Raised Cerebrovascular Resistance in Idiopathic Orthostatic Intolerance: Evidence for Sympathetic Vasoconstriction
Abstract
Abstract —Patients with idiopathic orthostatic intolerance (IOI) exhibit symptoms suggestive of cerebral hypoperfusion and an excessive decrease in cerebral blood flow associated with standing despite sustained systemic blood pressure. In 9 patients (8 women and 1 man aged 22 to 48 years) with IOI, we tested the hypothesis that volume loading (2000 cc normal saline) and α-adrenoreceptor agonism improve systemic hemodynamics and cerebral perfusion and that the decrease in cerebral blood flow with head-up tilt (HUT) could be attenuated by α-adrenoreceptor blockade with phentolamine. At 5 minutes of HUT, volume loading (−20±3.2 bpm) and phenylephrine (−18±3.4 bpm) significantly reduced upright heart rate compared with placebo; the effect was diminished at the end of HUT. Phentolamine substantially increased upright heart rate at 5 minutes (20±3.7 bpm) and at the end of HUT (14±5 bpm). With placebo, mean cerebral blood flow velocity decreased by 33±6% at the end of HUT. This decrease in cerebral blood flow with HUT was attenuated by all 3 interventions. We conclude that in patients with IOI, HUT causes a substantial decrease in cerebrovascular blood flow velocity. The decrease in blood flow velocity with HUT can be attenuated with interventions that improve systemic hemodynamics and therefore decrease reflex sympathetic activation. Moreover, α-adrenoreceptor blockade also blunts the decrease in cerebral blood flow with HUT but at the price of deteriorated systemic hemodynamics. These observations may suggest that in patients with IOI, excessive sympathetic activity contributes to the paradoxical decrease in cerebral blood flow with upright posture.
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POTS patients have significantly greater decreases in thoracic and cerebral blood flow when compared to healthy controls during tilt.
“Other studies have also demonstrated that POTS patients have significantly greater decreases in thoracic and cerebral blood flow when compared to healthy controls during tilt (21, 23, 25-27).”
From Postural orthostatic tachycardia syndrome: mechanisms and new therapies (2020) · cites this paper as [26]
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Cites
Cerebral Arterial Diameters during Changes in Blood Pressure and Carbon Dioxide during Craniotomy
Giller, C. A., Bowman, G., Dyer, H., Mootz, L., & Krippner, W. J. (1993) · Neurosurgery · doi:10.1227/00006123-199305000-00006 · Cited by 658 · see citing works
Idiopathic postural orthostatic tachycardia syndrome: An attenuated form of acute pandysautonomia?
Schondorf, R., & Low, P. A. (1993) · Neurology · doi:10.1212/wnl.43.1_part_1.132 · Cited by 548 · see citing works
Primer on Cerebrovascular Diseases
(1997) · Elsevier eBooks · doi:10.1016/b978-0-12-743170-3.x5000-6 · Cited by 253 · see citing works
Hyperdynamic ß-Adrenergic Circulatory State
Frohlich, E. D. (1969) · Archives of Internal Medicine · doi:10.1001/archinte.1969.00300110003001 · Cited by 239 · see citing works
Effects of volume loading and pressor agents in idiopathic orthostatic tachycardia
Jacob, G., Shannon, J. R., Black, B., Biaggioni, I., Mosqueda-Garcia, R., Robertson, R. M., & Robertson, D. (1997) · Circulation · doi:10.1161/01.cir.96.2.575 · Cited by 206 · see citing works
Self-citationStreeten, D. H. P., Anderson, G. H., Richardson, R., & THOMAS, F. D. (1988) · PubMed · Cited by 183 · see citing works
Hyperdynamic beta-adrenergic circulatory state. Increased beta-receptor responsiveness
Frohlich, E. D. (1969) · Archives of Internal Medicine · doi:10.1001/archinte.123.1.1 · Cited by 171 · see citing works
Streeten, D. H. (1990) · Journal of Clinical Investigation · doi:10.1172/jci114878 · Cited by 170 · see citing works
Hyperdynamic Beta-Adrenergic Circulatory State
Frohlich, E. D. (1966) · Archives of Internal Medicine · doi:10.1001/archinte.1966.03870110006002 · Cited by 169 · see citing works
Hypovolemia in syncope and orthostatic intolerance role of the renin-angiotensin system
Jacob, G., Robertson, D., Mosqueda-Garcia, R., Ertl, A. C., Robertson, R. M., & Biaggioni, I. (1997) · The American Journal of Medicine · doi:10.1016/s0002-9343(97)00133-2 · Cited by 164 · see citing works
Self-citationPatterns of plasma levels of catechols in neurogenic orthostatic hypotension
Goldstein, D. S., Polinsky, R. J., Garty, M., Robertson, D., Brown, R. T., Biaggioni, I., Stull, R., & Kopin, I. J. (1989) · Annals of Neurology · doi:10.1002/ana.410260410 · Cited by 162 · see citing works
Self-citationFOUAD, F. M., TADENA-THOME, L., BRAVO, E. L., & TARAZI, R. C. (1986) · Annals of Internal Medicine · doi:10.7326/0003-4819-104-3-298 · Cited by 154 · see citing works
Schondorf, R., Benoit, J., & Wein, T. H. (1997) · Stroke · doi:10.1161/01.str.28.8.1564 · Cited by 112 · see citing works
Rosen, S. G., & Cryer, P. E. (1982) · The American Journal of Medicine · doi:10.1016/0002-9343(82)90559-9 · Cited by 104 · see citing works
HOELDTKE, R. D., & DAVIS, K. M. (1991) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jcem-73-1-132 · Cited by 85 · see citing works
Sympathotonic orthostatic hypotension
Hoeldtke, R. D., Dworkin, G. E., Gaspar, S. R., & Israel, B. C. (1989) · Neurology · doi:10.1212/wnl.39.1.34 · Cited by 69 · see citing works
Jacob, G., Atkinson, D. S., Jordan, J., Shannon, J. R., Furlan, R., Black, B. K., & Robertson, D. (1999) · The American Journal of Medicine · doi:10.1016/s0002-9343(98)00364-7 · Cited by 65 · see citing works
Self-citationEstimation of intrasynaptic norepinephrine concentrations in humans.
Goldstein, D. S., Zimlichman, R., Stull, R., Keiser, H. R., & Kopin, I. J. (1986) · Hypertension · doi:10.1161/01.hyp.8.6.471 · Cited by 51 · see citing works
Transcranial Doppler Ultrasonography during Head-Upright Tilt-Table Testing
FREDMAN, C. S., Biermann, K. M., Patel, V., Uppstrom, E. L., & Auer, A. I. (1995) · Annals of Internal Medicine · doi:10.7326/0003-4819-123-11-199512010-00007 · Cited by 35 · see citing works
The physiological conundrum of hyperadrenergic orthostatic intolerance.
Jordan, J., Shannon, J., & Robertson, D. (1997) · PubMed · Cited by 16 · see citing works
Self-citationOverview of Cerebrovascular Hemodynamics
Hurn, P. D., & Traystman, R. J. (1997) · Primer on Cerebrovascular Diseases · doi:10.1016/b978-012743170-3.50012-1 · Cited by 16 · see citing works
Goadsby, P. J., & Edvinsson, L. I. (1997) · Primer on Cerebrovascular Diseases · doi:10.1016/b978-012743170-3.50017-0 · Cited by 8 · see citing works
Iwase, S., Mano, T., Saito, M., & Ishida, G. (1991) · Journal of the Autonomic Nervous System · doi:10.1016/0165-1838(91)90043-3 · Cited by 8 · see citing works
Overview of Cerebrovascular Hemodynamics
Hurn, P. D., & Traystman, R. J. (1997) · Primer on Cerebrovascular Diseases · doi:10.1016/b978-012743170-3/50012-1 · Cited by 6 · see citing works
Extrinsic InnervationTransmitters, Receptors, and Functions—The Sympathetic Nervous System
Goadsby, P. J., & Edvinsson, L. I. (1997) · Primer on Cerebrovascular Diseases · doi:10.1016/b978-012743170-3/50017-0 · Cited by 1 · see citing works
Flagged first, then by citations
Research works printed but not linked: 4
- Fouad FM, Tadena-Thome L, Bravo EL, Tarazi RC. Idiopathic hypo- volemia. Ann Intern Med. 1986;104:298 -303.
- Hoeldtke RD, Dworkin GE, Gaspar SR, Israel BC. Sympathotonic ortho- static hypotension: a report of four cases. Neurology. 1989;39:34 -40.
- Jacob G, Atkinson D, Jordan J, Shannon JR, Furlan R, Black BK, Robertson D. Augmented regional cerebrovascular resistance with upright posture in idiopathic orthostatic intolerance. Am J Med. 1998. In press.
- Novak P, Novak V, Low PA, Petty GW. Transcranial Doppler evaluation in disorders of reduced orthostatic tolerance. In: Low PA, ed. Clinical Autonomic Disorders. Philadelphia, Pa: Lippincott-Raven Publishers; 1997:349 -368.
Cited by
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Cerebral blood flow and metabolism during exercise.
Ide, K., & Secher, N. (2000) · Progress in neurobiology · doi:10.1016/s0301-0082(99)00057-x · Cited by 60 · see citing works
The neuropathic postural tachycardia syndrome
Jacob, G., Costa, F., Shannon, J. R., Robertson, R. M., Wathen, M., Stein, M., Biaggioni, I., Ertl, A., Black, B., & Robertson, D. (2000) · New England Journal of Medicine · doi:10.1056/nejm200010053431404 · Cited by 398 · see citing works
Self-citationDysautonomia in the joint hypermobility syndrome
Gazit, Y., Nahir, A. M., Grahame, R., & Jacob, G. (2003) · The American Journal of Medicine · doi:10.1016/s0002-9343(03)00235-3 · Cited by 390 · see citing works
Postural tachycardia syndrome—current experience and concepts
Mathias, C. J., Low, D. A., Iodice, V., Owens, A. P., Kirbis, M., & Grahame, R. (2012) · Nature Reviews Neurology · doi:10.1038/nrneurol.2011.187 · Cited by 251 · see citing works
Water drinking as a treatment for orthostatic syndromes
Shannon, J. R., Diedrich, A., Biaggioni, I., Tank, J., Robertson, R. M., Robertson, D., & Jordan, J. (2002) · The American Journal of Medicine · doi:10.1016/s0002-9343(02)01025-2 · Cited by 233 · see citing works
Self-citationPostural tachycardia syndrome – Diagnosis, physiology, and prognosis
Arnold, A. C., Ng, J., & Raj, S. R. (2018) · Autonomic Neuroscience · doi:10.1016/j.autneu.2018.02.005 · Cited by 186 · see citing works
Autonomic Neural Control of the Cerebral Vasculature
Ogoh, S., Brothers, R. M., Eubank, W. L., & Raven, P. B. (2008) · Stroke · doi:10.1161/strokeaha.107.510008 · Cited by 172 · see citing works
Jordan, J., Shannon, J. R., Diedrich, A., Black, B. K., da Costa, F. A. A., Robertson, D., & Biaggioni, I. (2000) · Hypertension · doi:10.1161/01.hyp.36.3.383 · Cited by 161 · see citing works
Self-citationThe hemodynamic and neurohumoral phenotype of postural tachycardia syndrome
Garland, E. M., Raj, S. R., Black, B. K., Harris, P. A., & Robertson, D. (2007) · Neurology · doi:10.1212/01.wnl.0000267663.05398.40 · Cited by 159 · see citing works
Self-citationWIRTH, K. J., & Scheibenbogen, C. (2020) · Autoimmunity Reviews · doi:10.1016/j.autrev.2020.102527 · Cited by 137 · see citing works
Ainslie, P. N., Ashmead, J. C., Ide, K., Morgan, B. J., & Poulin, M. J. (2005) · The Journal of Physiology · doi:10.1113/jphysiol.2005.087320 · Cited by 136 · see citing works
Postural orthostatic tachycardia syndrome: mechanisms and new therapies
Mar, P. L., & Raj, S. R. (2020) · Annual Review of Medicine · doi:10.1146/annurev-med-041818-011630 · Cited by 122 · see citing works
Orthostatic hypertension: when pressor reflexes overcompensate
Fessel, J. P., & Robertson, D. (2006) · Nature Reviews Nephrology · doi:10.1038/ncpneph0228 · Cited by 113 · see citing works
Self-citationNorepinephrine transporter function and human cardiovascular disease
Schroeder, C., & Jordan, J. (2012) · American Journal of Physiology-Heart and Circulatory Physiology · doi:10.1152/ajpheart.00492.2012 · Cited by 109 · see citing works
Self-citationOcon, A. J., Medow, M. S., Taneja, I., Clarke, D., & Stewart, J. M. (2009) · American Journal of Physiology-Heart and Circulatory Physiology · doi:10.1152/ajpheart.00138.2009 · Cited by 105 · see citing works
Nonpharmacologic Management of Orthostatic Hypotension: A Systematic Review
Mills, P. B., Fung, C. K.-Y., Travlos, A., & Krassioukov, A. V. (2014) · Archives of Physical Medicine and Rehabilitation · doi:10.1016/j.apmr.2014.09.028 · Cited by 83 · see citing works
Freitas, J., Santos, R., Azevedo, E., Costa, O., Carvalho, M., & Falcão de Freitas, A. (2000) · Clinical Autonomic Research · doi:10.1007/bf02281112 · Cited by 78 · see citing works
Fisher, J. P., Ogoh, S., Young, C. N., Raven, P. B., & Fadel, P. J. (2008) · Journal of Applied Physiology · doi:10.1152/japplphysiol.00118.2008 · Cited by 70 · see citing works
Kanjwal, K., Karabin, B. L., Kanjwal, Y., & Grubb, B. P. (2010) · International Journal of Medical Sciences · doi:10.7150/ijms.7.62 · Cited by 66 · see citing works
Orthostatic Intolerance: A Disorder of Young Women
Ali, Y. S., Daamen, N., Jacob, G., Jordan, J., Shannon, J. R., Biaggioni, I., & Robertson, D. (2000) · Obstetrical & Gynecological Survey · doi:10.1097/00006254-200004000-00025 · Cited by 64 · see citing works
Self-citationFamilial orthostatic tachycardia due to norepinephrine transporter deficiency
ROBERTSON, D., FLATTEM, N., TELLIOGLU, T., CARSON, R., GARLAND, E., SHANNON, J. R., JORDAN, J., JACOB, G., BLAKELY, R. D., & BIAGGIONI, I. (2001) · Annals of the New York Academy of Sciences · doi:10.1111/j.1749-6632.2001.tb03703.x · Cited by 64 · see citing works
Self-citationVianna, L. C., Deo, S. H., Jensen, A. K., Holwerda, S. W., Zimmerman, M. C., & Fadel, P. J. (2015) · American Journal of Physiology-Heart and Circulatory Physiology · doi:10.1152/ajpheart.00343.2014 · Cited by 60 · see citing works
Kanjwal, K., Saeed, B., Karabin, B. L., Kanjwal, Y., & Grubb, B. P. (2010) · PubMed Central · Cited by 59 · see citing works
LeMarbre, G., Stauber, S., Khayat, R., Puleo, D. S., Skatrud, J. B., & Morgan, B. J. (2003) · The Journal of Physiology · doi:10.1113/jphysiol.2003.046987 · Cited by 58 · see citing works
Cerebral Autoregulation in Orthostatic Intolerance
Schondorf, R., Benoit, J., & Stein, R. D. (2001) · Annals of the New York Academy of Sciences · doi:10.1111/j.1749-6632.2001.tb03702.x · Cited by 58 · see citing works
Neuronal and hormonal perturbations in postural tachycardia syndrome
Mar, P. L., & Raj, S. R. (2014) · Frontiers in Physiology · doi:10.3389/fphys.2014.00220 · Cited by 52 · see citing works
Autonomic Control of Cerebral Circulation
Ogoh, S. (2008) · Medicine & Science in Sports & Exercise · doi:10.1249/mss.0b013e318180bc6f · Cited by 49 · see citing works
Kanjwal, K., Saeed, B., Karabin, B., Kanjwal, Y., & Grubb, B. P. (2011) · Cardiology Journal · doi:10.5603/cj.2011.0008 · Cited by 46 · see citing works
Circulating norepinephrine and cerebrovascular control in conscious humans
Kimmerly, D. S., Tutungi, E., Wilson, T. D., Serrador, J. M., Gelb, A. W., Hughson, R. L., & Shoemaker, J. K. (2003) · Clinical Physiology and Functional Imaging · doi:10.1046/j.1475-0961.2003.00507.x · Cited by 45 · see citing works
Cerebral autoregulation is preserved in postural tachycardia syndrome
Schondorf, R., Benoit, J., & Stein, R. (2005) · Journal of Applied Physiology · doi:10.1152/japplphysiol.00225.2005 · Cited by 38 · see citing works
Acute effect of water on blood pressure
Jordan, J. (2002) · Clinical Autonomic Research · doi:10.1007/s10286-002-0055-5 · Cited by 37 · see citing works
Self-citationEffect of water drinking on sympathetic nervous activity and blood pressure
Jordan, J. (2005) · Current Hypertension Reports · doi:10.1007/s11906-005-0050-z · Cited by 37 · see citing works
Self-citationEndothelial NO Synthase Polymorphisms and Postural Tachycardia Syndrome
Garland, E. M., Winker, R., Williams, S. M., Jiang, L., Stanton, K., Byrne, D. W., Biaggioni, I., Cascorbi, I., Phillips, J. A., Harris, P. A., et al. (2005) · Hypertension · doi:10.1161/01.hyp.0000185462.08685.da · Cited by 35 · see citing works
Self-citationChanges in cerebral oxygenation and blood flow during LBNP in spinal cord-injured individuals
Houtman, S., Serrador, J. M., Colier, W. N. J. M., Strijbos, D., Shoemaker, J. K., & Hopman, M. T. E. (2001) · Journal of Applied Physiology · doi:10.1152/jappl.2001.91.5.2199 · Cited by 28 · see citing works
Weiss, A. T., Beloosesky, Y., Grossman, A., Schlesinger, A., Koren‐Morag, N., & Grossman, E. (2016) · PubMed Central · doi:10.11909/j.issn.1671-5411.2016.03.004 · Cited by 22 · see citing works
Furlan, R., Magatelli, R., Palazzolo, L., Rimoldi, A., Colombo, S., & Porta, A. (2001) · Autonomic Neuroscience · doi:10.1016/s1566-0702(01)00271-5 · Cited by 21 · see citing works
Primary biliary cirrhosis is associated with falls and significant fall related injury
Frith, J., Kerr, S., Robinson, L., Elliott, C., Ghazala, C., Wilton, K., Pairman, J., Jones, D. E. J., & Newton, J. L. (2010) · QJM · doi:10.1093/qjmed/hcp188 · Cited by 21 · see citing works
Clinical features of hyperadrenergic postural tachycardia syndrome in children
Zhang, Q., Chen, X., Li, J., & Du, J. (2014) · Pediatrics International · doi:10.1111/ped.12392 · Cited by 20 · see citing works
Feeling Lightheaded: The Role of Cerebral Blood Flow
Bresseleers, J., Diest, I. V., Peuter, S. D., Verhamme, P. B., & den Bergh, O. V. (2010) · Psychosomatic Medicine · doi:10.1097/psy.0b013e3181e68e94 · Cited by 20 · see citing works
Robertson, D., Shannon, J. R., Biaggioni, I., Ertl, A. C., Diedrich, A., Carson, R. P., Furlan, R., Jacob, G., Jordan, J., & and the Cygnus Research Team (2000) · Pflügers Archiv - European Journal of Physiology · doi:10.1007/s004240000353 · Cited by 19 · see citing works
Self-citationJordan, J., Shannon, J. R., Jacob, G., Pohar, B., & Robertson, D. (1999) · The American Journal of the Medical Sciences · doi:10.1016/s0002-9629(15)40642-1 · Cited by 14 · see citing works
Self-citationter Laan, M., van Dijk, J. M. C., Elting, J. J., Fidler, V., & Staal, M. J. (2010) · Acta Neurochirurgica · doi:10.1007/s00701-010-0678-6 · Cited by 13 · see citing works
Dopamine-β-hydroxylase in postural tachycardia syndrome
Garland, E. M., Black, B. K., Harris, P. A., & Robertson, D. (2007) · American Journal of Physiology-Heart and Circulatory Physiology · doi:10.1152/ajpheart.01389.2006 · Cited by 12 · see citing works
Self-citationBohora, S. (2010) · PubMed Central · Cited by 11 · see citing works
Lin, C.-J., Chu, Y.-K., & Chern, C. (2014) · Journal of the Chinese Medical Association · doi:10.1016/j.jcma.2014.01.005 · Cited by 9 · see citing works
Landero, J. (2014) · PubMed Central · Cited by 7 · see citing works
Fontenele, J. B., & Felix, F. H. C. (2009) · Journal of Musculoskeletal Pain · doi:10.1080/10582450802679904 · Cited by 7 · see citing works
Kanjwal, K., Karabin, B. L., Kanjwal, Y., & Grubb, B. P. (2009) · Cardiology Research and Practice · doi:10.4061/2009/187543 · Cited by 6 · see citing works
Hyperadrenergic Postural Tachycardia Syndrome
Vincent, S., & Robertson, D. (2004) · Elsevier eBooks · doi:10.1016/b978-012589762-4/50094-3 · Cited by 6 · see citing works
Self-citationPathophysiology and Classification of PoTS
Lloyd, M., & Raj, S. (2020) · Postural Tachycardia Syndrome · doi:10.1007/978-3-030-54165-1_5 · Cited by 4 · see citing works
Cerebral Hemodynamics in the Elderly
Serrador, J. M., Milberg, W., & Lipsitz, L. A. (2005) · Humana Press eBooks · doi:10.1385/1-59259-824-2:075 · Cited by 4 · see citing works
The Cardiovascular Dizziness Connection
Serrador, J. M. (2018) · Elsevier eBooks · doi:10.1016/b978-0-323-55136-6.00015-0 · Cited by 1 · see citing works
Selektive Hemmung der Noradrenalin-Wiederaufnahme als humanes Modell für orthostatische Intoleranz
Schröder, C. (2003) · edoc Publication server (Humboldt University of Berlin) · doi:10.18452/14846
Water Ingestion As Prophylaxis Against Syncope: Fact or Fancy?
Jordan, J. (2006) · Springer eBooks · doi:10.1007/88-470-0371-7_82
Self-citationFisher, J. P., Ogoh, S., Young, C. N., Raven, P. B., Paul, J. H., Robertson, A. D., Edgell, H., Hughson, R. L., Bráz, I. D., Keiser, S., et al. (2015)
The Role of the Sympathetic Nervous System on Cerebral Blood Flow Regulation
Purkayastha, S. (2010) · Digital Commons @ UNT Health Science Center
- Authors
- Jordan, J., Shannon, J. R., Black, B. K., Paranjape, S. Y., Barwise, J., & Robertson, D.
- Affiliations
- Vanderbilt University (US)
- Venue
- Hypertension
- Published
- 1998-10
- Volume
- 32
- Issue
- 4
- Pages
- 699-704
- ISSN
- 0194-911X (ISSN-L)
- 1524-4563
- OpenAlex
- W2170065177
- Cited by
- 56
- References
- 24
- Citations by year
- 2020: 2 · 2019: 1 · 2018: 2 · 2016: 1 · 2015: 2 · 2014: 5 · 2012: 1
- FWCI
- 4.08
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Hypertension (publishedVersion)
- PubMed (publishedVersion)
- Funders
- National Institutes of Health (5r01hl044589-05)
- National Heart, Lung, and Blood Institute (HL-44589, P01HL056693, P01 HL-56693)
- National Center for Research Resources (RR00095)
- Topics
- Health Sciences › Medicine › Surgery › Cardiovascular Syncope and Autonomic Disorders
- Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › Heart Rate Variability and Autonomic Control
- Life Sciences › Neuroscience › Neurology › Vestibular and auditory disorders
- Keywords
- cerebrovascular resistance, cerebral blood flow, head-up tilt, volume expansion, phentolamine, phenylephrine, heart rate, reflex sympathetic activation, cerebral hypoperfusion, systemic hemodynamics
- MeSH terms
- Adrenergic alpha-Agonists, Adrenergic alpha-Antagonists, Adult, Cerebrovascular Circulation, Female, Hemodynamics, Humans, Hypotension, Orthostatic, Male, Middle Aged, Phentolamine, Phenylephrine, Posture, Ultrasonography, Doppler, Transcranial
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