Abnormal neurovascular control during exercise is linked to heart failure severity
Unit of 1 Cardiovascular Rehabilitation and Exercise Physiology, 2 Hypertension, and 4 General Clinic of Cardiopathies, 3 School of Physical Education and Sports, InCor-Heart Institute, University of São Paulo Medical School, São Paulo, CEP 05403-000, Brazil; and 5 Department of Cardiology, Uni...
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Published in | American journal of physiology. Heart and circulatory physiology Vol. 280; no. 3; pp. H1286 - H1292 |
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Main Authors | , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
01.03.2001
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Subjects | |
Online Access | Get full text |
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Summary: | Unit of 1 Cardiovascular Rehabilitation and Exercise
Physiology, 2 Hypertension, and 4 General Clinic of
Cardiopathies, 3 School of Physical Education and Sports,
InCor-Heart Institute, University of São Paulo Medical School,
São Paulo, CEP 05403-000, Brazil; and
5 Department of Cardiology, University of California Medical
School, Los Angeles, California 90095
The purpose of this study was to determine if
abnormalities of sympathetic neural and vascular control are present in
mild and/or severe heart failure (HF) and to determine the underlying afferent mechanisms. Patients with severe HF, mild HF, and age-matched controls were studied. Muscle sympathetic nerve activity (MSNA) and
forearm vascular resistance (FVR) in the nonexercising arm were
measured during mild and moderate static handgrip. MSNA during moderate
handgrip was higher at baseline and throughout exercise in severe HF
vs. mild HF (peak MSNA 67 ± 3 vs. 54 ± 3 bursts/min, P < 0.0001) and higher in mild HF vs. controls (33 ± 3 bursts/min, P < 0.0001), but the change in MSNA was
not different between the groups. The change in FVR was not
significantly different between the three groups during static
exercise. During isolation of muscle metaboreceptors, MSNA and blood
pressure remained elevated in normal controls and mild HF but not in
severe HF. During mild handgrip, the increase in MSNA was exaggerated
in severe HF vs. controls and mild HF, in whom MSNA did not increase.
In summary, the increase in MSNA during static exercise in severe HF
appears to be attributable to exaggerated central command or muscle
mechanoreceptor control, not muscle metaboreceptor control.
autonomic nervous system |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0363-6135 1522-1539 |
DOI: | 10.1152/ajpheart.2001.280.3.h1286 |