scholarly journals Blood pressure and heart rate variability and baroreflex sensitivity before and after brain death

2001 ◽  
Vol 71 (5) ◽  
pp. 621-631 ◽  
Author(s):  
F Conci
Author(s):  
Arundhati Goley ◽  
A. Mooventhan ◽  
NK. Manjunath

Abstract Background Hydrotherapeutic applications to the head and spine have shown to improve cardiovascular and autonomic functions. There is lack of study reporting the effect of either neutral spinal bath (NSB) or neutral spinal spray (NSS). Hence, the present study was conducted to evaluate and compare the effects of both NSB and NSS in healthy volunteers. Methods Thirty healthy subjects were recruited and randomized into either neutral spinal bath group (NSBG) or neutral spinal spray group (NSSG). A single session of NSB, NSS was given for 15 min to the NSBG and NSSG, respectively. Assessments were taken before and after the interventions. Results Results of this study showed a significant reduction in low-frequency (LF) to high-frequency (HF) (LF/HF) ratio of heart rate variability (HRV) spectrum in NSBG compared with NSSG (p=0.026). Within-group analysis of both NSBG and NSSG showed a significant increase in the mean of the intervals between adjacent QRS complexes or the instantaneous heart rate (HR) (RRI) (p=0.002; p=0.009, respectively), along with a significant reduction in HR (p=0.002; p=0.004, respectively). But, a significant reduction in systolic blood pressure (SBP) (p=0.037) and pulse pressure (PP) (p=0.017) was observed in NSSG, while a significant reduction in diastolic blood pressure (DBP) (p=0.008), mean arterial blood pressure (MAP) (p=0.008) and LF/HF ratio (p=0.041) was observed in NSBG. Conclusion Results of the study suggest that 15 min of both NSB and NSS might be effective in reducing HR and improving HRV. However, NSS is particularly effective in reducing SBP and PP, while NSB is particularly effective in reducing DBP and MAP along with improving sympathovagal balance in healthy volunteers.


2020 ◽  
Vol 30 (5) ◽  
pp. 433-439 ◽  
Author(s):  
Priyanka Garg ◽  
Kavita Yadav ◽  
Ashok Kumar Jaryal ◽  
Garima Kachhawa ◽  
Alka Kriplani ◽  
...  

2006 ◽  
Vol 16 (5) ◽  
pp. 412-417 ◽  
Author(s):  
Mathias Baumert ◽  
Lars Brechtel ◽  
J??rgen Lock ◽  
Mario Hermsdorf ◽  
Roland Wolff ◽  
...  

2011 ◽  
Vol 301 (4) ◽  
pp. H1540-H1550 ◽  
Author(s):  
Megan S. Johnson ◽  
Vincent G. DeMarco ◽  
Cheryl M. Heesch ◽  
Adam T. Whaley-Connell ◽  
Rebecca I. Schneider ◽  
...  

The aim of this investigation was to evaluate sex differences in baroreflex and heart rate variability (HRV) dysfunction and indexes of end-organ damage in the TG(mRen2)27 (Ren2) rat, a model of renin overexpression and tissue renin-angiotensin-aldosterone system overactivation. Blood pressure (via telemetric monitoring), blood pressure variability [BPV; SD of systolic blood pressure (SBP)], spontaneous baroreflex sensitivity, HRV [HRV Triangular Index (HRV-TI), standard deviation of the average NN interval (SDNN), low and high frequency power (LF and HF, respectively), and Poincaré plot analysis (SD1, SD2)], and cardiovascular function (pressure-volume loop analysis and proteinuria) were evaluated in male and female 10-wk-old Ren2 and Sprague Dawley rats. The severity of hypertension was greater in Ren2 males (R2-M) than in Ren2 females (R2-F). Increased BPV, suppression of baroreflex gain, decreased HRV, and associated end-organ damage manifested as cardiac dysfunction, myocardial remodeling, elevated proteinuria, and tissue oxidative stress were more pronounced in R2-M compared with R2-F. During the dark cycle, HRV-TI and SDNN were negatively correlated with SBP within R2-M and positively correlated within R2-F; within R2-M, these indexes were also negatively correlated with end-organ damage [left ventricular hypertrophy (LVH)]. Furthermore, within R2-M only, LVH was strongly correlated with indexes of HRV representing predominantly vagal (HF, SD1), but not sympathetic (LF, SD2), variability. These data demonstrated relative protection in females from autonomic dysfunction and end-organ damage associated with elevated blood pressure in the Ren2 model of hypertension.


2009 ◽  
Vol 6 (3) ◽  
pp. 38-56
Author(s):  
G V Ryabykina ◽  
T A Shishova ◽  
D N Laptev ◽  
V B Mychka ◽  
L N Lyutikova ◽  
...  

Aim: this study the changes of blood pressure (BP), heart rate variability (HRV) characteristics, average weighed rhythmogram variation (AWRV) and QTc in patients with metabolic syndrome (MC) and arterial hypertension (AH) before and after therapy of betablocker, metformin and their combination. Materials: 51 patients with МС and AH were enrolled in the study. The patients were randomization on 3 groups: the monotherapy of nebivolol (N) 5 mg/days (n=18), the monotherapy of metformin (M) 1700 mg/days (n=15) and nebivolol+metformin combination therapy (N+M) (n=18). The estimated variables included of BP, HRV, AWRV and QTc before and after 24 weeks of the treatment. Results: after 24 weeks of the N treatment QTc interval change from 44823 ms to 43317ms (p0.05). Treatment of M changes AWRV from 872234 ms to 761195 (p>0.05), QTc from 44825 ms to 43427 ms (p


SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A177-A177
Author(s):  
H Tsai ◽  
T Kuo ◽  
C Yang

Abstract Introduction Insomnia is a risk factor for hypertension and cardiovascular events, and this association is strongest for sleep-onset insomnia. However, little is known about insomnia on cardiovascular modulation, especially soon after morning awakening, the peak period of time for cardiovascular incidents. This study explored morning cardiovascular function in individuals with sleep-onset insomnia by analysing heart rate variability, blood pressure variability, and baroreflex sensitivity. Methods Sleep structure of the participants (15 good sleepers and 13 individuals with sleep-onset insomnia) was measured by laboratory polysomnography, followed by continuous recordings of the participant’s blood pressure and heart rate for 10 min in the morning. Results When compared to the good sleepers, the insomnia group showed significant reductions in total sleep time, a longer sleep-onset latency, and reduced sleep efficiency. The sleep structure, including durations of sleep stages, numbers of awakenings and arousal index did not differ between the groups. After morning awakening (averaged time: 12.33 ± 10.48 min), the shorter R-R intervals, lower total power, and lower high-frequency power of heart rate variability were observed among individuals with sleep-onset insomnia, compared with good sleepers. Elevated slopes of systolic and diastolic blood pressure, as well as lower baroreflex sensitivity, were also shown in the insomnia group. Indices of sympathetic activity, including low-frequency percentage of heart rate variability or low-frequency power of blood pressure variability, did not differ between the groups. Conclusion Weak vagal activity and blunted baroreflex sensitivity were evident among sleep-onset insomnia. These findings indicate difficulty in initiating sleep, without significant sleep fragmentation, can independently affect morning cardiovascular function. This study provides a possible link between sleep-onset insomnia and risk of cardiovascular events. Support N/A


2019 ◽  
Vol 33 (1) ◽  
pp. 39-53 ◽  
Author(s):  
Stefan Duschek ◽  
Alexandra Hoffmann ◽  
Casandra I. Montoro ◽  
Gustavo A. Reyes del Paso

Abstract. Chronic low blood pressure (hypotension) is accompanied by symptoms such as fatigue, reduced drive, faintness, dizziness, cold limbs, and concentration difficulties. The study explored the involvement of aberrances in autonomic cardiovascular control in the origin of this condition. In 40 hypotensive and 40 normotensive subjects, impedance cardiography, electrocardiography, and continuous blood pressure recordings were performed at rest and during stress induced by mental calculation. Parameters of cardiac sympathetic control (i.e., stroke volume, cardiac output, pre-ejection period, total peripheral resistance), parasympathetic control (i.e., heart rate variability), and baroreflex function (i.e., baroreflex sensitivity) were obtained. The hypotensive group exhibited markedly lower stroke volume, heart rate, and cardiac output, as well as higher pre-ejection period and baroreflex sensitivity than the control group. Hypotension was furthermore associated with a smaller blood pressure response during stress. No group differences arose in total peripheral resistance and heart rate variability. While reduced beta-adrenergic myocardial drive seems to constitute the principal feature of the autonomic impairment that characterizes chronic hypotension, baroreflex-related mechanisms may also contribute to this state. Insufficient organ perfusion due to reduced cardiac output and deficient cardiovascular adjustment to situational requirements may be involved in the manifestation of bodily and mental symptoms.


Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Li Xiong ◽  
Ge Tian ◽  
Xiangyan Chen ◽  
Howan Leung ◽  
Thomas Leung ◽  
...  

Background and Objectives: Blood pressure variability (BPV), heart rate variability (HRV) and baroreflex sensitivity (BRS) as measures of autonomic function might provide prognostic information in ischemic stroke. We aimed to study noninvasive beat-to-beat assessment of BPV, HRV and BRS in the acute phase of ischemic stroke to determine whether any of them predicted clinical outcome. Methods & Patients: Consecutive ischemic stroke patients within 7 days of symptom onset were enrolled. The frequency components of BPV and HRV by means of power spectral analysis [very low frequency (VLF; < 0.04 Hz); low frequency (LF; 0.04-0.15 Hz); high frequency (HF; 0.15-0.40 Hz); power spectral density (PSD; <0.40 Hz) and LF/HF ratio] were calculated from 10-minute recordings of beat-to-beat blood pressure and heart rate monitoring. The baroreflex slope and baroreflex effectiveness index (BEI) were determined using the sequence method for BRS. Clinical outcome was assessed at 3 months after stroke onset as good or poor by modified Rankin Scale (mRS) (good outcome, mRS ≤ 2). Results: 82 patients were recruited (mean age, 64.6 ± 9.9 years; 89.3% males). Univariate analysis showed that there were significant differences in National Institutes of Health Stroke Scale (NIHSS) at recruitment, VLF diastolic BPV, VLF, HF and PSD systolic BPV, and down ramp BEI between the good and poor outcome groups (all P < 0.05). After adjusting for NIHSS, multivariate logistic regression showed that only HF systolic BPV (OR 1.320; 95% CI, 1.050-1.659; P=0.017) and down BEI (OR 0.950; 95% CI, 0.912-0.990; P=0.014) were independently correlated with poor functional outcome. Conclusions: Beat-to beat highly variable systolic blood pressure and impaired BRS as evaluated by decreased down BEI are associated with an unfavorable functional outcome after acute ischemic stroke. Important prognostic information can be readily obtained from a short period of noninvasive hemodynamics monitoring in the acute stroke patient.


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