{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T05:56:58Z","timestamp":1789624618482,"version":"build-2803163510"},"reference-count":75,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2024,12,18]],"date-time":"2024-12-18T00:00:00Z","timestamp":1734480000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Introduction: While the diagnosis of postural orthostatic tachycardia syndrome (POTS) is based on heart rate (HR) and blood pressure (BP) criteria, the pathophysiology of POTS is not fully understood as multiple pathophysiological mechanisms have been recognized. Also, cardiac function, being dependent on preload, afterload, contractility, and HR, has not been properly studied. Preload and contractility changes can be inferred from stroke volume index (SVI) changes during a tilt test. Afterload plays a minor role in POTS as a normal BP response is a prerequisite for POTS. Therefore, we analyzed the HR-SVI relation during a tilt test in myalgic encephalomyelitis (ME\/CFS) patients with POTS and compared the data with ME\/CFS patients with a normal HR-BP response and with that of healthy controls (HC). Material and Methods: In ME\/CFS patients with either POTS (n = 233) or a normal HR-BP response (n = 507) and healthy controls (n = 48), we measured SVI (by suprasternal echo), HR, and BP during the tilt. Results: In all ME\/CFS patients, the decrease in SVI was larger compared to HC. In patients with a normal HR-BP response and in POTS patients with a HR increase between 30\u201339 bpm, there was an inverse relationship between the HR increase and SVI decrease during the tilt, compatible with increased venous pooling. In POTS patients with a HR increase \u226540 bpm, this inverse relation was lost, and SVI changes were significantly less compared to POTS patients with a HR increase between 30\u201339 bpm, suggestive of a hyperadrenergic response. Conclusions: In ME\/CFS patients with POTS, two different hemodynamic profiles can be observed: in patients with a limited HR increase, mainly increased venous pooling is observed, while in patients with a large (\u2265 40 bpm) HR increase the data are suggestive of a hyperadrenergic response. These two different profiles may have different therapeutic implications.<\/jats:p>","DOI":"10.3390\/jcm13247726","type":"journal-article","created":{"date-parts":[[2024,12,18]],"date-time":"2024-12-18T09:43:03Z","timestamp":1734514983000},"page":"7726","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Two Different Hemodynamic Responses in ME\/CFS Patients with Postural Orthostatic Tachycardia Syndrome During Head-Up Tilt Testing"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2570-0914","authenticated-orcid":false,"given":"C. (Linda) M. C.","family":"van Campen","sequence":"first","affiliation":[{"name":"Stichting CardioZorg, Kraayvel 5, 1171 JE Badhoevedorp, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3586-2677","authenticated-orcid":false,"given":"Peter C.","family":"Rowe","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, John Hopkins University School of Medicine, Baltimore, MD 21205, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Frans C.","family":"Visser","sequence":"additional","affiliation":[{"name":"Stichting CardioZorg, Kraayvel 5, 1171 JE Badhoevedorp, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,12,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"102836","DOI":"10.1016\/j.autneu.2021.102836","article-title":"Postural orthostatic tachycardia syndrome (pots): Priorities for pots care and research from a 2019 national institutes of health expert consensus meeting\u2014Part 2","volume":"235","author":"Raj","year":"2021","journal-title":"Auton. 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