Prospective Phenotyping for Genetic Subtypes of Early-onset Atrial Fibrillation

This is a prospective, case-control study that seeks to learn about the role of genetics in early onset atrial fibrillation (AF) and if genetic testing can be used to improve how the investigators treat atrial fibrillation. The study will enroll 225 participants. Eligible participants will have undergone sequencing for arrhythmia and cardiomyopathy (CM) genes. Based on those results, participants will be recruited for an outpatient research visit with testing that includes cardiac MRI, rest/stress/signal-averaged ECGs, and cardiac monitoring. If an inherited arrhythmia/CM syndrome is diagnosed, guideline-directed changes to medical care will be recommended.