Interaction between Heart Rate and Heart Rate Variability

Abstract

Heart rate variability (HRV) is significantly associated with average heart rate (HR), therefore, HRV actually provides information on two quantities, that is, on HR and its variability. It is difficult to conclude which of these two plays a principal role in the HRV clinical value, or in other words, what is the HR contribution to the clinical significance of HRV. Moreover, the association between HRV and HR is both a physiological phenomenon and a mathematical one. The physiological HRV dependence on HR is determined by the autonomic nervous system activity, but the mathematical one is caused by the nonlinear relationship between RR interval and HR. By employing modification methods of the HRV and HR relationship, it is possible to investigate the HR contribution to the HRV clinical value. Recent studies have shown that the removal of the HR impact on HRV makes HRV more predictive for noncardiac death, however, the enhancement of this impact causes HRV to be a better predictor of cardiovascular mortality. Thus, HR seems to constitute a cardiovascular factor of the HRV predictive ability. HR also influences the reproducibility of HRV, therefore, HR changes should be considered when one compares HRV measurements in a given patient. This review summarizes methodological aspects of investigations of the HRV and HR interaction as well as latest observations concerning its clinical utility. The issues discussed in this article should also refer to any other heart rate dynamics analysis which indices are significantly associated with HR.Ann Noninvasive Electrocardiol 2014;19(3):207-216 heart rate; heart rate variability; autonomic nervous system; risk prediction; mortalityHeart rate variability (HRV) has been extensively investigated for many years in both clinical and experimental settings and turns out to be a valuable predictor of adverse outcomes in various diseases. 1-5 Average heart rate (HR) is another risk factor which proved to be especially efficient in predicting cardiovascular events.6-8 It is commonly known that HRV is significantly associated with HR, 9, 10 therefore, HRV actually provides information on two quantities, that is, on HR and its variability. 11,12 It is hard to conclude which of these two plays a principal role in the HRV prognostic value, or in other words, what is the HR contribution to prognostic power of HRV.12 This is even more important, since HR is a therapeutic target and recently new options of such a treatment have been implemented to the clinical practice 7, 13-15 -therefore, our understanding of the HRV dependence on HR becomes relevant for future therapeutic studies. This review summarizes Address for correspondence : Jerzy Sacha, M.D., Department of Cardiology, Regional Medical Center, Al. Witosa 26, PHYSIOLOGICAL AND MATHEMATICAL INTERACTION BETWEEN HRV AND HRThe association between HRV and HR is both a physiological phenomenon and a mathematical one. The physiological HRV dependence on HR is determined by the autonomic nervous system activity, that is, the higher parasymp...

Short-term pulse rate variability is better characterized by functional near-infrared spectroscopy than by photoplethysmography

“…In 1996, a task force 31 specified standards for calculating PRV measures and reporting results, which have been considered in the present study. Accuracy of the ECG has since then been investigated in numerous studies in health and disease, [1][2][3][4] and the correlation with both PRV PPG 7 and PRV NIRS 25 under resting conditions has been reported to be high.…”

“…The usefulness of HRV as a tool for basic research as well as for medical diagnostic purposes to assess the function of the autonomic nervous system has been verified in numerous studies. [1][2][3][4] The gold standard is the analysis of interbeat (RR) intervals derived from electrocardiography (ECG). Alternatively, pulse cycle intervals variability based on blood flow pulsations (i.e., PRV) can be derived from pulse oximetry, i.e., photoplethysmography (PPG) (PRV PPG ).…”

Toll-like receptor 9 plays a key role in the autonomic cardiac and baroreflex control of arterial pressure

“…O'Connor et al (66) have demonstrated, by HR variability studies, that IL-6 expression in monocytes in women induced by TLR4 stimulation with LPS, was negatively associated with sympathovagal balance (LF/HF ratio) and that the vagal tone (HF power) was positively associated with the production of this cytokine, suggesting that IL-6 production may be related to sympathovagal balance or vagal tone. Sacha (90) suggests that HR variability is significantly associated with average HR. As in the present study, the mean HR in TLR9 KO mice was much lower than WT mice, the lower baseline HR in TLR9 KO mice would explain the increased HR variability in this strain of mice.…”

Beat Rate Variability in Murine Embryonic Stem Cell-Derived Cardiomyocytes: Effect of Antiarrhythmic Drugs

“…In order to remove this influence, it is recommended to divide the HRV indices by the corresponding mean normal-tonormal interval [31]. For this reason, the coefficient of variation (CV, SDNN divided by the mean normal-tonormal interval) was included into the analysis of this study.…”