HRV analysis: Unpredictability of approximate entropy in chronic obstructive pulmonary disease

Introduction: Approximate entropy (ApEn) is a widely imposed metric to evaluate a chaotic response and irregularities of RR-intervals from an electrocardiogram. Yet, the technique is problematic due to the accurate choice of the tolerance (r) and embedding dimension (M). We prescribed the metric to evaluate these responses in subjects exhibiting symptoms of chronic obstructive pulmonary disease (COPD) and we strived to overcome this disadvantage by applying different groupings to detect the optimal. Methods: We examined 38 subjects split equally: COPD and control. To evaluate autonomic modulation the heart rate was measured beat-by-beat for 30 min in a supine position without any physical, sensory, or pharmacological stimuli. In the time-series obtained the ApEn was then applied with set values for tolerance, r and embedding dimension, M. Then, the differences between the two groups and their effect size by two measures (Cohen’s ds and Hedges’s gs) were computed. Results: The highest value of statistical significance accomplished for any effect size statistical combinations undertaken was -1.13 for Cohen’s ds, and -1.10 for Hedges’s gs with embedding dimension, M = 2 and tolerance, r = 0.1. Conclusion: ApEn was capable of optimally identifying the decrease in chaotic response in COPD. The optimal combination of r and M for this were 0.1 and 2, respectively. Despite this, ApEn is a relatively unpredictable mathematical marker and the use of other techniques to evaluate a healthy or pathological condition is encouraged

Autonomic Modulation in Duchenne Muscular Dystrophy during a Computer Task: A Prospective Control Trial

Introduction Duchenne Muscular Dystrophy (DMD) is characterized by progressive muscle weakness that can lead to disability. Owing to functional difficulties faced by individuals with DMD, the use of assistive technology is essential to provide or facilitate functional abilities. In DMD, cardiac autonomic dysfunction has been reported in addition to musculoskeletal impairment. Consequently, the objective was to investigate acute cardiac autonomic responses, by Heart Rate Variability (HRV), during computer tasks in subjects with DMD. Method HRV was assessed by linear and nonlinear methods, using the heart rate monitor Polar RS800CX chest strap Electrocardiographic measuring device. Then, 45 subjects were included in the group with DMD and 45 in the healthy Typical Development (TD) control group. They were assessed for twenty minutes at rest sitting, and five minutes after undergoing a task on the computer. Results Individuals with DMD had a statistically significant lower parasympathetic cardiac modulation at rest when compared to the control group, which further declined when undergoing the tasks on the computer. Conclusion DMD patients presented decreased HRV and exhibited greater intensity of cardiac autonomic responses during computer tasks characterized by vagal withdrawal when compared to the healthy TD control subjects

Effects of resistance training protocols on nonlinear analysis of heart rate variability in metabolic syndrome

Besides some non-linear measurements used in autonomic modulation (AM) analysis can be suitable using short term series, they usually depend on long time-series of data. To transpose this, chaotic global methods were formulated, putting together heart rate variability (HRV) linear methods. Chaos provides information about vegetative function control related to cardiovascular risks. Applying this method to investigate the complexity of the health condition after resistance training protocols, used as a therapeutic intervention, on AM in metabolic syndrome individuals (MetS) is important. This study aimed to compare the effects of two resistance training programs (conventional vs. functional) in MetS using nonlinear analysis of AM. MetS subjects (n=50), both sexes, aged 40 to 60 years were randomized between two programs. Also, there was a control group (n=12). Both groups performed 30 sessions of training. AM was accessed in chaos domain by chaotic global techniques. The main results showed that both resistance training, functional and conventional, increased chaos when compared to the control group, respectively observed by CFP1 (13.9±17.9 vs. 12.8±14.4 vs. -2.23±7.96; p≤0.05) and CFP3 (15.4±19.8 vs. 21.9±13.2 vs. -4.82±11.4; p≤0.05). In addition, 30 sessions of both resistance programs increase chaos, and nonlinear analysis enables discriminates AM after interventions when compared to control group

Effects of exercise on cardiac autonomic modulation in children: literature update

AbstractIntroduction It is known that physical exercise is beneficial and precipitates adjustments to the autonomic nervous system. However, the effect of exercise on cardiac autonomic modulation in children, despite its importance, is poorly investigated.Objective To bring together current information about the effects of exercise on heart rate variability in healthy and obese children.Methods The literature update was performed through a search for articles in the following databases; PubMed, PEDro, SciELO and Lilacs, using the descriptors “exercise” and “child” in conjunction with the descriptors “autonomic nervous system”, “sympathetic nervous system”, “parasympathetic nervous system” and also with no descriptor, but the key word of this study, “heart rate variability”, from January 2005 to December 2012.Results After removal of items that did not fit the subject of the study, a total of 9 articles were selected, 5 with healthy and 4 with obese children.Conclusion The findings suggest that exercise can act in the normalization of existing alterations in the autonomic nervous system of obese children, as well as serve as a preventative factor in healthy children, enabling healthy development of the autonomic nervous system until the child reaches adulthood

Apparent and content validation of maternal self-efficiency scale for prevention of childhood diarrhea

AIM: The aim of this paper is to describe the apparent and content validation for the Maternal Self-Efficiency Scale for the Prevention of Childhood Diarrhoea. METHOD: Methodological study with the execution of apparent and content validation by seven judges; semantic analysis, by 30 mothers of children under 5 years old and also a pre-test involving 31 mothers who have been selected through convenience. It has been considered necessary to have the agreement of at least 70% of the judges for apparent validation and a minimum of 80% for pertinence and Index of Content Validation. RESULTS: This paper shows that most items have been considered clear, comprehensive and relevant by the judges. The final Content Validity Index of the scale was 0.96. The suggestions of the mothers were accepted. CONCLUSION: The scale ended up having 25 items and two domains (family hygiene and general/eating practices) which assess the maternal self-efficiency for the prevention of diarrhea in their children, thereby contributing to the planning of nursing interventions

Variabilidade da frequência cardíaca como recurso em fisioterapia: análise de periódicos nacionais

INTRODUCTION: The autonomic nervous system (ANS) could be investigated in a noninvasive way by the heart rate variability analysis (HRV) which has contributed to several health areas such as physiotherapy. OBJECTIVE: To gather information regarding the use of HRV on physiotherapy aims at providing an update of the findings for the area on journals of national circulation. MATERIALS AND METHODS: The journals of national circulation classified as greater than B2 or B2 and with free access and complete texts in some internet sites were searched on 21 area WebQualis resulting on selection of Revista Brasileira de Fisioterapia, Fisioterapia e Pesquisa and Fisioterapia em Movimento using the keywords: autonomic nervous system, sympathetic nervous system, physiotherapy and heart rate variability. RESULTS: The search resulted in 19 articles being 17 clinical trials and two case reports. CONCLUSION: The HRV has been used as a resource of interventions evaluation, as pathological conditions common to clinical practice investigation and to physiological conditions interpretation in physiotherapy. The HRV is principally used to the cardiorespiratory specialty of physiotherapy.INTRODUÇÃO: O sistema nervoso autônomo (SNA) pode ser investigado de forma não invasiva a partir da análise da variabilidade da frequência cardíaca (VFC) e sua utilização para avaliação do SNA tem contribuído com várias áreas da saúde, dentre elas, a fisioterapia. OBJETIVOS: Reunir estudos publicados em periódicos de circulação nacional da área que abordassem a utilização da VFC em fisioterapia, a fim de fornecer uma atualização dos achados para a área. MATERIAIS E MÉTODOS: Foram selecionados, na lista de periódicos do WebQualis da área 21, todos os periódicos de circulação nacional que utilizam a palavra fisioterapia em seu título, com disponibilidade livre e textos completos em algum sítio da internet e que possuíssem classificação maior ou igual a B2. Com esses critérios, foram selecionados artigos das seguintes revistas: Revista Brasileira de Fisioterapia, Fisioterapia e Pesquisa e Fisioterapia em Movimento. Para essa busca, foram utilizados os descritores: sistema nervoso autônomo, sistema nervoso simpático, fisioterapia e variabilidade da frequência cardíaca. RESULTADOS: A busca resultou em 19 artigos, sendo 17 ensaios clínicos e dois relatos de caso. CONCLUSÃO: A VFC tem sido utilizada no âmbito da fisioterapia como recurso para avaliação de intervenções fisioterapêuticas, como forma de investigação de condições patológicas comuns à prática clínica e para interpretação de condições fisiológicas. A sua utilização é feita principalmente pela especialidade de fisioterapia cardiorrespiratória