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

Conduction System of the Heart01:19

Conduction System of the Heart

13.7K
Autorhythmicity is a term that refers to the heart's inherent ability to generate electrical signals and instigate muscle contractions. This self-regulating conduction system within the heart consists of two key components: the pacemaker cells and specialized conducting cells.
The pacemaker cells are located in two primary nodes: the sinoatrial (SA) node and the atrioventricular (AV) node. The SA node pacemaker cells can autonomously depolarize, triggering an action potential that leads to the...
13.7K
Conduction System of the Heart01:20

Conduction System of the Heart

6.1K
The cardiac conduction system produces and transmits electrical impulses that prompt myocardial contraction, ensuring efficient heart function. This intricate system ensures that the heart beats in a coordinated and efficient manner, beginning with the atria and then the ventricles. The conduction system optimizes cardiac output by maintaining this precise sequence, which is crucial for adequate blood circulation.
This system relies on the unique properties of nodal and Purkinje cells:...
6.1K
ECG Interpretation of Arrhythmias I: Sinus Arrhythmias01:16

ECG Interpretation of Arrhythmias I: Sinus Arrhythmias

1.2K
Arrhythmias are disturbances in the heart's rhythm that lead to abnormal heartbeats. These irregularities can originate from different parts of the heart and are classified based on their origin and nature.
Types of Arrhythmias
Sinus Node Arrhythmias
Sinus Bradycardia: Originating from the sinoatrial (SA) node, sinus bradycardia involves slower impulses, resulting in a heart rate of less than 60 beats per minute (bpm). Causes include sleep, vagal stimulation, beta-blockers, hypothyroidism,...
1.2K
Dysrhythmias II: Classification of Tachyarrhythmias01:28

Dysrhythmias II: Classification of Tachyarrhythmias

735
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...
735
Dysrhythmias III: Characteristics of Dysrhythmias01:29

Dysrhythmias III: Characteristics of Dysrhythmias

711
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...
711
Dysrhythmias IV: Characteristics of Bradyarrhythmias01:18

Dysrhythmias IV: Characteristics of Bradyarrhythmias

788
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...
788

You might also read

Related Articles

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

Sort by
Same author

Large-scale screening studies for atrial fibrillation - is it worth the effort?

Journal of internal medicine·2021
Same author

The challenges and possibilities of public access defibrillation.

Journal of internal medicine·2018
Same author

All-cause and cardiovascular mortality risk after surgery versus radioiodine treatment for hyperthyroidism.

The British journal of surgery·2017
Same author

Drones may be used to save lives in out of hospital cardiac arrest due to drowning.

Resuscitation·2017
Same author

Unmanned aerial vehicles (drones) in out-of-hospital-cardiac-arrest.

Scandinavian journal of trauma, resuscitation and emergency medicine·2016
Same author

Alternative to the transvenous approach in pediatric pacing - long-term experiences with bipolar epicardial pacing leads.

Herzschrittmachertherapie & Elektrophysiologie·2016
Same journal

Great debate: medical treatment of heart failure with reduced ejection fraction will rely on four foundational drugs.

European heart journal·2026
Same journal

The surgical collateralization theory: has the beautiful hypothesis been killed by the ugly facts?

European heart journal·2026
Same journal

Beyond single measurement: additional considerations for high-sensitivity C-reactive protein in cardiovascular risk prediction.

European heart journal·2026
Same journal

Brain mineralocorticoid receptor activation and antagonism in heart failure with preserved ejection fraction: a hypothesis.

European heart journal·2026
Same journal

Myths and misconceptions about high-sensitivity C-reactive protein as a marker of residual inflammatory risk.

European heart journal·2026
Same journal

Vascular Ehlers-Danlos syndrome: should we treat asymptomatic patients?

European heart journal·2026
See all related articles

Related Experiment Video

Updated: May 5, 2026

Microelectrode Array Recording of Sinoatrial Node Firing Rate to Identify Intrinsic Cardiac Pacemaking Defects in Mice
09:20

Microelectrode Array Recording of Sinoatrial Node Firing Rate to Identify Intrinsic Cardiac Pacemaking Defects in Mice

Published on: July 5, 2021

2.7K

Atrial rate-responsive pacing in sinus node disease.

M Rosenqvist1, C Arén, B E Kristensson

  • 1Dept of Medicine, Karolinska Institute, Huddinge University Hospital, Sweden.

European Heart Journal
|June 1, 1990
PubMed
Summary
This summary is machine-generated.

Atrial rate-responsive pacing (AAI-R) effectively improves exercise capacity in patients with sinus node disease (SND) and chronotropic incompetence. This pacing mode enhances maximum heart rate and exercise duration compared to conventional AAI pacing.

More Related Videos

Transesophageal Atrial Burst Pacing for Atrial Fibrillation Induction in Rats
05:12

Transesophageal Atrial Burst Pacing for Atrial Fibrillation Induction in Rats

Published on: February 14, 2022

3.1K
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

2.9K

Related Experiment Videos

Last Updated: May 5, 2026

Microelectrode Array Recording of Sinoatrial Node Firing Rate to Identify Intrinsic Cardiac Pacemaking Defects in Mice
09:20

Microelectrode Array Recording of Sinoatrial Node Firing Rate to Identify Intrinsic Cardiac Pacemaking Defects in Mice

Published on: July 5, 2021

2.7K
Transesophageal Atrial Burst Pacing for Atrial Fibrillation Induction in Rats
05:12

Transesophageal Atrial Burst Pacing for Atrial Fibrillation Induction in Rats

Published on: February 14, 2022

3.1K
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

2.9K

Area of Science:

  • Cardiology
  • Biomedical Engineering
  • Electrophysiology

Background:

  • Sinus node disease (SND) can impair the heart's ability to increase rate during exertion.
  • Patients with SND and chronotropic incompetence may not achieve adequate heart rate response during physical activity.
  • Atrial rate-responsive pacing (AAI-R) is an option for managing these patients.

Purpose of the Study:

  • To evaluate the efficacy of atrial rate-responsive pacing (AAI-R) in patients with sinus node disease (SND).
  • To compare exercise performance between AAI-R and conventional atrial inhibited pacing (AAI) in SND patients with chronotropic incompetence.

Main Methods:

  • Implantation of 40 AAI-R systems in SND patients with activity-sensing pulse generators.
  • Inclusion criteria: intraoperative AV nodal block cycle-length > 100 beats/min.
  • Randomized double-blind crossover study comparing AAI-R and AAI pacing in 12 patients with chronotropic incompetence.

Main Results:

  • AAI-R pacing demonstrated a significantly higher maximum heart rate during exercise (120 ± 1 bpm) compared to AAI pacing (97 ± 21 bpm).
  • Average exercise time increased from 11.2 ± 2 min with AAI pacing to 13.4 ± 3 min with AAI-R pacing.
  • No persistent AV-block or chronic atrial fibrillation observed; one transient asymptomatic 2:1 AV-block during sleep.

Conclusions:

  • Atrial rate-responsive pacing (AAI-R) is a safe and effective pacing mode for SND patients.
  • AAI-R significantly improves exercise heart rate and duration in patients with chronotropic incompetence.
  • AAI pacing should be considered for patients with SND and chronotropic incompetence.