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

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
Electrophysiology of Normal Cardiac Rhythm01:19

Electrophysiology of Normal Cardiac Rhythm

The normal cardiac rhythm is a synchronized electrical activity that facilitates the regular and coordinated contraction of the heart muscle. This process is essential for efficient blood circulation throughout the body. The fundamental elements involved in establishing and maintaining this rhythm include the unique electrical properties of cardiac muscle cells, the sinoatrial (SA) node's pacemaker function, the specialized conducting system, and the ionic mechanisms underlying each phase of...
Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers01:12

Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers

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 the heart's...
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.
Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers01:22

Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers

Class I antiarrhythmic drugs are used to treat various types of arrhythmias or irregular heart rhythms. These drugs block the sodium (Na+) channels in the cardiac cells, thereby affecting the movement of electrical impulses across the heart. Class I antiarrhythmic drugs are divided into three subgroups: Class IA, Class IB, and Class IC, each with distinct mechanisms of action and effects on the heart.
Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...
Action Potential: Phases of Stimulation01:28

Action Potential: Phases of Stimulation

The action potential is a complex electrical event that occurs in excitable cells, such as neurons and muscle cells. It consists of several distinct phases, each with specific characteristics.
Resting Phase:
In this phase, the cell's membrane is at its resting potential, typically around -70 millivolts (mV) for neurons. Inside the cell, there is a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+). Voltage-gated sodium channels are closed, and...

You might also read

Related Articles

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

Sort by
Same author

Macrophage recruitment is a hallmark of non-syndromic myxomatous mitral valve disease.

Cardiovascular research·2026
Same author

SPARC: a structural pathogenicity algorithm for risk classification of hERG variants.

Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology·2025
Same author

Anti-TRPV2 Autoantibody Linked to Sudden Infant Death Syndrome.

Circulation·2025
Same author

Long QT syndrome type 3 gain-of-function of Na<sub>v</sub>1.5 increases ventricular fibroblasts proliferation and pro-fibrotic factors.

Communications biology·2025
Same author

Cardiac Gene Therapy With Phosphodiesterase 2A Limits Remodeling and Arrhythmias in Mouse Models of Heart Failure.

Journal of the American Heart Association·2025
Same author

Isolated prolapse of the posterior mitral valve leaflet: phenotypic refinement, heritability and genetic etiology.

medRxiv : the preprint server for health sciences·2024

Related Experiment Video

Updated: Jun 21, 2026

Isolation and Functional Characterization of Human Ventricular Cardiomyocytes from Fresh Surgical Samples
14:39

Isolation and Functional Characterization of Human Ventricular Cardiomyocytes from Fresh Surgical Samples

Published on: April 21, 2014

Delayed rectifier K(+) currents and cardiac repolarization.

Flavien Charpentier1, Jean Mérot, Gildas Loussouarn

  • 1INSERM, UMR915, l'institut du thorax, Nantes, F-44000, France.

Journal of Molecular and Cellular Cardiology
|August 18, 2009
PubMed
Summary

This review details cardiac ion channels (IKs and IKr) that control heart rhythm. Recent research explores their molecular mechanisms, protein interactions, and expression in heart tissue.

More Related Videos

Voltage-Dependent Potassium Current Recording on H9c2 Cardiomyocytes via the Whole-Cell Patch-Clamp Technique
08:11

Voltage-Dependent Potassium Current Recording on H9c2 Cardiomyocytes via the Whole-Cell Patch-Clamp Technique

Published on: November 11, 2022

Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents
10:53

Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents

Published on: July 3, 2013

Related Experiment Videos

Last Updated: Jun 21, 2026

Isolation and Functional Characterization of Human Ventricular Cardiomyocytes from Fresh Surgical Samples
14:39

Isolation and Functional Characterization of Human Ventricular Cardiomyocytes from Fresh Surgical Samples

Published on: April 21, 2014

Voltage-Dependent Potassium Current Recording on H9c2 Cardiomyocytes via the Whole-Cell Patch-Clamp Technique
08:11

Voltage-Dependent Potassium Current Recording on H9c2 Cardiomyocytes via the Whole-Cell Patch-Clamp Technique

Published on: November 11, 2022

Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents
10:53

Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents

Published on: July 3, 2013

Area of Science:

  • Cardiology
  • Molecular Biology
  • Electrophysiology

Background:

  • Cardiac delayed rectifier potassium currents (IKs and IKr) are crucial for regulating heart action potential duration.
  • These currents are primarily mediated by KCNQ1/KCNE1 (IKs) and HERG (IKr) channels.
  • Dysfunction of these channels is linked to cardiac channelopathies.

Purpose of the Study:

  • To review major studies on IKs and IKr.
  • To discuss recent findings on the molecular mechanisms, trafficking, activity, and regulation of these cardiac channels.
  • To highlight the role of interacting partners and tissue-specific expression.

Main Methods:

  • Literature review of published research on IKs and IKr.
  • Analysis of studies on channel subunit identification (KCNQ1, KCNE1, HERG).
  • Examination of research on channelopathies and molecular mechanisms.

Main Results:

  • Identification of KCNQ1/KCNE1 and HERG as the primary subunits for IKs and IKr.
  • Elucidation of molecular mechanisms governing channel trafficking, activity, and regulation.
  • Discovery of protein partners influencing channel function and degradation.
  • Characterization of heterogeneous expression patterns within cardiac tissue.

Conclusions:

  • IKs and IKr are essential for cardiac electrical activity and are tightly regulated.
  • Understanding channel subunit interactions and expression is key to comprehending their precise cardiac function.
  • This review synthesizes current knowledge and recent advances in the field.