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1.
Am J Physiol Regul Integr Comp Physiol ; 317(4): R539-R551, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31365303

RESUMO

In heart period (HP) variability (HPV) recordings the percentage of negative HP variations tends to be greater than that of positive ones and this pattern is referred to as HPV asymmetry (HPVA). HPVA has been studied in several experimental conditions in healthy and pathological populations, but its origin is unclear. The baroreflex (BR) exhibits an asymmetric behavior as well given that it reacts more importantly to positive than negative arterial pressure (AP) variations. We tested the hypothesis that the BR asymmetry (BRA) is a HPVA determinant over spontaneous fluctuations of HP and systolic AP (SAP). We studied 100 healthy subjects (age from 21 to 70 yr, 54 men) comprising 20 subjects in each age decade. Electrocardiogram and noninvasive AP were recorded for 15 min at rest in supine position (REST) and during active standing (STAND). The HPVA was evaluated via Porta's index and Guzik's index, while the BRA was assessed as the difference, and normalized difference, between BR sensitivities computed over positive and negative SAP variations via the sequence method applied to HP and SAP variability. HPVA significantly increased during STAND and decreased progressively with age. BRA was not significantly detected both at REST and during STAND. However, we found a significant positive association between BRA and HPVA markers during STAND persisting even within the age groups. This study supports the use of HPVA indexes as descriptors of BRA and identified a challenge soliciting the BR response like STAND to maximize the association between HPVA and BRA markers.

2.
Lasers Med Sci ; 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31203569

RESUMO

To evaluate the photobiomodulation (PBM) effect on the cardiovascular autonomic control, analyzed by baroreflex sensitivity (sequence method), during constant load exercise and recovery in diabetic men, we evaluated 11 men with type 2 diabetes (DM2) (40-64 years). The constant workload exercise protocol (TECC) was performed on two different days, 14 days apart from each other, to guarantee PBM washout period. After PBM by light-emitting diode (LED) irradiation (150 J or 300 J or placebo), 10 min of rest (REST) was performed. After this period, the volunteer was positioned on a cycloergometer to start the test (1-min rest, 3-min free-load heating, 6-min constant workload-EXERCISE, 6-min free-load cool-down, 1-min rest) followed by a sitting period of 10 min (RECOVERY). The constant workload corresponded to 80%VO2GET (gas exchange threshold) identified by a previous cardiopulmonary exercise test (CPET). PBM was applied in continuous mode, contact technique, bilaterally, on both femoral quadriceps and gastrocnemius muscle groups. The electrocardiogram R-R intervals (BioAmp FE132) and the peripheral pulse pressure signals (Finometer PRO) were collected continuously throughout the protocol. Stable sequences of 256 points were chosen at REST, EXERCISE, and RECOVERY. The baroreflex sensitivity (BRS) was computed in time domain according to the sequence method (αseq). The comparison between therapies (150 J/300 J/placebo) and condition (REST, EXERCISE, and RECOVERY) was performed using the ANOVA two-way repeated measures test. There was no interaction between therapy and conditions during the TECC. There was only the condition effect (p < 0.001), showing that the behavior of αseq was similar regardless of the therapy. Photobiomodulation with 150 J or 300 J applied previously to a moderate-intensity TECC in DM2 was not able to promote cardiovascular autonomic control changes leading to an improvement in BRS.

3.
Trials ; 20(1): 258, 2019 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-31064379

RESUMO

BACKGROUND: Inspiratory muscle training (IMT) has brought great benefits in terms of improving physical performance in healthy individuals. However, there is no consensus regarding the best training load, as in most cases the maximal inspiratory pressure (MIP) is used, mainly the intensity of 60% of MIP. Therefore, prescribing an IMT protocol that takes into account inspiratory muscle strength and endurance may bring additional benefits to the commonly used protocols, since respiratory muscles differ from other muscles because of their greater muscular resistance. Thus, IMT using critical inspiratory pressure (PThC) can be an alternative, as the calculation of PThC considers these characteristics. Therefore, the aim of this study is to propose a new IMT protocol to determine the best training load for recreational cyclists. METHODS: Thirty recreational cyclists (between 20 and 40 years old) will be randomized into three groups: sham (SG), PThC (CPG) and 60% of MIP, according to age and aerobic functional capacity. All participants will undergo the following evaluations: pulmonary function test (PFT), respiratory muscle strength test (RMS), cardiopulmonary exercise test (CPET), incremental inspiratory muscle endurance test (iIME) (maximal sustained respiratory pressure for 1 min (PThMAX)) and constant load test (CLT) (95%, 100% and 105% of PThMÁX) using a linear load inspiratory resistor (PowerBreathe K5). The PThC will be calculated from the inspiratory muscle endurance time (TLIM) and inspiratory loads of each CLT. The IMT will last 11 weeks (3 times/week and 55 min/session). The session will consist of 5-min warm-up (50% of the training load) and three sets of 15-min breaths (100% of the training load), with a 1-min interval between them. RMS, iIME, CLT and CPET will be performed beforehand, at week 5 and 9 (to adjust the training load) and after training. PFT will be performed before and after training. The data will be analyzed using specific statistical tests (parametric or non-parametric) according to the data distribution and their respective variances. A p value <0.05 will be considered statistically significant. DISCUSSIONS: It is expected that the results of this study will enable the training performed with PThC to be used by health professionals as a new tool to evaluate and prescribe IMT. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02984189 . Registered on 6 December 2016.

4.
Clinics (Sao Paulo) ; 73: e439, 2018 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-30379226

RESUMO

OBJECTIVE: The objective of this study was to investigate the interaction among the determinants of expiratory flow limitation (EFL), peak oxygen uptake (VO2peak), dysanapsis ratio (DR) and age during cycling at different intensities in young and middle-aged men. METHODS: Twenty-two (11 young and 11 middle-aged) men were assessed. Pulmonary function tests (DR), cardiopulmonary exercise tests (VO2peak) and two constant load tests (CLTs) at 75% (moderate intensity) and 125% (high intensity) of the gas exchange threshold were performed to assess EFL. EFL was classified using the percentage of EFL determined from both CLTs (mild: 5%-30%, moderate: 30%-50%, severe: >50%). RESULTS: Only the middle-aged group displayed EFL at both exercise intensities (p<0.05). However, the number of participants with EFL and the percentage of EFL were only associated with age during high-intensity exercise. CONCLUSIONS: There was no interaction between the determinants. However, age was the only factor that was related to the presence of EFL during exercise in the age groups studied.

5.
Physiol Meas ; 39(10): 104004, 2018 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-30207986

RESUMO

BACKGROUND: Probabilistic causality (PC) is a framework for checking that the occurrence of a cause raises the probability of the effect by comparing the probability of the effect conditioned and unconditioned to the cause. Even though it is less frequently utilized with respect to the more traditional model-based Wiener-Granger causality (WGC) that is based on the predictability improvement of an effect resulting from the inclusion of the presumed cause in the multivariate linear regression model, PC has the advantage of being model-free. OBJECTIVE: The aim of the study is to apply the PC framework to assess the evolution of cardiac baroreflex control with age from spontaneous fluctuations of heart period (HP) and systolic arterial pressure (SAP) and to compare it to the more common WGC approach. APPROACH: We studied 100 healthy humans (54 males, age: 21-70 years, 20 subjects for each 10 years bin). HP and SAP were extracted on a beat-to-beat basis from 5 min recordings of electrocardiogram and plethysmographic arterial pressure at rest in supine position (REST) and during active standing (STAND) under spontaneous breathing. The WGC ratio (WGCR) was computed as the log ratio of the prediction error variance of the autoregressive model on HP to that on HP with exogenous SAP. The PC ratio (PCR) was computed as the probability of observing an HP ramp given an associated parallel SAP variation divided by the probability of observing an HP ramp. MAIN RESULTS: The WGCR and PCR suggested the gradual impairment of cardiac baroreflex with age, especially during STAND. Moreover, they were significantly associated both at REST and during STAND but the degree of the PCR-WGCR association was weak. SIGNIFICANCE: PC can be effectively exploited to assess modification of the cardiovascular control during senescence even though a limited agreement was observed with WGC.

6.
Conscientiae saúde (Impr.) ; 17(2): 219-229, jun. 2018.
Artigo em Português | LILACS-Express | ID: biblio-916265

RESUMO

Introdução: A lombalgia se caracteriza como uma dor de origem multifatorial que pode resultar em alterações no sistema nervoso autônomo. Estas alterações são identificadas pelo aumento da modulação simpática cardíaca levando a diminuição da variabilidade da frequência cardíaca (VFC). Objetivo: Realizar uma revisão literatura acerca do uso da VFC em pacientes com lombalgia. Métodos: A busca sistemática desse estudo foi conduzida através das bases de dados LILACS, PubMED, CINAHL e SciELO. Resultados: Foram incluídos na revisão apenas dez estudos que mostravam a relação entre a lombalgia e as respostas dos índices da VFC. Destes, sete estudos relatam melhora/relação dos índices da VFC com a lombalgia e outros estudos não mostram alteração das respostas. Conclusão: Existem poucas evidências apresentando a relação entre a lombalgia e as respostas dos índices da VFC na literatura. Além disso, os resultados se mostram inconclusivos, fato este que dificulta afirmar se há relação ou melhora dos índices da VFC após intervenção em pacientes com lombalgia.


Introduction: Low back pain has multifactorial etiology and may result in changes on autonomic nervous system, such as increasing cardiac sympathetic modulation and decreasing heart rate variability (HRV). Objective: To carry out a review about the use of HRV in patients with low back pain. Methods: The systematic search of this study was conducted through the LILACS, PubMED, CINAHL and SciELO databases. Results: Ten studies that showed the relationship between low back pain and HRV index responses were included in the review. The results show that seven studies report an improvement/relation of HRV index with low back pain and other two studies did not show altered responses. Conclusion: There are few evidence reporting the relationship between low back pain and HRV responses in the literature. Moreover, the results are inconclusive which makes it difficult to affirm that there is a relationship or improvement in the HRV index after intervention in patients with low back pain.

7.
J Appl Physiol (1985) ; 124(3): 791-804, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29212671

RESUMO

Aging affects baroreflex regulation. The effect of senescence on baroreflex control was assessed from spontaneous fluctuations of heart period (HP) and systolic arterial pressure (SAP) through the HP-SAP gain, while the HP-SAP phase and strength are usually disregarded. This study checks whether the HP-SAP phase and strength, as estimated, respectively, via the phase of the HP-SAP cross spectrum (PhHP-SAP) and squared coherence function (K2HP-SAP), vary with age in healthy individuals and trends are gender-dependent. We evaluated 110 healthy volunteers (55 males) divided into five age subgroups (21-30, 31-40, 41-50, 51-60, and 61-70 yr). Each subgroup was formed by 22 subjects (11 males). HP series was extracted from electrocardiogram and SAP from finger arterial pressure at supine resting (REST) and during active standing (STAND). PhHP-SAP and K2HP-SAP functions were sampled in low-frequency (LF, from 0.04 to 0.15 Hz) and in high-frequency (HF, above 0.15 Hz) bands. Both at REST and during STAND PhHP-SAP(LF) showed a negative correlation with age regardless of gender even though values were more negative in women. This trend was shown to be compatible with a progressive increase of the baroreflex latency with age. At REST K2HP-SAP(LF) decreased with age regardless of gender, but during STAND the high values of K2HP-SAP(LF) were more preserved in men than women. At REST and during STAND the association of PhHP-SAP(HF) and K2HP-SAP(HF) with age was absent. The findings points to a greater instability of baroreflex control with age that seems to affect to a greater extent women than men. NEW & NOTEWORTHY Aging increases cardiac baroreflex latency and decreases the degree of cardiac baroreflex involvement in regulating cardiovascular variables. These trends are gender independent but lead to longer delays and asmaller degree of cardiac baroreflex involvement in women than in men, especially during active standing, with important implications on the tolerance to an orthostatic stressor.

8.
Clinics ; 73: e439, 2018. tab, graf
Artigo em Inglês | LILACS-Express | ID: biblio-974906

RESUMO

OBJECTIVE: The objective of this study was to investigate the interaction among the determinants of expiratory flow limitation (EFL), peak oxygen uptake (VO2peak), dysanapsis ratio (DR) and age during cycling at different intensities in young and middle-aged men. METHODS: Twenty-two (11 young and 11 middle-aged) men were assessed. Pulmonary function tests (DR), cardiopulmonary exercise tests (VO2peak) and two constant load tests (CLTs) at 75% (moderate intensity) and 125% (high intensity) of the gas exchange threshold were performed to assess EFL. EFL was classified using the percentage of EFL determined from both CLTs (mild: 5%-30%, moderate: 30%-50%, severe: >50%). RESULTS: Only the middle-aged group displayed EFL at both exercise intensities (p<0.05). However, the number of participants with EFL and the percentage of EFL were only associated with age during high-intensity exercise. CONCLUSIONS: There was no interaction between the determinants. However, age was the only factor that was related to the presence of EFL during exercise in the age groups studied.

9.
Auton Neurosci ; 208: 29-35, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28916152

RESUMO

PURPOSE: To carry out a systematic review to determine if inspiratory muscle training (IMT) promotes changes in cardiovascular autonomic responses in humans. METHODS: The methodology followed the PRISMA statement for reporting systematic review analysis. MEDLINE, PEDro, SCOPUS and PubMed electronic databases were searched from the inception to March 2017. The quality assessment was performed using a PEDro scale. The articles were included if: (1) primary objective was related to the effects of IMT on the cardiovascular autonomic nervous system, and (2) randomized clinical trials and quasi-experimental studies. Exclusion criteria were reviews, short communications, letters, case studies, guidelines, theses, dissertations, qualitative studies, scientific conference abstracts, studies on animals, non-English language articles and articles addressing other breathing techniques. Outcomes evaluated were measures of cardiovascular autonomic control, represented by heart rate variability (HRV) and blood pressure variability (BPV) indexes. RESULTS: The search identified 729 citations and a total of 6 studies were included. The results demonstrated that IMT performed at low intensities can chronically promote an increase in the parasympathetic modulation and/or reduction of sympathetic cardiac modulation in patients with diabetes, hypertension, chronic heart failure and gastroesophageal reflux, when assessed by HRV spectral analysis. However, there was no study which evaluated the effects of IMT on cardiovascular autonomic control assessed by BPV. CONCLUSIONS: IMT can promote benefits for cardiac autonomic control, however the heterogeneity of populations associated with different protocols, few studies reported in the literature and the lack of randomized controlled trials make the effects of IMT on cardiovascular autonomic control inconclusive.


Assuntos
Sistema Nervoso Autônomo/fisiologia , Exercícios Respiratórios , Inalação/fisiologia , Músculos Respiratórios/fisiologia , Humanos
10.
Physiol Meas ; 38(5): 940-958, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28079528

RESUMO

OBJECTIVE: We exploited a model-based Wiener-Granger causality method in the information domain for the evaluation of the transfer entropy (TE) and interaction TE (ITE), the latter taken as a measure of the net balance between redundancy and synergy, to describe the interactions between the spontaneous variability of heart period (HP) and systolic arterial pressure (SAP) and the effect of respiration (R) on both variables. APPROACH: Cardiac control was typified via the genuine TE from SAP to HP, that from R to HP, and the ITE from SAP and R to HP, while vascular control was characterized via the genuine TE from HP to SAP, that from R to SAP, and the ITE from HP and R to SAP. The approach was applied to study age-related modifications of cardiac and vascular controls in a cohort of 100 healthy humans (age from 21 to 70 years, 54 males) recorded at supine rest (REST) and during active standing (STAND). A surrogate approach was exploited to test the significance of the computed quantities. MAIN RESULTS: Trends of the genuine information transfer with age, already present in literature, were here confirmed. We originally found that: (i) at REST redundancy was predominant over synergy in both vascular and cardiac controls; (ii) the predominance of redundancy of the cardiac control was not affected by postural challenge, while STAND reduced redundancy of vascular control; (iii) the net redundancy of the cardiac control at REST gradually decreased with age, while that of vascular control remained stable; (iv) during STAND net redundancy of both cardiac and vascular controls was stable with age. SIGNIFICANCE: The study confirms the relevance of computing genuine information transfer in cardiovascular control analysis and stresses the importance of evaluating the ITE to quantify the degree of redundancy of physiological mechanisms operating to maintain cardiovascular homeostasis.


Assuntos
Envelhecimento/fisiologia , Pressão Arterial/fisiologia , Frequência Cardíaca/fisiologia , Respiração , Adulto , Idoso , Voluntários Saudáveis , Humanos , Pessoa de Meia-Idade , Modelos Cardiovasculares , Sístole/fisiologia , Adulto Jovem
11.
Int J Sports Med ; 38(2): 134-140, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27931053

RESUMO

The aim of the present study was to compare hemodynamic responses between blood flow-restricted resistance exercise (BFR-RE), high-intensity resistance exercise (HI-RE) and low-intensity resistance exercise (LI-RE) performed to muscular failure. 12 men (age: 20±3 years; body mass: 73.5±9 kg; height: 174±6 cm) performed 4 sets of leg press exercises using BFR-RE (30% of 1-RM), HI-RE (80% of 1-RM) and LI-RE (30% of 1-RM) protocols. Systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR), stroke volume (SV), cardiac output (CO) and total peripheral vascular resistance (TPR) were measured on a beat-to-beat continuous basis by a noninvasive photoplethysmographic arterial pressure device. The HI-RE and LI-RE showed higher values (P<0.05) in all of the sets than the BFR-RE for SBP, DBP, HR. Additionally, HI-RE showed higher SBP (4th set) and DBP (all sets) (P<0.05) values than the LI-RE. However, the SV, CO and TPR showed significantly greater values for LI-RE compared to HI-RE and BFR-RE (P<0.05). In conclusion, the results of this study indicate that the BFR-RE promotes a lower hemodynamic response compared to the HI-RE and LI-RE performed to muscular failure.


Assuntos
Hemodinâmica , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/fisiologia , Fluxo Sanguíneo Regional , Treinamento de Resistência , Adolescente , Pressão Sanguínea , Constrição , Estudos Cross-Over , Frequência Cardíaca , Humanos , Masculino , Força Muscular , Volume Sistólico , Resistência Vascular , Adulto Jovem
12.
Exp Physiol ; 101(5): 599-611, 2016 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-26935142

RESUMO

NEW FINDINGS: What is the central question of this study? This is the first study to evaluate and describe the cardiovascular responses during maximal expiratory pressure compared with the Valsalva manoeuvre, and whether those responses are similar. What is the main finding and its importance? This study showed that the duration of the manoeuvres appears to be responsible for the different physiological mechanisms involved in the cardiovascular responses to each manoeuvre and that the intensity of expiratory effort was related to the response in maximal expiratory pressure. These results are important to identify the risks to which subjects are exposed when performing these manoeuvres. The main purpose of this study was to compare the cardiovascular responses between the Valsalva manoeuvre (VM) and maximal expiratory pressure (MEP) and to evaluate the effect of age on these responses. Twenty-eight healthy men were evaluated and divided into two groups, younger (n = 15, 25 ± 5 years) and middle aged (n = 13, 50 ± 5 years), and they performed the VM and MEP measurement. The VM consisted of an expiratory effort (40 mmHg) against a manometer for 15 s, and the MEP was performed according to American Thoracic Society guidelines. The cardiovascular responses were analysed at rest, isotime (3 s), peak, nadir and recovery, and the cardiovascular variations (Δ) were calculated as peak or isotime minus resting values. For the statistical analysis, we used two-way ANOVA (P < 0.05). We observed that MEP and the VM generate similar changes in cardiac output (P > 0.05), but MEP presents higher values for mean arterial pressure (MAPPeak , MAPIsotime , ΔMAP and ΔMAPIsotime ) than those observed in the VM (P < 0.05). The execution time of the manoeuvres (VM ∼15 s and MEP ∼5 s) appears to be largely responsible for the activation of different physiological mechanisms involved in the cardiovascular control for each manoeuvre, and the intensity of expiratory effort is related to the higher response of MAP and peripheral vascular resistance (PVRIsotime and ΔPVRIsotime ) during MEP (P < 0.05). Moreover, it appears that age affects only the heart rate and PVR responses (P < 0.05), which were higher in the young and middle-aged group, respectively. Based on these findings, we can conclude that MEP and the VM do not generate similar cardiovascular responses, except for cardiac output.


Assuntos
Sistema Cardiovascular/fisiopatologia , Expiração/fisiologia , Manobra de Valsalva/fisiologia , Adulto , Pressão Sanguínea/fisiologia , Débito Cardíaco/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pressões Respiratórias Máximas/métodos , Pessoa de Meia-Idade , Respiração , Resistência Vascular/fisiologia
13.
Arq Bras Cardiol ; 104(6): 476-85, 2015 Jun.
Artigo em Inglês, Português | MEDLINE | ID: mdl-26131703

RESUMO

BACKGROUND: Circulatory power (CP) and ventilatory power (VP) are indices that have been used for the clinical evaluation of patients with heart failure; however, no study has evaluated these indices in patients with coronary artery disease (CAD) without heart failure. OBJECTIVE: To characterize both indices in patients with CAD compared with healthy controls. METHODS: Eighty-seven men [CAD group = 42 subjects and healthy control group (CG) = 45 subjects] aged 40-65 years were included. Cardiopulmonary exercise testing was performed on a treadmill and the following parameters were measured: 1) peak oxygen consumption (VO2), 2) peak heart rate (HR), 3) peak blood pressure (BP), 4) peak rate-pressure product (peak systolic HR x peak BP), 5) peak oxygen pulse (peak VO2/peak HR), 6) oxygen uptake efficiency (OUES), 7) carbon dioxide production efficiency (minute ventilation/carbon dioxide production slope), 8) CP (peak VO2 x peak systolic BP) and 9) VP (peak systolic BP/carbon dioxide production efficiency). RESULTS: The CAD group had significantly lower values for peak VO2 (p < 0.001), peak HR (p < 0.001), peak systolic BP (p < 0.001), peak rate-pressure product (p < 0.001), peak oxygen pulse (p = 0.008), OUES (p < 0.001), CP (p < 0.001), and VP (p < 0.001) and significantly higher values for peak diastolic BP (p = 0.004) and carbon dioxide production efficiency (p < 0.001) compared with CG. Stepwise regression analysis showed that CP was influenced by group (R2 = 0.44, p < 0.001) and VP was influenced by both group and number of vessels with stenosis after treatment (interaction effects: R2 = 0.46, p < 0.001). CONCLUSION: The indices CP and VP were lower in men with CAD than healthy controls.


Assuntos
Pressão Sanguínea/fisiologia , Doença da Artéria Coronariana/fisiopatologia , Teste de Esforço , Tolerância ao Exercício/fisiologia , Consumo de Oxigênio/fisiologia , Adulto , Idoso , Dióxido de Carbono/metabolismo , Estudos de Casos e Controles , Estudos Transversais , Exercício/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Testes de Função Respiratória , Estatísticas não Paramétricas , Fatores de Tempo
14.
Arq. bras. cardiol ; 104(6): 476-485, 06/2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-750695

RESUMO

Background: Circulatory power (CP) and ventilatory power (VP) are indices that have been used for the clinical evaluation of patients with heart failure; however, no study has evaluated these indices in patients with coronary artery disease (CAD) without heart failure. Objective: To characterize both indices in patients with CAD compared with healthy controls. Methods: Eighty-seven men [CAD group = 42 subjects and healthy control group (CG) = 45 subjects] aged 40–65 years were included. Cardiopulmonary exercise testing was performed on a treadmill and the following parameters were measured: 1) peak oxygen consumption (VO2), 2) peak heart rate (HR), 3) peak blood pressure (BP), 4) peak rate-pressure product (peak systolic HR x peak BP), 5) peak oxygen pulse (peak VO2/peak HR), 6) oxygen uptake efficiency (OUES), 7) carbon dioxide production efficiency (minute ventilation/carbon dioxide production slope), 8) CP (peak VO2 x peak systolic BP) and 9) VP (peak systolic BP/carbon dioxide production efficiency). Results: The CAD group had significantly lower values for peak VO2 (p < 0.001), peak HR (p < 0.001), peak systolic BP (p < 0.001), peak rate-pressure product (p < 0.001), peak oxygen pulse (p = 0.008), OUES (p < 0.001), CP (p < 0.001), and VP (p < 0.001) and significantly higher values for peak diastolic BP (p = 0.004) and carbon dioxide production efficiency (p < 0.001) compared with CG. Stepwise regression analysis showed that CP was influenced by group (R2 = 0.44, p < 0.001) and VP was influenced by both group and number of vessels with stenosis after treatment (interaction effects: R2 = 0.46, p < 0.001). Conclusion: The indices CP and VP were lower in men with CAD than healthy controls. .


Fundamento: Os índices da Potência Circulatória (PC) e Potência Ventilatória (PV) têm sido utilizados para avaliação clínica de pacientes com insuficiência cardíaca, mas nenhum estudo avaliou esses índices em pacientes com Doença Arterial Coronariana (DAC). Objetivo: Caracterizar ambos os índices em pacientes com DAC comparados a indivíduos saudáveis. Métodos: Oitenta e sete homens [grupo DAC = 42 sujeitos e, grupo controle (GC) = 45 sujeitos] com idade entre 45 e 65 anos foram incluídos. Um Teste de Exercício Cardiopulmonar (TECP) foi realizado em esteira e as seguintes variáveis foram obtidas: 1) consumo de oxigênio (VO2) pico; 2) Frequência Cardíaca (FC) pico; 3) Pressão Arterial (PA) pico; 4) duplo produto pico (PA sistólica pico x FC pico); 5) pulso de oxigênio pico (VO2 pico dividido pela FC pico); 6) eficiência ventilatória para o consumo de oxigênio (OUES); 7) eficiência ventilatória para a produção de dióxido de carbono (VE/VCO2 slope); 8) PC (VO2 pico x PA sistólica pico); e 9) PV (PA sistólica pico dividido pelo VE/VCO2 slope). Resultados: O grupo DAC apresentou valores significativamente menores das seguintes variáveis no pico do exercício: VO2 (p < 0,001), FC (p < 0,001), PA sistólica (p < 0,001), duplo produto (p < 0,001), pulso de oxigênio (p = 0,008), OUES (p < 0,001), PC (p < 0,001) e PV (p < 0,001), e valores significativamente maiores de PA diastólica (p = 0,004) e VE/VCO2 slope (p < 0,001) em relação ao GC. Uma análise de regressão pelo método stepwise mostrou que a PC foi influenciada pelo grupo (R2 = 0,44, p < 0,001) e a PV tanto pelo grupo quanto pelo número de vasos com estenose pós tratamento (efeito de interação: R2 = 0,46, p < 0,001). Conclusion: Os índices da PC e PV foram menores em homens com DAC comparados ao GC, podendo dessa forma ser utilizados na caracterização dessa população. .


Assuntos
Animais , Humanos , Óxido de Alumínio/toxicidade , Moléculas de Adesão Celular/metabolismo , Adesão Celular/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Células Cultivadas , Moléculas de Adesão Celular/genética , Relação Dose-Resposta a Droga , Selectina E/genética , Selectina E/metabolismo , Endotélio Vascular/metabolismo , Endotélio Vascular/ultraestrutura , Expressão Gênica/efeitos dos fármacos , Molécula 1 de Adesão Intercelular/genética , Molécula 1 de Adesão Intercelular/metabolismo , Microscopia Eletrônica de Transmissão/métodos , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Monócitos/ultraestrutura , Tamanho da Partícula , RNA Mensageiro/metabolismo , Suínos , Molécula 1 de Adesão de Célula Vascular/genética , Molécula 1 de Adesão de Célula Vascular/metabolismo
16.
PLoS One ; 9(2): e89463, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24586796

RESUMO

The proposed approach evaluates complexity of the cardiovascular control and causality among cardiovascular regulatory mechanisms from spontaneous variability of heart period (HP), systolic arterial pressure (SAP) and respiration (RESP). It relies on construction of a multivariate embedding space, optimization of the embedding dimension and a procedure allowing the selection of the components most suitable to form the multivariate embedding space. Moreover, it allows the comparison between linear model-based (MB) and nonlinear model-free (MF) techniques and between MF approaches exploiting local predictability (LP) and conditional entropy (CE). The framework was applied to study age-related modifications of complexity and causality in healthy humans in supine resting (REST) and during standing (STAND). We found that: 1) MF approaches are more efficient than the MB method when nonlinear components are present, while the reverse situation holds in presence of high dimensional embedding spaces; 2) the CE method is the least powerful in detecting age-related trends; 3) the association of HP complexity on age suggests an impairment of cardiac regulation and response to STAND; 4) the relation of SAP complexity on age indicates a gradual increase of sympathetic activity and a reduced responsiveness of vasomotor control to STAND; 5) the association from SAP to HP on age during STAND reveals a progressive inefficiency of baroreflex; 6) the reduced connection from HP to SAP with age might be linked to the progressive exploitation of Frank-Starling mechanism at REST and to the progressive increase of peripheral resistances during STAND; 7) at REST the diminished association from RESP to HP with age suggests a vagal withdrawal and a gradual uncoupling between respiratory activity and heart; 8) the weakened connection from RESP to SAP with age might be related to the progressive increase of left ventricular thickness and vascular stiffness and to the gradual decrease of respiratory sinus arrhythmia.


Assuntos
Pressão Arterial/fisiologia , Coração/fisiologia , Adulto , Fatores Etários , Idoso , Barorreflexo/fisiologia , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Modelos Cardiovasculares , Dinâmica não Linear , Postura/fisiologia , Respiração , Adulto Jovem
17.
Fisioter. Bras ; 13(6): 403-408, Nov.-Dez. 2012.
Artigo em Português | LILACS | ID: lil-766782

RESUMO

A avaliação da dispneia tem sido feita por meio de instrumentoscomo escala de Borg modificada, a escala de cores e a escala do MedicalResearch Council modificada (mMRC). O objetivo deste estudofoi correlacionar a frequência respiratória com a sensação de dispneia,através das escalas citadas, correlacioná-las entre si e verificar se ograu de alfabetização influenciou na resposta do paciente sobre asensação de dispneia. Para avaliar o esforço físico utilizou-se o testede caminhada de seis minutos. Este foi um estudo prospectivo,transversal e analítico-descritivo composto por 124 voluntárioscom diagnóstico de doença pulmonar. Para comparar as variáveiscategóricas entre os grupos foram utilizados os testes Qui-Quadradoe exato de Fisher. Para comparar as variáveis contínuas foi utilizadoo teste Kruskal-Wallis e para análise de correlação foi utilizado ocoeficiente de correlação de Spearman. A idade média foi de 55,9 (±13,08 anos), 14% eram analfabetos. Nos tempos de análise houvecorrelação positiva entre as escalas mMRC e Borg, r = 0,43, r = 0,61e r = 0,55. Entre as escalas mMRC e Cores, observou-se correlaçãonegativa. Concluiu-se que a frequência respiratória correlacionou-secom as três escalas. O grau de alfabetização não modificou a respostado paciente em relação à sensação de dispneia...


The evaluation of dyspnea has been measured using instrumentssuch as modified Borg Scale, the Colors Scale and modified Scaleof Medical Research Council (mMRC). The aim of this studywas to correlate the respiratory rate with dyspnea sensation usingthese scales, correlate them and identify if scholar level influenceson patients responses of dyspnea perception. The six-minute walkwas used to assess the physical effort. This was a prospective, cross--sectional and analytical descriptive study, which was composed of124 subjects with lung disease. The Chi-square and Fischer exact testwere used to compare the categorical variables among the groups.We used the Kruskal-Wallis test to compare the continuous variableand the Spearman correlation coefficient to analyze correlation. Themean age was 55.9 ± 13.08 years, 14% are illiterate. We observedpositive correlation between the mMRC and Borg scale, r = 0.43, r= 0.61 and r = 0.55. Among the mMRC and colors scale there wasa negative correlation. The results showed correlation between thescales mMRC, Borg and color Scale with respiratory rate and literacydid not change the patient’s response about dyspnea sensation...


Assuntos
Humanos , Dispneia , Fisioterapia
18.
Braz. j. phys. ther. (Impr.) ; 16(5): 406-413, Sept.-Oct. 2012. graf, tab
Artigo em Português | LILACS | ID: lil-654446

RESUMO

CONTEXTUALIZAÇÃO: A medida de pressão expiratória máxima (PEmáx) possui algumas contraindicações, pois acredita-se que as respostas obtidas nessa medida são similares às respostas encontradas na manobra de Valsalva (MV). OBJETIVOS: O objetivo principal é avaliar a resposta da frequência cardíaca (FC) durante a medida da PEmáx e da MV em jovens saudáveis, em diferentes posturas, para identificar se e em qual condição a PEmáx reproduz as respostas obtidas na MV e, adicionalmente, estimar o trabalho realizado nas manobras. MÉTODO: Doze jovens saudáveis foram avaliados, orientados e familiarizados com as manobras. A MV foi composta por um esforço expiratório (40 mmHg) durante 15 segundos contra um manômetro. A PEmáx foi executada segundo a American Thoracic Society. Ambas as medidas foram realizadas nas posturas supino e sentado. Para a análise da variação da frequência cardíaca (∆FC), índice de Valsalva (IV), índice da PEmáx (IPEmáx) e o trabalho estimado das manobras (Wtotal, Wisotime, Wtotal/∆FCtotal e Wisotime/∆FCisotime ), utilizou-se ANOVA two-way com post-hoc de Holm-Sidak (p<0,05). RESULTADOS: A ∆FC durante as manobras não foi influenciada pelas posturas; entretanto, durante a MV, a ∆FC e os valores do IV foram maiores (supino: 47±9 bpm, 2,3±0,2; sentado: 41±10 bpm, 2,0±0,2, respectivamente) do que a ∆FC e os valores de IPEmáx observados durante a PEmáx (supino: 23±8 bpm, 1,5±0,2; sentado 24±8 bpm, 1,6±0,3, respectivamente) (p<0,001). Os trabalhos estimados das manobras foram estatisticamente diferentes (p<0,001) entre elas, exceto para o Wtotal/∆FC. CONCLUSÕES: Nas condições estudadas, a PEmáx não reproduz as respostas da FC observadas durante a MV em jovens saudáveis.


BACKGROUND: The measure of the maximal expiratory pressure (MEP) has some contraindications, as it is believed that the responses obtained in this measure are similar to the Valsalva maneuver (VM). OBJECTIVE: The main purpose of this study was to evaluate the heart rate responses (HR) during the MEP and the VM measures in healthy young men into different postures aiming to identify whether and in which situation the MEP reproduces the responses obtained in the VM. Additionally we aim to estimate the workload realized during the maneuvers. METHOD: Twelve healthy young men were evaluated, instructed and familiarized with the maneuvers. The VM was characterized by an expiratory effort (40 mmHg) against a manometer for 15 seconds. The MEP measure has been performed according to the American Thoracic Society. Both measures were performed at sitting and supine positions. ANOVA two-way with Holm-Sidak post-hoc test (p<0.05) was used to analyse the heart rate variation (∆HR); Valsalva index (VI); MEP index (MEPI), and the estimated workload of the maneuvers (Wtotal, Wisotime, Wtotal/∆HRtotal and Wisotime/∆HRisotime ). RESULTS: The ∆HR during the maneuvers was not influenced by the supine and sitting positions. However, the ∆HR during the VM and VI were higher (supine: 47±9 bpm, 2.3±0.2; sitting: 41±10 bpm, 2.0±0.2, respectively) than ∆HR during the MEP and MEPI values (supine: 23±8 bpm, 1.5±0.2; sitting 24±8 bpm, 1.6±0.3, respectively) (p<0.001). The estimated workload of the maneuvers was statistically different (p<0.001) between the maneuvers, except to Wtotal/∆HR. Conclusions: In the studied conditions the MEP does not reproduces the HR response observed in the VM in healthy young men.


Assuntos
Adulto , Humanos , Masculino , Adulto Jovem , Frequência Cardíaca , Manobra de Valsalva , Postura , Mecânica Respiratória
19.
Rev Bras Fisioter ; 16(5): 406-13, 2012 Sep-Oct.
Artigo em Inglês, Português | MEDLINE | ID: mdl-22983214

RESUMO

BACKGROUND: The measure of the maximal expiratory pressure (MEP) has some contraindications, as it is believed that the responses obtained in this measure are similar to the Valsalva maneuver (VM). OBJECTIVE: The main purpose of this study was to evaluate the heart rate responses (HR) during the MEP and the VM measures in healthy young men into different postures aiming to identify whether and in which situation the MEP reproduces the responses obtained in the VM. Additionally we aim to estimate the workload realized during the maneuvers. METHOD: Twelve healthy young men were evaluated, instructed and familiarized with the maneuvers. The VM was characterized by an expiratory effort (40 mmHg) against a manometer for 15 seconds. The MEP measure has been performed according to the American Thoracic Society. Both measures were performed at sitting and supine positions. ANOVA two-way with Holm-Sidak post-hoc test (p<0.05) was used to analyse the heart rate variation (∆HR); Valsalva index (VI); MEP index (MEPI), and the estimated workload of the maneuvers (Wtotal, Wisotime, Wtotal/∆HRtotal and Wisotime/∆HRisotime ). RESULTS: The ∆HR during the maneuvers was not influenced by the supine and sitting positions. However, the ∆HR during the VM and VI were higher (supine: 47±9 bpm, 2.3±0.2; sitting: 41±10 bpm, 2.0±0.2, respectively) than ∆HR during the MEP and MEPI values (supine: 23±8 bpm, 1.5±0.2; sitting 24±8 bpm, 1.6±0.3, respectively) (p<0.001). The estimated workload of the maneuvers was statistically different (p<0.001) between the maneuvers, except to Wtotal/∆HR. CONCLUSIONS: In the studied conditions the MEP does not reproduces the HR response observed in the VM in healthy young men.


Assuntos
Frequência Cardíaca , Manobra de Valsalva , Adulto , Humanos , Masculino , Postura , Mecânica Respiratória , Adulto Jovem
20.
J. Health Sci. Inst ; 30(3)jul.-set. 2012. graf, tab
Artigo em Português | LILACS | ID: lil-670574

RESUMO

Objetivo - Avaliar e comparar a distância percorrida pelos diferentes distúrbios pulmonares com a predita por Enright-Sherrill, assim como a velocidade média durante o teste de caminhada de seis minutos (TC6). Além de verificar se a idade, o índice de massa corporal (IMC), os índices espirométricos e a velocidade média poderiam influenciar na resposta do TC6. Métodos - Participaram 124 indivíduos com diagnóstico de doenças pulmonares, que foram divididos a partir da espirometria em três grupos: obstrutivo, restritivo e misto. Foram avaliados os dados antropométricos e pessoais destes, e depois encaminhados para realizar o TC6 segundo a ATS. Resultados - Observou-se diferença estatística (p<0,001) entre a distância percorrida pelos três grupos durante o TC6 com a predita por Enright-Sherrill. No entanto, quando avaliada a distância entre os grupos não foi observada diferença estatística (p>0,05). Em relação à velocidade média não houve diferença entre os grupos (p=0,666). Contudo, observou-se que esta variável é influenciada pelo tempo (p<0,001). Também se observou correlação entre a idade (r=-0,29) e a velocidade média (r=0,93) com a distância percorrida. Já a distância predita, apresentou correlação com o IMC (r=-0,84), idade (r=-0,36) e velocidade média (r=0,37). Conclusões - Quanto ao distúbioo pulmonar, não houve interferência deste sobre a distância percorrida e predita no TC6, e sobre a velocidade média. No entanto, observou-se que a idade, o IMC e a velocidade média são os responsáveis pela resposta do TC6.


Objective -To evaluate and compare the six-minute walking distance (6MWD) in different lung disorders with the predicted by Enright-Sherrill; as well as the average speed during the six-minute walk test (6MWT). Beyond this, check if age, body-mass index, lung function and average speed can influence the response of 6MWT. Methods - This study included 124 subjects with lung diseases, which have been divided from the lung functions results in three groups: obstructive, restrictive and mixed. The anthropometrics and personal data was evaluated, and then, they were sent to perform the 6MWT, according to ATS. Results - We observed statistical difference (p<0.001) between the 6MWD obtained by the groups and the predicted by Enright-Sherrill. However, we didn't observed statistical difference among the groups, when we evaluate the 6MWD. In relation to average speed, we didn't find difference among groups (p=0.666). However, we observed that the time influenced this variable (p<0.001). Also, we observed correlation between the age (r=-0.29) and average speed (r=0.93) with the 6MWD. Already, the predicted 6MWD had correlation with body-mass index (r=-0.84), age (r=-0.36) and average speed (r=0.37). Conclusions - As to lung disorders, there was no interference about six-minute walk distance and predicted 6MWD, as well as about average speed. However, has been observed that age, body-mass index and average speed are the responsible for the response of 6MWT.


Assuntos
Humanos , Masculino , Feminino , Espirometria/estatística & dados numéricos , Espirometria , Doença Pulmonar Obstrutiva Crônica , Fibrose Pulmonar , Pneumopatias/diagnóstico , Pneumopatias/patologia , Pneumopatias/prevenção & controle , Teste de Esforço/instrumentação , Teste de Esforço/métodos
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