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...

Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers

Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers

Adrenergic stimulation generally impacts cardiac rate and rhythm. Specifically, stimulation of the β-adrenoceptors triggers an increase in intracellular calcium ion influx and pacemaker currents, which may cause arrhythmias. Catecholamines like adrenaline also demonstrate β2-adrenoceptor-mediated hypokalemia, impacting cardiac action potential and disrupting the normal cardiac rhythm. Class II antiarrhythmic drugs are β-adrenoceptor antagonists or β-blockers, which indirectly block calcium...

Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers

Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers

Class IV antiarrhythmic drugs, such as verapamil and diltiazem, block calcium channels. They primarily affect the heart, slowing the conduction in calcium-dependent tissues like the SA and AV nodes. These drugs manage reentrant supraventricular tachycardia (SVT) and reduce ventricular rate in atrial flutter/fibrillation.
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...

Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers

Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers

Class III antiarrhythmic drugs are a group of medications that can prolong action potentials in the heart. They achieve this by blocking potassium channels or enhancing inward currents from sodium channels. However, these drugs have a unique property of "reverse use-dependence," which is most pronounced at slower heart rates and can lead to torsades de pointes—a specific type of arrhythmia. However, it is essential to note that excessive QT interval prolongation—a measure of the heart's...

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...

Heart Failure Drugs: β-Blockers

Heart Failure Drugs: β-Blockers

β-adrenergic antagonists, commonly known as β-blockers, block the effects of sympathetic neurotransmitters such as noradrenaline (NA) and adrenaline (ADR). They have several beneficial effects in heart failure treatment. They reduce heart rate, the force of contraction, and cardiac muscle relaxation. They also slow the atrial-ventricular conduction rate and raise the threshold for arrhythmias. The concentration of β-blockers determines their effects on bronchodilation, vasodilation, and...

You might also read

Related Articles

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

Sort by

Same author

A Farewell Message from the Retiring Editor-in-Chief.

Journal of insurance medicine (New York, N.Y.)·2024

Same author

Inside "Operation Change Agent": Mallinckrodt's Plan for Capturing the Opioid Market.

Journal of health politics, policy and law·2024

Same author

The opioid industry document archive: New directions in research on corporate political strategy.

The International journal on drug policy·2023

Same author

Attitudes towards the 'Shisha No Thanks' campaign video: Content analysis of Facebook comments.

Tobacco induced diseases·2022

Same author

Evaluation of 'Shisha No Thanks' - a co-design social marketing campaign on the harms of waterpipe smoking.

BMC public health·2022

Same author

Development and equivalence of new faces for inclusion in the Childhood Asthma Control Test (C-ACT) response scale.

Journal of patient-reported outcomes·2021

Same journal

Creating Evidence-Based Ratings and Life Expectancies Medical Impairments.

Journal of insurance medicine (New York, N.Y.)·2026

Same journal

The Smoking Dilemma: A Technical Deep Dive.

Journal of insurance medicine (New York, N.Y.)·2026

Same journal

Biological Clocks: Ready for Prime Time?

Journal of insurance medicine (New York, N.Y.)·2026

Same journal

GLP-1 Therapies and Mortality Risk: Implications for Life Insurers.

Journal of insurance medicine (New York, N.Y.)·2026

Same journal

Identifying Benzodiazepine Abuse: A Report of 3 Cases.

Journal of insurance medicine (New York, N.Y.)·2026

Same journal

Between Fear and Adoption: The AI Paradox in Medico-Legal Practice Among National Insurance Physicians.

Journal of insurance medicine (New York, N.Y.)·2026

See all related articles

Search research articles

Related Experiment Video

Updated: Jun 28, 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

"Complicated" right bundle branch block.

Ross MacKenzie¹

¹Consulting, 2261 Constance Drive, Oakville, Ontario L6J 5L8, Canada. rossmackenzieconsulting@msn.com

Journal of Insurance Medicine (New York, N.Y.)

|October 18, 2008

Summary

This summary is machine-generated.

Isolated right bundle branch block is usually benign. However, complex patterns on an electrocardiogram may indicate hidden heart disease impacting long-term survival.

More Related Videos

Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System

Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System

Published on: April 11, 2025

Rat Model of Right-Sided Cardiac Remodeling and Arrhythmia Using Pulmonary Artery Banding

Rat Model of Right-Sided Cardiac Remodeling and Arrhythmia Using Pulmonary Artery Banding

Published on: August 30, 2024

Related Experiment Videos

Last Updated: Jun 28, 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

Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System

Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System

Published on: April 11, 2025

Rat Model of Right-Sided Cardiac Remodeling and Arrhythmia Using Pulmonary Artery Banding

Rat Model of Right-Sided Cardiac Remodeling and Arrhythmia Using Pulmonary Artery Banding

Published on: August 30, 2024

Area of Science:

Cardiology
Electrophysiology
Diagnostic Medicine

Background:

Right bundle branch block (RBBB) is often considered a benign electrocardiographic finding.
Its significance can change when associated with other cardiac abnormalities.

Observation:

The study focuses on "electrocardiographically-complicated" RBBB.
This specific pattern warrants further medical evaluation.

Findings:

"Electrocardiographically-complicated" RBBB suggests the potential for underlying, undiagnosed structural heart disease.
This finding is crucial for assessing patient prognosis.

Implications:

Medical directors should be alerted to occult heart disease in patients with complicated RBBB.
Early detection of associated heart conditions can improve long-term survival outcomes.