Inclusion Criteria

• Men and women, ≥ 70 years of age.
• New or established patients in the primary care practice.
• Willing to provide consent to participate in the study and to use personal health information to ascertain endpoints from the CMS Medicare Claims Database and to access data from health records.
• Health insurance by Medicare Parts A & B (Medicare Fee-for-service).

Exclusion Criteria:

• Oral anticoagulation (OAC) for any indication at the time of enrollment.
• History of atrial fibrillation (AF) or atrial flutter (AFL) as documented in the patient’s current medical problem list.
• Any condition the investigator considers a contraindication to OAC; e.g., bleeding that required medical attention or severe renal impairment.
• Any condition the investigator considers will prevent compliance with study instructions.
• Implanted cardiac devices (pacemakers, implantable cardiac defibrillators, or cardiac resynchronization therapy, and implantable loop recorders).
• History of allergy to adhesive.
• Patient is not able to wear the Zio®XT monitor or not able to apply the monitor by herself/himself or with the help of a caregiver