Ventricular Tachycardia Mechanisms

Ventricular Tachycardia Substrate Mechanisms Revealed by Local Repolarization and Conduction Parameters

The purpose of this study is to understand why certain hearts have ventricular arrhythmias and help identify areas of the heart that cause arrhythmias. There is still a significant gap in understanding why ventricular arrhythmias occur. This study will examine the electrical properties of the heart tissue to understand how these arrhythmias occur, and hopefully identify areas that might lead to ventricular arrhythmias. The hope is that studying this might be able to improve outcomes during ventricular tachycardia (VT) ablations.

Study Overview

• Status: Recruiting
• Conditions: Ventricular Tachycardia
• Intervention / Treatment: Device: Monophasic Action Potential (MAP) Catheter

Detailed Description

Ventricular tachycardia (VT) ablation remains the cornerstone treatment for drug refractory VT. Previous studies have reported success rate of VT ablation ranging from 23 to 49%. Despite improvements in mapping and catheter technology, there is a high recurrence rate and numerous patients who fail VT ablation.

Reasons for failure in VT ablation include the inability to identify critical areas of myocardium responsible for VT and hemodynamic instability of VT during mapping. Several studies have attempted to study electrical properties of cardiac tissues to identify potential circuits in sinus rhythm avoid mapping during unstable VT. This includes mapping fractionated electrical potentials, isochronal late activation mapping (ILAM), and ablation of low voltage regions. However, these techniques have yielded modest improvement in success rates with poor specificity of identifying important regions.

Monophasic action potentials (MAP) demonstrate cellular action potential of the myocardium. Recent evidence suggests that changes in MAP morphology can predict sudden cardiac death by ventricular arrhythmias. However, cellular activation has not been studied in VT. The researchers of this study propose that MAP signals can better elucidate electrophysiological characteristics of the myocardium, and thus identify sites critical to VT.

During a standard of care VT ablation, the researchers will use the MAP catheter to study cellular action potential of the ventricular myocardium, which cannot be done on traditional catheters. The design of this catheter is similar to other diagnostic catheters that are currently used for VT ablation. The MAP catheter is a bipolar catheter, two with electrical poles at the distal tip. The catheter is placed on the myocardium (similar to other traditional catheters) and a recording signal is transmitted to the workstation. Using the MAP catheter the will not interrupt or distort any of the standard treatment procedures.

• Study Type: Interventional
• Enrollment (Estimated): 10
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Neal Bhatia, MD; Phone Number: 404-686-7878; Email: neal.kumar.bhatia@emory.edu

Study Locations

• United States
  • Georgia
    • Atlanta, Georgia, United States, 30308
      • Recruiting
      • Emory University Hospital Midtown
    • Atlanta, Georgia, United States, 30322
      • Recruiting
      • Emory Clinic
    • Atlanta, Georgia, United States, 30322
      • Recruiting
      • Emory University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Diagnosis of ischemic cardiomyopathy
• Single or dual chamber implantable cardioverter-defibrillator (ICD)

Exclusion Criteria:

• Non-Ischemic cardiomyopathy
• Contraindication to catheter ablation
• Severe peripheral arterial disease or medical condition that prohibit arterial access
• Ventricular tachycardia (VT) or sudden cardiac arrest (SCA) within 30 days of acute coronary syndrome or within 90 days of coronary revascularization

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Monophasic Action Potential (MAP) Catheter; Participants undergoing ventricular tachycardia ablation per standard of care will also have cellular action potential of the ventricular myocardium assessed with the MAP catheter.

Device: Monophasic Action Potential (MAP) Catheter; The EasyMap catheter is a temporary quadripolar catheter for recording monophasic action potentials and for intracardiac pacing. During a standard of care VT ablation, the MAP catheter will be used to study cellular action potential of the ventricular myocardium, which cannot be done on traditional catheters. The catheter is placed on the myocardium (similar to other traditional catheters) and a recording signal is transmitted to the workstation. Using the MAP catheter the will not interrupt or distort any of the standard treatment procedures.; Other Names: EasyMap catheter

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Waveform Morphology	Identification of sites that are critical to reentry of ventricular tachycardia from bystander sites will be performed by analyzing local ventricular activation. Local ventricular action is assessed with waveform morphology and is measured in voltage (mV). The normal range is >3 mV bipolar and >8.3 mV unipolar.	During ablation on Day 1
Conduction Velocity	Identification of sites that are critical to reentry of ventricular tachycardia from bystander sites will be performed by analyzing electrophysiological properties. Electrophysiological properties are assessed with conduction velocity, measured in meters per second (m/s).	During ablation on Day 1

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Identify mechanisms of slowed conduction at ILAM	The mechanisms responsible for slowed conduction at sites that are critical to ventricular tachycardia using monophasic action potential signals will be examined.	During ablation on Day 1
Identify surrogate markers	Surrogate markers for monophasic action potential tracings will be compared to conventional mapping catheters.	During ablation on Day 1

Collaborators and Investigators

• Sponsor: Emory University
• Investigators: Principal Investigator: Neal Bhatia, MD, Emory University

Study record dates

Study Major Dates

• Study Start (Actual): October 25, 2022
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): May 1, 2026

Study Registration Dates

• First Submitted: June 28, 2022
• First Submitted That Met QC Criteria: July 26, 2022
• First Posted (Actual): July 28, 2022

Study Record Updates

• Last Update Posted (Actual): January 15, 2026
• Last Update Submitted That Met QC Criteria: January 14, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Ventricular tachycardia ablation
• Additional Relevant MeSH Terms: Cardiac Conduction System Disease; Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Tachycardia; Pathological Conditions, Signs and Symptoms; Tachycardia, Ventricular; Equipment and Supplies; Catheters
• Other Study ID Numbers: STUDY00003571; 2024P008207 (Other Identifier: Emory IRB)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No