Change in Inflammatory State in Patients Undergoing Transcatheter Ablation of Atrial Fibrillation

This study is looking at how a catheter ablation procedure (a treatment that uses heat or cold energy to correct irregular heart rhythms) affects inflammation in the body for people with atrial fibrillation (AFib), which is an irregular heartbeat. **You may be eligible if...** - You have paroxysmal (comes and goes) or persistent AFib - You are scheduled for an approved catheter ablation procedure - You are between 18 and 85 years old - You can give informed consent **You may NOT be eligible if...** - You are older than 85 or younger than 18 - You have a blood clot in your heart's left atrial appendage - You have severe heart failure (NYHA class IV) or a very low heart pumping function (ejection fraction below 30%) - You had a heart attack, unstable chest pain, or bypass surgery in the last 6 months - You have serious conditions like cancer, kidney failure requiring dialysis, severe lung disease, or liver cirrhosis with less than 12 months life expectancy - You cannot give informed consent Talk to your doctor to see if this trial is right for you.