title: Echocardiographic estimation of right ventricular stroke work in children with pulmonary arterial hypertension: comparison with invasive measurements.
abstract: BACKGROUND
  Right ventricular (RV) failure is a key determinant of mortality in children with pulmonary arterial hypertension (PAH). RV stroke work (RVSW) can be estimated as the product of RV systolic pressure and stroke volume. The authors have shown that RVSW predicts adverse outcomes in this population when derived from hemodynamic data; noninvasive assessment of RVSW may be advantageous but has not been assessed. There are few data validating noninvasive versus invasive measurements in children with PAH. The aim of this study was to compare echocardiographically derived RVSW with RVSW determined from hemodynamic data.
  
  
  METHODS
  This was a retrospective study, including subjects with idiopathic PAH and minor or repaired congenital heart disease. Forty-nine subjects were included, in whom cardiac catheterization and echocardiography were performed within 1 month. Fourteen additional patients were included in a separate cohort, in whom catheterization and echocardiography were performed simultaneously. Catheterization-derived RVSW was calculated as RV systolic pressure × (cardiac output/heart rate). Echocardiographically derived RVSW was calculated as 4 × (peak tricuspid regurgitant jet velocity)(2) × (pulmonary valve area × velocity-time integral). Statistics included the intraclass correlation coefficient and Bland-Altman analysis.
  
  
  RESULTS
  Echocardiographically derived RVSW was linearly correlated with invasively derived RVSW (r = 0.74, P < .0001, intraclass correlation coefficient = 0.76). Bland-Altman analysis showed adequate agreement. Echocardiographically derived RV work was related to indexed pulmonary vascular resistance (r = 0.43, P = .002), tricuspid annular plane systolic excursion (r = 0.41, P = .004), and RV wall thickness (r = 0.62, P < .0001).
  
  
  CONCLUSIONS
  The authors demonstrate that RV work, a potential novel index of RV function, can be estimated noninvasively and is related to pulmonary hemodynamics and other indices of RV performance.
authors: The Heart Institute, Children's Hospital Colorado, University of Colorado at Denver Anschutz Medical Campus, Aurora, Colorado. Electronic address: michael.dimaria@childrenscolorado.org.
authors: Michael V
authors: MV
authors: Di Maria
authors: The Heart Institute, Children's Hospital Colorado, University of Colorado at Denver Anschutz Medical Campus, Aurora, Colorado.
authors: Dale A
authors: DA
authors: Burkett
authors: The Heart Institute, Children's Hospital Colorado, University of Colorado at Denver Anschutz Medical Campus, Aurora, Colorado.
authors: Adel K
authors: AK
authors: Younoszai
authors: The Heart Institute, Children's Hospital Colorado, University of Colorado at Denver Anschutz Medical Campus, Aurora, Colorado.
authors: Bruce F
authors: BF
authors: Landeck
authors: Division of Cardiology, The Labatt Family Heart Center, Hospital for Sick Children and University of Toronto, Toronto, Ontario, Canada.
authors: Luc
authors: L
authors: Mertens
authors: The Heart Institute, Children's Hospital Colorado, University of Colorado at Denver Anschutz Medical Campus, Aurora, Colorado.
authors: D Dunbar
authors: DD
authors: Ivy
authors: Division of Cardiology, The Labatt Family Heart Center, Hospital for Sick Children and University of Toronto, Toronto, Ontario, Canada.
authors: Mark K
authors: MK
authors: Friedberg
authors: Department of Bioengineering, University of Colorado at Denver Anschutz Medical Campus, Aurora, Colorado.
authors: Kendall S
authors: KS
authors: Hunter
mesh_terms: D000293:Adolescent; D006328:Cardiac Catheterization / Q000379:methods; D002648:Child; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000503:physiopathology
keywords: Pulmonary hypertension; Right ventricular function; Stroke work