Evaluation of Right Ventricle Function in Children With Primary Nephrotic Syndrome

BackgroundWe aimed to evaluate right ventricle (RV) function in children with primary nephrotic syndrome (PNS).MethodsRV hemodynamics were evaluated by Doppler echocardiography in 50 children with PNS (aged 2.5–12 years), either at PNS onset (n = 37) or relapse (n = 13), and in 50 normal controls. Heart rate, stroke volume, cardiac output, RV enddiastolic and end-systolic volume, RV ejection fraction, RV end-diastolic pressure, RV peak systolic and end-systolic pressure were determined from pressure-volume loops. The maximal rates of RV pressure upstroke and fall (dP/d tmax and dP/d tmin, respectively) were calculated. Effective pulmonary arterial elastance was calculated as end-systolic pressure divided by stroke volume. Plasma tumor necrosis factor-α (TNF-α) and insulin-like growth factor 1 (IGF-1) were also measured.ResultsRV end-diastolic pressure was increased by an average of 20% in 39 of the patients with PNS, whereas RV ejection fraction was reduced by an average of 15% compared with controls (p < 0.05 for both). Cardiac output and stroke volume were maintained, indicating compensation at the expense of increased RV end-diastolic and end-systolic volumes and increased RV filling pressure (p < 0.05). Plasma TNF-α was elevated in patients with PNS (326 ± 117 kU/L vs. 75 ± 23 kU/L, p < 0.05); IGF-1 was similar in PNS patients and controls.ConclusionRight ventricle function was impaired in children with PNS. The characteristics were unrelated to blood pressure and IGF-1, but may be correlated with TNF-α and disease duration. Further studies are needed to evaluate the etiology and clinical implications of this abnormality.