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Redondo J, Conte LM, Seda G. Vasovagal Electrophysiology on 12-Lead ECG After Venipuncture. Mil Med 2023; 188:3680-3682. [PMID: 35762141 DOI: 10.1093/milmed/usac178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/30/2022] [Accepted: 06/04/2022] [Indexed: 11/14/2022] Open
Abstract
Vasovagal syncope is the most common form of syncope seen in young and otherwise healthy active duty service members. Although self-limiting, syncopal events often produce a significant drain of medical resources because of their sudden and often dramatic presentation, which can be associated with traumatic injuries secondary to loss in postural tone. Malignant differential pathologies associated with syncopal presentation need to be ruled out, which in turn further diminishes resources, especially in a deployed environment that is often in austere, remote locations with a lack of readily available medical supplies. We present a case of vasovagal syncope experienced by a 20-year-old sailor shortly after venipuncture and the 12-lead electrocardiogram captured shortly after presentation. This case highlights the unique electrophysiology during a vasovagal episode and the impact a relatively benign condition has on medical operations in the operational setting.
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Affiliation(s)
- Jose Redondo
- U.S. Military Carrier Air Wing Seventeen, Naval Medical Center San Diego, San Diego, CA 92134, USA
| | - Lisa M Conte
- Department of Cardiology, Walter Reed Military Medical Center, Bethesda, MD 20814, USA
| | - Gilbert Seda
- Intensive Care Unit, Scripps Mercy Chula Vista, Chula Vista, CA 91910, USA
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2
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Cui YX, Du JB, Jin HF. Baroreflex sensitivity and its implication in neurally mediated syncope in children. World J Pediatr 2023; 19:1023-1029. [PMID: 37014537 DOI: 10.1007/s12519-023-00693-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 01/20/2023] [Indexed: 04/05/2023]
Affiliation(s)
- Ya-Xi Cui
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Jun-Bao Du
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
- Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Hong-Fang Jin
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China.
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3
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Yarkoni M, Rehman WU, Bajwa A, Yarkoni A, Rehman AU. Ganglionated Plexus Ablation Procedures to Treat Vasovagal Syncope. Int J Mol Sci 2023; 24:13264. [PMID: 37686062 PMCID: PMC10487499 DOI: 10.3390/ijms241713264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 08/21/2023] [Accepted: 08/23/2023] [Indexed: 09/10/2023] Open
Abstract
Vasovagal syncope (VVS) refers to a heterogeneous group of conditions whereby the cardiovascular reflexes normally controlling the circulation are interrupted irregularly in response to a trigger, resulting in vasodilation, bradycardia, or both. VVS affects one-third of the population at least once in their lifetime or by the age of 60, reduces the quality of life, and may cause disability affecting certain routines. It poses a considerable economic burden on society, and, despite its prevalence, there is currently no proven pharmacological treatment for preventing VVS. The novel procedure of ganglionated plexus (GP) ablation has emerged rapidly in the past two decades, and has been proven successful in treating syncope. Several parameters influence the success rate of GP ablation, including specific ablation sites, localization and surgical techniques, method of access, and the integration of other interventions. This review aims to provide an overview of the existing literature on the physiological aspects and clinical effectiveness of GP ablation in the treatment of VVS. Specifically, we explore the association between GPs and VVS and examine the impact of GP ablation procedures as reported in human clinical trials. Our objective is to shed light on the therapeutic significance of GP ablation in eliminating VVS and restoring normal sinus rhythm, particularly among young adults affected by this condition.
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Affiliation(s)
- Merav Yarkoni
- Heart and Vascular Institute, United Health Services, Johnson City, NY 13790, USA; (W.u.R.); (A.B.); (A.Y.); (A.u.R.)
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4
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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: 0] [Impact Index Per Article: 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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Pawłowski R, Zalewski P, Newton J, Piątkowska A, Koźluk E, Opolski G, Buszko K. An assessment of heart rate and blood pressure asymmetry in the diagnosis of vasovagal syncope in females. Front Physiol 2023; 13:1087837. [PMID: 36699671 PMCID: PMC9868761 DOI: 10.3389/fphys.2022.1087837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 12/20/2022] [Indexed: 01/10/2023] Open
Abstract
Introduction: Heart Rate Asymmetry (HRA) describes a phenomenon of differences between accelerations and decelerations in human heart rate. Methods used for HRA assessment can be further implemented in the evaluation of asymmetry in blood pressure variations (Blood Pressure Asymmetry-BPA). Methods: We have analyzed retrospectively the series of heartbeat intervals extracted from ECG and beat-to-beat blood pressure signals from 16 vasovagal patients (age: 32.1 ± 13.3; BMI: 21.6 ± 3.8; all female) and 19 healthy subjects (age: 34.6 ± 7.6; BMI: 22.1 ± 3.4; all female) who have undergone tilt test (70°). Asymmetry was evaluated with Poincaré plot-based methods for 5 min recordings from supine and tilt stages of the test. The analyzed biosignals were heart rate (RR), diastolic (dBP) and systolic Blood Pressure (sBP) and Pulse Pressure (PP). In the paper we explored the differences between healthy and vasovagal women. Results: The changes of HRA indicators between supine and tilt were observed only in the control group (Porta Index p = 0.026 and Guzik Index p = 0.005). No significant differences in beat-to-beat variability (i.e. spread of points across the line of identity in Poincaré plot-SD1) of dBP was noted between supine and tilt in the vasovagal group (p = 0.433 in comparison to p = 0.014 in healthy females). Moreover, in vasovagal patients the PP was significantly different (supine: 41.47; tilt: 39.27 mmHg) comparing to healthy subjects (supine: 35.87; tilt: 33.50 mmHg) in supine (p = 0.019) and in tilt (p = 0.014). Discussion: Analysis of HRA and BPA represents a promising method for the evaluation of cardiovascular response to orthostatic stressors, however currently it is difficult to determine a subject's underlying health condition based only on these parameters.
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Affiliation(s)
- Rafał Pawłowski
- Department of Biostatistics and Biomedical Systems Theory, Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland,*Correspondence: Rafał Pawłowski,
| | - Paweł Zalewski
- Department of Exercise Physiology and Functional Anatomy, Ludwik Rydygier Collegium Medicum in Bydgoszcz Nicolaus Copernicus University in Torun, Bydgoszcz, Poland,Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Julia Newton
- Population Health Sciences Institute, The Medical School, Newcastle University, Newcastle, United Kingdom
| | - Agnieszka Piątkowska
- Department of Emergency Medicine, Wroclaw Medical University, Wroclaw, Poland,1st Chair and Department of Cardiology, Medical University of Warsaw, Warsaw, Poland
| | - Edward Koźluk
- 1st Chair and Department of Cardiology, Medical University of Warsaw, Warsaw, Poland
| | - Grzegorz Opolski
- 1st Chair and Department of Cardiology, Medical University of Warsaw, Warsaw, Poland
| | - Katarzyna Buszko
- Department of Biostatistics and Biomedical Systems Theory, Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
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Du X, Tao C, Li X, Du J, Liao Y, Jin H. Predicting therapeutic efficacy of oral rehydration salts in children with vasovagal syncope. Front Pediatr 2023; 11:1164304. [PMID: 37124188 PMCID: PMC10133722 DOI: 10.3389/fped.2023.1164304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Accepted: 03/27/2023] [Indexed: 05/02/2023] Open
Abstract
Objective This study was designed to develop an easy-to-perform and inexpensive measure to predict efficacy of the oral rehydration salts (ORS) in children with vasovagal syncope (VVS). Materials and methods Children diagnosed with VVS and treated with ORS for a median of 3 months at the Peking University First Hospital, China, were enrolled and followed up. Demographic data, clinical hemodynamic parameters, and variables related to red blood cells were collected at the baseline. On the basis of changes in symptom scores after treatment, participants were divided into effective or ineffective groups at the end of the follow-up. Logistic regression analysis was used to investigate parameters related to therapeutic efficacy of ORS and a predictive model of ORS effectiveness was created. The predictive efficiency was evaluated using the receiver operating characteristic curve. The accuracy/consistency was evaluated by the Hosmer-Lemeshow test and calibration curve. Internal validation was done using the bootstrap approach. Results Totally 97 pediatric participants were included in the study and 4 (4.1%) were lost during the follow-up. ORS therapy was effective in 46 children and ineffective in 47 children. Children in the effective group had higher baseline red blood cell count, hemoglobin, and hematocrit than those in the ineffective group (p < 0.01). Through logistic regression analysis, the baseline hematocrit and body mass index (BMI) were included in predictive model for the response to ORS treatment. The predictive efficacy of the model showed an area under the curve of 0.77 (p < 0.01). The predicted probability cut-off value of 0.5 was found to be optimal, with a resulting sensitivity of 67.4% and specificity of 80.9%. In the Hosmer-Lemeshow test, p-value was 0.75, and the calibration plot showed a good model fitness. Internal validation was performed using the bootstrap approach (n = 1,000), showing 95% confidence interval of 0.67-0.86. Conclusion Hemoglobin combined with BMI was useful for predicting the therapeutic efficacy of ORS in children with VVS.
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Affiliation(s)
- Xiaojuan Du
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Chunyan Tao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xueying Li
- Department of Statistics, Peking University First Hospital, Beijing, China
| | - Junbao Du
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- State Key Laboratory of Vascular Homeostasis and Remodeling, Peking University, Beijing, China
| | - Ying Liao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- Correspondence: Ying Liao Hongfang Jin
| | - Hongfang Jin
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- Correspondence: Ying Liao Hongfang Jin
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Moore JP, Simpson LL, Drinkhill MJ. Differential contributions of cardiac, coronary and pulmonary artery vagal mechanoreceptors to reflex control of the circulation. J Physiol 2022; 600:4069-4087. [PMID: 35903901 PMCID: PMC9544715 DOI: 10.1113/jp282305] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 07/19/2022] [Indexed: 11/25/2022] Open
Abstract
Distinct populations of stretch‐sensitive mechanoreceptors attached to myelinated vagal afferents are found in the heart and adjoining coronary and pulmonary circulations. Receptors at atrio‐venous junctions appear to be involved in control of intravascular volume. These atrial receptors influence sympathetic control of the heart and kidney, but contribute little to reflex control of systemic vascular resistance. Baroreceptors at the origins of the coronary circulation elicit reflex vasodilatation, like feedback control from systemic arterial baroreceptors, as well as having characteristics that could contribute to regulation of mean pressure. In contrast, feedback from baroreceptors in the pulmonary artery and bifurcation is excitatory and elicits a pressor response. Elevation of pulmonary arterial pressure resets the vasomotor limb of the systemic arterial baroreflex, which could be relevant for control of sympathetic vasoconstrictor outflow during exercise and other states associated with elevated pulmonary arterial pressure. Ventricular receptors, situated mainly in the inferior posterior wall of the left ventricle, and attached to unmyelinated vagal afferents, are relatively inactive under basal conditions. However, a change to the biochemical environment of cardiac tissue surrounding these receptors elicits a depressor response. Some ventricular receptors respond, modestly, to mechanical distortion. Probably, ventricular receptors contribute little to tonic feedback control; however, reflex bradycardia and hypotension in response to chemical activation may decrease the work of the heart during myocardial ischaemia. Overall, greater awareness of heterogeneous reflex effects originating from cardiac, coronary and pulmonary artery mechanoreceptors is required for a better understanding of integrated neural control of circulatory function and arterial blood pressure.
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Affiliation(s)
| | | | - Mark J Drinkhill
- Leeds Institute for Cardiovascular and Metabolic Medicine, Leeds, UK
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Yuan P, Lian Z, Wang Y, Wang Y, Zhang C, Du J, Huang Y, Liao Y. Poincaré Plot Is Useful for Distinguishing Vasovagal Syncope From Postural Tachycardia Syndrome in Children. Front Pediatr 2022; 10:758100. [PMID: 35372154 PMCID: PMC8965582 DOI: 10.3389/fped.2022.758100] [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: 08/13/2021] [Accepted: 02/09/2022] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES To explore the role of the Poincaré plot derived from a 24-hour Holter recording in distinguishing vasovagal syncope (VVS) from postural tachycardia syndrome (POTS) in pediatric patients. MATERIALS AND METHODS Pediatric patients with VVS or POTS, hospitalized in Peking University First Hospital between January 2012 and December 2018, were included in a derivation study. The transverse axis (T), longitudinal axis (L), T/L ratio, product T × L, distance between the origin and the proximal end of the longitudinal axis (pro-D), and distance between the origin and distal end of the longitudinal axis (dis-D) of the Poincaré plot were compared between the VVS and POTS groups, and the differential diagnostic performance of the above-mentioned graphic parameters was evaluated using receiver operating characteristic curve analysis. A validation study was conducted in pediatric patients hospitalized between January 2019 and December 2020. RESULTS In school-aged children, the T, L, T/L, T × L, and dis-D values of patients with VVS were greater than those of patients with POTS; in adolescents, the T, T/L, T × L, and pro-D values of patients with VVS were greater than those of patients with POTS. Using a T/L cut-off value of 0.3 to distinguish between the two diseases, the sensitivity and specificity were 91.0 and 90.5%, respectively, for the total participants; 91.6 and 88.9%, respectively, for the school-aged children; and 82.1 and 95.7%, respectively, for the adolescents. In the validation study, a T/L cut-off value of 0.3 yielded an accuracy, sensitivity, and specificity of 81.8, 87.2, and 77.6%, respectively, in the total participants; 76.5, 82.6, and 71.4%, respectively, in the school-aged children; and 89.2, 93.8, and 85.7%, respectively, in the adolescents, in distinguishing VVS from POTS validated by clinical diagnosis. CONCLUSIONS The graphic parameters of the Poincaré plot are significantly different between VVS and POTS in pediatric patients, and the T/L of the Poincaré plot may be a useful measure to help differentiate VVS from POTS in children and adolescents.
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Affiliation(s)
- Piaoliu Yuan
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Zhouhui Lian
- Wang Xuan Institute of Computer Science, Peking University, Beijing, China
| | - Yuanyuan Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yaru Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Chunyu Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Junbao Du
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China
| | - Yaqian Huang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Ying Liao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
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9
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High Skin Sympathetic Nerve Activity in Patients with Recurrent Syncope. J Pers Med 2021; 11:jpm11111053. [PMID: 34834405 PMCID: PMC8620794 DOI: 10.3390/jpm11111053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/19/2021] [Accepted: 10/19/2021] [Indexed: 11/29/2022] Open
Abstract
(1) Background: The autonomic imbalance plays a role in vasovagal syncope (VVS) diagnosed by head-up tilting test (HUT). neuECG is a new method of recording skin electrical signals to simultaneously analyze skin sympathetic nerve activity (SKNA) and electrocardiogram. We hypothesize that SKNA is higher in subjects with tilt-positive than tilt-negative and the SKNA surges before syncope. (2) Methods: We recorded neuECG in 41 subjects who received HUT (according to the “Italian protocol”), including rest, tilt-up, provocation and recovery phases. Data were analyzed to determine the average SKNA (aSKNA, μV) per digitized sample. Electrocardiogram was used to calculate standard deviation of normal-to-normal beat intervals (SDNN). The “SKNA-SDNN index” was calculated by rest aSKNA multiplied by the ratio of tilt-up to rest SDNN. (3) Results: 16 of 41 (39%) subjects developed syncope. The aSKNA at rest phase is significantly higher in the tilt-positive (1.21 ± 0.27 µV) than tilt-negative subjects (1.02 ± 0.29 µV) (p = 0.034). There are significant surges and withdraw of aSKNA 30 s before and after syncope (both p ≤ 0.006). SKNA-SDNN index is able to predict syncope (p < 0.001). (4) Conclusion: Higher SKNA at rest phase is associated with positive HUT. The SKNA-SDNN index is a novel marker to predict syncope during HUT.
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Raphan T, Yakushin SB. Predicting Vasovagal Responses: A Model-Based and Machine Learning Approach. Front Neurol 2021; 12:631409. [PMID: 33776889 PMCID: PMC7988203 DOI: 10.3389/fneur.2021.631409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 02/12/2021] [Indexed: 11/23/2022] Open
Abstract
Vasovagal syncope (VVS) or neurogenically induced fainting has resulted in falls, fractures, and death. Methods to deal with VVS are to use implanted pacemakers or beta blockers. These are often ineffective because the underlying changes in the cardiovascular system that lead to the syncope are incompletely understood and diagnosis of frequent occurrences of VVS is still based on history and a tilt test, in which subjects are passively tilted from a supine position to 20° from the spatial vertical (to a 70° position) on the tilt table and maintained in that orientation for 10–15 min. Recently, is has been shown that vasovagal responses (VVRs), which are characterized by transient drops in blood pressure (BP), heart rate (HR), and increased amplitude of low frequency oscillations in BP can be induced by sinusoidal galvanic vestibular stimulation (sGVS) and were similar to the low frequency oscillations that presaged VVS in humans. This transient drop in BP and HR of 25 mmHg and 25 beats per minute (bpm), respectively, were considered to be a VVR. Similar thresholds have been used to identify VVR's in human studies as well. However, this arbitrary threshold of identifying a VVR does not give a clear understanding of the identifying features of a VVR nor what triggers a VVR. In this study, we utilized our model of VVR generation together with a machine learning approach to learn a separating hyperplane between normal and VVR patterns. This methodology is proposed as a technique for more broadly identifying the features that trigger a VVR. If a similar feature identification could be associated with VVRs in humans, it potentially could be utilized to identify onset of a VVS, i.e, fainting, in real time.
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Affiliation(s)
- Theodore Raphan
- Department of Computer and Information Science, Institute for Neural and Intelligent Systems, Brooklyn College of CUNY, Brooklyn, NY, United States.,Graduate Center of CUNY, New York, NY, United States
| | - Sergei B Yakushin
- Department of Neurology, Icahn School of Medicine at Mount Sinai Hospital, New York, NY, United States
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Wilmshurst P, Clamp M. Impaired consciousness when scuba diving associated with vasovagal syncope. Diving Hyperb Med 2020; 50:421-423. [PMID: 33325026 DOI: 10.28920/dhm50.4.421-423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 08/29/2020] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Drowning is likely to result from impairment of consciousness when scuba diving. Causes include toxic effects of breathing gas, including nitrogen narcosis and oxygen toxicity, and arterial gas embolism. METHODS Review of the medical records of scuba divers who had impaired consciousness underwater that could not be attributed to toxic effects of breathing gas or arterial gas embolism. RESULTS Four scuba divers had episodes of impaired consciousness when at shallow depths (8-18 m) underwater. The descriptions of the episodes were very similar. Three had histories of recurrent episodes of vasovagal syncope on land. CONLCUSIONS Absence of other causes for their impaired consciousness underwater leads to the conclusion that the probable cause was vasovagal syncope.
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Affiliation(s)
- Peter Wilmshurst
- Royal Stoke University Hospital, Stoke-on-Trent, United Kingdom.,Corresponding author: Dr Peter Wilmshurst, Consultant Cardiologist, Royal Stoke University Hospital, Stoke-on-Trent, ST4 6QG, United Kingdom,
| | - Margaret Clamp
- MC Occupational Health, Colwick, Nottingham, United Kingdom
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12
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Akella K, Olshansky B, Lakkireddy D, Gopinathannair R. Pacing Therapies for Vasovagal Syncope. J Atr Fibrillation 2020; 13:2406. [PMID: 33024506 DOI: 10.4022/jafib.2406] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 02/24/2020] [Accepted: 03/25/2020] [Indexed: 01/02/2023]
Abstract
Vasovagal Syncope (VVS) is mediated by a cardiac autonomic reflex with resultant bradycardia and hypotension, precipitating syncope. While benign and mostly well controlled, recurrent VVS can be debilitating and warrants intervention. Non-pharmacological management of VVS have had variable success. In patients with recurrent cardioinhibitory VVS, permanent pacing can be effective. The utility of pacing to preempt the syncopal depends on the prominent temporal role of bradycardia during the vasovagal reflex. Current guidelines recommend pacing as a therapy to consider in older patients with recurrent VVS. Although younger patients can benefit, one should be cautious given the long-term risk of complications. Available data appears to favor a dual chamber pacemaker with closed loop stimulation algorithm to prevent recurrent cardioinhibitory VVS. Several aspects, including mechanistic understanding of VVS and appropriate patient selection, remain unclear, and require further study.
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Affiliation(s)
- Krishna Akella
- Kansas City Heart Rhythm Institute (KCHRI), Overland Park, KS, USA
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13
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A Novel Assessment of Baroreflex Activity Through the Similarity of Ternary Codes of Oscillations Between Arterial Blood Pressure and R–R Intervals. J Med Biol Eng 2020. [DOI: 10.1007/s40846-020-00557-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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14
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Similar Cerebral Blood Flow and Autonomic Responses to Upright Tilt Test in Adult Patients With Different Hemodynamic Mechanisms Leading to Reflex Syncope. J Clin Neurophysiol 2020; 37:239-245. [DOI: 10.1097/wnp.0000000000000628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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van Dijk JG, van Rossum IA, Thijs RD. Timing of Circulatory and Neurological Events in Syncope. Front Cardiovasc Med 2020; 7:36. [PMID: 32232058 PMCID: PMC7082775 DOI: 10.3389/fcvm.2020.00036] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 02/24/2020] [Indexed: 11/13/2022] Open
Abstract
Syncope usually lasts less than a minute, in which short time arterial blood pressure temporarily falls enough to decrease brain perfusion so much that loss of consciousness ensues. Blood pressure decreases quickest when the heart suddenly stops pumping, which happens in arrhythmia and in severe cardioinhibitory reflex syncope. Loss of consciousness starts about 8 s after the last heart beat and circulatory standstill occurs after 10-15 s. A much slower blood pressure decrease can occur in syncope due to orthostatic hypotension Standing blood pressure can then stabilize at low values often causing more subtle signs (i.e., inability to act) but often not low enough to cause loss of consciousness. Cerebral autoregulation attempts to keep cerebral blood flow constant when blood pressure decreases. In reflex syncope both the quick blood pressure decrease and its low absolute value mean that cerebral autoregulation cannot prevent syncope. It has more protective value in orthostatic hypotension. Neurological signs are related to the severity and timing of cerebral hypoperfusion. Several unanswered pathophysiological questions with possible clinical implications are identified.
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Affiliation(s)
- J Gert van Dijk
- Department of Neurology, Leiden University Medical Centre, Leiden, Netherlands
| | - Ineke A van Rossum
- Department of Neurology, Leiden University Medical Centre, Leiden, Netherlands
| | - Roland D Thijs
- Department of Neurology, Leiden University Medical Centre, Leiden, Netherlands
- Stichting Epilepsie Instellingen Nederland, Heemstede, Netherlands
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Carlos Pachon Mateos J, I Pachón Mateos E, Higuti C, Guilhermo Santillana Peña T, Julio Lobo T, Thiene Cunha Pachón C, Carlos Pachón Mateos J, Carlos Zerpa Acosta J, Ortencio F, Amarante R. Cardioneuroablation: Catheter Vagal Denervation as a New Therapy for Cardioinhibitory Syncope. JOURNAL OF CARDIAC ARRHYTHMIAS 2020. [DOI: 10.24207/jca.v32n3.067_in] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The vasovagal syncope is the most frequent cause of transient loss of consciousness, especially in young people without significant heart disease. The malignant cardioinhibitory form is caused by abrupt and intense vagal reflex with or without defined triggers. Refractory cases to preventive measures and pharmacological handling has been treated with definitive pacemaker implantation. Besides showing questionable results, pacemaker implantation is highly rejected by young patients. In the late 1990s, we proposed specific vagal denervation by catheter ablation and spectral mapping, for paroxysmal AF, functional bradyarrhythmias and severe cases of malignant cardioinhibitory syncope giving rise to cardioneuroablation. Recently, many authors worldwide have been reproducing the cardioneuroablation results where elimination or significant reduction of the vagal response were observed, which abolished symptoms in more than 75% of patients followed up to 14 years, without complications. Therefore, cardioneuroablation has shown to be a real therapeutic option in malignant syncope cardioinhibitory and in any exclusive vagal mediated bradyarrhythmia without the need for pacemaker implantation.
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Affiliation(s)
| | | | | | | | - Tasso Julio Lobo
- Hospital do Coração - Serviço de Eletrofisiologia, Marcapasso e Arritmias - São Paulo (SP) – Brazil
| | | | | | - Juán Carlos Zerpa Acosta
- Hospital do Coração - Serviço de Eletrofisiologia, Marcapasso e Arritmias - São Paulo (SP) – Brazil
| | - Felipe Ortencio
- Hospital do Coração - Serviço de Eletrofisiologia, Marcapasso e Arritmias - São Paulo (SP) – Brazil
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Carlos Pachon Mateos J, I Pachón Mateos E, Higuti C, Guilhermo Santillana Peña T, Julio Lobo T, Thiene Cunha Pachón C, Carlos Pachón Mateos J, Carlos Zerpa Acosta J, Ortencio F, Amarante R. Cardioneuroablação: A Denervação Vagal por Cateter Como Nova Terapia para Síncope Cardioinibitória. JOURNAL OF CARDIAC ARRHYTHMIAS 2020. [DOI: 10.24207/jca.v32n3.067_pt] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
A síncope vasovagal é a causa mais frequente de perda transitória de consciência, especialmente em jovens sem doença cardíaca significativa. A forma cardioinibitória maligna é causada por reflexo vagal abrupto e intenso com ou sem gatilhos definidos. Casos refratários a medidas preventivas e manuseio farmacológico foram tratados com implante definitivo de marcapasso. Além de apresentar resultados questionáveis, o implante de marcapasso é altamente rejeitado por pacientes jovens. No final dos anos 1990, propusemos uma denervação vagal específica por ablação do cateter e mapeamento espectral para FA paroxística, bradiarritmias funcionais e casos graves de síncope cardioinibitória maligna dando origem à cardioneuroablação. Recentemente, muitos autores em todo o mundo vêm reproduzindo os resultados da cardioneuroablação, onde se observou eliminação ou redução significativa da resposta vagal, o que aboliu sintomas em mais de 75% dos pacientes acompanhados por até 14 anos, sem complicações. Portanto a cardioneuroablação tem se mostrado uma verdadeira opção terapêutica na síncope cardioinibitória maligna e em qualquer bradiarritmia vagal exclusiva mediada sem a necessidade de implante de marcapasso.
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Affiliation(s)
| | | | | | | | - Tasso Julio Lobo
- Hospital do Coração - Serviço de Eletrofisiologia, Marcapasso e Arritmias - São Paulo (SP) – Brazil
| | | | | | - Juán Carlos Zerpa Acosta
- Hospital do Coração - Serviço de Eletrofisiologia, Marcapasso e Arritmias - São Paulo (SP) – Brazil
| | - Felipe Ortencio
- Hospital do Coração - Serviço de Eletrofisiologia, Marcapasso e Arritmias - São Paulo (SP) – Brazil
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18
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Deveau AP, Sheldon R, Maxey C, Ritchie D, Doucette S, Parkash R. Sex Differences in Vasovagal Syncope: A Post Hoc Analysis of the Prevention of Syncope Trials (POST) I and II. Can J Cardiol 2019; 36:79-83. [PMID: 31810744 DOI: 10.1016/j.cjca.2019.10.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/14/2019] [Accepted: 10/02/2019] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Vasovagal syncope (VVS) occurs in > 40% of individuals at least once in their lifetime. Sex-dependent differences in presentation and outcomes are not understood. We sought to determine differences in clinical presentation, treatment modalities, and outcomes of VVS between men and women. METHODS Data were collected as part of the Prevention of Syncope Trials (POST) I and II, 2 multicenter, placebo-controlled, randomized trials testing the effectiveness of metoprolol and fludrocortisone, respectively. Data regarding clinical presentation, outcomes, and time to first syncope event after randomization were compared. RESULTS Of the 418 patients (280 women and 138 men), women were younger at the time of first syncope event (21 vs 26 years P = 0.002) and had a lower baseline systolic blood pressure (117 vs 124 mm Hg, P < 0.001). Response to heat as a trigger for syncope was more common in women (68% vs 48%, P = 0.011). Clinical presentation in women consisted more commonly of feeling warm, having seizures, and experiencing more postsyncope fatigue (68% vs 54%, P = 0.048; 10% vs 2.7%, P = 0.045; 75% vs 59%, P = 0.017, respectively). Women were more likely to experience recurrent syncope after adjustment for prerandomization syncope burden and randomization assignment (hazard ratio, 1.56; 95% confidence interval, 1.10-2.22; P = 0.012). CONCLUSION Clinical presentation and provocative factors of VVS differ between men and women, as do recurrent events. Recognition of these differences may help target therapy specifically in men and women.
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Affiliation(s)
- Adam P Deveau
- Dalhousie University Medical School, Halifax, Nova Scotia, Canada
| | | | | | | | - Steve Doucette
- Research Methods Unit, Nova Scotia Health Authority, Halifax, Nova Scotia, Canada
| | - Ratika Parkash
- Queen Elizabeth II Health Sciences Centre, Halifax, Nova Scotia, Canada.
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Cardiac and Vascular Sympathetic Baroreflex Control during Orthostatic Pre-Syncope. J Clin Med 2019; 8:jcm8091434. [PMID: 31510103 PMCID: PMC6781174 DOI: 10.3390/jcm8091434] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/04/2019] [Accepted: 09/05/2019] [Indexed: 11/17/2022] Open
Abstract
We hypothesized that sympathetic baroreflex mediated uncoupling between neural sympathetic discharge pattern and arterial pressure (AP) fluctuations at 0.1 Hz during baroreceptor unloading might promote orthostatic pre-syncope. Ten volunteers (32 ± 6 years) underwent electrocardiogram, beat-to-beat AP, respiratory activity and muscle sympathetic nerve activity (MSNA) recordings while supine (REST) and during 80° head-up tilt (HUT) followed by -10 mmHg stepwise increase of lower body negative pressure until pre-syncope. Cardiac and sympathetic baroreflex sensitivity were quantified. Spectrum analysis of systolic and diastolic AP (SAP and DAP) and calibrated MSNA (cMSNA) variability assessed the low frequency fluctuations (LF, ~0.1 Hz) of SAP, DAP and cMSNA variability. The squared coherence function (K2) quantified the coupling between cMSNA and DAP in the LF band. Analyses were performed while supine, during asymptomatic HUT (T1) and at pre-syncope onset (T2). During T2 we found that: (1) sympathetic baroreceptor modulation was virtually abolished compared to T1; (2) a progressive decrease in AP was accompanied by a persistent but chaotic sympathetic firing; (3) coupling between cMSNA and AP series at 0.1 Hz was reduced compared to T1. A negligible sympathetic baroreceptor modulation during pre-syncope might disrupt sympathetic discharge pattern impairing the capability of vessels to constrict and promote pre-syncope.
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20
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Does A Therapy for Reflex Vasovagal Syncope Really Exist? High Blood Press Cardiovasc Prev 2019; 26:273-281. [DOI: 10.1007/s40292-019-00327-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 07/01/2019] [Indexed: 10/26/2022] Open
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Goswami N, Blaber AP, Hinghofer-Szalkay H, Convertino VA. Lower Body Negative Pressure: Physiological Effects, Applications, and Implementation. Physiol Rev 2019; 99:807-851. [PMID: 30540225 DOI: 10.1152/physrev.00006.2018] [Citation(s) in RCA: 117] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
This review presents lower body negative pressure (LBNP) as a unique tool to investigate the physiology of integrated systemic compensatory responses to altered hemodynamic patterns during conditions of central hypovolemia in humans. An early review published in Physiological Reviews over 40 yr ago (Wolthuis et al. Physiol Rev 54: 566-595, 1974) focused on the use of LBNP as a tool to study effects of central hypovolemia, while more than a decade ago a review appeared that focused on LBNP as a model of hemorrhagic shock (Cooke et al. J Appl Physiol (1985) 96: 1249-1261, 2004). Since then there has been a great deal of new research that has applied LBNP to investigate complex physiological responses to a variety of challenges including orthostasis, hemorrhage, and other important stressors seen in humans such as microgravity encountered during spaceflight. The LBNP stimulus has provided novel insights into the physiology underlying areas such as intolerance to reduced central blood volume, sex differences concerning blood pressure regulation, autonomic dysfunctions, adaptations to exercise training, and effects of space flight. Furthermore, approaching cardiovascular assessment using prediction models for orthostatic capacity in healthy populations, derived from LBNP tolerance protocols, has provided important insights into the mechanisms of orthostatic hypotension and central hypovolemia, especially in some patient populations as well as in healthy subjects. This review also presents a concise discussion of mathematical modeling regarding compensatory responses induced by LBNP. Given the diverse applications of LBNP, it is to be expected that new and innovative applications of LBNP will be developed to explore the complex physiological mechanisms that underline health and disease.
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Affiliation(s)
- Nandu Goswami
- Physiology Section, Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz , Graz , Austria ; Department of Biomedical Physiology and Kinesiology, Simon Fraser University , Burnaby, British Columbia , Canada ; Battlefield Health & Trauma Center for Human Integrative Physiology, Combat Casualty Care Research Program, US Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
| | - Andrew Philip Blaber
- Physiology Section, Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz , Graz , Austria ; Department of Biomedical Physiology and Kinesiology, Simon Fraser University , Burnaby, British Columbia , Canada ; Battlefield Health & Trauma Center for Human Integrative Physiology, Combat Casualty Care Research Program, US Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
| | - Helmut Hinghofer-Szalkay
- Physiology Section, Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz , Graz , Austria ; Department of Biomedical Physiology and Kinesiology, Simon Fraser University , Burnaby, British Columbia , Canada ; Battlefield Health & Trauma Center for Human Integrative Physiology, Combat Casualty Care Research Program, US Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
| | - Victor A Convertino
- Physiology Section, Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz , Graz , Austria ; Department of Biomedical Physiology and Kinesiology, Simon Fraser University , Burnaby, British Columbia , Canada ; Battlefield Health & Trauma Center for Human Integrative Physiology, Combat Casualty Care Research Program, US Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
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22
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Tao C, Chen S, Li H, Wang Y, Wang Y, Liu P, Liao Y, Zhang C, Tang C, Jin H, Du J. Value of Immediate Heart Rate Alteration From Supine to Upright in Differential Diagnosis Between Vasovagal Syncope and Postural Tachycardia Syndrome in Children. Front Pediatr 2018; 6:343. [PMID: 30510926 PMCID: PMC6252323 DOI: 10.3389/fped.2018.00343] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 10/23/2018] [Indexed: 11/13/2022] Open
Abstract
Objectives: To explore the predictive value of immediate heart rate alteration from supine to upright in the differential diagnosis between vasovagal syncope (VVS) and postural tachycardia syndrome (POTS) in children. Materials and Methods: A total of 76 pediatric outpatients or inpatients who visited the Peking University First Hospital from July 2016 to November 2017 were recruited in the study. Among them, 52 patients were diagnosed with VVS and 24 patients were diagnosed with POTS. The differential diagnostic value of acceleration index (AI) and 30/15 ratio was evaluated by the receiver operating characteristic (ROC) curve. An external validation test was performed in another 46 patients. Results: Compared with the cases in the VVS group, patients in the POTS group had a significantly increased AI but a decreased 30/15 ratio (33.495 ± 8.472 vs. 23.440 ± 8.693, p < 0.001; 0.962 ± 0.067 vs. 1.025 ± 0.084, p = 0.002; respectively). The ROC curves showed that AI and 30/15 ratio were useful for differentiating POTS from VVS. A cut-off value of AI set at 28.180 yielded a sensitivity of 79.2% and a specificity of 73.1%. A cut-off value of 30/15 ratio set at 1.025 yielded a sensitivity of 87.5% and a specificity of 61.5%. A combined use of these two indices improved the sensitivity to 95.8% when either AI or 30/15 was used, and specificity to 80.8% with the use of both AI and 30/15 at the same diagnosis. The external validation test showed that the positive and negative predictive values of the AI and 30/15 ratio were 77.3 and 79.2%, and 72.0 and 81.0%, respectively. The positive predictive value increased to 87.5% when both the AI and 30/15 ratio cut-off values were used together. Conclusions: The AI and 30/15 ratio, which are easy to perform and non-invasive, have proper sensitivity and specificity to differentiate patients with POTS from those with VVS. The combination of these two indices significantly improves the predictive value.
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Affiliation(s)
- Chunyan Tao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Selena Chen
- Division of Biological Sciences, University of California, San Diego, San Diego, CA, United States
| | - Hongxia Li
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yuanyuan Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yuli Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Ping Liu
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Ying Liao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Chunyu Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Chaoshu Tang
- Department of Physiology and Pathophysiology, Peking University Health Sciences Centre, Beijing, China
| | - Hongfang Jin
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Junbao Du
- Department of Pediatrics, Peking University First Hospital, Beijing, China
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23
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Gopinathannair R, Salgado BC, Olshansky B. Pacing for Vasovagal Syncope. Arrhythm Electrophysiol Rev 2018; 7:95-102. [PMID: 29967681 PMCID: PMC6020179 DOI: 10.15420/aer.2018.22.2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 05/03/2018] [Indexed: 12/28/2022] Open
Abstract
Vasovagal syncope (VVS) is due to a common autonomic reflex involving the cardiovascular system. It is associated with bradycardia (cardioinhibitory response) and/or hypotension (vasodepressor response), likely mediated by parasympathetic activation and sympathetic inhibition. While generally a situational, isolated and/or self-limited event, for some, VVS is recurrent, unpredictable and debilitating. Conservative, non-pharmacological management may help, but no specific medical therapy has been proven widely effective. Permanent pacing may have specific benefit, but its value has been debated. The temporal causative association of bradycardia with syncope in those with VVS may help identify which patient could benefit from pacing but the timing and type of pacing in lieu of blood pressure changes may be critical. The mode, rate, pacing algorithm and time to initiate dual-chamber pacing preferentially with respect to the vasovagal reflex may be important to prevent or ameliorate the faint but completely convincing data are not yet available. Based on available data, DDD pacing with the closed loop stimulation algorithm appears a viable, if not the best, alternative presently to prevent recurrent VVS episodes. While several knowledge gaps remain, permanent pacing appears to have a role in managing select patients with VVS.
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Affiliation(s)
| | - Benjamin C Salgado
- Division of Cardiovascular Medicine, University of LouisvilleLouisville, USA
| | - Brian Olshansky
- Mercy Heart and Vascular Institute, Mason City; and the University of Iowa HospitalsIowa City, USA
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Xiang L, Hinojosa-Laborde C, Ryan KL, Rickards CA, Convertino VA. Time course of compensatory physiological responses to central hypovolemia in high- and low-tolerant human subjects. Am J Physiol Regul Integr Comp Physiol 2018; 315:R408-R416. [PMID: 29668322 DOI: 10.1152/ajpregu.00361.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Lower body negative pressure (LBNP) simulates hemorrhage in human subjects. Most subjects (67%) exhibited high tolerance (HT) to hypovolemia, while the remainder (33%) had low tolerance (LT). To investigate the mechanisms for decompensation to central hypovolemia in HT and LT subjects, we characterized the time course of total peripheral resistance (TPR), heart rate (HR), and muscle sympathetic nerve activity (MSNA) during LBNP to tolerance determined by the onset of decompensation (presyncope, PS). We hypothesized that 1) maximum (Max) TPR, HR, and MSNA would coincide, and 2) PS would result from simultaneous decreases in TPR, HR, and MSNA in LT and HT subjects but occur earlier in LT than in HT subjects. Max TPR was lower and occurred earlier in LT ( n = 59) than in HT ( n = 113) subjects (LT: 24 ± 1 mmHg·min·1-1 at 756 ± 31 s; HT: 28 ± 1 mmHg·min·1-1 at 1,265 ± 37 s, P < 0.01). Max TPR occurred several minutes before PS. During subsequent decrease in TPR, HR and MSNA continued to increase. Max HR (LT: 111 ± 2 beat/min at 923 ± 27 s; HT: 130 ± 2 beats/min at 1489 ± 23 s, P < 0.01) occurred several seconds before PS. Higher MSNA ( P < 0.01) was attained in HT ( n = 10; 51 ± 5 bursts/min at max TPR; 54 ± 5 bursts/min at max HR) than LT subjects ( n = 4; 41 ± 8 bursts/min at max TPR; 39 ± 8 bursts/min at max HR). The onset of cardiovascular decompensation is a biphasic process in which vasodilation occurs before bradycardia and sympathetic withdrawal. This pattern was similar in LT and HT but occurred earlier in LT subjects. We conclude that sudden bradycardia plays a critical role in the determination of tolerance to central hypovolemia.
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Affiliation(s)
- Lusha Xiang
- United States Army Institute of Surgical Research, Joint Base San Antonio Fort Sam Houston, San Antonio, Texas
| | - Carmen Hinojosa-Laborde
- United States Army Institute of Surgical Research, Joint Base San Antonio Fort Sam Houston, San Antonio, Texas
| | - Kathy L Ryan
- United States Army Institute of Surgical Research, Joint Base San Antonio Fort Sam Houston, San Antonio, Texas
| | - Caroline A Rickards
- Institute for Cardiovascular and Metabolic Disease, University of North Texas Health Science Center , Fort Worth, Texas
| | - Victor A Convertino
- United States Army Institute of Surgical Research, Joint Base San Antonio Fort Sam Houston, San Antonio, Texas.,United States Army Medical Research and Materiel Command, Fort Detrick, Frederick, Maryland
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25
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Brignole M, Moya A, de Lange FJ, Deharo JC, Elliott PM, Fanciulli A, Fedorowski A, Furlan R, Kenny RA, Martín A, Probst V, Reed MJ, Rice CP, Sutton R, Ungar A, van Dijk JG. 2018 ESC Guidelines for the diagnosis and management of syncope. Eur Heart J 2018; 39:1883-1948. [PMID: 29562304 DOI: 10.1093/eurheartj/ehy037] [Citation(s) in RCA: 964] [Impact Index Per Article: 160.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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26
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Heyer GL, Boles LH, Harvey RA, Cismowski MJ. Gastric myoelectrical and neurohormonal changes associated with nausea during tilt-induced syncope. Neurogastroenterol Motil 2018; 30. [PMID: 28960795 DOI: 10.1111/nmo.13220] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Accepted: 09/07/2017] [Indexed: 02/08/2023]
Abstract
BACKGROUND Nausea is a common prodromal symptom of neurally mediated syncope, but the biological factors linking nausea with syncope have not been studied. We aimed to characterize nausea during tilt-induced syncope by exploring related changes in gastric myoelectrical activity and plasma epinephrine, norepinephrine, and vasopressin concentrations across study phases of recumbency, tilt, syncope, and recovery. METHODS Electrogastrographic and plasma hormone changes were compared between patients with tilt-induced syncope and nausea (n = 18) and control subjects (n = 6) without symptoms or hemodynamic changes during tilt-table testing. KEY RESULTS Over a 4-minute period preceding syncope, sequential electrogastrography epochs demonstrated an increase over time in bradygastria (P = .003) and tachygastria (P = .014) power ratios, while the dominant frequency (P < .001) and the percent normogastria (P = .004) decreased. Syncope led to significant differences between cases and controls in electrogastrographic power ratios in each frequency range: bradygastria (P = .001), tachygastria (P = .005), and normogastria (P = .03). Nausea always followed electrogastrographic changes, and nausea resolution always preceded electrogastrographic normalization. Plasma vasopressin (676.5 ± 122.8 vs 91.2 ± 15.3 pg/mL, P = .012) and epinephrine (434 ± 91.3 vs 48.7 ± 2.5 pg/mL, P = .03), but not norepinephrine (P > .05), also differed with syncope between cases and controls. CONCLUSIONS AND INFERENCES The nausea related to tilt-induced syncope is temporally associated with changes in gastric myoelectrical activity and increases in plasma vasopressin and epinephrine. The biological mechanisms that induce syncope are physiologically distinct from other experimental models of nausea such as illusory self-motion, yet nausea with syncope appears to have similarly associated electrogastrographic and hormone changes. Thus, tilt-induced syncope could serve as an informative experimental model for nausea research.
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Affiliation(s)
- G L Heyer
- Division of Pediatric Neurology, Nationwide Children's Hospital, Columbus, OH, USA.,Department of Pediatrics, Nationwide Children's Hospital, Columbus, OH, USA
| | - L H Boles
- Department of Medicine, The Ohio State University, Columbus, OH, USA
| | - R A Harvey
- Department of Pediatrics, Nationwide Children's Hospital, Columbus, OH, USA
| | - M J Cismowski
- Department of Pediatrics, Nationwide Children's Hospital, Columbus, OH, USA.,Center for Cardiovascular Research, Nationwide Children's Hospital, Columbus, OH, USA
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He W, Wang X, Liu S, Yu X, Lu Z, Ma R, Luo D, Xie J, He B, Jiang H. Sympathetic mechanisms in an animal model of vasovagal syncope. Clin Auton Res 2018; 28:333-340. [DOI: 10.1007/s10286-018-0503-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 01/11/2018] [Indexed: 11/24/2022]
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28
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Jeong G, Shin SM, Kim NS, Ahn YM. Sudden unexpected cardio-respiratory arrest after venipuncture in children. KOREAN JOURNAL OF PEDIATRICS 2018; 61:108-113. [PMID: 29713356 PMCID: PMC5924841 DOI: 10.3345/kjp.2018.61.4.108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 12/14/2017] [Accepted: 12/29/2017] [Indexed: 11/27/2022]
Abstract
Purpose This study aimed to investigate the clinical and socioenvironmental characteristics of sudden cardiorespiratory arrest after venipuncture in children. Methods We conducted a retrospective email-based survey of all members of the Korean Pediatric Society. The questionnaire included items on patient demographics, socioenvironmental circumstances of the venipuncture, type of cardiorespiratory arrest, symptoms and signs, treatment, prognosis, and presumed cause of the arrest. Results Fourteen patients were identified. Of these, 13 were young children (<2 years old), and 1 was 14 years old. All patients had been previously healthy and had no specific risk factors for sudden cardiorespiratory arrest. Most cases (n=11, 79%) were defined as cardiac or cardiorespiratory arrest, while the remaining cases (n=3, 21%) were defined as respiratory arrest. Aspiration (n=3), acute myocarditis (n=2), and laryngeal chemoreflex (n=1) were presumed as the causes; however, the exact causes were unclear. The overall prognosis was poor (death, n=7; morbidity, n=5; full recovery, n=2). The medical institutions faced severe backlash because of these incidents (out-of-court settlement, n=5; medical lawsuit, n=5; continuous harassment, n=3). Conclusion Cardiorespiratory arrest after venipuncture is unpredictable and the probable cause of most cases is a vasovagal reaction. Medical personnel must be aware of the risk of unexpected cardiorespiratory arrest during routine intravenous procedures.
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Affiliation(s)
- Goun Jeong
- Department of Pediatrics, Cheil General Hospital and Women's Healthcare Center, Dankook University College of Medicine, Seoul, Korea
| | - Son Moon Shin
- Department of Pediatrics, Cheil General Hospital and Women's Healthcare Center, Dankook University College of Medicine, Seoul, Korea
| | - Nam Su Kim
- Department of Pediatrics, Hanyang University College of Medicine, Seoul, Korea
| | - Young Min Ahn
- Department of Pediatrics, Eulji General Hospital, Eulji University School of Medicine, Seoul, Korea
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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: 87] [Impact Index Per Article: 12.4] [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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Lee SH, Yang JH, Yim HR, Park J, Park SJ, Park KM, On YK, Kim JS. Hemodynamic parameters and baroreflex sensitivity during head-up tilt test in patients with neurally mediated syncope. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2017; 40:1454-1461. [PMID: 29023796 DOI: 10.1111/pace.13217] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 08/01/2017] [Accepted: 10/01/2017] [Indexed: 11/29/2022]
Abstract
BACKGROUND We aimed to investigate differences in hemodynamic parameters and the role of baroreflex sensitivity (BRS) in patients with a history of neurally mediated syncope (NMS) compared with a control group. METHODS Hemodynamic parameters and BRS were continuously measured noninvasively using a Finometer at rest and during passive head-up tilt test (HUT) in patients with a history of NMS (n = 55) and a control group (n = 77). The tilting period was divided into pretest (resting supine position), initial (first 3 minutes of tilting), last (last 3 minutes of tilting), and recovery (3 minutes after tilting was complete) periods. RESULTS Decrease in systolic blood pressure (- 14.7 ± 15.7 mm Hg vs - 7.6 ± 14.3 mm Hg, P < 0.01) was more prominent and increase in total systemic peripheral resistance was significantly smaller (67.6 ± 418.7 dyn.s/cm5 vs 189.4 ± 261.0 dyn.s/cm5 , P = 0.04) from the initial to the last period of HUT in the patient group compared with the control group. BRS was significantly higher during the pretest period (20.1 ± 10.9 ms/mm Hg vs 13.0 ± 8.1 ms/mm Hg, P < 0.01) in the patient group, while the decrease in BRS from the pretest to the initial period was greater (-8.5 ± 6.0 ms/mm Hg vs - 3.2 ± 4.1 ms/mm Hg, P = 0.01). CONCLUSIONS Dysfunctional BRS in response to orthostatic stress might be involved in pathological autonomic cardiac modulation of NMS.
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Affiliation(s)
- Sung Ho Lee
- Division of Cardiology, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Ji Hyun Yang
- Korea Association of Health Promotion, Seoul, Republic of Korea
| | - Hye Ran Yim
- Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Jungwae Park
- Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Seung-Jung Park
- Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Kyoung-Min Park
- Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Young Keun On
- Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - June Soo Kim
- Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
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Lund A, Sørensen H, Jensen TW, Niemann MJ, Olesen ND, Nielsen HB, Olsen NV, Secher NH. Muscle oxygen saturation increases during head-up tilt-induced (pre)syncope. Acta Physiol (Oxf) 2017; 221:74-80. [PMID: 28262007 DOI: 10.1111/apha.12863] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 02/18/2017] [Accepted: 02/23/2017] [Indexed: 11/28/2022]
Abstract
AIM To evaluate whether muscle vasodilatation plays a role for hypotension developed during central hypovolaemia, muscle oxygenation (Sm O2 ) was examined during (pre)syncope induced by head-up tilt (HUT). Skin blood flow (SkBF) and oxygenation (Sskin O2 ) were determined because evaluation of Sm O2 may be affected by superficial tissue oxygenation. Furthermore, we evaluated cerebral oxygenation (Sc O2 ) and middle cerebral artery mean blood flow velocity (MCAvmean ). METHODS Twenty healthy male volunteers (median age 24 years; range 19-38) were subjected to passive 50° HUT for 1 h or until (pre)syncope. Sc O2 and Sm O2 (near-infrared spectroscopy), MCAvmean (transcranial Doppler) along with mean arterial pressure (MAP), heart rate (HR), stroke volume (SV), cardiac output (CO) and total peripheral resistance (TPR) (Modelflow® ) were determined. RESULTS (Pre)syncopal symptoms appeared in 17 subjects after 11 min (median; range 2-34) accompanied by a decrease in MAP, SV, CO and TPR, while HR remained elevated. During (pre)syncope, Sc O2 decreased [73% (71-76; mean and 95% CI) to 68% (65-71), P < 0.0001] along with MCAvmean [40 (37-43) to 32 (29-35) cm s-1 , P < 0.0001]. In contrast, Sm O2 increased [63 (56-69)% to 71% (65-78), P < 0.0001], while Sskin O2 [64% (58-69) to 53% (47-58), P < 0.0001] and SkBF [71 (44-98) compared to a baseline of 99 (72-125) units, P = 0.020] were reduced. CONCLUSION We confirm that the decrease in MAP during HUT is associated with a reduction in indices of cerebral perfusion. (Pre)syncope was associated with an increase in Sm O2 despite reduced Sskin O2 and SkBF, supporting that muscle vasodilation plays an important role in the circulatory events leading to hypotension during HUT.
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Affiliation(s)
- A. Lund
- Department of Neuroanaesthesia; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
| | - H. Sørensen
- The Copenhagen Muscle Research Centre; Department of Anaesthesia; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
| | - T. W. Jensen
- The Copenhagen Muscle Research Centre; Department of Anaesthesia; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
| | - M. J. Niemann
- The Copenhagen Muscle Research Centre; Department of Anaesthesia; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
| | - N. D. Olesen
- The Copenhagen Muscle Research Centre; Department of Anaesthesia; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
- Department of Neuroscience and Pharmacology; University of Copenhagen; Copenhagen Denmark
| | - H. B. Nielsen
- The Copenhagen Muscle Research Centre; Department of Anaesthesia; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
| | - N. V. Olsen
- Department of Neuroanaesthesia; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
- Department of Neuroscience and Pharmacology; University of Copenhagen; Copenhagen Denmark
| | - N. H. Secher
- The Copenhagen Muscle Research Centre; Department of Anaesthesia; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
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Cohen B, Martinelli GP, Xiang Y, Raphan T, Yakushin SB. Vestibular Activation Habituates the Vasovagal Response in the Rat. Front Neurol 2017; 8:83. [PMID: 28360882 PMCID: PMC5350135 DOI: 10.3389/fneur.2017.00083] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 02/24/2017] [Indexed: 12/16/2022] Open
Abstract
Vasovagal syncope is a significant medical problem without effective therapy, postulated to be related to a collapse of baroreflex function. While some studies have shown that repeated static tilts can block vasovagal syncope, this was not found in other studies. Using anesthetized, male Long–Evans rats that were highly susceptible to generation of vasovagal responses, we found that repeated activation of the vestibulosympathetic reflex (VSR) with ±2 and ±3 mA, 0.025 Hz sinusoidal galvanic vestibular stimulation (sGVS) caused incremental changes in blood pressure (BP) and heart rate (HR) that blocked further generation of vasovagal responses. Initially, BP and HR fell ≈20–50 mmHg and ≈20–50 beats/min (bpm) into a vasovagal response when stimulated with Sgv\S in susceptible rats. As the rats were continually stimulated, HR initially rose to counteract the fall in BP; then the increase in HR became more substantial and long lasting, effectively opposing the fall in BP. Finally, the vestibular stimuli simply caused an increase in BP, the normal sequence following activation of the VSR. Concurrently, habituation caused disappearance of the low-frequency (0.025 and 0.05 Hz) oscillations in BP and HR that must be present when vasovagal responses are induced. Habituation also produced significant increases in baroreflex sensitivity (p < 0.001). Thus, repeated low-frequency activation of the VSR resulted in a reduction and loss of susceptibility to development of vasovagal responses in rats that were previously highly susceptible. We posit that reactivation of the baroreflex, which is depressed by anesthesia and the disappearance of low-frequency oscillations in BP and HR are likely to be critically involved in producing resistance to the development of vasovagal responses. SGVS has been widely used to activate muscle sympathetic nerve activity in humans and is safe and well tolerated. Potentially, it could be used to produce similar habituation of vasovagal syncope in humans.
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Affiliation(s)
- Bernard Cohen
- Department of Neurology, Icahn School of Medicine at Mount Sinai , New York, NY , USA
| | - Giorgio P Martinelli
- Department of Neurology, Icahn School of Medicine at Mount Sinai , New York, NY , USA
| | - Yongqing Xiang
- Department of Computer and Information Science, Brooklyn College, City University of New York , New York, NY , USA
| | - Theodore Raphan
- Department of Computer and Information Science, Brooklyn College, City University of New York , New York, NY , USA
| | - Sergei B Yakushin
- Department of Neurology, Icahn School of Medicine at Mount Sinai , New York, NY , USA
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Márquez MF, Gómez-Flores JR, González-Hermosillo JA, Ruíz-Siller TDJ, Cárdenas M. [Role of the sympathetic nervous system in vasovagal syncope and rationale for beta-blockers and norepinephrine transporter inhibitors]. Medwave 2016; 16:e6824. [PMID: 28055999 DOI: 10.5867/medwave.2016.6824] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Vasovagal or neurocardiogenic syncope is a common clinical situation and, as with other entities associated with orthostatic intolerance, the underlying condition is a dysfunction of the autonomic nervous system. This article reviews various aspects of vasovagal syncope, including its relationship with orthostatic intolerance and the role of the autonomic nervous system in it. A brief history of the problem is given, as well as a description of how the names and associated concepts have evolved. The response of the sympathetic system to orthostatic stress, the physiology of the baroreflex system and the neurohumoral changes that occur with standing are analyzed. Evidence is presented of the involvement of the autonomic nervous system, including studies of heart rate variability, microneurography, cardiac innervation, and molecular genetic studies. Finally, we describe different studies on the use of beta-blockers and norepinephrine transporter inhibitors (sibutramine, reboxetine) and the rationality of their use to prevent this type of syncope.
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Affiliation(s)
- Manlio F Márquez
- Departamento de Electrofisiología, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de México, México. Address: Juan Badiano 1, Colonia Sección XVI, Delegación Tlalpan, Distrito Federal, México.
| | - Jorge Rafael Gómez-Flores
- Departamento de Electrofisiología, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de México, México
| | - Jesús A González-Hermosillo
- Departamento de Proyectos de Innovación y Desarrollo, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de México, México
| | | | - Manuel Cárdenas
- Departamento de Electrofisiología, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de México, México
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Fu Q, Levine BD. Syncope prevention in blood donors: when to do what? Transfusion 2016; 56:2399-2402. [DOI: 10.1111/trf.13775] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 07/18/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Qi Fu
- Institute for Exercise and Environmental Medicine; Texas Health Presbyterian Hospital Dallas; Dallas TX
| | - Benjamin D. Levine
- Institute for Exercise and Environmental Medicine; Texas Health Presbyterian Hospital Dallas; Dallas TX
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McBride DW, Reis C, Frank E, Klebe DW, Zhang JH, Applegate R, Tang J. An Experimental Model of Vasovagal Syncope Induces Cerebral Hypoperfusion and Fainting-Like Behavior in Awake Rats. PLoS One 2016; 11:e0163280. [PMID: 27658057 PMCID: PMC5033448 DOI: 10.1371/journal.pone.0163280] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 09/05/2016] [Indexed: 11/25/2022] Open
Abstract
Vasovagal syncope, a contributing factor to elderly falls, is the transient loss of consciousness caused by decreased cerebral perfusion. Vasovagal syncope is characterized by hypotension, bradycardia, and reduced cerebral blood flow, resulting in fatigue, altered coordination, and fainting. The purpose of this study is to develop an animal model which is similar to human vasovagal syncope and establish an awake animal model of vasovagal syncope. Male Sprague-Dawley rats were subjected to sinusoidal galvanic vestibular stimulation (sGVS). Blood pressure, heart rate, and cerebral blood flow were monitored before, during, and post-stimulation. sGVS resulted in hypotension, bradycardia, and decreased cerebral blood flow. One cohort of animals was subjected to sGVS while freely moving. sGVS in awake animals produced vasovagal syncope-like symptoms, including fatigue and uncoordinated movements; two animals experienced spontaneous falling. Another cohort of animals was preconditioned with isoflurane for several days before being subjected to sGVS. Isoflurane preconditioning before sGVS did not prevent sGVS-induced hypotension or bradycardia, yet isoflurane preconditioning attenuated sGVS-induced cerebral blood flow reduction. The sGVS rat model mimics elements of human vasovagal syncope pathophysiology (hypotension, bradycardia, and decreased cerebral perfusion), including behavioral symptoms such as fatigue and altered balance. This study indicates that the sGVS rat model is similar to human vasovagal syncope and that therapies directed at preventing cerebral hypoperfusion may decrease syncopal episodes and reduce injuries from syncopal falls.
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Affiliation(s)
- Devin W. McBride
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, California, United States of America
| | - Cesar Reis
- Department of Anesthesiology, Loma Linda University, Loma Linda, California, United States of America
| | - Ethan Frank
- Loma Linda University School of Medicine, Loma Linda, California, United States of America
| | - Damon W. Klebe
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, California, United States of America
| | - John H. Zhang
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, California, United States of America
- Department of Neurosurgery, Loma Linda University, Loma Linda, California, United States of America
| | - Richard Applegate
- Department of Anesthesiology, Loma Linda University, Loma Linda, California, United States of America
| | - Jiping Tang
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, California, United States of America
- * E-mail:
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Chaddha A, Wenzke KE, Brignole M, Wasmund SL, Page RL, Hamdan MH. The Role of the Baroreflex in Tilt Table Testing: Outcome and Type of Response. JACC Clin Electrophysiol 2016; 2:812-817. [PMID: 29759765 DOI: 10.1016/j.jacep.2016.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 04/29/2016] [Accepted: 05/12/2016] [Indexed: 10/21/2022]
Abstract
OBJECTIVES The purpose of this study was to better understand the role of the baroreflex in tilt-induced vasovagal syncope (VVS). BACKGROUND The role of the baroreflex in tilt-induced VVS remains controversial. The authors hypothesized that: 1) patients with positive tilt table test (TTT) results have greater baroreflex gain (BRG) compared with patients with negative TTT results; and 2) patients with tilt-induced asystole have greater BRG compared with patients without asystole. METHODS Using the sequence method, BRG measurements were obtained in 438 consecutive patients undergoing TTT. Two hundred sixty-eight patients (61%) had positive TTT results (mean age 50 ± 21 years; 34% men), and 170 patients (39%) had negative TTT results (mean age 48 ± 21 years; 35% men). RESULTS Mean BRG was significantly higher in patients with positive TTT results compared with those with negative TTT results (12.9 ± 6.0 ms/mm Hg vs. 11.5 ± 6.0 ms/mm Hg; p = 0.01). Among the 268 patients with positive TTT results, 23 (9%) had more than 3 s of asystole (mean age 37 ± 17; 30% men), and 245 patients had a mixed vasodepressor or cardioinhibitory response without asystole (mean age 51 ± 17 years; 34% men). Mean BRG was greater in patients with tilt-induced asystole (>3 s) compared with patients without asystole (15.3 ± 5.9 ms/mm Hg vs. 12.7 ± 5.9 ms/mm Hg; p = 0.03). CONCLUSIONS The results of this study demonstrate that baseline BRG was higher in patients with positive TTT results compared with those with negative TTT results, with greater values noted in patients with tilt-induced asystole (>3 s) compared with those without asystole.
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Affiliation(s)
- Ashish Chaddha
- Division of Cardiovascular Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Kevin E Wenzke
- Division of Cardiovascular Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Michele Brignole
- Division of Cardiovascular Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Stephen L Wasmund
- Division of Cardiovascular Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Richard L Page
- Division of Cardiovascular Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Mohamed H Hamdan
- Division of Cardiovascular Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
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Chaddha A, Rafanelli M, Brignole M, Sutton R, Wenzke KE, Wasmund SL, Page RL, Hamdan MH. The pathophysiologic mechanisms associated with hypotensive susceptibility. Clin Auton Res 2016; 26:261-8. [PMID: 27324399 DOI: 10.1007/s10286-016-0362-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 05/13/2016] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Patients with vasovagal syncope (VVS) and positive tilt table test (TTT) were not found to benefit from pacing in the ISSUE-3 trial despite the presence of spontaneous asystole during monitoring. "Hypotensive susceptibility" unmasked by TTT was reported as a possible explanation. The purpose of this study was to assess the pathophysiologic mechanisms associated with hypotensive susceptibility. METHODS 366 consecutive patients with the diagnosis of VVS who also had TTT were identified. Baroreflex gain (BRG) in addition to blood pressure (BP) and heart rate (HR) responses during the first 20 min of TTT were analyzed and compared between patients with positive TTT (n = 275, 75 %) and negative TTT (n = 91, 25 %). RESULTS The mean BRG was similar between the groups (12.5 ± 6.3 versus 12.4 ± 6.3 ms/mmHg, p = 0.72); however, an age-dependent decrease was noted (17.6 ± 4.8, 15.0 ± 6.0, 10.6 ± 4.2, 10.3 ± 6.4 and 9.9 ± 8.5 ms/mmHg for patients <21, 21-40, 41-60, 61-80 and >80 years old, respectively; p < 0.001). In addition, we saw a main effect of age on the type of response with a greater prevalence of a vasodepressor response in older subjects (p < 0.001). During the first 20 min of TTT, BP was similar in patients with tilt-positive VVS when compared with patients with tilt-negative VVS; however, HR was significantly lower. CONCLUSION BRG is similar in tilt-positive VVS patients when compared with tilt-negative VVS patients. An age-dependent decrease in BRG was noted with a higher prevalence of a vasodepressor response seen in older patients. The clinical significance of the blunted HR response in tilt-positive VVS remains to be determined.
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Affiliation(s)
- Ashish Chaddha
- Division of Cardiovascular Medicine, School of Medicine and Public Health, University of Wisconsin, H4/534 Clinical Science Center, 600 Highland Avenue, Madison, WI, 53792-3248, USA
| | - Martina Rafanelli
- Geriatric Cardiology and Medicine, University of Florence and Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | | | - Richard Sutton
- National Heart and Lung Institute, Imperial College, London, UK
| | - Kevin E Wenzke
- Division of Cardiovascular Medicine, School of Medicine and Public Health, University of Wisconsin, H4/534 Clinical Science Center, 600 Highland Avenue, Madison, WI, 53792-3248, USA
| | - Stephen L Wasmund
- Division of Cardiovascular Medicine, School of Medicine and Public Health, University of Wisconsin, H4/534 Clinical Science Center, 600 Highland Avenue, Madison, WI, 53792-3248, USA
| | - Richard L Page
- Division of Cardiovascular Medicine, School of Medicine and Public Health, University of Wisconsin, H4/534 Clinical Science Center, 600 Highland Avenue, Madison, WI, 53792-3248, USA
| | - Mohamed H Hamdan
- Division of Cardiovascular Medicine, School of Medicine and Public Health, University of Wisconsin, H4/534 Clinical Science Center, 600 Highland Avenue, Madison, WI, 53792-3248, USA.
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Raphan T, Cohen B, Xiang Y, Yakushin SB. A Model of Blood Pressure, Heart Rate, and Vaso-Vagal Responses Produced by Vestibulo-Sympathetic Activation. Front Neurosci 2016; 10:96. [PMID: 27065779 PMCID: PMC4814511 DOI: 10.3389/fnins.2016.00096] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 02/26/2016] [Indexed: 12/17/2022] Open
Abstract
Blood Pressure (BP), comprised of recurrent systoles and diastoles, is controlled by central mechanisms to maintain blood flow. Periodic behavior of BP was modeled to study how peak amplitudes and frequencies of the systoles are modulated by vestibular activation. The model was implemented as a relaxation oscillator, driven by a central signal related to Desired BP. Relaxation oscillations were maintained by a second order system comprising two integrators and a threshold element in the feedback loop. The output signal related to BP was generated as a nonlinear function of the derivative of the first state variable, which is a summation of an input related to Desired BP, feedback from the states, and an input from the vestibular system into one of the feedback loops. This nonlinear function was structured to best simulate the shapes of systoles and diastoles, the relationship between BP and Heart Rate (HR) as well as the amplitude modulations of BP and Pulse Pressure. Increases in threshold in one of the feedback loops produced lower frequencies of HR, but generated large pulse pressures to maintain orthostasis, without generating a VasoVagal Response (VVR). Pulse pressures were considerably smaller in the anesthetized rats than during the simulations, but simulated pulse pressures were lowered by including saturation in the feedback loop. Stochastic changes in threshold maintained the compensatory Baroreflex Sensitivity. Sudden decreases in Desired BP elicited non-compensatory VVRs with smaller pulse pressures, consistent with experimental data. The model suggests that the Vestibular Sympathetic Reflex (VSR) modulates BP and HR of an oscillating system by manipulating parameters of the baroreflex feedback and the signals that maintain the oscillations. It also shows that a VVR is generated when the vestibular input triggers a marked reduction in Desired BP.
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Affiliation(s)
- Theodore Raphan
- Department of Computer and Information Science, Institute for Neural and Intelligent Systems, Brooklyn College, City University of New York New York, NY, USA
| | - Bernard Cohen
- Department of Neurology, Icahn School of Medicine at Mount Sinai New York, NY, USA
| | - Yongqing Xiang
- Department of Computer and Information Science, Institute for Neural and Intelligent Systems, Brooklyn College, City University of New York New York, NY, USA
| | - Sergei B Yakushin
- Department of Neurology, Icahn School of Medicine at Mount Sinai New York, NY, USA
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Chun KJ, Yim HR, Park J, Park SJ, Park KM, On YK, Kim JS. Role of Baroreflex Sensitivity in Predicting Tilt Training Response in Patients with Neurally Mediated Syncope. Yonsei Med J 2016; 57:313-20. [PMID: 26847281 PMCID: PMC4740521 DOI: 10.3349/ymj.2016.57.2.313] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 06/29/2015] [Accepted: 08/10/2015] [Indexed: 12/02/2022] Open
Abstract
PURPOSE An association between baroreflex sensitivity (BRS) and the response to tilt training has not been reported in patients with neurally mediated syncope (NMS). This study sought to investigate the role of BRS in predicting the response to tilt training in patients with NMS. MATERIALS AND METHODS We analyzed 57 patients who underwent tilt training at our hospital. A responder to tilt training was defined as a patient with three consecutive negative responses to the head-up tilt test (HUT) during tilt training. RESULTS After tilt training, 52 patients (91.2%) achieved three consecutive negative responses to the HUT. In the supine position before upright posture during the first session of tilt training for responders and non-responders, the mean BRS was 18.17 ± 10.09 ms/mm Hg and 7.99 ± 5.84 ms/mm Hg (p=0.008), respectively, and the frequency of BRS ≥ 8.945 ms/mm Hg was 45 (86.5%) and 1 (20.0%; p=0.004), respectively. Age, male gender, frequency of syncopal events before HUT, type of NMS, phase of positive HUT, total number of tilt training sessions, and mean time of tilt training did not differ between the study groups. In the multivariate analysis, BRS <8.945 ms/mm Hg in the supine position (odds ratio 23.10; 95% CI 1.20-443.59; p=0.037) was significantly and independently associated with non-response to tilt training. CONCLUSION The BRS value in the supine position could be a predictor for determining the response to tilt training in patients with NMS who are being considered for inpatient tilt training.
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Affiliation(s)
- Kwang Jin Chun
- Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hye Ran Yim
- Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jungwae Park
- Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Seung Jung Park
- Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kyoung Min Park
- Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Young Keun On
- Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - June Soo Kim
- Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
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Marchi A, Bari V, De Maria B, Cerutti S, Heusser K, Tank J, Jordan J, Barbic F, Furlan R, Porta A. Evaluation of the correlation between cardiac and sympathetic baroreflex sensitivity before orthostatic syncope. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:2063-6. [PMID: 26736693 DOI: 10.1109/embc.2015.7318793] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The study investigates the two different aspects of the baroreflex control resulting in two baroreflex sensitivity (BRS) indexes: i) sympathetic BRS (sBRS); ii) cardiac BRS (cBRS). sBRS was assessed as the slope of the regression line of the conditional probability of detecting a burst on the integrated muscle nerve sympathetic activity (MSNA) given an assigned diastolic arterial pressure (DAP) on DAP. cBRS was estimated from spontaneous heart period (HP) and systolic arterial pressure (SAP) via a spectral approach in the low (0.04-0-15 Hz) and high (0.15-0.5 Hz) frequency bands respectively. Both sBRS and cBRS were assessed in eight healthy subjects undergoing three experimental sessions: supine resting position (REST), 80 degrees head-up tilt test (TILT) and before the occurrence of pre-syncope symptoms (TILT_PRE). Results showed a decrease of both sBRS and cBRS during TILT and a baroreflex impairment during TILT_PRE. sBRS and cBRS were linearly correlated during TILT but became uncorrelated during TILT_PRE. Findings suggest a failure of both "baroreflexes" and their disassociation during TILT_PRE.
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Skoog J, Lindenberger M, Ekman M, Holmberg B, Zachrisson H, Länne T. Reduced venous compliance: an important determinant for orthostatic intolerance in women with vasovagal syncope. Am J Physiol Regul Integr Comp Physiol 2015; 310:R253-61. [PMID: 26561647 DOI: 10.1152/ajpregu.00362.2015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 11/09/2015] [Indexed: 11/22/2022]
Abstract
The influence of lower limb venous compliance on orthostatic vasovagal syncope (VVS) is uncertain. The most widespread technique to calculate venous compliance uses a nonphysiological quadratic regression equation. Our aim was therefore to construct a physiologically derived venous wall model (VWM) for calculation of calf venous compliance and to determine the effect of venous compliance on tolerance to maximal lower body negative pressure (LBNP). Venous occlusion plethysmography was used to study calf volume changes in 15 women with VVS (25.5 ± 1.3 yr of age) and 15 controls (22.8 ± 0.8 yr of age). The fit of the VWM and the regression equation to the experimentally induced pressure-volume curve was examined. Venous compliance was calculated as the derivative of the modeled pressure-volume relationship. Graded LBNP to presyncope was used to determine the LBNP tolerance index (LTI). The VWM displayed a better fit to the experimentally induced pressure-volume curve (P < 0.0001). Calf blood pooling was similar in the groups and was not correlated to the LTI (r = 0.204, P = 0.30). Venous compliance was significantly reduced at low venous pressures in women with VVS (P = 0.042) and correlated to the LTI (r = 0.459, P = 0.014) in the low pressure range. No correlation was found between venous compliance at high venous pressures and the LTI. In conclusion, the new VWM accurately adopted the curvilinear pressure-volume curve, providing a valid characterization of venous compliance. Reduced venous compliance at low venous pressures may adversely affect mobilization of peripheral venous blood to the central circulation during hypovolemic circulatory stress in women with VVS.
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Affiliation(s)
- Johan Skoog
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden;
| | - Marcus Lindenberger
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden; Department of Cardiology, Linköping University, Linköping, Sweden
| | | | - Bengt Holmberg
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden; Department of Clinical Physiology, Linköping University, Linköping, Sweden; and
| | - Helene Zachrisson
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden; Department of Clinical Physiology, Linköping University, Linköping, Sweden; and
| | - Toste Länne
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden; Department of Thoracic and Vascular Surgery, Linköping University, Linköping, Sweden
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Klemenc M, Štrumbelj E. Predicting the outcome of head-up tilt test using heart rate variability and baroreflex sensitivity parameters in patients with vasovagal syncope. Clin Auton Res 2015; 25:391-8. [PMID: 26546357 DOI: 10.1007/s10286-015-0318-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 09/18/2015] [Indexed: 11/25/2022]
Abstract
PURPOSE The aim of the study was to investigate whether a statistical model could be used for an early prediction of the head-up tilt test (HUTT) outcome from heart rate variability (HRV) and baroreflex sensitivity (BRS) data obtained during early stages of the HUTT. METHODS A modified Italian protocol was used for HUTT in 105 patients with a previous history of vasovagal syncope. Beat-to-beat heart rate and blood pressure were continuously recorded. Fast Fourier transformation was used for spectral analysis of HRV and a sequence technique for measuring the BRS. RESULTS Linear statistical models based on HRV and BRS data from the first 15 min of HUTT were no more accurate than always naively predicted majority class that a syncope will occur (average model out-of-sample accuracy 56.2 ± 5.1 % vs. majority class relative frequency 54.2 %). Even when HRV and BRS data from the first 30 min were used in the model, we did not obtain any predictions of meaningful practical value (75.0 ± 5.1 % accuracy vs. 72.2 % majority class). CONCLUSIONS While there are discernible and meaningful differences between HUTT-P and HUTT-N subjects, they are not sufficient to discriminate between the two groups and predict a syncope early in the HUTT. The results might improve with a larger set of subjects; however, we can conclude that it is not likely that syncope predictions of practical value can be obtained from aggregate HRV spectral analysis and BRS values.
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Affiliation(s)
- Matjaž Klemenc
- Department of Cardiology, General Hospital of Nova Gorica, Padlih borcev 13a, 5290, Šempeter Pri Gorici, Slovenia.
| | - Erik Štrumbelj
- Faculty of Computer Science, University of Ljubljana, Večna pot 113, 1000, Ljubljana, Slovenia
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Frequent neurally mediated reflex syncope in a young patient with dextrocardia: Efficacy of catheter ablation of the superior vena cava-aorta ganglionated plexus. J Arrhythm 2015; 31:172-6. [PMID: 26336554 DOI: 10.1016/j.joa.2014.10.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 10/10/2014] [Accepted: 10/17/2014] [Indexed: 11/20/2022] Open
Abstract
Neurally mediated reflex syncope is the most common cause of syncope in young individuals without cardiac or neurological pathology. We report a case of successful catheter ablation in a 17-year-old male with neurally mediated syncope (NMS) of the cardioinhibitory type. The patient had dextrocardia situs inversus totalis with a mirror-image reversal of the thoracic and abdominal organs. Because he experienced multiple syncope episodes despite pharmacological intervention, we performed endocardial ablation of the superior vena cava-aorta ganglionated plexus. Shortly afterwards, his heart rate increased from 40 to 76 beats per minutes. He has not experienced syncope during the 1-year follow-up.
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ONISHI YOSHIMI, MINOURA YOSHINO, CHIBA YUTA, ONUKI TATSUYA, ITO HIROYUKI, ADACHI TARO, ASANO TAKU, KOBAYASHI YOUICHI. Daily Dysfunction of Autonomic Regulation Based on Ambulatory Blood Pressure Monitoring in Patients with Neurally Mediated Reflex Syncope. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2015; 38:997-1004. [DOI: 10.1111/pace.12661] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 05/01/2015] [Accepted: 05/08/2015] [Indexed: 11/30/2022]
Affiliation(s)
- YOSHIMI ONISHI
- Division of Cardiology, Department of Medicine; Showa University School of Medicine; Tokyo Japan
| | - YOSHINO MINOURA
- Division of Cardiology, Department of Medicine; Showa University School of Medicine; Tokyo Japan
| | - YUTA CHIBA
- Division of Cardiology, Department of Medicine; Showa University School of Medicine; Tokyo Japan
| | - TATSUYA ONUKI
- Division of Cardiology, Department of Medicine; Showa University School of Medicine; Tokyo Japan
| | - HIROYUKI ITO
- Division of Cardiology, Department of Medicine; Showa University School of Medicine; Tokyo Japan
| | - TARO ADACHI
- Division of Cardiology, Department of Medicine; Showa University School of Medicine; Tokyo Japan
| | - TAKU ASANO
- Division of Cardiology, Department of Medicine; Showa University School of Medicine; Tokyo Japan
| | - YOUICHI KOBAYASHI
- Division of Cardiology, Department of Medicine; Showa University School of Medicine; Tokyo Japan
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Sheldon RS, Grubb BP, Olshansky B, Shen WK, Calkins H, Brignole M, Raj SR, Krahn AD, Morillo CA, Stewart JM, Sutton R, Sandroni P, Friday KJ, Hachul DT, Cohen MI, Lau DH, Mayuga KA, Moak JP, Sandhu RK, Kanjwal K. 2015 heart rhythm society expert consensus statement on the diagnosis and treatment of postural tachycardia syndrome, inappropriate sinus tachycardia, and vasovagal syncope. Heart Rhythm 2015; 12:e41-63. [PMID: 25980576 DOI: 10.1016/j.hrthm.2015.03.029] [Citation(s) in RCA: 572] [Impact Index Per Article: 63.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Indexed: 01/14/2023]
Affiliation(s)
| | | | | | | | | | | | - Satish R Raj
- Libin Cardiovascular Institute of Alberta, Alberta, Canada; Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Andrew D Krahn
- Division of Cardiology, University of British Columbia, Vancouver, Canada
| | - Carlos A Morillo
- Department of Medicine, Cardiology Division, McMaster University Population Health Research Institute, Hamilton, Canada
| | | | - Richard Sutton
- National Heart and Lung Institute, Imperial College, London, United Kingdom
| | | | - Karen J Friday
- (13)Stanford University School of Medicine, Stanford, California
| | | | - Mitchell I Cohen
- Phoenix Children's Hospital, University of Arizona School of Medicine-Phoenix, Arizona Pediatric Cardiology/Mednax, Phoenix, Arizona
| | - Dennis H Lau
- Centre for Heart Rhythm Disorders, University of Adelaide; Department of Cardiology, Royal Adelaide Hospital; and South Australian Health and Medical Research Institute, Adelaide, Australia
| | | | - Jeffrey P Moak
- Children's National Medical Center, Washington, District of Columbia
| | - Roopinder K Sandhu
- University of Alberta, Department of Medicine, Division of Cardiology, Alberta, Canada
| | - Khalil Kanjwal
- Michigan Cardiovascular Institute, Central Michigan University, Saginaw, Michigan
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Barbic F, Heusser K, Marchi A, Zamunér AR, Gauger P, Tank J, Jordan J, Diedrich A, Robertson D, Dipaola F, Achenza S, Porta A, Furlan R. Cardiovascular parameters and neural sympathetic discharge variability before orthostatic syncope: role of sympathetic baroreflex control to the vessels. Physiol Meas 2015; 36:633-41. [PMID: 25798786 DOI: 10.1088/0967-3334/36/4/633] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We tested the hypothesis that altered sympathetic baroreceptor control to the vessels (svBRS) and disrupted coupling between blood pressure (BP) fluctuations and muscle sympathetic activity (MSNA) discharge pattern in the low frequency band (LF, around 0.1 Hz) precede vasovagal syncope. Seven healthy males underwent ECG, BP, respiratory, and MSNA recordings at baseline (REST) and during a 15 min 80° head-up tilt, followed by a -10 mmHg step wise increase of lower body negative pressure up to presyncope. Spectral and coherence analyses of systolic arterial pressure (SAP) and MSNA variability provided the indexes of vascular sympathetic modulation, LFSAP, and of the linear coupling between MSNA and SAP in the low frequency band (around 0.1 Hz), K(2)MSNA-SAP(LF). svBRS was assessed as the slope of the regression line between MSNA and diastolic arterial pressure (DAP). Data were analyzed at REST, during asymptomatic and presyncope periods of tilt. svBRS declined during presyncope period compared to REST and asymptomatic tilt. The presyncope period was characterized by a decrease of RR interval, LFMSNA, LFSAP, and K(2)MSNA-SAP(LF) values compared to the asymptomatic one, whereas MSNA burst rate was unchanged. The reduction of svBRS producing an altered coupling between MSNA and SAP variability at 0.1 Hz, may provoke circulatory changes leading to presyncope.
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Affiliation(s)
- Franca Barbic
- Internal Medicine, Humanitas Clinical and Research Center, Rozzano, BIOMETRA Department, University of Milan, Italy
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Goldstein DS. Concepts of scientific integrative medicine applied to the physiology and pathophysiology of catecholamine systems. Compr Physiol 2014; 3:1569-610. [PMID: 24265239 DOI: 10.1002/cphy.c130006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This review presents concepts of scientific integrative medicine and relates them to the physiology of catecholamine systems and to the pathophysiology of catecholamine-related disorders. The applications to catecholamine systems exemplify how scientific integrative medicine links systems biology with integrative physiology. Concepts of scientific integrative medicine include (i) negative feedback regulation, maintaining stability of the body's monitored variables; (ii) homeostats, which compare information about monitored variables with algorithms for responding; (iii) multiple effectors, enabling compensatory activation of alternative effectors and primitive specificity of stress response patterns; (iv) effector sharing, accounting for interactions among homeostats and phenomena such as hyperglycemia attending gastrointestinal bleeding and hyponatremia attending congestive heart failure; (v) stress, applying a definition as a state rather than as an environmental stimulus or stereotyped response; (vi) distress, using a noncircular definition that does not presume pathology; (vii) allostasis, corresponding to adaptive plasticity of feedback-regulated systems; and (viii) allostatic load, explaining chronic degenerative diseases in terms of effects of cumulative wear and tear. From computer models one can predict mathematically the effects of stress and allostatic load on the transition from wellness to symptomatic disease. The review describes acute and chronic clinical disorders involving catecholamine systems-especially Parkinson disease-and how these concepts relate to pathophysiology, early detection, and treatment and prevention strategies in the post-genome era.
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Affiliation(s)
- David S Goldstein
- Clinical Neurocardiology Section, Clinical Neurosciences Program, Division of Intramural Research, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
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Alboni P, Alboni M. Vasovagal Syncope As A Manifestation Of An Evolutionary Selected Trait. J Atr Fibrillation 2014; 7:1035. [PMID: 27957092 PMCID: PMC5135249 DOI: 10.4022/jafib.1035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 08/19/2014] [Accepted: 08/20/2014] [Indexed: 01/10/2023]
Abstract
Some observations suggest that typical (emotional or orthostatic) vasovagal syncope (VVS) is not a disease, but rather a manifestation of a non-pathological trait. We conducted an extensive bibliographic research on the vasovagal reactions in animals, including humans, in order to investigate the possible factors that may explain the origin and evolution of VVS. We found two processes which appear relevant for the investigation of VVS evolution: fear/threat bradycardia (alarm bradycardia) in animals, mainly during tonic immobility and vasovagal reflex during hemorrhagic shock (thoracic hypovolemia) both in animals and humans. The available data suggest that VVS in humans, alarm bradycardia in animals and the vasovagal reflex during hemorrhagic shock share the same physiological mechanisms and that is indicative of a common evolutionary root. However, during the vasovagal reflex loss of consciousness occurs in humans, but it is absent (or extremely rare) in animals. That can be explained as a by-product due to the erect position and the large brain evolved in our species. If the vasovagal reflex persisted for millions of years along the vertebrates evolutionary history, we can reasonably assume that it has a function and it is not harmful. It could be neutral or beneficial, but the available data suggest it is beneficial; likely, it evolved as an advantageous response to stressful and possibly dangerous heart conditions. Emotional or orthostatic vasovagal reflex is preceded by enhanced sympathetic activity, which is harmful and possibly dangerous. The transient inhibition of the sympathetic system, together with activation of the vagal tone , characterizes VVS. The consequent slowing of the heart rate induced by the vasovagal reflex may constitute a beneficial break of the cardiac pump, thereby reducing myocardial oxygen consumption. We suggest that typical VVS should be regarded as a selected response, which probably evolved in the ancient past as a defense mechanism of the organism within some ancestral group(s) of vertebrates.
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Affiliation(s)
- Paolo Alboni
- Section of Cardiology and Syncope Unit, Ospedale Privato Quisisana, Ferrara, Italy
| | - Marco Alboni
- Department of Zoology and Anthropology, University of Sassari, Italy
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Lambert E, Lambert GW. Sympathetic dysfunction in vasovagal syncope and the postural orthostatic tachycardia syndrome. Front Physiol 2014; 5:280. [PMID: 25120493 PMCID: PMC4112787 DOI: 10.3389/fphys.2014.00280] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 07/08/2014] [Indexed: 01/29/2023] Open
Abstract
Orthostatic intolerance is the inability to tolerate the upright posture and is relieved by recumbence. It most commonly affects young women and has a major impact on quality of life and psychosocial well-being. Several forms of orthostatic intolerance have been described. The most common one is the recurrent vasovagal syncope (VVS) phenotype which presents as a transient and abrupt loss of consciousness and postural tone that is followed by rapid recovery. Another common type of orthostatic intolerance is the postural orthostatic tachycardia syndrome (POTS) which is characterized by an excessive rise in heart rate upon standing and is associated with symptoms of presyncope such as light-headedness, fatigue, palpitations, and nausea. Maintenance of arterial pressure under condition of reduced central blood volume during the orthostasis is accomplished in large part through sympathetic efferent nerve traffic to the peripheral vasculature. Therefore sympathetic nervous system (SNS) dysfunction is high on the list of possible contributors to the pathophysiology of orthostatic intolerance. Investigations into the role of the SNS in orthostatic intolerance have yielded mixed results. This review outlines the current knowledge of the function of the SNS in both VVS and POTS.
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Affiliation(s)
- Elisabeth Lambert
- Human Neurotransmitters Laboratory, Baker IDI Heart and Diabetes Institute Melbourne, VIC, Australia ; Departments of Physiology, Monash University Clayton, VIC, Australia
| | - Gavin W Lambert
- Human Neurotransmitters Laboratory, Baker IDI Heart and Diabetes Institute Melbourne, VIC, Australia ; Faculty of Medicine, Nursing and Health Sciences, Monash University Clayton, VIC, Australia
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Pathophysiology of neurally mediated syncope: Role of cardiac output and total peripheral resistance. Auton Neurosci 2014; 184:24-6. [PMID: 25081417 DOI: 10.1016/j.autneu.2014.07.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 07/07/2014] [Accepted: 07/09/2014] [Indexed: 11/24/2022]
Abstract
Syncope is a common clinical condition occurring even in otherwise healthy people without underlying cardiovascular disease. Neurally mediated syncope is by far the most common cause of syncope in individuals without any structural heart disease. Based on traditional wisdom, loss of sympathetic tone with relaxation of vascular smooth muscle is the key mechanism underlying the pathophysiology of syncope, especially in patients without an acute decrease in heart rate. However, this concept has recently been challenged. Some microneurographic studies indicate that sympathetic withdrawal may not always be a prerequisite even for the development of classic "vasodepressor" forms of syncope. Conversely, a decrease in cardiac output appears to be a determinant factor for syncope in most circumstances. This article reviews the relative contribution of cardiac output versus sympathetic vasoconstriction in neurally mediated syncope in otherwise healthy individuals. It is suggested that a moderate to severe fall in cardiac output with or without vasodilatation may contribute to syncope.
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