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

133
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...
133
ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias01:25

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

181
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...
181
Mechanism of Cardiac Arrhythmias01:28

Mechanism of Cardiac Arrhythmias

1.1K
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.
1.1K
Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers01:12

Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers

1.3K
Class III antiarrhythmic drugs are a group of medications that can prolong action potentials in the heart. They achieve this by blocking potassium channels or enhancing inward currents from sodium channels. However, these drugs have a unique property of "reverse use-dependence," which is most pronounced at slower heart rates and can lead to torsades de pointes—a specific type of arrhythmia. However, it is essential to note that excessive QT interval prolongation—a measure of...
1.3K
Dysrhythmias I: Introduction01:15

Dysrhythmias I: Introduction

177
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...
177
Dysrhythmias II: Classification of Tachyarrhythmias01:28

Dysrhythmias II: Classification of Tachyarrhythmias

144
Tachyarrhythmias are a type of dysrhythmia where the heart rate exceeds 100 beats per minute. Here are some common types of tachyarrhythmias:Sinus TachycardiaSinus tachycardia originates from increased impulses from the sinus node, leading to an elevated heart rate. It is often triggered by stress, fever, or exercise.Patients may experience palpitations, a sensation of a racing heart, dizziness, and chest discomfort.Causes and Risk Factors: Common causes include physical exertion, emotional...
144

You might also read

Related Articles

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

Sort by
Same author

Association between interventional cardiologist practice characteristics, CABG use, and clinical outcomes.

European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery·2026
Same author

Scope and Outcome of Early Repolarization Syndrome in Unexplained Cardiac Arrest: Insights From the National HiRO Registry.

Circulation. Arrhythmia and electrophysiology·2026
Same author

Epinephrine Challenge: Long-Term Evaluation of Test Performance for the Evaluation of Unexplained Cardiac Arrest and Familial Sudden Death.

JACC. Clinical electrophysiology·2026
Same author

Pace and Ablate or Pace Then Ablate: Defining the Risk of Concomitant AV Node Ablation and Pacemaker Implantation Using a Probability Based Approach.

Circulation. Arrhythmia and electrophysiology·2026
Same author

2026 HRS/AHA/APHRS/EHRA/IDSA/LAHRS/PACES/STS expert consensus statement update on cardiovascular implantable electronic device lead management and extraction.

Heart rhythm·2026
Same author

Burst Exercise Stress Testing in Catecholaminergic Polymorphic Ventricular Tachycardia.

JAMA cardiology·2026

Related Experiment Video

Updated: Sep 22, 2025

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation
07:15

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation

Published on: January 16, 2019

11.1K

Congenital Long QT Syndrome.

Andrew D Krahn1, Zachary Laksman1, Raymond W Sy2

  • 1Center for Cardiovascular Innovation, Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, BC, Canada.

JACC. Clinical Electrophysiology
|May 19, 2022
PubMed
Summary
This summary is machine-generated.

Congenital long QT syndrome (LQTS) is a heritable heart condition affecting cardiac repolarization. Diagnosis and management involve clinical, ECG, and genetic factors to prevent sudden cardiac death.

Keywords:
arrhythmiainheritedsudden death

More Related Videos

Electrocardiogram Recordings in Anesthetized Mice using Lead II
04:16

Electrocardiogram Recordings in Anesthetized Mice using Lead II

Published on: June 20, 2020

13.2K
Electrophysiological Analysis of human Pluripotent Stem Cell-derived Cardiomyocytes hPSC-CMs Using Multi-electrode Arrays MEAs
11:13

Electrophysiological Analysis of human Pluripotent Stem Cell-derived Cardiomyocytes hPSC-CMs Using Multi-electrode Arrays MEAs

Published on: May 12, 2017

20.3K

Related Experiment Videos

Last Updated: Sep 22, 2025

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation
07:15

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation

Published on: January 16, 2019

11.1K
Electrocardiogram Recordings in Anesthetized Mice using Lead II
04:16

Electrocardiogram Recordings in Anesthetized Mice using Lead II

Published on: June 20, 2020

13.2K
Electrophysiological Analysis of human Pluripotent Stem Cell-derived Cardiomyocytes hPSC-CMs Using Multi-electrode Arrays MEAs
11:13

Electrophysiological Analysis of human Pluripotent Stem Cell-derived Cardiomyocytes hPSC-CMs Using Multi-electrode Arrays MEAs

Published on: May 12, 2017

20.3K

Area of Science:

  • Cardiology
  • Genetics
  • Electrophysiology

Background:

  • Congenital long QT syndrome (LQTS) is a group of heritable cardiac conditions.
  • Characterized by cardiac repolarization dysfunction, LQTS affects approximately 1 in 2,000 individuals, with a slight female predominance.
  • Understanding of LQTS has significantly advanced since its initial description in 1957.

Purpose of the Study:

  • To review the current understanding of congenital long QT syndrome (LQTS).
  • To provide a practical approach for the diagnosis and management of LQTS.
  • To highlight risk stratification factors and therapeutic strategies for LQTS patients.

Main Methods:

  • Review of existing literature on congenital long QT syndrome (LQTS).
  • Synthesis of clinical, electrocardiogram (ECG), and genetic diagnostic factors.
  • Analysis of current risk stratification and management strategies, including conservative, pharmacologic, and interventional approaches.

Main Results:

  • LQTS diagnosis integrates clinical presentation, ECG findings, and genetic testing.
  • Risk stratification considers age, sex, QTc interval, and genetic background.
  • Management includes avoiding QT-prolonging drugs, beta-blockers, and considering device therapy or sympathetic denervation for high-risk individuals.

Conclusions:

  • Effective management of LQTS involves a multi-faceted approach.
  • Most adequately treated patients can safely engage in exercise.
  • Implantable cardioverter-defibrillator therapy is reserved for the highest-risk LQTS patients.