This study focuses on people who are undergoing catheter ablation for paroxysmal atrial fibrillation. The purpose of the study is to compare 2 ablation (destruction of tissue) strategies during catheter ablation for atrial fibrillation and determine how these strategies affect the temperature and risk of injury to the esophagus. Study procedures include catheter ablation for atrial fibrillation, followed by a capsule endoscopy 2-4 days after the ablation procedure in order to assess the esophagus. The devices used in the study are approved by the U.S. Food and Drug Administration (FDA). Participants will be randomly assigned to 1 of 2 groups. The “QDOT group” will undergo temperature-controlled, very-high power, short-duration ablation on the left atrium, using the QDOT Micro ablation catheter. The “ST SF group” will undergo high-power, short-duration ablation on the left atrium, using the ThermoCool SmartTouch SF ablation catheter. Both the QDOT Micro and ThermoCool SmartTouch SF ablation catheters use radiofrequency (heat) energy to ablate tissue. The QDOT Micro catheter has additional temperature sensors that allow it to be safely used to deliver temperature-controlled higher power and shorter duration ablation lesions. This type of ablation lesion is theoretically less deep, which may lead to equivalent heart muscle ablation with less effect on deeper surrounding tissues (such as the esophagus).