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

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...
Cardiovascular System Abnormal Findings I: Inspection and Palpation01:29

Cardiovascular System Abnormal Findings I: Inspection and Palpation

In a cardiovascular examination, inspection and palpation are crucial for identifying abnormalities.
Abnormal findings observed during an inspection
ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias01:25

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

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...
Dysrhythmias III: Characteristics of Dysrhythmias01:29

Dysrhythmias III: Characteristics of Dysrhythmias

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 minute.
Disturbances in Heart Rhythm01:29

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...
Aortic Regurgitation I: Introduction01:15

Aortic Regurgitation I: Introduction

IntroductionAortic regurgitation is characterized by the backward flow of blood from the aorta into the left ventricle during diastole and arises from the improper closure of the aortic valve. This condition results in left ventricular volume overload and can stem from both acute and chronic etiologies, each contributing uniquely to the disease's progression and symptomatology.Acute and Chronic CausesAcute aortic regurgitation often results from events that suddenly impair the integrity of the...

You might also read

Related Articles

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

Sort by
Same author

Asia Pacific Heart Rhythm Society (APHRS) scientific statement on stroke prevention strategies in patients with device-detected atrial fibrillation: the 4S-DDAF approach.

The Lancet regional health. Western Pacific·2026
Same author

Cardiac implantable electronic device upgrades and downgrades: a Clinical Consensus Statement of the European Heart Rhythm Association (EHRA) of the ESC, the Asia Pacific Heart Rhythm Association (APHRS), Canadian Heart Rhythm Society (CHRS), Heart Rhythm Society (HRS), and the Latin American Heart Rhythm Society (LAHRS).

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·2025
Same author

Development of three-step holistic care pathways to detect and manage comorbidities in patients with atrial fibrillation: the Horizon 2020 EHRA-PATHS consortium.

European heart journal open·2025
Same author

Adverse Effect of Ventricular Rate Regularization Pacing in Biventricular Cardiac Resynchronization Therapy.

Journal of cardiovascular electrophysiology·2025
Same author

Impacts of viral respiratory infections on segments of fatal out-of-hospital cardiac arrests.

Postgraduate medical journal·2025
Same author

Postmortem Removal of Submuscularly Placed Subcutaneous Implantable Cardioverter Defibrillator in the Obese.

Pacing and clinical electrophysiology : PACE·2025

Related Experiment Video

Updated: May 28, 2026

Interventional Diagnostic Procedure: A Practical Guide for the Assessment of Coronary Vascular Function
10:28

Interventional Diagnostic Procedure: A Practical Guide for the Assessment of Coronary Vascular Function

Published on: March 15, 2022

Abnormal vascular function in PR-interval prolongation.

Yap-Hang Chan1, Chung-Wah Siu, Kai-Hang Yiu

  • 1Cardiology Division, Department of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong, China.

Clinical Cardiology
|October 14, 2011
PubMed
Summary

PR interval length, even within normal limits, is linked to poorer vascular function. This suggests an early vascular dysfunction stage in PR prolongation, potentially explaining increased cardiovascular risk.

More Related Videos

Continuous Venous-Arterial Doppler Ultrasound During a Preload Challenge
09:32

Continuous Venous-Arterial Doppler Ultrasound During a Preload Challenge

Published on: January 20, 2023

Noninvasive Determination of Vortex Formation Time Using Transesophageal Echocardiography During Cardiac Surgery
04:48

Noninvasive Determination of Vortex Formation Time Using Transesophageal Echocardiography During Cardiac Surgery

Published on: November 28, 2018

Related Experiment Videos

Last Updated: May 28, 2026

Interventional Diagnostic Procedure: A Practical Guide for the Assessment of Coronary Vascular Function
10:28

Interventional Diagnostic Procedure: A Practical Guide for the Assessment of Coronary Vascular Function

Published on: March 15, 2022

Continuous Venous-Arterial Doppler Ultrasound During a Preload Challenge
09:32

Continuous Venous-Arterial Doppler Ultrasound During a Preload Challenge

Published on: January 20, 2023

Noninvasive Determination of Vortex Formation Time Using Transesophageal Echocardiography During Cardiac Surgery
04:48

Noninvasive Determination of Vortex Formation Time Using Transesophageal Echocardiography During Cardiac Surgery

Published on: November 28, 2018

Area of Science:

  • Cardiovascular Physiology
  • Vascular Biology
  • Electrocardiography

Background:

  • Mechanisms linking PR-interval prolongation to cardiovascular risk remain unclear.
  • PR prolongation is associated with adverse cardiovascular outcomes, including atrial fibrillation.
  • This study investigates the relationship between PR interval and vascular function markers.

Purpose of the Study:

  • To explore the association between PR interval length and vascular function in healthy individuals.
  • To test the hypothesis that subclinical vascular changes mediate the link between PR prolongation and cardiovascular risk.

Main Methods:

  • 88 healthy subjects (mean age 57.5 years) underwent ECG for PR interval measurement.
  • Vascular function assessed noninvasively using flow-mediated dilation (FMD) and pulse wave velocity (PWV).
  • Subjects had no history of cardiovascular disease or diabetes.

Main Results:

  • PR interval length inversely correlated with FMD (r = -0.30, P = 0.004) and positively with PWV (r = 0.40, P < 0.001).
  • Each 25 ms increase in PR interval was independently associated with reduced FMD and increased PWV.
  • These associations persisted after adjusting for confounders.

Conclusions:

  • PR interval length, even within the normal range, is independently associated with endothelial dysfunction and arterial stiffness.
  • Suggests an intermediate pathological vascular stage in PR prolongation.
  • This vascular dysfunction may mediate the increased cardiovascular risk observed with PR prolongation.