ArticleAmerican journal of physiology. Heart and circulatory physiology2009
Increased phase synchronization and decreased cerebral autoregulation during fainting in the young.
Article in American journal of physiology. Heart and circulatory physiology, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 25 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
25 citing papers in PubMed, 42 citations in OpenAlex.
- Dynamic cerebral autoregulation is acutely impaired during maximal apnoea in trained divers.PloS one · 2014Trial
- Cardiovascular disease and depression: a bidirectional relationship and its clinical implications.Frontiers in psychiatry · 2025Review
- Phenylephrine alters phase synchronization between cerebral blood velocity and blood pressure in ME/CFS with orthostatic intolerance.American journal of physiology. Regulatory, integrative and comparative physiology · 2024Article
- Characteristics of corticomuscular coupling during wheelchair Tai Chi in patients with spinal cord injury.Journal of neuroengineering and rehabilitation · 2023Article
- On the Different Abilities of Cross-Sample Entropy and K-Nearest-Neighbor Cross-Unpredictability in Assessing Dynamic Cardiorespiratory and Cerebrovascular Interactions.Entropy (Basel, Switzerland) · 2023Article
- Increased respiratory modulation of cardiovascular control reflects improved blood pressure regulation in pregnancy.Frontiers in physiology · 2023Article
- Right-to-left shunts in unexplained syncope: an age- and sex-matched case-control study.Quantitative imaging in medicine and surgery · 2022Article
- When Sinus Tachycardia Becomes Too Much: Negative Effects of Excessive Upright Tachycardia on Cardiac Output in Vasovagal Syncope, Postural Tachycardia Syndrome, and Inappropriate Sinus Tachycardia.Circulation. Arrhythmia and electrophysiology · 2020Article
- Wavelet decomposition analysis is a clinically relevant strategy to evaluate cerebrovascular buffering of blood pressure after spinal cord injury.American journal of physiology. Heart and circulatory physiology · 2018Article
- Indexes of cerebral autoregulation do not reflect impairment in syncope: insights from head-up tilt test of vasovagal and autonomic failure subjects.European journal of applied physiology · 2017Article
- Mechanisms of Vasovagal Syncope in the Young: Reduced Systemic Vascular Resistance Versus Reduced Cardiac Output.Journal of the American Heart Association · 2017Article
- Applying time-frequency analysis to assess cerebral autoregulation during hypercapnia.PloS one · 2017Article
- Physical Activity Level and Symptom Duration Are Not Associated After Concussion.The American journal of sports medicine · 2016Article
- Cerebrovascular effects of the thigh cuff maneuver.American journal of physiology. Heart and circulatory physiology · 2015Article
- Review
- Blunted cerebral blood flow velocity in response to a nitric oxide donor in postural tachycardia syndrome.American journal of physiology. Heart and circulatory physiology · 2014Article
- Time-varying modeling of cerebral hemodynamics.IEEE transactions on bio-medical engineering · 2014Article
- Disruption of phase synchronization between blood pressure and muscle sympathetic nerve activity in postural vasovagal syncope.American journal of physiology. Heart and circulatory physiology · 2013Article
- Common syndromes of orthostatic intolerance.Pediatrics · 2013Review
- Mechanisms of sympathetic regulation in orthostatic intolerance.Journal of applied physiology (Bethesda, Md. : 1985) · 2012Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors at 2 institutions in 1 country.
Funding
Abstract
Vasovagal syncope may be due to a transient cerebral hypoperfusion that accompanies frequency entrainment between arterial pressure (AP) and cerebral blood flow velocity (CBFV). We hypothesized that cerebral autoregulation fails during fainting; a phase synchronization index (PhSI) between AP and CBFV was used as a nonlinear, nonstationary, time-dependent measurement of cerebral autoregulation. Twelve healthy control subjects and twelve subjects with a history of vasovagal syncope underwent 10-min tilt table testing with the continuous measurement of AP, CBFV, heart rate (HR), end-tidal CO2 (ETCO2), and respiratory frequency. Time intervals were defined to compare physiologically equivalent periods in fainters and control subjects. A PhSI value of 0 corresponds to an absence of phase synchronization and efficient cerebral autoregulation, whereas a PhSI value of 1 corresponds to complete phase synchronization and inefficient cerebral autoregulation. During supine baseline conditions, both control and syncope groups demonstrated similar oscillatory changes in phase, with mean PhSI values of 0.58+/-0.04 and 0.54+/-0.02, respectively. Throughout tilt, control subjects demonstrated similar PhSI values compared with supine conditions. Approximately 2 min before fainting, syncopal subjects demonstrated a sharp decrease in PhSI (0.23+/-0.06), representing efficient cerebral autoregulation. Immediately after this period, PhSI increased sharply, suggesting inefficient cerebral autoregulation, and remained elevated at the time of faint (0.92+/-0.02) and during the early recovery period (0.79+/-0.04) immediately after the return to the supine position. Our data demonstrate rapid, biphasic changes in cerebral autoregulation, which are temporally related to vasovagal syncope. Thus, a sudden period of highly efficient cerebral autoregulation precedes the virtual loss of autoregulation, which continued during and after the faint.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.