Related Experiment Video

Updated: Apr 4, 2026

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

3.7K

High atrioventricular phase index on near-field intracardiac electrogram is associated with risk of ventricular

Muammar M Kabir1, Elyar Ghafoori1, Larisa G Tereshchenko1

  • 1Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA.

Journal of Electrocardiology
|September 5, 2015
PubMed

Insights

In implantable cardioverter-defibrillator (ICD) patients, high atrial-ventricular (AV) phase dependency predicts a greater risk of ventricular arrhythmias. This finding aids in assessing arrhythmia risk in patients with structural heart disease.

Area of Science:

  • Cardiology
  • Biomedical Engineering
  • Electrophysiology

Background:

  • Atrial and ventricular activation timing is crucial for cardiac function.
  • Understanding the relationship between atrial and ventricular activation can improve risk stratification in patients with implantable cardioverter-defibrators (ICDs).

Purpose of the Study:

  • To characterize and quantify the concordance between consecutive atrial and ventricular activation time points using phase analysis.
  • To explore the association between this concordance and clinical outcomes in patients with ICDs.

Main Methods:

  • Patients with structural heart disease and dual-chamber ICDs underwent baseline electrogram (EGM) recordings.
  • Cross-dependencies of phase dynamics for consecutive atrial (AA') and ventricular (VV') activations were quantified.
  • The atrial-ventricular (AV) phase dependency index was determined.

Main Results:

  • A high AV phase dependency index (highest quartile, >0.259) was significantly associated with an increased risk of ventricular tachyarrhythmias.
  • Cox regression analysis indicated a hazard ratio of 2.84 (95% CI 1.05-7.67; P=0.04) for higher risk.

Conclusions:

  • In ICD patients with structural heart disease, a high sinus AV phase dependency index derived from EGMs is linked to an elevated risk of ventricular arrhythmias.
  • This index may serve as a valuable tool for predicting arrhythmia risk.

Keywords:
AtrialPhase dependencySymbolic dynamicsSympatheticVentricular

More Related Videos

High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation09:17

High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation

Published on: July 29, 2011

15.3K
Electrophysiological Assessment of Murine Atria with High-Resolution Optical Mapping08:19

Electrophysiological Assessment of Murine Atria with High-Resolution Optical Mapping

Published on: February 22, 2018

10.7K

Related Concept Videos

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...
994
Electrophysiology of Normal Cardiac Rhythm01:19

Electrophysiology of Normal Cardiac Rhythm

The normal cardiac rhythm is a synchronized electrical activity that facilitates the regular and coordinated contraction of the heart muscle. This process is essential for efficient blood circulation throughout the body. The fundamental elements involved in establishing and maintaining this rhythm include the unique electrical properties of cardiac muscle cells, the sinoatrial (SA) node's pacemaker function, the specialized conducting system, and the ionic mechanisms underlying each phase...
10.4K
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...
812
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...
3.9K
Cardiac Action Potential01:30

Cardiac Action Potential

Cardiac action potentials are essential for proper heart function, enabling the rhythmic contractions needed for adequate blood circulation. Nodal cells and Purkinje fibers, specialized for electrical conduction, generate these action potentials.
The cardiac action potential process involves a series of phases characterized by the movement of ions across the cardiac cell membranes, leading to the depolarization and repolarization of the cardiac myocytes.
Ionic Basis of Cardiac Action Potentials
9.3K
Mechanism of Cardiac Arrhythmias01:28

Mechanism of Cardiac Arrhythmias

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.
2.7K