The carotid baroreflex is reset following prolonged exercise in humans

TY - JOUR

T1 - The carotid baroreflex is reset following prolonged exercise in humans

AU - Hart, E C

AU - Rasmussen, P

AU - Secher, N H

AU - George, K P

AU - Cable, N T

AU - Volianitis, Stefanos

AU - Shave, R

N1 - © 2010 The Authors. Acta Physiologica © 2010 Scandinavian Physiological Society.

PY - 2010/12/1

Y1 - 2010/12/1

N2 - Alterations in the carotid baroreflex (CBR) control of arterial pressure may explain the reduction in arterial pressure and left ventricular (LV) function after prolonged exercise. We examined the CBR control of heart rate (HR) and mean arterial pressure (MAP), in addition to changes in LV function, pre- to post-exercise.Methods: Seven males (age, mean ± SEM; 29 ± 4 years) completed 4 h of ergometer rowing at a workload of 10-15% below the lactate threshold. The CBR control of HR and MAP was assessed via the rapid neck-suction/pressure protocol. LV systolic function was measured by echocardiography, where ejection fraction (EF), the ratio of systolic blood pressure to end systolic volume (SBP/ESV) and stroke volume (SV) were estimated.Results: Following exercise MAP was reduced (12 ± 3%) and HR was elevated (35 ± 5%; P < 0.05). Furthermore, CBR control of MAP was relocated to the left on the stimulus-response curve (P < 0.05) demonstrating that the CBR operated around a lower arterial pressure. Concomitantly, LV systolic function was reduced, indicated by a decrease in EF (22 ± 2%), SBP/ESV (32 ± 14%) and SV (25 ± 5%, P < 0.05). The reduced EF and SBP/ESV were associated with the decreased MAP operating point (r2 = 0.71 and r2 = 0.47, respectively, P < 0.05).Conclusion: The CBR is reset after prolonged exercise to a lower prevailing arterial pressure. This resetting of the CBR may contribute to the reduction arterial pressure and LV function after exercise.

AB - Alterations in the carotid baroreflex (CBR) control of arterial pressure may explain the reduction in arterial pressure and left ventricular (LV) function after prolonged exercise. We examined the CBR control of heart rate (HR) and mean arterial pressure (MAP), in addition to changes in LV function, pre- to post-exercise.Methods: Seven males (age, mean ± SEM; 29 ± 4 years) completed 4 h of ergometer rowing at a workload of 10-15% below the lactate threshold. The CBR control of HR and MAP was assessed via the rapid neck-suction/pressure protocol. LV systolic function was measured by echocardiography, where ejection fraction (EF), the ratio of systolic blood pressure to end systolic volume (SBP/ESV) and stroke volume (SV) were estimated.Results: Following exercise MAP was reduced (12 ± 3%) and HR was elevated (35 ± 5%; P < 0.05). Furthermore, CBR control of MAP was relocated to the left on the stimulus-response curve (P < 0.05) demonstrating that the CBR operated around a lower arterial pressure. Concomitantly, LV systolic function was reduced, indicated by a decrease in EF (22 ± 2%), SBP/ESV (32 ± 14%) and SV (25 ± 5%, P < 0.05). The reduced EF and SBP/ESV were associated with the decreased MAP operating point (r2 = 0.71 and r2 = 0.47, respectively, P < 0.05).Conclusion: The CBR is reset after prolonged exercise to a lower prevailing arterial pressure. This resetting of the CBR may contribute to the reduction arterial pressure and LV function after exercise.

U2 - 10.1111/j.1748-1716.2010.02160.x

DO - 10.1111/j.1748-1716.2010.02160.x

M3 - Journal article

SN - 1748-1708

VL - 200

SP - 291

EP - 299

JO - Acta Physiologica (Print)

JF - Acta Physiologica (Print)

IS - 4

ER -