Atrial fibrillation is an abnormal beating of the heart that can lead to stroke or heart failure. Structural heart diseases are conditions that affect the heart valves or heart muscle and can cause permanent heart damage if left untreated. Sometimes people have atrial fibrillation or structural heart disease and do not know it. The purpose of this study is to evaluate two devices that can predict who has or may develop atrial fibrillation or structural heart disease based on the results of an electrocardiogram.

Inclusion Criteria:

• Retrospective Phase:
• Adults aged 40 or older.
• At least 1 ECG obtained during routine clinical care.
• Prospective Phase:
• AF Cohort:
• Adults aged 65 or older at the time of ECG.
• ECG obtained as part of a clinical care.
• Patient is able to identify a licensed healthcare provider to receive the results of the patch monitor.
• SHD Cohort:
• Adults aged 40 or older at the time of the ECG.
• ECG obtained as part of a clinical care between study start date and the end of study recruitment
• Patient is able to identify a licensed healthcare provider to receive the results of the echocardiogram.

Exclusion Criteria:

• Retrospective Phase:
• Patients who have previously requested that their data not be involved in any secondary use application such as a research study.
• Prospective Phase:
• AF Cohort:
• Any clinical or social factor that would prohibit completing the follow-up studies in a timely fashion.
• Patient currently admitted to the hospital (at time of consent)
• Permanent pacemaker or implanted cardiac defibrillator or implanted loop recorder.
• History of atrial fibrillation or atrial flutter.
• Cardiac surgery within 30 days prior to the index ECG
• Cardiac surgery planned within the next 6 months.
• Allergy to adhesive.
• SHD Cohort:
• Any clinical or social factor that would prohibit completing the follow-up studies in a timely fashion.
• Patient currently admitted to the hospital (at time of consent).
• History of SHD defined as any of the following: severe mitral regurgitation, severe tricuspid regurgitation, moderate or severe aortic stenosis, moderate or severe aortic regurgitation, moderate or severe mitral stenosis, left ventricular systolic dysfunction (LVEF ≤ 40%), or increased septal wall thickness > 15 mm.
• Allergy to ultrasound gel.