AMPLATZER Cardiac Plug (ACP) Registry-Long Term Follow-up Protocol

Inclusion Criteria: * Subject must have a documented history of paroxysmal, persistent or permanent nonvalvular atrial fibrillation (documentation may include an electrocardiogram (ECG), Holter, or event recorder) * Subject must be ≥18 years of age Exclusion Criteria: * Subject with an implanted atrial septal defect (ASD) device or patent foramen ovale (PFO) device * Subject who has a history of surgical ASD or PFO repair * Subject with a history of stroke and unrepaired PFO * Subject who has moderate to severe aortic or mitral valve stenosis or regurgitation as assessed by the investigator * Subject who has a mitral or aortic prosthetic valve * Subject who has a planned ablation procedure for atrial fibrillation 30 days after the ACP implant * Subject with New York Heart Association (NYHA) grade 4 * Subject with evidence of pericardial effusion at baseline evaluation * Subject who has complex atheroma with mobile plaque of the descending aorta and/or aortic arch * Subject who has an intracardiac thrombus * Subject who has carotid disease as assessed by the investigator, requiring treatment, which includes revascularization and/or medical treatment * Subject with active infection or active endocarditis * Subject who has an acute or recent myocardial infarction (MI) or unstable angina (recent is defined as within 6 months of implant date) * Subject who has had recent major cardiac surgical procedure (recent is defined as within 6 months of implant date) * Subject with malignancy or other illness where life expectancy is less than one year * Subject who is pregnant, breastfeeding, or desires to become pregnant during their first six months of follow-up * Subject or legally authorized representative who is unable to provide informed consent * Subject who will not be able to be followed for the duration of the clinical study * Subject with any medical disorder or severe disability that would interfere with completion or evaluation of clinical study results (for e.g. uncontrolled hypertension, uncontrolled diabetes, renal failure, in situ inferior vena cava (IVC) filter)