Characterization of Arrhythmia Substrate to Ablate Persistent Atrial Fibrillation

This trial is studying a new approach to treating a type of long-lasting irregular heartbeat (called persistent atrial fibrillation) by mapping and targeting the specific areas of the heart causing the problem before performing a procedure to correct it. **You may be eligible if...** - You are 18 years or older - You have been diagnosed with persistent atrial fibrillation (an irregular heartbeat lasting more than 3 months) that is causing symptoms - Your doctor has recommended a catheter ablation procedure (a minimally invasive heart procedure) to treat your irregular heartbeat - You have had at least one episode of this irregular heartbeat documented on a heart monitor within the last 3 years - You have a certain risk score (Modified DR-FLASH score of 4 or higher) - You are able to give your informed consent **You may NOT be eligible if...** - You have previously had a catheter ablation procedure for atrial fibrillation - You do not meet the required risk score threshold Talk to your doctor to see if this trial is right for you.