Catheter Contact Force and Electrograms

Phase 4

Completed

• Conditions: Atrial Fibrillation
• Interventions: Device: THERMOCOOL® SMARTTOUCH™ Catheter (including Surround Flow)

• Registration Number: NCT01587404
• Lead Sponsor: Barts & The London NHS Trust

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2012-04
• Study First Submitted: 2012-04-23
• Study First Submitted QC: 2012-04-26
• Study First Posted: 2012-04-30
• Primary Completion: 2017-05-31
• Study Completion: 2018-08-21
• Status Verified: 2019-09
• Last Update Submitted: 2019-09-26
• Last Update Posted: 2019-09-30

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 55

Inclusion Criteria

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

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Exclusion Criteria

• Contraindication to catheter ablation
• Contraindication to anticoagulation
• Contraindication to TOE

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Constant Catheter Contact Force	THERMOCOOL® SMARTTOUCH™ Catheter (including Surround Flow)	No alteration of catheter contact force during recording period
Variable catheter contact force	THERMOCOOL® SMARTTOUCH™ Catheter (including Surround Flow)	change in contact force from low to high after 30seconds of recording.

Primary Outcome Measures

Name	Time	Method
Electrogram characteristics	Baseline and 30 seconds	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

Name	Time	Method
Electrogram Contact Mapping	During Study	Use of contact catheters - Constellation and/or PentaRay Catheter to record fibrillatory electrograms and identify areas of interest
Ablation Power (Watts)	Baseline and 30 seconds	The interaction between catheter contact force and orientation and the power attained during power limited ablation
Electrogram amplitude	Baseline and 30 seconds
Electrogram responses to ablation	Baseline and 30 seconds	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.

Trial Locations

Locations (1)

St Bartholomew's Hospital; 🇬🇧 London, United Kingdom