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Registros recuperados: 30 | |
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Oliveira,P.F.; Dias da Silva,V.J.; Salgado,M.C.O.; Fazan Jr.,R.; Aguiar,C.A.; Salgado,H.C.. |
The aim of the present study was to evaluate the effect of amiodarone on mean arterial pressure (MAP), heart rate (HR), baroreflex, Bezold-Jarisch, and peripheral chemoreflex in normotensive and chronic one-kidney, one-clip (1K1C) hypertensive rats (N = 9 to 11 rats in each group). Amiodarone (50 mg/kg, iv) elicited hypotension and bradycardia in normotensive (-10 ± 1 mmHg, -57 ± 6 bpm) and hypertensive rats (-37 ± 7 mmHg, -39 ± 19 bpm). The baroreflex index (deltaHR/deltaMAP) was significantly attenuated by amiodarone in both normotensive (-0.61 ± 0.12 vs -1.47 ± 0.14 bpm/mmHg for reflex bradycardia and -1.15 ± 0.19 vs -2.63 ± 0.26 bpm/mmHg for reflex tachycardia) and hypertensive rats (-0.26 ± 0.05 vs -0.72 ± 0.16 bpm/mmHg for reflex bradycardia and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amiodarone; Baroreflex; Bezold-Jarisch reflex; Chemoreflex; Autonomic nervous system; 1K1C hypertension. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000600020 |
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Buto,M.S.S.; Catai,A.M.; Vassimon-Barroso,V.; Gois,M.O.; Porta,A.; Takahashi,A.C.M.. |
Frailty is related to a decrease in the physiological reserves, which causes difficulties in maintaining homeostasis. An example of physiological mechanisms for cardiovascular homeostasis is the baroreflex. The aim of this study was to compare baroreflex among frail, prefrail, and nonfrail individuals, in supine and orthostatic positions. Community-dwelling older adults were evaluated and categorized into frail, prefrail, or nonfrail groups, according to frailty phenotype. The RR interval (RRi) and systolic blood pressure (SBP) series were recorded for 15 min in the supine and 15 min in the orthostatic positions. Mean and variance of RRi and SBP, and baroreflex evaluated by phase, gain (α), and coherence (K2) were determined. A two-way repeated measures... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Baroreflex; Autonomic nervous system; Aging; Frailty. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2019000400602 |
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Machado,H.G.; Simões,R.P.; Mendes,R.G.; Castello,V.; Di Thommazo,L.; Almeida,L.B.; Lopes,S.L.B.; Catai,A.M.; Borghi-Silva,A.. |
The purpose of this study was to investigate the behavior of heart rate (HR) and HR variability (HRV) during different loads of resistance exercise (incline bench press) in patients with coronary artery disease (CAD) and healthy sedentary controls. Ten healthy men (65 ± 1.2 years, control group, CG) and 10 men with clinically stable CAD (66 ± 2.4 years, CADG) were recruited. A discontinuous progressive protocol was applied with an initial load of 10% of the maximum load achieved in the 1RM (1 repetition maximum) with increases of 10% until 30% 1RM was reached, which was followed by subsequent increases of 5% 1RM until exhaustion. HRV was analyzed by linear and non-linear methods. There was a significant reduction in rMSSD (CG: 20 ± 2 to 11 ± 3 ms; CADG: 19... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dynamic resistance exercise; Coronary artery disease; Heart rate variability; Autonomic nervous system; Upper limb exercise. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011001200012 |
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Chacon-Mikahil,M.P.T.; Forti,V.A.M.; Catai,A.M.; Szrajer,J.S.; Golfetti,R.; Martins,L.E.B.; Lima-Filho,E.C.; Wanderley,J.S.; Marin-Neto,J.A.; Maciel,B.C.; Gallo-Jr.,L.. |
We investigated the effects of aerobic training on the efferent autonomic control of heart rate (HR) during dynamic exercise in middle-aged men, eight of whom underwent exercise training (T) while the other seven continued their sedentary (S) life style. The training was conducted over 10 months (three 1-h sessions/week on a field track at 70-85% of the peak HR). The contribution of sympathetic and parasympathetic exercise tachycardia was determined in terms of differences in the time constant effects on the HR response obtained using a discontinuous protocol (4-min tests at 25, 50, 100 and 125 watts on a cycle ergometer), and a continuous protocol (25 watts/min until exhaustion) allowed the quantification of the parameters (anaerobic threshold, VO2 AT;... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sympathetic modulation of heart rate; Dynamic exercise; Aerobic training; Autonomic nervous system; Anaerobic threshold; Middle-aged men. |
Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000500016 |
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Bianchim,M.S.; Sperandio,E.F.; Martinhão,G.S.; Matheus,A.C.; Lauria,V.T.; da Silva,R.P.; Spadari,R.C.; Gagliardi,A.R.T.; Arantes,R.L.; Romiti,M.; Dourado,V.Z.. |
The autonomic nervous system maintains homeostasis, which is the state of balance in the body. That balance can be determined simply and noninvasively by evaluating heart rate variability (HRV). However, independently of autonomic control of the heart, HRV can be influenced by other factors, such as respiratory parameters. Little is known about the relationship between HRV and spirometric indices. In this study, our objective was to determine whether HRV correlates with spirometric indices in adults without cardiopulmonary disease, considering the main confounders (e.g., smoking and physical inactivity). In a sample of 119 asymptomatic adults (age 20-80 years), we evaluated forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1). We... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Autonomic nervous system; Spirometry; Smoking. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2016000300702 |
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Fellet,A.L.; Di Verniero,C.; Arza,P.; Tomat,A.; Varela,A.; Arranz,C.; Balaszczuk,A.M.. |
Acute nitric oxide synthase inhibition with N G-nitro-L-arginine methyl ester (L-NAME) on chronotropic and pressor responses was studied in anesthetized intact rats and rats submitted to partial and complete autonomic blockade. Blood pressure and heart rate were monitored intra-arterially. Intravenous L-NAME injection (7.5 mg/kg) elicited the same hypertensive response in intact rats and in rats with partial (ganglionic and parasympathetic blockade) and complete autonomic blockade (38 ± 3, 55 ± 6, 54 ± 5, 45 ± 5 mmHg, respectively; N = 9, P = NS). L-NAME-induced bradycardia at the time when blood pressure reached the peak plateau was similar in intact rats and in rats with partial autonomic blockade (43 ± 8, 38 ± 5, 46 ± 6 bpm, respectively; N = 9, P =... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nitric oxide; Nitric oxide synthase; Autonomic nervous system; Heart rate; Heart. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000500015 |
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Melo,R.C.; Santos,M.D.B.; Silva,E.; Quitério,R.J.; Moreno,M.A.; Reis,M.S.; Verzola,I.A.; Oliveira,L.; Martins,L.E.B.; Gallo-Junior,L.; Catai,A.M.. |
The effects of the aging process and an active life-style on the autonomic control of heart rate (HR) were investigated in nine young sedentary (YS, 23 ± 2.4 years), 16 young active (YA, 22 ± 2.1 years), 8 older sedentary (OS, 63 ± 2.4 years) and 8 older active (OA, 61 ± 1.1 years) healthy men. Electrocardiogram was continuously recorded for 15 min at rest and for 4 min in the deep breathing test, with a breath rate of 5 to 6 cycles/min in the supine position. Resting HR and RR intervals were analyzed by time (RMSSD index) and frequency domain methods. The power spectral components are reported in normalized units (nu) at low (LF) and high (HF) frequency, and as the LF/HF ratio. The deep breathing test was analyzed by the respiratory sinus arrhythmia... |
Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Heart rate variability; Respiratory sinus arrhythmia; Autonomic nervous system; Aging process; Aerobic exercise. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000900007 |
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Pantoni,C.B.F.; Di Thommazo,L.; Mendes,R.G.; Catai,A.M.; Luzzi,S.; Amaral Neto,O.; Borghi-Silva,A.. |
The application of continuous positive airway pressure (CPAP) produces important hemodynamic alterations, which can influence breathing pattern (BP) and heart rate variability (HRV). The aim of this study was to evaluate the effects of different levels of CPAP on postoperative BP and HRV after coronary artery bypass grafting (CABG) surgery and the impact of CABG surgery on these variables. Eighteen patients undergoing CABG were evaluated postoperatively during spontaneous breathing (SB) and application of four levels of CPAP applied in random order: sham (3 cmH2O), 5 cmH2O, 8 cmH2O, and 12 cmH2O. HRV was analyzed in time and frequency domains and by nonlinear methods and BP was analyzed in different variables (breathing frequency, inspiratory tidal volume,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Continuous positive airway pressure; Cardiovascular system; Autonomic nervous system; Ventilation; Coronary artery bypass. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000100006 |
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Ribeiro,T.F.; Azevedo,G.D.; Crescêncio,J.C.; Marães,V.R.F.S.; Papa,V.; Catai,A.M.; Verzola,R.M.M.; Oliveira,L.; Silva de Sá,M.F.; Gallo Jr.,L.; Silva,E.. |
The aim of the present study was to compare the modulation of heart rate in a group of postmenopausal women to that of a group of young women under resting conditions on the basis of R-R interval variability. Ten healthy postmenopausal women (mean ± SD, 58.3 ± 6.8 years) and 10 healthy young women (mean ± SD, 21.6 ± 0.82 years) were submitted to a control resting electrocardiogram (ECG) in the supine and sitting positions over a period of 6 min. The ECG was obtained from a one-channel heart monitor at the CM5 lead and processed and stored using an analog to digital converter connected to a microcomputer. R-R intervals were calculated on a beat-to-beat basis from the ECG recording in real time using a signal-processing software. Heart rate variability (HRV)... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Heart rate variability; Menopause; Autonomic nervous system; Time domain indexes. |
Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000700006 |
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Chagas,M. A.; Babinski,M. A.; Abidu-Figueiredo,M.; Costa,W. S.. |
The otic ganglion is a cranial component of the parasympathetic division of the autonomic nervous system (ANS). Similar to other parasympathetic ganglia, otic ganglion presents multipolar neurons that are completely surrounded by satellite cells and intercellular substance as well, which allow us to use this ganglion as a good experimental model for studying the relationship neuron / extracellular matrix. We have studied rat otic ganglion in 10 animals through light microscopy. After routine histological methods, 5 µm sections were obtained and coloured by Gomori`s trichrome, periodic acid-Schiff (PAS), Alcian Blue pH 2.5 and pH1.0, acetylation + PAS, acetylation + deacetylation + PAS, acid hydrolysis + PAS, phenylhydrazine + PAS and thiosemicarbazide +... |
Tipo: Journal article |
Palavras-chave: Rat; Otic ganglion; Autonomic nervous system; Histochemistry. |
Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022006000100015 |
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da L. Goulart,C.; San Martin,E.A.; Mansour,K.M.K.; Schneiders,P.B.; da Silva,A.L.G.. |
The aim of this study was to evaluate the effect of expiratory positive airway pressure (EPAP) on heart rate variability (HRV) indices at rest and during 6-min walk test (6MWT) in chronic obstructive pulmonary disease (COPD) patients. Fifteen moderate to severe COPD patients were randomized and evaluated with and without (Non-EPAP) a 5 cmH2O EPAP device. Respiratory rate (RR) was collected at rest (5 min), during the 6MWT (5 min), and at recovery (5 min). Indices of HRV were computed in the time domain, in the frequency domain, and nonlinear analysis. For EPAP and Non-EPAP during the 6MWT, we found an increased mean heart rate (HR) (P=0.001; P=0.001) while mean RR (P=0.001; P=0.015) and RR tri index decreased (P=0.006; P=0.028). Peripheral oxygen... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Autonomic nervous system; HRV; COPD; Positive-pressure respiration; Exercise test. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2018000600605 |
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Kunz,V.C.; Borges,E.N.; Coelho,R.C.; Gubolino,L.A.; Martins,L.E.B.; Silva,E.. |
The objectives of this study were to evaluate and compare the use of linear and nonlinear methods for analysis of heart rate variability (HRV) in healthy subjects and in patients after acute myocardial infarction (AMI). Heart rate (HR) was recorded for 15 min in the supine position in 10 patients with AMI taking β-blockers (aged 57 ± 9 years) and in 11 healthy subjects (aged 53 ± 4 years). HRV was analyzed in the time domain (RMSSD and RMSM), the frequency domain using low- and high-frequency bands in normalized units (nu; LFnu and HFnu) and the LF/HF ratio and approximate entropy (ApEn) were determined. There was a correlation (P < 0.05) of RMSSD, RMSM, LFnu, HFnu, and the LF/HF ratio index with the ApEn of the AMI group on the 2nd (r = 0.87, 0.65,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Myocardial infarction; Heart rate variability; Autonomic nervous system; Spectral analysis; Nonlinear dynamics. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000500011 |
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Registros recuperados: 30 | |
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