Atrial Fibrillation
Conditions
Keywords
Atrial Fibrillation, Electrogram, Ablation, Contact Force
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.
Interventions
DEVICETHERMOCOOL® SMARTTOUCH™ Catheter (including Surround Flow)
Variable contact force as measured at the catheter tip within the left atrium
Sponsors
Barts & The London NHS Trust
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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. |
| Ablation Power (Watts) | Baseline and 30 seconds | The interaction between catheter contact force and orientation and the power attained during power limited ablation |
| Electrogram Contact Mapping | During Study | Use of contact catheters - Constellation and/or PentaRay Catheter to record fibrillatory electrograms and identify areas of interest |
Countries
United Kingdom
Outcome results
None listed