Fibrillatory Factor in Ventricular Tachycardia

The recruitment status of this study is unknown because the information has not been verified recently.
Verified October 2013 by Guy's and St Thomas' NHS Foundation Trust.
Recruitment status was  Not yet recruiting
Information provided by (Responsible Party):
Jaswinder Gill, M.D., Guy's and St Thomas' NHS Foundation Trust Identifier:
First received: July 13, 2013
Last updated: October 28, 2013
Last verified: October 2013

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.

Condition Intervention
Ventricular Tachycardia
Procedure: Fibrillatory Factor calculation (FF)

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Diagnostic
Official Title: Using Fibrillatory Factor to Predict the Source of Ventricular Tachycardia in Man

Resource links provided by NLM:

Further study details as provided by Guy's and St Thomas' NHS Foundation Trust:

Primary Outcome Measures:
  • Fibrillatory Factor [ Time Frame: 18 months ] [ Designated as safety issue: No ]
    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.

Secondary Outcome Measures:
  • Real-time fibrillatory factor [ Time Frame: 18 months ] [ Designated as safety issue: No ]
    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.

Estimated Enrollment: 20
Study Start Date: November 2013
Estimated Primary Completion Date: November 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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.


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01974908

Contact: Jaswinder Gill, MD +44 2071887188
Contact: Nicholas Child, BM +44 2071887188

United Kingdom
Guys and St Thomas' NHS Trust Not yet recruiting
London, United Kingdom, SE1 7EH
Principal Investigator: Jaswinder Gill, MD         
Sponsors and Collaborators
Guy's and St Thomas' NHS Foundation Trust
Principal Investigator: Jaswinder Gill, MD Guy's and St Thomas' NHS Trust
  More Information

Responsible Party: Jaswinder Gill, M.D., Consultant Electrophysiologist and Professor of Cardiology, Guy's and St Thomas' NHS Foundation Trust Identifier: NCT01974908     History of Changes
Other Study ID Numbers: GSTT-FF-1 
Study First Received: July 13, 2013
Last Updated: October 28, 2013
Health Authority: United Kingdom: Research Ethics Committee (London-Dulwich)
United Kingdom: Guy's and St Thomas' NHS Trust Research and Development

Keywords provided by Guy's and St Thomas' NHS Foundation Trust:
Ventricular Tachycardia

Additional relevant MeSH terms:
Tachycardia, Ventricular
Arrhythmias, Cardiac
Cardiovascular Diseases
Heart Diseases
Pathologic Processes processed this record on May 25, 2016