Inclusion Criteria:  Adult > 18 years Able to provide written informed consent Previously enrolled in the Vanderbilt Atrial Fibrillation Registry (IVR#020669) Atrial Fibrillation Ablation Registry (IRB#110881) Early-onset Atrial Fibrillation Registry (IRB#201666) Underwent whole genome sequencing/whole exome sequencing or clinical genetic testing and based on those results meets the genetic criteria for cases and controls as defined as a Cardiomyopathy (CM) Rare Variant (P/LP rare variant in CM gene, Arrhythmia Rare Variant (P/LP rare variant in arrhythmia gene), or a Control (no rare variant in CM, arrhythmia, or other Atrial Fibrillation gene). Diagnosis of Atrial Fibrillation prior to age of 66 (</=65)  Exclusion Criteria:  -Pregnant women