Heart Rate Variability Code: Does It Exist and Can We Hack It?

Abstract

A code is generally defined as a system of signals or symbols for communication. Experimental evidence is synthesized for the presence and utility of such communication in heart rate variability (HRV) with particular attention to fetal HRV: HRV contains signatures of information flow between the organs and of response to physiological or pathophysiological stimuli as signatures of states (or syndromes). HRV exhibits features of time structure, phase space structure, specificity with respect to (organ) target and pathophysiological syndromes, and universality with respect to species independence. Together, these features form a spatiotemporal structure, a phase space, that can be conceived of as a manifold of a yet-to-be-fully understood dynamic complexity. The objective of this article is to synthesize physiological evidence supporting the existence of HRV code: hereby, the process-specific subsets of HRV measures indirectly map the phase space traversal reflecting the specific information contained in the code required for the body to regulate the physiological responses to those processes. The following physiological examples of HRV code are reviewed, which are reflected in specific changes to HRV properties across the signal–analytical domains and across physiological states and conditions: the fetal systemic inflammatory response, organ-specific inflammatory responses (brain and gut), chronic hypoxia and intrinsic (heart) HRV (iHRV), allostatic load (physiological stress due to surgery), and vagotomy (bilateral cervical denervation). Future studies are proposed to test these observations in more depth, and the author refers the interested reader to the referenced publications for a detailed study of the HRV measures involved. While being exemplified mostly in the studies of fetal HRV, the presented framework promises more specific fetal, postnatal, and adult HRV biomarkers of health and disease, which can be obtained non-invasively and continuously.

An in‐depth analysis of the polyvagal theory in light of current findings in neuroscience and clinical research

“…Finally, the HRV does not simply derive from the sympathetic or vagal activity but also the pacemaker cells of the heart and, above all, from the central autonomic network (i.e., the brain system that influences both the regulation of the internal state of the organism and the cortical functions such as cognitions, emotions, and behaviors) (Chiera et al, 2020;Frasch, 2023;Frasch et al, 2020;Herry et al, 2019).…”

“…As epigenetics, even the HRV analysis itself requires a change of perspective toward a more complex vision of the ANS developmenthence of the VN-since there is not just one parameter evaluating the HRV, but multiple domains (time, frequencies, and nonlinear), of which the RSA is only one of the possible metrics that can be used allowing us to capture different nuances of the development of the organism (Bravi et al, 2011;Frasch, 2023;Herry et al, 2019;Malik et al, 1996;Shaffer & Ginsberg, 2017).…”

The value of some indices of heart rate variability in the diagnosis of fetal growth retardation

“…Водночас нелінійність -важлива умова функціонування серцево-судинної системи. Втрата нелінійности, що призводить до пригнічення ВСР, супроводжується однаковими за тривалістю серцевими циклами та появою синусоїдального ритму на кардіотокограмі [9]. При цьому серце функціонує як маятник, що описується лінійною функцією.…”

“…Безумовно, обрані величини -EnRE і D2 не можуть претендувати на повну характеристику складності ВСР. Проте, зважаючи на їхні властивості, це може бути достатнім для поточного розгляду [9,11]. Нарешті, використання нечіткої логіки (англ.…”