Related Experiment Video

Updated: Jan 1, 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

3.3K

Orthodromic atrioventricular reentrant tachycardia using a concealed isoproterenol-sensitive accessory pathway

Christian Steinberg1, François Philippon1, Gilles O'Hara1

  • 1Electrophysiology Division - Institut Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ), Laval University, Canada.

Indian Pacing and Electrophysiology Journal
|December 21, 2019
PubMed

Insights

This study reports a rare case of a concealed accessory pathway (AP) dependent on catecholamines, unmasked by isoproterenol. It emphasizes systematic isoproterenol use in electrophysiology studies to find such pathways and avoid missed ablation targets.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Cardiac Arrhythmias

Background:

  • Accessory pathways (APs) are the basis for atrioventricular reentrant tachycardia.
  • Catecholamine-sensitivity is a rare AP feature, typically seen with antegrade conduction.

Observation:

  • A concealed accessory pathway, unresponsive to baseline electrophysiology study, was identified.
  • This pathway exhibited catecholamine-dependency, requiring isoproterenol stimulation for unmasking.

Findings:

  • The concealed accessory pathway was successfully ablated after being revealed by isoproterenol.
  • The absence of retrograde ventriculo-atrial conduction did not rule out the concealed AP.

Implications:

  • Systematic isoproterenol stimulation is crucial in electrophysiology studies for supraventricular tachycardia.
  • This approach helps identify otherwise missed catecholamine-sensitive accessory pathways, preventing missed ablation targets.

Keywords:
Concealed accessory pathwayIsoproterenolOrthodromic atrioventricular reentrant tachycardia

More Related Videos

Viral Transgene Expression in Rodent Hearts and the Assessment of Cardiac Arrhythmia Risk05:15

Viral Transgene Expression in Rodent Hearts and the Assessment of Cardiac Arrhythmia Risk

Published on: July 27, 2022

2.0K
Dual-Dye Optical Mapping of Hearts from RyR2R2474S Knock-In Mice of Catecholaminergic Polymorphic Ventricular Tachycardia09:36

Dual-Dye Optical Mapping of Hearts from RyR2R2474S Knock-In Mice of Catecholaminergic Polymorphic Ventricular Tachycardia

Published on: December 22, 2023

1.6K

Related Concept Videos

Conduction System of the Heart01:19

Conduction System of the Heart

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...
12.3K
Conduction System of the Heart01:20

Conduction System of the Heart

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:...
3.2K
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...
2.4K
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.
1.5K
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...
8.6K
Dysrhythmias II: Classification of Tachyarrhythmias01:28

Dysrhythmias II: Classification of Tachyarrhythmias

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...
412