Cerebral Oximetry in Syncope and Syndromes of Orthostatic Intolerance
Cerebral autoregulation is crucial for maintaining cerebral blood flow and perfusion. In recent years, the importance of cerebral oxygenation in syncope and orthostatic intolerance (OI) has received increased attention. Cerebral tissue oxygenation can be measured by using near-infrared spectroscopy...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2019-11-01
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| Series: | Frontiers in Cardiovascular Medicine |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fcvm.2019.00171/full |
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| author | Isabella Kharraziha Isabella Kharraziha Hannes Holm Hannes Holm Erasmus Bachus Fabrizio Ricci Fabrizio Ricci Fabrizio Ricci Richard Sutton Richard Sutton Artur Fedorowski Artur Fedorowski Viktor Hamrefors Viktor Hamrefors |
| author_facet | Isabella Kharraziha Isabella Kharraziha Hannes Holm Hannes Holm Erasmus Bachus Fabrizio Ricci Fabrizio Ricci Fabrizio Ricci Richard Sutton Richard Sutton Artur Fedorowski Artur Fedorowski Viktor Hamrefors Viktor Hamrefors |
| author_sort | Isabella Kharraziha |
| collection | DOAJ |
| description | Cerebral autoregulation is crucial for maintaining cerebral blood flow and perfusion. In recent years, the importance of cerebral oxygenation in syncope and orthostatic intolerance (OI) has received increased attention. Cerebral tissue oxygenation can be measured by using near-infrared spectroscopy (NIRS), which determines the ratio of oxygenated hemoglobin to total hemoglobin in cerebral tissue. NIRS is non-invasive technology using near-infrared light, which displays real-time cerebral tissue oxygenation. Normal values of cerebral tissue oxygenation in healthy subjects are 60 to 80%. Head-up tilt test (HUT) offers the opportunity to observe the haemodynamic changes precipitating syncope and is, today, the standard method for the evaluation of syncope and orthostatic intolerance syndromes. In previous studies where NIRS was applied during HUT, a significant decrease in cerebral tissue oxygenation both prior to and during loss-of-consciousness in vasovagal syncope (VVS) has been observed. Interestingly, cerebral tissue oxygenation appears to decrease even before haemodynamic changes can be observed. Apart from VVS, cerebral tissue oxygenation decreases during orthostatic provocation in patients with orthostatic hypotension (OH) and postural orthostatic tachycardia syndrome (POTS), in the latter even in the absence of hypotension. Importantly, decline of cerebral tissue oxygenation in VVS and POTS during HUT may not correlate with hemodynamic changes. In this mini review, we summarize the current knowledge of the application of cerebral oximetry in syncope and orthostatic intolerance syndromes, discuss its likely value as a clinical diagnostic tool and also emphasize its potential in the understanding of the relevant pathophysiology. |
| first_indexed | 2024-12-11T19:40:50Z |
| format | Article |
| id | doaj.art-626914a423ec4ceeb814d80e755b4d42 |
| institution | Directory Open Access Journal |
| issn | 2297-055X |
| language | English |
| last_indexed | 2024-12-11T19:40:50Z |
| publishDate | 2019-11-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Cardiovascular Medicine |
| spelling | doaj.art-626914a423ec4ceeb814d80e755b4d422022-12-22T00:53:02ZengFrontiers Media S.A.Frontiers in Cardiovascular Medicine2297-055X2019-11-01610.3389/fcvm.2019.00171494533Cerebral Oximetry in Syncope and Syndromes of Orthostatic IntoleranceIsabella Kharraziha0Isabella Kharraziha1Hannes Holm2Hannes Holm3Erasmus Bachus4Fabrizio Ricci5Fabrizio Ricci6Fabrizio Ricci7Richard Sutton8Richard Sutton9Artur Fedorowski10Artur Fedorowski11Viktor Hamrefors12Viktor Hamrefors13Department of Clinical Sciences, Lund University, Malmö, SwedenDepartment of Internal Medicine, Skåne University Hospital, Malmö, SwedenDepartment of Clinical Sciences, Lund University, Malmö, SwedenDepartment of Cardiology, Skåne University Hospital, Malmö, SwedenDepartment of Clinical Sciences, Lund University, Malmö, SwedenDepartment of Clinical Sciences, Lund University, Malmö, SwedenInstitute of Cardiology, University “G. d'Annunzio”, Chieti, ItalyDepartment of Neuroscience and Imaging, ITAB - Institute Advanced Biomedical Technologies, University “G. d'Annunzio”, Chieti, ItalyDepartment of Cardiology, Skåne University Hospital, Malmö, SwedenNational Heart and Lung Institute, Imperial College, Hammersmith Hospital, London, United KingdomDepartment of Clinical Sciences, Lund University, Malmö, SwedenDepartment of Cardiology, Skåne University Hospital, Malmö, SwedenDepartment of Clinical Sciences, Lund University, Malmö, SwedenDepartment of Internal Medicine, Skåne University Hospital, Malmö, SwedenCerebral autoregulation is crucial for maintaining cerebral blood flow and perfusion. In recent years, the importance of cerebral oxygenation in syncope and orthostatic intolerance (OI) has received increased attention. Cerebral tissue oxygenation can be measured by using near-infrared spectroscopy (NIRS), which determines the ratio of oxygenated hemoglobin to total hemoglobin in cerebral tissue. NIRS is non-invasive technology using near-infrared light, which displays real-time cerebral tissue oxygenation. Normal values of cerebral tissue oxygenation in healthy subjects are 60 to 80%. Head-up tilt test (HUT) offers the opportunity to observe the haemodynamic changes precipitating syncope and is, today, the standard method for the evaluation of syncope and orthostatic intolerance syndromes. In previous studies where NIRS was applied during HUT, a significant decrease in cerebral tissue oxygenation both prior to and during loss-of-consciousness in vasovagal syncope (VVS) has been observed. Interestingly, cerebral tissue oxygenation appears to decrease even before haemodynamic changes can be observed. Apart from VVS, cerebral tissue oxygenation decreases during orthostatic provocation in patients with orthostatic hypotension (OH) and postural orthostatic tachycardia syndrome (POTS), in the latter even in the absence of hypotension. Importantly, decline of cerebral tissue oxygenation in VVS and POTS during HUT may not correlate with hemodynamic changes. In this mini review, we summarize the current knowledge of the application of cerebral oximetry in syncope and orthostatic intolerance syndromes, discuss its likely value as a clinical diagnostic tool and also emphasize its potential in the understanding of the relevant pathophysiology.https://www.frontiersin.org/article/10.3389/fcvm.2019.00171/fullsyncopevasovagal syncopecerebral oxygenationhemodynamicspostural orthostatic tachycardia syndromehead-up tilt |
| spellingShingle | Isabella Kharraziha Isabella Kharraziha Hannes Holm Hannes Holm Erasmus Bachus Fabrizio Ricci Fabrizio Ricci Fabrizio Ricci Richard Sutton Richard Sutton Artur Fedorowski Artur Fedorowski Viktor Hamrefors Viktor Hamrefors Cerebral Oximetry in Syncope and Syndromes of Orthostatic Intolerance Frontiers in Cardiovascular Medicine syncope vasovagal syncope cerebral oxygenation hemodynamics postural orthostatic tachycardia syndrome head-up tilt |
| title | Cerebral Oximetry in Syncope and Syndromes of Orthostatic Intolerance |
| title_full | Cerebral Oximetry in Syncope and Syndromes of Orthostatic Intolerance |
| title_fullStr | Cerebral Oximetry in Syncope and Syndromes of Orthostatic Intolerance |
| title_full_unstemmed | Cerebral Oximetry in Syncope and Syndromes of Orthostatic Intolerance |
| title_short | Cerebral Oximetry in Syncope and Syndromes of Orthostatic Intolerance |
| title_sort | cerebral oximetry in syncope and syndromes of orthostatic intolerance |
| topic | syncope vasovagal syncope cerebral oxygenation hemodynamics postural orthostatic tachycardia syndrome head-up tilt |
| url | https://www.frontiersin.org/article/10.3389/fcvm.2019.00171/full |
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