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

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...
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 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...
ECG Interpretation of Arrhythmias I: Sinus Arrhythmias01:16

ECG Interpretation of Arrhythmias I: Sinus Arrhythmias

Arrhythmias are disturbances in the heart's rhythm that lead to abnormal heartbeats. These irregularities can originate from different parts of the heart and are classified based on their origin and nature.
Types of Arrhythmias
Sinus Node Arrhythmias
Sinus Bradycardia: Originating from the sinoatrial (SA) node, sinus bradycardia involves slower impulses, resulting in a heart rate of less than 60 beats per minute (bpm). Causes include sleep, vagal stimulation, beta-blockers, hypothyroidism, and...
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...
Quartile01:15

Quartile

Quartiles are numbers that separate the data into quarters. Quartiles may or may not be part of the data. To find the quartiles, first, find the median or second quartile. The first quartile, Q1, is the middle value of the lower half of the data, and the third quartile, Q3, is the middle value, or median, of the upper half of the data. To get the idea, consider the same data set:
1; 1; 2; 2; 4; 6; 6.8; 7.2; 8; 8.3; 9; 10; 10; 11.5
The median or second quartile is seven. The lower half of the...

You might also read

Related Articles

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

Sort by
Same author

Abstracts Association Tunisienne de Médecine Néonatale (ATMN).

La Tunisie medicale·2026
Same author

[Knowledge of breastfeeding among mothers before maternity discharge].

Gynecologie, obstetrique, fertilite & senologie·2021
Same author

Getting to the <em>heart</em> of the matter: diagnostic tools and therapeutic approach to cardiac involvement in Behçet syndrome A Tunisian case series.

Reumatismo·2021
Same author

Water footprint and economic water productivity assessment of eight dairy cattle farms based on field measurement.

Animal : an international journal of animal bioscience·2019
Same author

Increased docosahexaenoic acid and n-3 polyunsaturated fatty acids in milk from mothers of small for gestational age preterm infants.

Prostaglandins, leukotrienes, and essential fatty acids·2018
Same author

Water footprint assessment of sheep farming systems based on farm survey data.

Animal : an international journal of animal bioscience·2018
Same journal

[Study of Sleep Apnea Syndrome in Patients with Chronic Heart Failure in the Cardiology Department at Yalgado Ouédraogo teaching hospital in 2024 and 2025].

Annales de cardiologie et d'angeiologie·2026
Same journal

[Impact of knowledge and practices of hygieno-dietetical measures in hypertensive people at the Abidjan cardiology institute].

Annales de cardiologie et d'angeiologie·2026
Same journal

[Correlation between carotid atheroma and DAS28 gamma GT score in rheumatoid arthritis in an African black population].

Annales de cardiologie et d'angeiologie·2026
Same journal

[Dobutamine stress echocardiography: Appropriateness of indications and protocol compliance. A single-centre report].

Annales de cardiologie et d'angeiologie·2026
Same journal

[Post-COVID postural orthostatic tachycardia syndrome: Documentation of a hyperadrenergic phenotype by comprehensive autonomic testing].

Annales de cardiologie et d'angeiologie·2026
Same journal

Urban-rural disparities in hypertension prevalence, screening, and control in South Kivu Province, eastern Democratic Republic of the Congo.

Annales de cardiologie et d'angeiologie·2026
See all related articles

Related Experiment Video

Updated: Jun 4, 2026

Methods for ECG Evaluation of Indicators of Cardiac Risk, and Susceptibility to Aconitine-induced Arrhythmias in Rats Following Status Epilepticus
08:28

Methods for ECG Evaluation of Indicators of Cardiac Risk, and Susceptibility to Aconitine-induced Arrhythmias in Rats Following Status Epilepticus

Published on: April 5, 2011

[The QT interval: standardization, limits and interpretation].

S Ouali1, H Ben Salem, R Gribaa

  • 1Service de cardiologie, hôpital Sahloul, route Ceinture, cité Sahloul, Sousse, Tunisia. sanaouali@hotmail.fr

Annales De Cardiologie Et D'Angeiologie
|February 1, 2011
PubMed
Summary
This summary is machine-generated.

Analyzing ventricular repolarization, specifically the QT interval, is crucial for patient safety. This review discusses QT interval measurement, interpretation, and adjustments for factors like heart rate, age, and gender to improve clinical analysis.

More Related Videos

In Vivo Surface Electrocardiography for Adult Zebrafish
09:13

In Vivo Surface Electrocardiography for Adult Zebrafish

Published on: August 1, 2019

Related Experiment Videos

Last Updated: Jun 4, 2026

Methods for ECG Evaluation of Indicators of Cardiac Risk, and Susceptibility to Aconitine-induced Arrhythmias in Rats Following Status Epilepticus
08:28

Methods for ECG Evaluation of Indicators of Cardiac Risk, and Susceptibility to Aconitine-induced Arrhythmias in Rats Following Status Epilepticus

Published on: April 5, 2011

In Vivo Surface Electrocardiography for Adult Zebrafish
09:13

In Vivo Surface Electrocardiography for Adult Zebrafish

Published on: August 1, 2019

Area of Science:

  • Cardiology
  • Electrophysiology
  • Medical Diagnostics

Context:

  • Ventricular repolarization analysis, particularly the QT interval, is clinically significant but challenging.
  • Conventional methods rely on T wave axis and QT interval duration, with risks including torsades de pointes from QT prolongation.
  • Existing electrocardiogram (ECG) reference ranges are outdated and do not account for diverse global populations.

Purpose:

  • To review current methodologies for measuring and interpreting the QT interval.
  • To address the influence of various factors on QT interval duration.
  • To discuss the necessity of adjusting QT interval measurements for rate, age, gender, and QRS duration.

Summary:

  • This review examines the complexities of ventricular repolarization analysis, focusing on the QT interval.
  • It highlights factors influencing QT interval prolongation, such as drugs, electrolyte imbalances, and ischemia, and the associated risk of torsades de pointes.
  • The paper emphasizes the need for updated reference data and discusses adjustments for rate, age, gender, and QRS duration.

Impact:

  • Improved accuracy in QT interval assessment for better clinical decision-making.
  • Enhanced understanding of factors affecting ventricular repolarization.
  • Potential for refined diagnostic criteria and risk stratification in cardiovascular medicine.