Relationship Between the Posterior Atrial Wall and the Esophagus: Esophageal Position and Temperature MEasurement During Atrial Fibrillation Ablation.

Study Overview
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Brief Summary
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A multimodal strategy integrating esophageal visualization with the multidetector computed tomography (MDCT) and simultaneous temperature monitoring has never been put into practice. We have developed an isodistance map (esophageal print) to depict the atrio-esophageal relationship and to analyze the esophageal position peri procedurally. The present randomized study intends to analyze the usefulness of the esophageal print in predicting local thermal heating of the esophagus.

Detailed Description
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Primary objective: to validate the usefulness of the esophageal print in avoiding temperature rises caused by radiofrequency (RF) application at the left atrial (LA) posterior wall during atrial fibrillation ablation Secondary objectives: to establish if there is a linear relationship between intraesophageal temperature rise and atrio-esophageal distance as calculated by the MDCT-derived esophageal print. to analyze the need for ablation line modification. to analyze the need for energy (power settings, ablation index, ablation time, etc.) modification. to develop a new multimodal approach to esophageal monitoring during AF/AT ablation. Interventions Pre-procedural scan and Esophageal Isodistance Print The methods for the acquisition of the cardiac MDCT and the image processing have been described in Part 1. During the segmentation process, the epicardial layer of the posterior atrial wall and the esophageal wall have been defined. The distance between these two structures is computed at each epicardial point, allowing to create an esophageal print on top of the epicardial layer. The isodistance color map uses a color scale to depict a range of distance; red being the closest (< 1 mm) and purple being the most distant (> 4 mm). Yellow, green and blue will be considered the intermediate values. Luminal esophageal temperature (LET) monitoring A multi-thermocouple temperature probe (SensiTherm, St. Jude Medical, Inc., St. Paul, MN, USA) will be advanced via transnasal or transoral access into the esophagus once the patient is under general anesthesia. When the esophageal print is close to the ablation line, the temperature probe position will be adjusted under fluoroscopic guidance before application at each pair of pulmonary veins to ensure that it overlaps the ablation line. All esophageal temperature rises above 39 °C will be documented and RF application will be stopped. Pulmonary vein ablation lines regarding Esophageal Isodistance Print Before randomization, an investigator blinded to the esophageal position will draw the PVI ablation line around both pairs of veins based on the type of AF (closer to the ostium for paroxysmal AF and wider for persistent AF).

Official Title
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Impact of Pulmonary Vein Isolation (PVI) Line Modification Based on the Multidetector Computed Tomography (MDCT)-Derived Fingerprinted Esophageal Distance to the Posterior Wall of the Left Atrium, on the Esophageal Temperature Raise Measured With an Intraluminal Esophageal Temperature Monitoring Lead. A Randomized Controlled Study.

Conditions
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Atrial Arrhythmia

Intervention / Treatment
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* Procedure: Modification of the pulmonary vein ablation line
* Procedure: Regular PVI ablation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age > 18 years. Indication for any atrial fibrillation or left atrial flutter ablation procedure. Documented episodes of atrial arrhythmia (AF/AT/AFL) Signed informed consent. Exclusion Criteria: Age < 18 years. Pregnancy. Impossibility to perform CT Scan. Impossibility to perform transesophageal echocardiography or to insert esophageal temperature monitoring probe. Concomitant investigation treatments. Medical, geographical and social factors that make study participation impractical Inability to give written informed consent. Patient's refusal to participate in the study.

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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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Single center, prospective, randomized pilot study
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Intervention group or PRINT group<br>The ablation line previously drawn will be modified regarding the esophageal print position in order to avoid RF application within the red layer of the esophageal print, which is the zone where the atrioesophageal distance is shorter. The maximal distance and the area between the original line and the modified line will be noted. In cases when ablation through the red layer is unavoidable, the delivered energy can be lowered to an ablation index (AI) of 300 regardless of the local wall thickness. If the temperature rises above 39℃, ablation will be immediately stopped, and energy will be reduced. | Procedure: Modification of the pulmonary vein ablation line<br>* The ablation line previously drawn will be modified regarding the esophageal print position in order to avoid RF application within the red layer of the esophageal print.<br>|
| Other: Control group<br>The ablation line will not be modified from the original one drawn before randomization and RF applications will follow the regular path. If the temperature rises above 39℃, ablation will be immediately stopped, and energy will be reduced. | Procedure: Regular PVI ablation<br>* Blinded to the esophageal position based on the type of AF, closer to the ostium for paroxysmal AF and wider for persistent AF<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion of participants presenting a temperature rise as measured with a luminal esophageal temperature probe during radiofrequency delivery. The temperature is measured in Celsius degrees. | Number of intraesophageal temperature rises above 39°C or absolute temperature raises of 2°C degrees. The chosen probe is St Jude | 1 day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion of patients needing ablation power or ablation time modification owing to esophageal presence in the immediate posterior wall . | Modification of the ablation parameters.Power is measured in Watts during radiofrequency application. Ablation time is measured in seconds of radiofrequency application. Both measures are provided by the electroanatomical navigation system. | 1 day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Atrial fibrillation, Atypical flutter, catheter-based ablation, radiofrequency ablation, left atrial wall thickness, atrio-esophageal relationship