Diurnal variability in orthostatic tachycardia: implications for the postural tachycardia syndrome
Open accessAbstract
Patients with POTS (postural tachycardia syndrome) have excessive orthostatic tachycardia (>30 beats/min) when standing from a supine position. HR (heart rate) and BP (blood pressure) are known to exhibit diurnal variability, but the role of diurnal variability in orthostatic changes of HR and BP is not known. In the present study, we tested the hypothesis that there is diurnal variation of orthostatic HR and BP in patients with POTS and healthy controls. Patients with POTS (n=54) and healthy volunteers (n=26) were admitted to the Clinical Research Center. Supine and standing (5 min) HR and BP were obtained in the evening on the day of admission and in the following morning. Overall, standing HR was significantly higher in the morning (102±3 beats/min) than in the evening (93±2 beats/min; P<0.001). Standing HR was higher in the morning in both POTS patients (108±4 beats/min in the morning compared with 100±3 beats/min in the evening; P=0.012) and controls (89±3 beats/min in the morning compared with 80±2 beats/min in the evening; P=0.005) when analysed separately. There was no diurnal variability in orthostatic BP in POTS. A greater number of subjects met the POTS HR criterion in the morning compared with the evening (P=0.008). There was significant diurnal variability in orthostatic tachycardia, with a great orthostatic tachycardia in the morning compared with the evening in both patients with POTS and healthy subjects. Given the importance of orthostatic tachycardia in diagnosing POTS, this diurnal variability should be considered in the clinic as it may affect the diagnosis of POTS.
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
It is physiologically normal for orthostatic tachycardia to vary slightly from day to day and for diurnal variability to exist such that greater orthostatic tachycardia occurs in the morning than later in the day.
“It is physiologically normal for orthostatic tachycardia to vary slightly from day to day and for diurnal variability to exist such that greater orthostatic tachycardia occurs in the morning than later in the day.11”
From Diagnosis and management of postural orthostatic tachycardia syndrome (2022) · cites this paper as [11]
The Discussion (page not provided) describes greater morning orthostatic tachycardia in both healthy controls and patients with POTS, and suggests the morning increase is a normal physiological phenomenon. The study compared evening measurements with those on the following morning; it does not establish that orthostatic tachycardia normally varies slightly from day to day. (LLM, conf=0.88)
Experimental — accuracy not yet measuredGiven the substantial diurnal variability, morning assessments will likely be more sensitive for diagnosing POTS.
“Given the substantial diurnal variability, with greater upright heart rate and orthostatic tachycardia in the morning, morning assessments will likely be more sensitive.11”
From Diagnosis and management of postural orthostatic tachycardia syndrome (2022) · cites this paper as [11]
Orthostatic tachycardia is more pronounced in the morning.
“Orthostatic tachycardia is more pronounced in the morning, and the active stand test (or HUT) should be performed in the morning when possible (93).”
From Postural Orthostatic Tachycardia Syndrome (2019) · cites this paper as [93]
The orthostatic tachycardia in POTS is exaggerated in the morning compared with the evening.
“The orthostatic tachycardia of POTS is exaggerated in the morning compared to the evening.”
From Postural tachycardia syndrome: beyond orthostatic intolerance (2015) · cites this paper as [18]
There is significant diurnal variability in POTS, with greater orthostatic tachycardia and a higher percentage of patients meeting heart rate criteria in the morning than in the afternoon or evening.
“there can be significant diurnal variability in POTS, with the degree of orthostatic tachycardia and percentage of patients meeting HR criteria being higher in the morning compared with the afternoon or evening”
From Postural tachycardia syndrome – Diagnosis, physiology, and prognosis (2018) · cites this paper as Brewster et al., 2012
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
The citation lists haven’t been fetched yet
References 30 · Cited by 56
- Authors
- Brewster, J. A., Garland, E. M., Biaggioni, I., Black, B. K., Ling, J. F., Shibao, C. A., Robertson, D., & Raj, S. R.
- Affiliations
- Vanderbilt University (US)
- Corresponding author
- Biaggioni, Italo
- Robertson, David
- Venue
- Clinical Science
- Publisher
- Portland Press Ltd.
- Published
- 2011-09-12
- Volume
- 122
- Issue
- 1
- Pages
- 25-31
- ISSN
- 0143-5221 (ISSN-L)
- 1470-8736
- PMC
- PMC3172399
- OpenAlex
- W2000961425
- Cited by
- 56
- References
- 30
- Citations by year
- 2026: 3 · 2025: 2 · 2024: 8 · 2023: 3 · 2022: 4 · 2021: 4 · 2020: 5 · 2019: 3 · 2018: 3 · 2017: 4 · 2016: 3 · 2015: 2 · 2014: 3 · 2013: 5 · 2012: 4
- FWCI
- 3.92
- Type
- journal article
- Language
- en
- Open access
- green
- www.ncbi.nlm.nih.gov
- Locations
- Clinical Science (publishedVersion)
- PubMed (publishedVersion)
- Europe PMC (PubMed Central) (acceptedVersion)
- PubMed Central (acceptedVersion)
- Funders
- National Heart, Lung, and Blood Institute (R01HL071784, P01HL056693, R01HL102387, P01 HL-56693)
- National Institute of Neurological Disorders and Stroke (R01NS055670)
- National Center for Research Resources (KL2RR024977, TL1RR024978, UL1RR024975, K23RR020783)
- Topics
- Health Sciences › Medicine › Surgery › Cardiovascular Syncope and Autonomic Disorders
- Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › Heart Rate Variability and Autonomic Control
- Health Sciences › Health Professions › Physical Therapy, Sports Therapy and Rehabilitation › Balance, Gait, and Falls Prevention
- Keywords
- postural orthostatic tachycardia syndrome, orthostatic tachycardia, diurnal variation, heart rate, blood pressure, supine-to-standing transition, circadian rhythm
- MeSH terms
- Adult, Blood Pressure, Circadian Rhythm, Epinephrine, Female, Heart Rate, Hemodynamics, Humans, Male, Norepinephrine, Posture, Tachycardia, Supine Position, Postural Orthostatic Tachycardia Syndrome
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
