HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 291/2/H921    most recent 00986.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (9) Citing Articles via Google Scholar Google Scholar Articles by Guazzi, M. Articles by Guazzi, M. D. Search for Related Content PubMed PubMed Citation Articles by Guazzi, M. Articles by Guazzi, M. D.

Endothelial dysfunction and exercise performance in lone atrial fibrillation or associated with hypertension or diabetes: different results with cardioversion

¹Cardiopulmonary Unit, Cardiology Division, University of Milan, San Paolo Hospital; and ²Institute of Cardiology, University of Milan, Milan, Italy

Submitted 15 September 2005 ; accepted in final form 31 January 2006

Endothelial dysfunction and underperfusion of exercising muscle contribute to exercise intolerance, hyperventilation, and breathlessness in atrial fibrillation (AF). Cardioversion (CV) improves endothelial function and exercise performance. We examined whether CV is equally beneficial in diabetes and hypertension, diseases that cause endothelial dysfunction and are often associated with AF. Cardiopulmonary exercise and pulmonary and endothelial (brachial artery flow-mediated dilation) function were tested before and after CV in patients with AF alone (n = 18, group 1) or AF with hypertension (n = 19, group 2) or diabetes (n = 19, group 3). Compared with group 1, peak exercise workload, O₂ consumption (O₂), O₂ pulse, aerobic efficiency (O₂/WR), and ratio of brachial diameter changes to flow changes (D/F) were reduced in group 2 and, to a greater extent, in group 3; exercise ventilation efficiency (E/CO₂ slope) and dead space-to-tidal volume ratio (VD/VT) were similar among groups. CV had less effect on peak workload (+7% vs. +18%), peak O₂ (+12% vs. +17%), O₂ pulse (+33% vs. +50%), O₂/WR (+7% vs. +12%), E/CO₂ slope (–6% vs. –12%), D/F (+7% vs. +10%), and breathlessness (Borg scale) in group 2 than in group 1 and was ineffective in group 3. The antioxidant vitamin C, tested in eight additional patients in each cohort, improved flow-mediated dilation in groups 1 and 2 before, but not after, CV and was ineffective in group 3, suggesting that the oxidative injury is least in lone AF, greater in hypertension with AF, and greater still in diabetes with AF. Comorbidities that impair endothelial activity worsen endothelial dysfunction and exercise intolerance in AF. The advantages of CV appear to be inversely related to the extent of the underlying oxidative injury.

arrhythmias; endothelium; exercise

This article has been cited by other articles:

				M Guazzi and R Arena Endothelial dysfunction and pathophysiological correlates in atrial fibrillation Heart, January 15, 2009; 95(2): 102 - 106. [Abstract] [Full Text] [PDF]

				M. Guazzi, M. Samaja, R. Arena, M. Vicenzi, and M. D. Guazzi Long-Term Use of Sildenafil in the Therapeutic Management of Heart Failure J. Am. Coll. Cardiol., November 27, 2007; 50(22): 2136 - 2144. [Abstract] [Full Text] [PDF]

				M. Guazzi, M. Berti, S. Belletti, G. Reina, and M. D. Guazzi Exercise metaboreflex activation and endothelial function impairment in atrial fibrillation Am J Physiol Heart Circ Physiol, November 1, 2006; 291(5): H2396 - H2402. [Abstract] [Full Text] [PDF]