Related Experiment Video

Updated: Oct 3, 2026

Dual-Dye Optical Mapping of Hearts from RyR2R2474S Knock-In Mice of Catecholaminergic Polymorphic Ventricular Tachycardia
09:36

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

Published on: December 22, 2023

Verapamil-sensitive left ventricular tachycardia in patients with coronary artery disease: clinical and

C Sorbera1, M Cohen, V Kuznetsov

  • 1Division of Cardiology, Westchester Medical Center, New York Medical College, Valhalla, New York 10595, USA.

Heart Disease (Hagerstown, Md.)
|November 27, 2001
PubMed

Insights

Verapamil effectively treated left ventricular tachycardia in patients with severe coronary artery disease. This suggests triggered activity in the Purkinje system, responsive to calcium channel blockers, is a key mechanism.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Pharmacology

Background:

  • Patients with severe coronary artery disease and myocardial infarction often present with complex ventricular arrhythmias.
  • Left ventricular tachycardia (LVT) in this population can be challenging to manage, impacting cardiac function and prognosis.

Observation:

  • Three male patients with severe coronary artery disease, prior myocardial infarction, and significant left ventricular dysfunction (mean EF 34%) experienced verapamil-sensitive LVT.
  • The LVT exhibited a right bundle branch block/left axis deviation morphology and was sustained by isoproterenol.
  • One patient had incessant LVT post-coronary bypass surgery.

Findings:

  • Electrophysiological studies suggested triggered activity, potentially in the Purkinje system, as the mechanism, differing from typical reentry mechanisms seen in non-ischemic VT.
  • Verapamil successfully terminated the LVT in all patients.
  • Adenosine, beta-blockers, and Class I/III antiarrhythmics were ineffective.
  • Radiofrequency ablation guided by Purkinje potentials was successful.

Implications:

  • Verapamil-sensitive LVT in ischemic heart disease may arise from triggered activity, responsive to calcium channel blockade.
  • This finding expands the understanding of VT mechanisms in patients with structural heart disease.
  • Targeting Purkinje system activity with calcium channel blockers or ablation offers a potential therapeutic strategy.

More Related Videos

Ablation of Ischemic Ventricular Tachycardia Using a Multipolar Catheter and 3-dimensional Mapping System for High-density Electro-anatomical Reconstruction06:57

Ablation of Ischemic Ventricular Tachycardia Using a Multipolar Catheter and 3-dimensional Mapping System for High-density Electro-anatomical Reconstruction

Published on: January 31, 2019

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...
Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers01:20

Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers

Class IV antiarrhythmic drugs, such as verapamil and diltiazem, block calcium channels. They primarily affect the heart, slowing the conduction in calcium-dependent tissues like the SA and AV nodes. These drugs manage reentrant supraventricular tachycardia (SVT) and reduce ventricular rate in atrial flutter/fibrillation.
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
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.
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.
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...
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...