Splanchnic Venous Capacitance in Postural Tachycardia Syndrome

Summary

Postural tachycardia syndrome (POTS) affects ≈3 million young people, characterized by chronic presyncopal symptoms characterized by dizziness, lightheadedness, and orthostatic tachycardia that occur while standing. Across-sectional survey found that 25% of these patients complains that meals rich in carbohydrates are among the factors that further exacerbate POTS's symptoms and cause a myriad of gastrointestinal symptoms. The splanchnic circulation is the largest blood volume reservoir of the human body, storing ≈25% of the total blood volume and contributing to sudden, and large, fluctuations in the stroke volume (SV). The orthostatic changes in systemic hemodynamics are particularly magnified after meals, due to increased blood volume sequestration triggered by the release of gastrointestinal peptides with vasodilatory properties. The purpose of this study is to determine if the worsening orthostatic tachycardia and symptoms after glucose ingestion in POTS patients are due to a greater increase in splanchnic venous capacitance and excessive blood pooling on standing as compare to Healthy controls. The study will also determine if glucose-induced GIP secretion increases splanchnic venous capacitance, orthostatic tachycardia and worsening POTS postprandial symptoms. For this purpose subjects will be further randomized to either saline versus GIP(3-30)NH2 acute infusion, to measure the changes their splanchnic venous capacitance and superior mesenteric arterial flow before and after a 75-g oral glucose challenge during supine and 45-degree head-up tilt positions (orthostatic challenge) for up to 3 hours.

Timeline

Start

2023-02-25

Primary completion

2027-05-31

Completion

2028-06-01

Publications

• Results Jacob G, Costa F, Shannon JR, Robertson RM, Wathen M, Stein M, Biaggioni I, Ertl A, Black B, Robertson D; New Collective Author. The neuropathic postural tachycardia syndrome. N Engl J Med. 2000 Oct 5;343(14):1008-14. doi: 10.1056/NEJM200010053431404.
• Results Shibao C, Arzubiaga C, Roberts LJ 2nd, Raj S, Black B, Harris P, Biaggioni I. Hyperadrenergic postural tachycardia syndrome in mast cell activation disorders. Hypertension. 2005 Mar;45(3):385-90. doi: 10.1161/01.HYP.0000158259.68614.40. Epub 2005 Feb 14.
• Results Prentky RA, Watt NF, Fryer JH. Longitudinal social competence and adult psychiatric symptoms at first hospitalization. Schizophr Bull. 1979;5(2):306-12. doi: 10.1093/schbul/5.2.306.
• Results Bourne KM, Stiles LE, Raj SR, Shibao CA. Do meals affect heart rate and symptoms in postural orthostatic tachycardia syndrome? Clin Auton Res. 2022 Feb;32(1):65-67. doi: 10.1007/s10286-021-00835-0. Epub 2021 Nov 18. No abstract available.
• Results Breier NC, Paranjape SY, Scudder S, Mehr SE, Diedrich A, Flynn CR, Okamoto LE, Hartmann B, Gasbjerg LS, Shibao CA. Worsening Postural Tachycardia Syndrome Is Associated With Increased Glucose-Dependent Insulinotropic Polypeptide Secretion. Hypertension. 2022 May;79(5):e89-e99. doi: 10.1161/HYPERTENSIONAHA.121.17852. Epub 2022 Mar 2.

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