Foresight Intracardiac Echocardiography (ICE) System

Inclusion Criteria: * Patient is at least 18 years old. * Patient is undergoing an atrial fibrillation ablation procedure. * Patient has a transesophageal echocardiogram (TEE) within the 48 hours prior to ablation procedure to rule out left atrial thrombus. * Patient provides informed, written consent for participation in the study. Exclusion Criteria: * Patients in whom placement of an ICE catheter in the right atrium for adequate atrial visualization is not technically feasible (as evaluated and determined by the physician performing the procedure). * Patients in whom transseptal puncture is relatively contraindicated. * Patients in whom left atrial clot or dense spontaneous contrast is identified on TEE, which would increase thromboembolic risk. * Women of child bearing potential, in whom pregnancy cannot be excluded. * Patients unable to grant informed, written consent for participation in the study.