Atrial FibrillationCASDAF-HDNCT04229472
Characterising the Stable and Dynamic Left Atrial Substrate in Atrial Fibrillation
A study testing High density electrophysiological mapping and Cardiac Magnetic Resonance Imaging in people with Atrial Fibrillation, run by Oxford University Hospitals NHS Trust at 1 site in United Kingdom.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Atrial Fibrillation
- What is being tested?
- High density electrophysiological mapping and Cardiac Magnetic Resonance Imaging
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 31 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 7 Dec 2020to 2 Nov 2023
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Participant is willing and able to give informed consent for participation in the study.
- Male or Female, aged 18 years or above.
- Diagnosed with paroxysmal or persistent atrial fibrillation and planned for a catheter ablation procedure (AF ablation group only).
- Undergoing elective left sided catheter ablation procedure involving a trans-septal approach (Control group only).
- In the Investigator's opinion the participant is able and willing to comply with all trial requirements.
Who cannot join
- Previous cardiac surgery.
- Previous left atrial ablation (catheter or surgical).
- Medical history including any of: atrial fibrillation, atrial flutter, hypertension, diabetes mellitus, chronic obstructive pulmonary disease, significant mitral valve disease (stenosis or regurgitation), pulmonary hypertension, obstructive sleep apnoea, ischaemic heart disease, cerebrovascular disease, peripheral vascular disease, structural heart disease (excluding known accessory pathway), congenital cardiac anomaly (excluding accessory pathway), previous left atrial ablation (catheter or surgical), cardiac surgery (control group only).
- Contraindications to MR scanning (such as metallic or electronic objects implanted in your body or history of severe claustrophobia) (AcQMap guided ablation group).
- Significantly impaired renal function (eGFR<30ml/min).
- Female participant who is pregnant, lactating or planning pregnancy during the course of the trial.
- Any other significant disease or disorder which, in the opinion of the Investigator, may either put the participants at risk because of participation in the trial, or may influence the result of the trial, or the participant's ability to participate in the trial.
- Participants who have participated in another research trial involving an investigational medicinal product in the past 12 weeks. (Involvement in any other research trial is not a contraindication per se).
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
John Radcliffe Hospital
Oxford, Oxfordshire, OX3 9DU
About this study
Official title: Characterising the Stable and Dynamic Left Atrial Substrate in Atrial Fibrillation Using High Density Contact and Non-contact Mapping
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.
Read the detailed description
This is a prospective, non-randomised mechanistic study of 35 patients, including 5 control patients with normal atria and 30 patients with atrial fibrillation.
The 5 control patients will be undergoing an elective catheter ablation for another arrhythmia (likely supraventricular tachycardia (SVT)) involving a trans-septal puncture for left atrial access.
The 30 main study participants will only be patients who are already planning to undergo a catheter ablation procedure for atrial fibrillation. This will include 10 patients who are undergoing elective AcQMap guided procedures, in order to correlate non-contact propagation patterns with contact substrate mapping. These 10 patients will also undergo cardiac MRI imaging.
Study participants will be identified by medical staff in the outpatient clinic at the time of listing for catheter ablation, or by review of patients electronically listed for this procedure. If patients are in the clinic and give consent then a member of the research team may approach them at this stage. If identified by medical staff through listing for the procedure, they will be approached by telephone. An information leaflet will then be provided by post or email (if this has not been provided in clinic) with contact details for the research team. If willing to participate then formal screening and recruitment will take place at the time of attendance for standard pre-procedure assessment appointments or when attending for the elective procedure. Information must have been provided with sufficient time for the potential participant to fully consider involvement prior to formal recruitment and consent (generally expected to be at least 24 hours). It will be clear that participation or choosing not to participate has no impact on proceeding with their planned procedure. As the baseline assessments required involve purely a review of a participants medical history and measurement of height and weight, this will be combined with the screening/recruitment visit, and providing information has been provided sufficiently in advance then may be undertaken at the time of attending for the study procedure.
Study procedure:
In line with standard practice in this institution, all AF ablation procedures will be undertaken under general anaesthesia. SVT ablation will be conducted under sedation. Venous access, trans-septal puncture and placement of standard electrophysiology catheters will be undertaken in accordance with standard clinical care. Anticoagulation will be administered following trans-septal puncture in line with standard protocols.
All participants:
All study participants will undergo electroanatomical voltage mapping (EAVM) using the Abbott Advisa HD Grid (SE) mapping catheter using the orthogonal wave setting (HD wave solution). If in AF at the start of the procedure then direct current cardioversion (DCCV) will be used to restore sinus rhythm. This can be repeated at the discretion of the operator if initially unsuccessful (including internal cardioversion if necessary). If unsuccessful then the patient will no longer be included in the study. Mapping will then be undertaken during bipolar pacing from the mid point of the coronary sinus catheter whilst pacing at 800ms for 4 beats followed by a single beat at 300ms (or the shortest captured if longer). Ablation and the rest of the procedure can then be performed according to standard clinical practice.
For the 30 patients undergoing AF ablation, once the initial study procedures above are complete, further mapping will be conducted using either an ablation catheter (20 patients) or the AcQMap system (10 patients).
Ablation catheter mapping:
This involves using a contact force guided bipolar irrigated ablation catheter (Abbott Tacticath) during the same pacing protocol. For patients presenting in sinus rhythm or AF, all required mapping should be completed in the presenting rhythm followed by either AF induction (using incremental burst atrial pacing) or DCCV respectively before completion of mapping procedures. Ablation in line with standard clinical care will be undertaken following completion of all mapping procedures.
AcQMap guided mapping and ablation:
10 patients with persistent AF who are undergoing AcQMap guided elective catheter ablation procedures will be included. All patients will undergo the same main study mapping procedure outlined above. In addition, AcQMap recordings will also be obtained. Recordings will be made during pacing with the same main study protocol and two 30second recordings will be undertaken during AF. HD grid contact recordings will then also be obtained in regions of prominent rotational and irregular conduction identified by AcQMap and ablation performed at the operator's discretion.
Post procedure care including subsequent discharge will continue in line with standard clinical practice and no study follow up is required (excluding the repeat MRI referred to below).
Cardiac MRI:
The 10 participants undergoing elective AcQMap guided procedures will also undergo a cardiac MRI both prior to and after the procedure. The initial scan will be within the 6 weeks prior to the ablation procedure and the follow up scan will be within 3-6 months after the procedure. These will be planned whenever possible to take place alongside routine hospital visits.
Patients will complete an MRI safety questionnaire (5 minutes) prior to the scan. An intravenous cannula will be inserted. Cardiac MRI will evaluate cardiac structure and function, with particular focus on the left atrium. For late gadolinium enhancement imaging, the total dose of gadolinium-based contrast will not exceed 0.2mmol/kg.
The total duration of the MR protocol will be approximately 60 minutes, considering approximately 50 minutes of scanning time, plus approximately 10 minutes for pre/post-scan preparation.
It is planned that a total of 35 patients will be recruited to this study. As this study is not evaluating clinical outcomes of a procedure, greater numbers are not needed. This number is thought to be enough to reveal any patterns in electrophysiological properties. Data analysis will occur offline using anonymised datasets. Results will be collated and a report compiled at the end of the study.
- Conditions
- Atrial Fibrillation
- Being tested
- High density electrophysiological mapping, Cardiac Magnetic Resonance Imaging
- Medical subject headings
- Atrial Fibrillation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
High density electrophysiological mappingDiagnostic test
Recording of electrophysiological data using a high density contact catheter during pacing at the time of catheter ablation for atrial fibrillation.
Cardiac Magnetic Resonance ImagingDiagnostic test
Late gadolinium enhance cardiac magnetic resonance imaging (in AcQMap group only)
| Study group | Role | What they receive |
|---|---|---|
| Normal subject control group | Experimental | High density mapping of left atrial voltages in patients with supraventricular tachycardia Receives: Diagnostic Test: High density electrophysiological mapping |
| Atrial fibrillation group | Experimental | High density mapping of left atrial voltages Receives: Diagnostic Test: High density electrophysiological mapping |
| AcQMap atrial fibrillation group | Experimental | High density mapping of left atrial voltages and AcQMap propagation patterns alongside cardiac MRI Receives: Diagnostic Test: High density electrophysiological mapping; Diagnostic Test: Cardiac Magnetic Resonance Imaging |
What is being measured
The primary outcome is the main question the study is designed to answer.
To Define the Normal Range of Voltage Amplitude
Mean and distribution of left atrial voltage amplitude across the whole chamber and by segments with lower limit of normal defined as the upper 95% value within the segment with the lowest mean amplitude at long pacing cycle length.
Measured: During ablation procedure
Secondary outcomes (6)
Effect of Pacing Cycle Length on Electrogram Morphology
A change in electrogram morphology from normal to abnormal (defined as ≥3 deflections lasting ≥50ms) between long and short pacing cycle length in regions of low (<0.5mV), intermediate (0.5-lower limit of normal defined from control group) and normal (defined from control group results) voltage amplitude.
Measured: During ablation procedure
Effect of Pacing Cycle Length on Conduction Velocity
Difference in single vector conduction velocity at long and short cycle lengths in regions of low, intermediate and normal voltage.
Measured: During ablation procedure
To Compare Electroanatomic Voltage Mapping (EAVM) Performed With a Bipolar Contact Force Guided Ablation Catheter to the Abbott HD Grid Using Orthogonal Wave Analysis in Sinus Rhythm.
Difference in voltage amplitude by each method in sinus rhythm.
Measured: During ablation procedure
To Evaluate the Distribution of Late Gadolinium Enhancement on Cardiac MRI Relative to Electrogram Amplitude Identified Using the HD Grid
Difference in electrogram voltage amplitude at long and short cycle length in regions with and without late gadolinium enhancement on cardiac MRI.
Measured: During ablation procedure
To Evaluate the Distribution of Electrogram Morphologies Relative to Late Gadolinium Enhancement on Cardiac MRI
Difference in proportion of abnormal electrograms >50ms duration and >3 deflections at long and short cycle length in regions with and without late gadolinium enhancement on cardiac MRI.
Measured: During ablation procedure
To Evaluate the Effect of Cycle Length on Conduction Velocities Relative to Distribution of Late Gadolinium Enhancement on Cardiac MRI
Difference in conduction velocities at long and short cycle length in regions with and without late gadolinium enhancement on cardiac MRI.
Measured: During ablation procedure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Jan 2020
- Study start7 Dec 2020
- Primary completion2 Nov 2023
- Study completion2 Nov 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Atrial FibrillationStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 31 participants (actual)
Sponsor and investigators
- Lead sponsor
- Oxford University Hospitals NHS Trust
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Tim Betts MD MBChB FRCP, Oxford University Hospitals NHS Trust
- Investigators
- Timothy R Betts, MD MBChB FRCP, Principal investigator, Oxford University Hospitals NHS Trust
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04229472
- Sponsor's protocol ID
- 14295
- Acronym
- CASDAF-HD
- Status last verified
- Jul 2025
- First submitted
- 7 Jan 2020
- Last updated
- 19 Aug 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 19 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Characterising the Stable and Dynamic Left Atrial Substrate in Atrial Fibrillation Using High Density Contact and Non-contact Mapping
- ClinicalTrials.gov ID
- NCT04229472
- Acronym / sponsor ID
- CASDAF-HD / 14295
- Conditions
- Atrial Fibrillation
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 31 participants (actual)
- Lead sponsor
- Oxford University Hospitals NHS TrustUniversity, hospital or other
- Study start
- 7 Dec 2020 (actual)
- Primary completion
- 2 Nov 2023 (actual)
- Study completion
- 2 Nov 2023 (actual)
- First posted
- 18 Jan 2020 (actual)
- Results
- Posted 19 Aug 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
This is a prospective, non-randomised mechanistic study of 35 patients, including 5 control patients with normal atria and 30 patients with atrial fibrillation.
The 5 control patients will be undergoing an elective catheter ablation for another arrhythmia (likely supraventricular tachycardia (SVT)) involving a trans-septal puncture for left atrial access.
The 30 main study participants will only be patients who are already planning to undergo a catheter ablation procedure for atrial fibrillation. This will include 10 patients who are undergoing elective AcQMap guided procedures, in order to correlate non-contact propagation patterns with contact substrate mapping. These 10 patients will also undergo cardiac MRI imaging.
Study participants will be identified by medical staff in the outpatient clinic at the time of listing for catheter ablation, or by review of patients electronically listed for this procedure. If patients are in the clinic and give consent then a member of the research team may approach them at this stage. If identified by medical staff through listing for the procedure, they will be approached by telephone. An information leaflet will then be provided by post or email (if this has not been provided in clinic) with contact details for the research team. If willing to participate then formal screening and recruitment will take place at the time of attendance for standard pre-procedure assessment appointments or when attending for the elective procedure. Information must have been provided with sufficient time for the potential participant to fully consider involvement prior to formal recruitment and consent (generally expected to be at least 24 hours). It will be clear that participation or choosing not to participate has no impact on proceeding with their planned procedure. As the baseline assessments required involve purely a review of a participants medical history and measurement of height and weight, this will be combined with the screening/recruitment visit, and providing information has been provided sufficiently in advance then may be undertaken at the time of attending for the study procedure.
Study procedure:
In line with standard practice in this institution, all AF ablation procedures will be undertaken under general anaesthesia. SVT ablation will be conducted under sedation. Venous access, trans-septal puncture and placement of standard electrophysiology catheters will be undertaken in accordance with standard clinical care. Anticoagulation will be administered following trans-septal puncture in line with standard protocols.
All participants:
All study participants will undergo electroanatomical voltage mapping (EAVM) using the Abbott Advisa HD Grid (SE) mapping catheter using the orthogonal wave setting (HD wave solution). If in AF at the start of the procedure then direct current cardioversion (DCCV) will be used to restore sinus rhythm. This can be repeated at the discretion of the operator if initially unsuccessful (including internal cardioversion if necessary). If unsuccessful then the patient will no longer be included in the study. Mapping will then be undertaken during bipolar pacing from the mid point of the coronary sinus catheter whilst pacing at 800ms for 4 beats followed by a single beat at 300ms (or the shortest captured if longer). Ablation and the rest of the procedure can then be performed according to standard clinical practice.
For the 30 patients undergoing AF ablation, once the initial study procedures above are complete, further mapping will be conducted using either an ablation catheter (20 patients) or the AcQMap system (10 patients).
Ablation catheter mapping:
This involves using a contact force guided bipolar irrigated ablation catheter (Abbott Tacticath) during the same pacing protocol. For patients presenting in sinus rhythm or AF, all required mapping should be completed in the presenting rhythm followed by either AF induction (using incremental burst atrial pacing) or DCCV respectively before completion of mapping procedures. Ablation in line with standard clinical care will be undertaken following completion of all mapping procedures.
AcQMap guided mapping and ablation:
10 patients with persistent AF who are undergoing AcQMap guided elective catheter ablation procedures will be included. All patients will undergo the same main study mapping procedure outlined above. In addition, AcQMap recordings will also be obtained. Recordings will be made during pacing with the same main study protocol and two 30second recordings will be undertaken during AF. HD grid contact recordings will then also be obtained in regions of prominent rotational and irregular conduction identified by AcQMap and ablation performed at the operator's discretion.
Post procedure care including subsequent discharge will continue in line with standard clinical practice and no study follow up is required (excluding the repeat MRI referred to below).
Cardiac MRI:
The 10 participants undergoing elective AcQMap guided procedures will also undergo a cardiac MRI both prior to and after the procedure. The initial scan will be within the 6 weeks prior to the ablation procedure and the follow up scan will be within 3-6 months after the procedure. These will be planned whenever possible to take place alongside routine hospital visits.
Patients will complete an MRI safety questionnaire (5 minutes) prior to the scan. An intravenous cannula will be inserted. Cardiac MRI will evaluate cardiac structure and function, with particular focus on the left atrium. For late gadolinium enhancement imaging, the total dose of gadolinium-based contrast will not exceed 0.2mmol/kg.
The total duration of the MR protocol will be approximately 60 minutes, considering approximately 50 minutes of scanning time, plus approximately 10 minutes for pre/post-scan preparation.
It is planned that a total of 35 patients will be recruited to this study. As this study is not evaluating clinical outcomes of a procedure, greater numbers are not needed. This number is thought to be enough to reveal any patterns in electrophysiological properties. Data analysis will occur offline using anonymised datasets. Results will be collated and a report compiled at the end of the study.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Normal subject control group | Experimental | Diagnostic Test: High density electrophysiological mappingHigh density mapping of left atrial voltages in patients with supraventricular tachycardia |
| Atrial fibrillation group | Experimental | Diagnostic Test: High density electrophysiological mappingHigh density mapping of left atrial voltages |
| AcQMap atrial fibrillation group | Experimental | Diagnostic Test: High density electrophysiological mapping, Diagnostic Test: Cardiac Magnetic Resonance ImagingHigh density mapping of left atrial voltages and AcQMap propagation patterns alongside cardiac MRI |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Participant is willing and able to give informed consent for participation in the study.
- Male or Female, aged 18 years or above.
- Diagnosed with paroxysmal or persistent atrial fibrillation and planned for a catheter ablation procedure (AF ablation group only).
- Undergoing elective left sided catheter ablation procedure involving a trans-septal approach (Control group only).
- In the Investigator's opinion the participant is able and willing to comply with all trial requirements.
Key exclusion criteria (8 listed)
- Previous cardiac surgery.
- Previous left atrial ablation (catheter or surgical).
- Medical history including any of: atrial fibrillation, atrial flutter, hypertension, diabetes mellitus, chronic obstructive pulmonary disease, significant mitral valve disease (stenosis or regurgitation), pulmonary hypertension, obstructive sleep apnoea, ischaemic heart disease, cerebrovascular disease, peripheral vascular disease, structural heart disease (excluding known accessory pathway), congenital cardiac anomaly (excluding accessory pathway), previous left atrial ablation (catheter or surgical), cardiac surgery (control group only).
- Contraindications to MR scanning (such as metallic or electronic objects implanted in your body or history of severe claustrophobia) (AcQMap guided ablation group).
- Significantly impaired renal function (eGFR<30ml/min).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| High density electrophysiological mappingRecording of electrophysiological data using a high density contact catheter during pacing at the time of catheter ablation for atrial fibrillation. | Diagnostic test | AcQMap atrial fibrillation group, Atrial fibrillation group, Normal subject control group |
| Cardiac Magnetic Resonance ImagingLate gadolinium enhance cardiac magnetic resonance imaging (in AcQMap group only) | Diagnostic test | AcQMap atrial fibrillation group |
Primary outcome
To Define the Normal Range of Voltage Amplitude
Time frame: During ablation procedure
Mean and distribution of left atrial voltage amplitude across the whole chamber and by segments with lower limit of normal defined as the upper 95% value within the segment with the lowest mean amplitude at long pacing cycle length.
6 secondary outcomes
Effect of Pacing Cycle Length on Electrogram Morphology
Time frame: During ablation procedure
Effect of Pacing Cycle Length on Conduction Velocity
Time frame: During ablation procedure
To Compare Electroanatomic Voltage Mapping (EAVM) Performed With a Bipolar Contact Force Guided Ablation Catheter to the Abbott HD Grid Using Orthogonal Wave Analysis in Sinus Rhythm.
Time frame: During ablation procedure
To Evaluate the Distribution of Late Gadolinium Enhancement on Cardiac MRI Relative to Electrogram Amplitude Identified Using the HD Grid
Time frame: During ablation procedure
To Evaluate the Distribution of Electrogram Morphologies Relative to Late Gadolinium Enhancement on Cardiac MRI
Time frame: During ablation procedure
To Evaluate the Effect of Cycle Length on Conduction Velocities Relative to Distribution of Late Gadolinium Enhancement on Cardiac MRI
Time frame: During ablation procedure
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Aug 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Timothy R Betts, MD MBChB FRCP principal investigator
Oxford University Hospitals NHS Trust
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing High density electrophysiological mapping and Cardiac Magnetic Resonance Imaging in people with Atrial Fibrillation, run by Oxford University Hospitals NHS Trust at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 19 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 19 Aug 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To Define the Normal Range of Voltage Amplitude (time frame: During ablation procedure). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Aug 2025.