Catheter Contact Force and Electrograms

This study is currently recruiting participants. (see Contacts and Locations)
Verified April 2014 by Barts & The London NHS Trust
Sponsor:
Information provided by (Responsible Party):
Barts & The London NHS Trust
ClinicalTrials.gov Identifier:
NCT01587404
First received: April 23, 2012
Last updated: April 1, 2014
Last verified: April 2014
  Purpose

Until recently, there was no way of telling how firmly the tip of the catheter was in contact with the heart and how this contact was orientated. The electrical signals measured through the catheters, known as electrograms, are used to guide the sites and duration of ablation, but the effect of catheter contact and orientation on these signals in human heart muscle that is fibrillating is not known. New catheters have now been developed which can measure the force of contact at their tip: using these, the investigators will examine how contact force affects the electrical behaviour of heart muscle tissue in atrial fibrillation. The effect the force of contact has on the electrogram recorded will also be investigated. In so doing we hope to gain a better understanding of the relationship between tissue contact and the electrograms we measure and in so doing improve the safety and effectiveness of ablation procedures.

Hypothesis: Catheter contact force and orientation have a significant impact on the characteristics of bipolar electrograms in the fibrillating human atrium.


Condition Intervention Phase
Atrial Fibrillation
Device: THERMOCOOL® SMARTTOUCH™ Catheter
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Diagnostic
Official Title: Relationship Between Catheter Contact Force and Electrogram Characteristics in Fibrillating Human Atrial Myocardium

Resource links provided by NLM:


Further study details as provided by Barts & The London NHS Trust:

Primary Outcome Measures:
  • Electrogram characteristics [ Time Frame: Baseline and 30 seconds ] [ Designated as safety issue: No ]
    Effect of changes in contact force and orientation on: slew rate, local mean cycle length, electrogram complexity and fractionation index, dominant frequency, organisation index, CFAE grade, interval confidence level, shortest complex interval and average complex interval


Secondary Outcome Measures:
  • Electrogram amplitude [ Time Frame: Baseline and 30 seconds ] [ Designated as safety issue: No ]
  • Electrogram responses to ablation [ Time Frame: Baseline and 30 seconds ] [ Designated as safety issue: No ]
    Slew rate, local mean cycle length, electrogram complexity and fractionation index, dominant frequency, organisation index, CFAE grade, interval confidence level, shortest complex interval and average complex interval, amplitude change, AF cycle length, catheter impedance.

  • Ablation Power (Watts) [ Time Frame: Baseline and 30 seconds ] [ Designated as safety issue: No ]
    The interaction between catheter contact force and orientation and the power attained during power limited ablation

  • Electrogram Contact Mapping [ Time Frame: During Study ] [ Designated as safety issue: No ]
    Use of contact catheters - Constellation and/or PentaRay Catheter to record fibrillatory electrograms and identify areas of interest


Estimated Enrollment: 40
Study Start Date: April 2012
Estimated Study Completion Date: April 2014
Estimated Primary Completion Date: April 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Constant Catheter Contact Force
No alteration of catheter contact force during recording period
Device: THERMOCOOL® SMARTTOUCH™ Catheter
Variable contact force as measured at the catheter tip within the left atrium
Experimental: Variable catheter contact force
change in contact force from low to high after 30seconds of recording.
Device: THERMOCOOL® SMARTTOUCH™ Catheter
Variable contact force as measured at the catheter tip within the left atrium

  Eligibility

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

Inclusion Criteria:

  • Persistent or paroxysmal atrial fibrillation
  • Listed for ablation of atrial fibrillation on clinical grounds

Exclusion Criteria:

  • Contraindication to catheter ablation
  • Contraindication to anticoagulation
  • Contraindication to TOE
  • Previous AF ablation
  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 ClinicalTrials.gov identifier: NCT01587404

Contacts
Contact: Richard J Schilling, MD +4420 3465 5398 Richard.Schilling@bartshealth.nhs.uk

Locations
United Kingdom
St Bartholomew's Hospital Recruiting
London, United Kingdom, EC1A 7BE
Principal Investigator: Richard J Schilling, MD         
Sponsors and Collaborators
Barts & The London NHS Trust
Investigators
Principal Investigator: Richard J Schilling, MD Professor of Cardiology and Electrophysiology St Barts Hospital and Queen Mary University
  More Information

No publications provided by Barts & The London NHS Trust

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Barts & The London NHS Trust
ClinicalTrials.gov Identifier: NCT01587404     History of Changes
Other Study ID Numbers: 007856 BLT
Study First Received: April 23, 2012
Last Updated: April 1, 2014
Health Authority: United Kingdom: Research Ethics Committee

Keywords provided by Barts & The London NHS Trust:
Atrial Fibrillation
Electrogram
Ablation
Contact Force

Additional relevant MeSH terms:
Atrial Fibrillation
Arrhythmias, Cardiac
Cardiovascular Diseases
Heart Diseases
Pathologic Processes

ClinicalTrials.gov processed this record on October 30, 2014