Incidence of Silent Atrial Fibrillation in Patients With Clinically Silent Brain Ischemic Lesions

This study is monitoring older adults who have had silent (symptom-free) strokes on brain scans to see how often they develop undetected atrial fibrillation (an irregular heart rhythm that increases stroke risk). **You may be eligible if...** - You are 65 or older, OR 50 or older with specific heart risk factors (elevated NT-proBNP blood level or an enlarged left atrium) - A brain MRI or CT scan has shown small silent strokes or white matter changes - You have no prior history of atrial fibrillation **You may NOT be eligible if...** - You have a known history of atrial fibrillation or atrial flutter - You have had symptoms of a stroke (only silent brain findings are eligible) - You already have a pacemaker or implanted heart rhythm device - You are already on anticoagulants (blood thinners) for other reasons Talk to your doctor to see if this trial is right for you.