Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Electrocardiogram

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...

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

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...

Cardiac Action Potential

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

Mechanism of Cardiac Arrhythmias

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.

Electrophysiology of Normal Cardiac Rhythm

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...

Disturbances in Heart Rhythm

Disturbances in Heart Rhythm

Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias.
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...

You might also read

Related Articles

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

Sort by

Same author

Acta medica portuguesa·2022

Same author

Delayed diagnosis of occult phosphaturic mesenchymal tumor in the foot.

Radiology case reports·2021

Same author

Validation of the Ottawa ankle rules: Strategies for increasing specificity.

Injury·2021

Same author

Complex proximal humerus fracture with associated glenoid fracture - Solution with reverse shoulder arthroplasty and glenoid fixation.

Trauma case reports·2020

Same author

Unusual type A aortic dissection.

Revista portuguesa de cardiologia : orgao oficial da Sociedade Portuguesa de Cardiologia = Portuguese journal of cardiology : an official journal of the Portuguese Society of Cardiology·2012

Search research articles

Related Experiment Video

Updated: Mar 29, 2026

Real-Time Electrocardiogram Monitoring During Treadmill Training in Mice

Real-Time Electrocardiogram Monitoring During Treadmill Training in Mice

Published on: May 5, 2022

Benign and pathological electrocardiographic changes in athletes.

Marino Machado¹, Manuel Vaz Silva²

¹Faculdade de Medicina, Universidade do Porto, Porto, Portugal.

Revista Portuguesa De Cardiologia : Orgao Oficial Da Sociedade Portuguesa De Cardiologia = Portuguese Journal of Cardiology : an Official Journal of the Portuguese Society of Cardiology

|December 9, 2015

Summary

Sudden cardiac death in athletes is a concern. This review differentiates normal athlete

Keywords:

Athletes Atletas Critérios de Seattle Electrocardiogram Eletrocardiograma Morte súbita cardíaca Rastreio Screening Seattle criteria Sudden cardiac death

More Related Videos

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

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

Effects of Different Connection Modes of Electroacupuncture on Electrocardiogram and Nerve Discharge in Rats

Effects of Different Connection Modes of Electroacupuncture on Electrocardiogram and Nerve Discharge in Rats

Published on: January 3, 2025

Related Experiment Videos

Last Updated: Mar 29, 2026

Real-Time Electrocardiogram Monitoring During Treadmill Training in Mice

Real-Time Electrocardiogram Monitoring During Treadmill Training in Mice

Published on: May 5, 2022

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

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

Effects of Different Connection Modes of Electroacupuncture on Electrocardiogram and Nerve Discharge in Rats

Effects of Different Connection Modes of Electroacupuncture on Electrocardiogram and Nerve Discharge in Rats

Published on: January 3, 2025

Area of Science:

Cardiology
Sports Medicine
Exercise Physiology

Background:

Sudden cardiac death (SCD) is the leading cause of death in athletes during sports.
Athlete's heart, a result of regular exercise, causes cardiac remodeling and electrocardiogram (ECG) changes.
Distinguishing physiological ECG changes from those indicating underlying cardiac disease is crucial for preventing SCD.

Purpose of the Study:

To review current data on benign and pathological ECG changes in athletes.
To critically analyze the Seattle criteria for ECG classification in athletes.
To compare the Seattle criteria with previous guidelines and recent studies.

Main Methods:

Literature review of recent studies on ECGs in athletes.
Analysis of the Seattle criteria and comparison with other guidelines.
Examination of pre-participation screening programs, including US and European approaches.

Main Results:

Discussion of the latest data on ECG patterns in athletes.
Comparison of the sensitivity, specificity, and cost-effectiveness of ECG screening.
Analysis of gender, ethnicity, and age differences in ECG findings.

Conclusions:

There is an urgent need for clear ECG criteria to guide sports participation.
The Seattle criteria represent a recent advancement in classifying athlete ECGs.
Further research is needed to optimize ECG screening protocols for athletes.