Efficacy of Early Rhythm Control Therapy in Patients With Subclinical Atrial Fibrillation

This trial is studying whether treating atrial fibrillation early — before it is confirmed by a standard ECG — can reduce the risk of stroke and other complications. The study focuses on patients whose implanted heart devices (like pacemakers or defibrillators) have detected abnormally fast atrial rhythms, which may be an early sign of atrial fibrillation. **You may be eligible if:** - You have an implanted cardiac device (pacemaker, defibrillator, loop recorder, or CRT device) that has detected high-rate atrial episodes - You are 19 years of age or older - Over a 3-month monitoring period, the total time of these fast atrial episodes adds up to more than 21 hours - Your atrial fibrillation has not been confirmed by a standard ECG or Holter monitor in the past year **You may NOT be eligible if:** - Your atrial fibrillation has already been confirmed by an ECG or Holter monitor in the past year - You are already taking certain heart rhythm medications (Class Ic or III antiarrhythmic drugs) - You have had rhythm control procedures like catheter ablation or surgical maze procedures previously Talk to your doctor to see if this trial is right for you.