Heart rate variability according to electrolyte changes during hemodialysis in patients with chronic kidney disease

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Autonomic neuropathy commonly arises as a long-term complication in chronic kidney disease (CKD) and can be diagnosed from heart rate variability (HRV), calculated from electrocardiogram (ECG) recordings. PURPOSE: There is limited data about HRV using real-time ECG according to electrolyte levels during hemodialysis (HD) in patients with CKD. METHODS: Total of 50 patients (62.1±10.7 years) with CKD underwent continuous real-time ECG monitor (237.4±15.3 mins) during HD for HRV using remote monitoring system and checked electrolyte levels before/after HD. And we compared HRV according to electrolyte levels. RESULTS: During the monitor, we checked total 2374 times of ECG and electrolyte level simultaneously of all patients. Both time and frequency domain HRV were higher when the patients had lower K+ level change before/after HD (<0.5mEq/L) as compared with those with higher K+ level change (>0.5mEq/L) in Table. In addition, there were higher incidence of arrhythmic events including atrial/ventricular premature complexes, even though no difference of mean heart rate in patients with lower K+ level change group (P<0.001). CONCLUSIONS: Poor controlled K+ level during hemodialysis was independently associated with higher HRV in patients with CKD. This is further substantiated by independent continuous associations between real-time measures of K+ level and higher HRV. These data strongly suggest that cardiac autonomic dysfunction can be caused by lower change before/after hemodialysis alone. [Figure: see text]