High-resolution MRI of Atrial Fibrillation Patients Prior to Focal Impulse and Rotor Modulation (FIRM) Ablation

Study Overview
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Brief Summary
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Patients undergoing FIRM guided ablation of atrial fibrillation will undergo high resolution MRI imaging to determine correlation of underlying anatomic fibrotic regions with FIRM targeted sites for ablation.

Detailed Description
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The project will be a prospective trial involving patients consented for a clinically indicated atrial fibrillation (AF) ablation using FIRM mapping. The purpose of the study is to collect additional information before, during, and after the ablation procedure. All patients will undergo a contrast-enhance MRI scanning with gadolinium-based contrast agent prior to the procedure as it provides a 3-dimensional image of both the left atria and right atria. The primary endpoint of this study will be the presence or absence of a correlation between micro-anatomic fibrotic tracks, determined by a combination of atrial wall thickness, and local scar and fibrosis, and sites of FIRM map indicated rotor activity. Medical information will also be collected after the patients 2nd, 3rd and 6 month standard of care doctor visits. There are no additional risks associated with this protocol over and above that of the standard risk of atrial fibrillation ablation with FIRM, and those associated with the standard risk of magnetic resonance imaging with gadolinium contrast agent, but there is a small risk of the loss of confidentiality when participating in an observational study. The potential benefits includes the possibility of greater understanding of the patient's specific disease state.

Official Title
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High-resolution Contrast-Enhanced MRI of Atrial Fibrillation Patients Prior to FIRM Ablation

Conditions
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Atrial Fibrillation

Intervention / Treatment
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* Device: Catheter Ablation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with symptomatic paroxysmal or persistent atrial fibrillation undergoing clinically-indicated ablation procedure employing FIRM mapping with pre-operative MRI. Subjects must be at least 18 years of age. Exclusion Criteria: LAA thrombus present on pre-procedure TEE Unable to undergo MRI imaging Unable to receive gadolinium contrast.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Catheter Ablation Group<br>Patients undergoing FIRM guided ablation of paroxysmal or persistent atrial fibrillation with pre-procedure high resolution cardiac MRI | Device: Catheter Ablation<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of FIRM targeted sites with MRI fibrotic regions | The primary endpoint of this study will be the presence or absence of a correlation between micro-anatomic fibrotic tracks of reentry, determined by a combination of atrial wall thickness, and local scar and fibrosis, and sites of FIRM map indicated rotor activity. | Immediate post-procedure analysis | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Success or failure of electrical isolation of PV | PV analysis by intra-cardiac recordings to determine PV isolation | Immediate post-procedure | 
| Termination of AF or significant slowing of AF | Incidence of early termination or >10% increase in AF cycle length at the site of FIRM detected rotor formation and whether there is a correlation with fibrotic scar. | Immediate post-procedure | 
| Correlation of recurrence of AF six months post ablation with percentage of fibrosis ablated | Correlation of recurrence of AF six months post ablation with percentage of fibrosis ablated | Six months post ablation | 
| e. Correlation of absence atrial tachycardia or atrial flutter 6 months post ablation with connection of FIRM sites to areas of fibrotic scar or anatomic barriers. | e. Correlation of absence atrial tachycardia or atrial flutter 6 months post ablation with connection of FIRM sites to areas of fibrotic scar or anatomic barriers. | Six months post-ablation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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ablation, atrial fibrillation, FIRM