Comparison of Different Ablation Surgeries on Left Atrial Reverse Remodeling in Patients With Atrial Fibrillation

This study compares different types of catheter ablation procedures — techniques that use heat or cold to destroy abnormal heart tissue — to see which approach best reverses the harmful enlargement of the left atrium (the upper-left heart chamber) in people with atrial fibrillation. **You may be eligible if...** - You are between 18 and 75 years old - You have been diagnosed with atrial fibrillation (an irregular heartbeat) that stops on its own or with treatment within 7 days of starting - You have symptoms from atrial fibrillation - You are willing to undergo catheter ablation treatment **You may NOT be eligible if...** - Your left atrium is significantly enlarged (front-to-back diameter of 50 mm or more) - Your heart pumping function is reduced (ejection fraction of 40% or less) - A scan has found a blood clot in your left atrium or left atrial appendage - You have had previous catheter ablation for atrial fibrillation Talk to your doctor to see if this trial is right for you.