Abstract
BACKGROUND: Echocardiographic determination of RV end-systolic base/apex (RVES b/a) ratio was proposed to be of clinical value for assessment of pulmonary arterial hypertension (PAH) in adults. HYPOTHESIS: We hypothesized that the RVES b/a ratio will be affected in children with PAH and aimed to correlate RVES b/a ratio with conventionally used echocardiographic and hemodynamic variables, and with New York Heart Association (NYHA) functional class. METHODS: First we determined normal pediatric values for RVES b/a ratio in 157 healthy children (68 males; age range, 0.5-17.7 years). We then conducted an echocardiographic study in 51 children with PAH (29 males; age range, 0.3-17.8 years). RESULTS: RVES b/a ratio was lower compared with age- and sex-matched healthy controls (P < 0.001). In children with PAH, RVES b/a ratio decreased with worsening NYHA class. RVES b/a ratio inversely correlated with RV/LV end-systolic diameter ratio (ρ = -0.450, P = 0.001) but did not correlate with RV systolic function parameters (eg, tricuspid annular plane systolic excursion) and correlated with cardiac catheterization-determined pulmonary vascular resistance index (ρ = -0.571, P < 0.001). ROC analysis unraveled excellent performance of RVES b/a ratio to detect PAH in children (AUC: 0.95, 95% CI: 0.89-1.00, P < 0.001). CONCLUSIONS: The RVES b/a ratio decreased in children with PAH compared with age- and sex-matched healthy subjects. The RVES b/a ratio inversely correlated with both echocardiographic and hemodynamic indicators of increased RV pressure afterload and with NYHA class, suggesting that RVES b/a ratio reflects disease severity in PAH children.