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: 293/3/H1929    most recent 00564.2007v1 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 (5) Citing Articles via Google Scholar Google Scholar Articles by Iellamo, F. Articles by O'Leary, D. S. Search for Related Content PubMed PubMed Citation Articles by Iellamo, F. Articles by O'Leary, D. S.

Spontaneous baroreflex control of heart rate during exercise and muscle metaboreflex activation in heart failure

¹Dipartimento Medicina Interna, Universita di Roma Tor Vergata; ²IRCCS San Raffaele Pisana, Rome, Italy; Departments of ³Physiology and ⁴Surgery, Wayne State University School of Medicine, Detroit, Michigan; ⁵Laboratory for Applied Human Physiology, Faculty of Human Development, Kobe University, Kobe, Japan; ⁶Laboratory for Human performance Research, Osaka International University, Osaka, Japan

Submitted 15 May 2007 ; accepted in final form 25 June 2007

In heart failure (HF), there is a reduced baroreflex sensitivity at rest, and during dynamic exercise there is enhanced muscle metaboreflex activation (MRA). However, how the arterial baroreflex modulates HR during exercise is unknown. We tested the hypothesis that spontaneous baroreflex sensitivity (SBRS) is attenuated during exercise in HF and that MRA further depresses SBRS. In seven conscious dogs we measured heart rate (HR), cardiac output, and left ventricular systolic pressure at rest and during mild and moderate dynamic exercise, before and during MRA (via imposed reductions of hindlimb blood flow), and before and after induction of HF (by rapid ventricular pacing). SBRS was assessed by the sequences method. In control, SBRS was reduced from rest with a progressive resetting of the baroreflex stimulus-response relationship in proportion to exercise intensity and magnitude of MRA. In HF, SBRS was significantly depressed in all settings; however, the changes with exercise and MRA occurred with a pattern similar to the control state. As in control, the baroreflex stimulus-response relationship showed an intensity- and muscle metaboreflex (MMR)-dependent rightward and upward shift. The results of this study indicate that HF induces an impairment in baroreflex control of HR at rest and during exercise, although the effects of exercise and MRA on SBRS occur with a similar pattern as in control, indicating the persistence of some vagal activity.

nervous system; autonomic; blood pressure; skeletal muscle afferents

This article has been cited by other articles:

				G. Caminiti, M. Volterrani, F. Iellamo, G. Marazzi, R. Massaro, M. Miceli, C. Mammi, M. Piepoli, M. Fini, and G. M.C. Rosano Effect of long-acting testosterone treatment on functional exercise capacity, skeletal muscle performance, insulin resistance, and baroreflex sensitivity in elderly patients with chronic heart failure a double-blind, placebo-controlled, randomized study. J. Am. Coll. Cardiol., September 1, 2009; 54(10): 919 - 927. [Abstract] [Full Text] [PDF]

				J. A. Sala-Mercado, M. Ichinose, R. L. Hammond, M. Coutsos, T. Ichinose, M. Pallante, F. Iellamo, and D. S. O'Leary Spontaneous baroreflex control of heart rate versus cardiac output: altered coupling in heart failure Am J Physiol Heart Circ Physiol, March 1, 2008; 294(3): H1304 - H1309. [Abstract] [Full Text] [PDF]

				M. Ichinose, J. A. Sala-Mercado, D. S. O'Leary, R. L. Hammond, M. Coutsos, T. Ichinose, M. Pallante, and F. Iellamo Spontaneous baroreflex control of cardiac output during dynamic exercise, muscle metaboreflex activation, and heart failure Am J Physiol Heart Circ Physiol, March 1, 2008; 294(3): H1310 - H1316. [Abstract] [Full Text] [PDF]