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

Dysrhythmias IV: Characteristics of Bradyarrhythmias01:18

Dysrhythmias IV: Characteristics of Bradyarrhythmias

264
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...
264
Disturbances in Heart Rhythm01:29

Disturbances in Heart Rhythm

1.8K
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...
1.8K
ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias01:25

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

228
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...
228
Dysrhythmias III: Characteristics of Dysrhythmias01:29

Dysrhythmias III: Characteristics of Dysrhythmias

210
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...
210
Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers01:12

Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers

1.5K
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...
1.5K
Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers01:24

Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers

1.1K
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...
1.1K

You might also read

Related Articles

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

Sort by
Same author

LGBTQ+ inclusion in local authority public health: a review of needs assessments in England.

Perspectives in public health·2026
Same author

Echocardiographic predictors of persistent left heart enlargement in dogs undergoing surgical mitral valve repair.

Journal of veterinary cardiology : the official journal of the European Society of Veterinary Cardiology·2026
Same author

Retrospective review of the use of hydrochlorothiazide in dogs with myxomatous mitral valve disease and refractory congestive heart failure (American College of Veterinary Cardiology stage D).

Journal of veterinary cardiology : the official journal of the European Society of Veterinary Cardiology·2025
Same author

Rapid onset calcareous degeneration in a penetrating keratoplasty graft after denosumab injection.

Journal francais d'ophtalmologie·2025
Same author

Transient atrial fibrillation in dogs with degenerative mitral valve disease: eight cases (2020-2024).

The Journal of small animal practice·2025
Same author

Prevalence of cardiomyopathy and cardiac mortality in a colony of non-purebred cats in New Zealand.

New Zealand veterinary journal·2024

Related Experiment Video

Updated: Nov 4, 2025

Optimization of Transesophageal Atrial Pacing to Assess Atrial Fibrillation Susceptibility in Mice
08:05

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

Published on: June 29, 2022

3.1K

Paroxysmal high-grade second-degree and persistent third-degree atrioventricular block in cats.

I Spalla1, G W Smith2, Y-M Chang2

  • 1Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, AL9 7TA, United Kingdom; Ospedale Veterinario San Francesco, via Isaac Newton 2, 20148 Milano, Italy.

Journal of Veterinary Cardiology : the Official Journal of the European Society of Veterinary Cardiology
|May 29, 2021
PubMed
Summary

Atrioventricular block (AVB) in cats can be persistent or paroxysmal, with most experiencing good long-term survival. Epicardial pacemaker implantation (EPI) effectively resolved clinical signs in affected feline patients.

Keywords:
ArrhythmiaEpicardial pacemakerFelineSurvival

More Related Videos

Electrophysiological Assessment of Murine Atria with High-Resolution Optical Mapping
08:19

Electrophysiological Assessment of Murine Atria with High-Resolution Optical Mapping

Published on: February 22, 2018

10.2K
Programmed Electrical Stimulation in Mice
07:29

Programmed Electrical Stimulation in Mice

Published on: May 26, 2010

20.9K

Related Experiment Videos

Last Updated: Nov 4, 2025

Optimization of Transesophageal Atrial Pacing to Assess Atrial Fibrillation Susceptibility in Mice
08:05

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

Published on: June 29, 2022

3.1K
Electrophysiological Assessment of Murine Atria with High-Resolution Optical Mapping
08:19

Electrophysiological Assessment of Murine Atria with High-Resolution Optical Mapping

Published on: February 22, 2018

10.2K
Programmed Electrical Stimulation in Mice
07:29

Programmed Electrical Stimulation in Mice

Published on: May 26, 2010

20.9K

Area of Science:

  • Veterinary Cardiology
  • Feline Medicine

Background:

  • Atrioventricular block (AVB) is recognized in cats, presenting as either paroxysmal high-grade second-degree or persistent third-degree.
  • This study investigates the clinical presentation, diagnostic findings, comorbidities, and outcomes of cats with AVB.

Purpose of the Study:

  • To document the presentation, echocardiographic data, comorbidities, and outcomes of cats with atrioventricular block (AVB).
  • To evaluate the efficacy and complications of epicardial pacemaker implantation (EPI) in cats with AVB.

Main Methods:

  • Retrospective study of 64 cats diagnosed with persistent third-degree or paroxysmal high-grade AVB.
  • Analysis included patient history, echocardiographic data, comorbidities, and survival data. Statistical methods included non-parametric testing, Kaplan-Meier curves, and Cox proportional hazard testing.

Main Results:

  • Of 64 cats, 67% had persistent AVB and 33% had paroxysmal AVB. 74% were referred for cardiac complaints.
  • Echocardiographic abnormalities were present in 63% of cats, and 20% presented with congestive heart failure. 70% had comorbidities.
  • Fifteen cats underwent EPI, with 12 showing immediate sign resolution. Median survival time was 799 days; heart failure at presentation was an independent risk factor for cardiac death.

Conclusions:

  • Outcome for cats with AVB is variable, but most achieve good medium- to long-term survival.
  • Cardiac death occurred in a minority of cases.
  • Epicardial pacemaker implantation (EPI) proved effective in alleviating clinical signs associated with AVB in cats.