AUTHOR=Zhang Yanru , de Peuter Olav R., Kamphuisen Pieter W., Karemaker John M.

TITLE=Search for HRV-parameters that detect a sympathetic shift in heart failure patients on β-blocker treatment

JOURNAL=Frontiers in Physiology

VOLUME=4

YEAR=2013

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2013.00081

DOI=10.3389/fphys.2013.00081

ISSN=1664-042X

ABSTRACT=<p><bold>Background</bold>: A sympathetic shift in heart rate variability (HRV) from high to lower frequencies may be an early signal of deterioration in a monitored patient. Most chronic heart failure (CHF) patients receive β-blockers. This tends to obscure HRV observation by increasing the fast variations. We tested which HRV parameters would still detect the change into a sympathetic state.</p><p><bold>Methods and results</bold>: β-blocker (Carvedilol®) treated CHF patients underwent a protocol of 10 min supine rest, followed by 10 min active standing. CHF patients (NYHA Class II–IV) <italic>n</italic> = 15, 10m/5f, mean age 58.4 years (47–72); healthy controls <italic>n</italic> = 29, 18m/11f, mean age 62.9 years (49–78). Interbeat intervals (IBI) were extracted from the finger blood pressure wave (Nexfin®). Both linear and non-linear HRV analyses were applied that (1) might be able to differentiate patients from healthy controls under resting conditions and (2) detect the change into a sympathetic state in the present short recordings.</p><p><bold>Linear</bold>: mean-IBI, SD-IBI, root mean square of successive differences (rMSSD), pIBI-50 (the proportion of intervals that differs by more than 50 ms from the previous), LF, HF, and LF/HF ratio.</p><p><bold>Non-linear</bold>: Sample entropy (SampEn), Multiscale entropy (MSE), and derived: Multiscale variance (MSV) and Multiscale rMSSD (MSD). In the supine resting situation patients differed from controls by having higher HF and, consequently, lower LF/HF. In addition their longer range (τ = 6–10) MSE was lower as well. The sympathetic shift was, in controls, detected by mean-IBI, rMSSD, pIBI-50, and LF/HF, all going down; in CHF by mean-IBI, rMSSD, pIBI-50, and MSD (τ = 6–10) going down. MSD6–10 introduced here works as a band-pass filter favoring frequencies from 0.02 to 0.1 Hz.</p><p><bold>Conclusions</bold>: In β-blocker treated CHF patients, traditional time domain analysis (mean-IBI, rMSSD, pIBI-50) and MSD6–10 provide the most useful information to detect a condition change.</p>