Assessing Correlation between Heart Rate Variability Markers Based on Laguerre Expansion and Direct Measures of Sympathetic Activity during Incremental Head-up Tilt

2021 ◽  
Author(s):  
Vlasta Bari ◽  
Beatrice De Maria ◽  
Beatrice Cairo ◽  
Francesca Gelpi ◽  
Elisabeth Lambert ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Sympathetic Activity ◽  
Laguerre Expansion ◽  
Head Up Tilt ◽  
Direct Measures

scholarly journals Heart rate variability: Response to graded head up tilt in healthy men

1970 ◽  
Vol 7 (3) ◽  
pp. 252-257 ◽  
Author(s):  
P Sharma ◽  
BH Paudel ◽  
PN Singh ◽  
P Linmbu
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Sympathetic Activity ◽  
Cycle Length ◽  
Cardiac Cycle ◽  
Test Results ◽  
Successive Cycle ◽  
Head Up Tilt ◽  
Bonferroni Test ◽  
Lying Down

Background: Heart rate variability is actually a misnomer for R to R variability in cardiac cycle. Variation in successive cycle length is called the heart rate variability (HRV). Head-up tilt is a model of studying cardiovascular haemodynamics, which reflects in heart rate variability (HRV). Objectives: To study the effect of 10° and 70° head-up tilt on HRV. Materials and methods: The study was done in the Department of Physiology using graded head up tilt (passive orthostatism). HRV measurement was done at 10° and 70° tilt and compared with supine using standardised methods on 30 consenting healthy males (age 25.37±3.89 years). The HRV variables across postures were compared by ANOVA and Bonferroni test. Results: The heart rate increased at 70° compared to 10° and supine (70.48±8.17 Vs 70.22±8.67 and 88.51±12.84 bpm, p<0.001). The 70° tilt decreased vagal HRV indicators compared to 10° and supine: SDNN (31.13±8.12 Vs 38.07±11.29 and 38.13±10.89 ms, p<0.05), RMSSD (20.06 ±8.47 Vs 34.23±14.22 and 36.16±12.22 ms, p<0.001), NN50 count (13.03±20.58 Vs 45.07±44.44 and 55.27±44.10, p<0.01), pNN50 (3.28±6.08 Vs 14.06±15.65 and 16.65±14.23, p<0.01), HF power (197.20±143.76 Vs 218.17±155.85 and 216.87±150.98 Hz, p<0.05), HFnu unit (24.28±14.16 Vs 45.48±16.34 and 47.67±19.89, p<0.001). The 70° tilt increased LF power% (197.20±143.76 Vs 218.17±155.85 and 216.87±150.98, p<0.001). LFnu unit (75.72±14.76 Vs 54.52±16.34 and 52.32±19.89, p<0.001), LF: HF (4.96±4.08 Vs 1.53±1.138 and 1.69±1.67, p<0.001) compared to 10° and supine. Conclusion: At 70° tilt, HRV measures, reflecting vagal contribution to cardiac-cycle length, decreased with reciprocal increase in sympathetic activity compared to 10° or supine leading to increase in sympathetic predominance. A 10° tilt, which is almost equivalent to lying down with pillow, did not change HRV from supine. Key words: Cardiac cycle; cardiovascular haemodynamics; head-up-tilt; heart rate variability; sympathetic activity; parasympathetic activity DOI: 10.3126/kumj.v7i3.2733 Kathmandu University Medical Journal (2009) Vol.7, No.3 Issue 27, 252-257

scholarly journals Role of increased sympathetic activity in the genesis of ambulatory ischemia: Spectral analysis of heart rate variability

1996 ◽  
Vol 27 (2) ◽  
pp. 398-399
Author(s):  
Tohru Kaji ◽  
Tetsuro Kohya ◽  
Fumishi Tomita ◽  
Tomohide Ono ◽  
Akira Kitabatake
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Analysis ◽  
Sympathetic Activity

scholarly journals Effect of Hypoglycemia on Heart Rate Variability in People with Type 1 Diabetes and Impaired Awareness of Hypoglycemia

2021 ◽  
pp. 193229682110074
Author(s):  
Mats Koeneman ◽  
Marleen Olde Bekkink ◽  
Lian van Meijel ◽  
Sebastian Bredie ◽  
Bastiaan de Galan
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Sympathetic Activity ◽  
Elevated Risk ◽  
Wilcoxon Rank Sum Test ◽  
Impaired Awareness ◽  
Induced Changes ◽  
Measurable Change

Background: People with impaired awareness of hypoglycemia (IAH) are at elevated risk of severe, potentially hazardous, hypoglycemia and would benefit from a device alerting to hypoglycemia. Heart rate variability (HRV) changes with hypoglycemia due to sympathetic activity. Since IAH is associated with suppressed sympathetic activity, we investigated whether hypoglycemia elicits a measurable change in HRV in patients with T1D and IAH. Method: Eligible participants underwent a modified hyperinsulinemic euglycemic hypoglycemic clamp (glucose nadir, 43.1 ± 0.90 mg/dl), while HRV was measured by a VitalConnect HealthPatch. Measurements of HRV included Root Mean Square of the Successive Differences (RMSSD) and low to high frequency (LF:HF) ratio. Wilcoxon rank-sum test was used for testing within-subject HRV changes. Results: We included 12 participants (8 female, mean age 57 ± 12 years, mean HbA1c 57 ± 5 mmol/mol (7.4 ± 0.4%)). Symptoms increased from 4.0 (1.5-7.0) at euglycemia to 7.5 (5.0-11.0) during hypoglycemia ( P = .003). In response to hypoglycemia, the LF:HF ratio and RMSSD increased when normalized for data obtained during euglycemia (both P < .01). The LF:HF ratio increased in 6 participants (50%) and declined in one other participant (8%). The RMSSD decreased in 3 (25%) and increased in 4 (33%) participants. In 2 patients, no change in HRV could be detected in response to hypoglycemia. Conclusions: This study reveals that hypoglycemia-induced changes in HRV are retained in the majority of people with T1D and IAH, and that these changes can be detected by a wearable device. Real-time HRV seems usable for detection of hypoglycemia in patients with IAH.

scholarly journals Cardiac Parasympathetic Withdrawal and Sympathetic Activity: Effect of Heat Exposure on Heart Rate Variability

2021 ◽  
Vol 18 (11) ◽  
pp. 5934
Author(s):  
Oriol Abellán-Aynés ◽  
Pedro Manonelles ◽  
Fernando Alacid
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Environmental Conditions ◽  
Sympathetic Activity ◽  
Heat Exposure ◽  
Repeated Measurements ◽  
Control Group ◽  
Poincaré Plot ◽  
Activity Effect ◽  
And Control

(1) Background: Research on heart rate variability has increased in recent years and the temperature has not been controlled in some studies assessing repeated measurements. This study aimed to analyze how heart rate variability may change based on environmental temperature during measurement depending on parasympathetic and sympathetic activity variations. (2) Methods: A total of 22 volunteers participated in this study divided into an experimental (n = 12) and control group (n = 10). Each participant was assessed randomly under two different environmental conditions for the experimental group (19 °C and 35 °C) and two identical environmental conditions for the control group (19 °C). During the procedure, heart rate variability measurements were carried out for 10 min. (3) Results: Significantly changes were observed for time and frequency domains as well as Poincaré plot variables after heat exposure (p < 0.05). These findings were not observed in the control group, whose conditions between measurements did not change. (4) Conclusions: The reduction of heart rate variability due to exposure to hot conditions appears to be produced mostly by a parasympathetic withdrawal rather than a sympathetic activation. Therefore, if consecutive measurements have to be carried out, these should always be done under the same temperature conditions.

scholarly journals Sympathetic activity, assessed by power spectral analysis of heart rate variability, in white-coat, masked and sustained hypertension versus true normotension

2007 ◽  
Vol 25 (11) ◽  
pp. 2280-2285 ◽  
Author(s):  
Robert H Fagard ◽  
Katarzyna Stolarz ◽  
Tatiana Kuznetsova ◽  
Jitka Seidlerova ◽  
Valérie Tikhonoff ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Analysis ◽  
Sympathetic Activity ◽  
Power Spectral Analysis ◽  
White Coat ◽  
Sustained Hypertension ◽  
Power Spectral

scholarly journals Heart rate variability in athletes and nonathletes at rest and during head-up tilt

2005 ◽  
Vol 38 (4) ◽  
pp. 639-647 ◽  
Author(s):  
F.S. Martinelli ◽  
M.P.T. Chacon-Mikahil ◽  
L.E.B. Martins ◽  
E.C. Lima-Filho ◽  
R. Golfetti ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Head Up Tilt

Comparative evaluation of the antistress effect of phenazepam, melatonin and their combination

2021 ◽  
Vol 19 (1) ◽  
pp. 107-110
Author(s):  
Eduard B. Arushanian ◽  
Olga Vladimirovna ◽  
Eduard Vladimirovich Beyer
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Sympathetic Activity ◽  
Comparative Evaluation ◽  
Anxiolytic Effect ◽  
Antistress Effect

Phenazepam and melatonin reduce anxiety in stressed rats, and their anxiolytic effect is enhanced in combination. Melatonin also limits stress-induced increases in sympathetic activity and eliminates the dysregulatory effect of phenazepam on the main indicators of heart rate variability.

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