Patterns in Heart Rate Variability during Hemodialysis.

Abstract

Background: Decreased Heart Rate Variability (HRV) is a measure of poor cardiovascular health and inability of the autonomic nervous system to respond to stress. Accumulation of uremic toxins in kidney failure, volume shifts, and clearance of uremic toxins by dialysis may impact HRV. We sought to evaluate how HRV changes over the course of hemodialysis sessions, and evaluate a novel HRV sensor.

Methods: Among 22 participants treated with in-center hemodialysis, we evaluated time-domain and frequency-domain HRV metrics with a gold-standard ECG device (Schiller CARDIOVIT AT-10 Plus) and a novel fingertip sensor (EliteHRV CorSense) at five time points during 2 consecutive dialysis sessions. Changes over the session were evaluated by linear mixed models with random effect terms for participant and session. Devices were compared using correlation coefficients, Wilcoxon rank sum tests, and linear regression.

Results: There were no significant changes in HRV metrics over the dialysis session (p-value for trend across ECG 0.11, across CorSense 0.58). Time-domain HRV metrics were moderately correlated between the two methods (correlation coefficient for SDNN 0.72 and for RMSSD 0.66), while frequency-domain methods were not. Linear models comparing CorSense and ECG readings suggested strong association for time-domain metrics.

Conclusions: HRV metrics did not significantly change over the course of hemodialysis sessions, suggesting poor autonomic function during dialysis. A novel fingertip sensor accurately measured time-domain (but not frequency-domain) HRV metrics when compared to a gold-standard ECG device.