Evaluation of Right Ventricle Function in Children With Primary Nephrotic Syndrome

BACKGROUND: We aimed to evaluate right ventricle (RV) function in children with primary nephrotic syndrome (PNS). METHODS: RV 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 t(max) and dP/d t(min), respectively) were calculated. Effective pulmonary arterial elastance was calculated as end-systolic pressure divided by stroke volume. Plasma tumor necrosis factor-alpha (TNF-alpha) and insulin-like growth factor 1 (IGF-1) were also measured. RESULTS: RV 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-alpha 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. CONCLUSION: Right ventricle function was impaired in children with PNS. The characteristics were unrelated to blood pressure and IGF-1, but may be correlated with TNF-alpha and disease duration. Further studies are needed to evaluate the etiology and clinical implications of this abnormality.