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

Decreased pulse rate01:14

Decreased pulse rate

817
Bradycardia is a medical condition in which the heart rate is slower than normal. It occurs when the heart's natural pacemaker, the sinus node, generates slower electrical impulses than the standard rhythm. In adults, bradycardia is diagnosed when the pulse rate falls below 60 beats per minute, indicating a deviation from the normal heart rate range.
There are specific risk factors that can elevate the likelihood of developing bradycardia. Advanced age is a significant factor, with...
817
Dysrhythmias IV: Characteristics of Bradyarrhythmias01:18

Dysrhythmias IV: Characteristics of Bradyarrhythmias

473
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...
473
Dysrhythmias II: Classification of Tachyarrhythmias01:28

Dysrhythmias II: Classification of Tachyarrhythmias

471
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...
471
Mechanism of Cardiac Arrhythmias01:28

Mechanism of Cardiac Arrhythmias

1.6K
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.
1.6K
Disturbances in Heart Rhythm01:29

Disturbances in Heart Rhythm

2.4K
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...
2.4K
Dysrhythmias VI: Management of Dysrhythmias01:25

Dysrhythmias VI: Management of Dysrhythmias

411
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...
411

You might also read

Related Articles

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

Sort by
Same author

A new approach to an old disease: Ageing, arrhythmogenic substrate and the role of risk-factor modification in atrial fibrillation.

Experimental physiology·2026
Same author

Distinct Exercise Response Patterns in Patients With Heart Failure With Preserved Ejection Fraction.

Journal of the American Heart Association·2026
Same author

Isolated Outlier Heart Rate Spikes in Athletes: A Signal Acknowledged, Not Missed.

European journal of preventive cardiology·2026
Same author

Risk Stratification in Aortic Stenosis: Exercise Hemodynamics to Refine Risk in Early Cardiac Damage Stages.

European heart journal. Cardiovascular Imaging·2026
Same author

Comparative performance of wearable ECG devices for rhythm monitoring in endurance athletes.

American journal of preventive cardiology·2026
Same author

Sex-Based Differences in Atrial Fibrillation: Epidemiology, Prehospital Care, Hospital Management, and Outcomes.

Journal of the American Heart Association·2026

Related Experiment Video

Updated: Jan 8, 2026

Real-Time Electrocardiogram Monitoring During Treadmill Training in Mice
04:45

Real-Time Electrocardiogram Monitoring During Treadmill Training in Mice

Published on: May 5, 2022

2.9K

Bradycardia in Athletes: Prevalence, Mechanisms, and Risks.

Paolo D'Ambrosio1,2,3, Jarne De Paepe4,5,6,7, Luke W Spencer1,2

  • 1Department of Medicine, The University of Melbourne, Parkville, VIC, Australia (P.D., L.W.S., A.M.M., M.D.F., S.J.R., P.M.K., J.M.K., A.L.G.).

Circulation
|December 18, 2025
PubMed
Summary

Endurance athletes often have sinus bradycardia, a slow heart rate, due to fitness and genetics. A lower heart rate polygenic risk score (HR-PRS) is linked to lower heart rates in athletes, suggesting genetics influence athletic performance.

Keywords:
AV blockarrhythmiasathletesbradycardiadiagnostic imagingexercisegeneticsheart rate

More Related Videos

Autonomic Function Following Concussion in Youth Athletes: An Exploration of Heart Rate Variability Using 24-hour Recording Methodology
05:48

Autonomic Function Following Concussion in Youth Athletes: An Exploration of Heart Rate Variability Using 24-hour Recording Methodology

Published on: September 21, 2018

10.5K
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

3.5K

Related Experiment Videos

Last Updated: Jan 8, 2026

Real-Time Electrocardiogram Monitoring During Treadmill Training in Mice
04:45

Real-Time Electrocardiogram Monitoring During Treadmill Training in Mice

Published on: May 5, 2022

2.9K
Autonomic Function Following Concussion in Youth Athletes: An Exploration of Heart Rate Variability Using 24-hour Recording Methodology
05:48

Autonomic Function Following Concussion in Youth Athletes: An Exploration of Heart Rate Variability Using 24-hour Recording Methodology

Published on: September 21, 2018

10.5K
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

3.5K

Area of Science:

  • Cardiology
  • Sports Medicine
  • Genetics

Background:

  • Sinus bradycardia is common in endurance athletes, attributed to physiological adaptations.
  • The genetic basis of athletic bradycardia remains largely unexplored.

Purpose of the Study:

  • To investigate the genetic contribution to bradycardia in elite endurance athletes.
  • To assess the association between a heart rate polygenic risk score (HR-PRS) and bradycardia in athletes.

Main Methods:

  • Phenotyped 465 elite endurance athletes using cardiac imaging, exercise testing, and Holter monitoring.
  • Assessed genetic susceptibility using a validated HR-PRS and compared athletes with non-athletes.
  • Compared bradycardic athletes (BAs) with non-BAs.

Main Results:

  • 38% of athletes exhibited minimum heart rates ≤40 bpm; 2% had HR ≤30 bpm.
  • Lower HR-PRS was significantly associated with lower minimum heart rates and increased odds of resting bradycardia (OR, 2.2).
  • Bradycardia and pauses were well-tolerated and not associated with adverse outcomes over 5.5 years.

Conclusions:

  • Fitness and genetic variation contribute to sinus node function in endurance athletes.
  • HR-PRS differs between athletes and non-athletes, suggesting a potential genetic determinant of athleticism.