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Neurally mediated reflex syncope

Last reviewed: 20 Aug 2025
Last updated: 17 Dec 2024

Summary

Definition

History and exam

Other diagnostic factors

  • history of recurrent faints
  • absence of structural heart disease
  • provocative factor
  • nausea
  • low risk for adverse outcomes
  • lightheadedness
  • pallor
  • diaphoresis
  • diminished vision or hearing
  • physical injury
  • fatigue after episode
  • palpitations
  • bradycardia
  • absence of family history of sudden death
  • neuralgia
Full details

Risk factors

  • prior syncope
  • prior history of arrhythmias, myocardial infarction, heart failure, or cardiomyopathy
  • severe aortic stenosis
  • prolonged standing
  • emotional stress (especially in a warm, crowded environment)
  • dehydration/hypovolemia
  • preceding episode of nausea and/or vomiting
  • preceding episode of severe pain
Full details

Diagnostic tests

1st tests to order

  • 12-lead ECG
  • serum hemoglobin
  • plasma blood glucose
  • serum beta-hCG (human chorionic gonadotropin)
  • cardiac enzymes
  • D-dimer level
  • serum cortisol
  • BUN and serum creatinine
Full details

Tests to avoid

  • electroencephalogram (EEG)
  • carotid artery imaging
  • neurologic imaging (CT, MRI)
Full details

Tests to consider

  • echocardiogram
  • tilt-table test
  • carotid sinus massage (CSM)
  • insertable loop recorder
  • electrophysiologic study
  • Valsalva maneuver
  • active standing test
  • cold pressor test
  • cough test
Full details

Treatment algorithm

ACUTE

vasovagal faint

situational faint

carotid sinus syndrome

Contributors

Authors

Bryant Lin, MD
Bryant Lin

Clinical Assistant Professor of Medicine

Division of Primary Care and Population Health

Stanford University School of Medicine

Stanford

CA

Disclosures

BL declares that he has no competing interests.

Paul J. Wang, MD, FACC, FHRS
Paul J. Wang

Professor of Medicine

Stanford Arrhythmia Service

Stanford University School of Medicine

Stanford

CA

Divulgaciones

PJW receives fellowship support, honoraria, and clinical trial support from Medtronic, which manufactures LINQ, an implantable loop recorder.

Agradecimientos

Dr Bryant Lin and Dr Paul J. Wang would like to gratefully acknowledge Dr David G. Benditt and Dr John T. Nguyen, previous contributors to this topic.

Divulgaciones

DGB has consultant and equity positions: Medtronic Inc., St Jude Medical Inc., Transoma Inc., Cardionet Inc. DGB is also an author of several references cited in this topic. JTN declares that he has no competing interests.

Revisores por pares

Sanjiv Petkar, MBBS, MD, DM (Cardiology), MRCP

Consultant Cardiologist

Hull and East Riding of Yorkshire NHS Trust

Castle Hill Hospital

East Yorkshire

UK

Divulgaciones

SP has received sponsorship in the past from Medtronic, Inc. and St Jude Medical, Inc. for attending conferences. He has received speaker's fees from Medtronic, Inc. In addition, he was in receipt of a research grant from Medtronic, Inc. to the University of Manchester.

Kenneth A. Ellenbogen, MD

Kontos Professor of Cardiology

Medical College of Virginia

Richmond

VA

Divulgaciones

KAE declares that he has no competing interests.

Andrew Parfitt, MBBS, FFAEM

Clinical Director

Acute Medicine

Associate Medical Director

Consultant Emergency Medicine

Guy's and St Thomas' NHS Foundation Trust

Clinical Lead and Consultant

Accident Emergency Medicine

St Thomas' Hospital

London

UK

Divulgaciones

AP declares that he has no competing interests.

Peer reviewer acknowledgements

BMJ Best Practice topics are updated on a rolling basis in line with developments in evidence and guidance. The peer reviewers listed here have reviewed the content at least once during the history of the topic.

Disclosures

Peer reviewer affiliations and disclosures pertain to the time of the review.

Referencias

Nuestros equipos internos de evidencia y editoriales colaboran con colaboradores expertos internacionales y revisores pares para garantizar que brindemos acceso a la información más clínicamente relevante posible.

Artículos principales

Shen WK, Sheldon RS, Benditt DG, et al. 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope: a report of the American College of Cardiology/American Heart Association Task Force on clinical practice guidelines, and the Heart Rhythm Society. Heart Rhythm. 2017 Aug;14(8):e155-217.Texto completo  Resumen

Brignole M, Moya A, de Lange FJ, et al; ESC Scientific Document Group. 2018 ESC guidelines for the diagnosis and management of syncope. Eur Heart J. 2018 Jun 1;39(21):1883-948.Texto completo  Resumen

Moya A, Brignole M, Menozzi C, et al; International Study on Syncope of Uncertain Etiology (ISSUE) Investigators. Mechanism of syncope in patients with isolated syncope and in patients with tilt-positive syncope. Circulation. 2001 Sep 11;104(11):1261-7.Texto completo  Resumen

Sandhu RK, Raj SR, Manlucu J, et al; Primary Writing Committee. Canadian Cardiovascular Society clinical practice update on the assessment and management of syncope. Can J Cardiol. 2020 Aug;36(8):1167-77.Texto completo  Resumen

Reed MJ, Newby DE, Coull AJ, et al. The ROSE (risk stratification of syncope in the emergency department) study. J Am Coll Cardiol. 2010 Feb 23;55(8):713-21.Texto completo  Resumen

Benditt DG, Ferguson DW, Grubb BP, et al. Tilt table testing for assessing syncope. American College of Cardiology. J Am Coll Cardiol. 1996 Jul;28(1):263-75. Resumen

Raviele A, Giada F, Menozzi C, et al; Vasovagal Syncope and Pacing Trial Investigators. A randomized, double-blind, placebo-controlled study of permanent cardiac pacing for the treatment of recurrent tilt-induced vasovagal syncope. The Vasovagal Syncope and Pacing Trial (SYNPACE). Eur Heart J. 2004 Oct;25(19):1741-8.Texto completo  Resumen

Artículos de referencia

Una lista completa de las fuentes a las que se hace referencia en este tema está disponible para los usuarios con acceso a todo BMJ Best Practice.
  • Diferenciales

    • Orthostatic syncope (postural or orthostatic intolerance syncope syndromes)
    • Bradycardia
    • Bradycardia: AV conduction disorders
    Más Diferenciales
  • Guías de práctica clínica

    • Recommendations for tilt table testing and other provocative cardiovascular autonomic tests in conditions that may cause transient loss of consciousness
    • 2018 ESC guidelines for the diagnosis and management of syncope
    Más Guías de práctica clínica
  • Folletos para el paciente

    Atrial fibrillation

    Febrile seizures

    Más Folletos para el paciente
  • Calculadoras

    San Francisco Syncope Rule TreeCalc

    ROSE score: risk stratification of syncope in the emergency department

    Más Calculadoras
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