Orthostatic tolerance, cerebral oxygenation, and blood velocity in humans with sympathetic failure
| Autor: | Jacques W.M. Lenders, M.P.M. Harms, Willy N.J.M. Colier, N. H. Secher, Wouter Wieling, J. J. van Lieshout |
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| Přispěvatelé: | Other departments |
| Rok vydání: | 2000 |
| Předmět: |
Adult
Male Mean arterial pressure Ultrasonography Doppler Transcranial Hemodynamics Blood Pressure Non-invasive intravital spectrophotometric determination of tissue oxygenation Orthostatic vital signs Hypotension Orthostatic The sympathoadrenal system and primary hypertension medicine.artery Medicine Humans Het sympathoadrenale systeem en primaire hypertensie Cerebral perfusion pressure Cardiac Output Aged Advanced and Specialized Nursing business.industry Brain Oxygenation Middle Aged Non-invasieve intravitaal spectrofotometrische bepaling van weefseloxygenatie Oxygen Blood pressure Cerebral blood flow Autonomic Nervous System Diseases Anesthesia Cerebrovascular Circulation Middle cerebral artery Female Neurology (clinical) Cardiology and Cardiovascular Medicine business Blood Flow Velocity |
| Zdroj: | Stroke, 31, pp. 1608-1614 Stroke, 31, 1608-1614 Stroke; a journal of cerebral circulation, 31(7), 1608-1614. Lippincott Williams and Wilkins |
| ISSN: | 0039-2499 |
| Popis: | Background and Purpose —Patients with orthostatic hypotension due to sympathetic failure become symptomatic when standing, although their capability to maintain cerebral blood flow is reported to be preserved. We tested the hypothesis that in patients with sympathetic failure, orthostatic symptoms reflect reduced cerebral perfusion with insufficient oxygen supply. Methods —This study addressed the relationship between orthostatic tolerance, mean cerebral artery blood velocity (V mean , determined by transcranial Doppler ultrasonography), oxygenation (oxyhemoglobin [O 2 Hb], determined by near-infrared spectroscopy), and mean arterial pressure at brain level (MAP MCA , determined by finger arterial pressure monitoring [Finapres]) in 9 patients (aged 37 to 70 years; 4 women) and their age- and sex-matched controls during 5 minutes of standing. Results —Supine MAP MCA (108±14 versus 86±14 mm Hg) and V mean (84±21 versus 62±13 cm · s −1 ) were higher in the patients. After 5 minutes of standing, MAP MCA was lower in the patients (31±14 versus 72±14 mm Hg), as was V mean (51±8 versus 59±9 cm · s −1 ), with a larger reduction in O 2 Hb (−11.6±4 versus −6.7±4.5 μmol · L −1 ). Four patients terminated standing after 1 to 3.5 minutes. In these symptomatic patients, the orthostatic fall in V mean was greater (45±6 versus 64±10 cm · s −1 ), and the orthostatic decrease in O 2 Hb (−12.0±3.3 versus −7.6±3.9 μmol · L −1 ) tended to be larger. The reduction in MAP MCA was larger after 10 seconds of standing, and MAP MCA was lower after 1 minute (25±8 versus 40±6 mm Hg). Conclusions —In patients with sympathetic failure, the orthostatic reduction in cerebral blood velocity and oxygenation is larger. Patients who become symptomatic within 5 minutes of standing are characterized by a pronounced orthostatic fall in blood pressure, cerebral blood velocity, and oxygenation manifest within the first 10 seconds of standing. |
| Databáze: | OpenAIRE |
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