1
|
Alsaleh M, Talati A, Raj SR, Sheldon RS. Serotonin and vasovagal syncope. Clin Auton Res 2024; 34:385-394. [PMID: 38980470 DOI: 10.1007/s10286-024-01052-1] [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: 04/04/2024] [Accepted: 06/27/2024] [Indexed: 07/10/2024]
Abstract
PURPOSE The goal of this manuscript was to review the biological and clinical evidence that serotonin neurotransmission might play an important role in the physiology and treatment of vasovagal syncope. METHODS The authors reviewed PubMed and handsearches of secondary sources for papers related to the Bezold-Jarisch reflex and serotonin, the plausible involvement of the Bezold-Jarisch reflex in vasovagal syncope, and three lines of clinical evidence involving serotonin and the syncope. RESULTS The Bezold-Jarisch reflex was first described following the infusion of veratrum alkaloids into animals in the 19th century. The reflex is triggered by serotonin stimulation chemoreceptors and mechanoreceptors in the the left ventricle. The afferent component of the reflex is carried by unmyelinated type C vagal nerve fibers, which results in parasympathetic efferent stimulation that causes bradycardia. The similarity of the combination of hypotension and bradycardia in the Bezold-Jarisch reflex and in vasovagal syncope led to the suggestion that the reflex was the cause of the syndrome. Three lines of evidence implicate the serotonin 5HT3 receptors in the heart in the reflex. There is genetic and physiologic evidence for the serotonin 5HT1A and 5HT3 receptors and the serotonin reuptake transporter (SERT). Acute blockade of SERT induces vasovagal syncope in humans undergoing head-up tilt table testing, and SERT inhibition reduces hypotension and bradycardia during spinal anaesthesia. Finally, three randomized clinical trials of SERT inhibitors uniformly reported that they significantly reduce the likelihood of vasovagal syncope recurrences. CONCLUSION Multiple lines of evidence implicate serotonin neurotransmission in the cause of vasovagal syncope.
Collapse
Affiliation(s)
- Mohammed Alsaleh
- Department of Cardiac Sciences, Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, GAA04 HRIC Building 3280 Hospital Drive Calgary, Calgary, AB, T2N 4Z6, Canada
| | - Aryan Talati
- Department of Cardiac Sciences, Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, GAA04 HRIC Building 3280 Hospital Drive Calgary, Calgary, AB, T2N 4Z6, Canada
| | - Satish R Raj
- Department of Cardiac Sciences, Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, GAA04 HRIC Building 3280 Hospital Drive Calgary, Calgary, AB, T2N 4Z6, Canada
| | - Robert S Sheldon
- Department of Cardiac Sciences, Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, GAA04 HRIC Building 3280 Hospital Drive Calgary, Calgary, AB, T2N 4Z6, Canada.
| |
Collapse
|
2
|
Raj P, Lei L, Flevaris P, Raj S, Sheldon R. Serotonin reuptake inhibition for the prevention of vasovagal syncope: a systematic review and meta-analysis. Clin Auton Res 2023; 33:811-819. [PMID: 37971641 DOI: 10.1007/s10286-023-01000-5] [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: 09/12/2023] [Accepted: 10/28/2023] [Indexed: 11/19/2023]
Abstract
PURPOSE Vasovagal syncope is a common clinical condition that lacks effective medical therapies despite being associated with significant morbidity. Current guidelines suggest that serotonin-specific reuptake inhibitors might suppress vasovagal syncope but supporting studies have been small and heterogenous. The purpose of this study was to evaluate the efficacy of serotonin-specific reuptake inhibitors to prevent syncope in patients with recurrent vasovagal syncope by conducting a systematic review and meta-analysis of published studies. METHODS Relevant randomized controlled trials were identified from the MEDLINE and Embase databases without language restriction from inception to August 2022, and ClinicalTrials.gov. All studies were conducted in clinical syncope populations and compared the benefit of serotonin versus placebo. Weighted relative risks were estimated using random effects meta-analysis techniques. RESULTS Three studies (n = 204) met inclusion criteria. Patients were 42 ± 13 years of age and 51% female. Serotonin-specific reuptake inhibitors were found to substantially reduce the likelihood of a patient having at least one recurrence of vasovagal syncope [relative risk (RR) 0.34 (0.20-0.60), p < 0.01] with minimal between-study heterogeneity (I2 = 0%, p = 0.67). Serotonin-specific reuptake inhibitors in two reports provided significant protection against clinical presyncope [RR 0.43 (0.24-0.77), p < 0.01], with minimal between-study heterogeneity (I2 = 0%, p = 0.80). CONCLUSIONS Serotonin-specific reuptake inhibitors may be effective in preventing syncope induced by head-up tilt testing and in syncope in the community in randomized, double-blinded clinical trials.
Collapse
Affiliation(s)
- Priya Raj
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, GAA02 HRIC Building, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada
| | - Lucy Lei
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, GAA02 HRIC Building, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada
| | - Panagiota Flevaris
- 2nd Department of Cardiology, Attikon University Hospital, Athens, Greece
| | - Satish Raj
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, GAA02 HRIC Building, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada
| | - Robert Sheldon
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, GAA02 HRIC Building, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada.
| |
Collapse
|
3
|
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.
Collapse
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.
| |
Collapse
|
4
|
Sandhu RK, Raj SR, Hamzeh R, Sheldon RS. The Seventh Prevention of Syncope Trial (POST VII)-A randomized clinical trial of atomoxetine for the prevention of vasovagal syncope: Rationale and study design. Am Heart J 2023; 262:49-54. [PMID: 37100187 DOI: 10.1016/j.ahj.2023.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 03/30/2023] [Accepted: 04/18/2023] [Indexed: 05/14/2023]
Abstract
BACKGROUND Vasovagal syncope (VVS) is common, recurs, and is associated with markedly reduced quality of life, anxiety, and frequent injuries. The few pharmacological therapies for VVS proven to have a moderate benefit in reducing recurrences are limited to patients without coexisting conditions such as hypertension or heart failure. Although there is some data to suggest Atomoxetine, a norepinephrine reuptake transport inhibitor (NET), may be a promising treatment option, an adequately powered randomized placebo-controlled trial is needed. STUDY DESIGN POST VII is a multicenter, randomized, double-blind, placebo-controlled, crossover study that will randomize 180 patients with VVS and at least 2 syncopal spells in the preceding year to a target daily dose of atomoxetine 80 mg daily or to a matching placebo, with an observation period of 6 months in each phase and with a 1-week washout period between phases. The primary end point will be the proportion of patients with at least one syncope recurrence in each arm analyzed with an intention-to-treat approach. The secondary end points include total syncope burden, quality of life, cost, and cost-effectiveness. POWER CALCULATIONS Assuming a 33% relative risk reduction in syncope recurrence with atomoxetine, and a dropout rate of 16%, the enrollment of 180 patients will give an 85% power of reaching a positive conclusion about atomoxetine, with P = .05. CONCLUSIONS This will be the first adequately powered trial to determine whether atomoxetine is effective in preventing VVS. If proven effective, atomoxetine might become the first-line pharmacological treatment for recurrent VVS.
Collapse
Affiliation(s)
- Roopinder K Sandhu
- Smidt Heart Institute, Cedars-Sinai Hospital, Los Angeles, CA; Division of Cardiology, University of Alberta, Edmonton, Alberta, Canada.
| | - Satish R Raj
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Rasha Hamzeh
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Robert S Sheldon
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| |
Collapse
|
5
|
Sheldon RS, Gerull B. Have we found the genetic signature for vasovagal syncope? Eur Heart J 2023; 44:1081-1083. [PMID: 36734005 DOI: 10.1093/eurheartj/ehac821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Affiliation(s)
- Robert S Sheldon
- Libin Cardiovascular Institute, University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4N1, Canada
| | - Brenda Gerull
- Department of Internal Medicine I and Comprehensive Heart Failure Center at the University of Würzburg, Würzburg, Germany
| |
Collapse
|
6
|
Aegisdottir HM, Thorolfsdottir RB, Sveinbjornsson G, Stefansson OA, Gunnarsson B, Tragante V, Thorleifsson G, Stefansdottir L, Thorgeirsson TE, Ferkingstad E, Sulem P, Norddahl G, Rutsdottir G, Banasik K, Christensen AH, Mikkelsen C, Pedersen OB, Brunak S, Bruun MT, Erikstrup C, Jacobsen RL, Nielsen KR, Sørensen E, Frigge ML, Hjorleifsson KE, Ivarsdottir EV, Helgadottir A, Gretarsdottir S, Steinthorsdottir V, Oddsson A, Eggertsson HP, Halldorsson GH, Jones DA, Anderson JL, Knowlton KU, Nadauld LD, Haraldsson M, Thorgeirsson G, Bundgaard H, Arnar DO, Thorsteinsdottir U, Gudbjartsson DF, Ostrowski SR, Holm H, Stefansson K. Genetic variants associated with syncope implicate neural and autonomic processes. Eur Heart J 2023; 44:1070-1080. [PMID: 36747475 DOI: 10.1093/eurheartj/ehad016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 11/22/2022] [Accepted: 01/05/2023] [Indexed: 02/08/2023] Open
Abstract
AIMS Syncope is a common and clinically challenging condition. In this study, the genetics of syncope were investigated to seek knowledge about its pathophysiology and prognostic implications. METHODS AND RESULTS This genome-wide association meta-analysis included 56 071 syncope cases and 890 790 controls from deCODE genetics (Iceland), UK Biobank (United Kingdom), and Copenhagen Hospital Biobank Cardiovascular Study/Danish Blood Donor Study (Denmark), with a follow-up assessment of variants in 22 412 cases and 286 003 controls from Intermountain (Utah, USA) and FinnGen (Finland). The study yielded 18 independent syncope variants, 17 of which were novel. One of the variants, p.Ser140Thr in PTPRN2, affected syncope only when maternally inherited. Another variant associated with a vasovagal reaction during blood donation and five others with heart rate and/or blood pressure regulation, with variable directions of effects. None of the 18 associations could be attributed to cardiovascular or other disorders. Annotation with regard to regulatory elements indicated that the syncope variants were preferentially located in neural-specific regulatory regions. Mendelian randomization analysis supported a causal effect of coronary artery disease on syncope. A polygenic score (PGS) for syncope captured genetic correlation with cardiovascular disorders, diabetes, depression, and shortened lifespan. However, a score based solely on the 18 syncope variants performed similarly to the PGS in detecting syncope risk but did not associate with other disorders. CONCLUSION The results demonstrate that syncope has a distinct genetic architecture that implicates neural regulatory processes and a complex relationship with heart rate and blood pressure regulation. A shared genetic background with poor cardiovascular health was observed, supporting the importance of a thorough assessment of individuals presenting with syncope.
Collapse
Affiliation(s)
- Hildur M Aegisdottir
- deCODE genetics/Amgen, Inc., Sturlugata 8, Reykjavik 101, Iceland
- Faculty of Medicine, University of Iceland, Vatnsmyrarvegur 16, Reykjavik 101, Iceland
| | | | | | | | | | | | | | | | | | - Egil Ferkingstad
- deCODE genetics/Amgen, Inc., Sturlugata 8, Reykjavik 101, Iceland
| | - Patrick Sulem
- deCODE genetics/Amgen, Inc., Sturlugata 8, Reykjavik 101, Iceland
| | | | | | - Karina Banasik
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3A, Copenhagen 2200, Denmark
| | - Alex Hoerby Christensen
- The Unit for Inherited Cardiac Diseases, Department of Cardiology, The Heart Centre, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9, Copenhagen 2100, Denmark
- Department of Cardiology, Herlev-Gentofte Hospital, Copenhagen University Hospital, Borgmester Ib Juuls Vej 1, Herlev 2730, Denmark
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, Copenhagen 2200, Denmark
| | - Christina Mikkelsen
- Department of Clinical Immunology, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9, Copenhagen 2100, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Blegdamsvej 3A, Copenhagen 2200, Denmark
| | - Ole Birger Pedersen
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, Copenhagen 2200, Denmark
- Department of Clinical Immunology, Zealand University Hospital - Køge, Lykkebækvej 1, Køge 4600, Denmark
| | - Søren Brunak
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3A, Copenhagen 2200, Denmark
| | - Mie Topholm Bruun
- Department of Clinical Immunology, Odense University Hospital, J. B. Winsløws Vej 4, Odense 5000, Denmark
| | - Christian Erikstrup
- Department of Clinical Immunology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, Aarhus 8200, Denmark
- Department of Clinical Medicine, Aarhus University, Nordre Ringgade 1, Aarhus 8000, Denmark
| | - Rikke Louise Jacobsen
- Department of Clinical Immunology, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9, Copenhagen 2100, Denmark
| | - Kaspar Rene Nielsen
- Department of Clinical Immunology, Aalborg University Hospital, Urbansgade 32, Aalborg 9000, Denmark
| | - Erik Sørensen
- Department of Clinical Immunology, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9, Copenhagen 2100, Denmark
| | - Michael L Frigge
- deCODE genetics/Amgen, Inc., Sturlugata 8, Reykjavik 101, Iceland
| | | | | | - Anna Helgadottir
- deCODE genetics/Amgen, Inc., Sturlugata 8, Reykjavik 101, Iceland
| | | | | | - Asmundur Oddsson
- deCODE genetics/Amgen, Inc., Sturlugata 8, Reykjavik 101, Iceland
| | | | | | - David A Jones
- Precision Genomics, Intermountain Healthcare, 600 S. Medical Center Drive, Saint George, UT 84790, USA
| | - Jeffrey L Anderson
- Intermountain Medical Center, Intermountain Heart Institute, 5171 S. Cottonwood Street Building 1, Salt Lake City, UT 84107, USA
- Department of Internal Medicine, University of Utah, 30 N 1900 E, Salt Lake City, UT 84132, USA
| | - Kirk U Knowlton
- Intermountain Medical Center, Intermountain Heart Institute, 5171 S. Cottonwood Street Building 1, Salt Lake City, UT 84107, USA
- School of Medicine, University of Utah, 30 N 1900 E, Salt Lake City, UT 84132, USA
| | - Lincoln D Nadauld
- Precision Genomics, Intermountain Healthcare, 600 S. Medical Center Drive, Saint George, UT 84790, USA
- School of Medicine, Stanford University, 291 Campus Drive, Stanford, CA 94305, USA
| | | | - Magnus Haraldsson
- Faculty of Medicine, University of Iceland, Vatnsmyrarvegur 16, Reykjavik 101, Iceland
- Department of Psychiatry, Landspitali, The National University Hospital of Iceland, Hringbraut, Reykjavik 101, Iceland
| | - Gudmundur Thorgeirsson
- deCODE genetics/Amgen, Inc., Sturlugata 8, Reykjavik 101, Iceland
- Faculty of Medicine, University of Iceland, Vatnsmyrarvegur 16, Reykjavik 101, Iceland
- Department of Medicine, Landspitali, The National University Hospital of Iceland, Hringbraut, Reykjavik 101, Iceland
| | - Henning Bundgaard
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, Copenhagen 2200, Denmark
- The Capital Regions Unit for Inherited Cardiac Diseases, Department of Cardiology, The Heart Centre, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9, Copenhagen 2100, Denmark
| | - David O Arnar
- deCODE genetics/Amgen, Inc., Sturlugata 8, Reykjavik 101, Iceland
- Faculty of Medicine, University of Iceland, Vatnsmyrarvegur 16, Reykjavik 101, Iceland
- Department of Medicine, Landspitali, The National University Hospital of Iceland, Hringbraut, Reykjavik 101, Iceland
| | - Unnur Thorsteinsdottir
- deCODE genetics/Amgen, Inc., Sturlugata 8, Reykjavik 101, Iceland
- Faculty of Medicine, University of Iceland, Vatnsmyrarvegur 16, Reykjavik 101, Iceland
| | - Daniel F Gudbjartsson
- deCODE genetics/Amgen, Inc., Sturlugata 8, Reykjavik 101, Iceland
- School of Engineering and Natural Sciences, University of Iceland, Hjardarhagi 4, Reykjavik 107, Iceland
| | - Sisse R Ostrowski
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, Copenhagen 2200, Denmark
- Department of Clinical Immunology, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9, Copenhagen 2100, Denmark
| | - Hilma Holm
- deCODE genetics/Amgen, Inc., Sturlugata 8, Reykjavik 101, Iceland
| | - Kari Stefansson
- deCODE genetics/Amgen, Inc., Sturlugata 8, Reykjavik 101, Iceland
- Faculty of Medicine, University of Iceland, Vatnsmyrarvegur 16, Reykjavik 101, Iceland
| |
Collapse
|
7
|
Sheldon RS, Seifer C, Parkash R, Sandhu RK, Hamzeh R, Raj SR. Atomoxetine for suppression of vasovagal syncope. Clin Auton Res 2023; 33:23-28. [PMID: 36401665 DOI: 10.1007/s10286-022-00905-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 10/26/2022] [Indexed: 11/21/2022]
Abstract
OBJECTIVE Vasovagal syncope (VVS) is a common clinical condition with few effective medical therapies. The study aimed to evaluate the effectiveness of atomoxetine in suppressing syncope in patients with recurrent VVS. METHODS This was a retrospective, open-label, observational case series of 12 patients taking atomoxetine for suppression of recurrent vasovagal syncope. We compared syncope frequency in the 1 year before atomoxetine and while subjects were taking atomoxetine. We used novel applications of the Poisson distribution to describe the results as a collection of n = 1 studies. RESULTS There were 12 subjects, eight female, with a mean age 47 ± 22 years and a mean Calgary Syncope Symptom Score of 2 (diagnostic of vasovagal syncope). The patients received a mean dose of atomoxetine of 66 ± 16 mg (1.06 ± 0.21 mg/kg). The mean follow-up period was 1.21 ± 1.01 years. While taking atomoxetine, 11/12 patients appeared to improve and 7/12 had no syncope in follow-up (p = 0.0046). The annualized syncope frequency decreased from a median 5.5 (IQR 4, 6.75) syncope per year to 0 (IQR 0, 0.88) syncope per year (p = 0.002, Wilcoxon rank-sum test). According to the Poisson distribution, 7/12 subjects significantly improved with p values of < 0.0001 to 0.0235, 3/12 did not faint but had too brief follow-up times to detect significance, and 2/12 did not improve significantly. CONCLUSIONS In this case series, atomoxetine was a promising oral agent for the prevention of vasovagal syncope. The Poisson distribution permits individual patient-level assessment of improvement and detects insufficient follow-up despite apparent improvement.
Collapse
Affiliation(s)
- Robert S Sheldon
- Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, GAA02 HRIC Building, 3280 Hospital Drive NW AB, Calgary, T2N 4Z6, Canada.
| | - Colette Seifer
- Cardiac Sciences Programme, University of Manitoba, Winnipeg, Canada
| | - Ratika Parkash
- Department of Medicine, Dalhousie University, Halifax, Canada
| | - Roopinder K Sandhu
- Cedars-Sinai Medical Center, Smidt Heart Institute, Los Angeles, California, USA
| | - Rasha Hamzeh
- Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, GAA02 HRIC Building, 3280 Hospital Drive NW AB, Calgary, T2N 4Z6, Canada
| | - Satish R Raj
- Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, GAA02 HRIC Building, 3280 Hospital Drive NW AB, Calgary, T2N 4Z6, Canada
| |
Collapse
|
8
|
Hatoum T, Raj S, Sheldon RS. Current approach to the treatment of vasovagal syncope in adults. Intern Emerg Med 2023; 18:23-30. [PMID: 36117230 DOI: 10.1007/s11739-022-03102-w] [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: 08/10/2022] [Accepted: 09/05/2022] [Indexed: 02/01/2023]
Abstract
Vasovagal syncope (VVS) is the most common cause of transient loss of consciousness. Although not associated with mortality, it causes injuries, reduces quality of life, and is associated with anxiety and depression. The European and North American cardiac societies recently published syncope clinical practice guidelines. Most patients with VVS do well after specialist evaluation, reassurance and education. Adequate hydration, increased salt intake when not contraindicated, and careful withdrawal of diuretics and specific hypotension-inducing drugs are a reasonable initial strategy. Physical counterpressure maneuvers might be helpful but can be of limited efficacy in older patients and those with short or no prodromes. Orthostatic training lacks long term efficacy and is troubled by non-compliance. Yoga might be helpful, although the biomedical mechanism is unknown. Almost a third of VVS patients continue to faint despite these conservative measures. Metoprolol was not helpful in a pivotal randomized clinical trial. Fludrocortisone and midodrine significantly reduce syncope recurrences with tolerable side effects, when titrated to target doses. Pacing therapy with specialized sensors appears promising in carefully selected population who have not responded conservative measures. Cardioneuroablation may be helpful but has not been studied in a formal clinical trial.
Collapse
Affiliation(s)
- Tarek Hatoum
- Libin Cardiovascular Institute, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Satish Raj
- Libin Cardiovascular Institute, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Robert Stanley Sheldon
- Libin Cardiovascular Institute, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.
| |
Collapse
|
9
|
Sheldon RS, Raj SR. Treating Syncope Without Drugs: Standing Still, Exercising Hard, or Simply the “Expert's Touch”? J Cardiovasc Electrophysiol 2022; 33:1871-1873. [DOI: 10.1111/jce.15576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 05/26/2022] [Indexed: 11/26/2022]
Affiliation(s)
- Robert S Sheldon
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of MedicineUniversity of CalgaryCalgaryABCanada
| | - Satish R Raj
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of MedicineUniversity of CalgaryCalgaryABCanada
| |
Collapse
|
10
|
Sutton R, Ricci F, Fedorowski A. Risk stratification of syncope: Current syncope guidelines and beyond. Auton Neurosci 2022; 238:102929. [PMID: 34968831 DOI: 10.1016/j.autneu.2021.102929] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 11/27/2021] [Accepted: 12/08/2021] [Indexed: 11/28/2022]
Abstract
Syncope is an alarming event carrying the possibility of serious outcomes, including sudden cardiac death (SCD). Therefore, immediate risk stratification should be applied whenever syncope occurs, especially in the Emergency Department, where most dramatic presentations occur. It has long been known that short- and long-term syncope prognosis is affected not only by its mechanism but also by presence of concomitant conditions, especially cardiovascular disease. Over the last two decades, several syncope prediction tools have been developed to refine patient stratification and triage patients who need expert in-hospital care from those who may receive nonurgent expert care in the community. However, despite promising results, prognostic tools for syncope remain challenging and often poorly effective. Current European Society of Cardiology syncope guidelines recommend an initial syncope workup based on detailed patient's history, physical examination supine and standing blood pressure, resting ECG, and laboratory tests, including cardiac biomarkers, where appropriate. Subsequent risk stratification based on screening of features aims to identify three groups: high-, intermediate- and low-risk. The first should immediately be hospitalized and appropriately investigated; intermediate group, with recurrent or medium-risk events, requires systematic evaluation by syncope experts; low-risk group, sporadic reflex syncope, merits education about its benign nature, and discharge. Thus, initial syncope risk stratification is crucial as it determines how and by whom syncope patients are managed. This review summarizes the crucial elements of syncope risk stratification, pros and cons of proposed risk evaluation scores, major challenges in initial syncope management, and how risk stratification impacts management of high-risk/recurrent syncope.
Collapse
Affiliation(s)
- Richard Sutton
- National Heart & Lung Institute, Imperial College, Dept. of Cardiology, Hammersmith Hospital, Du Cane Road, London W12 0HS, United Kingdom
| | - Fabrizio Ricci
- Department of Neuroscience, Imaging and Clinical Sciences, "G.d'Annunzio" University of Chieti-Pescara, Via Luigi Polacchi, 11, 66100 Chieti, Italy; Casa di Cura Villa Serena, Città Sant'Angelo, Italy
| | - Artur Fedorowski
- Dept. of Cardiology, Karolinska University Hospital, and Department of Medicine, Karolinska Institute, Stockholm, Sweden.
| |
Collapse
|
11
|
Matveeva N, Titov B, Bazyleva E, Pevzner A, Favorova O. Towards Understanding the Genetic Nature of Vasovagal Syncope. Int J Mol Sci 2021; 22:10316. [PMID: 34638656 PMCID: PMC8508958 DOI: 10.3390/ijms221910316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 11/17/2022] Open
Abstract
Syncope, defined as a transient loss of consciousness caused by transient global cerebral hypoperfusion, affects 30-40% of humans during their lifetime. Vasovagal syncope (VVS) is the most common cause of syncope, the etiology of which is still unclear. This review summarizes data on the genetics of VVS, describing the inheritance pattern of the disorder, candidate gene association studies and genome-wide studies. According to this evidence, VVS is a complex disorder, which can be caused by the interplay between genetic factors, whose contribution varies from monogenic Mendelian inheritance to polygenic inherited predisposition, and external factors affecting the monogenic (resulting in incomplete penetrance) and polygenic syncope types.
Collapse
Affiliation(s)
- Natalia Matveeva
- National Medical Research Center for Cardiology, 121552 Moscow, Russia; (N.M.); (B.T.); (E.B.); (A.P.)
- Department of Molecular Biology and Medical Biotechnology, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Boris Titov
- National Medical Research Center for Cardiology, 121552 Moscow, Russia; (N.M.); (B.T.); (E.B.); (A.P.)
- Department of Molecular Biology and Medical Biotechnology, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Elizabeth Bazyleva
- National Medical Research Center for Cardiology, 121552 Moscow, Russia; (N.M.); (B.T.); (E.B.); (A.P.)
| | - Alexander Pevzner
- National Medical Research Center for Cardiology, 121552 Moscow, Russia; (N.M.); (B.T.); (E.B.); (A.P.)
| | - Olga Favorova
- National Medical Research Center for Cardiology, 121552 Moscow, Russia; (N.M.); (B.T.); (E.B.); (A.P.)
- Department of Molecular Biology and Medical Biotechnology, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| |
Collapse
|
12
|
Sheldon RS, Gerull B. Genetic markers of vasovagal syncope. Auton Neurosci 2021; 235:102871. [PMID: 34474354 DOI: 10.1016/j.autneu.2021.102871] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 08/10/2021] [Accepted: 08/22/2021] [Indexed: 12/18/2022]
Abstract
Vasovagal syncope may have a genetic predisposition. It has a high prevalence in some families, and children of a fainting parent are more likely to faint than those without a parent who faints. Having two fainting parents or a fainting twin increases the likelihood even further. Several genotypes appear to associate with the phenotype of positive tilt tests, but the control subjects are usually those who faint and have negative tilt tests. Twin studies, highly focused genome-wide association studies, and copy number variation studies all suggest there are loci in the genome that associate with vasovagal syncope, although the specific genes, pathways, and proteins are unknown. A recent multigenerational kindred candidate gene study identified 3 genes that associate with vasovagal syncope. The best evidence to date is for central signaling genes involving serotonin and dopamine. Genome-wide association studies to date have not yet been helpful. Our understanding of the genetic correlates of vasovagal syncope leaves ample opportunity for future work.
Collapse
Affiliation(s)
- Robert S Sheldon
- Libin Cardiovascular Institute, University of Calgary, Calgary, Canada; Department of Internal Medicine I and Comprehensive Heart Failure Center, University of Würzburg, Germany.
| | - Brenda Gerull
- Libin Cardiovascular Institute, University of Calgary, Calgary, Canada; Department of Internal Medicine I and Comprehensive Heart Failure Center, University of Würzburg, Germany
| |
Collapse
|
13
|
Fedorowski A, Pirouzifard M, Sundquist J, Sundquist K, Sutton R, Zöller B. Risk Factors for Syncope Associated With Multigenerational Relatives With a History of Syncope. JAMA Netw Open 2021; 4:e212521. [PMID: 33783519 PMCID: PMC8010588 DOI: 10.1001/jamanetworkopen.2021.2521] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
IMPORTANCE Reflex syncope is the major cause of transient loss of consciousness, which affects one-third of the population, but effective treatment for individuals with severe syncope is lacking. Better understanding of reflex syncope predisposition may offer new therapeutic solutions. OBJECTIVES To determine the familial risk of syncope in first-, second-, and third-degree relatives of affected individuals and to explore the role of genes and family environment in reflex syncope. DESIGN, SETTING, AND PARTICIPANTS In this national population-based family cohort study, the Swedish multigeneration register was linked to 3 Swedish nationwide registers: hospital discharge, outpatient care, and primary care registers for the period from 1997 to 2015. Sibling pairs born to Swedish parents between 1948 and 2005 were included. Linkage was also made to half-siblings and cousins. Data analysis was performed from June to October 2020. EXPOSURES Register-based syncope diagnosis among relatives: pairs of twins, siblings, half-siblings, and cousins. MAIN OUTCOMES AND MEASURES Odds ratios for syncope were calculated for relatives (twins, siblings, half-siblings, and cousins) of individuals who had syncope compared with relatives of individuals without syncope for reference. Sensitivity analysis excluding families with definite nonreflex syncope diagnosis was performed. RESULTS Among the study population of 2 694 442 participants, 1 381 453 (51.3%) were male, and the median (interquartile range) age was 32 (22-43) years. The study population consisted of 24 020 twins, 1 546 108 siblings, 264 244 half-siblings, and 1 044 546 cousins. In total, 61 861 (2.30%) unique individuals were diagnosed with syncope. Sixty-two percent (38 226) of the syncope-positive individuals were female. The odds ratio (OR) for syncope was 2.39 (95% CI, 1.61-3.53) for twins, 1.81 (95% CI, 1.71-1.91) for siblings, 1.28 (95% CI, 1.20-1.37) for half-siblings, and 1.13 (95% CI, 1.10-1.17) for cousins of individuals with syncope. The OR was highest among male twins at 5.03 (95% CI, 2.57-9.85). The proportion of syncope-positive individuals was consistently higher in women vs men, regardless of degree of relationship (twins: 346 [2.88%] vs 193 [1.61%]; siblings: 22 111 [2.92%] vs 13 419 [1.70%], half-siblings: 4148 [3.44%] vs 2425 [1.93%], cousins: 14 498 [2.87%] vs 9246 [1.72%]). Exclusion of nonreflex syncope diagnoses did not change syncope risk in affected families. CONCLUSIONS AND RELEVANCE In this Swedish national population-based study, the risk of syncope among relatives of affected individuals was associated with the relationship degree and was strongest in twins and siblings, which suggests that there are genetic components of reflex syncope. Women were more likely to experience syncope independently of family relationship. A better understanding of genetic predisposition to reflex syncope may offer new therapeutic options in severely affected individuals.
Collapse
Affiliation(s)
- Artur Fedorowski
- Department of Clinical Sciences, Lund University, Malmö, Sweden
- Department of Cardiology, Skåne University Hospital, Malmö, Sweden
| | - Mirnabi Pirouzifard
- Center for Primary Health Care Research, Lund University/Region Skåne, Malmö, Sweden
| | - Jan Sundquist
- Center for Primary Health Care Research, Lund University/Region Skåne, Malmö, Sweden
- Stanford Prevention Research Center, Stanford University School of Medicine, Palo Alto, California
| | - Kristina Sundquist
- Center for Primary Health Care Research, Lund University/Region Skåne, Malmö, Sweden
- Stanford Prevention Research Center, Stanford University School of Medicine, Palo Alto, California
| | - Richard Sutton
- Department of Cardiology, Skåne University Hospital, Malmö, Sweden
- National Heart and Lung Institute, Imperial College, Department of Cardiology, London, United Kingdom
| | - Bengt Zöller
- Center for Primary Health Care Research, Lund University/Region Skåne, Malmö, Sweden
| |
Collapse
|
14
|
Feigofsky S, Fedorowski A. Defining Cardiac Dysautonomia - Different Types, Overlap Syndromes; Case-based Presentations. J Atr Fibrillation 2020; 13:2403. [PMID: 33024503 DOI: 10.4022/jafib.2403] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 02/19/2020] [Accepted: 03/20/2020] [Indexed: 12/20/2022]
Abstract
The cardiovascular branch of autonomic nervous system (ANS) is responsible for the regulation of heart rate, blood pressure, and maintaining homeostasis during physiological stress such as exercise and standing upright. ANS constantly controls the rate and force of heart contractions and the vascular tone with the aim to maintain the sufficient tissue perfusion with oxygenated blood and secure venous return to the heart. Dysautonomias, result of ANS malfunction, are often found in patients with cardiovascular symptoms. Apart from the most prevalent one, arterial hypertension, the cardiovascular dysautonomic continuum encompasses other important although less known conditions: postural orthostatic tachycardia syndrome, inappropriate sinus tachycardia, orthostatic hypotension and reflex syncope. Moreover, heart diseases may evoke autonomic imbalance by themselves; cardiac pump failure is usually associated with sympathetic hyperactivity, neuroendocrine vasopressor activation, higher heart rate, reduced heart rate variability and baroreflex hyposensitivity, all of which are predictors of adverse outcomes. Cardiologists and electrophysiologist frequently see patients for the evaluation and management of unexplained syncope, orthostatic intolerance, heart rhythm abnormalities and symptoms of palpitations. Recognizing the presence of cardiac dysautonomia is an important skill which is necessary for the appropriate evaluation and treatment of these patients. Clinical presentations may overlap, and the importance of a thorough history cannot be over-emphasized. In this review we will present a cases of a patients with cardiac dysautonomia which is illustrative of a typical patient experience, followed by a review of the autonomic nervous system and discussion of prevalence, clinical presentation, and pathophysiology of common cardiac dysautonomias.
Collapse
Affiliation(s)
| | - Artur Fedorowski
- Department of Clinical Sciences, Lund University, 214 28 Malmö, Sweden.,Department of Cardiology, Skåne University Hospital, 214 28 Malmö, Sweden
| |
Collapse
|
15
|
Kapa S, Chung M, Gopinathannair R, Noseworthy P, Eckhardt L, Leal M, Wan E, Wang PJ. Year in Review in Cardiac Electrophysiology. Circ Arrhythm Electrophysiol 2020; 13:e008733. [PMID: 32423252 DOI: 10.1161/circep.120.008733] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In the past year, there have been numerous advances in our understanding of arrhythmia mechanisms, diagnosis, and new therapies. We have seen advances in basic cardiac electrophysiology with data suggesting that secretoneurin may be a biomarker for patients at risk of ventricular arrhythmias, and we have learned of the potential role of an NPR-C (natriuretic peptide receptor-C) in atrial fibrosis and the role of an atrial specific 2-pore potassium channel TASK-1 as a therapeutic target for atrial fibrillation. We have seen studies demonstrating the role of sensory neurons in sleep apnea-related atrial fibrillation and the association between bariatric surgery and atrial fibrillation ablation outcomes. Artificial intelligence applied to electrocardiography has yielded estimates of age, sex, and overall health. We have seen new tools for collection of patient-centered outcomes following catheter ablation. There have been significant advances in the ability to identify ventricular tachycardia termination sites through high-density mapping of deceleration zones. We have learned that right ventricular dysfunction may be a predictor of survival benefit after implantable cardioverter-defibrillator implantation in patients with nonischemic cardiomyopathy. We have seen further insights into the role of His bundle pacing on improving outcomes. As our understanding of cardiac laminopathies advances, we may have new tools to predict arrhythmic event rates in gene carriers. Finally, we have seen numerous advances in the treatment of arrhythmias in patients with congenital heart disease.
Collapse
Affiliation(s)
- Suraj Kapa
- Department of Medicine, Mayo Clinic, Rochester, MN (S.K., P.N.)
| | - Mina Chung
- Department of Medicine, Cleveland Clinic, OH (M.C.)
| | | | | | - Lee Eckhardt
- Department of Medicine, University of Wisconsin, Madison (L.E., M.L.)
| | - Miguel Leal
- Department of Medicine, University of Wisconsin, Madison (L.E., M.L.)
| | - Elaine Wan
- Department of Medicine, Columbia University, New York, NY (E.W.)
| | - Paul J Wang
- Department of Medicine, Stanford University, CA (P.J.W.)
| |
Collapse
|
16
|
Raj SR, Ahmed SB, Sheldon RS. Understanding vasovagal syncope: a role for sex and gender. Clin Auton Res 2020; 30:369-370. [PMID: 32300948 DOI: 10.1007/s10286-020-00689-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 04/09/2020] [Indexed: 01/11/2023]
Affiliation(s)
- Satish R Raj
- Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, University of Calgary, GAC70 HRIC Building, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada. .,Division of Clinical Pharmacology, Department of Medicine, Autonomic Dysfunction Center, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Sofia B Ahmed
- Department of Medicine, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
| | - Robert S Sheldon
- Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, University of Calgary, GAC70 HRIC Building, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada.,Department of Medicine, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
| |
Collapse
|
17
|
Syncope in Malaysian populations. Clin Auton Res 2020; 30:101-103. [DOI: 10.1007/s10286-019-00663-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 12/25/2019] [Indexed: 10/25/2022]
|
18
|
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.
Collapse
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.
| |
Collapse
|
19
|
Sheldon RS, Sandhu RK. The Search for the Genes of Vasovagal Syncope. Front Cardiovasc Med 2019; 6:175. [PMID: 31850372 PMCID: PMC6892747 DOI: 10.3389/fcvm.2019.00175] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 11/14/2019] [Indexed: 11/29/2022] Open
Abstract
Only humans faint, and not all do so. Syncope tends to recur, and the predisposition to syncope can persist over many decades. Observations such as these have suggested that there may be a genetic predisposition to vasovagal syncope. It seems to have a high prevalence in some families; having a parent who faints increases the likelihood of an offspring fainting, and this is increased even further if both biological parents faint. Numerous studies have correlated a number of genotypes with positive tilt tests. However, the control subjects are usually those who faint, but have negative tilt tests, making the conclusions about association with the clinical phenotype less certain. Twin studies, highly focused genome-wide association studies, and gene duplicate studies all suggest there are sites in the genome that associate with vasovagal syncope, although the specific genes, pathways, and proteins are unknown. A recent large, candidate gene study of kindreds with high, multigenerational prevalence of the vasovagal syncope identified 3 genes that associate with vasovagal syncope. Our understanding of the genetic correlates of vasovagal syncope is in its infancy, with much to be understood.
Collapse
Affiliation(s)
- Robert S Sheldon
- The Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada.,The Mazankowski Heart Institute, University of Alberta, Edmonton, AB, Canada
| | - Roopinder K Sandhu
- The Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada.,The Mazankowski Heart Institute, University of Alberta, Edmonton, AB, Canada
| |
Collapse
|
20
|
Tan MP, Ho YY, Chin AV, Saedon N, Abidin IZ, Chee KH, Khor HM, Goh CH, Hairi NN, Othman S, Kamaruzzaman SB. Ethnic differences in lifetime cumulative incidence of syncope: the Malaysian elders longitudinal research (MELoR) study. Clin Auton Res 2019; 30:121-128. [PMID: 31079241 DOI: 10.1007/s10286-019-00610-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 05/02/2019] [Indexed: 12/01/2022]
Abstract
PURPOSE To determine the lifetime cumulative incidence of syncope, potential ethnic differences and factors associated with syncope using the Malaysian elders longitudinal research (MELoR) study first wave dataset. METHODS The MELoR study recruited community-dwelling adults aged 55 years and over, selected through stratified random sampling from three parliamentary constituencies. The baseline data collected during the first wave was obtained through face-to-face interviews in participants' homes using computer-assisted questionnaires. During their baseline assessments, participants were asked whether they had ever experienced a blackout in their lifetime and if they had experienced a blackout in the preceding 12 months. RESULTS Information on blackouts and ethnicity were available for 1530 participants. The weight-adjusted lifetime cumulative incidence of syncope for the overall population aged 55 years and above was 27.7%. The estimated lifetime cumulative incidence according to ethnic groups was 34.6% for Malays, 27.8% for Indians and 23.7% for Chinese. The estimated 12-month incidence of syncope was 6.1% overall, equating to 11.7% for Malays, 8.7 % for Indians and 2.3% for Chinese. Both Malay [odds ratio (OR) 1.46; 95% confidence interval (CI) 1.10-1.95 and OR 3.62, 95% CI 1.96-6.68] and Indian (OR 1.34; 95% CI 1.01-1.80 and OR 3.31, 1.78-6.15) ethnicities were independently associated with lifetime and 12-month cumulative incidence of syncope, respectively, together with falls, dizziness and myocardial infarction. CONCLUSION Ethnic differences exist for lifetime cumulative incidence of syncope in community-dwelling individuals aged 55 years and over in an urban area in Southeast Asia. Future studies should now seek to determine potential genetic, cultural and lifestyle differences which may predispose to syncope.
Collapse
Affiliation(s)
- Maw Pin Tan
- Ageing and Age-Associated Disorders Research Group, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia. .,Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia. .,Department of Medical Sciences, School of Healthcare and Medical Sciences, Sunway University, Bandar Sunway, 47500, Selangor, Malaysia.
| | - Yun Ying Ho
- Department of Medicine, Tengku Ampuan Afzan Hospital, Kuantan, Malaysia
| | - Ai-Vyrn Chin
- Ageing and Age-Associated Disorders Research Group, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Nor'Izzati Saedon
- Ageing and Age-Associated Disorders Research Group, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Imran Zainal Abidin
- Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kok Han Chee
- Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Hui Min Khor
- Ageing and Age-Associated Disorders Research Group, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Choon Hian Goh
- Ageing and Age-Associated Disorders Research Group, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
| | - Noran Naqiah Hairi
- Department of Social and Preventive Medicine, Faculty of Medicine, Julius Centre University of Malaya, University of Malaya, Kuala Lumpur, Malaysia
| | - Sajarulnisah Othman
- Department of Primary Care Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Shahrul Bahyah Kamaruzzaman
- Ageing and Age-Associated Disorders Research Group, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| |
Collapse
|