AJP - Heart Calcium Transients and Cell-Sarcomere
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
 QUICK SEARCH:   [advanced]


     


Am J Physiol Heart Circ Physiol (March 18, 2005). doi:10.1152/ajpheart.01240.2004
This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
289/2/H593    most recent
01240.2004v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Santos, A. C
Right arrow Articles by Negrao, C. E
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Santos, A. C
Right arrow Articles by Negrao, C. E
Submitted on December 8, 2004
Accepted on March 11, 2005

Sympathetic Activation Restrains Endothelial-Mediated Muscle Vasodilatation in Heart Failure Patients

Amilton C Santos1, Maria Janieire N Alves2, Maria Urbana P Rondon2, Antonio Carlos P Barretto2, Holly R Middlekauff3, and Carlos E Negrao4*

1 Unit of Cardiovascular Rehabilitation and Exercise Physiology, Heart Institute (InCor), University of Sao Paulo Medical School, Sao Paulo, SP, Brazil; Department of Physiology and Biophysics, Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo, SP, Brazil
2 Unit of Cardiovascular Rehabilitation and Exercise Physiology, Heart Institute (InCor), University of Sao Paulo Medical School, Sao Paulo, SP, Brazil
3 Department of Cardiology, University of California Los Angeles, Los Angeles, CA, USA
4 Unit of Cardiovascular Rehabilitation and Exercise Physiology, Heart Institute (InCor), University of Sao Paulo Medical School, Sao Paulo, SP, Brazil; School of Physical Education and Sport, University of Sao Paulo, Sao Paulo, SP, Brazil

* To whom correspondence should be addressed. E-mail: cndnegrao{at}incor.usp.br.

Although the vasodilatory response during mental stress is blunted in heart failure, the mechanisms underlying this phenomenon are not fully understood. We tested the hypothesis that sympathetic activity limits the endothelial-dependent vasodilatation during mental stress in chronic heart failure (HF) patients. Twenty-one HF patients (age 45 ± 2 years, Functional Class III-IV, NYHA), and 22 age-matched normal controls (NC, age 42 ± 2 years, P=0.13) were studied at rest and during 4 minutes of Stroop color word test with brachial intra-arterial saline, acetylcholine (endothelial-dependent), phentolamine (alpha-blocker), and phentolamine plus acetylcholine infusion. Forearm blood flow was measured by venous occlusion plethysmography. Baseline forearm vascular conductance (FVC) was significantly lower in HF patients (2.18 ± 0.12 vs. 3.66 ± 0.22 units, P=0.001). During mental stress with saline, the changes in FVC were significantly blunted in HF patients when compared with NC (0.92 ± 0.20 vs. 2.13 ± 0.39 units, P=0.001). In HF, the vasodilatation with acetylcholine was similar to saline control and significantly lower than in NC. In HF patients, phentolamine significantly increased FVC responses (1.16 ± 0.20 vs. 2.09 ± 0.29 units, P=0.001), and the difference between HF patients and NC tended to decrease (2.09 ±0.29 vs. 3.61 ± 0.74 units, P=0.052). The vasodilatation with phentolamine plus acetylcholine was similar between HF and NC (4.23 ± 0.73 vs. 4.76 ± 1.03 units, P=0.84). In conclusion, sympathetic activation mediates the blunted muscle endothelially-mediated vasodilatation during mental stress in HF patients.







HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Visit Other APS Journals Online
Copyright © 1977 by the American Physiological Society.