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Medow MS, Stewart JM. Phenylephrine alters phase synchronization between cerebral blood velocity and blood pressure in ME/CFS with orthostatic intolerance. Am J Physiol Regul Integr Comp Physiol 2024; 326:R599-R608. [PMID: 38682242 PMCID: PMC11381003 DOI: 10.1152/ajpregu.00071.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 04/16/2024] [Accepted: 04/19/2024] [Indexed: 05/01/2024]
Abstract
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) with orthostatic intolerance (OI) is characterized by neurocognitive deficits perhaps related to upright hypocapnia and loss of cerebral autoregulation (CA). We performed N-back neurocognition testing and calculated the phase synchronization index (PhSI) between arterial pressure (AP) and cerebral blood velocity (CBV) as a time-dependent measurement of cerebral autoregulation in 11 control (mean age = 24.1 yr) and 15 patients with ME/CFS (mean age = 21.8 yr). All patients with ME/CFS had postural tachycardia syndrome (POTS). A 10-min 60° head-up tilt (HUT) significantly increased heart rate (109.4 ± 3.9 vs. 77.2 ± 1.6 beats/min, P < 0.05) and respiratory rate (20.9 ± 1.7 vs. 14.2 ± 1.2 breaths/min, P < 0.05) and decreased end-tidal CO2 (ETCO2; 33.9 ± 1.1 vs. 42.8 ± 1.2 Torr, P < 0.05) in ME/CFS versus control. In ME/CFS, HUT significantly decreased CBV compared with control (-22.5% vs. -8.7%, P < 0.005). To mitigate the orthostatic CBV reduction, we administered supplemental CO2, phenylephrine, and acetazolamide and performed N-back testing supine and during HUT. Only phenylephrine corrected the orthostatic decrease in neurocognition by reverting % correct n = 4 N-back during HUT in ME/CFS similar to control (ME/CFS = 38.5 ± 5.5 vs. ME/CFS + PE= 65.6 ± 5.7 vs. Control 56.9 ± 7.5). HUT in ME/CFS resulted in increased PhSI values indicating decreased CA. Although CO2 and acetazolamide had no effect on PhSI in ME/CFS, phenylephrine caused a significant reduction in PhSI (ME/CFS = 0.80 ± 0.03 vs. ME/CFS + PE= 0.69 ± 0.04, P < 0.05) and improved cerebral autoregulation. Thus, PE improved neurocognitive function in patients with ME/CFS, perhaps related to improved neurovascular coupling, cerebral autoregulation, and maintenance of CBV.NEW & NOTEWORTHY We evaluated cognitive function before and after CO2, acetazolamide, and phenylephrine, which mitigate orthostatic reductions in cerebral blood velocity. Neither CO2 nor acetazolamide affected N-back testing (% correct answers) during an orthostatic challenge. Only phenylephrine improved upright N-back performance in ME/CFS, as it both blocked hyperventilation and increased CO2 significantly compared with those untreated. And only phenylephrine resulted in improved PSI values in both ME/CFS and control while upright, suggesting improved cerebral autoregulation.
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Affiliation(s)
- Marvin S Medow
- Department of Pediatrics, New York Medical College, Valhalla, New York, United States
- Department of Physiology, New York Medical College, Valhalla, New York, United States
| | - Julian M Stewart
- Department of Pediatrics, New York Medical College, Valhalla, New York, United States
- Department of Physiology, New York Medical College, Valhalla, New York, United States
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Meglič B, Danieli A. Glyceryl trinitrate-induced blood pressure variability decrease during head-up tilt test predicts vasovagal response. Blood Press Monit 2023; 28:236-243. [PMID: 37334541 DOI: 10.1097/mbp.0000000000000653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
PURPOSE Glyceryl trinitrate (GTN) provoked cardioinhibitory syncope during the head-up tilt test is preceded by a period of disrupted blood pressure variability (BPV). Endogenous nitric oxide (NO) attenuates BPV independently of blood pressure (BP). We hypothesized that exogenous NO donor GTN might decrease BPV during the presyncope period. A decrease in BPV may predict the tilt outcome. METHODS We analyzed 29 tilt test recordings of subjects with GTN-induced cardioinhibitory syncope and 30 recordings of negative subjects. A recursive autoregressive model of BPV after GTN was performed; powers of the respiratory (0.15-0.45 Hz) and nonrespiratory frequency (0.01-0.15 Hz) bands were calculated for each of the 20 normalized time periods. The post-GTN relative changes in heart rate, BP, and BPV were calculated. RESULTS In the syncope group, spectral power of nonrespiratory frequency systolic and diastolic BPV progressively felt for 30% after GTN application and stabilized after 180 s. BP started to fall 240 s after the GTN application. Decrease in nonrespiratory frequency power of diastolic BPV 20 s after GTN administration predicted cardioinhibitory syncope (area under the curve 0.811; 77% sensitivity; 70% specificity; cutoff value > 7%). CONCLUSION GTN application during the tilt test attenuates systolic and diastolic nonrespiratory frequency BPV during the presyncope period, independent of BP. A decrease in nonrespiratory frequency diastolic BPV 20 s after GTN application predicts cardioinhibitory syncope with good sensitivity and moderate specificity.
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Affiliation(s)
- Bernard Meglič
- Department of Neurology, University Medical Center Ljubljana, Ljubljana, Slovenia
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Longo S, Legramante JM, Rizza S, Federici M. Vasovagal syncope: An overview of pathophysiological mechanisms. Eur J Intern Med 2023; 112:6-14. [PMID: 37030995 DOI: 10.1016/j.ejim.2023.03.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 03/09/2023] [Accepted: 03/23/2023] [Indexed: 04/10/2023]
Abstract
Syncope is a short-term transient loss of consciousness, characterized by rapid onset and complete spontaneous recovery. According to the 2018 European Society of Cardiology guidelines, three different types of syncope have been identified. However, all forms of syncope share a common final pathophysiological event, global cerebral hypoperfusion, which results from the inability of the circulatory system to maintain blood pressure at the level required to efficiently supply blood to the brain. The vasovagal syncope (VVS) is the most common form of syncope. Although, VVS is generally harmless, its frequent occurrence can negatively affect quality of life and increase the risk of adverse events. The pathophysiological mechanisms underlying VVS remain obscure. The multifaceted nature of VVS presents a veritable challenge to understanding this condition and developing preventative strategies. Thus, the aim of this review was to discuss the factors contributing to the pathogenesis of VVS and provide guidance for future research.
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Affiliation(s)
- Susanna Longo
- Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, Rome 00133 ITALY
| | - Jacopo M Legramante
- Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, Rome 00133 ITALY
| | - Stefano Rizza
- Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, Rome 00133 ITALY
| | - Massimo Federici
- Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, Rome 00133 ITALY.
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Miranda CM, da Silva RMFL, Peruhybe-Magalhães V, Brugada J. Vasoactive Biomarkers in Patients With Vasovagal Syncope During Head-Up Tilt Test: A Case-Control Study. CLINICAL MEDICINE INSIGHTS-CARDIOLOGY 2022; 16:11795468221116848. [PMID: 36046183 PMCID: PMC9421056 DOI: 10.1177/11795468221116848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 06/15/2022] [Indexed: 11/25/2022]
Abstract
Background: Vasovagal syncope (VVS) is the most common cause of syncope. Some stages of its pathophysiological mechanisms remain unclear. Vasoactive substances such as nitric oxide metabolites (NOx) and endothelin (ET) may be involved during acute orthostatic stress. Objective: To analyze plasma changes in NOx and ET and heart rate variability (HRV) in the supine positions (T1) and during the head-up tilt test (HUTT) (T2), in patients with VVS (case group) and control group. Methods: Thirty-seven patients (17 in the case group and 20 in the control group), matched for age and sex (mean aged 31.8 years) underwent HUTT with simultaneous HRV recording and venipuncture. Blood samples were collected during phases T1 and T2 and the analysis was performed without knowledge of the HUTT result. Results: In the total sample, there was an increase in NOx values (P = .014), however there was no increase in ET values from phase T1 to phase T2. Patients with VVS tended to increase plasma NOx values (P = .057) and had significantly higher plasma values compared to ET (P = .033) between phases T1 to T2. In the control group, there was no significant change in the values of these vasoactive substances. Regarding HRV, there were a decrease in the component HF (high frequency) and increased of the LF (low frequency)/HF ratio during HUTT. Conclusions: There was an increase in ET during HUTT occurred only in the case group. These patients are more likely to have an imbalance between antagonistic vasoactive biomarkers during orthostatic stress.
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Affiliation(s)
- Cláudia Madeira Miranda
- Faculty of Medicine, Federal University of Minas Gerais, Brazil.,Madre Teresa Hospital, Minas Gerais, Brazil
| | | | | | - Josep Brugada
- Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
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Zandstra TE, Notenboom RGE, Wink J, Kiès P, Vliegen HW, Egorova AD, Schalij MJ, De Ruiter MC, Jongbloed MRM. Asymmetry and Heterogeneity: Part and Parcel in Cardiac Autonomic Innervation and Function. Front Physiol 2021; 12:665298. [PMID: 34603069 PMCID: PMC8481575 DOI: 10.3389/fphys.2021.665298] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 08/26/2021] [Indexed: 11/17/2022] Open
Abstract
The cardiac autonomic nervous system (cANS) regulates cardiac adaptation to different demands. The heart is an asymmetrical organ, and in the selection of adequate treatment of cardiac diseases it may be relevant to take into account that the cANS also has sidedness as well as regional differences in anatomical, functional, and molecular characteristics. The left and right ventricles respond differently to adrenergic stimulation. Isoforms of nitric oxide synthase, which plays an important role in parasympathetic function, are also distributed asymmetrically across the heart. Treatment of cardiac disease heavily relies on affecting left-sided heart targets which are thought to apply to the right ventricle as well. Functional studies of the right ventricle have often been neglected. In addition, many principles have only been investigated in animals and not in humans. Anatomical and functional heterogeneity of the cANS in human tissue or subjects is highly valuable for understanding left- and right-sided cardiac pathology and for identifying novel treatment targets and modalities. Within this perspective, we aim to provide an overview and synthesis of anatomical and functional heterogeneity of the cANS in tissue or subjects, focusing on the human heart.
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Affiliation(s)
- Tjitske E. Zandstra
- Department of Cardiology, Leiden University Medical Center, Leiden, Netherlands
| | | | - Jeroen Wink
- Department of Anesthesiology, Leiden University Medical Center, Leiden, Netherlands
| | - Philippine Kiès
- Department of Cardiology, Leiden University Medical Center, Leiden, Netherlands
| | - Hubert W. Vliegen
- Department of Cardiology, Leiden University Medical Center, Leiden, Netherlands
| | | | - Martin J. Schalij
- Department of Cardiology, Leiden University Medical Center, Leiden, Netherlands
| | - Marco C. De Ruiter
- Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, Netherlands
| | - Monique R. M. Jongbloed
- Department of Cardiology, Leiden University Medical Center, Leiden, Netherlands
- Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, Netherlands
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Medow MS, Guber K, Chokshi S, Terilli C, Visintainer P, Stewart JM. The Benefits of Oral Rehydration on Orthostatic Intolerance in Children with Postural Tachycardia Syndrome. J Pediatr 2019; 214:96-102. [PMID: 31405524 PMCID: PMC6815702 DOI: 10.1016/j.jpeds.2019.07.041] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/11/2019] [Accepted: 07/15/2019] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To evaluate whether equal volumes of oral rehydration solution (ORS) or intravenous (IV) saline provide similar improvements in cardiovascular status during controlled orthostatic challenge when administered to subjects with postural tachycardia syndrome (POTS) with orthostatic intolerance. STUDY DESIGN We studied the neurovascular response to fluid loading during orthostatic stress using lower body negative pressure (LBNP) in 10 subjects with POTS with orthostatic intolerance and 15 controls, and on subsequent days before and 1 hour after IV saline infusion or ingestion of ORS. RESULTS Subjects with POTS exhibited reduced tolerance to LBNP (P < .0001) compared with controls (Orthostatic Index of 35 715 ± 3469 vs 93 980 ± 7977, respectively). In POTS, following ORS but not saline infusion, cerebral blood flow velocity (CBFv) was significantly higher than that with no treatment, at -45 mm Hg (P < .0005). Although fluid loading did not confer any advantage in controls, subjects with POTS experienced a significant improvement in orthostatic tolerance following both saline infusion (100 ± 9.7 vs 134.5 ± 17.4; P < .05) and ORS (100 ± 9.7 vs 155.6 ± 15.7; P < .001) when evaluated by normalized orthostatic index (P < .001, compared with untreated baseline). CONCLUSIONS Maintenance of CBFv may have resulted in the improved short-term orthostatic tolerance exhibited by the subjects with POTS following ORS administration. ORS is a convenient, safe, and effective therapy for short-term relief of orthostatic intolerance.
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Affiliation(s)
- Marvin S Medow
- Department of Pediatrics, New York Medical College, Valhalla, NY; Department of Physiology, New York Medical College, Valhalla, NY.
| | | | | | - Courtney Terilli
- Department of Pediatrics, New York Medical College, Valhalla, NY
| | - Paul Visintainer
- Department of Epidemiology and Biostatistics, Baystate Medical Center, University of Massachusetts School of Medicine, Worcester, MA
| | - Julian M Stewart
- Department of Pediatrics, New York Medical College, Valhalla, NY; Department of Physiology, New York Medical College, Valhalla, NY
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Atıcı A, Aciksari G, Baycan OF, Barman HA, Sonsöz MR, Sahin M, Asoglu R, Demirkıran A, Kul Ş, Gungor B, Durmaz E, Bilge AK, Sahin I. Serum Asymmetric Dimethylarginine Levels in Patients with Vasovagal Syncope. ACTA ACUST UNITED AC 2019; 55:medicina55110718. [PMID: 31671882 PMCID: PMC6915676 DOI: 10.3390/medicina55110718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/09/2019] [Accepted: 10/10/2019] [Indexed: 11/23/2022]
Abstract
Background and Objectives: Vasovagal syncope (VVS) is the most common cause of syncope and has multiple pathophysiological mechanisms. Asymmetric dimethylarginine (ADMA) is the major inhibitor of nitric oxide (NO). In this study, we aimed to investigate the relationship between plasma ADMA levels and syncope during the head-up tilt (HUT) test. Materials and Methods: Overall, 97 patients were included in this study. They were above 18 years of age and were admitted to our clinic with the complaint of at least one episode of syncope consistent with VVS. The HUT test was performed in all patients. Patients were divided into the following two groups based on the HUT test results: group 1 included 57 patients with a positive HUT test and group 2 included 35 patients with a negative HUT test. Blood samples were taken before and immediately after the HUT test to measure ADMA levels. Results: No significant intergroup differences were observed concerning gender and age (female gender 68% vs 60%; mean age 24.85 ± 4.01 vs 25.62 ± 3.54 years, respectively, for groups 1 and 2). ADMA values were similar between groups 1 and 2 before the HUT test [ADMA of 958 (544–1418) vs 951 (519–1269); p = 0.794]. In the negative HUT group, no significant differences were observed in ADMA levels before and after the HUT test [ADMA of 951 (519–1269) vs 951 (519–1566); p = 0.764]. However, in the positive HUT group, ADMA levels were significantly decreased following the HUT test [pretest ADMA of 958 (544–1418) vs post-test ADMA of 115 (67–198); p < 0.001]. Conclusion: ADMA levels significantly decreased after the HUT test in patients with VVS.
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Affiliation(s)
- Adem Atıcı
- Cardiology Department, Istanbul Medeniyet University, Goztepe Training and Research Hospital, 34722 Istanbul, Turkey.
| | - Gonul Aciksari
- Cardiology Department, Istanbul Medeniyet University, Goztepe Training and Research Hospital, 34722 Istanbul, Turkey.
| | - Omer Faruk Baycan
- Cardiology Department, Istanbul Medeniyet University, Goztepe Training and Research Hospital, 34722 Istanbul, Turkey.
| | - Hasan Ali Barman
- Cardiology Department, Okmeydani Training and Research Hospital, 34384 Istanbul, Turkey.
| | - Mehmet Rasih Sonsöz
- Cardiology Department, Istanbul University Istanbul School of Medicine, 34093 Istanbul, Turkey.
| | - Mustafa Sahin
- Biochemistry Department, Hitit University, Erol Olcok Training and Research Hospital, 19040 Corum, Turkey.
| | - Ramazan Asoglu
- Cardiology Department, Adiyaman Training and Research Hospital, 02200 Adiyaman, Turkey.
| | - Ahmet Demirkıran
- Cardiology Department, Istanbul University Istanbul School of Medicine, 34093 Istanbul, Turkey.
| | - Şeref Kul
- Cardiology Department, Istanbul Medeniyet University, Goztepe Training and Research Hospital, 34722 Istanbul, Turkey.
| | - Baris Gungor
- Department of Cardiology, Siyami Ersek Cardiothoracic Surgery Center, 34668 Istanbul, Turkey.
| | - Eser Durmaz
- Cardiology Department, Istanbul University-Cerrahpasa, Cerrahpasa School of Medicine, 34096 Istanbul, Turkey.
| | - Ahmet Kaya Bilge
- Cardiology Department, Istanbul University Istanbul School of Medicine, 34093 Istanbul, Turkey.
| | - Irfan Sahin
- Cardiology Department, Bagcilar Training ve Research Hospital, Bagcilar Center, 34100 Istanbul, Turkey.
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Stewart JM, Shaban MA, Fialkoff T, Tuma‐Marcella B, Visintainer P, Terilli C, Medow MS. Mechanisms of tilt-induced vasovagal syncope in healthy volunteers and postural tachycardia syndrome patients without past history of syncope. Physiol Rep 2019; 7:e14148. [PMID: 31250563 PMCID: PMC6597794 DOI: 10.14814/phy2.14148] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 05/31/2019] [Indexed: 12/25/2022] Open
Abstract
Upright tilt table testing has been used to test for vasovagal syncope (VVS) but can result in "false positives" in which tilt-induced fainting (tilt+) occurs in the absence of real-world fainting. Tilt+ occurs in healthy volunteers and in patients with postural tachycardia syndrome (POTS) and show enhanced susceptibility to orthostatic hypotension. We hypothesized that the mechanisms for hypotensive susceptibility differs between tilt+ healthy volunteers (Control-Faint (N = 12)), tilt+ POTS patients (POTS-Faint (N = 12)) and a non-fainter control group of (Control-noFaint) (N = 10). Subjects were studied supine and during 70° upright tilt while blood pressure (BP), cardiac output (CO), and systemic vascular resistance (SVR), were measured continuously. Impedance plethysmography estimated regional blood volumes, flows, and vascular resistance. Heart rate was increased while central blood volume was decreased in both Faint groups. CO increased in Control-Faint because of reduced splanchnic vascular resistance; splanchnic pooling was similar to Control-noFaint. Splanchnic blood flow in POTS-Faint decreased and resistance increased similar to Control-noFaint but splanchnic blood volume was markedly increased. Decreased SVR and splanchnic arterial vasoconstriction is the mechanism for faint in Control-Faint. Decreased CO caused by enhanced splanchnic pooling is the mechanism for faint in POTS-Faint. We propose that intrahepatic resistance is increased in POTS-Faint resulting in pooling and that both intrahepatic resistance and splanchnic arterial vasoconstriction are reduced in Control-Faint resulting in increased splanchnic blood flow and reduced splanchnic resistance.
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Affiliation(s)
- Julian M. Stewart
- Departments of Pediatrics and PhysiologyNew York Medical CollegeValhallaNew York
| | - Mohamed A. Shaban
- Departments of Pediatrics and PhysiologyNew York Medical CollegeValhallaNew York
| | - Tyler Fialkoff
- Departments of Pediatrics and PhysiologyNew York Medical CollegeValhallaNew York
| | | | - Paul Visintainer
- Baystate Medical CenterUniversity of Massachusetts School of MedicineSpringfield 01199Massachusetts
| | - Courtney Terilli
- Departments of Pediatrics and PhysiologyNew York Medical CollegeValhallaNew York
| | - Marvin S. Medow
- Departments of Pediatrics and PhysiologyNew York Medical CollegeValhallaNew York
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9
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Autonomic uprising: the tilt table test in autonomic medicine. Clin Auton Res 2019; 29:215-230. [DOI: 10.1007/s10286-019-00598-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 02/21/2019] [Indexed: 12/18/2022]
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10
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Bai W, Chen S, Tang CS, Qi JG, Cui QH, Xu M, Du JB, Jin HF. Gut microbiota analysis and its significance in vasovagal syncope in children. Chin Med J (Engl) 2019; 132:411-419. [PMID: 30707176 PMCID: PMC6595724 DOI: 10.1097/cm9.0000000000000086] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Vasovagal syncope (VVS) is common in children and greatly affect both physical and mental health. But the mechanisms have not been completely explained. This study was designed to analyze the gut microbiota in children with VVS and explore its clinical significance. METHODS Fecal samples from 20 VVS children and 20 matched controls were collected, and the microbiota were analyzed by 16S rRNA gene sequencing. The diversity and microbiota compositions of the VVS cases and controls were compared with the independent sample t test or Mann-Whitney U test. The correlation between the predominant bacteria and clinical symptoms was analyzed using Pearson or Spearman correlation test. RESULTS No significant differences in diversity were evident between VVS and controls (P > 0.05). At the family level, the relative abundance of Ruminococcaceae was significantly higher in VVS children than in controls (median [Q1, Q3]: 22.10% [16.89%, 27.36%] vs. 13.92% [10.31%, 20.18%], Z = -2.40, P < 0.05), and LEfSe analysis revealed Ruminococcaceae as a discriminative feature (linear discriminant analysis [LDA] score > 4, P < 0.05). The relative abundance of Ruminococcaceae in VVS patients was positively correlated with the frequency of syncope (r = 0.616, P < 0.01). In terms of its correlation with hemodynamics, we showed that relative abundance of Ruminococcaceae was negatively correlated with the systolic and diastolic pressure reduction at the positive response in head-up tilt test (HUTT; r = -0.489 and -0.448, all P < 0.05), but was positively correlated with the mean pressure drop and decline rate (r = 0.489 and 0.467, all P < 0.05) as well as diastolic pressure drop and decline rate at the HUTT positive response (r = 0.579 and 0.589, all P < 0.01) in VVS patients. CONCLUSION Ruminococcaceae was the predominant gut bacteria and was associated with the clinical symptoms and hemodynamics of VVS, suggesting that gut microbiota might be involved in the development of VVS.
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Affiliation(s)
- Wei Bai
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Selena Chen
- Department of Biochemistry and Cellular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Chao-Shu Tang
- Department of Physiology and Pathophysiology, Peking University Health Sciences Centre, Beijing 100191, China
- Key Laboratory of Molecular Cardiovascular Sciences, The Ministry of Education, Beijing 100191, China
| | - Jian-Guang Qi
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Qing-Hua Cui
- Department of Biomedical Informatics, Peking University Health Sciences Centre, Beijing 100191, China
| | - Ming Xu
- Institute of Vascular Research, Peking University Third Hospital, Beijing 100191, China
| | - Jun-Bao Du
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Hong-Fang Jin
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
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Márquez MF, Allende R, Márquez-Velasco R, Hermosillo AG. Role of nitric oxide in vasovagal syncope. A puzzle solved but there could be another piece. BRITISH HEART JOURNAL 2018; 104:786. [DOI: 10.1136/heartjnl-2017-312820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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12
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Jardine DL, Wieling W, Brignole M, Lenders JWM, Sutton R, Stewart J. The pathophysiology of the vasovagal response. Heart Rhythm 2017; 15:921-929. [PMID: 29246828 DOI: 10.1016/j.hrthm.2017.12.013] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Indexed: 10/18/2022]
Abstract
In part I of this study, we found that the classical studies on vasovagal syncope, conducted in fit young subjects, overstated vasodilatation as the dominant hypotensive mechanism. Since 1980, blood pressure and cardiac output have been measured continuously using noninvasive methods during tilt, mainly in patients with recurrent syncope, including women and the elderly. This has allowed us to analyze in more detail the complex sequence of hemodynamic changes leading up to syncope in the laboratory. All tilt-sensitive patients appear to progress through 4 phases: (1) early stabilization, (2) circulatory instability, (3) terminal hypotension, and (4) recovery. The physiology responsible for each phase is discussed. Although the order of phases is consistent, the time spent in each phase may vary. In teenagers and young adults, progressive hypotension during phases 2 and 3 can be driven by vasodilatation or falling cardiac output. The fall in cardiac output is secondary to a progressive decrease in stroke volume because blood is pooled in the splanchnic veins. In adults a fall in cardiac output is the dominant hypotensive mechanism because systemic vascular resistance always remains above baseline levels.
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Affiliation(s)
- David L Jardine
- Department of General Medicine, Christchurch Hospital, University of Otago, Christchurch, New Zealand.
| | - Wouter Wieling
- Department of Internal Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Michele Brignole
- Department of Cardiology, Arrhythmologic Centre, Ospedali del Tigullio, Lavagna, Italy
| | - Jacques W M Lenders
- Department of Internal Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands; Department of Internal Medicine III, Technical University Dresden, Dresden, Germany
| | - Richard Sutton
- National Heart and Lung institute, Imperial College, London, United Kingdom
| | - Julian Stewart
- Departments of Pediatrics, Physiology, and Medicine, New York Medical College, Valhalla, New York
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