Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Dysrhythmias IV: Characteristics of Bradyarrhythmias01:18

Dysrhythmias IV: Characteristics of Bradyarrhythmias

Bradyarrhythmias are cardiac rhythm disorders characterized by a slower-than-normal heart rate, typically defined as fewer than 60 beats per minute. Some of which are discussed here:Sinus BradycardiaSinus bradycardia presents a heart rate lower than 60 beats per minute, with a regular rhythm originating from the SA node. The ECG typically shows normal P waves preceding each QRS complex, a normal PR interval (0.12 to 0.20 seconds), and a normal QRS duration (0.06 to 0.10 seconds).First-Degree AV...
Disturbances in Heart Rhythm01:29

Disturbances in Heart Rhythm

Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias.
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
Cardiac Action Potential01:30

Cardiac Action Potential

Cardiac action potentials are essential for proper heart function, enabling the rhythmic contractions needed for adequate blood circulation. Nodal cells and Purkinje fibers, specialized for electrical conduction, generate these action potentials.
The cardiac action potential process involves a series of phases characterized by the movement of ions across the cardiac cell membranes, leading to the depolarization and repolarization of the cardiac myocytes.
Ionic Basis of Cardiac Action Potentials
Dysrhythmias I: Introduction01:15

Dysrhythmias I: Introduction

Dysrhythmias refers to abnormalities in the heart's rhythm. They result from disruptions in the heart's electrical conduction system, which includes the sinoatrial(SA)node, atrioventricular(AV) node, the bundle of His, bundle branches, and Purkinje fibers.Definition and PathophysiologyDysrhythmias result from disorders of impulse formation, impulse conduction, or both. The heart contains specialized cells in the sinoatrial node, atrioventricular node, and the bundle of His and Purkinje fibers...
ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias01:25

ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias

Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an...
Mechanism of Cardiac Arrhythmias01:28

Mechanism of Cardiac Arrhythmias

Arrhythmias are irregular heart rhythms occurring when the heart's electrical impulses become abnormal. These disturbances can lead to various symptoms, depending on their severity and the underlying cause. Some common factors contributing to arrhythmias include hypoxia, ischemia, electrolyte imbalances, excessive catecholamine exposure, drug toxicity, and muscle overstretching. Arrhythmias can be classified into two main types based on the rate and site of origin of abnormal heart rhythms.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

A Dizzying Number of Clinical Decision Rules … and Do We Need Them?

Academic emergency medicine : official journal of the Society for Academic Emergency Medicine·2026
Same author

Understanding the blind spots: insights into diagnostic errors in neurological emergencies.

CJEM·2026
Same author

When Dinner Becomes Dangerous-Alpha-Gal Syndrome as a Diagnostic Pitfall in the Emergency Department: An Illustrative Case Presentation.

Journal of emergency nursing·2026
Same author

Clinical Risk Scores to Stratify for Serious Causes of Vertigo.

Annals of emergency medicine·2025
Same author

Acute Vertigo, Dizziness and Imbalance in the Emergency Department-Beyond Stroke and Acute Unilateral Vestibulopathy-A Narrative Review.

Brain sciences·2025
Same author

Reply to Vestibular Migraine or Transitory Ischemic Attack in the Posterior Circulation-How to Differentiate.

The Journal of emergency medicine·2025
Same journal

Incorrect Table Entries and Word.

Archives of neurology·2016
Same journal

IDEAL for CCSVI Research-Reply.

Archives of neurology·2013
Same journal

Atlas of Inherited Metabolic Diseases, 3rd ed.

Archives of neurology·2013
Same journal

Error in byline: in heterogeneity of coenzyme q10 deficiency: patient study and literature review.

Archives of neurology·2013
Same journal

This month in archives of neurology.

Archives of neurology·2013
Same journal

About this journal.

Archives of neurology·2013
See all related articles

Related Experiment Video

Updated: Jun 8, 2026

Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System
10:17

Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System

Published on: April 11, 2025

Complete heart block complicating the head impulse test.

Edward Ullman1, Jonathan A Edlow

  • 1Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA. eullman@bidmc.harvard.edu

Archives of Neurology
|October 13, 2010
PubMed
Summary
This summary is machine-generated.

The head impulse test (HIT) can diagnose vestibular syndrome but may rarely cause a severe vagal reaction. Physicians should be aware of this potential complication during clinical use.

More Related Videos

Implantation of Total Artificial Heart in Congenital Heart Disease
07:27

Implantation of Total Artificial Heart in Congenital Heart Disease

Published on: July 18, 2014

Optimization of Transesophageal Atrial Pacing to Assess Atrial Fibrillation Susceptibility in Mice
08:05

Optimization of Transesophageal Atrial Pacing to Assess Atrial Fibrillation Susceptibility in Mice

Published on: June 29, 2022

Related Experiment Videos

Last Updated: Jun 8, 2026

Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System
10:17

Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System

Published on: April 11, 2025

Implantation of Total Artificial Heart in Congenital Heart Disease
07:27

Implantation of Total Artificial Heart in Congenital Heart Disease

Published on: July 18, 2014

Optimization of Transesophageal Atrial Pacing to Assess Atrial Fibrillation Susceptibility in Mice
08:05

Optimization of Transesophageal Atrial Pacing to Assess Atrial Fibrillation Susceptibility in Mice

Published on: June 29, 2022

Area of Science:

  • Neurology
  • Cardiology
  • Otolaryngology

Background:

  • Acute vestibular syndrome presents with dizziness, nausea, vomiting, and postural instability, stemming from peripheral or central lesions.
  • Differentiating lesion types is crucial as treatments vary significantly.
  • The head impulse test (HIT) is a bedside clinical tool used to distinguish between peripheral and central vestibular lesions.

Observation:

  • A case report details a 52-year-old woman presenting with sudden dizziness.
  • The patient underwent the head impulse test (HIT) to evaluate the cause of her dizziness.
  • Complete heart block was observed immediately following the performance of the HIT.

Findings:

  • The head impulse test (HIT) can precipitate a severe vagal reaction in susceptible patients.
  • Complete heart block is a rare but possible adverse event associated with the HIT.

Implications:

  • Clinicians performing the HIT in various settings should be vigilant for potential severe vagal reactions.
  • Awareness of this risk can aid in prompt recognition and management of adverse events during vestibular testing.