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

9.4K
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
9.4K
Electrophysiology of Normal Cardiac Rhythm01:19

Electrophysiology of Normal Cardiac Rhythm

10.4K
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...
10.4K
Correlation between ECG and Cardiac Cycle01:25

Correlation between ECG and Cardiac Cycle

15.4K
The electrical signals recorded on an electrocardiogram (ECG) occur before the mechanical processes of contraction and relaxation during the cardiac cycle.
A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before...
15.4K
The Cardiac Cycle01:13

The Cardiac Cycle

101.7K
The heart beats rhythmically in a sequence called the cardiac cycle—a rapid coordination of contraction (systole) and relaxation (diastole).
The Process
Electrical signals—sent from the sinoatrial (SA) node in the right atrial wall to the atrioventricular (AV) node between the right atrium and right ventricle—cause both atria to simultaneously contract. When the signal reaches the AV node, it pauses for approximately a tenth of a second, allowing the atria to contract and...
101.7K
Specialized Characteristics of Cardiac Muscles01:27

Specialized Characteristics of Cardiac Muscles

5.3K
The primary role of cardiac muscles is to propel blood throughout the cardiovascular system. The cardiac muscle cells, or cardiomyocytes, exhibit specialized characteristics that allow them to perform this function.
Cardiac muscle cells are smaller than skeletal muscles, averaging 10–20 mm in diameter and 50–100 mm in length. However, they have large energy demands for continuous contraction and relaxation. This energy is almost exclusively derived from aerobic metabolism of energy...
5.3K
Conduction System of the Heart01:20

Conduction System of the Heart

5.5K
The cardiac conduction system produces and transmits electrical impulses that prompt myocardial contraction, ensuring efficient heart function. This intricate system ensures that the heart beats in a coordinated and efficient manner, beginning with the atria and then the ventricles. The conduction system optimizes cardiac output by maintaining this precise sequence, which is crucial for adequate blood circulation.
This system relies on the unique properties of nodal and Purkinje cells:...
5.5K

You might also read

Related Articles

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

Sort by
Same author

Computational Modelling of Selective Capture Mechanisms in Conduction System Pacing.

Annals of biomedical engineering·2026
Same author

Cryoballoon Versus Radiofrequency Ablation for Persistent Atrial Fibrillation: Meta-Analysis of Randomized Trials.

Pacing and clinical electrophysiology : PACE·2026
Same author

Tau20-RETROmapping System Identifies Driver-Like Activation Patterns in Real-Time During Persistent Atrial Fibrillation.

Circulation. Arrhythmia and electrophysiology·2026
Same author

Atrial cardiomyopathy as a multidomain disease: longitudinal evidence for autonomic remodelling.

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·2026
Same author

Combined emission ratiometry and motion tracking for optical mapping of contracting hearts: Validation with monophasic action potentials.

The Journal of physiology·2026
Same author

Role of interatrial connection ablation in re-entry dynamics: an in silico evaluation.

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·2026

Related Experiment Video

Updated: Apr 6, 2026

Preclinical Cardiac Electrophysiology Assessment by Dual Voltage and Calcium Optical Mapping of Human Organotypic Cardiac Slices
09:35

Preclinical Cardiac Electrophysiology Assessment by Dual Voltage and Calcium Optical Mapping of Human Organotypic Cardiac Slices

Published on: June 16, 2020

11.0K

Transmural APD gradient synchronizes repolarization in the human left ventricular wall.

Bastiaan J Boukens1, Matthew S Sulkin2, Chris R Gloschat1

  • 1Department of Biomedical Engineering, George Washington University, 5000 Science and Engineering Hall, 800 22ng Street NW, Washington, DC 20052, USA.

Cardiovascular Research
|July 26, 2015
PubMed
Summary

The transmural gradient in action potential duration (APD) synchronizes ventricular repolarization. However, this APD gradient does not fully explain the T wave

Keywords:
HumanOptical mappingRepolarizationT wave

More Related Videos

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

2.2K
Subtype-specific Optical Action Potential Recordings in Human Induced Pluripotent Stem Cell-derived Ventricular Cardiomyocytes
06:59

Subtype-specific Optical Action Potential Recordings in Human Induced Pluripotent Stem Cell-derived Ventricular Cardiomyocytes

Published on: September 27, 2018

7.6K

Related Experiment Videos

Last Updated: Apr 6, 2026

Preclinical Cardiac Electrophysiology Assessment by Dual Voltage and Calcium Optical Mapping of Human Organotypic Cardiac Slices
09:35

Preclinical Cardiac Electrophysiology Assessment by Dual Voltage and Calcium Optical Mapping of Human Organotypic Cardiac Slices

Published on: June 16, 2020

11.0K
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

2.2K
Subtype-specific Optical Action Potential Recordings in Human Induced Pluripotent Stem Cell-derived Ventricular Cardiomyocytes
06:59

Subtype-specific Optical Action Potential Recordings in Human Induced Pluripotent Stem Cell-derived Ventricular Cardiomyocytes

Published on: September 27, 2018

7.6K

Area of Science:

  • Cardiac Electrophysiology
  • Cardiovascular Physiology
  • Computational Biology

Background:

  • The T wave on an electrocardiogram (ECG) is crucial for predicting ventricular fibrillation risk.
  • A transmural gradient in action potential duration (APD) across the ventricular wall is hypothesized to shape the human T wave.
  • Understanding this gradient's role is key to deciphering cardiac repolarization mechanisms.

Purpose of the Study:

  • To investigate if the transmural APD gradient compensates for the endocardium-to-epicardium activation sequence.
  • To determine if this gradient synchronizes repolarization in the human ventricular wall.
  • To clarify the relationship between APD gradients and T wave morphology.

Main Methods:

  • Utilized left ventricular wedge preparations from human donor hearts.
  • Employed optical mapping to measure transmural activation and repolarization patterns.
  • Simultaneously recorded pseudo-ECG and performed in silico simulations.

Main Results:

  • Found that subendocardial APD was longer than subepicardial APD during endocardial pacing.
  • Observed that transmural activation time was 32 ± 4 ms.
  • Demonstrated that transmural repolarization time dispersion was less than APD dispersion, and T wave morphology remained constant despite varying APD gradients.

Conclusions:

  • The intrinsic transmural APD difference aids in homogeneous left ventricular wall repolarization.
  • Transmural repolarization differences alone do not fully account for the T wave's genesis.
  • T wave morphology may be independent of transmural APD gradients.