caa a22 4500 463157907 CHVBK 20180406164739.0 cr unu---uuuuu 170326e20071201xx s 000 0 eng 10.1007/s10286-007-0448-6 doi (NATIONALLICENCE)springer-10.1007/s10286-007-0448-6 Sympathetic nerve activity restrains reflex vasodilatation in heart failure [Elektronische Daten] [Maria Alves, Maria Rondon, Amilton Santos, Rodrigo Dias, Antonio Barretto, Eduardo Krieger, Holly Middlekauff, Carlos Negrão] Background: Blunted reflex muscle vasodilatory response during exercise in heart failure (HF) patients may be secondary to augmented vasoconstriction. We tested the hypothesis that the exaggerated sympathetic nerve activity restrains the reflex muscle vasodilatation during exercise in HF patients. Methods: We studied the reflex vasodilatory response (plethysmography) during 3min static handgrip exercise at 30% maximal voluntary contraction in 10 advanced HF patients (45±3year, NYHA Functional Class III/IV) and 10 age-matched normal controls (NC, 40±3year, P=0.23) during intra-arterial infusion of: (1) saline control; and (2) alpha-adrenergic blocker (phentolamine). Results: Baseline forearm vascular conductance (FVC) was lower in HF patients than in NC (2.07±0.2 vs. 4.26±0.6units, respectively; P=0.002). FVC responses during exercise increased significantly in NC, but not in HF patients (delta changes: 1.05±0.4 vs. 0.05±0.2 units, respectively). Phentolamine significantly increased resting FVC in HF patients (from 2.07±0.2 to 5.74±0.7 units, P=0.00004) and restored reflex vasodilatory responses during exercise (delta changes: from 0.05±0.2 to 1.82±0.9 units) eliminating the difference in FVC between both groups. Conclusions: The blunted reflex muscle vasodilatory response during exercise in advanced HF patients is, at least in part, due to the increase in sympathetic nerve activity. Springer, 2007 forearm vascular conductance nationallicence handgrip exercise nationallicence alpha-adrenergic blockade nationallicence heart failure nationallicence Alves Maria Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil aut Rondon Maria Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil aut Santos Amilton Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil aut Dias Rodrigo Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil aut Barretto Antonio Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil aut Krieger Eduardo Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil aut Middlekauff Holly Dept. of Cardiology, University of California, Medical School, Los Angeles, CA, USA aut Negrão Carlos Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil aut https://doi.org/10.1007/s10286-007-0448-6 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10286-007-0448-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Alves Maria Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil aut NATIONALLICENCE 700 1- Rondon Maria Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil aut NATIONALLICENCE 700 1- Santos Amilton Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil aut NATIONALLICENCE 700 1- Dias Rodrigo Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil aut NATIONALLICENCE 700 1- Barretto Antonio Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil aut NATIONALLICENCE 700 1- Krieger Eduardo Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil aut NATIONALLICENCE 700 1- Middlekauff Holly Dept. of Cardiology, University of California, Medical School, Los Angeles, CA, USA aut NATIONALLICENCE 700 1- Negrão Carlos Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer