Subclinical Atrial Fibrillation in Older Patients.

Background: Long-term continuous electrocardiographic monitoring shows a substantial prevalence of asymptomatic, subclinical atrial fibrillation (SCAF) in patients with pacemakers and patients with cryptogenic stroke. Whether SCAF is also common in other patients without these conditions is unknown.

Methods: We implanted subcutaneous electrocardiographic monitors (St.