Exercise training prevents the deterioration in the arterial baroreflex control of sympathetic nerve activity in chronic heart failure patients

Date
2015-05-01Author
Groehs, Raphaela Vilar
Toschi-Dias, Edgar
Antunes-Correa, Ligia de Moraes
Trevizan, Patricia Fernandes
Rondon, Maria Urbana Pinto Brandão
Oliveira, Patricia
Alves, Maria Janieire de Nazaré Nunes
Almeida, Dirceu Rodrigues de [UNIFESP]
Middlekauff, Holly R.
Negrao, Carlos Eduardo
Type
ArtigoISSN
0363-6135Is part of
American Journal of Physiology-heart and Circulatory PhysiologyDOI
10.1152/ajpheart.00723.2014Metadata
Show full item recordAbstract
Arterial baroreflex control of muscle sympathetic nerve activity (ABRMSNA) is impaired in chronic systolic heart failure (CHF). the purpose of the study was to test the hypothesis that exercise training would improve the gain and reduce the time delay of ABRMSNA in CHF patients. Twenty-six CHF patients, New York Heart Association Functional Class II-III, EF <= 40%, peak (V) over dot O-2 <= 20 ml.kg(-1).min(-1) were divided into two groups: untrained (UT, n = 13, 57 +/- 3 years) and exercise trained (ET, n = 13, 49 +/- 3 years). Muscle sympathetic nerve activity (MSNA) was directly recorded by microneurography technique. Arterial pressure was measured on a beat-to-beat basis. Time series of MSNA and systolic arterial pressure were analyzed by autoregressive spectral analysis. the gain and time delay of ABRMSNA was obtained by bivariate autoregressive analysis. Exercise training was performed on a cycle ergometer at moderate intensity, three 60-min sessions per week for 16 wk. Baseline MSNA, gain and time delay of ABRMSNA, and low frequency of MSNA (LFMSNA) to high-frequency ratio (HFMSNA) (LFMSNA/HFMSNA) were similar between groups. ET significantly decreased MSNA. MSNA was unchanged in the UT patients. the gain and time delay of ABRMSNA were unchanged in the ET patients. in contrast, the gain of ABRMSNA was significantly reduced [3.5 +/- 0.7 vs. 1.8 +/- 0.2, arbitrary units (au)/mmHg, P = 0.04] and the time delay of ABRMSNA was significantly increased (4.6 +/- 0.8 vs. 7.9 +/- 1.0 s, P = 0.05) in the UT patients. LFMSNA-to-HFMSNA ratio tended to be lower in the ET patients (P < 0.08). Exercise training prevents the deterioration of ABRMSNA in CHF patients.
Citation
American Journal of Physiology-heart and Circulatory Physiology. Bethesda: Amer Physiological Soc, v. 308, n. 9, p. H1096-H1102, 2015.Sponsorship
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação Zerbini
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
National Heart, Lung, and Blood Institute
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