This is a prospective, non-randomized study to refine the Study Watch's algorithm for AF detection within both persistent and paroxysmal AF subjects. The study will also collect data from an FDA-cleared wearable ECG sensor.

Inclusion Criteria:

• At least 18 years old
• Able to read and speak English
• Able and willing to sign written Informed Consent
• Interest in participating in the study
• Subjects with a known history of AF (including persistent or paroxysmal AF)
• Without significant limitation in ability to participate in the study, in the opinion of the investigator.

Exclusion Criteria:

• Currently in a paced rhythm
• Known severe allergy to nickel or metal jewelry
• Known allergic reaction to adhesives or hydrogels or with family history of adhesive skin allergies

Subjects with a known history of AF (including persistent or paroxysmal AF)