Skip Navigation

Cardiovascular Research 1998 40(2):410-417; doi:10.1016/S0008-6363(98)00184-9
© 1998 by European Society of Cardiology
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow E-letters: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
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 Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Bellamy, M. F
Right arrow Articles by Henderson, A. H
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bellamy, M. F
Right arrow Articles by Henderson, A. H
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Copyright © 1998, European Society of Cardiology

Syndrome X and endothelial dysfunction

Michael F Bellamya, Jonathan Goodfellowa, Ann C Tweddela, Frank D.J Dunstanc,1, Malcolm J Lewisb and Andrew H Hendersona,*

aDepartment of Cardiology, University of Wales College of Medicine, Heath Park, Cardiff CF4 4XN, UK
bDepartment of Pharmacology, Therapeutics and Toxicology, University of Wales College of Medicine, Heath Park, Cardiff CF4 4XN, UK
cDepartment of Medical Statistics and Computing, University of Wales College of Medicine, Heath Park, Cardiff CF4 4XN, UK

* Corresponding author. Tel.: +44-1222-744-430; Fax: +44-1222-743-500; E-mail: simonsw@cf.ac.uk

Objective: Syndrome X (angina, normal coronary arteriogram and positive exercise test) remains an enigma with unexplained features and apparent conflicts of evidence. The present study addressed whether (i) the Syndrome is characterised by generalised flow-related endothelial dysfunction, (ii) myocardial thallium201 defects reflect myocardial or microvascular dysfunction, (iii) endothelial dysfunction and its consequences can be improved by oral L-arginine. Methods: Flow-mediated brachial artery dilatation was measured by ultrasonic ‘wall-tracking’ in 7 Syndrome X patients, further characterised as having thallium201 defects and no known cause of endothelial dysfunction, and a normal control group. Syndrome X patients entered a 4-week randomised double-blind placebo-controlled cross-over trial of oral L-arginine (7 g twice daily), with brachial artery studies, exercise tests and technetium99 tetrafosmin scans. Results: Flow-mediated dilatation was absent in Syndrome X vs. normal. Stress technetium99 tetrafosmin and thallium201 scans showed similar defects. Flow-mediated dilatation, symptom-limited exercise duration and peak oxygen consumption (VO2 max) were increased but rate-pressure-product (RPP) and radionuclide defects were unchanged after L-arginine vs. placebo. Conclusions: The study supports coronary microvascular rather than myocardial dysfunction and shows loss of flow-mediated dilatation in systemic arteries. Oral L-arginine improved flow-mediated dilatation, exercise capacity and VO2 max (by ca. 17%) despite unchanged RPP. The findings support generalised endothelial dysfunction. The arginine effects imply NO-mediated improvement of skeletal muscle perfusion suggesting improved homogeneity of microvascular distribution.

KEYWORDS Blood flow; Coronary circulation; Endothelial function; Microcirculation; Nitric oxide; Syndrome

1 Responsible for statistical assistance.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 ANGIOLOGYHome page
A.-H. Li, B.-C. Lee, K.-C. Chen, C.-S. Weng, and S.-H. Chu
Brachial Artery Flow-Mediated Vasodilation in Patients With Cardiac Syndrome X
Angiology, October 1, 2008; 59(5): 581 - 586.
[Abstract] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.