Desenpenho aer��bio e controle auton��mico card��aco em idosas praticantes de tai chi chuan e sedent��rias

Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico

Efeito do treinamento resistido na fun����o aut��nomica card��aca, nos par��metros bioqu��micos e antropom��tricos de pessoas vivendo com HIV/AIDS

Introduction: The emergence of High Active Antiretroviral Therapy (HAART) increase the life expectancy of the persons living with HIV/AIDS (PLHIV), therefore the prolonged use cause metabolic implications and influences on body fat distribution and increase the cardiovascular diseases prevalence. Aims: Evaluate the effect of resistance training on heart rate variability, biochemical parameters and somatotype on PLHIV. Methods: Participated this study seven sedentary men, with age above 25 years old, living with HIV/AIDS, under HAART use. Were submitted a 16 week intervention with resistance training. Evaluated the heart rate variability, biochemical parameters and somatotype, before, after 8 weeks and 16 weeks, all in paired form. It was found the data normality by Shapiro-Wilk test and conducted the Anova one way combined with Tukey post hoc to samples in each evaluate moment, adopting significance level p<0,05. Also were calculated percentage change deltas. For somatotype was used the somatotype spatial distance (DES), obeying the significance value DES&#8805;1. Results: Was found significance differences only in variable final heart rate delta 60s (p=0,01), however, is not showed changes on heart rate variability, biochemical parameters and somatotype components. Conclusion: 16 weeks of resistance training showed improvement on heart rate recovery after submaximal effort and, despite is not enough to produce significance differences on biochemical parameters and somatotype components, could be realize improvement on average value of fasting glucose and lipid profile, as well as reducing the endomorphic component

Analysis of cardiac autonomic modulation in obese and eutrophic children

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Analysis of cardiovascular system responses to forced vital capacity in COPD

CONTEXTUALIZA����O: O teste de capacidade vital for��ada (CVF) �� rotineiramente realizado na avalia����o da fun����o pulmonar de pacientes com doen��a pulmonar obstrutiva cr��nica (DPOC). Entretanto, permanece pouco compreendida a influ��ncia do teste de CVF sobre o sistema cardiovascular de pacientes com DPOC. OBJETIVOS: Analisar o comportamento da frequ��ncia card��aca (FC), press��o arterial (PA) e variabilidade da frequ��ncia card��aca (VFC) no teste de CVF na DPOC. M��TODOS: Dezenove homens com DPOC (72 �� 7 anos, no est��gio de gravidade GOLD I=3, II=5, III=7 e IV=4 pacientes) realizaram a manobra de CVF e tiveram sua FC monitorada durante todo o exame, e a VFC analisada nos dom��nios do tempo (rMSSD) e da frequ��ncia (BF, AF e BF/AF) durante o repouso, antes e ap��s a melhor manobra de CVF. A PA foi analisada no repouso, imediatamente ao final da manobra de CVF e 10 minutos ap��s o t��rmino de todos os testes. RESULTADOS: Ao in��cio da manobra de CVF, a FC reduziu (p<0,001) e, em seguida, aumentou progressivamente at�� o final do teste (p<0,001). Ap��s t��rmino da manobra, a FC continuou a aumentar at�� atingir um pico (p<0,001) e depois caiu rapidamente a valores inferiores aos de repouso (p<0,001) e retornou ao seu valor basal. A PA e os ��ndices da VFC n��o sofreram altera����es nos per��odos analisados. CONCLUS��O: O teste de CVF influencia o comportamento da FC, sem alterar o seu controle auton��mico, bem como a PA em pacientes com DPOC nos per��odos analisados.

��ndices geom��tricos de variabilidade da frequ��ncia card��aca na doen��a pulmonar obstrutiva cr��nica

Background: It was already evidenced decreased heart rate variability (HRV) in chronic obstructive pulmonary disease (COPD) patients at rest.Objective: In order to insert new elements in the literature regarding this issue, we evaluated geometric index of HRV in COPD subjects.Method: We analyzed data from 34 volunteers, divided into two groups according to spirometric values: COPD (17 volunteers, FEV1/FVC = 47.3 +/- 10.2; FEV1 = 50.8 +/- 15.7) and control (17 volunteers, FEV1/FVC = 78.8 +/- 10.8; FEV1 = 100.1 +/- 14.7). For analysis of HRV indexes the volunteers remained in the supine position for 30 minutes. We analyzed the following indexes: triangular index (RRtri), triangular interpolation of RR intervals (TINN) and Poincare plot (SD1, SD2 and SD1/SD2). Student t test for unpaired samples and Mann-Whitney test were used for data analysis.Results: We observed statistically significant reductions in geometric indexes in the COPD group: RRtri (0.043 +/- 0.01 vs. 0.059 +/- 0.02; p = 0.018), TINN (105.88 +/- 51.82 vs. 151.47 +/- 49.9; p=0.014), SD1 (9.76 +/- 4.66 vs. 14.55 +/- 6.04; p = 0.014) and SD2 (34.86 +/- 17.02 vs. 51.51 +/- 18.38; p = 0.010). SD1/5D2 (0.30 +/- 0.11 vs. 0.28 +/- 0.07; p = 0.605) were not significantly different between groups. Patients with COPD presented a visual analysis of Poincare plot of lower dispersion of RR intervals both beat to beat and the long term.Conclusion: Subjects with COPD present reduction of geometric indexes of HRV, indicating reduced heart rate variability. (C) 2010 Sociedade Portuguesa de Pneumologia. Published by Elsevier Espana, S.L. All rights reserved.

No����es b��sicas de variabilidade da frequ��ncia card��aca e sua aplicabilidade cl��nica

O sistema nervoso aut��nomo (SNA) desempenha um papel importante na regula����o dos processos fisiol��gicos do organismo humano tanto em condi����es normais quanto patol��gicas. Dentre as t��cnicas utilizadas para sua avalia����o, a variabilidade da frequ��ncia card��aca (VFC) tem emergido como uma medida simples e n��o-invasiva dos impulsos auton��micos, representando um dos mais promissores marcadores quantitativos do balan��o auton��mico. A VFC descreve as oscila����es no intervalo entre batimentos card��acos consecutivos (intervalos R-R), assim como oscila����es entre frequ��ncias card��acas instant��neas consecutivas. Trata-se de uma medida que pode ser utilizada para avaliar a modula����o do SNA sob condi����es fisiol��gicas, tais como em situa����es de vig��lia e sono, diferentes posi����es do corpo, treinamento f��sico, e tamb��m em condi����es patol��gicas. Mudan��as nos padr��es da VFC fornecem um indicador sens��vel e antecipado de comprometimentos na sa��de. Uma alta variabilidade na frequ��ncia card��aca �� sinal de boa adapta����o, caracterizando um indiv��duo saud��vel, com mecanismos auton��micos eficientes, enquanto que, baixa variabilidade �� frequentemente um indicador de adapta����o anormal e insuficiente do SNA, implicando a presen��a de mau funcionamento fisiol��gico no indiv��duo. Diante da sua import��ncia como um marcador que reflete a atividade do SNA sobre o n��dulo sinusal e como uma ferramenta cl��nica para avaliar e identificar comprometimentos na sa��de, este artigo revisa aspectos conceituais da VFC, dispositivos de mensura����o, m��todos de filtragem, ��ndices utilizados para an��lise da VFC, limita����es de utiliza����o e aplica����es cl��nicas da VFC.

Efeito da t��cnica de oscila����o oral de alta freq����ncia aplicada em diferentes press��es expirat��rias sobre a fun����o auton��mica do cora����o e os par��metros cardiorrespirat��rios

O objetivo deste estudo foi avaliar o efeito da t��cnica de oscila����o oral de alta freq����ncia (com o aparelho Shaker), aplicada em diferentes press��es expirat��rias (PE), sobre a fun����o auton��mica e par��metros cardiorrespirat��rios. Foram coletados dados de 20 volunt��rios jovens saud��veis (21,6��1,3 anos), que permaneceram em repouso inicial por 10 minutos e, em seguida, fizeram tr��s s��ries de dez expira����es no aparelho (com intervalo de descanso de 2 minutos entre as s��ries) em tr��s diferentes PE - press��o livre (PL), de 10 (P10) e de 20 (P20) cmH2O - permanecendo por mais 10 minutos em repouso final. Os dados foram analisados estatisticamente, com n��vel de signific��ncia de 5%. Ap��s a aplica����o da t��cnica, constatou-se diferen��a significante nos ��ndices de variabilidade da freq����ncia card��aca em PL e um aumento significante na press��o arterial sist��lica em P20. Na press��o arterial diast��lica, freq����ncia respirat��ria e satura����o perif��rica de oxig��nio n��o foram encontradas diferen��as antes, durante e ap��s a t��cnica, nas diferentes PE. A percep����o do esfor��o aumentou significantemente ao longo das s��ries em PL e P20 e entre P10 e P20 em cada s��rie. A freq����ncia card��aca (FC) aumentou e diminuiu em sincronia com os movimentos de inspira����o e expira����o, respectivamente. Foram observadas modifica����es na modula����o auton��mica do cora����o em PL. A aplica����o da t��cnica nessa popula����o, nas diferentes PE analisadas, promoveu modifica����es no comportamento da FC, no esfor��o percebido e, em PL, na modula����o auton��mica do cora����o.

For��a muscular respirat��ria, qualidade de vida e modula����o auton��mica da frequ��ncia card��aca na distrofia miot��nica

Background: The myotonic dystrophy (MD) is a multisystem neuromuscular disease that can affect the respiratory muscles and heart function, and cause impairment in quality of life. Objectives: Investigate the changes in respiratory muscle strength, health-related quality of life (HRQoL) and autonomic modulation heart rate (HR) in patients with MD. Methods: Twenty-three patients performed assessment of pulmonary function, sniff nasal inspiratory pressure (SNIP), the maximal inspiratory (MIP) and expiratory (MEP) pressure, and of HRQoL (SF-36 questionnaire). Of these patients, 17 underwent assessment of heart rate variability (HRV) at rest, in the supine and seated positions. Results: The values of respiratory muscle strength were 64, 70 and 80% of predicted for MEP, MIP, and SNIP, respectively. Significant differences were found in the SF-36 domains of physical functioning (58.7 �� 31,4 vs. 84.5 �� 23, p<0.01) and physical problems (43.4 �� 35.2 vs. 81.2 �� 34, p<0.001) when patients were compared with the reference values. Single linear regression analysis demonstrated that MIP explains 29% of the variance in physical functioning, 18% of physical problems and 20% of vitality. The HRV showed that from supine position to seated, HF decreased (0.43 x 0.30), and LF (0.57 x 0.70) and the LF/HF ratio (1.28 x 2.22) increased (p< 0.05). Compared to healthy persons, LF was lower in both male patients (2.68 x 2.99) and women (2.31 x 2.79) (p< 0.05). LF / HF ratio and LF were higher in men (5.52 x 1.5 and 0.8 x 0.6, p <0.05) and AF in women (0.43 x 0.21) (p< 0.05). There was positive correlation between the time of diagnosis and LF / HF ratio (r = 0.7, p <0.01). Conclusions: The expiratory muscle strength was reduced. The HRQoL was more impaired on the physical aspects and partly influenced by changes in inspiratory muscle strength. The HRV showed that may be sympathetic dysfunction in autonomic modulation of HR, although with normal adjustment of autonomic modulation during the change of posture. The parasympathetic modulation is higher in female patients and sympathetic tends to increase in patients with longer diagnosis

Auditory stimulation and cardiac autonomic regulation

Previous studies have already demonstrated that auditory stimulation with music influences the cardiovascular system. In this study, we described the relationship between musical auditory stimulation and heart rate variability. Searches were performed with the Medline, SciELO, Lilacs and Cochrane databases using the following keywords: auditory stimulation, autonomic nervous system, music and heart rate variability. The selected studies indicated that there is a strong correlation between noise intensity and vagal-sympathetic balance. Additionally, it was reported that music therapy improved heart rate variability in anthracycline-treated breast cancer patients. It was hypothesized that dopamine release in the striatal system induced by pleasurable songs is involved in cardiac autonomic regulation. Musical auditory stimulation influences heart rate variability through a neural mechanism that is not well understood. Further studies are necessary to develop new therapies to treat cardiovascular disorders.

Dysautonomia and ventricular dysfunction in the indeterminate form of Chagas disease

Background: the associations between autonomic function and biventricular function in patients with the indeterminate form of Chagas disease remains to be elucidated.Methods: In 42 asymptornatic patients and 19 healthy volunteers, the autonomic function was assessed by time domain indices of heart rate variability (HRV), analyzed for 24 h; the right ventricular function was assessed by fraction area change, right ventricle shortening, and systolic excursion of the tricuspid valve; and the left ventricular function was assessed by ejection fraction and transmittal flow velocities. Data were expressed as mean SD or medians (including the lower quartile and upper quartile). Groups were compared by Student's t or Mann-Whitney U test. Autonomic and ventricular function were correlated by Pearson's or Spearman's correlation coefficient. The level of significance was 5%.Results: Right and left ventricular systolic function indexes were comparable between groups. Transmittal flow velocities were decreased in the Chagas disease group (p < 0.05). The patients presented impaired HRV as indicated by the values of SDNN-day (80 (64-99) ms vs. 98 (78-127) ms; p = 0.045), SDNNI-24 It (54 (43-71) vs. 65 (54-105) ms; p = 0.027), SDNNI-day (49 (42-64) vs. 67 (48-76) ms; p = 0.045), pNN50-day (2.2 (0.7-5)% vs. 10 (3-11)%; p = 0.033); and pNN50-24 It (3 (1-7)% vs. 12 (8-19)%; p = 0.013). There were no correlations between the left ventricular diastolic indices and autonomic dysfunctional indices (p > 0.05).Conclusion: Patients with the indeterminate form of Chagas disease have both dysautonomia, and left ventricular diastolic dysfunction. However, the right ventricular function is preserved. Importantly, ventricular diastolic dysfunction and dysautonomia. are independent phenomena. (c) 2005 Elsevier B.V.. All rights reserved.

A Simple Approach to Assess VT During a Field Walk Test

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Could a high-fat diet rich in unsaturated fatty acids impair the cardiovascular system?

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

��ndices geom��tricos de variabilidade da frequ��ncia card��aca em crian��as obesas e eutr��ficas

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Efeitos agudos do tabagismo sobre a modula����o auton��mica: an��lise por meio do plot de poincar��

FUNDAMENTO: O tabagismo altera a fun����o auton��mica. OBJETIVO: Investigar os efeitos agudos do tabagismo sobre a modula����o auton��mica e a recupera����o dos ��ndices de variabilidade de frequ��ncia card��aca (VFC) p��s-fumo, por meio do plot de Poincar�� e ��ndices lineares. M��TODOS: Foram avaliados 25 fumantes jovens, os quais tiveram a frequ��ncia card��aca analisada, batimento a batimento, na posi����o sentada, ap��s 8 horas de abstin��ncia, por 30 minutos em repouso, 20 minutos durante o fumo e 30 minutos p��s-fumo. An��lise de vari��ncia para medidas repetidas, seguido do teste de Tukey, ou teste de Friedman seguido do teste de Dunn foram aplicados dependendo da normalidade dos dados, com p < 0,05. RESULTADOS: Durante o fumo, houve redu����o dos ��ndices SD1 (23,4 �� 9,2 vs 13,8 �� 4,8), raz��o SD1/SD2 (0,31 �� 0,08 vs 0,2 �� 0,04), RMSSD (32,7 �� 13 vs 19,1 �� 6,8), SDNN (47,6 �� 14,8 vs 35,5 �� 8,4), HFnu (32,5 �� 11,6 vs 19 �� 8,1) e do intervalo RR (816,8 �� 89 vs 696,5 �� 76,3) em rela����o ao repouso, enquanto que aumentos do ��ndice LFnu (67,5 �� 11,6 vs 81 �� 8,1) e da raz��o LF/HF (2,6 �� 1,7 vs 5,4 �� 3,1) foram observados. A an��lise visual do plot mostrou menor dispers��o dos intervalos RR durante o fumo. Com exce����o da raz��o SD1/SD2, os demais ��ndices apresentaram recupera����o dos valores, 30 minutos ap��s o tabagismo. CONCLUS��O: O tabagismo produziu agudamente modifica����es no controle auton��mico, caracterizadas por ativa����o simp��tica e retirada vagal, com recupera����o 30 minutos ap��s o fumo.

Sidestream cigarette smoke and cardiac autonomic regulation

Background: The literature has already demonstrated that cigarette influences the cardiovascular system. In this study, we performed a literature review in order to investigate the relationship between sidestream cigarette smoke (SSCS) and cardiac autonomic regulation. Methods. Searches were performed on Medline, SciELO, Lilacs and Cochrane databases using the crossing between the key-words: cigarette smoking, autonomic nervous system, air pollution and heart rate variability. Results: The selected studies indicated that SSCS exposure affects the sympathetic and parasympathetic responses to changes in arterial blood pressure. Moreover, heart rate responses to environmental tobacco smoke are increased in smokers compared to non-smokers. The mechanism involved on this process suggest increased oxidative stress in brainstem areas that regulate the cardiovascular system. Conclusion: Further studies are necessary to add new elements in the literature to improve new therapies to treat cardiovascular disorders in subjects exposed to sidestream cigarette smoke. �� 2013 Valenti et al; licensee BioMed Central Ltd.