title: Pulmonary venous flow index as a predictor of pulmonary vascular resistance variability in congenital heart disease with increased pulmonary flow: a comparative study before and after oxygen inhalation.
abstract: OBJECTIVE
  There is no definitive and reliable echocardiographic method for estimating the pulmonary vascular resistance (PVR) to differentiate persistent vascular disease from dynamic pulmonary hypertension. The aim of this study was to analyze the relationship between the pulmonary venous blood flow velocity-time integral (VTIpv) and PVR.
  
  
  RESULTS
  Eighteen patients (10 females; 4 months to 22 years of age) with congenital heart disease and left to right shunt were studied. They underwent complete cardiac catheterization, including measurements of the PVR and Qp:Qs ratio, before and after 100% oxygen inhalation. Simultaneous left inferior pulmonary venous flow VTIpv was obtained by Doppler echocardiography. The PVR decreased significantly from 5.0 ± 2.6 W to 2.8 ± 2.2 W (P = 0.0001) with a significant increase in the Qp:Qs ratio, from 3.2 ± 1.4 to 4.9 ± 2.4 (P = 0.0008), and the VTIpv increased significantly from 22.6 ± 4.7 cm to 28.1 ± 6.2 cm (P = 0.0002) after 100% oxygen inhalation. VTIpv correlated well with the PVR and Qp:Qs ratio (r = -0.74 and 0.72, respectively). Diagnostic indexes indicated a sensitivity of 86%, specificity of 75%, accuracy of 83%, a positive predictive value of 92% and a negative predictive value of 60%.
  
  
  CONCLUSIONS
  The VTIpv correlated well with the PVR. The measurement of this index before and after oxygen inhalation may become a useful noninvasive test for differentiating persistent vascular disease from dynamic and flow-related pulmonary hypertension.
authors.affiliation: Echocardiographic and Cardiovascular Imaging Laboratory, Department of Cardiology, São Paulo Hospital, Federal University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Ivan Romero
authors.initials: IR
authors.lastname: Rivera
authors.forename: Maria Alayde
authors.initials: MA
authors.lastname: Mendonça
authors.forename: José Lázaro
authors.initials: JL
authors.lastname: Andrade
authors.forename: Valdir
authors.initials: V
authors.lastname: Moises
authors.forename: Orlando
authors.initials: O
authors.lastname: Campos
authors.forename: Célia Camelo
authors.initials: CC
authors.lastname: Silva
authors.forename: Antonio Carlos
authors.initials: AC
authors.lastname: Carvalho
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D001783:Blood Flow Velocity; D002648:Child; D002675:Child, Preschool; D015150:Echocardiography, Doppler / Q000379:methods; D005260:Female; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D007223:Infant; D008297:Male; D010100:Oxygen / Q000008:administration & dosage; D011651:Pulmonary Artery / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011652:Pulmonary Circulation; D011667:Pulmonary Veins / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014655:Vascular Resistance; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Doppler; congenital heart disease; echocardiography; pulmonary hypertension; pulmonary vein; pulmonary venous flow