Abstract: Background: Autonomic dysfunction as a long-term complication may occur in end-stage

kidney disease (ESKD) patients and can be diagnosed using heart rate variability (HRV) analyzed

from electrocardiogram (ECG) recordings. There is limited data about HRV using real-time ECG

to predict hemodialysis (HD) efficiency in patients with ESKD who are routinely doing HD in the

real world. Methods: A total of 50 patients (62.1 ± 10.7 years) with ESKD underwent continuous

real-time ECG monitoring (237.4 ± 15.3 min) during HD for HRV using remote monitoring system.

Their electrolyte levels were checked before and after HD.We compared HRV according to electrolyte

levels. Results: During the monitor, we checked the ECG and electrolyte levels simultaneously a

total of 2374 times for all of the patients. Both time and frequency domain HRV were higher when

the patients had lower K+ level (<0.5 mEq/L) and P+ level change (<2 mEq/L) before and after

HD as compared to those with a higher K+ level (≥0.5 mEq/L) and P+ level change (≥2 mEq/L).

Additionally, patients with lower K+ and P+ level change groups had higher incidences of arrhythmic

events including atrial/ventricular premature complexes, despite no difference of mean heart rate

(p < 0.001). Conclusions: Higher HRV was independently associated with a poorly controlled K+

and P+ level during HD in patients with ESKD. This is consistently evidenced by the independent

association between higher HRV, K+ and P+ levels in real time, suggesting that low electrolyte changes

before and after HD alone may cause cardiac autonomic dysfunction.