Discriminating between two autonomic profiles related to posture in Olympic athletes

Abstract

In world class Olympic athletes we have shown that a small subset of RR variability indices, related to sympathovagal balance, may be more appropriate than RR variance to assess excitatory sympathetic autonomic responsiveness of the SA node. These findings may have practical implications for the use of RR variability in guiding training and predicting success in competitions.

A composite autonomic index as unitary metric for heart rate variability: a proof of concept

“…We approach this issue with factor analysis showing that the large majority of information embedded into HRV is carried by only three separate factors: normalized oscillatory indices, absolute indices and RR (the inverse of HR). These findings are in agreement with previous studies, showing that amplitude and oscillations convey the bulk of information on autonomic cardiac regulation, and that few indices are sufficient to predict the horizontal from the upright position [24], or the hypertensive from normotensive state [13]. Furthermore, the strong correlation between ANSI obtained with three or eight proxies supports the parsimony criterion of using for the last part of analysis the simpler ANSI 3 .…”

“…This approach may foster clinical applications. reliable information on ANS function at baseline, while others are more useful during induced or spontaneous sympathetic predominance [24]. For a correct clinical interpretation, it is important to consider several interacting factors: the analysis algorithm (e.g.…”

“…For a correct clinical interpretation, it is important to consider several interacting factors: the analysis algorithm (e.g. This index might however be less reliable in detecting responses to excitatory stimuli [24]. ), the subject's or patient's clinical characteristics (health, disease, drug treatment, etc.…”

“…1). The minimum number of proxies are selected from among the HRV variables recognized as substantial by the combination of factor analysis [24], which is carried out with the principal factor extraction method and varimax rotation (considering meaningful only loadings > 0Á4), and physiological underpinnings. Reduced ANSI will be regarded as a good synthesis of autonomic information comparable to ANSI 8 if the linear correlation coefficient between the two indices is significant and high (i.e.…”

“…), the subject's or patient's clinical characteristics (health, disease, drug treatment, etc.). Moreover, some HRV variables may give more reliable information on ANS function at baseline, while others are more useful during induced or spontaneous sympathetic predominance [24]. Time domain indices like total variance, are accepted as possible markers of increasing vagal modulation of moderate aerobic training [26].…”