A New Theory of Electrophysiological Mechanism of Atrial Fibrillation

Study Overview
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Brief Summary
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The electrophysiological mechanisms of atrial fibrillation remain disagreements. The goal of this clinical trail is to propose a new electrophysiological mechanism hypothesis of atrial fibrillation（AF）,meanwhile, the investigators sought to test the hypothesis that the superposition electrograms (SPEs) recorded during atrial fibrillation could be used as target sites for catheter ablation of atrial fibrillation.

Detailed Description
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Catheter ablation for atrial fibrillation is a promising therapy, whose success is limited in part by uncertainty in the electrophysiological mechanisms of AF. The investigators recruited 100 subjects including paroxysmal(40%) and persistent (60%) AF. Cases were prospectively treated, in a 2-arm 1:1 design, by ablation SPEs followed by pulmonary vein isolation(PVI) ablation (n=50), or pulmonary vein isolation alone (n =50). All procedures are guided by CARTO (Biosense Webster) electroanatomic mapping system and ablation is performed using open irrigated catheters with contact force (CF) sensing (Thermocool SmartTouch, Biosense Webster). Study Group underwent electroanatomic mapping during AF. Using CARTO to identify areas associated with SPEs. Radiofrequency ablation of the area with SPEs was performed, aiming to eliminate SPEs and convert to sinus rhythm or atrial tachycardia.

Official Title
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A New Theory of Electrophysiological Mechanism of Atrial Fibrillation and Catheter Ablation Therapy for Atrial Fibrillation

Conditions
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Atrial Fibrillation

Intervention / Treatment
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* Procedure: PVI + SPEs ablation
* Procedure: PVI ablation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoing a first-time ablation procedure for AF Paroxysmal AF will be defined as a sustained episode lasting > 7 days; Persistent AF will be defined as a sustained episode lasting > 7 days and less than 1 years; Long-lasting persistent AF will be more than 1 year and less than 5 years. Patients must be willing and able to comply with all peri-ablation and follow-up requirements. Patients with atrial fibrillation will to accept the procedure of ablation. Patients signed the written informed consent for the study. Patients can endure the required follow up. Exclusion Criteria: Patients with contraindications to systemic anticoagulation with heparin or a direct thrombin inhibitor. Patients with thromboembolus in left atrial appendage. Patients with left atrial size ≥ 55 mm (2D echocardiography, parasternal long-axis view). Patients allergic for contrast or iodine. Patients with the serum creatinine（SCr） >3.5mg/dl Patients with life expectancy < 12 months Patients who are in the period of pregnant

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: With additional SPEs ablation<br>Patients who undergo PVI + SPEs ablation using ThermoCool SmartTouch catheter. | Procedure: PVI + SPEs ablation<br>* electrophysiology substrate mapping is the critical difference between both groups.<br>|
| Active Comparator: Control Group<br>Patients who undergo PVI alone using ThermoCool SmartTouch catheter. | Procedure: PVI ablation<br>* electrophysiology substrate mapping is the critical difference between both groups.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Freedom from AF during follow-up | At the one-year follow-up，AF occurring in the first 3 months after the ablation (blanking period) were censored.Beyond this, any AF episode that lasted for more than 30 seconds was categorized as a recurrence. | one year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Acute success rate of AF termination during ablation procedure | Conversion of AF to normal sinus rhythm or atrial tachyarrhythmias during ablation procedure. | one year | 
| Complications | Serious adverse events included death, pericardial tamponade , cerebrovascular events, significant PV stenosis , left atrial-esophageal fistula. | one year |