BackgroundCardiac mortality and morbidity remain signi cant in children on chronic hemodialysis (HD). Multiple markers by speckle tracking echocardiography (STE) are predictive of cardiac events in adults, but data in children are limited; ventricular diastolic strain (Ds) and left atrial strain (LAS) have not been reported.The aim of this study was to investigate intradialytic changes in ventricular and atrial function using STE in children. MethodsSecondary analysis of a prospective descriptive study of children with structurally normal hearts and HD vintage > 3 months, using echocardiography performed prior to, during, and after HD. STE was analyzed using GE EchoPAC. Left ventricular (LV) global longitudinal strain (GLS), strain rate (Sr), and mechanical dispersion index (MDI) were calculated as the average from 3 apical views; Ds and Sr were obtained from 4-chamber tracing; LAS and Sr were assessed during atrial contraction, reservoir, and conduit. Intradialytic changes in 2D STE markers of ventricular function and LAS and their association with blood volume (BV) removal and blood pressure (BP) change were studied. ResultsA total of 15 children were enrolled at a median age of 12 years (IQR 8, 16) and median HD vintage of 13 months (IQR 9, 25). GLS was impaired during HD (-15.8 ± 2.2% vs -19.9 ± 1.9%, p < 0.001). Post-HD GLS was associated mean BP decrease (coe cient = 0.62, p = 0.01) and not with BV removal (coe cient = 0.49, p = 0.06). LV MDI and systolic Sr did not change. LV Ds was progressively impaired (-8.4% (-9.2, -8.0) vs − 11.9% (-13.4, -10.3), p < 0.001). LAS conduit and reservoir worsened at mid-HD and returned to baseline post-HD. Changes in Ds, DSr, LAS, LASr were not associated with BV removal or BP decrease (p > 0.1). ConclusionsIntradialytic LV strain and LAS impairment consistent with subclinical systolic and diastolic dysfunction were observed during HD in children. GLS impairment was associated with BP change, but changes in Ds, DSr, LAS, and LASr were not associated with BP change or BV removal. Longitudinal assessment using these novel non-invasive indices may unfold the effect of cumulative subclinical changes on long-term outcomes in children who are on chronic HD.

Background Cerebral and myocardial hypoperfusion occur during hemodialysis in adults. Pediatric patients receiving chronic hemodialysis have fewer cardiovascular risk factors, yet cardiovascular morbidity remains prominent. Methods We conducted a prospective observational study of pediatric patients receiving chronic hemodialysis to investigate whether intermittent hemodialysis is associated with adverse end organ effects in the heart or with cerebral oxygenation (regional O2 saturation [rSO2]). We assessed intradialytic cardiovascular function and rSO2, using noninvasive echocardiography to determine myocardial strain and continuous noninvasive nearinfrared spectroscopy for rSO2. We measured changes in blood volume and central venous oxygen saturation (mCVO2) were pre-, mid-, and post-hemodialysis. Results The study included 15 patients (median age, 12 years; median hemodialysis vintage 13.2 [9, 24] months were included. Patients were asymptomatic. The rSO2 did not change during hemodialysis, whereas mCVO2 decreased significantly, from 73% to 64.8 %. Global longitudinal strain of the myocardium worsened significantly by mid-hemodialysis and persisted post-hemodialysis. The ejection fraction remained normal. Lower systolic blood pressure and faster blood volume change were associated with worsening myocardial strain; only blood volume change was significant in multivariate analysis (β coefficient, -0.3; 95% confidence interval [95% CI], −0.38 to −0.21; P=0.0001). Blood volume change was also associated with a significant decrease in mCVO2 (β coefficient 0.42; 95% CI, 0.07 to 0.76; P=0.001). Access, age, hemodialysis vintage, and ultrafiltration volume were not associated with worsening strain. Conclusion s Unchanged rSO2 suggested that cerebral oxygenation was maintained during hemodialysis. However, despite maintained ejection fraction, intradialytic myocardial strain worsened in pediatric hemodialysis and was associated with blood volume change. The effect of hemodialysis on individual organ perfusion in pediatric versus adult patients receiving hemodialysis might differ.