Association Between Aerobic Capacity and Carotid-Cardiac Baroreflex Responsiveness in Women

1998 ◽  
Vol 23 (5) ◽  
pp. 444-460 ◽  
Author(s):  
Tania L. Culham ◽  
Gabrielle K. Savard
Keyword(s):  
Blood Pressure ◽  
Exercise Training ◽  
Aerobic Capacity ◽  
Group Differences ◽  
Arterial Baroreflex ◽  
Key Words Blood Pressure ◽  
Endurance Exercise Training ◽  
Carotid Baroreflex ◽  
Neck Pressure ◽  
Key Words Blood

The purpose of this study was to determine whether the positive correlation between carotid-cardiac baroreflex responsiveness and aerobic capacity [Formula: see text] that has been reported in men also occurs in women. Carotid-cardiac baroreflex responsiveness was tested in 40 healthy, normotensive women (age 18-35), using the variable neck pressure technique. Participants were subdivided into endurance-trained (ET; n = 11) and untrained (UT; n = 9) groups. No significant between-group difference was found in the range or gain of the carotid-cardiac baroreflex response despite a lower resting HR in the ET group. When participants were subdivided into high (HI: n = 13) and low (LO; n = 17) responders based on reflex RRI responses to CTP changes, no significant between-group differences were found in resting HR or [Formula: see text] levels. It was concluded that aerobic capacity [Formula: see text] is not a good predictor of cardiac-carotid baroreflex responsiveness in healthy women. Key words: blood pressure, endurance exercise training, aerobic capacity, carotid transmural pressure, arterial baroreflex

scholarly journals Carotid baroreflex control of arterial blood pressure at rest and during dynamic exercise in aging humans

2010 ◽  
Vol 299 (5) ◽  
pp. R1241-R1247 ◽  
Author(s):  
James P. Fisher ◽  
Areum Kim ◽  
Colin N. Young ◽  
Paul J. Fadel
Keyword(s):  
Blood Pressure ◽  
Response Curve ◽  
Dynamic Exercise ◽  
Baroreflex Control ◽  
Stimulus Response ◽  
Arterial Blood ◽  
Carotid Baroreflex ◽  
Older Subjects ◽  
Maximal Gain ◽  
Neck Pressure

The arterial baroreflex is fundamental for evoking and maintaining appropriate cardiovascular adjustments to exercise. We sought to investigate how aging influences carotid baroreflex regulation of blood pressure (BP) during dynamic exercise. BP and heart rate (HR) were continuously recorded at rest and during leg cycling performed at 50% HR reserve in 15 young (22 ± 1 yr) and 11 older (61 ± 2 yr) healthy subjects. Five-second pulses of neck pressure and neck suction from +40 to −80 Torr were applied to determine the full carotid baroreflex stimulus response curve and examine baroreflex resetting during exercise. Although the maximal gain of the modeled stimulus response curve was similar in both groups at rest and during exercise, in older subjects the operating point (OP) was located further away from the centering point (CP) and toward the reflex threshold, both at rest (OP minus CP; −10 ± 3 older vs. 0 ± 2 young mmHg, P < 0.05) and during exercise (OP minus CP; −10 ± 2 older vs. 1 ± 3 young mmHg, P < 0.05). In agreement, older subjects demonstrated a reduced BP response to neck pressure (simulated carotid hypotension) and a greater BP response to neck suction (simulated carotid hypertension). In addition, the magnitude of the upward and rightward resetting of the carotid baroreflex-BP stimulus response curve with exercise was ∼40% greater in older individuals. These data indicate that despite a maintained maximal gain, the ability of the carotid baroreflex to defend against a hypotensive challenge is reduced, whereas responses to hypertensive stimuli are greater with advanced age, both at rest and during exercise.

scholarly journals Upward resetting of the vascular sympathetic baroreflex in middle-aged male runners

2019 ◽  
Vol 317 (1) ◽  
pp. H181-H189 ◽  
Author(s):  
Denis J. Wakeham ◽  
Rachel N. Lord ◽  
Jack S. Talbot ◽  
Freya M. Lodge ◽  
Bryony A. Curry ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Exercise Training ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Endurance Exercise ◽  
Left Ventricular ◽  
Middle Aged ◽  
Endurance Exercise Training ◽  
Pressure Stability ◽  
Age Category

This study focused on the influence of habitual endurance exercise training (i.e., committed runner or nonrunner) on the regulation of muscle sympathetic nerve activity (MSNA) and arterial pressure in middle-aged (50 to 63 yr, n = 23) and younger (19 to 30 yr; n = 23) normotensive men. Hemodynamic and neurophysiological assessments were performed at rest. Indices of vascular sympathetic baroreflex function were determined from the relationship between spontaneous changes in diastolic blood pressure (DBP) and MSNA. Large vessel arterial stiffness and left ventricular stroke volume also were measured. Paired comparisons were performed within each age category. Mean arterial pressure and basal MSNA bursts/min were not different between age-matched runners and nonrunners. However, MSNA bursts/100 heartbeats, an index of baroreflex regulation of MSNA (vascular sympathetic baroreflex operating point), was higher for middle-aged runners ( P = 0.006), whereas this was not different between young runners and nonrunners. The slope of the DBP-MSNA relationship (vascular sympathetic baroreflex gain) was not different between groups in either age category. Aortic pulse wave velocity was lower for runners of both age categories ( P < 0.03), although carotid β-stiffness was lower only for middle-aged runners ( P = 0.04). For runners of both age categories, stroke volume was larger, whereas heart rate was lower (both P < 0.01). In conclusion, we suggest that neural remodeling and upward setting of the vascular sympathetic baroreflex compensates for cardiovascular adaptations after many years committed to endurance exercise training, presumably to maintain arterial blood pressure stability. NEW & NOTEWORTHY Exercise training reduces muscle sympathetic burst activity in disease; this is often extrapolated to infer a similar effect in health. We demonstrate that burst frequency of middle-aged and younger men committed to endurance training is not different compared with age-matched casual exercisers. Notably, well-trained, middle-aged runners display similar arterial pressure but higher sympathetic burst occurrence than untrained peers. We suggest that homeostatic plasticity and upward setting of the vascular sympathetic baroreflex maintains arterial pressure stability following years of training.

Correction: Endurance Exercise Training reduces Blood Pressure according to the Wilder’s Principle

2021 ◽  
Author(s):  
Ricardo Mora-Rodriguez ◽  
Juan Fernando Ortega ◽  
Felix Morales-Palomo ◽  
Miguel Ramirez-Jimenez ◽  
Alfonso Moreno-Cabañas ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Exercise Training ◽  
Endurance Exercise ◽  
Endurance Exercise Training

Modulation of arterial baroreflex control of heart rate by skin cooling and heating in humans

2000 ◽  
Vol 88 (2) ◽  
pp. 393-400 ◽  
Author(s):  
Fumio Yamazaki ◽  
Ryoko Sone
Keyword(s):  
Heart Rate ◽  
Thermal Stress ◽  
Arterial Pressure ◽  
Baroreflex Sensitivity ◽  
Whole Body ◽  
Arterial Baroreflex ◽  
Carotid Baroreflex ◽  
Skin Cooling ◽  
Neck Pressure ◽  
Arterial Baroreflex Sensitivity

The purpose of this study was to examine the effects of skin cooling and heating on the heart rate (HR) control by the arterial baroreflex in humans. The subjects were 15 healthy men who underwent whole body thermal stress (esophageal temperatures, ∼36.8 and ∼37.0°C; mean skin temperatures, ∼26.4 and ∼37.7°C, in skin cooling and heating, respectively) produced by a cool or hot water-perfused suit during supine rest. The overall arterial baroreflex sensitivity in the HR control was calculated from spontaneous changes in beat-to-beat arterial pressure and HR during normothermic control and thermal stress periods. The carotid baroreflex sensitivity was evaluated from the maximum slope of the HR response to changes in carotid distending pressure, calculated as mean arterial pressure minus neck pressure. The overall arterial baroreflex sensitivity at existing arterial pressure increased during cooling (−1.32 ± 0.25 vs. −2.13 ± 0.20 beats ⋅ min− 1 ⋅ mmHg− 1 in the control and cooling periods, respectively, P < 0.05), whereas it did not change significantly during heating (−1.39 ± 0.23 vs. −1.40 ± 0.15 beats ⋅ min− 1 ⋅ mmHg− 1in the control and heating periods, respectively). Neither the cool nor heat loadings altered the carotid baroreflex sensitivity in the HR control. These results suggest that the sensitivity of HR control by the extracarotid (presumably aortic) baroreflex was augumented by whole body skin cooling, whereas the sensitivities of HR control by arterial baroreflex remain unchanged during mild whole body heating in humans.

Carotid baroreflex function during and following voluntary apnea in humans

2003 ◽  
Vol 285 (6) ◽  
pp. H2411-H2419 ◽  
Author(s):  
N. Muenter Swift ◽  
M. J. Cutler ◽  
P. J. Fadel ◽  
W. L. Wasmund ◽  
S. Ogoh ◽  
...  
Keyword(s):  
Arterial Pressure ◽  
Sympathetic Nerve Activity ◽  
Muscle Sympathetic Nerve Activity ◽  
Cardiac Response ◽  
Inhibitory Input ◽  
Arterial Baroreflex ◽  
Baroreflex Control ◽  
Carotid Baroreflex ◽  
Neck Pressure ◽  
Voluntary Apnea

Muscle sympathetic nerve activity (MSNA) and arterial pressure increase concomitantly during apnea, suggesting a possible overriding of arterial baroreflex inhibitory input to sympathoregulatory centers by apnea-induced excitatory mechanisms. Apnea termination is accompanied by strong sympathoinhibition while arterial pressure remains elevated. Therefore, we hypothesized that the sensitivity of carotid baroreflex control of MSNA would decrease during apnea and return upon apnea termination. MSNA and heart rate responses to –60-Torr neck suction (NS) were evaluated during baseline and throughout apnea. Responses to +30-Torr neck pressure (NP) were evaluated during baseline and throughout 1 min postapnea. Apnea did not affect the sympathoinhibitory or bradycardic response to NS ( P > 0.05); however, whereas the cardiac response to NP was maintained postapnea, the sympathoexcitatory response was reduced for 50 s ( P < 0.05). These data demonstrate that the sensitivity of carotid baroreflex control of MSNA is not attenuated during apnea. We propose a transient rightward and upward resetting of the carotid baroreflex-MSNA function curve during apnea and that return of the function curve to, or more likely beyond, baseline (i.e., a downward and leftward shift) upon apnea termination may importantly contribute to the reduced sympathoexcitatory response to NP.

Carotid baroreflex control of leg vascular conductance at rest and during exercise

2003 ◽  
Vol 94 (2) ◽  
pp. 542-548 ◽  
Author(s):  
David M. Keller ◽  
Wendy L. Wasmund ◽  
D. Walter Wray ◽  
Shigehiko Ogoh ◽  
Paul J. Fadel ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Vascular Tone ◽  
Knee Extension ◽  
Vascular Conductance ◽  
Baroreflex Control ◽  
Carotid Baroreflex ◽  
Neck Pressure ◽  
Induced Changes ◽  
Knee Extension Exercise ◽  
Rest And Exercise

We sought to test the hypothesis that the carotid baroreflex (CBR) alters mean leg blood flow (LBF) and leg vascular conductance (LVC) at rest and during exercise. In seven men and one woman, 25 ± 2 (SE) yr of age, CBR control of LBF and LVC was determined at rest and during steady-state one-legged knee extension exercise at ∼65% peak O2 uptake. The application of 5-s pulses of +40 Torr neck pressure and −60 Torr neck suction significantly altered mean arterial pressure (MAP) and LVC both at rest and during exercise. CBR-mediated changes in MAP were similar between rest and exercise ( P > 0.05). However, CBR-mediated decreases in LVC (%change) to neck pressure were attenuated in the exercising leg (16.4 ± 1.6%) compared with rest (33 ± 2.1%) and the nonexercising leg (23.7 ± 1.9%) ( P < 0.01). These data suggest CBR control of blood pressure is partially mediated by changes in leg vascular tone both at rest and during exercise. Furthermore, despite alterations in CBR-induced changes in LVC during exercise, CBR control of blood pressure was well maintained.

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