scholarly journals Análise dos Índices Espectrais da Variabilidade da Frequência Cardíaca Durante a Mudança Postural de Idosos Hipertensos

2018 ◽  
Vol 20 (2) ◽  
pp. 146 ◽  
Author(s):  
Ariane Hidalgo Mansano Pletsch ◽  
Alderico Rodrigues De Paula Júnior ◽  
Nelson José Freitas da Silveira ◽  
Walkiria Shimoaya-Bittencourt ◽  
Rodrigo Aléxis Lazo Osório

ResumoO estudo da Variabilidade da Frequência Cardíaca (VFC) tem permitido, de forma não invasiva, avaliar o Sistema Nervoso autônomo e o risco cardíaco, sendo um importante indicador prognóstico de doenças cardíacas e sistêmicas. O objetivo foi avaliar e comparar a VFC no domínio da frequência e do tempo de idosos com hipertensão arterial e de idosos saudáveis frente à mudança postural de repouso para sentado. Foram estudados 18 indivíduos hipertensos e 18 indivíduos saudáveis na faixa etária de 60 a 85 anos. A frequência cardíaca e os intervalos R-R foram coletados pelo instrumento Polar S810i durante 1200 s nas posturas supina e sentada. A VFC foi analisada no domínio do tempo - DT pelas variáveis: Índice raiz quadrada da média dos quadrados das diferenças entre intervalos R-R (iR-R) sucessivos (RMSSD), desvio padrão da média dos iR-R normais em ms - SDNN e PNN50%, que traduz a diferença de duração superior a 50 milissegundos, e no domínio da frequência, pelas bandas de alta (AF) e baixa frequência (BF), e da razão BF/AF. Ocorreu alteração na VFC dos idosos tanto no grupo controle e hipertenso, no entanto não houve mudanças significativas na VFC entre os grupos estudados. Ao analisar a VFC no domínio do tempo, o estudo mostrou que a amostragem estudada apresenta alto risco cardíaco ao analisar o parâmetro SDNN. Conclui-se que a mudança postural alterou a VFC desses idosos, tanto no grupo controle e hipertenso, no entanto não houve mudanças significativas na VFC entre as fases dos grupos estudados e obteve-se como resultado alto risco cardíaco ao avaliar o parâmetro SDNN em ambos os grupos.Palavras-chave: Hipertensão. Idoso. Frequência Cardíaca.AbstractThe study of heart rate variability (HRV) allows noninvasive way to evaluate the autonomic nervous system and cardiac risk, and an important prognostic indicator of heart and systemic diseases disease. The objective was to evaluate and compare the HRV in the frequency and duration of elderly patients with hypertension and healthy elderly versus postural change in the condition of rest. The study comprised 18 hypertensive individuals and 18 healthy subjects aged 60 to 85 years, both sexes. Heart rate and RR intervals were collected by the instrument Polar S810i during 1200 s in supine and sitting postures. HRV was analyzed in time domain indices SDNN, RMSSD and PNN50% and the frequency domain, by bands of high (AF) and low frequency (LF), and the ratio LF / HF. Intergroup intra-analyes were used as well as the tests of normality D’Augustine as a criterion for parametric groups. There was change in heart rate variability of both the elderly and hypertensive patients in the control group, however there were no significant changes in studied HRV intergroups . In the area of the time it was found that the sampling shows high-risk cardiac parsing the parameter SDNN. The results showed that the change posture changed the variability of heart rate in the control group and hypertension, however there were no significant changes in HRV among the phases of the groups and a high risk was obtained as a result of the parameter SDNN for both heart the groups.Keywords: Hypertension. Aged. Heart Rate.

2014 ◽  
Vol 2014 ◽  
pp. 1-19 ◽  
Author(s):  
Joanne W. Y. Chung ◽  
Vincent C. M. Yan ◽  
Hongwei Zhang

Aim.To summarize all relevant trials and critically evaluate the effect of acupuncture on heart rate variability (HRV).Method.This was a systematic review with meta-analysis. Keyword search was conducted in 7 databases for randomized controlled trials (RCTs). Data extraction and risk of bias were done.Results.Fourteen included studies showed a decreasing effect of acupuncture on low frequency (LF) and low frequency to high frequency ratio (LF/HF ratio) of HRV for nonhealthy subjects and on normalized low frequency (LF norm) for healthy subjects. The overall effect was in favour of the sham/control group for high frequency (HF) in nonhealthy subjects and for normalized high frequency (HF norm) in healthy subjects. Significant decreasing effect on HF and LF/HF ratio of HRV when acupuncture was performed on ST36 among healthy subjects and PC6 among both healthy and nonhealthy subjects, respectively.Discussion.This study partially supports the possible effect of acupuncture in modulating the LF of HRV in both healthy and nonhealthy subjects, while previous review reported that acupuncture did not have any convincing effect on HRV in healthy subjects. More published work is needed in this area to determine if HRV can be an indicator of the therapeutic effect of acupuncture.


2019 ◽  
Vol 18 (8) ◽  
pp. 658-666 ◽  
Author(s):  
Ching-Hsiang Chen ◽  
Kuo-Sheng Hung ◽  
Yu-Chu Chung ◽  
Mei-Ling Yeh

Background: Stroke, a medical condition that causes physical disability and mental health problems, impacts negatively on quality of life. Post-stroke rehabilitation is critical to restoring quality of life in these patients. Objectives: This study was designed to evaluate the effect of a mind–body interactive qigong intervention on the physical and mental aspects of quality of life, considering bio-physiological and mental covariates in subacute stroke inpatients. Methods: A randomized controlled trial with repeated measures design was used. A total of 68 participants were recruited from the medical and rehabilitation wards at a teaching hospital in northern Taiwan and then randomly assigned either to the Chan-Chuang qigong group, which received standard care plus a 10-day mind–body interactive exercise program, or to the control group, which received standard care only. Data were collected using the National Institutes of Health Stroke Scale, Hospital Anxiety and Depression Scale, Short Form-12, stroke-related neurologic deficit, muscular strength, heart rate variability and fatigue at three time points: pre-intervention, halfway through the intervention (day 5) and on the final day of the intervention (day 10). Results: The results of the mixed-effect model analysis showed that the qigong group had a significantly higher quality of life score at day 10 ( p<0.05) than the control group. Among the covariates, neurologic deficit ( p=0.04), muscle strength ( p=0.04), low frequency to high frequency ratio ( p=0.02) and anxiety ( p=0.04) were significantly associated with changes in quality of life. Conversely, heart rate, heart rate variability (standard deviation of normal-to-normal intervals, low frequency and high frequency), fatigue and depression were not significantly associated with change in quality of life ( p >0.05). Conclusions: This study supports the potential benefits of a 10-day mind–body interactive exercise (Chan-Chuang qigong) program for subacute stroke inpatients and provides information that may be useful in planning adjunctive rehabilitative care for stroke inpatients.


2008 ◽  
Vol 17 (6) ◽  
pp. 575-583 ◽  
Author(s):  
Shih-Fong Huang ◽  
Po-Yi Tsai ◽  
Wen-Hsu Sung ◽  
Chih-Yung Lin ◽  
Tien-Yow Chuang

Sympathovagal modulation during immersion in a virtual environment is an important influence on human performance of a task. The aim of this study is to investigate sympathovagal modulation using heart rate variability and perceived exertion during exercise in a virtual reality (VR) environment. Sixteen young healthy volunteers were tested while using a stationary bicycle and maintained at an anaerobic threshold intensity for exercise sessions of approximately 10 min duration. Four randomized viewing alternatives were provided including desktop monitor, projector, head mounted device (HMD), and no simulation display. The “no simulation display” served as the control group. A quick ramp exercise test was conducted and maintained at an anaerobic threshold intensity for each session to evaluate power spectral density and rating of perceived exertion (RPE). The sampled heart rate data were rearranged by cubic spline interpolation into power spectrums spanning the ultra-low frequency (ULF) to high frequency (HF) range. A significant difference was found between the no-display and projector groups for total power (TP) and very low frequency (VLF) components. In particular, there was a significant difference when comparing HMD and no-display exercise RPE curves within 6 min of cycling and at the termination of the exercise. A significant difference was also achieved in projector vs. control group comparison at the termination of the exercise. Our results indicate that the use of HMD and the projected VR during cycling can reduce the TP and VLF power spectral density through a proposed decrease in the renin-angiotensin system, with the implication that this humoral effect may enable anaerobic exercise for longer durations through a reduction in sympathetic tone and subsequent increased blood flow to the muscles.


2021 ◽  
Vol 10 (2) ◽  
pp. 65-72
Author(s):  
Tso-Yen Mao ◽  
◽  
Chun-Feng Huang ◽  
De-Yen Liu ◽  
Chien-Ting Chen ◽  
...  

This study compares the effects of the uptake or inhalation of 50uL Mentha piperita (MP) essential oil for 10 days on heart rate variability (HRV) and cardiopulmonary regulation during various exercise intensities. Forty-eight healthy male subjects were randomly assigned to MP uptake (MPU; n=16), MP inhalation (MPI; n=16), and control group (C; n=16). All participants were measured resting HRV, respiratory, cardiovascular, and metabolic parameters during aerobic, anaero- bic, and graded exercise tests (GXT) before and after treatment. There were significant increases in the low-frequency area (LFa; 1.8±0.1 vs 2.2±0.2 ms²), the ratio of low frequency to respiration frequency area (LFa/RFa; 0.9±0.1 vs 1.3±0.1) at resting and carbon dioxide production (VCO 2 ; 41.2±4.0 vs 49.2±6.8 mL/min -1 /kg -1 ), ventilation per minute (V E ; 80.2±4.3 vs 97.5±5.5 L/min -1 ), and respiratory rate (RR; 38.2±1.9 to 44.3±2.1 breath/min -1 ) in an anaerobic test following MPU inter- vention. In GXT, maximal carbon dioxide production (VCO 2max; 51.9±3.5 to 59.1±6.4 mL/min -1 /kg -1 ), maximal ventilation per minute (V Emax ; 126.4±6.5 to 138.4±5.4 L/min -1 ) and maximal respiratory rate (RR max ; 52.7±3.6 to 60.1±2.3 breath/min -1 ) significantly increased in MPU. The correlations of ΔLFa with ΔVCO 2max , ΔV Emax , and ΔRR max in the MPU group were signifi- cant. Continuous uptake or inhalation of 50uL MP oil for 10 days does not improve aerobic capacity and maximal exercise performance, but 10 days’ uptake of MP essential oil increased sympathetic activity at rest and may relate to respiratory regulation under high-intensity exercise.


2021 ◽  
Author(s):  
Jessica Marotta ◽  
Carla Piano ◽  
VALERIO BRUNETTI ◽  
Danilo Genovese ◽  
Anna Rita Bentivoglio ◽  
...  

Introduction Autonomic dysfunction has been reported as one of non-motor manifestations of both pre-symptomatic and manifest Huntington’s Disease (HD). The aim of our study was to evaluate heart rate variability (HRV) during wake and sleep in a cohort of patients with manifest HD. Methods Thirty consecutive patients with manifest HD were enrolled, 14 men and 16 women, mean age 57.3±12.2 years. All patients underwent full-night attended video-polysomnography. HRV was analyzed during wake, NREM and REM sleep, in time and frequency domain. Results were compared with a control group of healthy volunteers matched for age and sex. Results During wake HD patients presented significantly higher mean heart rate than controls (72.4±9.6 vs 58.1±7.3 bpm; p<0.001). During NREM sleep, HD patients showed higher mean heart rate (65.6±11.1 vs 48.8±4.6 bpm; p<0.001) and greater Low Frequency (LF) component of HRV (52.9±22.6 vs 35.5±17.3 n.u.; p=0.004). During REM sleep, we observed lower standard deviation of the R-R interval (SDNN) in HD subjects (3.4±2.2 vs 3.7±1.3 ms; p=0.015). Conclusion Our results showed that HD patients have higher heart rate than controls, during wake and NREM, but not during REM sleep. Among HRV variability parameters, the most relevant difference regarded the LF component, which reflects, at least partially, the ortho-sympathetic output. Our results confirm the involvement of autonomic nervous system in HD and demonstrate that it is evident during both wake and sleep.


2021 ◽  
Vol 12 ◽  
Author(s):  
Patrick R. Steffen ◽  
Derek Bartlett ◽  
Rachel Marie Channell ◽  
Katelyn Jackman ◽  
Mikel Cressman ◽  
...  

IntroductionApproaches to improve heart rate variability and reduce stress such as breathing retraining are more frequently being integrated into psychotherapy but little research on their effectiveness has been done to date. Specifically, no studies to date have directly compared using a breathing pacer at 6 breaths per minute with compassion focused soothing rhythm breathing.Current StudyIn this randomized controlled experiment, 6 breaths per minute breathing using a pacer was compared with compassion focused soothing rhythm breathing, with a nature video being used as a control group condition.MethodsHeart rate variability (HRV) measures were assessed via electrocardiogram (ECG) and respiration belt, and an automated blood pressure machine was used to measure systolic diastolic blood pressure, and heart rate (HR). A total of 96 participants were randomized into the three conditions. Following a 5-min baseline, participants engaged in either 6 breath per minute breathing, soothing rhythm breathing, or watched a nature video for 10 min. To induce a stressful state, participants then wrote for 5 min about a time they felt intensely self-critical. Participants then wrote for 5 min about a time they felt self-compassionate, and the experiment ended with a 10-min recovery period.ResultsConditions did not significantly differ at baseline. Overall, HRV, as measured by standard deviation of NN intervals (SDNN), low frequency HRV (LF HRV), and LF/HF ratio, increased during the intervention period, decreased during self-critical writing, and then returned to baseline levels during the recovery period. High frequency HRV (HF HRV) was not impacted by any of the interventions. The participants in the 6 breath per minute pacer condition were unable to consistently breathe at that rate and averaged about 12 breaths per minute. Time by Condition analyses revealed that both the 6 breaths per minute pacer and soothing breathing rhythm conditions lead to significantly higher SDNN than the nature video condition during breathing practice but there were no significant differences between conditions in response to the self-critical and self-compassionate writing or recovery periods. The 6 breath per minute pacer condition demonstrated a higher LF HRV and LF/HF ratio than the soothing rhythm breathing condition, and both intervention conditions had a higher LF HRV and LF/HF ratio than the nature video.ConclusionsAlthough the 6 breath per minute pacer condition participants were not able to breath consistently at the low pace, both the participants attempting to breathe at 6 breaths per minute as well as those in the soothing rhythm breathing condition effectively increased HR variability as measured by SDNN, and attempting to breathe at 6 breaths per minute led to the highest LF HRV and LF/HF ratio. Both breathing approaches impacted HRV more than watching a relaxing nature video and can potentially be used as key adjuncts in psychotherapy to aid in regulating physiological functioning, although it appears that consistent breathing practice would be needed.


2015 ◽  
pp. 487-493 ◽  
Author(s):  
D. POULIKAKOS ◽  
D. BANERJEE ◽  
M. MALIK

T wave morphology (TWM) descriptors derived from Holter electrocardiograms during hemodialysis (HD) are of potential value for cardiac risk assessment in HD patients. Our knowledge on autonomic regulation of TWM descriptors is limited. The purpose of this study was to investigate the association between TWM parameters and heart rate variability (HRV) during intradialytic monitoring. In each of 81 patients on maintenance HD, continuous electrocardiograms were recorded 5 times during HD on alternate weeks. TWM descriptors were calculated every 5 s in overlapping 10-s ECG segments and Low Frequency (LF) (0.04 Hz to 0.15 Hz), High Frequency (HF) (0.15 Hz to 0.40 Hz) powers of the spectrum of HRV were calculated every five min. The calculated values of TWM and HRV were averaged during the first hour of the recordings and subsequently over all recordings in each subject. Analyzable data for HRV and TWM were available in 71 HD patients (aged 61±15, 36 % diabetics, 32 % females). LF in normalized units correlated positively with Total Cosine R to T (r=0.374, p=0.001) and negatively with T wave morphology dispersion (r=−0.253, p=0.033) after adjusting for heart rate. A heart rate independent association between repolarisation descriptors and HRV exists in HD patients. Autonomic modulation needs to be considered when using TWM characteristics for risk profiling of HD patients.


1998 ◽  
Vol 76 (7-8) ◽  
pp. 806-810 ◽  
Author(s):  
Yaariv Khaykin ◽  
Paul Dorian ◽  
Anthony Tang ◽  
M Green ◽  
Jan Mitchell ◽  
...  

Zatebradine is a bradycardic agent with a selective effect on the pacemaker current in the sinus node. The effect of such drugs on heart rate variability is not known. Thirty-six patients without structural heart disease were randomly assigned to receive 10 mg of zatebradine i.v. (n = 24) or isotonic saline (n = 12). Heart rate variability (HRV) was recorded as power in the very low frequency (VLF, 0.003-0.040 Hz), low frequency (LF, 0.040-0.150 Hz), and high frequency (HF, 0.150-0.400 Hz) spectral bands as well as total power (TP, 0.003-0.400 Hz) during 5-min ECG acquisitions at baseline, 30, and 60 min following the start of the infusion. No change in heart rate variability was detected in the control group. Zatebradine significantly reduced heart rate variability at 60 min in all frequency bands: VLF (-12 ± 4%, p < 0.001), LF (-19 ± 4%, p < 0.001), and HF (-26 ± 5%, p < 0.001). The reduction in HRV following zatebradine is due to depression of sinus node response to all external stimuli and underscores the need for documentation of normal sinus node function in HRV research.Key words: zatebradine, sinus node, heart rate variability, HRV, autonomic nervous system.


2020 ◽  
Vol 45 (10) ◽  
pp. 1138-1144 ◽  
Author(s):  
Robert F. Bentley ◽  
Emily Vecchiarelli ◽  
Laura Banks ◽  
Patric E.O. Gonçalves ◽  
Scott G. Thomas ◽  
...  

The purpose of this study was to determine potential adverse cardiac effects of chronic endurance training by comparing sympathovagal modulation via heart rate variability (HRV) and heart rate recovery (HRR) in middle-aged endurance athletes (EA) and physically active individuals (PA) following maximal exercise. Thirty-six (age, 53 ± 5 years) EA and 19 (age, 56 ± 5 years) PA were recruited to complete a 2-week exercise diary and graded exercise to exhaustion. Time domain and power spectral HRV analyses were completed on recorded R-R intervals. EA had a greater HRR slope following exercise (95% confidence interval, 0.0134–0.0138 vs. 0.0101–0.0104 beats/s; p < 0.001). While EA had greater HRR at 1–5 min after exercise (all p < 0.01), PA and EA did not differ when expressed as a percentage of baseline heart rate (130 ± 19 vs. 139 ± 19; p = 0.2). Root mean square of successive differences in R-R intervals (rest and immediately after exercise) were elevated in EA (p < 0.05). Low-frequency (LF) and high-frequency (HF) spectral components were nonsignificantly elevated after exercise (p = 0.045–0.147) in EA while LF/HF was not different (p = 0.529–0.986). This data suggests greater HRR in EA may arise in part due to a lower resting HR. While nonsignificant elevations in HF and LF in EA produces a LF/HF similar to PA, absolute spectral component modulation differed. These observations require further exploration. Novelty Acute effects of exercise on HRV in EA compared with a relevant control group, PA, are unknown. EA had greater HRR and nonsignificant elevations in LF and HF compared with PA, yet LF/HF was not different. Future work should explore the implications of this observation.


Author(s):  
SARIKA KS ◽  
VANDANA BALAKRISHNAN ◽  
HARISH KUMAR ◽  
ANAND KUMAR ◽  
KR SUNDARAM

Objective: This study aims in understanding the effects of Integrated Amrita Meditation (IAM), a type of mindfulness meditation, on the autonomic balance of type 2 diabetic patients through assessment of heart rate variability (HRV). Methods: After the initial screening of 30 type 2 diabetic subjects, 10 type 2 diabetic subjects between the age group of 30 and 65 years were randomized into two groups, diabetic test (n=5) and diabetic control group (n=5). Diabetic test group practiced IAM technique under the guidance of a trained practitioner. Both the groups continued the same dietary pattern and medications during the 6-month study period. HRV was taken for all subjects at baseline and after 6 months. In our study, we have focused on the power spectral analysis of HRV which include normalized units of high frequency (nHF), low frequency (nLF), and low frequency-high frequency ratio (LF/HF ratio). Results: Mean percentage change in nHF, nLF, and LFHF ratio showed significant changes in between-group comparison (p<0.05). Normalized units of HF increased (p=0.049) while LF (p=0.036) and LFHF ratio (p=0.024) decreased significantly within test group after 6 months of IAM practice suggesting the potential of IAM in improving the parasympathetic tone, thereby tuning the mind and body to calm down during stress. Conclusion: Our study has shown demonstrable improvement in autonomic function which reflects reduced stress after the practice of IAM in diabetic patients.


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