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

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...
Electrocardiogram01:29

Electrocardiogram

An electrocardiogram (ECG or EKG) is a critical diagnostic tool that records the electrical signals produced by the heart during each heartbeat. This recording is achieved through electrodes placed strategically on the arms, legs, and chest. The electrocardiograph amplifies these signals and produces 12 distinct tracings, offering a comprehensive understanding of the heart's electrical activity.
Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T...
Correlation between ECG and Cardiac Cycle01:25

Correlation between ECG and Cardiac Cycle

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...
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
Electrocardiogram Fundamentals01:28

Electrocardiogram Fundamentals

Introduction
An electrocardiogram (ECG) is a diagnostic tool for identifying cardiac conditions such as arrhythmias, conduction abnormalities, and myocardial ischemia.
Definition
An electrocardiogram (ECG) visualizes the heart's electrical activity by tracing the electrical movement associated with each heartbeat on a graph or monitor. As the heart beats, an electrical wave passes through it, correlating with the cardiac cycle events.
Parts of an ECG
An ECG utilizes electrodes on the skin to...
ECG Interpretation of Rhythms01:24

ECG Interpretation of Rhythms

An electrocardiogram (ECG)graphically represents the heart's electrical activity on ECG paper or a monitor.
Components of the Electrocardiogram
The primary components of a normal ECG waveform in Normal sinus rhythm(NSR) include the P wave, PR interval, QRS complex, ST segment, T wave, and occasionally a U wave.
ECG waveforms are divided by vertical and horizontal lines at standard intervals.
The horizontal axis measures time and rate, and the vertical axis measures amplitude or voltage. When...

You might also read

Related Articles

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

Sort by
Same author

Identification of mega-environments and rice genotypes for general and specific adaptation to saline and alkaline stresses in India.

Scientific reports·2017
Same author

The control of NAD specific malic enzyme from cauliflower bud mitochondria by metabolites.

Planta·2014
Same author

The association of cigarette smoking with alveolar bone loss in postmenopausal females.

Journal of clinical periodontology·2000
Same author

Treatment of multifocal atrial tachycardia by treatment of pulmonary insufficiency: or is it vice versa?

Chest·2000
Same author

Longitudinal alveolar bone loss in postmenopausal osteoporotic/osteopenic women.

Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA·1999
Same author

Influence of estrogen and osteopenia/osteoporosis on clinical periodontitis in postmenopausal women.

Journal of periodontology·1999

Related Experiment Video

Updated: Jul 28, 2026

A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis
18:11

A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis

Published on: December 28, 2012

Reproducibility of the signal-averaged electrocardiogram.

T R Engel1, D L Pierce, K D Patil

  • 1Department of Internal Medicine, University of Nebraska College of Medicine, Omaha.

American Heart Journal
|December 1, 1991
PubMed
Summary

Signal-averaged electrocardiogram (SAECG) measurements show considerable variation, especially in high-frequency voltage. Noise significantly impacts voltage consistency, while duration measurements remain less affected.

More Related Videos

Microelectrode Array Recording of Sinoatrial Node Firing Rate to Identify Intrinsic Cardiac Pacemaking Defects in Mice
09:20

Microelectrode Array Recording of Sinoatrial Node Firing Rate to Identify Intrinsic Cardiac Pacemaking Defects in Mice

Published on: July 5, 2021

BrainBeats as an Open-Source EEGLAB Plugin to Jointly Analyze EEG and Cardiovascular Signals
08:22

BrainBeats as an Open-Source EEGLAB Plugin to Jointly Analyze EEG and Cardiovascular Signals

Published on: April 26, 2024

Related Experiment Videos

Last Updated: Jul 28, 2026

A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis
18:11

A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis

Published on: December 28, 2012

Microelectrode Array Recording of Sinoatrial Node Firing Rate to Identify Intrinsic Cardiac Pacemaking Defects in Mice
09:20

Microelectrode Array Recording of Sinoatrial Node Firing Rate to Identify Intrinsic Cardiac Pacemaking Defects in Mice

Published on: July 5, 2021

BrainBeats as an Open-Source EEGLAB Plugin to Jointly Analyze EEG and Cardiovascular Signals
08:22

BrainBeats as an Open-Source EEGLAB Plugin to Jointly Analyze EEG and Cardiovascular Signals

Published on: April 26, 2024

Area of Science:

  • Cardiology
  • Biomedical Engineering
  • Signal Processing

Background:

  • Signal-averaged electrocardiograms (SAECGs) are used to assess cardiac electrical activity.
  • High-frequency QRS potentials and low-amplitude signals are important parameters in SAECG analysis.
  • Understanding measurement variability is crucial for accurate interpretation of SAECG data.

Purpose of the Study:

  • To examine the variation in signal-averaged electrocardiogram measurements.
  • To assess the influence of noise on the consistency of SAECG parameters.
  • To compare the variability of high-frequency QRS durations, low-amplitude signal durations, and percent high-frequency voltages.

Main Methods:

  • Signal-averaged electrocardiograms were recorded from 18 normal subjects.
  • Measurements were averaged over 200 beats.
  • Variations were assessed at immediate, short-term, and long-term intervals.
  • The impact of noise levels (0.3 microV) on measurements was investigated.

Main Results:

  • Paired measurements of high-frequency QRS and low-amplitude signal durations showed modest correlations.
  • Significant variation was observed: up to 7% for high-frequency QRS, 20% for low-amplitude signal, and 53% for percent high-frequency.
  • Noise reduction to 0.3 microV lessened variation in percent high-frequency to 29% but did not significantly affect duration variability.

Conclusions:

  • Considerable variation exists in signal-averaged electrocardiogram measurements, particularly in high-frequency voltage.
  • Noise is a critical factor affecting the consistency of voltage measurements in the frequency domain.
  • Duration measurements are less influenced by noise compared to voltage parameters in SAECGs.