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Model simulations of cardiovascular changes at the onset of moderate exercise in humans
Author(s) -
Elstad Maja,
Toska Karin,
Walløe Lars
Publication year - 2002
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.2002.019422
Subject(s) - baroreflex , medicine , cardiology , heart rate , blood pressure , baroreceptor , vasodilation , reflex , stroke volume , peripheral , anesthesia
We have tested whether the cardiovascular changes at the onset of exercise could be simulated only by an increase in the baroreflex set point and locally induced vasodilatation in the exercising muscles. The mathematical model consists of a heart, a linear elastic arterial reservoir and two parallel resistive vascular beds. The arterial baroreflex loop is modelled by three separate time domain processing objects, each with its own gain, time constant and delay. These are intended to simulate the action of a sympathetic signal to the peripheral vascular bed, a parasympathetic signal to the heart and a sympathetic signal to the heart. We used this model with previously published experimental data to estimate the unknown parameters in the reflex control loop. In all 10 subjects and in the global averaged response, the short‐term cardiovascular responses were adequately simulated by using individual sets of parameters in the model. An increase in the baroreflex set point and locally induced vasodilatation in the exercising muscles can explain almost all of the cardiovascular changes in the recorded variables (mean arterial pressure, RR interval and stroke volume) at the onset of exercise.