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Joyner MJ, Casey DP. Regulation of increased blood flow (hyperemia) to muscles during exercise: a hierarchy of competing physiological needs. Physiol Rev 2015; 95:549-601. [PMID: 25834232 DOI: 10.1152/physrev.00035.2013] [Citation(s) in RCA: 422] [Impact Index Per Article: 46.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This review focuses on how blood flow to contracting skeletal muscles is regulated during exercise in humans. The idea is that blood flow to the contracting muscles links oxygen in the atmosphere with the contracting muscles where it is consumed. In this context, we take a top down approach and review the basics of oxygen consumption at rest and during exercise in humans, how these values change with training, and the systemic hemodynamic adaptations that support them. We highlight the very high muscle blood flow responses to exercise discovered in the 1980s. We also discuss the vasodilating factors in the contracting muscles responsible for these very high flows. Finally, the competition between demand for blood flow by contracting muscles and maximum systemic cardiac output is discussed as a potential challenge to blood pressure regulation during heavy large muscle mass or whole body exercise in humans. At this time, no one dominant dilator mechanism accounts for exercise hyperemia. Additionally, complex interactions between the sympathetic nervous system and the microcirculation facilitate high levels of systemic oxygen extraction and permit just enough sympathetic control of blood flow to contracting muscles to regulate blood pressure during large muscle mass exercise in humans.
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Affiliation(s)
- Michael J Joyner
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota; and Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, Iowa
| | - Darren P Casey
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota; and Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, Iowa
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Steding-Ehrenborg K, Jablonowski R, Arvidsson PM, Carlsson M, Saltin B, Arheden H. Moderate intensity supine exercise causes decreased cardiac volumes and increased outer volume variations: a cardiovascular magnetic resonance study. J Cardiovasc Magn Reson 2013; 15:96. [PMID: 24156367 PMCID: PMC4015552 DOI: 10.1186/1532-429x-15-96] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 10/01/2013] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The effects on left and right ventricular (LV, RV) volumes during physical exercise remains controversial. Furthermore, no previous study has investigated the effects of exercise on longitudinal contribution to stroke volume (SV) and the outer volume variation of the heart. The aim of this study was to determine if LV, RV and total heart volumes (THV) as well as cardiac pumping mechanisms change during physical exercise compared to rest using cardiovascular magnetic resonance (CMR). METHODS 26 healthy volunteers (6 women) underwent CMR at rest and exercise. Exercise was performed using a custom built ergometer for one-legged exercise in the supine position during breath hold imaging. Cardiac volumes and atrio-ventricular plane displacement were determined. Heart rate (HR) was obtained from ECG. RESULTS HR increased during exercise from 60±2 to 94±2 bpm, (p<0.001). LVEDV remained unchanged (p=0.81) and LVESV decreased with -9±18% (p<0.05) causing LVSV to increase with 8±3% (p<0.05). RVEDV and RVESV decreased by -7±10% and -24±14% respectively, (p<0.001) and RVSV increased 5±17% during exercise although not statistically significant (p=0.18). Longitudinal contribution to RVSV decreased during exercise by -6±15% (p<0.05) but was unchanged for LVSV (p=0.74). THV decreased during exercise by -4±1%, (p<0.01) and total heart volume variation (THVV) increased during exercise from 5.9±0.5% to 9.7±0.6% (p<0.001). CONCLUSIONS Cardiac volumes and function are significantly altered during supine physical exercise. THV becomes significantly smaller due to decreases in RVEDV whilst LVEDV remains unchanged. THVV and consequently radial pumping increases during exercise which may improve diastolic suction during the rapid filling phase.
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Affiliation(s)
- Katarina Steding-Ehrenborg
- Copenhagen Muscle Research Centre, Copenhagen, Denmark
- Danish Research Centre for Magnetic Resonance, Hvidovre Hospital, Copenhagen, Denmark
| | - Robert Jablonowski
- Department of Clinical Physiology, Lund University, Lund University Hospital Lund, Lund, Sweden
| | - Per M Arvidsson
- Department of Clinical Physiology, Lund University, Lund University Hospital Lund, Lund, Sweden
| | - Marcus Carlsson
- Department of Clinical Physiology, Lund University, Lund University Hospital Lund, Lund, Sweden
| | - Bengt Saltin
- Copenhagen Muscle Research Centre, Copenhagen, Denmark
| | - Håkan Arheden
- Department of Clinical Physiology, Lund University, Lund University Hospital Lund, Lund, Sweden
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Masuki S, Eisenach JH, Schrage WG, Johnson CP, Dietz NM, Wilkins BW, Sandroni P, Low PA, Joyner MJ. Reduced stroke volume during exercise in postural tachycardia syndrome. J Appl Physiol (1985) 2007; 103:1128-35. [PMID: 17626834 DOI: 10.1152/japplphysiol.00175.2007] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Postural tachycardia syndrome (POTS) is characterized by excessive tachycardia without hypotension during orthostasis. Most POTS patients also report exercise intolerance. To assess cardiovascular regulation during exercise in POTS, patients (n = 13) and healthy controls (n = 10) performed graded cycle exercise at 25, 50, and 75 W in both supine and upright positions while arterial pressure (arterial catheter), heart rate (HR; measured by ECG), and cardiac output (open-circuit acetylene breathing) were measured. In both positions, mean arterial pressure, cardiac output, and total peripheral resistance at rest and during exercise were similar in patients and controls (P > 0.05). However, supine stroke volume (SV) tended to be lower in the patients than controls at rest (99 +/- 5 vs. 110 +/- 9 ml) and during 75-W exercise (97 +/- 5 vs. 111 +/- 7 ml) (P = 0.07), and HR was higher in the patients than controls at rest (76 +/- 3 vs. 62 +/- 4 beats/min) and during 75-W exercise (127 +/- 3 vs. 114 +/- 5 beats/min) (both P < 0.01). Upright SV was significantly lower in the patients than controls at rest (57 +/- 3 vs. 81 +/- 6 ml) and during 75-W exercise (70 +/- 4 vs. 94 +/- 6 ml) (both P < 0.01), and HR was much higher in the patients than controls at rest (103 +/- 3 vs. 81 +/- 4 beats/min) and during 75-W exercise (164 +/- 3 vs. 131 +/- 7 beats/min) (both P < 0.001). The change (upright - supine) in SV was inversely correlated with the change in HR for all participants at rest (R(2) = 0.32), at 25 W (R(2) = 0.49), 50 W (R(2) = 0.60), and 75 W (R(2) = 0.32) (P < 0.01). These results suggest that greater elevation in HR in POTS patients during exercise, especially while upright, was secondary to reduced SV and associated with exercise intolerance.
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Affiliation(s)
- Shizue Masuki
- Department of Anesthesiology, Mayo Clinic Foundation, Rochester, MN 55905, USA
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Abstract
This paper briefly reviews the historical evolution of ideas about how baroreflexes operate and continue to regulate arterial blood pressure during exercise. Observations from studies conducted in conscious humans and animals are emphasized and three main questions are asked. First, do baroreflexes contribute to arterial blood pressure regulation during exercise? Second, if baroreflexes contribute to blood pressure regulation during exercise, how do they do it? Third, are there any pathophysiological conditions in which manipulation of baroreflexes or baroreflex 'dysfunction' might alter exercise responses? In this context, ideas related to baroreflex resetting during exercise are emphasized, and the potential improvement in exercise tolerance in cardiovascular disease that might be achieved by electrical stimulation of the carotid sinus nerve is highlighted. Additionally, the key contributions of John Shepherd and the late David Donald (along with their colleagues) on related issues are noted.
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Affiliation(s)
- Michael J Joyner
- Department of Anaesthesiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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Heslop DJ, Bandler R, Keay KA. Haemorrhage-evoked decompensation and recompensation mediated by distinct projections from rostral and caudal midline medulla in the rat. Eur J Neurosci 2004; 20:2096-110. [PMID: 15450089 DOI: 10.1111/j.1460-9568.2004.03660.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The haemodynamic response to blood loss consists of three phases: (i) an initial compensatory phase during which resting arterial pressure is maintained; (ii) a decompensatory phase characterized by a sudden, life-threatening hypotension and bradycardia; and (iii) if blood loss ceases, a recompensatory phase during which arterial pressure returns to normal. Previous research indicates that topographically distinct, rostral and caudal parts of the caudal midline medulla (CMM) contain neurons that differentially regulate the timing and magnitude of each of the three phases. Specifically, decompensation depends critically on the integrity of the rostral CMM; whereas compensation and recompensation depend upon the integrity of the caudal CMM. This study aimed to determine, using retrograde and anterograde tracing techniques, if the rostral and caudal CMM gave rise to different sets of projections to the major cardiovascular region of the ventrolateral medulla (VLM) and spinal cord. It was found that rostral and caudal CMM each have projections of varying density to the region containing bulbospinal (presympathetic) motor neurons in the rostral VLM and preganglionic sympathetic motor neurons in the intermediolateral cell column of the spinal cord. Via these projections vasomotor tone and hence arterial pressure can be regulated. More strikingly: (i) consistent with a role in mediating bradycardia during decompensation, the rostral CMM projects uniquely to VLM regions containing vagal cardiac motor neurons; and (ii) consistent with its role in mediating recompensation, the caudal CMM projects uniquely onto tyrosine hydroxylase-containing, caudal VLM (A1) neurons whose activity mediates vasopressin release, on which recompensation depends.
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Affiliation(s)
- David J Heslop
- Department of Anatomy & Histology, The University of Sydney, NSW, Australia 2006
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Kerman IA, Emanuel BA, Yates BJ. Vestibular stimulation leads to distinct hemodynamic patterning. Am J Physiol Regul Integr Comp Physiol 2000; 279:R118-25. [PMID: 10896872 DOI: 10.1152/ajpregu.2000.279.1.r118] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies demonstrated that responses of a particular sympathetic nerve to vestibular stimulation depend on the type of tissue the nerve innervates as well as its anatomic location. In the present study, we sought to determine whether such precise patterning of vestibulosympathetic reflexes could lead to specific hemodynamic alterations in response to vestibular afferent activation. We simultaneously measured changes in systemic blood pressure and blood flow (with the use of Doppler flowmetry) to the hindlimb (femoral artery), forelimb (brachial artery), and kidney (renal artery) in chloralose-urethane-anesthetized, baroreceptor-denervated cats. Electrical vestibular stimulation led to depressor responses, 8 +/- 2 mmHg (mean +/- SE) in magnitude, that were accompanied by decreases in femoral vasoconstriction (23 +/- 4% decrease in vascular resistance or 36 +/- 7% increase in vascular conductance) and increases in brachial vascular tone (resistance increase of 10 +/- 6% and conductance decrease of 11 +/- 4%). Relatively small changes (<5%) in renal vascular tone were observed. In contrast, electrical stimulation of muscle and cutaneous afferents produced pressor responses (20 +/- 6 mmHg) that were accompanied by vasoconstriction in all three beds. These data suggest that vestibular inputs lead to a complex pattern of cardiovascular changes that is distinct from that which occurs in response to activation of other types of somatic afferents.
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Affiliation(s)
- I A Kerman
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
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Legramante JM, Raimondi G, Adreani CM, Sacco S, Iellamo F, Peruzzi G, Kaufman MP. Group III muscle afferents evoke reflex depressor responses to repetitive muscle contractions in rabbits. Am J Physiol Heart Circ Physiol 2000; 278:H871-7. [PMID: 10710356 DOI: 10.1152/ajpheart.2000.278.3.h871] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Repetitive-twitch contraction of the hindlimb muscles in anesthetized rabbits consistently evokes a reflex depressor response, whereas this type of contraction in anesthetized cats evokes a reflex pressor response in about one-half of the preparations tested. Rapidly conducting group III fibers appear to comprise the afferent arm of the reflex arc, evoking the depressor response to twitch contraction in rabbits because electrical stimulation of their axons reflexly decreases arterial pressure. In contrast, electrical stimulation of the axons of slowly conducting group III and group IV afferents reflexly increases arterial pressure in rabbits. In the present study, we examined the discharge properties of group III and IV muscle afferents and found that the former (i.e., 13 of 20), but not the latter (i.e., 0 of 10), were stimulated by 5 min of repetitive-twitch contraction (1 Hz) of the rabbit triceps surae muscles. Moreover, most of the group III afferents responding to contraction appeared to be mechanically sensitive, discharging in synchrony with the muscle twitch. On average, rapidly conducting group III afferents responded for the 5-min duration of 1-Hz repetitive-twitch contraction, whereas slowly conducting group III afferents responded only for the first 2 min of contraction. We conclude that rapidly conducting group III afferents, which are mechanically sensitive, are primarily responsible for evoking the reflex depressor response to repetitive-twitch contractions in anesthetized rabbits.
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Affiliation(s)
- J M Legramante
- Dipartimento di Medicina Interna, Cattedra di Fisiopatologia Medica, Universita' di Roma "Tor Vergata," 00173 Rome, Italy.
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Li Z, Morris KF, Baekey DM, Shannon R, Lindsey BG. Responses of simultaneously recorded respiratory-related medullary neurons to stimulation of multiple sensory modalities. J Neurophysiol 1999; 82:176-87. [PMID: 10400946 DOI: 10.1152/jn.1999.82.1.176] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study addresses the hypothesis that multiple afferent systems share elements of a distributed brain stem network that modulates the respiratory motor pattern. Data were collected from 18 decerebrate, bilaterally vagotomized, paralyzed, artificially ventilated cats. Up to 28 neurons distributed in the rostral and caudal ventral respiratory group, nucleus tractus solitarius, and raphe obscurus were recorded simultaneously with microelectrode arrays. Phases of the respiratory cycle and inspiratory drive were assessed from integrated efferent phrenic nerve activity. Carotid chemoreceptors were stimulated by injection of CO2-saturated saline solution via the external carotid artery. Baroreceptors were stimulated by increased blood pressure secondary to inflation of an embolectomy catheter in the descending aorta. Cutaneous nociceptors were stimulated by pinching a footpad. Four hundred seventy-four neurons were tested for respiratory modulated firing rates and responses; 403 neurons were tested with stimulation of all 3 modalities. Chemoreceptor stimulation and pinch, perturbations that tend to increase respiratory drive, caused similar responses in 52 neurons; 28 responded oppositely. Chemoreceptor and baroreceptor stimulation resulted in similar primary responses in 45 neurons; 48 responded oppositely. Similar responses to baroreceptor stimulation and pinch were recorded for 38 neurons; opposite effects were measured in 26 neurons. Among simultaneously recorded neurons, distinct combinations of firing rate changes were evoked in response to stimulation of the different modalities. The results show a functional convergence of information from carotid chemoreceptors, baroreceptors, and cutaneous nociceptors on respiratory-modulated neurons distributed in the medulla. The data are consistent with the hypothesis that brain stem neurons have overlapping memberships in multifunctional groups that influence the respiratory motor pattern.
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Affiliation(s)
- Z Li
- Department of Physiology and Biophysics, University of South Florida Health Sciences Center, Tampa, Florida 33612-4799, USA
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Jensen-Urstad M, Bouvier F, Nejat M, Saltin B, Brodin LA. Left ventricular function in endurance runners during exercise. ACTA PHYSIOLOGICA SCANDINAVICA 1998; 164:167-72. [PMID: 9805103 DOI: 10.1046/j.1365-201x.1998.00410.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Left ventricular function in elite runners and controls was compared by means of nuclear angiocardiography. Fifteen middle- or long-distance runners and a control group of 10 sedentary to moderately physically active subjects were studied at rest and during semi-sitting incremental exercise. Ejection fraction was higher in the runners than the controls both at rest and during exercise. At the transition from rest to exercise left ventricular end-diastolic volume initially increased similarly in runners and controls by an average of 14 and 12%, respectively, with an increase in stroke volume by approximately 25 and 23%. The parallel increase in stroke volume and left ventricular end-diastolic volume could at least partly be because of the Frank-Starling mechanism. With increasing workloads, left ventricular end-diastolic volume and ejection fraction remained fairly constant, resulting in an unchanged stroke volume from the lowest to the highest exercise intensity. This was in the runners accomplished by a 41% increase in peak filling rate and a 38% increase in peak emptying rate with similar changes observed in the controls. This has to be due to increased myocardial contractility paralleling the systolic shortening with increasing heart rate. We conclude that endurance-trained athletes have a better systolic function expressed as higher ejection fraction both at rest and during exercise than untrained subjects reflecting an enhanced myocardial contractility contributing to the maintenance of a large stroke volume during exercise. The regulatory mechanisms however, appear to be similar for athletes and healthy controls.
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Affiliation(s)
- M Jensen-Urstad
- Department of Cardiology, Karolinska Hospital, Stockholm, Sweden
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Henderson LA, Keay KA, Bandler R. Hypotension following acute hypovolaemia depends on the caudal midline medulla. Neuroreport 1998; 9:1839-44. [PMID: 9665612 DOI: 10.1097/00001756-199806010-00032] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Acute hypovolaemia evokes abrupt, life-threatening hypotension and bradycardia. Hypotension can be evoked also by excitation of the caudal midline medulla (CMM). This study investigated the possible contribution of the CMM depressor area to hypotension evoked by acute hypovolaemia. Inactivation of the CMM, with either lignocaine or cobalt chloride did not alter resting arterial pressure. However lignocaine injections blocked the fall in arterial pressure, and cobalt chloride injections delayed the onset and significantly attenuated the size of hypovolaemic-evoked hypotension. These findings suggest that the CMM is a key region triggering hypotension after blood loss, and that the brain areas mediating cardiovascular response to challenges such as acute hypovolaemia are not the same areas that regulate resting arterial pressure.
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Affiliation(s)
- L A Henderson
- Department of Anatomy and Histology, The University of Sydney, NSW, Australia
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Yamabe H, Itho K, Yasaka Y, Yokoyama M. Clinical application of cardiac output during ramp exercise calculated using the Fick equation--comparison with the 2-stage bicycle ergometer exercise protocol in the supine position. JAPANESE CIRCULATION JOURNAL 1997; 61:488-94. [PMID: 9225194 DOI: 10.1253/jcj.61.488] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The purpose of this study was to clarify whether the direct Fick method is applicable to the measurement of cardiac output (Q) during ramp exercise. Twelve patients with chronic health failure underwent both a ramp exercise test and a steady-state exercise test. Oxygen intake (VO2), arterial oxygen saturation and mixed venous oxygen saturation were continuously measured using a pulse oximeter and a fiberoptic catheter, and the arteriovenous oxygen difference (a-v O2 diff) and Q were calculated. Both VO2 and a-v O2 diff were significantly lower in the ramp protocol than in the steady-state protocol when they were compared at the same workload. However, the VO2 vs Q relationship and the VO2 vs a-v O2 diff relationship were very similar in the 2 protocols. The difference between Q measured during steady-state exercise and Q calculated at the matched VO2 during ramp exercise was small (3.7 +/- 7.0% and 5.6 +/- 6.6%). The results indicate that, clinically, Q measured by the direct Fick method with simultaneous measurement of VO2 and a-v O2 diff during ramp exercise is a good substitute for the true Q measured by the steady-state protocol. We conclude that Fick Q is applicable to ramp exercise.
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Affiliation(s)
- H Yamabe
- First Department of Internal Medicine, Kobe University School of Medicine, Japan
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HANSON JS, TABAKIN BS. COMPARISON OF THE CIRCULATORY RESPONSE TO UPRIGHT EXERCISE IN 25 "NORMAL" MEN AND 9 DISTANCE RUNNERS. BRITISH HEART JOURNAL 1996; 27:211-9. [PMID: 14268432 PMCID: PMC503302 DOI: 10.1136/hrt.27.2.211] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Tanaka H, Sjöberg BJ, Thulesius O. Cardiac output and blood pressure during active and passive standing. CLINICAL PHYSIOLOGY (OXFORD, ENGLAND) 1996; 16:157-70. [PMID: 8964133 DOI: 10.1111/j.1475-097x.1996.tb00565.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The present study compared the haemodynamic pattern of active and passive standing. We used non-invasive techniques with beat-to-beat evaluation of blood pressure, heart rate and stroke volume. Seven healthy subjects, aged 24-41 (mean 30) years were examined. Finger blood pressure was continuously recorded by volume clamp technique (Finapres), and simultaneous beat-to-beat beat stroke volume was obtained, using an ultrasound Doppler technique, from the product of the valvular area and the aortic flow velocity time integral in the ascending aorta from the suprasternal notch. Measurements were performed at rest, during active standing and following passive tilt (60 degrees). Active standing caused a transient but greater reduction of blood pressure and a higher increase of heart rate than passive tilt during the first 30s (delta mean blood pressure: -39 +/- 10 vs. -16 +/- 7 mmHg, delta heart rate: 35 +/- 8 vs. 12 +/- 7 beats m-1 (active standing vs. passive tilt; P < 0.01). There was a significantly larger increase in cardiac output during active standing (37 +/- 24 vs. 0 +/- 15%, P < 0.01) and a more marked decrease in total peripheral resistance (-58 +/- 11 vs. -16 +/- 17%, P < 0.01). A precipitous rise in intra-abdominal pressure (43 +/- 22 mmHg) could be observed upon rising only in active standing. This was interpreted as an indication of translocation of blood to the thorax. There was no significant difference in haemodynamic changes during the later stage of standing (1-7 min) between both manoeuvres. These results suggest that active standing causes a marked blood pressure reduction in the initial phase which seems to reflect systemic vasodilatation caused by activation of cardiopulmonary baroreflexes, probably due to a rapid shift of blood from the splanchnic vessels in addition to the shift from muscular vessels associated with abdominal and calf muscle contraction. Moreover, the ultrasound Doppler technique was found to be a more adequate method for rapid beat-to-beat evaluation of cardiac output during orthostatic manoeuvres.
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Affiliation(s)
- H Tanaka
- Department of Pediatrics, Osaka Medical College, Japan
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Quinn TJ, Smith SW, Vroman NB, Kertzer R, Olney WB. Physiologic responses of cardiac patients to supine, recumbent, and upright cycle ergometry. Arch Phys Med Rehabil 1995; 76:257-61. [PMID: 7717819 DOI: 10.1016/s0003-9993(95)80612-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Physiological responses were compared in nine stable male cardiac patients (mean +/- standard error (SE): age, 68.3 +/- 8.1 years; height, 172.7 +/- 3.9cm; weight, 72.8 +/- 14.5kg) during stationary cycling in the supine, recumbent, and upright positions. A discontinuous exercise protocol was performed in which each stage included 3 minutes of exercise and 1 minute of recovery. Each subject's workload started at 150kgm.min-1 and increased by 150kgm.min-1 per stage until volitional fatigue. Testing sessions were randomized and performed 1 week apart. Subjects continued their normal medication regimen. All subjects were participants in a community-based cardiac rehabilitation program. Dependent variables were assessed at two different intensities; submaximal (300kgm.min +/- 1) and maximal. A two-way repeated measures ANOVA found no significant differences in systolic blood pressure (SBP), diastolic blood pressure (DBP), minute ventilation (VE), respiratory exchange ratio (R), rate pressure product (RPP), and rating of perceived exertion (RPE) at submaximal (300kgm.min +/- 1) and maximal exercise efforts. Heart rate (HR) was significantly lower (p < or = .05) in the supine position compared with either the upright or recumbent positions during the submaximal workload. In addition, oxygen uptake (VO2) was significantly lower in the supine position at the submaximal workload (p < or = .05) compared with both upright and recumbent. No difference in HR or VO2 was observed at maximal exercise. Regressions of HR on VO2 showed similar slopes and intercepts for supine, recumbent, and upright ergometry.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- T J Quinn
- University of New Hampshire, Department of Kinesiology, Durham 03824, USA
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Preul MC, Long PB, Brown JA, Velasco ME, Weaver MT. Autonomic and histopathological effects of percutaneous trigeminal ganglion compression in the rabbit. J Neurosurg 1990; 72:933-40. [PMID: 2338578 DOI: 10.3171/jns.1990.72.6.0933] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The histopathological and autonomic effects of percutaneous trigeminal ganglion compression for trigeminal neuralgia were studied in New Zealand White rabbits. Drops in mean arterial blood pressure of 38% and in heart rate of 30% were observed during compression (p less than 0.0001). Corneal reflex, pinprick sensation, and mastication strength were intact in 13 of 14 rabbits after compression. These findings resembled the effects of percutaneous compression in humans and suggested that the New Zealand White rabbit is a useful model for the study of percutaneous compression. Trigeminal sensory roots and ganglia from 14 rabbits killed at intervals from 1 to 84 days after percutaneous compression were sectioned and stained using immunoperoxidase for neurofilaments, hematoxylin and eosin, luxol fast blue, and cresyl echt violet. Focal axonal damage and demyelination were present 7 days after compression. No difference could be detected in the perikaryonal distribution of neurofilaments between compressed and control trigeminal ganglia. Focal demyelination and Schwann cell proliferation preceding remyelination were present in the trigeminal sensory root at 84 days. Differential injury of axons compared to trigeminal ganglion cell bodies suggests that axonal regeneration is possible and may contribute to the recovery of motor and sensory function in patients after percutaneous compression.
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Affiliation(s)
- M C Preul
- Department of Neurological Surgery, Montreal Neurological Institute and Hospital, Quebec, Canada
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Challiss RA, Hayes DJ, Petty RF, Radda GK. An investigation of arterial insufficiency in rat hindlimb. A combined 31P-n.m.r. and bloodflow study. Biochem J 1986; 236:461-7. [PMID: 3753459 PMCID: PMC1146862 DOI: 10.1042/bj2360461] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A small animal model of arterial insufficiency is presented which involves unilateral femoral artery ligation and section. Invoked alterations in metabolism and perfusion of the affected muscle mass have been investigated 12 h, 4, 7 and 14 days post-ligation by 31P-n.m.r. and microsphere infusion, both at rest and during isometric muscle contraction at 1 Hz. At rest, the concentration of phosphocreatine was similar to the mean control value (36.0 +/- 1.0 mM) from 4 days post-ligation, but was significantly lower at 12 h (28.5 +/- 3.6 mM). Inorganic phosphate concentrations were significantly elevated for 7 days post-ligation. No significant differences were noted in intramuscular pH. Upon stimulation of the affected muscle mass, a time-dependent improvement in phosphocreatine utilization was observed such that 14 days post-ligation phosphocreatine utilization was not significantly different from mean control values. A similar amelioration was noted for the contraction-induced fall in intramuscular pH. At rest, no significant differences in bloodflow to the muscles of the ligated limb compared with the unaffected contralateral limb were observed. However, isometric contraction of the affected muscle mass resulted in a markedly reduced hyperaemic response 12 h post-ligation. Thereafter, a time-dependent improvement in tissue perfusion during stimulation was observed which paralleled the improvements in phosphocreatine utilization and intramuscular pH changes. The results presented are discussed with respect to the interrelationship between oxygen delivery, high energy phosphate utilization and force maintenance.
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Mense S. Slowly Conducting Afferent Fibers from Deep Tissues: Neurobiological Properties and Central Nervous Actions. PROGRESS IN SENSORY PHYSIOLOGY 6 1986. [DOI: 10.1007/978-3-642-70411-6_4] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Koyama S, Manning JW. Paradoxical cardiovascular response to visceral afferent stimulation in the established spontaneously hypertensive rat. Clin Exp Pharmacol Physiol 1985; 12:37-42. [PMID: 4006310 DOI: 10.1111/j.1440-1681.1985.tb00300.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Afferent splanchnic nerve stimulation with different frequencies in Wistar Kyoto rats caused depressor and pressor responses depending on the frequency employed. Similar visceral afferent activation in spontaneously hypertensive rats caused depressor responses at all frequencies of stimulation. It is suggested that the central integrated mechanisms for activating a cardiovascular state change as evoked by visceral afferents may differ in the established hypertensive rat from that of the normotensive.
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Stridbeck H, Lorelius LE, Pirtle TE. Development of collateral circulation following distal embolization of hepatic artery in pigs. Cardiovasc Intervent Radiol 1984; 7:240-4. [PMID: 6498868 DOI: 10.1007/bf02553142] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The distal hepatic artery was embolized with black polystyrene microspheres (diameters of 50 +/- 10 mu and 200 +/- 25 mu) in 12 pigs. The animals were reexamined from 1 h to 2 weeks after embolization via hepatic angiography and subsequent injection of Microfil, a silicone rubber compound, into the arterial and portal vascular systems of the liver. Dissection of dehydrated and cleared liver specimens under the stereomicroscope demonstrated the presence of arterial collaterals bypassing embolized vessels within 2-3 days after embolization. Collaterals were noted to develop around occlusions in arteries with inner diameters as small as 100 mu.
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Poliner LR, Dehmer GJ, Lewis SE, Parkey RW, Blomqvist CG, Willerson JT. Left ventricular performance in normal subjects: a comparison of the responses to exercise in the upright and supine positions. Circulation 1980; 62:528-34. [PMID: 7398013 DOI: 10.1161/01.cir.62.3.528] [Citation(s) in RCA: 279] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Bevegård S, Eriksson BO, Graff-Lonnevig V, Kraepelien S, Saltin B. Respiratory function, cardiovascular dimensions and work capacity in boys with bronchial asthma. ACTA PAEDIATRICA SCANDINAVICA 1976; 65:289-96. [PMID: 1274562 DOI: 10.1111/j.1651-2227.1976.tb04888.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Twenty boys with bronchial asthma, aged 8-13 years, were studied with regard to the size of their respiratory and circulatory organs and to their excercise tolerance. The boys were divided into two groups (A and B) depending on the severity of their subjective symptoms. Normal values were found for TLC, VC, and FRC in both groups, whereas the group with the most severe asthma had a slightly increased RV. In both groups THb, blood and heart volumes were normal. A quite normal relationship between these variables was observed as well as with work capacity (W170 and VO2 max) with no intergroup differences. Respiratory rate was lower and ventilation was increased in group B, both in submaximal and maximal exercise. Thus, tidal volume in maximal exercise exceeded 50 per cent of vital capacity in this group. These boys also had the highest blood lactate concentration at submaximal and maximal exercise. In half of the boys asthma-like attacks were elicited by the excercise. The symptoms subsided without treatment shortly after work. The frequency and intensity of attacks were similar in the two groups.
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Tallarida G, Baldoni F, Peruzzi G, Semprini A, Sangiorgi M. Cardiovascular and respiratory reflexes elicited by bradykinin acting on receptor sites (K & P) in the muscular circulatory area. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1976; 70:301-14. [PMID: 937136 DOI: 10.1007/978-1-4684-3267-1_36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Björk VO, Böök K, Cernigliaro C, Holmgren A. The Björk-Shiley tilting disc valve in isolated mitral lesions. SCANDINAVIAN JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY 1973; 7:131-48. [PMID: 4127195 DOI: 10.3109/14017437309135555] [Citation(s) in RCA: 46] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Eriksson BO. Cardiac output during exercise in pubertal boys. ACTA PAEDIATRICA SCANDINAVICA. SUPPLEMENT 1971; 217:53-5. [PMID: 5289799 DOI: 10.1111/j.1651-2227.1971.tb05693.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Eriksson I, Sahlstedt B. The development of collateral arteries. An angiographic and microscopic study in the rabbit. SCANDINAVIAN JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY 1971; 5:265-74. [PMID: 5135714 DOI: 10.3109/14017437109134279] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Strubelt O, Back G, Uhl E, Zetler G. Cardiac output, heart rate, and blood pressure as influenced by equi-antiarrhythmic doses of eight antifibrillatory agents. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1971; 271:346-60. [PMID: 4257638 DOI: 10.1007/bf00997124] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Eriksson I. Adrenergic nerve terminals in collateral arteries of the lower extremity. SCANDINAVIAN JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY 1970; 4:225-9. [PMID: 4099760 DOI: 10.3109/14017437009131937] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Shephard RJ. Pulse rate and ventilation as indices of habitual activity. I. Theoretical aspects. ARCHIVES OF ENVIRONMENTAL HEALTH 1967; 15:562-7. [PMID: 6066261 DOI: 10.1080/00039896.1967.10664970] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Hintze A, Kreppel E. Über den Einfluß der Lageänderung auf Herzfrequenz, Blutdruck und Katecholaminausscheidung im Harn bei Säuglingen, Kleinkindern und älteren Kindern. J Mol Med (Berl) 1966. [DOI: 10.1007/bf01716308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Coffman JD. Peripheral collateral blood flow and vascular reactivity in the dog. J Clin Invest 1966; 45:923-31. [PMID: 5913300 PMCID: PMC292771 DOI: 10.1172/jci105407] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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Lacroix E, Leusen I. Splanchnic hemodynamics during induced muscular exercise in the anesthetized dog. ARCHIVES INTERNATIONALES DE PHYSIOLOGIE ET DE BIOCHIMIE 1966; 74:235-50. [PMID: 4168215 DOI: 10.3109/13813456609059904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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