title: Noninvasive assessment of pulmonary arterial capacitance by echocardiography.
abstract: BACKGROUND
  Pulmonary arterial capacitance (PAC) has been associated with right ventricular (RV) workload and mortality in pulmonary hypertension, but is not routinely evaluated in children. We investigated whether PAC can be estimated noninvasively by echocardiography.
  
  
  METHODS
  We retrospectively determined PAC in 31 children with pulmonary hypertension, using echocardiography, and compared the results with those obtained at cardiac catheterization.
  
  
  RESULTS
  PAC derived from echocardiography was similar to that derived from catheterization (mean +/- SD 1.16 +/- 1.0 vs 1.10 +/- 0.95 mL(3) x mm Hg(-1), P = not significant) and the two correlated well (r = 0.74, P < .0001). There was a highly significant polynomial relationship between PAC and RV anterior wall thickness indexed to body surface area (R(2) = 0.54, P < .0001), but not between pulmonary vascular resistance and RV wall thickness. Pulmonary vascular resistance and PAC did not correlate.
  
  
  CONCLUSIONS
  Echocardiography can reliably estimate PAC, which strongly correlates with RV hypertrophy, a surrogate for RV work.
authors.affiliation: Division of Pediatric Cardiology, Stanford University, Stanford, California, USA.
authors.forename: Mark K
authors.initials: MK
authors.lastname: Friedberg
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Feinstein
authors.forename: David N
authors.initials: DN
authors.lastname: Rosenthal
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography / Q000379:methods; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D017380:Hypertrophy, Right Ventricular / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011651:Pulmonary Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018924:Vascular Capacitance