The association between systolic and diastolic dysfunction and autonomic nervous system function in children receiving chronic hemodialysis.

Background: Changes in cardiac function and structure as well as their association with the cardiac autonomic nervous system remain incompletely characterized in children with stage 5 chronic kidney disease (CKD) receiving hemodialysis (HD).

Methods: A prospective observational cohort study was conducted on 40 Egyptian children with CKD on regular HD compared to 40 age- and sex-matched healthy children. All participants underwent thorough clinical examination, laboratory investigations, 24-h Holter monitoring, and 2D/4D echocardiographic study (conventional and advanced modalities). Participants were followed for mortality and morbidity over 36 months.

Results: Following HD sessions, CKD children showed significant reductions of left and right ventricular (LV/RV) systolic function by 2D and 4D echocardiography compared to controls. HD children had significant impairment of heart rate variability parameters (evaluated by time and frequency domains). LV/RV global longitudinal shortening (GLS) as well as tricuspid annular plane systolic excursion were closely correlated with different Holter parameters, including frequency domain parameters (including low frequency, high frequency, and LF/HF ratio), time domain parameters including percentage of differences > 50 ms between consecutive normal RR intervals (pNN50), and root-mean-square of the difference between successive normal intervals (rMSSD). Over a follow-up of 34.5 ± 16.8 months, 10 (25%) patients died. Reduced LV/RV-GLS and decreased rMSSD values were independently associated with higher mortality among HD children.

Conclusions: LV and RV myocardial deformation (either 2D or 4D) primarily decreased in HD children. Altered time and frequency domain indices revealed cardiac autonomic dysfunction, evidenced by increased sympathetic activity and decreased vagal activity. Reduced LV/RV-GLS and decreased rMSSD values were independently associated with higher mortality among HD children.