Baroreflex sensitivity in frailty syndrome

Abstract

Frailty is related to a decrease in the physiological reserves, which causes difficulties in maintaining homeostasis. An example of physiological mechanisms for cardiovascular homeostasis is the baroreflex. The aim of this study was to compare baroreflex among frail, prefrail, and nonfrail individuals, in supine and orthostatic positions. Community-dwelling older adults were evaluated and categorized into frail, prefrail, or nonfrail groups, according to frailty phenotype. The RR interval (RRi) and systolic blood pressure (SBP) series were recorded for 15 min in the supine and 15 min in the orthostatic positions. Mean and variance of RRi and SBP, and baroreflex evaluated by phase, gain (α), and coherence (K 2 ) were determined. A two-way repeated measures ANOVA, with Tukey's post hoc, was applied for group, position, and their interaction effects. The significance level established was 5%. Prefrail and frail participants did not present a significant decrease in mean values of RRi after postural challenge (893.43 to 834.20 ms and 925.99 to 857.98 ms, respectively). Frail participants showed a reduction in RRi variance in supine to orthostatic (852.04 to 232.37 ms 2 ). Prefrail and frail participants showed a decrease in K 2 after postural change (0.69 to 0.52 and 0.54 to 0.34, respectively). Frail participants exhibited lower values of K 2 (0.34) compared to nonfrail and prefrail participants (0.61 and 0.52, respectively). Baroreflex indicated the presence of decoupling between heart period and SBP in frail and prefrail. Thus, reduced K 2 might be a marker of the frailty process.

Associations between Neurocardiovascular Signal Entropy and Physical Frailty

“…Heart rate variability complexity is generally expected to decrease with pathology [ 51 ]; however, in the present work, higher entropy in both BP and HR were found to be associated with increased frailty. We postulate that entropy calculated in short length neurocardiovascular data, as reported herein, is not measuring system flexibility, but rather systemic disorder, or “jitter”, resulting from dysregulation of the neurocardiovascular system.…”

Multicomponent exercise training in cardiovascular complexity in prefrail older adults: a randomized blinded clinical pilot study

“…An example of this is the orthostatic hypotension described in frail individuals ( 33 ). Considering that the baroreflex represents an interaction among control subsystems responsible for BP homeostasis ( 34 ), in agreement with a previous study ( 12 ), our data suggested there is also an impairment in BRS in prefrail individuals.…”

“…In this sense, one of the physiological systems most studied is the cardiovascular system (7,9). It has already been demonstrated that frail older adults present impairment in cardiac complexity (5,10,11) and in BRS (12).…”

Association between preoperative autonomic nervous system function and post-induction hypotension in elderly patients: a protocol for a cohort study

“…We will also perform frailty assessment in elderly patients to explore the role of frailty in the association of autonomic regulation and PIH. 24 Overall, this cohort study will provide the relationship between perioperative assessment of autonomic function and outcomes.…”