Fibrillatory Factor in Ventricular Tachycardia

Using Fibrillatory Factor to Predict the Source of Ventricular Tachycardia in Man

This study involves recording electrical signals inside the heart during an ablation procedure. It is thought that by studying these electrical signals in detail the investigators may be able to better identify and treat patients at risk of Ventricular Tachycardia (VT).

VT is where the lower chambers (ventricles) of your heart beat fast and this condition can be life-threatening. An ablation procedure is performed in patients who have VT despite the best treatment available with tablets.

Cardiac ablation involves interrupting the abnormal electrical signals, which cause VT, by applying a type of electrical energy through a catheter. An important part of the ablation procedure is the identification of the exact part of the heart muscle responsible for causing the VT. This typically involves sampling the electrical signals in lots of different areas of the heart, which allows the construction of computer generated 3 dimensional pictures of the structure and the electrical circuits inside the ventricle. Recent research has identified a new method to interpret these electrical signals (called Fibrillatory Factor - FF), which may allow better identification of the area within the ventricle that should be ablated.

A standard VT ablation will often involve us controlling the heart-beat by pacing the heart through 1 of the investigators catheters within the heart. The electrical response to pacing at different heart rates can often provide your doctor with information to help the ablation. This study will involve an additional period of pacing at different heart rates, during which the electrical response is measured in different areas around the ventricle. This will allow us to calculate areas of the ventricle, which the investigators new measure FF would predict to be the source of the VT. In the future this may then allow us to better identify patients who are at risk of VT, and to better locate the area that needs to be ablated.

Study Overview

• Status: Unknown
• Conditions: Ventricular Tachycardia
• Intervention / Treatment: Procedure: Fibrillatory Factor calculation (FF)

• Study Type: Interventional
• Enrollment (Anticipated): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • London, United Kingdom, SE1 7EH
    • Guys and St Thomas' NHS Trust

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Age 18 or above, and capable of giving informed consent
• Scheduled for a clinically indicated cardiac ablation for the treatment of ventricular tachycardia

Exclusion Criteria:

• Moderate or severe aortic stenosis or mitral stenosis
• Active infection
• Presence of thrombus, cardiac tumour, interatrial Baffle patch (a specific form of congenital cardiac surgery) or prior septal occluder device
• Subjects who cannot be anticoagulated of infused with heparinized saline
• A history of heparin induced thrombocytopenia
• Pregnant or actively breast feeding

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• 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: Ventricular Tachycardia (VT); Patients with VT will undergo a clinically indicated ablation of their VT	Procedure: Fibrillatory Factor calculation (FF); During sinus rhythm these patients will undergo a simple pacing protocol to allow us to calculate FF, which is an area we would predict is mod likely to be the origin of their VT.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fibrillatory Factor	To identify the proportion of clinical VT circuits which could be predicted during sinus rhythm from the calculation of fibrillation factor. The number of FF derived VT exit points which are successfully predicted blindly by the investigators (using the clinically derived VT exit point based on electrophysiology assessment and ablation) will be the primary endpoint.	18 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Real-time fibrillatory factor	Having established that fibrillatory factor (FF) can predict VT circuits we will then develop our software further so that we can calculate FF in real-time. This will then be used in further research studies to guide invasive mapping.	18 months

Collaborators and Investigators

• Sponsor: Guy's and St Thomas' NHS Foundation Trust
• Investigators: Principal Investigator: Jaswinder Gill, MD, Guy's and St Thomas' NHS Trust

Study record dates

Study Major Dates

• Study Start: November 1, 2013
• Primary Completion (Anticipated): November 1, 2014

Study Registration Dates

• First Submitted: July 13, 2013
• First Submitted That Met QC Criteria: October 28, 2013
• First Posted (Estimate): November 3, 2013

Study Record Updates

• Last Update Posted (Estimate): November 3, 2013
• Last Update Submitted That Met QC Criteria: October 28, 2013
• Last Verified: October 1, 2013

More Information

Terms related to this study

• Keywords: Ventricular Tachycardia
• Additional Relevant MeSH Terms: Pathologic Processes; Heart Diseases; Cardiovascular Diseases; Arrhythmias, Cardiac; Cardiac Conduction System Disease; Tachycardia; Tachycardia, Ventricular
• Other Study ID Numbers: GSTT-FF-1