{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,13]],"date-time":"2026-04-13T01:03:23Z","timestamp":1776042203098,"version":"3.50.1"},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"4","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1998,4,1]]},"abstract":"<jats:p>1. The initial circulatory adjustments induced by head-up tilt and tilt-back were investigated in six healthy subjects (aged 30\u201358 years) and six patients with orthostatic hypotension due to pure autonomic failure (aged 33\u201365 years).<\/jats:p>\n               <jats:p>2. Continuous responses of finger arterial pressure and heart rate were recorded by Finapres. A pulse contour algorithm applied to the arterial pressure waveform was used to compute stroke volume responses.<\/jats:p>\n               <jats:p>3. In the healthy subjects, head-up tilt induced gradual circulatory adjustments. After 1 min upright stroke volume and cardiac output had decreased by 39 \u00b1 9% and 26 \u00b1 10% respectively. Little change in mean blood pressure at heart level (+1 \u00b1 7 mmHg) indicated that systemic vascular resistance had increased by 39 \u00b1 24%. The gradual responses to head-up tilt contrasted with the pronounced and rapid circulatory responses upon tilt-back. After 2\u20133 s a rapid increase in stroke volume (from 62 \u00b1 8% to 106 \u00b1 10%) and cardiac output (from 81 \u00b1 11% to 118 \u00b1 20%) was observed with an overshoot of mean arterial pressure above supine control values of 16 \u00b1 3 mmHg at 7 s. In the patients a progressive fall in blood pressure on head-up tilt was observed. After 1 min upright mean blood pressure had decreased by 59 \u00b1 8 mmHg. No change in systemic vascular resistance and a larger decrease in stroke volume (60 \u00b1 7%) and cardiac output (53 \u00b1 8%) were found. On tilt-back a gradual recovery of blood pressure was observed.<\/jats:p>\n               <jats:p>4. In healthy humans upon head-up tilt neural compensatory mechanisms are very effective in maintaining arterial pressure at heart level. The gradual circulatory adjustments to head-up tilt in healthy subjects contrast with the pronounced and abrupt circulatory changes on tilt-back. In patients with a lack of neural circulatory reflex adjustments, gradual blood pressure decreases to head-up tilt and gradual increases to tilt-back are observed.<\/jats:p>","DOI":"10.1042\/cs0940347","type":"journal-article","created":{"date-parts":[[2015,8,7]],"date-time":"2015-08-07T11:40:13Z","timestamp":1438947613000},"page":"347-352","update-policy":"https:\/\/doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":41,"title":["Dynamics of Circulatory Adjustments to Head-Up Tilt and Tilt-Back in Healthy and Sympathetically Denervated Subjects"],"prefix":"10.1042","volume":"94","author":[{"given":"W.","family":"Wieling","sequence":"first","affiliation":[{"name":"University of Amsterdam, Department of Internal Medicine, Academic Medical Centre, PO Box 22700, 1100 DE, Amsterdam, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"J. J.","family":"Van Lieshout","sequence":"additional","affiliation":[{"name":"University of Amsterdam, Department of Internal Medicine, Academic Medical Centre, PO Box 22700, 1100 DE, Amsterdam, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"A. D. J.","family":"Ten Harkel","sequence":"additional","affiliation":[{"name":"University of Amsterdam, Department of Internal Medicine, Academic Medical Centre, PO Box 22700, 1100 DE, Amsterdam, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"288","container-title":["Clinical Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/clinsci\/article-pdf\/94\/4\/347\/466820\/cs0940347.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/clinsci\/article-pdf\/94\/4\/347\/466820\/cs0940347.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,12,1]],"date-time":"2021-12-01T23:14:21Z","timestamp":1638400461000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/clinsci\/article\/94\/4\/347\/76901\/Dynamics-of-Circulatory-Adjustments-to-Head-Up"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1998,4,1]]},"references-count":0,"journal-issue":{"issue":"4","published-print":{"date-parts":[[1998,4,1]]}},"URL":"https:\/\/doi.org\/10.1042\/cs0940347","relation":{},"ISSN":["0143-5221","1470-8736"],"issn-type":[{"value":"0143-5221","type":"print"},{"value":"1470-8736","type":"electronic"}],"subject":[],"published":{"date-parts":[[1998,4,1]]}}}