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

Dysrhythmias IV: Characteristics of Bradyarrhythmias

Dysrhythmias IV: Characteristics of Bradyarrhythmias

Bradyarrhythmias are cardiac rhythm disorders characterized by a slower-than-normal heart rate, typically defined as fewer than 60 beats per minute. Some of which are discussed here:Sinus BradycardiaSinus bradycardia presents a heart rate lower than 60 beats per minute, with a regular rhythm originating from the SA node. The ECG typically shows normal P waves preceding each QRS complex, a normal PR interval (0.12 to 0.20 seconds), and a normal QRS duration (0.06 to 0.10 seconds).First-Degree AV...

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...

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

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...

Cardiomyopathy III: Hypertrophic Cardiomyopathy

Cardiomyopathy III: Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy, or HCM, is an autosomal dominant genetic disorder characterized by asymmetric left ventricular hypertrophy without ventricular dilation. It is more common in men and is typically diagnosed in young, athletic adults.EtiologyHCM is primarily genetic and is caused by mutations in genes encoding sarcomeric proteins. Researchers have identified over 1400 mutations across at least 11 different genes. Among these, the most frequently occurring mutations are found in the...

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.

You might also read

Related Articles

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

Sort by

Same author

Trends in stroke risk among female and male patients with atrial fibrillation: a 20-year population-based cohort study.

Heart rhythm·2026

Same author

Primary Care Physicians' Interpretation of Smartwatch ECGs in Atrial Fibrillation: A Cross-Sectional Study.

JACC. Advances·2026

Same author

Rural-urban disparities in atrial fibrillation-related diagnostic testing and medical procedures in Canada†.

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

Determinants of ECG misdiagnosis of atrial fibrillation or flutter in the emergency department and their clinical implications: results from a single-center observational study.

BMC emergency medicine·2026

Same author

The Human Factor: Physicians' Unbiased Interpretation of Atrial Fibrillation in the Emergency Department.

Pacing and clinical electrophysiology : PACE·2026

Same author

Outcomes of individual DOACs vs. VKAs in AF patients with frailty: a systematic review and meta-analysis.

Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing·2026

Same journal

Systematic multi-domain screening of lead-specific electrocardiographic features associated with sudden cardiac death.

Journal of electrocardiology·2026

Same journal

The need to measure electrical synchrony - Assessment of electrical synchrony and its utility. Synchromax in real life.

Journal of electrocardiology·2026

Same journal

An assessment of intern doctors' experiences of undergraduate education in electrocardiogram interpretation.

Journal of electrocardiology·2026

Same journal

Feasibility and efficacy of left bundle branch area pacing guided by modified chest lead 1.

Journal of electrocardiology·2026

Same journal

Spatial proximity or vector orientation? Re-evaluating ECG interpretation in anterior myocardial infarction using cardiac magnetic resonance.

Journal of electrocardiology·2026

Same journal

Pacing spikes without visible QRS complexes: Failure to capture?

Journal of electrocardiology·2026

See all related articles

Search research articles

Related Experiment Video

Updated: Feb 24, 2026

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing

Published on: December 11, 2017

Alternating trifascicular block and cardiac memory.

Asaf Danon¹, Mohammed Shurrab²

¹Department of Cardiology, Carmel Medical Center, Haifa, Israel.

Journal of Electrocardiology

|August 14, 2017

Summary

This summary is machine-generated.

A 70-year-old woman experienced worsening atrioventricular (AV) block with exercise due to an alternating trifascicular conduction pattern. This case highlights T wave memory changes and strategies for managing exercise-induced AV block.

Keywords:

Alternating block Atrioventricular block Exercise induced AV block T wave memory

More Related Videos

Optimization of Transesophageal Atrial Pacing to Assess Atrial Fibrillation Susceptibility in Mice

Optimization of Transesophageal Atrial Pacing to Assess Atrial Fibrillation Susceptibility in Mice

Published on: June 29, 2022

Ablation of Ischemic Ventricular Tachycardia Using a Multipolar Catheter and 3-dimensional Mapping System for High-density Electro-anatomical Reconstruction

Ablation of Ischemic Ventricular Tachycardia Using a Multipolar Catheter and 3-dimensional Mapping System for High-density Electro-anatomical Reconstruction

Published on: January 31, 2019

Related Experiment Videos

Last Updated: Feb 24, 2026

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing

Published on: December 11, 2017

Optimization of Transesophageal Atrial Pacing to Assess Atrial Fibrillation Susceptibility in Mice

Optimization of Transesophageal Atrial Pacing to Assess Atrial Fibrillation Susceptibility in Mice

Published on: June 29, 2022

Ablation of Ischemic Ventricular Tachycardia Using a Multipolar Catheter and 3-dimensional Mapping System for High-density Electro-anatomical Reconstruction

Ablation of Ischemic Ventricular Tachycardia Using a Multipolar Catheter and 3-dimensional Mapping System for High-density Electro-anatomical Reconstruction

Published on: January 31, 2019

Area of Science:

Cardiology
Electrophysiology
Internal Medicine

Background:

Atrioventricular (AV) block is a condition affecting the heart's electrical signaling.
Trifascicular conduction patterns can predispose individuals to complex arrhythmias.
Exercise can unmask or exacerbate underlying cardiac conduction abnormalities.

Observation:

A 70-year-old woman presented with dyspnea on exertion and an alternating trifascicular conduction pattern.
The conduction pattern worsened during exercise, leading to atrioventricular block.
At rest, the alternating conduction was associated with significant T wave abnormalities.

Findings:

The case demonstrates exercise-induced atrioventricular block secondary to an alternating trifascicular conduction pattern.
T wave memory changes were observed, linked to the dynamic alterations in cardiac conduction.
The interplay between conduction system disease and exertion-related hemodynamic changes is highlighted.

Implications:

Understanding T wave memory mechanisms is crucial for diagnosing and managing conduction disorders.
Effective management strategies for exercise-induced AV block are essential for patient prognosis.
This case underscores the importance of thorough cardiac evaluation in patients with exertional symptoms and conduction abnormalities.