Heart rate recovery at 1st min after graded exercise an indicator of parasympathetic function in healthy obese young adults

Background: Heart rate recovery at 1st min (HRR 1 min) after graded treadmill exercise (GTX) is a predictor of parasympathetic function. Impaired HRR 1 min and obesity are strong predictors of metabolic syndrome and cardiovascular disorders. This study is done to asses HRR 1 min on apparently healthy obese young adults with body mass index (BMI) ?30, without any other metabolic syndrome components. Aims and Objectives: The objective of this study was to assess the parasympathetic function by estimating HRR 1 min after exercise in apparently healthy obese young adults of 18–30 years of age without any metabolic syndrome components and is compared with age- and gender-matched controls with normal BMI. Materials and Methods: Fifty obese young adults with BMI ?30 without any other metabolic syndrome component and 50 age- and gender-matched controls with BMI ?24.9 were selected and subjected to GTX according to modified Bruce protocol. Maximum heart rate reached during exercise (HRmax) and heart rate at 1st min of recovery phase (HR1min) were recorded. HRR 1 min was calculated as HRmax-HR1min and was analyzed. Results: This study showed significantly attenuated HRR 1 min in obese young adults compared to age- and gender-matched controls (mean 24.02 ± 8.87 vs. 42.42 ± 5.3, P < 0.001). Conclusion: HRR 1 min was significantly decreased in obese young adults, indicating attenuated parasympathetic function, who are at higher risk of developing chronic cardiovascular and other metabolic disorders.

Neuromodulação Vagal Auricular e sua Aplicabilidade em Pacientes com Insuficiência Cardíaca e Fração de Ejeção Reduzida / Auricular Vagal Neuromodulation and its Application in Patients with Heart Failure and Reduced Ejection Fraction

Resumo Fundamento O desequilíbrio do sistema nervoso autônomo (SNA) na insuficiência cardíaca (IC) cria um ciclo vicioso, o excesso de atividade simpática e a diminuição da atividade vagal contribuindo para a piora da IC. A estimulação elétrica transcutânea de baixa intensidade do ramo auricular do nervo vago (taVNS) é bem tolerada e abre novas possibilidades terapêuticas. Objetivos Gerar hipótese da aplicabilidade e benefício da taVNS na IC através da comparação intergrupos de parâmetros ecocardiográficos, teste de caminhada de 6 min, variabilidade da frequência cardíaca pelo Holter (SDNN e rMSSD), questionário de qualidade de vida de Minnesota e classe funcional pela New York Heart Association. Métodos Estudo clínico prospectivo, duplo cego, randomizado com metodologia sham, unicêntrico. Avaliados 43 pacientes e alocados em 2 grupos: o Grupo 1 recebeu taVNS (frequências 2/15 Hz) e Grupo 2 recebeu sham. Nas comparações, valores de p<0,05 foram considerados significativos. Resultados Na fase pós-intervenção, observou-se que o Grupo 1 se manteve com melhor rMSSD (31 x 21; p = 0,046) e atingiu melhor SDNN (110 vs. 84, p = 0,033). Ao compararmos os parâmetros intragrupos, antes e após intervenção, observou-se que todos melhoraram significativamente no grupo 1 e não houve diferenças no grupo 2. Conclusão A taVNS é uma intervenção segura, de fácil execução e que sugere provável benefício na IC pela melhora na variabilidade da frequência cardíaca, o que indica melhor equilíbrio autonômico. Novos estudos com maior número de pacientes são necessários para responder às questões levantadas por esse estudo.

Abstract Background The autonomic nervous system (ANS) imbalance in heart failure (HF) creates a vicious cycle, excess sympathetic activity, and decreased vagal activity contributing to the worsening of HF. Low-intensity transcutaneous electrical stimulation of the auricular branch of the vagus nerve (taVNS) is well tolerated and opens new therapeutic possibilities. Objectives To hypothesize the applicability and benefit of taVNS in HF through intergroup comparison of echocardiography parameters, 6-minute walk test, Holter heart rate variability (SDNN and rMSSD), Minnesota quality of life questionnaire, and functional class by the New York Heart Association. In comparisons, p values <0.05 were considered significant. Methods Prospective, double-blind, randomized clinical study with sham methodology, unicentric. Forty-three patients were evaluated and divided into 2 groups: Group 1 received taVNS (frequencies 2/15 Hz), and Group 2 received sham. In comparisons, p values <0.05 were considered significant. Results In the post-intervention phase, it was observed that Group 1 had better rMSSD (31 x 21; p = 0.046) and achieved better SDNN (110 vs. 84, p = 0.033). When comparing intragroup parameters before and after the intervention, it was observed that all of them improved significantly in group 1, and there were no differences in group 2. Conclusion taVNS is a safe to perform and easy intervention and suggests a probable benefit in HF by improving heart rate variability, which indicates better autonomic balance. New studies with more patients are needed to answer the questions raised by this study.

Comparison of the autonomic nervous system dysfunction between different chronic spine disorders: neck pain versus low back pain

SUMMARY OBJECTIVE: This study aims to compare heart rate variability (HRV) between patients with chronic neck pain and patients with chronic low back pain and to correlate the chronic pain variables with heart rate variability indices. METHODS: This is a cross-sectional study. We divided the sample into two groups: neck pain (n=30) and low back pain (n=30). We used the Numeric Pain Rating Scale, Neck Disability Index, Roland-Morris Disability Questionnaire, Pain-Related Catastrophizing Thoughts Scale, Tampa Scale of Kinesiophobia, and Pain Self-Efficacy Questionnaire. For heart rate variability analysis, we used the following indices: mean RR, standard deviation of all RR intervals, mean heart rate, root mean square differences of successive RR intervals, triangular index, triangular interpolation of the interval histogram, low-frequency band in arbitrary units and in absolute values, high-frequency band in arbitrary units and in absolute values, standard deviation of the instantaneous beat-to-beat variability (standard deviation 1), long-term standard deviation of continuous RR intervals (standard deviation 2), and Stress Index. We used Student's t-test for comparisons and Spearman's coefficient for correlations. RESULTS: We observe insignificant values in the differences between the groups. Disability and self-efficacy were correlated with heart rate variability only in patients with chronic neck pain, whereas catastrophizing and kinesiophobia showed greater correlations with heart rate variability in patients with chronic low back pain. CONCLUSIONS: Autonomic dysfunction of individuals with chronic neck pain, when compared to patients with chronic low back pain, does present insignificant differences.

Heart rate and cardiac autonomic responses to concomitant deep breathing, hand grip exercise, and circulatory occlusion in healthy young adult men and women

BACKGROUND: Deep breathing (DB) and handgrip (HG) exercise -with and without circulatory occlusion (OC) in muscle-, have been shown to have beneficial effects on cardiovascular function; however, the combination of these maneuvers on heart rate (HR) and cardiac sympathovagal balance have not been previously investigated. Therefore, the aim of the present study was to evaluate the effect of simultaneous DB, HG, and OC maneuvers on the sympathovagal balance in healthy women and men subjects. METHODS AND RESULTS: Electrocardiogram and ventilation were measured in 20 healthy subjects (Women: n = 10; age = 27 ± 4 years; weight = 67.1 ± 8.4 kg; and height = 1.6 ± 0.1 m. Men: n = 10; age = 27 ± 3 years; weight = 77.5 ± 10.1 kg; and height = 1.7 ± 0.1 m) at baseline and during DB, DB + HG, or DB + HG + OC protocols. Heart rate (HR) and respiratory rate were continuously recorded, and spectral analysis of heart rate variability (HRV) were calculated to indirectly estimate cardiac autonomic function. Men and women showed similar HR responses to DB, DB + HG and DB + HG + OC. Men exhibited a significant HR decrease following DB + HG + OC protocol which was accompanied by an improvement in cardiac autonomic control evidenced by spectral changes in HRV towards parasympathetic predominance (HRV High frequency: 83.95 ± 1.45 vs. 81.87 ± 1.50 n.u., DB + HG + OC vs. base-line; p < 0.05). In women, there was a marked decrease in HR after completion of both DB + HG and DB + HG + OC tests which was accompanied by a significant increase in cardiac vagal tone (HRV High frequency: 85.29 ± 1.19 vs. 77.93 ± 0.92 n.u., DB + HG vs. baseline; p < 0.05). No adverse effects or discomfort were reported by men or women during experimental procedures. Independent of sex, combination of DB, HG, and OC was tolerable and resulted in decreases in resting HR and elevations in cardiac parasympathetic tone. CONCLUSIONS: These data indicate that combined DB, HG and OC are effective in altering cardiac sympathovagal balance and reducing resting HR in healthy men and women.

A Study of Assessment of Cardiac Autonomic Functions after Yogasana and Pranayama

Introduction: Modern lifestyle, busy work schedule, lackof exercise, more expectancy generates stress in human life.Stress is a crucial factor in origin of diseases. Stress leads toautonomic imbalance. Yoga has very positive effects on stress.Yoga is now widely used for prevention and treatment ofvarious disorders and to achieve the physical, Physiological,Psychological, spiritual and social well being of the person.So this study is planned to see the effects of yoga on healthysubjects as an important preventive measure to remain awayfrom diseases. The present study was undertaken to showthe various effects of selective yogasana and pranayama oncardiac autonomic functions in healthy subjects between agegroup 31 to 60 years.Material and Methods: The subjects fulfilling the inclusioncriteria underwent the yogasana and pranayama sessions.Anthropometric data was collected. The cardiovascular statusof 45 healthy subjects was assessed by cardiac autonomicfunction tests before the start of and after 3 months ofyogasanaand pranayama practice daily for one hour. Theinstruments Diabetic Risk Profiler by Genesis HealthcareSystem Hydrabad, Handgrip dynamometer, digital bloodpressure apparatus, cold water tub were used. The testsconducted were resting heart rate, resting blood pressure, deepbreathing test(E/I ratio), orthostatic heart rate response (30/15ratio), valsalva ratio, sustained handgrip test, cold pressor testand blood pressure response to standing.Results: After yogasana and pranayama for three monthssignificant reduction in resting HR, SBP and DBP were found.Mean resting heart rate (HR) was decreased from 77.04/minto 71.38/min, mean SBP from 121mmHg to 117.51 mmHgand mean DBP from 83.42mmHg to 79.91mmHg. There wassignificant increase in parasympathetic reactivity parameterslike orthostatic HRR from 1.12 to 1.50, Deep breathing from1.20 to 1.52 and valsalva ratio from 1.24 to 1.67. There wassignificant decrease in sympathetic reactivity variables likesustained HGT Difference of diastolic BP (∆DBP) from 11.40to 7.73 mmHg, cold pressor test ∆DBP 11.67 to 7.71mmHgand BP response to standing Difference of systolic BP (∆SBP)from 10.71 to7.64 mmHg. There were no statistical significantchange observed in anthropometric parameters like body massindex (BMI) from 24.12 to 23.28 and waist hip ratio(WHR)from 0.87 to 0.85.Conclusion: It can be concluded that yogasana and pranayamahas beneficial effects on cardiac autonomic activities andreactivity. This lifestyle should be followed regularly as apreventive measure by the persons with cardiac diseasesto get relief and also healthy persons to remain away fromcardiovascular problems.

Introduction of Application of Gini Coefficient to Heart Rate Variability Spectrum for Mental Stress Evaluation / Introdução da Aplicação do Coeficiente de Gini ao Espectro de Variabilidade da Frequência Cardíaca para Avaliação do Estresse Mental

Abstract Background: The Gini coefficient is a statistical tool generally used by economists to quantify income inequality. However, it can be applied to any kind of data with unequal distribution, including heart rate variability (HRV). Objectives: To assess the application of the Gini coefficient to measure inequality in power spectral density of RR intervals, and to use this application as a psychophysiological indicator of mental stress. Methods: Thirteen healthy subjects (19 ± 1.5 years) participated in this study, and their RR intervals were obtained by electrocardiogram during rest (five minutes) and during mental stress (arithmetic challenge; five minutes). These RR intervals were used to obtain the estimates of power spectral densities (PSD). The limits for the PSD bands were defined from 0.15 to 0.40 Hz for high frequency band (HF), from 0.04 to 0.15 Hz for low frequency band (LF), from 0.04 to 0.085 Hz for first low frequency sub-band (LF1) and from 0.085 to 0.15 Hz for second low frequency sub-band (LF2). The spectral Gini coefficient (SpG) was proposed to measure the inequality in the power distribution of the RR intervals in each of above-mentioned HRV bands. SpG from each band was compared with its respective traditional index of HRV during the conditions of rest and mental stress. All the differences were considered statistically significant for p < 0.05. Results: There was a significant decrease in HF power (p = 0.046), as well as significant increases in heart rate (p = 0.004), LF power (p = 0.033), LF2 power (p = 0.019) and LF/HF (p = 0.002) during mental stress. There was also a significant increase in SpG(LF) (p = 0.009) and SpG(LF2) (p = 0.033) during mental stress. Coefficient of variation showed SpG has more homogeneity compared to the traditional index of HRV during mental stress. Conclusions: This pilot study suggested that spectral inequality of Heart Rate Variability analyzed using the Gini coefficient seems to be an independent and homogeneous psychophysiological indicator of mental stress. Also, HR, LF/HF, SpG(LF) of HRV are possibly important, reliable and valid indicators of mental stress.

Resumo Fundamento: O coeficiente de Gini é um instrumento estatístico geralmente usado por economistas para quantificar a desigualdade de renda. No entanto, ele pode ser aplicado a qualquer tipo de dados com distribuição desigual, incluindo a variabilidade da frequência cardíaca (VFC). Objetivos: Avaliar a aplicação do coeficiente de Gini para medir a desigualdade na densidade espectral de potência de intervalos RR, e usar esta aplicação como um indicador psicofisiológico do estresse mental. Métodos: Treze indivíduos saudáveis (19 ± 1,5 anos) participaram deste estudo, e seus intervalos RR foram obtidos por eletrocardiograma durante repouso (cinco minutos) e durante estresse mental (desafio aritmético; cinco minutos). Esses intervalos RR foram utilizados para obter as estimativas de densidades espectrais de potência (PSD). Os limites para as bandas PSD foram definidos de 0,15 a 0,40 Hz para banda de alta frequência (HF), de 0,04 a 0,15 Hz para banda de baixa frequência (LF), de 0,04 a 0,085 Hz para a primeira sub-banda de baixa frequência (LF1) e de 0,085 a 0,15 Hz para a segunda sub-banda de baixa frequência (LF2). O coeficiente de Gini espectral (SpG) foi proposto para medir a desigualdade na distribuição de potência dos intervalos RR em cada uma das bandas de VFC mencionadas acima. O SpG de cada banda foi comparado com seu respectivo índice tradicional de VFC durante as condições de repouso e de estresse mental. Todas as diferenças foram consideradas estatisticamente significativas para p < 0,05. Resultados: Houve uma diminuição significativa no poder de FC (p=0,046), bem como aumentos significativos na frequência cardíaca (p = 0,004), potência da LF (p = 0,033), potência da LF2 (p = 0,019) e LF/HF (p = 0,002) durante estresse mental. Houve também um aumento significativo de SpG(LF) (p = 0,009) e SpG(LF2) (p = 0,033) durante estresse mental. O coeficiente de variação mostrou que o SpG tem mais homogeneidade em comparação com o índice tradicional de VFC durante o estresse mental. Conclusões: Este estudo piloto sugeriu que a desigualdade espectral da VFC analisada pelo coeficiente de Gini parece ser um indicador psicofisiológico independente e homogêneo de estresse mental. Além disso, FC, LF/HF, SpG(LF) da VFC são possivelmente indicadores importantes, confiáveis e válidos de estresse mental.

A pilot study on the role of autonomic function testing in predicting hypotension in patients undergoing cesarean section under spinal anesthesia

BACKGROUND: Maternal hypotension is a common complication during obstetric spinal anesthesia. This study was conducted to investigate the role of autonomic function testing in predicting maternal hypotension during spinal anesthesia induced to conduct Cesarean sections (C-section). METHODS: This study was conducted on 32 parturients undergoing C-section under spinal anesthesia. Sympathetic function tests included measuring diastolic blood pressure changes in response to hand gripping and systolic blood pressure changes response to moving from a supine to a standing position. Sympathetic dysfunction is said to exist when there are abnormal responses to both sympathetic function tests. Parasympathetic function tests included measuring heart rate responses to deep breathing and heart rate responses to moving from a supine to a standing position. Parasympathetic dysfunction is said to exist when there are abnormal responses to both parasympathetic function tests. After the onset of spinal anesthesia, blood pressure was measured every minute until childbirth. RESULTS: Hypotension occurred in 22 of the 32 parturients. There was no correlation between sympathetic dysfunction and hypotension incidence, but 12 of the 12 (100%) of the positive group and 10 of the 20 (50%) of the negative group experiencing parasympathetic dysfunction, respectively, experienced hypotension with a significant difference of P = 0.004. The group experiencing parasympathetic dysfunction had statistically significantly higher phenylephrine requirements were also greater in the parasympathetic dysfunction positive group (P < 0.003). CONCLUSIONS: This study's findings suggested that the parasympathetic function tests may be useful methods for predicting the incidence of maternal hypotension during spinal anesthesia induced for C-section.

Consideration of a New Category of Patients for Whom Ryokeijutsukanto is Effective at a Different Stage Then was Previously Reported / 日本東洋医学雑誌

Ryokeijutsukanto consists of four crude drugs, Hoelen, Cinnamonmi Cortex, Atractylodis Rhizoma, and Glycyrrhizae Radix. In Kampo medicine, it is used for the yang stage, fluid disturbances, and qi counterflow. It is also used for orthostatic disturbance, which does not change smoothly from parasympathetic nerve dominance to sympathetic nerve dominance. This time, we report that ryokeijutsukanto is also effective for disturbance with function regulation of autonomic nervous system. Case 1: a patient who had headache after exercise and working. Case 2: a patient who had dizziness and cold sweat that appeared in the evening. Case 3: a patient who had headache after working or on holidays. In these cases, ryokeijutsukanto was effective for symptoms that appeared when the patient could not change smoothly from sympathetic nerve dominance to parasympathetic nerve dominance. Furthermore, we found that ryokeijutsukanto was effective, even if there was no sign of fluid disturbance in conjunction with the yang stage and qi counterflow. We identified a new category of patients for whom ryokeijutsukanto is effective.

Baroreflex Control of Heart Rate in Mice Overexpressing Human SOD1: Functional Changes in Central and Vagal Efferent Components / 神经科学通报·英文版

Excessive reactive oxygen species (ROS) (such as the superoxide radical) are commonly associated with cardiac autonomic dysfunctions. Though superoxide dismutase 1 (SOD1) overexpression may protect against ROS damage to the autonomic nervous system, superoxide radical reduction may change normal physiological functions. Previously, we demonstrated that human SOD1 (hSOD1) overexpression does not change baroreflex bradycardia and tachycardia but rather increases aortic depressor nerve activity in response to arterial pressure changes in C57B6SJL-Tg (SOD1)2 Gur/J mice. Since the baroreflex arc includes afferent, central, and efferent components, the objective of this study was to determine whether hSOD1 overexpression alters the central and vagal efferent mediation of heart rate (HR) responses. Our data indicate that SOD1 overexpression decreased the HR responses to vagal efferent nerve stimulation but did not change the HR responses to aortic depressor nerve (ADN) stimulation. Along with the previous study, we suggest that SOD1 overexpression preserves normal baroreflex function but may differentially alter the functions of the ADN, vagal efferents, and central components. While SOD1 overexpression likely enhanced ADN function and the central mediation of bradycardia, it decreased vagal efferent control of HR.

Is a short-stage protocol during an incremental exercise test reliable for heart rate variability threshold analysis?

Aim: Heart rate variability threshold (HRVT) is a valid method to determine parasympathetic depression during an incremental exercise test (IET). However, HRVT is usually assessed using the last 60s of each 180s stage of an IET, resulting in longer and demotivating tests. This study aimed to evaluate the agreement of HRVT analysis adopting the first and second minute of R-R interval (iRR) segment comparatively to a standard third-minute segment obtained at each 3-min stage on IET. Methods: Seventeen young male subjects (22.2 ± 3.1 years; 23.4 ± 2.3 kg/m2) underwent IET on a cycle ergometer. HRVT was considered the load corresponding to the point of stabilization of the SD1 index (HRVTV), or the first load with SD1 value < 3ms (HRVT<3), both assessed by the 1st (HRVT1V, HRVT1<3), 2nd (HRVT2V, HRVT2<3) and standard 3rd (HRVT3V, HRVT3<3) 60s iRR segment analyzed at each stage of IET. Agreement and reliability were assessed by the Bland-Altman analysis and the intraclass correlation coefficient (ICC), respectively. Results: High reliability and non-significant bias were observed considering HRVT1V vs HRVT3V (ICC = 0.92; p = 0.18) or HRVT2V vs HRVT3V (ICC = 0.94; p = 0.99). However, lower reliability was observed for HRVT1<3 vs HRVT3<3 (ICC = 0.79; p = 0.75) and for HRVT2<3 vs HRVT3<3 (ICC = 0.91; p = 0.33). Conclusion: HRVT can be similarly assessed by the 1st, 2nd or 3rd 60 seconds iRR segment, mainly when assessed by a visual method.(AU)

Impact of heart rate on reproducibility of heart rate variability analysis in the supine and standing positions in healthy men

OBJECTIVE: The reliability of heart rate variability (HRV) analysis is not yet fully understood, especially considering different body positions and the mathematical influence of heart rate. The aim of this study was to evaluate the reliability of HRV in supine and standing positions, with and without mathematical adjustment of HRV by the average R-R interval (iRR). METHODS: We evaluated 37 young males (23.1±4 years; 25.1±3 kg/m2). A 5-min segment of the iRR was collected in the supine and standing positions on three occasions separated by 48-hour intervals. Absolute and relative reliability of temporal and spectral indices were assessed by the coefficient of variation (CV) and the intraclass correlation coefficient (ICC), respectively. RESULTS: We did not observe differences in HRV indices in the three occasions in the supine or standing position (p>0.05). Moderate to good reproducibility was observed for temporal and spectral indices of HRV in the supine position (ICC: 0.65-0.89; CV: 0.9-19.8). In the orthostatic position, low to good reproducibility was observed (ICC: 0.35-0.89; CV: 1.1-34.8), with higher ICCs for temporal indices. After mathematical adjustment, only a small modification in HRV reliability was observed in both positions. CONCLUSIONS: In young adult males, the mathematical adjustment of HRV by the average iRR led to a nonsignificant effect on HRV reliability. Additionally, HRV reliability is dependent on body position and the index analyzed. Promising measures in both supine and standing positions include r-MSSD and the HF band (parasympathetic indices).

Cardiac vagal index varies according to field position in male elite football players / índice vagal cardíaco varia com a posição em campo de jogadores da elite do futebol

BACKGROUND: Cardiac vagal index (CVI) is supposedly higher in athletes and may differ between sports and/or between field positions. OBJECTIVE: To compare CVI: a) between elite football players vs. non-athletes and b) according to five football positions. METHOD: 242 football players of the first Brazilian/Angolan division were divided in five positions (N): goalkeepers (17), defenders (44), wingers (34), midfielders (87) and forwarders (60) and compared with 303 age-matched healthy non-athletes. CVI was estimated from a 4-second exercise test by quantifying the ratio of two cardiac cycle durations, before and at the end of a fast unloaded cycling exercise. RESULTS: Football players had resting and maximal heart rates of, respectively, 59 and 190 bpm and measured VO2max of 62.2 mL/(kg.min). Players and non-athletes showed similar CVI results (median-[P25-P75]) - 1.63-[1.46-1.84] vs 1.61-[1.41-1.81] (p = 0.22). Wingers tended to have a higher CVI (1.84-[1.60-1.99]), especially when compared to defenders (1.53-[1.41-1.72] (p = 0.01). There was a modest non-physiologically relevant association between VO2max and CVI (r = 0.15). CONCLUSIONS: Football players did not differ from non-athletes in CVI; however, among players, wingers were more often vagotonic, which may represent a hemodynamic advantage for match situations, where rapid heart rate transitions and faster oxygen delivery to muscles are required.

FUNDAMENTOS: O índice vagal cardíaco (IVC) é supostamente maior em atletas e pode diferir entre esportes e dentro do mesmo esporte. OBJETIVO: Comparar o IVC: a) entre futebolistas e não atletas e b) de acordo com cinco posições do futebol. MÉTODO: 242 jogadores da primeira divisão brasileira/angolana foram divididos em cinco posições (N): goleiros (17), zagueiros (44), laterais (34), meio-campistas (87) e atacantes (60) e comparados com 303 não-atletas saudáveis da mesma idade. IVC foi estimado a partir do teste de exercício de 4 segundos, quantificando a relação entre as durações de dois ciclos cardíacos - antes e ao final de uma pedalada rápida e sem carga RESULTADOS: As frequências cardíacas de repouso e máxima dos futebolistas foram, respectivamente, 59 e 190 bpm e o VO2max de 62,2 mL/(kg.min). Futebolistas e não-atletas mostraram resultados semelhantes de IVC (mediana- [P25-P75]) - 1,63- [1,46-1,84] vs 1,61- [1,41-1,81] (p = 0,22). Os laterais tenderam a ter maior IVC (1,84- [1,60-1,99]), especialmente quando comparados aos defensores (1,53- [1,41-1,72] (p = 0,01). Houve uma modesta associação fisiologicamente irrelevante entre VO2max e IVC (r = 0,15). CONCLUSÕES: jogadores da elite do futebol não diferem de não-atletas em IVC; entretanto, entre eles, os alas se mostraram mais frequentemente vagotônicos, o que pode representar uma vantagem hemodinâmica para situações de jogo, onde são necessárias transições rápidas da frequência cardíaca e um aporte mais rápido de oxigênio para os músculos ativos.

EFEITO DE DIFERENTES PROTOCOLOS DE RECUPERAÇÃO SOBRE A FUNÇÃO AUTONÔMICA CARDÍACA / EFFECT OF DIFFERENT RECOVERY PROTOCOLS ON THE CARDIAC AUTONOMIC FUNCTION / EFECTO DE DIFERENTES PROTOCOLOS DE RECUPERACIÓN SOBRE LA FUNCIÓN AUTONÓMICA CARDIACA

RESUMO Introdução: A avaliação da função autonômica cardíaca (FAC) após o teste de esforço (TE) é considerada um preditor poderoso e independente de risco cardiovascular. É escasso o conhecimento da influência de diferentes protocolos de recuperação sobre a FAC após TE em esteira rolante com os voluntários na posição ortostática. Objetivo: Comparar a reativação vagal e o grau de modulação global da FAC em dois diferentes protocolos de recuperação, passiva (RP) e ativa (RA), imediatamente após TE submáximo em esteira rolante. Métodos: Foram avaliados 24 homens fisicamente ativos com idade (média ± DP) de 27,2 ± 4,4 anos e IMC 24,8 ± 1,8 kg/m2. A ordem dos protocolos de recuperação foi definida de forma aleatória. Os testes foram realizados com intervalo de sete dias. Ambas as recuperações foram realizadas na posição ortostática durante cinco minutos, imediatamente após TE. Os índices temporais da variabilidade da frequência cardíaca foram utilizados para avaliar a reativação vagal e o grau de modulação global de FAC, rMSSD e SDNN, respectivamente, na RP e RA. Após análise da distribuição dos dados, utilizaram-se os testes de Mann-Whitney e de Friedman com post-hoc de Dum, no nível de significância de p ≤ 0,05. Resultados: Verificou-se maior reativação vagal no primeiro minuto de recuperação na RP comparativamente a RA [4,1 (4,9-3,4) ms vs. 3,4 (4,0-2,9) ms, p = 0,03] e maior grau de modulação global da FAC do terceiro ao quinto minuto e tendência a diferença significativa no segundo minuto de RP comparativamente a RA (p = 0,09-0,005). Conclusão: Os achados demonstram que o mínimo esforço físico, como caminhar lentamente sobre a esteira rolante, diminuiu a reativação vagal e o grau de modulação global da FAC após o TE submáximo em homens fisicamente ativos.

ABSTRACT Introduction: The evaluation of cardiac autonomic function (CAF) after stress test (ST) is considered a powerful and independent predictor of cardiovascular risk. The knowledge about the influence of different recovery protocols on CAF after ST on treadmill with volunteers in standing position is scarce. Objective: To compare the vagal reactivation and the degree of global CAF modulation in two different recovery protocols, passive (PR) vs. active (AR) immediately after submaximal ST in treadmill. Methods: We evaluated 24 physically active males, aged (mean ± SD) 27.2 ± 4.4 years and BMI 24.8 ± 1.8 kg/m2. The order of the recovery protocol was set at random. The tests were performed in 7-day intervals. Both recovery protocols were performed in standing position for 5 minutes, immediately after ST. The time indices of heart rate variability were used to assess the vagal reactivation and the overall degree of CAF, rMSSD, and SDNN, respectively, in PR and AR. After analysis of the data distribution, the Mann-Whitney and Friedman tests with Dum post-hoc were used at a significance level of p ≤ 0.05. Results: We observed a higher vagal reactivation at first minute of the PR compared to AR [4.1 (4.9-3.4) ms vs. 3.4 (4.0-2.9) ms, p = 0.03], and a higher degree of global CAF modulation from the third to the fifth minute and a tendency to significant difference in the second minute of PR compared to AR (p = 0.09−0.005). Conclusion: The findings demonstrate that minimum physical effort, such as walking slowly on a treadmill, decreased the vagal reactivation and the overall modulation degree of CAF after a submaximal ST in physically active men.

RESUMEN Introducción: La evaluación de la función autonómica cardíaca (FAC) después de la prueba de esfuerzo (PE) se considera un predictor potente e independiente del riesgo cardiovascular. Es escaso el conocimiento de la influencia de los diferentes protocolos de recuperación sobre la FAC después de la PE en la cinta rodante con voluntarios en la posición de pie. Objetivo: Comparar la reactivación vagal y el grado de la modulación general de la FAC en dos diferentes protocolos de recuperación, pasiva (RP) vs. activa (RA) inmediatamente después de la PE submáxima en la cinta rodante. Métodos: Se evaluaron 24 hombres físicamente activos con edades (promedio ± DE) de 27,2 ± 4,4 años y IMC de 24,8 ± 1,8 kg/m2. El orden de los protocolos de recuperación se definió al azar. Las pruebas se realizaron en un intervalo de siete días. Ambas recuperaciones se realizaron en la posición de pie durante cinco minutos inmediatamente después de la PE. Los índices temporales de la variabilidad de la frecuencia cardiaca fueron utilizados para evaluar la reactivación vagal y el grado de modulación general de la FAC, rMSSD y SDNN, respectivamente, en RP y RA. Después del análisis de la distribución de los datos, se utilizaron la prueba de Mann-Whitney y la de Friedman con post-hoc de Dum, a un nivel de significación de p ≤ 0,05. Resultados: Se observó una mayor reactivación vagal en el primer minuto de la PR comparada a la RA [4,1 (4,9-3,4) ms vs. 3,4 (4,0-2,9) ms, p = 0,03] y un mayor grado de modulación general de la FAC del tercer al quinto minuto y una tendencia a la diferencia estadística en el segundo minuto de RP comparada a RA (p = 0,09-0,005). Conclusión: Los resultados muestran que el esfuerzo físico mínimo, como caminar lentamente sobre la cinta rodante, disminuyó la reactivación vagal y el grado de modulación general de la FAC después de la PE submáxima en hombres físicamente activos.

Anatomy and Physiology of the Autonomic Nervous System / 대한평형의학회지

The autonomic nervous system (ANS) integrates the function of the internal organs for the homeostasis against various external environmental changes. The efferent components of the ANS are regulated by sensory signals arising from the viscera as well as non-visceral organs. The central neural networks that integrate these sensory signals and modify visceral motor output are complex, and synaptic reflexes formed in the brainstem and spinal cord integrate behavioral responses and visceral responses through the central neural networks. A detailed understanding of the neural network presented above may explain the role of the vestibular system on the homeostasis more extensively.

Correlation between sleep quality and parasympathetic intensity at nighttime / 中华神经科杂志

Objective To clarify the effect of cardio pulmonary coupling (CPC) technology on sleep quality and the effect of Shichen-based physiological function index analysis on sleep health assessment.Methods CPC and Shichen-based physiological function index were used to evaluate the sleep quality of 242 volunteers from 9:00 pm to 9:00 am for 12 hours.Based on CPC technology score,volunteers wree seperated to three sleep quality groups (scoring 85-100 in 63 volunteers,scoring 60-84 in 80 volunteers,scoring ＜ 60 in 99 volunteers).The results of sleep quality and parasympathetic intensity over the whole nighttime and the different time period of each sleep quality group were compared and the correlation analysis was done.Results The whole nighttime sleep quality test showed that there was significant difference (t =-12.754-19.030,all P ＜ 0.01) in the time to the stable sleep ratio (52.78％ ± 10.32％,43.99％ ± 14.48,20.95％ ± 10.41％),the disturbed sleep ratio (25.65％ ± 7.81％,34.18％ ± 12.71％,53.65％ ± 14.81％),and the apnea-hypopnea index (2.79 ±2.95,7.93 ± 6.61,23.94 ± 16.09)in the different sleep quality groups.The Shichen-based sleep quality test showed that there was significant difference among the stable sleep ratio,the disturbed sleep ratio during the 23:00 pm to 5:00 am period in the different sleep quality groups.There existed significant difference with parasympathetic intensity in the different sleep quality groups.There was positive correlation between the parasympathetic intensity and the stable sleep ratio in the same sleep quality group (r =0.508,P ＜ 0.05).Conclusions CPC evaluation can commendably distinguish and evaluate different sleep quality groups on the whole night sleep.The Shichen-based physiological function index can not only distinguish the sleep quality,but also evaluate the multiple physiological function,the parasympathetic intensity between different sleep quality groups during different sleep periods.Thus they can be widely used to assess the sleep quality.

Heart Rate Variability Among Children With Acquired Brain Injury

OBJECTIVE: To find evidence of autonomic imbalance and present the heart rate variability (HRV) parameters that reflect the severity of paroxysmal sympathetic hyperactivity (PSH) in children with acquired brain injury (ABI). METHODS: Thirteen children with ABI were enrolled and age- and sex-matched children with cerebral palsy were selected as the control group (n=13). The following HRV parameters were calculated: time-domain indices including the mean heart rate, standard deviation of all average R-R intervals (SDNN), root mean square of the successive differences (RMSSD), physical stress index (PSI), approximate entropy (ApEn); successive R-R interval difference (SRD), and frequency domain indices including total power (TP), high frequency (HF), low frequency (LF), normalized HF, normalized LF, and LF/HF ratio. RESULTS: There were significant differences between the ABI and control groups in the mean heart rate, RMSSD, PSI and all indices of the frequency domain analysis. The mean heart rate, PSI, normalized LF, and LF/HF ratio increased in the ABI group. The presence of PSH symptoms in the ABI group demonstrated a statistically significant decline of the SDNN, TP, ln TP. CONCLUSION: The differences in the HRV parameters and presence of PSH symptoms are noted among ABI children compared to an age- and sex-matched control group with cerebral palsy. Within the ABI group, the presence of PSH symptoms influenced the parameters of HRV such as SDNN, TP and ln TP.

Cardiac arrest attributable to dysfunction of the autonomic nervous system after traumatic cervical spinal cord injury / 中华创伤杂志(英文版)

Bradycardia is the most common form of dysrhythmia developing after disruption of the sympathetic pathway by a spinal cord injury (SCI), and it can have fatal consequences, including cardiac arrest. Here, we report a case of cardiac arrest developing after cervical SCI attributable to sympathetic hypoactivity. A 26-year-old male pedestrian was admitted after a traffic accident. Radiologically, fractures were apparent at the Cbilateral articular facets, and cord contusion with hemorrhage was evident at C. During his stay in ICU, intermittent bradycardia was noted, but the symptoms were not specific. On the 22nd postoperative day, the patient was taken to the computed tomography suite for further evaluation and experienced cardiac arrest during a positional change. After immediate cardiac massage, the patient was resuscitated. We scheduled Holter monitoring, which detected 26 pauses, the longest of which was 17.9 s. The patient underwent cardiac pacemaker insertion. No further cardiac events were noted.

Study of Changes in Sympathetic and Parasympathetic Autonomic Functions in Patients of Depression in Rural Western Maharashtra

Introduction The deficiency of monoaminergic neurotransmission is important key pathology of depression. With these changes in excitatory neurotransmission in brain it can be hypothesised that this alteration may result into changes in various sympathetic and parasympathetic parameters like Blood pressure, Heart rate and expiratory and inspiratory ratio. Methodology It is a Case Control Observational Study done in collaboration with department of Psychaitry and all patients of depression satisfying the inclusion and exclusion criteria were studied for the changes in Blood pressure using handgrip test and Orthostatic Hypotensive Test while changes resting heart rate was recorded. Result and Conclusion There was increase in heart rate found in depression whereas blood pressure diastolic and systolic were found to be lower than a normal individual.

Morphological investigations of the cervicothoracic sympathetic system in the horse (Equus ferrus caballus) in Egypt / Investigaciones morfológicas del sistema simpático cervicotorácico en el caballo (Equus ferrus caballus) en Egipto

The current study was performed on twelve healthy adult horses (E. ferrus caballus) collected from Egypt were dissected to provide anatomical descriptions of bilaterally cervicothoracic sympathetic system macroscopically. On the left side, cervicothoracic sympathetic system is represented only by the caudal cervical ganglion, which presents on lateral surface of esophagus, cranial to the level of first rib. On right side, cervicothoracic sympathetic system is represented by the caudal and middle cervical ganglion. Caudal cervical ganglion was consisted of the fusion of eighth cervical and first three thoracic nerve ganglia. Caudal directed continuation branch of left ansa subclavia gave off a pericardial branch and then gave branch for ligamentum arteriosum. There are special sympathetic­parasympathetic communicating branches; on left side, there is only one branch that was present on lateral surface of esophagus, while on right side, there were four branches; two from caudal cervical ganglion and two from middle cervical ganglion. The most suitable site of ganglion blocks from both sides; needle was placed medioventrally between the articulation of first and second rib.

Doce caballos (E. ferrus caballus) adultos sanos, procedentes de Egipto, fueron disecados para realizar descripciones anatómicas macroscópicas del sistema simpático cervicotorácico bilateralmente. En el lado izquierdo, el sistema simpático cervicotorácico estuvo representado sólo por el ganglio cervical caudal, en la superficie lateral del esófago, craneal en relación a la primera costilla. En el lado derecho, el sistema simpático cervicotorácico estuvo representado por los ganglios caudal y cervical medio. El ganglio cervical caudal consistió en la fusión del octavo ganglio cervical y el primero de los tres ganglios torácicos. Se observaron ramos comunicantes entre los sistemas simpático y parasimpático; en el lado izquierdo, sólo hubo una rama presente en la superficie lateral del esófago, mientras que en el lado derecho, se observaron cuatro ramos: dos del ganglio cervical caudal y dos del ganglio cervical medio. El sitio más adecuado para la ejecución de los bloqueos ganglionares de ambos lados es a nivel medioventral, entre la articulación de la primera con la segunda costilla.