Usefulness of the right ventricular systolic to diastolic duration ratio to predict functional capacity and survival in children with pulmonary arterial hypertension

Am J Cardiol. 2010 Aug 1;106(3):430-6. doi: 10.1016/j.amjcard.2010.03.048. Epub 2010 Jun 18.


The objective of this study was to investigate the systolic to diastolic duration ratio (S:D ratio) in children with pulmonary arterial hypertension (PAH) and its association with right ventricular (RV) performance, hemodynamics, 6-minute walk test, clinical outcomes, and survival. We reviewed 503 serial echocardiograms in 47 children with PAH (mean pulmonary artery pressure >or=25 mm Hg) and compared the S:D ratio, assessed from Doppler flow of tricuspid valve regurgitation, to that in 47 age-matched controls. We reviewed echocardiograms, catheterization data, 6-minute walk tests, clinical data, lung transplantation, and death and used univariate linear regression models with a maximum likelihood algorithm for parameter estimation to investigate associations between S:D ratio and RV function, hemodynamics, functional capacity, and clinical outcomes. The S:D ratio was significantly higher in patients than in controls (1.38 +/- 0.61 vs 0.72 +/- 0.16, p <0.001). A higher S:D ratio was associated with worse echocardiographic RV fractional area of change, worse catheterization hemodynamics, shorter 6-minute walk distance, and worse clinical outcomes independent of pulmonary resistance or pressures. An increase of 0.1 in the S:D ratio was associated with a 13% increase in yearly risk for lung transplantation or death (hazard ratio 1.13, p <0.001). An S:D ratio 1.00 to 1.40 was associated with a moderate risk and an S:D ratio >1.40 was associated with a high risk of a negative outcome. In conclusion, in children with PAH, an increased S:D ratio is temporally associated with worse RV function, hemodynamics, exercise capability, clinical status, and survival.

MeSH terms

  • Adolescent
  • Case-Control Studies
  • Child
  • Child, Preschool
  • Diastole
  • Echocardiography, Doppler
  • Exercise Test
  • Female
  • Hemodynamics
  • Humans
  • Hypertension, Pulmonary / diagnostic imaging
  • Hypertension, Pulmonary / physiopathology*
  • Infant
  • Infant, Newborn
  • Linear Models
  • Male
  • Predictive Value of Tests
  • Respiratory Function Tests
  • Survival Analysis
  • Systole
  • Ventricular Dysfunction, Right / diagnostic imaging
  • Ventricular Dysfunction, Right / physiopathology
  • Young Adult