Neurally mediated reflex syncope

Last reviewed: 17 Apr 2022
Last updated: 24 Aug 2018

Summary

Definition

History and exam

Other diagnostic factors

  • low risk for adverse outcomes
  • hx of recurrent faints
  • provocative factor
  • nausea
  • lightheadedness
  • pallor
  • diaphoresis
  • diminished vision or hearing
  • physical injury
  • fatigue after episode
  • palpitations
  • bradycardia
  • absence of FHx of sudden death
  • neuralgia
Other diagnostic factors

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
More risk factors

Diagnostic investigations

1st investigations to order

  • 12-lead ECG
  • serum hemoglobin
  • plasma blood glucose
  • serum beta-HCG
  • cardiac enzymes
  • D-dimer level
  • serum cortisol
  • BUN and serum creatinine
More 1st investigations to order

Investigations 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
More investigations to consider

Emerging tests

  • adenosine triphosphate (ATP) test

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

Disclosures

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

Acknowledgements

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 monograph. 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 monograph. JTN declares that he has no competing interests.

Peer reviewers

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

Consultant Cardiologist

Hull and East Riding of Yorkshire NHS Trust

Castle Hill Hospital

East Yorkshire

UK

Disclosures

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

Disclosures

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

Disclosures

AP declares that he has no competing interests.

  • Differentials

    • Orthostatic syncope (postural or orthostatic intolerance syncope syndromes)
    • Bradycardia
    • Bradycardia: AV conduction disorders
    More Differentials
  • Guidelines

    • 2018 ESC Guidelines for the diagnosis and management of syncope
    • ACC/AHA/HRS guideline for the evaluation and management of patients with syncope
    More Guidelines
  • Patient leaflets

    Atrial fibrillation

    Febrile seizures

    More Patient leaflets
  • padlock-lockedLog in or subscribe to access all of BMJ Best Practice

Use of this content is subject to our disclaimer