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

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...

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...

Dysrhythmias II: Classification of Tachyarrhythmias

Dysrhythmias II: Classification of Tachyarrhythmias

Tachyarrhythmias are a type of dysrhythmia where the heart rate exceeds 100 beats per minute. Here are some common types of tachyarrhythmias:Sinus TachycardiaSinus tachycardia originates from increased impulses from the sinus node, leading to an elevated heart rate. It is often triggered by stress, fever, or exercise.Patients may experience palpitations, a sensation of a racing heart, dizziness, and chest discomfort.Causes and Risk Factors: Common causes include physical exertion, emotional...

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.

Dysrhythmias VI: Management of Dysrhythmias

Dysrhythmias VI: Management of Dysrhythmias

Dysrhythmia management involves a multifaceted approach, incorporating pharmacological treatments, medical procedures, surgical interventions, lifestyle modifications, and patient education.Pharmacological ManagementAntiarrhythmic Drugs:Class I (Sodium Channel Blockers): This class includes quinidine and procainamide, which reduce the speed of impulse conduction in the heart, stabilize the cardiac membrane, and control arrhythmias. Quinidine and procainamide are Class IA agents that prolong the...

Dysrhythmias III: Characteristics of Dysrhythmias

Dysrhythmias III: Characteristics of Dysrhythmias

Dysrhythmias, also known as arrhythmias, are irregular heart rhythms that result from abnormal electrical activity in the heart, affecting its ability to circulate blood efficiently. Tachyarrhythmias, a subset of dysrhythmias, are characterized by abnormally fast heart rates exceeding 100 beats per minute. Here are some types of tachyarrhythmias with their distinct ECG features:Sinus Tachycardia:Sinus tachycardia presents a regular heart rhythm with an increased rate of 101-180 beats per minute.

You might also read

Related Articles

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

Sort by

Same author

Increased Ca<sup>2+</sup> Sequestration by the Sarco-/Endoplasmic Reticulum in Cardiac Purkinje Cells After Myocardial Infarction.

Cells·2026

Same author

Remodeling of sarcoplasmic reticulum Ca<sup>2+</sup> uptake in cardiac Purkinje cells after ischemic myocardial infarction in various large mammalian species and humans.

American journal of physiology. Cell physiology·2025

Same author

Diagnosis and Management of Complex Reentrant Arrhythmias Involving the His-Purkinje System.

Arrhythmia & electrophysiology review·2021

Same author

Structure and function of the ventricular tachycardia isthmus.

Heart rhythm·2021

Same author

The Interaction Between Na<sup>+</sup> and Ca<sup>2+</sup> Inward Currents in Cardiac Propagation.

Circulation research·2020

Same author

Autonomic modulation of sinoatrial node: Role of pacemaker current and calcium sensitive adenylyl cyclase isoforms.

Progress in biophysics and molecular biology·2020

Search research articles

Related Experiment Video

Updated: Jul 16, 2026

Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation

Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation

Published on: February 26, 2013

Triggered activity and atrial fibrillation.

Andrew L Wit¹, Penelope A Boyden

¹Department of Pharmacology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.

|March 6, 2007

Summary

Electrical activity in thoracic veins, like the pulmonary veins, can initiate and sustain atrial fibrillation. This review focuses on triggered activity as a potential mechanism driving this condition.

Area of Science:

Cardiology
Electrophysiology
Cardiac Arrhythmias

Background:

Atrial fibrillation (AF) is often initiated by electrical impulses originating in thoracic veins.
Pulmonary veins, vena cavae, coronary sinus, and ligament of Marshall are implicated in AF initiation and perpetuation.

Purpose of the Study:

To review evidence supporting triggered activity as a mechanism for AF initiation and perpetuation in thoracic veins.

Main Methods:

Review of in vivo and in vitro studies investigating mechanisms of impulse initiation in thoracic veins.
Focus on data related to triggered activity.

Main Results:

Multiple thoracic veins contribute to AF initiation and perpetuation.
Triggered activity is a proposed mechanism for AF generation in these veins, alongside automaticity and reentry.

More Related Videos

The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation

The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation

Published on: February 28, 2012

High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation

High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation

Published on: July 29, 2011

Related Experiment Videos

Last Updated: Jul 16, 2026

Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation

Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation

Published on: February 26, 2013

The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation

The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation

Published on: February 28, 2012

High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation

High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation

Published on: July 29, 2011

Conclusions:

Triggered activity is a significant potential mechanism for the initiation and perpetuation of atrial fibrillation originating from thoracic veins.
Further research is needed to definitively elucidate the precise mechanisms of impulse initiation in these veins.