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A composite autonomic index as unitary metric for heart rate variability: a proof of concept
Author(s) -
Sala Roberto,
Malacarne Mara,
Solaro Nadia,
Pagani Massimo,
Lucini Daniela
Publication year - 2017
Publication title -
european journal of clinical investigation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.164
H-Index - 107
eISSN - 1365-2362
pISSN - 0014-2972
DOI - 10.1111/eci.12730
Subject(s) - heart rate variability , cardiology , medicine , percentile , metric (unit) , mathematics , statistics , population , autonomic nervous system , confounding , radar chart , coronary artery disease , heart rate , blood pressure , operations management , environmental health , economics
Background This study addresses whether a unitary cardiac autonomic nervous system index ( ANSI ), obtained combining multiple metrics from heart rate variability ( HRV ) into a radar plot could provide an easy appreciation of autonomic performance in a clinical setting. Materials and Methods Data are standardized using percentile ranking of autonomic proxies from a relatively large reference population ( n = 1593, age 39 ± 13 years). Autonomic indices are obtained from autoregressive spectral analysis of ( ECG derived) HRV at rest and during standing up. A reduced ANSI (using RR , RR variance and rest–stand difference of LF nu) is then constructed as a radar plot, quantified according to its combined area and tested against different risk subgroups. Results With growing risk profile, there is a marked reduction of the rank value of ANSI , quantified individually by the radar plot area. The practical usefulness of the approach was tested in small groups of additional subjects putatively characterized by elevated or poor autonomic performance. Data show that elite endurance athletes are characterized by elevated values of ANSI (80·6 ± 14·9, P < 0·001) while subjects with either Type 1 or Type 2 diabetes show lower values ( DM 1 = 37·0 ± 18·9 and DM 2 = 26·8 ± 23·3, P = 0·002), and patients with coronary artery disease ( CAD ) represent a nadir (17 ± 20, P < 0·001). Conclusions This observational study shows the feasibility of testing simpler metrics of cardiac autonomic regulation based on a multivariate unitary index in a preventive setting. This simple approach might foster a wider application of HRV in the clinical arena, and permit an easier appreciation of autonomic performance.