAT increased with age (neonates: median: 81 ms, range: 53-104; 18th year of life: median: 151 ms, range: 107-187). Receiver operating characteristic analysis for detecting PH patients using age-specific z scores showed an excellent performance of PAAT (P<0.001; area under the curve, 0.98; 95% confidence interval, 0.97-0.99) with a best cutoff score according to Youden index of -1.565 (sensitivity: 92%, specificity: 96%). PAAT values of PH patients negatively correlated (ρ=-0.497) with pulmonary vascular resistance.
  
  
  CONCLUSIONS
  The PAAT normal reference values and z scores we provide here will be useful to identify children with a shortened PAAT. Abnormal PAAT values with scores <-2 were predictive of PH.
authors.affiliation: From the Division of Pediatric Cardiology, Department of Pediatrics (M.K., G.G., A.G., M.G., A.B.), Institute for Medical Informatics, Statistics and Documentation (A.A.), and Centre of Physiological Medicine (G.C.), Medical University Graz, Austria; and Department of Pediatric Cardiology and Critical Care, Hannover Medical School, Hannover, Germany (G.H.). martin.koestenberger@medunigraz.at koestenbergerm@gmx.at.
authors.forename: Martin
authors.initials: M
authors.lastname: Koestenberger
authors.affiliation: From the Division of Pediatric Cardiology, Department of Pediatrics (M.K., G.G., A.G., M.G., A.B.), Institute for Medical Informatics, Statistics and Documentation (A.A.), and Centre of Physiological Medicine (G.C.), Medical University Graz, Austria; and Department of Pediatric Cardiology and Critical Care, Hannover Medical School, Hannover, Germany (G.H.).
authors.forename: Gernot
authors.initials: G
authors.lastname: Grangl
authors.affiliation: From the Division of Pediatric Cardiology, Department of Pediatrics (M.K., G.G., A.G., M.G., A.B.), Institute for Medical Informatics, Statistics and Documentation (A.A.), and Centre of Physiological Medicine (G.C.), Medical University Graz, Austria; and Department of Pediatric Cardiology and Critical Care, Hannover Medical School, Hannover, Germany (G.H.).
authors.forename: Alexander
authors.initials: A
authors.lastname: Avian
authors.affiliation: From the Division of Pediatric Cardiology, Department of Pediatrics (M.K., G.G., A.G., M.G., A.B.), Institute for Medical Informatics, Statistics and Documentation (A.A.), and Centre of Physiological Medicine (G.C.), Medical University Graz, Austria; and Department of Pediatric Cardiology and Critical Care, Hannover Medical School, Hannover, Germany (G.H.).
authors.forename: Andreas
authors.initials: A
authors.lastname: Gamillscheg
authors.affiliation: From the Division of Pediatric Cardiology, Department of Pediatrics (M.K., G.G., A.G., M.G., A.B.), Institute for Medical Informatics, Statistics and Documentation (A.A.), and Centre of Physiological Medicine (G.C.), Medical University Graz, Austria; and Department of Pediatric Cardiology and Critical Care, Hannover Medical School, Hannover, Germany (G.H.).
authors.forename: Marlene
authors.initials: M
authors.lastname: Grillitsch
authors.affiliation: From the Division of Pediatric Cardiology, Department of Pediatrics (M.K., G.G., A.G., M.G., A.B.), Institute for Medical Informatics, Statistics and Documentation (A.A.), and Centre of Physiological Medicine (G.C.), Medical University Graz, Austria; and Department of Pediatric Cardiology and Critical Care, Hannover Medical School, Hannover, Germany (G.H.).
authors.forename: Gerhard
authors.initials: G
authors.lastname: Cvirn
authors.affiliation: From the Division of Pediatric Cardiology, Department of Pediatrics (M.K., G.G., A.G., M.G., A.B.), Institute for Medical Informatics, Statistics and Documentation (A.A.), and Centre of Physiological Medicine (G.C.), Medical University Graz, Austria; and Department of Pediatric Cardiology and Critical Care, Hannover Medical School, Hannover, Germany (G.H.).
authors.forename: Ante
authors.initials: A
authors.lastname: Burmas
authors.affiliation: From the Division of Pediatric Cardiology, Department of Pediatrics (M.K., G.G., A.G., M.G., A.B.), Institute for Medical Informatics, Statistics and Documentation (A.A.), and Centre of Physiological Medicine (G.C.), Medical University Graz, Austria; and Department of Pediatric Cardiology and Critical Care, Hannover Medical School, Hannover, Germany (G.H.).
authors.forename: Georg
authors.initials: G
authors.lastname: Hansmann
mesh_terms: D000054:Acceleration; D000293:Adolescent; D019540:Area Under Curve; D062186:Arterial Pressure; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D018619:Echocardiography, Doppler, Pulsed / Q000379:methods*; D005260:Female; D006339:Heart Rate; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging* / Q000503:physiopathology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012372:ROC Curve; D012016:Reference Values; D013997:Time Factors
keywords: body surface area; body weight; child; echocardiography; heart rate