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Characterising the Stable and Dynamic Left Atrial Substrate in Atrial Fibrillation

NCT04229472 · Status: COMPLETED · Phase: NA · Type: INTERVENTIONAL · Enrollment: 31

Last updated 2025-08-19

Study results available
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Summary

Atrial fibrillation (AF) is the most common sustained arrhythmia, with increasing prevalence associated with an ageing population. Management is challenging, and invasive catheter ablation procedures are increasingly used in those with symptoms refractory to drug therapy. Unfortunately, success rates from this procedure can be limited. This is partly due to limitations in understanding of the mechanisms involved in arrhythmia propagation. There is much interest in the role of structural changes within the muscle of the left atrium resulting in scaring (known as fibrosis). This has been identified on MRI studies and invasive electroanatomical mapping using voltage amplitude of recorded signals as a surrogate measure of tissue properties. This however is affected by the technology used, as it does not routinely incorporate the effect of heart rate on conduction properties. Furthermore, although this aims to identify regions of structural changes, it does not identify more dynamic patterns of conduction seen during AF.

This study aims to use a high density mapping catheter (Abbott Advisa HD grid (SE)), which employs a novel algorithm to minimise the effect of wavefront direction on the size of electrical signals. Electroanatomical mapping of the left atrium in patients with atrial fibrillation will be conducted whilst pacing at long and short cycle lengths to assess the effect of pacing rate on conduction properties, assessed using signal morphology and conduction velocity. The same procedure will also be carried out in 5 control patients to allow comparison with normal atria. Two subgroups will also analysed. In the first the aim is to compare the use of the HD grid catheter to a bipolar ablation catheter in carrying out electroanatomical mapping. In the second, to correlate electrical signals obtained with propagation patterns identified using the AcQMap non-contact mapping system and atrial properties identified on cardiac MRI.

Conditions

Interventions

DIAGNOSTIC_TEST

High density electrophysiological mapping

Recording of electrophysiological data using a high density contact catheter during pacing at the time of catheter ablation for atrial fibrillation.

DIAGNOSTIC_TEST

Cardiac Magnetic Resonance Imaging

Late gadolinium enhance cardiac magnetic resonance imaging (in AcQMap group only)

Sponsors & Collaborators

  • Oxford University Hospitals NHS Trust

    lead OTHER

Principal Investigators

  • Timothy R Betts, MD MBChB FRCP · Oxford University Hospitals NHS Trust

Study Design

Allocation
NON_RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
NONE
Model
PARALLEL

Eligibility

Min Age
18 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2020-12-07
Primary Completion
2023-11-02
Completion
2023-11-02

Countries

  • United Kingdom

Study Locations

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Entities

Diseases

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT04229472 on ClinicalTrials.gov