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Peripheral vasodilatation determines cardiac output in exercising humans: insight from atrial pacing
Author(s) -
Bada A. A.,
Svendsen J. H.,
Secher N. H.,
Saltin B.,
Mortensen S. P.
Publication year - 2012
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2011.225334
Subject(s) - cardiac output , medicine , heart rate , cardiology , cardiac index , vasodilation , central venous pressure , hemodynamics , blood pressure , stroke volume , contractility , venous return curve , peripheral , perfusion , mean arterial pressure , anesthesia
Key points • During exercise, cardiac output is regulated to match oxygen delivery to the metabolic demand. • This study evaluated the role of heart rate and peripheral vasodilation in the regulation of cardiac output during exercise. • We increased heart rate by atrial pacing in 10 healthy male individuals during three different conditions: at rest, during exercise and during femoral arterial ATP infusion at rest. • Increasing the heart rate by atrial pacing by up to 54 beats min −1 did not increase cardiac output in any of the three given conditions as there was a proportional decrease in stroke volume. • These results indicate that cardiac output is regulated by changes in peripheral vasodilatation, whereas an increase in heart rate is less important.