Do physiological and pathological stresses produce different changes in heart rate variability?

Abstract

Although physiological (e.g., exercise) and pathological (e.g., infection) stress affecting the cardiovascular system have both been documented to be associated with a reduction in overall heart rate variability (HRV), it remains unclear if loss of HRV is ubiquitously similar across different domains of variability analysis or if distinct patterns of altered HRV exist depending on the stressor. Using Continuous Individualized Multiorgan Variability Analysis (CIMVA™) software, heart rate (HR) and four selected measures of variability were measured over time (windowed analysis) from two datasets, a set (n = 13) of patients who developed systemic infection (i.e., sepsis) after bone marrow transplant (BMT), and a matched set of healthy subjects undergoing physical exercise under controlled conditions. HR and the four HRV measures showed similar trends in both sepsis and exercise. The comparison through Wilcoxon sign-rank test of the levels of variability at baseline and during the stress (i.e., exercise or after days of sepsis development) showed similar changes, except for LF/HF, ratio of power at low (LF) and high (HF) frequencies (associated with sympathovagal modulation), which was affected by exercise but did not show any change during sepsis. Furthermore, HRV measures during sepsis showed a lower level of correlation with each other, as compared to HRV during exercise. In conclusion, this exploratory study highlights similar responses during both exercise and infection, with differences in terms of correlation and inter-subject fluctuations, whose physiologic significance merits further investigation.

Heart Rate and Cardiovascular Responses to Commercial Flights: Relationships with Physical Fitness

“…However, to date there has been no consensus regarding the impact of the different components of physical fitness on HRV modulation during stress responses (Hautala et al, 2010; Bravi et al, 2013). We identified significant relationships between high HRV (absolute and change) and high aerobic fitness (MAS), and low % body fat.…”

Correlation between the motility of the proximal antrum and the high‐frequency power of heart rate variability in freely moving rats

“…Heart rate variability (HRV) is a non-invasive approach to measure autonomic tone, 1 and variations in HRV have been associated with increased risk of pathologies and all-cause mortality. [1][2][3][4][5][6][7] The high-frequency power spectrum of HRV (HF-HRV) measures cardiac vagal tone, and studies have shown that decreases in parasympathetic vagal tone are associated with increased allostatic load and adverse health outcomes such as sepsis, necrotizing enterocolitis, chronic obstructive pulmonary disease, and peripheral artery disease, to name a few. 6,[8][9][10][11] Vagal output to the heart originates from brainstem neurons located in the nucleus ambiguous, 12 where neurons fire action potentials rhythmically, in a pattern similar to the respiratory rate.…”

Diminished vagal tone is a predictive biomarker of necrotizing enterocolitis‐risk in preterm infants

“…8 In particular, the high frequency (HF) spectrum provides a reliable reflection of parasympathetic modulation, i.e., vagal tone, 9 which is associated with the maintenance of physiological homeostasis. Many studies have shown that HRV and vagal tone decrease in anxiety, stress, and inflammation/sepsis [10][11][12][13][14][15][16] ; indeed, the vagus also plays a critical role in the cholinergic anti-inflammatory reflex, 17,18 which has been shown to confer protection against tissue damage in many GI-related inflammatory diseases, including acute pancreatitis, colitis, and inflammatory bowel disease. [19][20][21] While HF-HRV provides a direct, non-invasive measure of vagal efferent activity 8 , additional potentially useful indirect measures of vagal activity on the cholinergic anti-inflammatory reflex include blood sampling for C-reactive protein and cytokine analysis.…”