ArticleAmerican journal of physiology. Heart and circulatory physiology2011
Respiration drives phase synchronization between blood pressure and RR interval following loss of cardiovagal baroreflex during vasovagal syncope.
Article in American journal of physiology. Heart and circulatory physiology, 2011. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 22 papers.
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Who cites it
22 citing papers in PubMed, 53 citations in OpenAlex.
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- 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
- Increased respiratory modulation of cardiovascular control reflects improved blood pressure regulation in pregnancy.Frontiers in physiology · 2023Article
- A study on the immediate effects of enhanced external counterpulsation on physiological coupling.Frontiers in neuroscience · 2023Article
- Classification of orthostatic intolerance through data analytics.Medical & biological engineering & computing · 2021Article
- Pathophysiology and Individualized Management of Vasovagal Syncope and Postural Tachycardia Syndrome in Children and Adolescents: An Update.Neuroscience bulletin · 2020Review
- 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
- Vestibular, locomotor, and vestibulo-autonomic research: 50 years of collaboration with Bernard Cohen.Journal of neurophysiology · 2020Review
- Activation of Functional Brain Networks in Children With Psychogenic Non-epileptic Seizures.Frontiers in human neuroscience · 2020Article
- Time-Frequency Analysis of Cardiovascular and Cardiorespiratory Interactions During Orthostatic Stress by Extended Partial Directed Coherence.Entropy (Basel, Switzerland) · 2019Article
- The pathophysiology of the vasovagal response.Heart rhythm · 2018Review
- Mechanisms of Vasovagal Syncope in the Young: Reduced Systemic Vascular Resistance Versus Reduced Cardiac Output.Journal of the American Heart Association · 2017Article
- A Model of Blood Pressure, Heart Rate, and Vaso-Vagal Responses Produced by Vestibulo-Sympathetic Activation.Frontiers in neuroscience · 2016Article
- Cardiovascular and cardiorespiratory phase synchronization in normovolemic and hypovolemic humans.European journal of applied physiology · 2015Article
- Altered oscillatory cerebral blood flow velocity and autoregulation in postural tachycardia syndrome.Frontiers in physiology · 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
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Authors and funding
4 authors at 2 institutions in 1 country.
Funding
Abstract
Loss of the cardiovagal baroreflex (CVB), thoracic hypovolemia, and hyperpnea contribute to the nonlinear time-dependent hemodynamic instability of vasovagal syncope. We used a nonlinear phase synchronization index (PhSI) to describe the extent of coupling between cardiorespiratory parameters, systolic blood pressure (SBP) or arterial pressure (AP), RR interval (RR), and ventilation, and a directional index (DI) measuring the direction of coupling. We also examined phase differences directly. We hypothesized that AP-RR interval PhSI would be normal during early upright tilt, indicating intact CVB, but would progressively decrease as faint approached and CVB failed. Continuous measurements of AP, RR interval, respiratory plethysomography, and end-tidal CO2 were recorded supine and during 70-degree head-up tilt in 15 control subjects and 15 fainters. Data were evaluated during five distinct times: baseline, early tilt, late tilt, faint, and recovery. During late tilt to faint, fainters exhibited a biphasic change in SBP-RR interval PhSI. Initially in fainters during late tilt, SBP-RR interval PhSI decreased (fainters, from 0.65±0.04 to 0.24±0.03 vs. control subjects, from 0.51±0.03 to 0.48±0.03; P<0.01) but then increased at the time of faint (fainters=0.80±0.03 vs. control subjects=0.42±0.04; P<0.001) coinciding with a change in phase difference from positive to negative. Starting in late tilt and continuing through faint, fainters exhibited increasing phase coupling between respiration and AP PhSI (fainters=0.54±0.06 vs. control subjects=0.27±0.03; P<0.001) and between respiration and RR interval (fainters=0.54±0.05 vs. control subjects=0.37±0.04; P<0.01). DI indicated respiratory driven AP (fainters=0.84±0.04 vs. control subjects=0.39±0.09; P<0.01) and RR interval (fainters=0.73±0.10 vs. control subjects=0.23±0.11; P<0.001) in fainters. The initial drop in the SBP-RR interval PhSI and directional change of phase difference at late tilt indicates loss of cardiovagal baroreflex. The subsequent increase in SBP-RR interval PhSI is due to a respiratory synchronization and drive on both AP and RR interval. Cardiovagal baroreflex is lost before syncope and supplanted by respiratory reflexes, producing hypotension and bradycardia.
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